• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
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    • 专利摘要:
    A method for controlling a torque torque converter (TC / LUC) includes supplying a TC / LUC control signal (Pset) to the TC / LUC to set the TC / LUC (20) in a desired operational mode . The method comprises a calibration procedure with the following steps: - with a blocked feedback control effecting a gradual disconnection of the TC / LUC starting from an engagement state preceding the calibration procedure; - after detecting that a monitored slip value of the TC / LUC exceeds a predetermined threshold value, enabling the feedback driver to determine a representative value of a feedback control signal that in combination with an open loop reference signal results in an operation of the TC / LUC ( 20) with a reduced slip value, - switching off feedback control and changing the open loop reference signal with an adjustment value based on the representative value.
    公开号:BE1025869A9
    申请号:E201706036
    申请日:2017-12-29
    公开日:2019-10-22
    发明作者:Thierry Matheus Hendrikus Kornelis Laheij；Kevin Strandby Rice
    申请人:Punch Powertrain Nv；
    IPC主号:
    专利说明:

    Control device for a power train and method for controlling a power train as well as a power train comprising the control device.
    BACKGROUND
    The present invention relates to a control device for a power train.
    The present invention further relates to a method for controlling a power train.
    The present invention further relates to a power train including the control device.
    A powertrain in a continuously variable transmission typically includes a torque torque converter / lock clutch (TC / LUC), a forward-neutral reverse clutch (DNR) and a variator. The variator is typically provided as a transmission belt that mechanically couples two pulleys. In a normal drive mode, all elements of the drive line preferably work slip-free because slip would entail energy losses and thus lead to an unfavorable fuel consumption. Slipping of the variator must in particular be avoided since this leads to wear of the transmission belt and / or the pulleys. This can be achieved through high clamping levels. On the other hand, clamping levels, in particular a clamping level of the transmission belt, should not be set too high, as this would mean that an unnecessarily high control current is supplied by the charging system to maintain this high clamping level, which is also unfavorable for fuel consumption. Moreover, increasing the clamping level above a level required for slip-free operation of the variator generally leads to an increase in transmission losses of the variator and further to increased wear of the variator due to increased friction. In addition, it must be taken into account that the driving conditions can suddenly
    BE2017 / 6036, for example due to road damage or rapid vehicle braking. To prevent the variator from slipping in such situations, a LUC torque torque capacity must be set to a value that is lower than a torque torque capacity of the variator. Thus, in the event that an unexpectedly high torque is to be transmitted, the TC / LUC acts as a fuse which absorbs the unexpected torque by slipping, thereby avoiding slipping of the variator. The LUC, usually designed as a fluid coupling, can operate in a continuous slip mode without damage.
    US2003150683 discloses a control method for a power train comprising a continuously variable transmission and a coupling arranged in series therewith. The control method comprises a procedure in which an engagement pressure of the clutch is first reduced until a slip occurs, and then increased after detection of the slip to again achieve a secured operational mode, wherein a required engagement pressure is calculated by the engagement pressure where the locked operational mode was achieved, plus an overvalue such that an overvalue of the torque transmitted by the clutch is set lower than that of the continuously variable transmission. The control method causes variations in the clutch settings that can be perceived by the driver or passengers in the car and thereby reduce driving comfort.
    RESUME
    It is a first object to provide a control device for a power train, wherein the risk of discomfort due to variations in the clutch settings is reduced.
    BE2017 / 6036
    It is a second object to provide a control method adapted to control a power train with a reduced risk of discomfort due to variations in clutch settings.
    It is a third goal to provide a powertrain including the improved control device.
    In accordance with said first target, a control device is provided according to claim 1.
    The control device according to the claims comprises a TC / LUC control unit for providing a TC / LUC control signal for controlling an engagement state of the torque clutch of the torque torque converter. The TC / LUC control unit comprises an open-loop control section and a closed-loop control section. For example, the TC / LUC control signal can be provided to a controller that generates electrical control signals for a hydraulic control unit that is provided to operate the TC / LUC. Alternatively, the TC / LUC can be controlled without an intermediate hydraulic control unit, for example, by one or more electromagnetic actuators that are directly coupled to a TC / LUC element. The control device includes a calibration facility to calibrate the TC / LUC control unit. It can thus be achieved that the operation of the TC / LUC control is adapted to behavioral changes over time, for example as a result of wear and tear variations. The open loop control section is configured to determine a nominal control signal value, which is an originally estimated value of the control signal that is expected to reach a predetermined engagement state of the TC / LUC.
