SYSTEMS FOR MONITORING FLUIDS IN NOZZLES AND FOR AGRICULTURAL SPRAYING

专利摘要:
systems for monitoring fluids in nozzles and for agricultural sprinkling modalities of a sprinkler system having sprinkler nozzles; each nozzle includes a thermistor or resistor that provides a voltage or electronic current value correlated with a local flow or temperature. a low flow rate indicates an obstruction or a blockage of fluid flow inside the nozzle or duct. the flow or temperature results between the different nozzles are compared to detect which nozzles are partially or entirely obstructed or are otherwise anomalous. in various modalities, thermistor electronics are integrated into each individual nozzle. in some modalities, by detecting a potential obstruction, the electronics create an alert and respond to the obstructed condition.
公开号:BR102015031713B1
申请号:R102015031713-1
申请日:2015-12-17
公开日:2021-04-13
发明作者:Richard A. Humpal；Dolly Y. Wu
申请人:Deere & Company；
IPC主号:

专利说明:

Technical Field
[001] This invention generally refers to the monitoring of fluid flow distribution systems having outlets. Background
[002] Fluid distribution systems apply nutrients, herbicides, paints, chemicals and other liquids such as those used in agriculture or industrial applications. For wide area spraying, the dispensing system tends to have many spray nozzle outlets, often seventy or more outlets. The ducts leading to nozzles and the holes in the nozzles are often narrow enough that the ducts or nozzles are clogged by dust and debris or by the coagulation of the spray chemical. So the spray output is no longer uniform or is an inadequate amount. Given the large number of exits, it takes time to visually monitor and fix an obstruction or clogging problem. Also, the end user or operator can have a direct view of the spray nozzles or ducts and the spray nozzle, and may not even realize that an outlet is no longer spraying properly. Additionally, the spraying task will take much longer if the operator has to stop to solve the problem. summary
[003] Various aspects of exemplary modalities are presented in the claims. The modalities include a sprinkler system having spray nozzles; each nozzle includes a thermistor or resistor that provides a voltage or electronic current value correlated with a local flow or temperature. A low flow rate indicates an obstruction or blockage of fluid flow inside the nozzle or duct. The results of flow or temperature between the different nozzles are compared to detect which nozzles are partially or entirely obstructed or otherwise anomalous. In various modalities, thermistor electronics are integrated into each individual nozzle. In some modalities, by detecting a potential obstruction, the electronics create an alert and respond to the obstructed condition. Other modalities are revealed in the detailed description, attached drawings and claims. Brief Description of Drawings
[004] The detailed description refers to the following exemplary figures.
[005] Figure 1 illustrates an example of a vehicle carrying a spray boom.
[006] Figure 2 illustrates an example of a nozzle that includes a flow sensor and the corresponding electronics.
[007] Figure 3 shows a cross section of the example in Fig. 2.
[008] Figure 4 illustrates another cross-section of the example in Fig. 2.
[009] Figure 5A illustrates a front view of an example of a thermistor.
[0010] Figure 5B shows a side view of the thermistor example in Fig. 5A.
[0011] Figure 5C illustrates a front view of an example of a thermistor.
[0012] Figure 5D illustrates a side view of the thermistor example in Fig. 5A.
[0013] Figure 6 illustrates an example of a pair of thermistors in a nozzle cavity.
[0014] Figure 7 illustrates an example of fitting for thermistors.
[0015] Figure 8 illustrates an example of a circuit to measure a voltage across a thermistor located in a fluid path.
[0016] Figure 9 illustrates another example of a circuit for measuring a voltage across a thermistor located in a fluid path.
[0017] Figure 10 illustrates an example of a flowchart for measuring a voltage, deriving a thermistor resistance and / or verifying variance.
[0018] Figure 11 illustrates an example of a circuit to measure a current through a thermistor.
[0019] Figure 12A illustrates an example of a circuit to generate a voltage pulse across a thermistor.
[0020] Figure 12B illustrates another example of a circuit to generate a voltage pulse across a thermistor.
[0021] Figure 13A illustrates a performance graph of an example of thermistor resistance and current versus temperature.
[0022] Figure 13B illustrates a performance graph of an example of a thermistor current duty cycle versus voltage pulse.
[0023] Figure 14 illustrates an example circuit to measure a voltage across a thermistor located in a fluid path.
[0024] Figure 15 illustrates an example of a differential circuit for measuring a voltage across a thermistor located in a fluid path.
[0025] Figure 16 illustrates an example of a differential circuit for measuring a voltage across a thermistor located in a fluid path.
[0026] Figure 17 illustrates an example of a nozzle inlet section having an optional fluid flow sensor and strainer.
[0027] Figure 18 illustrates an example of a multi-head nozzle having an optional fluid flow sensor and strainer.
[0028] Figure 19 illustrates an example of boom section valves having a fluid flow sensor.
[0029] Figure 20 illustrates an example of a nozzle turned to a position where fluid flows to two outlets.
[0030] Figure 21 illustrates an example of a nozzle rotated to a position where fluid flows into any outlets. This position helps an operator to clear a nozzle clog.
[0031] Figure 22 illustrates an example of a lightweight fiber suspension boom, behind which are nozzles having fluid flow sensors. Wiring of the electronic signal is routed into the void of the tubular boom.
[0032] Figure 23 illustrates an example of a metal or fiber lance having trusses, among which are nozzles having flow sensors. The sensors communicate either wirelessly or over cables (e.g. CAN bus) with a processing circuit such as a CPU or central computer.
[0033] Figure 24 illustrates an example of a lightweight metallic or composite fiber boom, under which nozzles are fitted with fluid flow sensors. Wiring of the electronic signal is routed to a boom void. Detailed Description
[0034] This invention provides examples of modalities where a suitable material such as thermistors or resistors (collectively, "thermistor") is placed in a fluid in a spray nozzle or duct; the thermistor operates as a flow sensor. The thermistor is used both to heat the spray fluid and to provide a measurement value (e.g. current or voltage) that is directly related to a temperature of the local fluid in the spray nozzle or duct. The measured value determines the resistance of the thermistor, and temperature can then be derived from the resistance based on the Steinhart-Hart equation or a temperature coefficient equation for a particular material. The local material is heated by the thermal energy generated when a current passes through a resistance of the thermistor. When the fluid is moving quickly beyond the thermistor, the thermistor does not have enough time to overheat, clutch or become defective. The flowing fluid is similar to an isotropic bath or constant temperature so that the thermistor dissipates its heat in the bath and has no time to heat up. However, if there is an obstruction, the fluid is stagnant and the local fluid is heated by the thermistor and the thermistor remains hot and its resistance changes. The measured current or voltage values or resistance values derived from the many spray nozzles or ducts are compared to detect anomalous conditions in one or more of the spray nozzles or ducts. Alternatively, a clogged condition is assumed to have occurred when it is no longer possible to maintain a current at a particular voltage value. The voltage or currents went beyond predetermined threshold values. By detecting a predetermined amount of variance between the different nozzles, an indication of reduced flow, fluid obstruction or other defect is generated, and then several actions occur subsequently or can be selectively activated in an attempt to remove the obstruction. For example, a sieve or filter in the nozzle traps dirt and particles; and the nozzle is periodically turned. Or the opposing valves in a nozzle are pulsed to act as a plunger over the fluid to expel the obstruction particles.
[0035] To provide concrete examples, the system and methods are described in the context of an agricultural sprinkler having many nozzles. Sprinklers include spray equipment attached to aircraft or towed by vehicle, self-propelled sprinklers, irrigation sprinklers, and so on. A variance between the measured values for the nozzles is used to detect clogging or other potential problems, such as a wrong nozzle tip, wrong nozzle position, cracked nozzles, and so on. Apart from agricultural end uses, industrial nozzles used to paint surfaces, distribute liquids or edible oils can also benefit from the examples of modalities described here.