    The TC / LUC control unit further comprises a closed-loop control section. This control section is adapted to adjust the TC / LUC control signal to a value that minimizes a deviation
    BE2017 / 6036 between an actual engagement state and the predetermined engagement state when the closed-loop control section is turned on. Such a deviation can for example be detectable as a slip value, e.g. a ratio between an input rotation speed and an output rotation speed, or a difference between an input rotation speed and an output rotation speed.
    The control device comprises at least one calibration mode that includes a first, a second and a third calibration step.
    In the first calibration step, the feedback control section is disabled and the open loop control section gradually adjusts the value of the TC / LUC control signal from an initial control signal value to a stop control signal value. The initial TC / LUC control signal value is the value of the TC / LUC control signal immediately before entering the calibration mode. Thus, before the calibration mode enters, the feedback control section is turned off, the initial TC / LUC control signal value is equal to the immediately preceding value of the control signal output from the open loop. The latter may include a predetermined component that does not change over time and a calibration component that is determined in the calibration mode. Alternatively, the open-loop control signal value can be provided as a single calibrable signal. The value of the stop control signal is the value of the TC / LUC control signal where it is detected that the TC / LUC assumes a slipping operational mode, e.g., the value for which a slip of the TC / LUC becomes detectable, e.g. a value for which it is detected that the outgoing rotation speed starts to differ from the entered rotation speed. Alternatively, the predetermined slip value can be a slip value that defines a predetermined ratio between the output rotation speed and the input rotation speed.
    After detecting the slipping operational mode, a second calibration step follows. The feedback control section becomes therein
    BE2017 / 6036 enabled to adjust the value of the TC / LUC control signal from the stop control signal value to an intermediate control signal value for which it is detected that the TC / LUC reaches the predetermined engagement state. This predetermined engagement state is typically an operational state of the TC / LUC at its slip limit, i.e., with a minimal degree of engagement required to maintain slip-free operation at a current value of a torque torque transmitted by the TC / LUC. Alternatively, the predetermined engagement state may be another engagement state that is taken as a reference, e.g. a state in which the TC / LUC has a certain slip value at a current value of a transmitted torque. Preferably, however, the predetermined engagement state to be achieved with the feedback control section is the operational state of the TC / LUC at its slip limit, since this makes it possible to minimize the slip of the TC / LUC during the calibration procedure.
    Then, a third calibration step follows in which the feedback control section is again disabled and the calibration value is set to a value based on a difference between the intermediate control signal value and the nominal control signal value.
    In the control device according to the claims, the activation of the feedback control section in the second calibration step achieves a smooth but rapid transition between the first and the third calibration step. This contributes to driving comfort.
    This advantage is also achieved with the method of claim
    6.
    Furthermore, an improved drive line according to claim 14 is provided. The improved drive line comprising a continuously variable transmission system comprising a torque torque converter / lock coupling
    BE2017 / 6036 (TC / LUC), a forward-neutral-reverse coupling (DNR) and a variator, further comprises the control device defined in the claims.
    BRIEF DESCRIPTION OF THE DRAWINGS
    These and other aspects are described in more detail with reference to the drawings. In there:
    FIG. 1 schematically shows a drive line in a vehicle;
    FIG. 2 shows in more detail a part of a control device for the power train;
    FIG. 3 illustrates various signals and status indicators during operation;
    FIG. 4A-4C illustrate the control unit in various operational states;
    FIG. 5 illustrates a control method;
    DETAILED DESCRIPTION OF EXEMPLARY EXAMPLES
    FIG. 1 schematically shows a power train in a vehicle for transferring power from a power source 10, such as a combustion engine or an electric motor, to wheels 70 of the vehicle. The drive line as shown in FIG. 1 comprises a torque torque converter / locking coupling (TC / LUC) 20, a forward-neutral-reverse coupling (DNR), a variator 40, a fixed transmission 50 and a differential 60. The TC / LUC 20 couples an output shaft of the power source 10 on the DNR 30, with a controllable slip ratio and torque-torque ratio correlated therewith, ie the ratio between the output torque torque and the torque torque received at its input from the power source 10. The DNR coupling 30 is provided to couple the TC / LUC 20 to the variator 40. The DNR coupling 30 can be controlled to adopt one of the following modes, a drive mode D corresponding to the forward
    BE2017 / 6036 direction of the vehicle, a reverse mode R, in which the vehicle is driven in reverse and a neutral mode in which it keeps the variator 40 disconnected from the TC / LUC 20. The variator 40 transfers the energy supplied from the power source 10, via the TC / LUC and the DNR coupling 30 via the fixed transmission 50 and the differential 60 to the wheels 70, with a transmission ratio that can be selected from a continuous range.