[0036] Figure 1 illustrates a top view of an example vehicle 20 towing a chemical storage tank 22 and also a spray boom 30 having many spray nozzles 40. In other embodiments, boom 30 is mounted on front 24 of vehicle 20, where the spray nozzles 40 are more visible to an operator, but may still be obstructed from view especially around night time. Fluids from a chemical tank 22 are transferred through manifolds, fluid distribution tubes and other supply lines that are attached to the boom 30. The boom side 30 also includes main section open / close valves 44 (eg Fig. 19, 24) that control fluids for the fluid pipe 42 (eg Fig. 24) and subsequently for the nozzles 40. The thermistor 50 and the accompanying electronics are located inside each nozzle 40 and optionally also on the section valves opening / closing main 44. Alternatively, the electronics are located in a boom section controller, remote from nozzles 40.
[0037] In various modalities, the thermistor 50 is placed near an inlet of a nozzle 40, where the entire amount of fluid for a nozzle flows beyond the thermistor 50. Fig. 2 illustrates an example of nozzle mode 40 where fluid flows from a distribution pipe 42 to the inlet 34, then to the orifice 38 near the inlet to the nozzle 40. On each side of the orifice 38, there are nozzle tubes 36A and 36B (collectively "36"); 36A and 36B have a common central geometric axis (parallel to the tube) and tubes 36 are perpendicular to the circular ring 37 which is used to mount the nozzle 40 in a fluid distribution tube 42. The nozzle 40 contains a thermistor 50 mounted on a orifice neck 38, approximately between the nozzle tubes 36 having solenoid valves 362A, 362B or other walls on each end of the tubes 36; the valves allow the fluid to flow from inlet 34 and orifice 38 to other ducts or chambers in nozzle 40; the other chambers include a turret 32 which is connected to the nozzle tube 36. The fluid flows past the thermistor 50 which is placed approximately perpendicular to the direction of fluid flow; there is a projection on which the terminal conductors of the thermistor 50 are hooked; or there is a fit in an inner wall of the orifice 38 in which a thermistor 50 is plugged. An example of thermistor 50 is illustrated in figures 5A (front view) and 5B (side view); the dimensions are in millimeters. An example of a smaller thermistor 50 is illustrated in figures 5C and 5D. There is an optional nylon or plastic sieve or above or below thermistor 50 to trap particles that may enter undesirably into the nozzle 40. Alternatively, to prevent obstruction of the fluid flow, the thermistor 50 is recessed according to an inner surface of the nozzle tube 36 or orifice 38. Each end terminal of the thermistor 50 is connected to an electronic trace or wire 33 that goes to the electronic circuit 382. The electronic signal strokes or wires 33 stamped along a surface of the nozzle 40 or the strokes and wires 33 are (hermetically) sealed and move along a small duct that is shown on the back of the nozzle tube 36, and return back into the body of the nozzle 40. The electronic circuits 382 are located in a moisture-proof chamber inside the nozzle 40. In other embodiments, the signal traces 33 travel to a bus (eg CAN bus) to a signal processing matrix or sectional controller external to a group nozzles 40. In the example in Fig. 2, thermistor 50 is located in the fluid, but not subsequent processing circuits 382. Thermistor 50 is resistant to moisture or water or hermetically sealed in ceramic, metal, semi-plastic or polymer or other material that readily conducts heat (eg cold polyelastomers that conduct heat, but not electrical signals).
[0038] In the example of Fig. 2, there are additional elements such as actuators and valves 362A, 362B that enable or disable fluid flow; they also play a role in a method of displacing an obstructed mouthpiece as described later in this invention. Examples of actuators include 362A, 362B solenoid valves, electromagnetic spring coil, pneumatic lever, bellows, and so on. The turret 32 is manually rotating or rotating by motor and fixed to a lower end of the nozzle tube 36; alternatively, turret 32 is attached to a rotating plate 312 which is electronically controlled. The turret 32 includes a stocky cylindrical body. The turret 32 also contains passageways that channel fluid from the nozzle tube 36 to the nozzle outlets. The nozzle outlets 1 - 6 are located on the periphery of the turret 32. The turret 32 is manually rotated if there is no plate 312 or automatically rotated if there is a plate 312 and a corresponding motor to rotate the plate 312 (eg stepper motor ). Figures 3 and 4 show a cross-section of the nozzle example in Fig. 2; Fig. 3 exposes the nozzle 40 in a plane that is slightly to one side of the center of the nozzle tube 36 along the short geometric axis or diameter of the nozzle tube 36. The turret 32 contains electronic circuits 382 to operate and monitor the thermistor 50, sensors (eg by pressure) of currents and voltage, and the turret rotation position. Electronic circuits 382 are located in a moisture-proof compartment in turret 32. Traces or electrical wiring embedded in the wall of nozzle 40 electrically connect thermistor 50 to electronic circuits 382.
[0039] In various modalities, the thermistor (s) 50 is (are) placed (s) in an inner duct or orifice of a nozzle 40, where only a portion of or all the amount of fluid for a nozzle, it flows beyond each thermistor 50. For example, the nozzle 40 of figure 4 can be operated in multiples in such a way that only one nozzle outlet or multiple and outlets release fluid. A thermistor 50 is thus located in each individual section of the nozzle 40, where fluid can flow. Fig. 4 illustrates another cross-section of the nozzle example of Fig. 2, exposing the nozzle 40 in a plane of the nozzle tube 360 along its major geometric axis. A circular mounting ring 37 allows to mount the nozzle tube 36 in a fluid distribution tube 42. The nozzle tube 36 has an inlet 34 that supplies fluid to an orifice 38, on each side of which are solenoid valves 362A and 362B in nozzle tube 36. If solenoid valves 362A and 362B are in an open position, the fluid then flows into vertical connection pipes or ducts 340 and 342 in turret 32. Vertical connection ducts 342 and 340 have release holes 346 and 344, respectively, which are located near the lower end of connection ducts 342 and 340. Depending on the position in which the turret 32 is rotated, the release holes 346 and 344 are coupled with horizontal channels that are coupled with one or more openings (330A, 330B, 331) connected to the nozzle outputs 1 - 6. This is diagrammatically shown in figure 21, the selected nozzle output (s) 1 - 6 is (are) positioned (s) for receive fluid from the nozzle tube 36 when horizontal channels, internal conduits A and / or B ends are aligned with an opening (330A, 330B, 331) for an output 1 - 6.
[0040] In Fig. 4, there are examples of thermistors 50 located just below the release holes 346 and 344. The vertical height of the release holes 346 and 344 are different in order to match the horizontal channels that are aligned with a opening (330A, 330B, 331) of an outlet 1 - 6. Thus, the vertical location of two thermistors 50 in the respective vertical connection ducts 342 and 340 are also asymmetrical, as shown in Fig. 4. Figure 6 illustrates an enlarged view thermistors 50 and an outer housing 51 retaining thermistors 50. The thermistors are at the top of the two columns in the housing 51. A bottom surface 53 forms a top cover for the chamber containing the electronic circuits 382. The electrical conductors 55 from the thermistors 50 are visible on the bottom surface 53. Electrical conductors 55 plug into circuit fittings 57 on the printed circuit board for electronic circuits 382, as shown in figure 7. In some models Accordingly, thermistors 50 have an outer (overmolded) housing as illustrated in Fig. 5d.
[0041] In Fig. 7, the outer housing 51 includes two towers that conjugate and fit in the vertical connection ducts 342 and 340. The two towers are welded (eg welded to ISO 472 plastic), welded by injection, etc., to a lower inner surface of the respective connection ducts 342 and 340. As 3-D printing improves, this serves as an alternative manufacturing method for thermistor 50, housing 51 and other parts inside the nozzle turret 32. The material for making the outer shell 51 includes moisture or water resistant material such as ceramic, semi-plastic or polymer or other material that readily conducts heat to the thermistors 50 to perform their function (eg cold polyelastomers that conduct heat, but not signals but can still be watertight sealed or bonded to a nozzle 40 material (eg plastic or polymers).