    In the illustrated embodiment, a setting or operating mode of the TC / LUC 20, the DNR 30 and the variator 40 is determined by hydraulic signals, i.e., a pressure of a hydraulic fluid. The hydraulic signals are supplied by a hydraulic control unit (HCU) 80, which is supplied with a supply current P80 by a pump 85. In the embodiment shown, the state of the TC / LUC 20 is controlled by hydraulic pressure P20, the state of the DNR coupling 30 is controlled by hydraulic pressure P32 and the condition of the variator is adjusted by hydraulic pressures P41 and P42. To this end, the hydraulic control unit 80 is in turn controlled by a transmission control unit (TCU) 100. Alternatively, the state of the different drive train elements can be controlled by electrical signals, for example with the aid of electromagnetic control elements. The TCU 100 is further coupled, e.g. via a bus, here a CAN bus 95, to a motor control unit 90. The TCU is further configured to receive input signals from different inputs, such as a turbine speed signal (the output rotational speed of the TC / LUC), a primary pulley rotational speed, corresponding to the DNR output speed, a secondary pulley rotation speed at the output of the variator 40, a secondary pulley pressure and an oil reservoir temperature. Other input signals, for example from an accelerator pedal, a brake pedal (not shown) and sensor elements, e.g. speed sensors, temperature sensors, torque torque sensors and the like
    BE2017 / 6036 (not shown) can be received and monitored by the motor control unit 90 and transmitted to the TCU 100 via the CAN bus 95.
    FIG. 2 shows in more detail a TC / LUC-controller 20 for controlling a state of the TC / LUC 20. In this drawing illustrates component 115, the elements to which a drive signal P se t translate into a pressure P20 which is to be provided to the TC / LUC 20 to achieve a desired setting thereof. The TC / LUC control C20 includes an open loop control section OLC and closed loop control section or feedback control section CLC. Its operation is controlled by a main controller 110.
    Depending on a general operational mode, the main controller 110 can configure the TC / LUC control unit C20 in various ways. The general operational mode can be determined by the operational state of the vehicle, e.g. start-up, standstill, acceleration from standstill, stationary driving, braking, and can be further determined by a power setting, e.g. selected in a range from an energy saving mode to a high power mode.
    In the embodiment shown, the main controller 110 determines the operation of the TC / LUC control unit C20. The main controller 110 typically also controls other parts of the transmission system, such as the DNR 30 and the variator 40, as schematically indicated by the block arrows S10, S30, S40 that represent issued control signals and received state signals. The main controller 110, in turn, interacts with the drive 5, for example, receiving input signals from the driver, such as an accelerator pedal pressure, and a brake signal pressure, a R / N / D transmission mode selection, and the like. The main controller can also send status signals to the driver via a control panel. The main controller 110 may also request certain functionality of the ECU 90. In exceptional cases, e.g. upon detection of a
    BE2017 / 6036 error such as a defect in the transmission, the main steering can become dominant and, for example, force the vehicle to only drive at low speed (to get to the side of the road, etc.)
    An embodiment of the TC / LUC control unit C20 is now described in more detail. As mentioned above, it includes an open loop control section OLC and a closed loop control section, also referred to as feedback control section CLC. In the embodiment shown, the open-loop control section has a nominal control signal generator 120 to generate the nominal control signal Pf which indicates a nominal control value estimated to reach a predetermined engagement state. The predetermined engagement state is a state of the TC / LUC, which would enable it to be to a torque having a by the main controller 110 specified reference value M re f to be transmitted at a likewise by main control 110 specified slip value No e, f, Generally the predetermined engagement state is the state in which the TC / LUC operates at its slip limit. In reality, the actual behavior of the TC / LUC will differ from these reference characteristics, due to wear and tear of the TC / LUC and due to temperature variations. A calibration signal generator is provided which is to generate a calibration signal P ca i that indicates a calibration value. The open-loop control unit OLC is configured to provide an open-loop control signal P o ic with a value based on the nominal control value and on the calibration value to control the TC / LUC in open-loop mode. In the embodiment shown, this is achieved by adding these values to adder 122. The TC / LUC control unit further comprises a closed-loop control section CLC which is arranged to provide a correction signal P c indicating a correction where the open-loop control signal P o in this case in order to correct for deviations between the actual
    BE2017 / 6036 engagement state and the predetermined engagement state in an activated state of the closed-loop control section.