[0042] Figure 8 illustrates an example electronic circuit to monitor the fluid flow characteristics to detect an obstruction or partial obstruction or some other anomaly in the fluid flow. Thermistor 50 is placed in the fluid, but the extreme terminals 52 and 54 of thermistor 50 are electrically wired in circuits that are located anywhere on nozzle 40 or located remotely from nozzle 40. Terminal 52 is electrically connected to earth or to some other fixed reference. Terminal 54 is electrically coupled to a fixed current source 56 so that a substantially constant current (eg within 90%) flows through thermistor 50. The voltage at terminal 54 is measured or the differential current across thermistor 50 is measured by a voltmeter circuit. For example, the voltage value is received by an analog buffer and then digitized, and the digitized signals are sent to a circuit | processor circuit or logic unit to compute the resistance of the thermistor 50 and to infer the temperature of the fluid.
[0043] Figure 9 illustrates another example of electronic circuit to monitor fluid flow characteristics. The voltmeter in Fig. 8 includes replacing it with a preamplifier 58 having a high impedance input so that the fixed current flows through thermistor 50 and not to preamplifier 58. The preamplifier 58 amplifies the voltage measured over thermistor 50 and improves the signal-to-noise ratio. An analog to digital converter (ADC) converts the analog voltage from preamplifier 58 to digital output bits for further processing by a processor or computer that can calculate the resistance and temperature of the thermistor 50 and infer the fluid temperature.
[0044] With respect to the operation of Figs. 8 and 9, figure 10 illustrates a flowchart of an example method that supplies a constant or known amount of electrical current I through thermistor 50. The amount of electrical current I is selected in part to keep thermistor 50 in the operational region and to avoid going beyond the range and maximum or minimum operation of the thermistor 50 ("barrier"). While the substantially constant current is put through thermistor 50, voltage V is monitored along thermistor 50, which then provides the resistance value R through Ohm's law, R = V / I. Then the calculated value of R leads to a determination of the temperature T for the given material, where the temperature T and the resistance R are related, for example, by the Steinhart equation.
[0045] There are multiple optional operating modes. For example, it is also possible to measure the current I through the thermistor 50 in addition to the voltage V along the thermistor. For example, the current can be measured by a current sensing resistor. Current I and voltage V lead to a calculation of the instantaneous value of R with Ohm's law, and then the temperature T is computed from the value of R. Alternatively using precision circuit elements, current I is not measured, but taken as constant. The circuit to generate current I is external to the flowing fluid and generates current I with temperature-independent components (eg precision resistor) so that current I remains constant within 95% or 99% and thus can be taken as a fixed value in calculations. In still other modes of operation, calibrations are carried out a priori and the constant current I and the performance of other circuitry are correlated with a known temperature (e.g. using a thermometer). Any observed stock deviations or displacements are stored in memory so that they can be taken into account when calculating resistance and temperature values during regular values, which can provide a more accurate estimate of the true temperature. In addition, calibration offsets reflect manufacturing variations between the thermistors and other electronics positioned in the different nozzles; these types of manufacturing variation offsets are also stored. Before comparing the results from the different nozzles, the calibrated displacements are subtracted or taken into account to normalize the results between the different nozzles. When an abnormal temperature value T is observed, a clogging alert is generated. Alternatively, instead of calculating the temperature T, to determine anomalies among many nozzles, it is sometimes sufficient to monitor a variance between the different values of voltage V when the same amount of current is fed to all the respective thermistor nozzles. Due to current conservation, the same amount of current can be sent to all thermistors even over a long length of wiring. When an abnormal voltage V value is observed between the different nozzles, a clogging alert is generated.
[0046] In a closed area such as inside a nozzle cavity, the heat generated by the thermistor can still accumulate even if there is a flow of fluid. To avoid possible barrier formation or overheating of the thermistor 50, the current I through the thermistor 50 is switched off, for example, at selected intervals or when the boom is raised or the vehicle decelerates or stops or makes a turn. If the fluid flow and the actuation of the nozzle valve operate in a PWM mode, the current release I can also be synchronized with the valve actuation PWM signals. During the "OFF" periods of no current, the self-generated heat from thermistor 50 is then dissipated. Subsequently, the current is released again to the thermistor 50 for a period of time, during which new measurements are taken again to detect a clogged or partially clogged condition.
[0047] Figure 11 illustrates an example circuit type where a pulsed voltage Vpulse along thermistor 50 generates an I-thermistor current through thermistor 50. The average magnitude of the I-thermistor current is kept constant (within 90 - 95%) due to the action of a feedback loop that modulates the pulse width of Vpulse along the resistance of the thermistor 50 as the resistance may vary with temperature. It is also possible to keep the pulse width (or frequency) of Vpulso the same, but the amplitude is varied. Thermistor 50 is located in the fluid, but the rest of the circuits are external to the nozzle 40 or in a separate dry compartment inside the nozzle 40. A terminal 52 of the thermistor 50 is located at a reference voltage such as earth. The other terminal 54 of thermistor 50 is electrically connected to a current sensor R-sensor 60. The other end of R-sensor 60 is moved by a voltage pulse or a periodically switched voltage V-pulse 64. A sensing block 62 is connected in parallel with R-sensor 60 to measure the differential voltage across R-sensor, in order to determine the current I-sensor through R-sensor 60 (and thus also the current I-thermistor through thermistor 50) . A comparator 68 is electrically connected to the sensing block 62 to check whether the current I-sensor (or I-thermistor) is comparable to a desired current I-desired. Comparator 68 is connected to a modulator 70 that modifies either the duty cycle (PWM) or the amplitude (PAM) of V-pulse. In implementation, modulator 70, comparator 68, and other circuits include software and / or electronic circuitry. For example, comparator 68 includes an analog current amplifier comparator, a current / voltage ramp and threshold detection, a digital circuit comparator, or a software comparison of the two values. As another example, the V-pulse or PWM voltage 64 includes an implementation such as that illustrated in figure 12A, where a software processor or pulse generator sends a pulse signal to a buffer 72 that drives a switch 74 to electrically connect a Ventilated voltage to terminal 54 of thermistor 50. In Fig. 12A, buffer 72 controls a switch 74 (eg MOSFET) that electrically connects or disconnects a Ventilated (voltage supply) to terminal 54 of thermistor 50. The other thermistor terminal 50 is electrically connected to earth or some other fixed reference voltage. Buffer 72 also includes current sensing to monitor a current going through thermistor 50. For nozzles 40 that are operated under pulse width modulation (PWM) control to spray and release fluids, the PWM signal can also be used to command and modulate the input of the buffer 72. The output of the buffer 72 is modulating a signal by commanding the MOSFET signal port 74 to switch on or off switch Y to connect or disconnect fan from thermistor 50. In this example, switch 74 operates as a linear switch and vented pass and source currents to the load thermistor 50 when the MOSFET operating voltage values are reached. If the MOSFET is an N-channel FET, the conditions for venting are Vg - Vs> Vt and Vgs - Vt> Vds, where Vg is the gate voltage, Vs is the source voltage, Vds is the voltage across the drain and source and Vt is the threshold voltage of the FET. The polarity is therefore switched if the MOSFET is a P-channel FET, Vs - Vg> Vt; Vsg - Vt> Vsd.
[0048] In an example of a method of operating the pulsed circuit circuit configuration in figures 11 and / or 12A, the I-pulse current is kept substantially constant within 90 - 95% while the current through and voltage across the thermistor 50 are monitored and measured. Since the current is a pulse, there are different ways to adjust it and still maintain a constant current. For example, either the amplitude (I-avg over multiple pulses) and / or the I-pulse duty cycle in thermistor 50 can be kept constant. However, the value of V-pulse (Fig. 11) or V-input (Fig. 12A) still varies because the thermistor resistance 50 changes with temperature or other environmental variations based on Ohm's law; the voltage still varies because V = I x R even if the current can be kept constant. For example, if V-input is a battery whose voltage is switched to terminal 24, the value of V-input changes depending on the charge on the battery. I-pulse or I-avg current is detected and measured by measuring a voltage across a Rsensor sensor resistor that is in series with the resistance of the Rtermistor thermistor. The detected current Isensor must reflect the value of I-pulse, or an average of I-pulse (I-avg), which is passing through thermistor 50. If the magnitude of I-avg is different from a desired value, the cycle service cycle of the V-pulse (Fig. 11) or the service cycle for the V-input switch (Fig. 12A) is adjusted. The duty cycle can be adjusted upwards or downwards until the current through thermistor 50 returns to its desired value even when the temperature and Rtermistor vary.
[0049] Temperature and variance among the results of nozzles 40 are derived by the following example method. The detected current reflects the amount of current through the thermistor 50 so that approximately, Isensor = I-pulse = V-input / (Rsensor + Rtermistor), without contributing to effects such as the switched-on resistance or wiring resistors. Alternatively, average values are computed, Isensor = I-avg = average <V-input / (Rsensor + Rtermistor)>. When the V-pulse or Vented duty cycle is adjusted, this resembles an apparent variation (delta-V) in the voltage across thermistor 50 or that delta-Rtermistor = delta-V / I-avg = delta-V / I-pulse. The temperature variation delta-T is obtained from delta-Rtermistor, using the equations of Steinhart or tempco. The variation in temperature or the current temperature T (eg calculated from delta-T and beyond the temperature) is compared between nozzles 40. Alternatively, if the amplitude of the current between nozzles 40 is uniform, the variance between nozzles 40 is determined from the variation in the V-pulse or V-input duty cycle, or the variation in the average value of V-pulse or V-input.
[0050] In another example of a method of operating the pulsed mode circuit configuration in figures 11 and / or 12A, the I-pulse current is again kept substantially constant within 90 - 95% while the current and voltage are monitored and sampled only when current flows through thermistor 50 ("ON" mode). When switch 74 is OFF, signals are not sampled. In this case, Isensor, Ventrada are simply taken as constant values during the period of time when switch 74 is ON. The detected current Isensor reflects the amount of current through thermistor 50 so that approximately, Isensor = V-input / (Rsensor + Rtermistor), without contributing to more effects such as the switched ON resistance or wiring resistances. Ventilated varies as the Rtermistor resistance varies with temperature, which resembles an apparent change (delta-V) in the voltage across thermistor 50 or that delta-Rtermistor = delta-V / I-sensor. The temperature variation delta-T is obtained from -Rtermistor, using the equations Steinhart or tempco. The temperature variation or the present temperature T (eg calculated from delta-T and beyond temperature) is compared between nozzles 40. Alternatively, the variance between nozzles 40 is determined from the variation in the value of V-input .
[0051] Another example of monitoring for unexpected results is to do an initial calibration of current and voltage conditions at nozzles 40 or when nozzles 40 are known to be functioning properly. If the initial amount of current in the thermistor 50 is a certain X value at a particular amplitude of the V-input voltage, then any operational variations desired to keep that amount of current X almost constant (eg within 95%) provide an indirect method of monitor the temperature of the thermistor 50 and its surrounding fluid. So if V-input is initially set to a predetermined setpoint, the current through thermistor 50 is measured by a sensing resistor to obtain Isensor (eg 100mA, 200 mA) through thermistor 50. As the temperature takes or falls, the value of V-input to keep Ifixo at the calibrated value Isensor also varies. That is, the variable value of V-input is correlated with the variable value of the temperature. However, if any nozzle 40 has a variable value not usually large, this tends to indicate that something is wrong with the nozzle.
[0052] Figs. 11 and 12A can also be taken as an example illustration of electronic circuits having a thermistor 50 that includes an NTC power thermistor with a negative temperature coefficient that exhibits a wide variation in resistance corresponding to variations in the temperature of the thermistor body. Thermistor 50 includes off-the-shelf devices. Alternatively, they are custom made and stamped onto an inner surface of nozzle 40 near inlet 34; the thermistor material includes metal oxides of manganese, nickel, cobalt, copper, iron and other metals. The thermistor material includes a mixture of two or more metal oxides and a binder material; then it is pressed in a desired configuration such as one that matches the contours of the upper part of the orifice 38. The resulting material can be sintered at elevated temperatures. By varying the types of oxides, the sintering time and temperature as well as atmospheric gas, a thermistor 50 having a particular performance curve and resistance value can be manufactured that is suitable for the fluids used in a specific application or for a range of agricultural crops.
[0053] Figure 12B illustrates another circuit modality to detect a fluid flow or a clogged condition by detecting how difficult it is to maintain an average constant current or average square root (RMS) target in a temperature sensor (eg thermistor 50) ; alternatively, by comparing the variance between nozzles to maintain the constant average / RMS current, an operator can isolate a defective nozzle. The value of the average current or RMS is with respect to time. Fig. 12B illustrates a generalized circuit diagram where a voltage pulse Vpulse is generated over a thermistor 50 which is located in the fluid path. Pulse is generated from a voltage pulse source, a switching power supply, or periodically switching to one or more different fixed voltages (e.g., Ventilation in Fig. 12A). The amplitude of Vpulso is kept substantially constant (e.g. 90 - 95%); alternatively, even though the amplitude may vary, it varies substantially the same (within 95%) for all nozzles 40 having circuits operated from the same power source. Vpulso generates a variable current (pulse through each thermistor 50. Circuit block 49 measures an average current or an RMS current ("Average") through thermistor 50, such as carrying a capacitor or using a Rsensor sensor resistor and filtering the voltage across Rsensor through an RC filter circuit. When Immedia departs from the Target value, the Vpulse duty cycle D is adjusted to try to move the thermistor current back to Target. When the temperature is too high (indicating a stagnant fluid condition) to maintain the Immediate current at the Target value, the required duty cycle D can go beyond a threshold threshold Do, then a flow restriction is assumed (see figure 13B, upper right quadrant). Since there is a continuum of values for duty cycle D, D also provides an indication of the flow rate, degree of clogged condition or the type of fluid flow restriction causing a change in resistance of the thermistor 50. Calibration or love Thermistor stranding is initially and / or continuously performed to determine an appropriate Do value at a particular time or period of time. Using precision calibration constants (eg difference in resistances for thermistors or off-shelf temperature sensors), and an empirically determined lookup table, it is possible to correlate the magnitude of the duty cycle D with stored constants to determine a more accurate value of the flow for each nozzle 40.
[0054] Figure 13A illustrates a performance graph of an example of current versus temperature of a thermistor 50 such as that shown in Figs. 8 - 12A. The current (in mA) through the thermistor 50 and the resistance (in ohms) along the thermistor 50 are plotted on the y-axis as a function of the temperature (in Celsius) of the thermistor on the x-axis. Resistance ranges from about 300 ohms to less than 10 ohms between -20 to +60 degrees Celsius. Examples of thermistor include rods, beads, doped ceramics or semiconductors having NTC or negative PTC coefficients or negatives. Different modalities include thermistors with either positive or negative temperature coefficients. For agricultural applications, a temperature range of 0 - 20 degrees Celsius is often of the greatest interest because the fluid is usually chilled or cooled. A suitable choice for a particular thermistor 50 depends on the types of fluids and operating temperature range of interest.
[0055] Figure 13B illustrates a graph showing examples of results of implementing a circuit such as the one in Fig. 12B together with the thermistor characteristics shown in Fig. 13A. The polarity of the implementation (e.g. positive or negative, increasing or decreasing values) in the graph is arbitrary depending on the type of thermistor 50 or another temperature sensor. The geometric axis x represents the duty cycle D of Vpulso; below a certain duty cycle, the fluid in a nozzle 40 is not draining properly or something else may be wrong with the nozzle. The lower threshold Do is obtained by performing a calibration of the thermistors 50 such as during manufacture or periodically during the spraying operation when nozzles 40 are known to be flowing properly. For example, Do is the lowest duty cycle D that is obtained of all nozzles 40, and Dlimite is the highest duty cycle D of all nozzles 40, under a range of operating conditions (eg for all fluid temperatures and pressures). Other means of defining Do and Dlimite include taking the 4 - 5 sigma values by assembling the average duty cycle D. Still other modalities include using duty cycle results D from only selected nozzles from the complete set of nozzles 40. Likewise, for the geometric axis y, which represents a current in the thermistor 50, a lower current (I-baseline) and an upper current (I-limit) are obtained by sampling all the thermistors 50 of the nozzle 40 over a range of conditions. operation.
[0056] A thermistor 50 in a nozzle that properly operates 40 at ambient or external temperature will operate with around a target current value, which is maintained by a particular duty cycle D between Do and Dlimite. The current through a thermistor 50 is maintained at substantially (90 or 95%) the target value. However, if the duty cycle of Vpulso D needed to maintain Ialvo is below Do or above Dlimite, this indicates that something in the nozzle is not working properly or the fluid is becoming excessively hot or cold. So, if a nozzle 40 is operating in a region represented by the crosshatched quadrant in the graph in Fig. 13B, where the current in a thermistor 50 is beyond Unlimited and the Vpulso PWM duty cycle is below Do, it is assumed that the fluid flow has stopped in the nozzle or the nozzle is in a clogged condition. The graph in Fig. 13B can also be used to map or establish a fluid flow table for a nozzle 40; the exact values for the current versus duty cycle correlate with a flow. Additional variables such as flow pressure in a valve of the master section or flow pressure (pressure sensing in the membranes) for each nozzle 40 are added to the graph variables in Fig. 13B to help make a more accurate determination of flow, size droplet expected, and so on.
[0057] In an example of operation of a temperature sensor or thermistor 50 using the circuit of Fig. 11, 12A or 12B, Ialvo can be 300 mA in a Vpulse duty cycle of 30% where the Vpulse amplitude is fixed . As the temperature increases, the resistance of the thermistor decreases to a negative RTC. Based on Ohm's law, I = V / R, the current in thermistor 50 will also increase since the Vpulse amplitude is fixed. By reducing Vpulso's duty cycle, the current will decrease back to its target baseline value, Target. However, if the temperature continues to rise, at some point the service cycle will reach its Do limit (eg figure 13B), a condition that indicates a flow restriction or other problem with the nozzle 40. The value of the instantaneous service cycle is of the corresponding current can be used to calibrate a degree of flow restriction or flow.
[0058] It is also possible to implement several of the aforementioned circuit designs at a transistor level, for example, implemented as stamped electronics or flexible circuits that conform to a 40 nozzle shape. Figure 14 illustrates an example circuit circuit transistor level 100 to generate a constant current through thermistor 50 and monitor changes in temperature using thermistor 50 which is located in the fluid path at a nozzle 40. In addition to thermistor 50, the rest of the circuit is located remote and out of the fluid . Circuit 100 includes an Icurrent current generator source current for thermistor 50. Icurrent is generated by a current-mirrored circuit leg 102 formed by diode-mirrored transistors in stacked transistor legs of two or more cascading levels 102 and 104. The port terminals of the respective diode (leg 102) and MOSFET (leg 104) are electrically connected. The cascade provides high impedance to generate a more constant current. To reduce variations, diode-connected transistors (eg MOSFETS) polarize a Ro precision resistor (eg 1%) or a resistor having similar material or the same as the thermistor 50. The voltage across thermistor 50 is released at an input high impedance (eg MOSFET port) of a preamplifier with a gain of G. The output of the preamplifier is G x V output, which is digitized by an ADC and the output bits are sent to a processor. Anomalous values or variations in the product G x V outflow that exceed a predetermined threshold are indicative of a possible problem in a nozzle 40. Alternatively, problems are detected based on a variance of the values of V out or of (G x V out) between the nozzles 40 Preliminary calibration is performed to account for manufacturing variations in the precision resistor, the G-gain, the transistors, or nozzles 40 due to their location on the boom or fluid distribution tube (eg at the fluid source). If a temperature value is desired, the current Icurrent can also be monitored and measured using a sensing resistor in series with the precision resistor Ro so that the resistance of thermistor 50 can be calculated from Rtermistor = Output / Icurrent. Then the temperature is inferred from the Rtermistor.
[0059] Figure 15 illustrates at least two possible circuit operations. In a first method, Fig. 15, illustrates a distributed transistor level circuit 100 to generate a constant current through thermistors 50 and to monitor variations in temperature using thermistors 50 which is located in the fluid path at a nozzle 40. In addition of the thermistors 50, the rest of the circuit is located remote from the nozzles 40 and outside the fluid path. Circuit legs 102, 104, and 106 are located on a central section controller for a group of nozzles. Legs 104 and 106 are electrically connected (eg via CAN bus) to a corresponding thermistor 50 which is located in an individual nozzle 40. In Fig. 15, only two thermistors 50 are illustrated, but the current mirror (ie, legs 104 , 106, etc.) can be replicated many times without appreciable performance degradation. Thermistors 50 are all nominally the same (although labeled R1 and R2 in Fig. 15). Circuit 100 includes an Icurrent current generator source current for thermistors 50. Icurrent is generated by a current mirrored circuit leg 102 formed by mirrored diode connected transistors to transistor legs stacked on two or more cascading levels 104 and 106. The port terminals of the respective diode (leg 102) and MOSFET (legs 104, 106) are electrically connected. The cascade provides high impedance to generate a more constant current. To reduce variations the diode-connected transistors polarize a precision Ro resistor (eg 1%) or a resistor having similar material or the same as the thermistor 50. The voltage across each thermistor 50 is launched at a high impedance input ( eg MOSFET port) of a preamplifier (eg Fig. 14) with a gain of G. The output of the preamplifier is G x V output, which is digitized by an ADC and the output bits are sent to a processor. To reduce the amount of circuitry, a multiplexer can channel several preamplifier outputs as inputs to the ADC for sampling and digitization. Anomalous values or variations in the product G x V output for each thermistor 50 (nozzle 40) that exceed a predetermined threshold are indicative of a possible problem in a particular nozzle 40. Alternatively, problems are detected based on a variance of the values of V out or (G x V out) between the nozzles 40. Preliminary calibration is performed to take into account manufacturing variations in the precision resistor, the G gain, the transistors or nozzles. 40 due to its location on the fluid distribution boom or tube (eg at the fluid source). If a temperature value is desired, the current Icurrent can also be monitored and measured using a sensing resistor in series with the precision resistor Ro so that the resistance of thermistor 50 can be calculated from Rtermistor = Output / Icurrent. Then the temperature is inferred from the Rtermistor.
[0060] In a second method of operating the transistor circuit 100 in Fig. 15, differential signals from two thermistors 50 are sampled in order to cancel ground jump or other signal failures and to improve the signal-to-noise ratio. Fig. 15 illustrates a transistor level circuit 100 to generate a constant current through two thermistors R1 and R2 and to monitor temperature variations based on the two thermistors R1 and R2 that are both located in the same fluid path in a nozzle. 40. The resistance value of the two thermistors differs: eg R1 is much higher than R2. In addition to thermistors R1 and R2, the rest of the circuit is located remote from the fluid such as those inside a dry compartment at nozzle 40 or outside nozzle 40. Legs 104 and 106 are electrically connected to a corresponding thermistor R1 or R2. Circuit 100 includes an Icurrent current generator source current for thermistors R1 and R2. Icurrent is generated by a current mirrored circuit leg 102 formed by mirrored diode transistors in stacked transistor circuit legs of two or more cascading levels 104 and 106. The respective diode (leg 102) and MOSFET port terminals (legs 104, 106) are electrically connected. The cascade provides high impedance to generate a more current constant. To reduce variations, diode-connected transistors polarize a precision Ro resistor (e.g. 1%) or a resistor having similar material or the same as thermistors R1 and R2. The voltages V1 and V2 along each thermistor R1 and R2, respectively, are launched at a high impedance input (eg MOSFET port) of a preamplifier or a differential amplifier 110 with a G gain. The voltages are V1 = Current x R1; V2 = Current x R2. The output of the differential amplifier is V output = G x (V1 - V2), which is digitized by an ADC and the output bits are sent to a processor. Anomalous values or variations in the product Vsaida = G x (V1 - V2) that exceed a predetermined threshold are indicative of a possible problem in a nozzle 40. Alternatively, problems are detected based on a variance of the values of Vsaida between each nozzle 40. Preliminary calibration is performed to account for manufacturing variations in the precision resistor, transistors, or nozzles 40 due to their location on the boom or fluid distribution tube (eg at the fluid source). If a temperature value is desired, the Icurrent current can also be monitored and measured using a sensing resistor in series with the precision resistor Ro so that the resistance of the thermistors R1 and R2 can be calculated from V1 = Icurrent x R1; V2 = Current x R2. If the transistors, or legs 104 and 106, differ due to manufacturing differences or due to layout differences, the current is substantially (e.g. 97 - 100%) the same across legs 104 and 106, but not necessarily identical. After obtaining the resistance values, the temperature is inferred from R1 or R2 or from a weighted average of R1 and R2.
[0061] Figure 16 illustrates an example of circuit 100 where differential signals from two capture points a single thermistor 50 are sampled in order to cancel ground jump or other signal failures and to improve signal-to-noise ratio. If the thermistor material is customized or accessible to the user, the derivation of two points in order to measure the voltage V1 and V2 at the two points is straightforward. Alternatively, if the thermistor 50 is an off-the-shelf device, there may not be an appropriate access point other than the end terminals. Then two off-shelf thermistors electrically connected in series can be used, but with their resistance values being different, such as R1 = 10 x R2. For better compatibility, the two thermistor devices must have the same packaging and parasitic elements so that they track both characteristics and performance. So the rest (differential amplifier, etc.) of circuit 100 in figure 16 is similar to that in Fig. 15. The two capture points are similar to R1 and R2 in Fig. 15. In Fig. 16, R1 includes all the resistance thermistor 50; R2 includes only part of the resistance of thermistor 50. For example, R1 = 10 x R2. And the resistances are obtained from the equations, V1 = Icurrent x R1; V2 = Current x R2. As the thermistors R1 and R2 are connected in series, the same current flows through each thermistor. Icurrent current can be measured using a sensing resistor on leg 102. After obtaining resistance values R1 and R2, temperatures T1 and T2 are inferred from R1 or R2, respectively, or from a weighted average of R1 and R2. Variance between nozzles 40 is detected by monitoring V1 and V2; or monitoring R1 and R2 or T1 and T2 if the Icurrent magnitude is measured.
[0062] As a generalization of some of the aforementioned situations such as when there is a large amount of fluid flowing beyond a thermistor 50 or temperature sensor or when the fluid is expected to remain in a sufficiently cold temperature range, the thermistor it does not have time to overheat even when a current passes through it because the thermistor is cooled by the surrounding fluid. In this scenario, some of the aforementioned modalities include predicting a constant or known amount of electrical current I through a thermistor, monitoring the voltage V across the thermistor, which then provides the resistance value R through Ohm's law, R = V / I. The R value then leads to a determination of the temperature T for the given material. To obtain a more accurate determination, it is often useful to measure both current I and voltage V simultaneously and then calculate the instantaneous value of R, and then calculate the temperature T from the value of R. When an abnormal temperature value T is observed, a clogging alert is generated. Alternatively, to determine anomalies among many nozzles, it is sometimes sufficient to monitor a variance between the different V values when the same amount of current is presented to each of the nozzle thermistors, without having to calculate the temperature value T. Through conservation current, the same amount of current can be supplied to each of the thermistors even over a long length of wiring.
[0063] Sometimes, such as when there is not much flow of fluid to be used in a bath at constant temperature (cold) or a thermistor material is such that it overheats quickly, some include passing a pulsed current (On / Off) ) through the thermistor. It is also possible to pulse a current through the thermistor even when there is a large amount of fluid or fluid flow. Pulsing the current (i.e., periodically interrupting it) keeps the thermistor cooler or in the operating range. Likewise, if there is an obstruction and the amount of stagnant fluid is small, pulsating the current through a thermistor tends to prevent the thermistor from being overheated. But if there is stagnant fluid, the thermistor still heats itself and the fluid stagnates, but it does not overheat to a point of destruction. That is, depending on the arbitrarily selected polarity, the thermistor heats up when current passes through it and it cools back when no current is flowing through it. Thus, the thermistor does not overheat and is damaged regardless of whether there is leaking fluid or stagnant fluid, but the thermistor will ideally register a different characteristic value for flow versus stagnant conditions. In some embodiments, the pulsed current I is prorated over time to determine a current level. Likewise, the voltage that produces (or reduces) the current is measured so that an average resistance is calculated (Average = Average / Average), and an average temperature is subsequently calculated from the average resistance Rm. As an alternative, instantaneous values are used in a calculation of Rmeana of way (Rmean = mean <Vinstant / Iinstant>). When an abnormal average temperature value is observed, a clogging alert is generated. Alternatively, to determine anomalies among many nozzles, it is sometimes sufficient to monitor a variance between the different values of Rmean, without having to calculate the temperature value Tmean.
[0064] In other embodiments, regardless of whether the current through the thermistor is pulsed or stable, the magnitude of the current is maintained at a fixed value or substantially (e.g. within 90 - 95%) fixed. Keeping the magnitude of the current, then the measured voltage (no pulsation mode) or the average of the measured voltage (pulsed mode), provides an indication of the temperature of the thermistor and its surrounding fluid. For example, now, calculated R = V measured / set in non-pulsed mode and (calculated average = mean <instant / ifixed>) in pulsed mode and the temperature is inferred from R and average. Then again monitoring a variance among the values obtained for the different nozzles provides an indication of anomalous behavior. Alternatively, a temperature magnitude is calculated using the Steinhart equations or temperature coefficient from the calculated values of R or Average. More accurate temperature estimates are obtained by performing calibrations or making an initial baseline measurement and storing the values or displacements or differential values between the different nozzles in memory and subsequently subtracting or taking into account the displacements in the calculations for the estimated final temperature.
[0065] Any combination of the aforementioned multiple methods of monitoring current across and voltage across thermistor 50 is also sometimes used to determine temperature variation and / or indications for an anomalous nozzle 40 (eg valves are not working properly , the nozzle is cracked). Predetermined criteria define the threshold for anomalous behavior. For example, when an individual reading is beyond a threshold value or a series of threshold values for the measured current, or when an individual reading is multiple standard deviations (eg 4 different from other readings. The predetermined criteria are based on initial calibration of the thermistors 50 and associated circuits for each nozzle Alternatively or together, a reference thermistor is placed in a section controller and its properties are measured The results from individual nozzle thermistors 50 are compared against the results of the reference thermistor .
[0066] In addition, there are other means of measuring current than one that uses a sensor resistor. A battery or similar voltage source can be used to supply a voltage to the thermistor 50. The current drawn by the battery is comparable to the current passing through the thermistor 50 (e.g. Fig. 12A). Battery units or voltage sources sometimes have a current indicator along with a voltage reading being supplied. The instantaneous values can be read by the section or central controller to determine the amount of current going to thermistor 50 from each nozzle 40. Another way to determine the current is to charge a capacitor for a particular period of time. When the voltage V exceeds a predetermined threshold value in that same period of time, this is indicative of the amount of current since Q = C x V, or dQ / dt = C x dV / dt, where Q is a charge and dQ / dt = current. A replica of Vpulso is also generated and supplied to a capacitor circuit C to detect a magnitude of the current going to the thermistor due to Vpulso.
[0067] Figure 17 illustrates another example of nozzle 200 where a fluid flow sensor or thermistor 50 is placed in an orifice 147 which is tubular. An optional strainer or membrane is located below the sensor or thermistor 50. The optional screen or membrane is mounted along the orifice 147 (e.g. as the thermistor 50). The limb is in contact with a pressure transducer to check the pressure or vibration along the membrane or strainer. Orifice 147 empties into a space between concentric cylindrical walls of the nozzle tube formed by 160A and 160B. Valves 162A and 162B either block or allow fluid flow. The valves are controlled by pulse width modulated signals. The fluid can flow to one of multiple outlets as described in the US patent application. No. 14 / 506.057, HYBRID FLOW NOZZLE AND CONTROL SYSTEM, which is incorporated by reference here.
[0068] Figure 18 illustrates an example of a multi-head nozzle 300 having an optional fluid flow sensor and strainer. A thermistor 50 is placed in a hole located behind the central cover. The manifold ring is not shown, but the fluid drains to 314. Only one of the five nozzle outlets 310 releases fluid, depending on the turret's rotation position. Near the fluid inlet, there is an optional strainer or membrane in the orifice (in addition to the valve) that captures unwanted particles. When the turret is rotated to such a position that none of the outlets 310 points directly down, and there is no fluid seeping out, the boom (on which the fluid pipe and nozzles are mounted) can be rotated so that the nozzle 300 it is sufficiently upside down to empty or tilt the particles trapped in the sieve out of the check valve 302. The tubular boom is rotatable due to the way in which the inner wing of the boom is mounted (eg stepper motor) for a central sprinkler vehicle frame.
[0069] The fluid flow sensors mentioned above are placed in individual nozzles 40. Sensors or similar thermistors 50 can also be located in the devices that supply the fluid. For example, figure 19 illustrates an example of a boom 30 with section 44 valves having a fluid flow sensor mounted inside the valves. As the orifices are larger in a boom valve 44, additional flow devices such as pressure sensors or motion detectors are also located there.
[0070] Figure 20 illustrates an example of a nozzle turned to a position where fluid flows to two outlets. Figure 21 illustrates an example of a nozzle rotated to a position where fluid does not flow to any nozzle outlet tips. This position in Fig. 21 helps an operator to clear an obstruction in the nozzle. As no fluid is released out of any nozzle tip, the remaining fluid and particles are discarded by turning the nozzles 40 upside down or the lance upside down or in a direction such that trapped particles can be expelled. For example, trapped particles are expelled from the check valve 302. The direction of fluid flow is reversed and released out of the check valve 302.
[0071] Figures 22 - 24 illustrate various sets of spray nozzles, lances, fluid distribution tubes and nozzles that contain the thermistor 50 and internal or external electronics to determine the presence of a fluid obstruction. If nozzle 40 has multiple outlets, if fluid is obstructed anywhere along the path to the operational outlet, the fluid will accumulate and become stagnant at the location of thermistor 50. Figure 22 illustrates an example of a suspension boom light fiber, behind which are nozzles 40 having fluid flow sensors. The wiring for electronic signal is routed in the void of the tubular boom. In one example, the fluid delivery tube is attached to and under the boom. These spears are either towed or the vehicle is a self-propelled motorized agricultural sprinkler. Figure 23 illustrates an example of a metal or fiber boom having trusses, among which are nozzles having flow sensors. The sensors communicate either wirelessly or over cables (e.g. CAN bus) with a processor circuit such as a central CPU or computer. Figure 24 illustrates an example of a lightweight metallic or composite fiber boom, under which nozzles are having fluid flow sensors. Wiring for the electronic signal is routed into the boom void. Each of the nozzles 40 mounted on the fluid distribution tube generates a reading from the thermistor 50. The readings are collected on a central controller circuit or computer as located adjacent to the section 44 valves or in the cab of the vehicle towing the sprinkler assembly. Light booms are suitable for having spray nozzles that include detection of obstruction or clogging because there is extra weight associated with additional electronics and detectors.
[0072] When anomalous behavior is signaled, a series of actions can happen automatically. For example, a visual or audio alert is generated by a central controller or a computer. The alerts indicate either a fixed threshold condition that is exceeded or a graduated level as to the severity of the obstructed condition or the magnitude of flow. In various modalities of the fluid flow monitoring system, there are also multiple possible responses and automated ways to resolve the obstructed condition. Alternatively, some or all of the correction modes are available for an operator to select individually.
[0073] An example of corrective action is that a clogged condition is removed by a diving method, using double valve vibration to loosen or displace debris in a 40 nozzle. Acute, rapid vibrations, both valves pushing and pulling simultaneously for movement maximum to push fluid and debris. Alternatively, the two valves are separated to create a vacuum in the orifice and then sudden pressure is applied when the two valves are pushed together. This shaking or diving motion is used to expel the particles trapped in a duct, or more often, at a tip of the nozzle 40. After the shaking motion, the fluid is discharged out (along with the particles) through a pressure valve. retention 302 or even through nozzle tips. In another mode, small rapid vibrations are created by the valves together with a movement of the membrane.
[0074] Another example of corrective action includes using the capacity of the sieve or membrane in the nozzle orifice to capture larger unwanted particles. The nozzles 40 are mounted on pivots that rotate and turn the nozzles 40 upside down to help dissipate debris. Or, the boom wings are raised, immersed, or rotated to reverse the direction of fluid flow. Another modality includes rotating the fluid delivery tube or the lance on its larger geometric axis, repeating the throttling action and / or vibration using the opposite valves to expel trapped particles out of a nozzle 40. Alternatively, if a nozzle tip is clogged, the nozzle turret rotates (automatically or manually, eg as described in US patent application 14 / 506,057) to another position for spraying fluid outside of another nozzle tip.
[0075] The thermal sensors mentioned above are generally superior to vibration sensors as detectors due to the cost and to avoid disturbing the spray pattern or to be limited to certain types of nozzles. Thermal sensors can be used with fluid-pulsed or continuous nozzles, but vibration sensors are for pulsed-type nozzles. Finally, the guidance and directions set out and illustrated in this invention should not be taken as limiting. Many of the guidelines set out in this invention and claims are with reference to the direction of travel of the equipment. However, the directions, e.g. "top", are merely illustrative and do not guide the modalities at all in space. In other words, a structure made with something about "top" is merely an arbitrary orientation in space that has no absolutes. Also, in real use, for example, boom equipment can be operated or positioned at an angle because attachments can move in many directions over a hill; and then "top" is pointing to the "side" So the directions set out in this application may be arbitrary designations.
[0076] In the present invention, the descriptions and exemplary modalities should not be seen as limiting. On the contrary, there are variations and modifications that can be made without departing from the scope of the attached claims.

权利要求:
Claims (18)
[0001]
1. System for monitoring fluids in nozzles, comprising: a spray nozzle (40) configured to release a fluid according to a desired flow rate; a thermistor (50) positioned on a fluid flow path within the spray nozzle in fluid communication with an inlet formed integrally as part of a circular spray nozzle assembly, wherein the thermistor is fully enclosed within a nozzle body sprinkler and is shaped and sized to conform to an inner surface of an orifice aligned coaxially with the inlet; characterized by the fact that it comprises an electronic feedback circuit (100) designed to try to maintain at least one of a current through the thermistor and a voltage across the thermistor; and a digital processor circuit (114) designed to generate an output signal to initiate corrective action to disable current flow through the thermistor if the actual flow rate falls below a predetermined threshold to allow the temperature of the thermistor to decrease ; wherein a measured value of at least one of the current and voltage other than a target value indicates a variation in the resistance of the thermistor; a degree of an obstructed condition or a type of fluid flow restriction is determined based on the measured change in resistance; a range of the measured value is correlated with an effective fluid flow; the range of the measured value is dynamically adjusted as the flow rate increases or decreases to maintain at least one current through the thermistor or the voltage across the thermistor by adjusting a baseline signal based on the calculated average of the current, a command Reset voltage is generated by the digital processor circuit to reactivate the current flow through the thermistor when the temperature reaches a lower temperature limit.
[0002]
2. System according to claim 1, characterized by the fact that the electronic feedback circuit is electronically connected to conductors of the thermistor (50), and at least part of the electronic feedback circuit (100) is outside the flow path, but still inside the spray nozzle.
[0003]
3. System according to claim 1, characterized by the fact that the electronic feedback circuit (100) is in communication with a computer having a screen that displays a spray nozzle alert, as determined by a deviation from the measured value in addition to a predefined threshold.
[0004]
4. System according to claim 1, characterized by the fact that the electronic feedback circuit (100) includes a pulse width modulated circuit, and in which a pulse width is adjusted to maintain the current through the thermistor.
[0005]
5. System according to claim 1, characterized by the fact that the thermistor (50) comprises a resistor.
[0006]
6. System according to claim 5, characterized by the fact that a sensor resistor is in series with the thermistor (50) and the voltage across the sensor resistor indicates the current through the thermistor.
[0007]
7. System according to claim 5, characterized by the fact that the current or voltage beyond a threshold value is signaled as a stagnant state of the spray nozzle and an alert is issued.
[0008]
8. System according to claim 5, characterized by the fact that the spray nozzle includes multiple thermistor, each of which is associated with a fluid outlet from the spray nozzle.
[0009]
System according to claim 1, characterized in that a plurality of spray nozzles is mounted on a spray lance for an agricultural application, and each of the plurality includes a thermistor to provide flow values; and a deviation from the flow values indicates anomalous fluid flow in at least one of the plurality of spray nozzles associated with the deviation.
[0010]
10. Agricultural sprinkler system, comprising: a spray lance (30) mounted on a motor vehicle (20); a fluid distribution tube (42) mounted on the spray boom (40); and spray nozzles (40) mounted along the fluid delivery tube to receive a fluid; each of the spray nozzles includes a thermal sensor system having: a thermal sensor (50) positioned on a fluid flow path within each of the spray nozzles in fluid communication with an inlet formed integrally as part of a circular assembly of the sprinkler nozzle, wherein the thermal sensor (50) is completely enclosed within a sprinkler nozzle body and is shaped and sized to conform to an inner surface of an orifice aligned coaxially with the inlet; characterized by the fact that it also comprises: an electronic circuit that tries to maintain at least one of a current through the thermal sensor and a voltage along the thermal sensor; a digital processor circuit (114) designed to generate an output signal to initiate corrective action to disable current flow through the thermal material if the actual flow rate falls below a predetermined threshold to allow the temperature of the thermal material decrease; wherein a measured value of at least one of the current and voltage other than the target value indicates a change in resistance of the thermal sensor; a degree of an obstructed condition or a type of fluid flow restriction is determined based on the measured change in resistance; the measured value correlates with a flow rate of the fluid in each of the spray nozzles; a range of the measured value is dynamically adjusted as the flow rate increases or decreases to maintain at least one of the current through the thermal sensor or the voltage through the thermal sensor by adjusting a baseline signal based on the calculated average of the current, and a reset command is generated by the digital processor circuit to reactivate the current flow through the thermal sensor when the temperature reaches a lower temperature limit.
[0011]
11. Agricultural sprinkler system according to claim 10, characterized by the fact that the electronic circuit (100) is electronically connected to conductors of the thermal sensor, and at least part of the electronic circuit is outside the fluid flow path, but still inside each spray nozzle; and where the electronic circuit includes a pulse width modulated circuit, and where a pulse width is adjusted to maintain current through the thermal sensor
[0012]
12. Agricultural sprinkler system according to claim 10, characterized by the fact that the value measured from each of the sprinkler nozzles is compared with a maximum and a minimum threshold value.
[0013]
13. Agricultural sprinkler system according to claim 10, characterized by the fact that initiating corrective action also comprises initiating corrective action to expel a stagnant state, the current or voltage beyond a threshold value is signaled as the stagnant state of the spray nozzle; and where under the stagnant state, an alert is issued.
[0014]
14. Agricultural sprinkler system according to claim 13, characterized by the fact that the corrective action includes at least varying a sprinkler boom position, varying a sprinkler nozzle position, or immersing a valve into the sprinkler nozzle associated with the stagnant state.
[0015]
15. Agricultural sprinkler system according to claim 10, characterized by the fact that the thermal sensor (50) comprises at least one of a thermistor or a resistor.
[0016]
16. Agricultural sprinkler system according to claim 13, characterized by the fact that each of the sprinkler nozzles includes a first flow valve and a second flow valve; the thermal sensor (50) is located between the first flow valve and a first spray outlet nozzle; and a second thermal sensor (50) is located between the second flow valve and a second outlet of the spray nozzle.
[0017]
17. Sprinkler system according to claim 10, characterized by the fact that the sprinkler lance comprises composite fiber material.
[0018]
18. Agricultural sprinkler system according to claim 10, characterized by the fact that the fluid distribution tube comprises a fluid section valve; and the fluid section valve also includes the thermal sensor (50) to detect a section flow through the section valve.

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同族专利:

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公开号 | 公开日

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US20160178422A1|2016-06-23|

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US10444048B2|2019-10-15|

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AU2015268661A1|2016-07-07|

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BR102015031713A2|2016-10-11|

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EP3035007A1|2016-06-22|

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AU2015268661B2|2019-07-11|

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法律状态:
2016-10-11| B03A| Publication of a patent application or of a certificate of addition of invention [chapter 3.1 patent gazette]|

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2018-12-26| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|

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2019-09-10| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|

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2020-10-20| B06A| Notification to applicant to reply to the report for non-patentability or inadequacy of the application [chapter 6.1 patent gazette]|

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2021-03-23| B09A| Decision: intention to grant|

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2021-04-13| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 17/12/2015, OBSERVADAS AS CONDICOES LEGAIS. |

优先权:

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US201462094538P| true| 2014-12-19|2014-12-19|

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US62/094,538|2014-12-19|

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US14/927,777|2015-10-30|

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US14/927,777|US10444048B2|2014-12-19|2015-10-30|Fluid flow monitoring system|

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