    In the illustrated embodiment, the closed-loop control section CLC a comparator 111 to output an error signal e which is indicative of a difference between a slip value n s, re f as specified by the main controller 110 and a measured slip value ns, as determined by a slip value sensor 116. The slip value sensor may, for example, determine the slip value ns as the difference nt, ie the difference between the rotational speed ne at the input of the TC / LUC and the rotational speed nt at the output of the LUC. An adaptation controller, such as a PI-regulator 112, is provided which emits the correction signal P c, which can be added to the open-loop control signal P o in this case to the control signal P se t to obtain. The control signal P se t may be converted into a control current which, in turn, the hydraulic control unit HCU 80 controls, which, in response, the required hydraulic pressure signal P20 for the TC / LUC generates 20. In FIG. 2, the combined functionality of converting to a control stream and generating the pressure signal P20 is shown schematically by module 115.
    The main controller 110 is configured to selectively enable the feedback control loop as schematically indicated by the switching element 113, which is controlled by switching signal S113. FIG. 2 schematically illustrates different calculation steps as a separate element. For example, it has been shown that the adders 122, 123, and 114 combine different control signals. However, it is not necessary for the control unit to be implemented in this way. Different functions in the control unit can for instance be performed in different ways.
    It is important that the open-loop control section OLC is able to properly hold the TC / LUC in a locked mode. That is, a skidding of the TC / LUC must occur during normal driving conditions
    BE2017 / 6036 are avoided, while the TC / LUC is able to serve as a fuse in the transmission system in order to prevent slippage occurring in the variator with an unexpectedly high torque. However, the behavior of the TC / LUC varies over time due to wear and temperature variations.
    To maintain a reliable open-loop control, the control device can be operated in a calibration mode described in more detail with reference to FIG. 3.
    FIG. 3A-3C illustrate various signals and status indicators during the operation of the controller. In FIG. 3A shows the solid line M21 an actual torque Mi uc (torque [Nm]), which without slip by the TC / LUC 20 can be transferred and the long-dotted line M22 a nominal value M re f of the torque that the Lucu without slip in the current circumstances, taking into account a safety margin value. The shorter dotted line M23, slightly above the longer dotted line, indicates a value that corresponds to a desired effect around the slip limit.
    As is clear from the example in FIG. 3, in particular as shown in FIG. 3A, at the time t 0, the actual torque torque capacity Mi uc , indicated by curve M21, is considerably higher than the desired level given the current conditions. To prevent a risk of the variator slipping, this also means that the transmission belt of the variator must be kept at an unnecessarily high voltage. In this situation, if an unnecessarily high driving current is supplied by the charging system to maintain this high clamping level, this would be at the expense of an additional fuel consumption. The variator can also suffer from increased wear and cause more power loss than strictly necessary.
    In FIG. 3B shows the curve a P21 value of a TC / LUCstuursignaal P se t as a function of time. In this case, the value
    BE2017 / 6036 as a pressure value (pressure [bar]) that is applied to a hydraulically controlled TC / LUC. In this example, the degree of coupling generally increases with an increasing value of the control signal. In other embodiments, the extent of engagement may generally decrease with an increasing value of the control signal. Alternatively, the value of the TC / LUC control signal can be expressed as a voltage or a current, for example, the value of the control voltage or control current used to control a pressure value of a hydraulic pressure for controlling a hydraulically controllable TC / LUC or a control voltage or control current for controlling an electromagnetically operated TC / LUC.
    The broken line P22 which extends over the full width in FIG. 3B extends is a value of the TC / LUC-control signal which is initially expected that it reaches an engagement state of the TC / LUC, in which the latter is able, to the nominal value (M re f) during operation in its slip threshold of the to transmit transmitted torque. The shorter dotted line P23, slightly above the longer dashed line, indicates the value of the TC / LUC control signal P se t which is required to actually achieve that the TC / LUC that torsion torque can transmit while working at his slip threshold.
    FIG. 3C shows indicators for a state of the TC / LUC. The straight fine S24 (SW state) indicates the state of the TC / LUC 20 at a higher control level. In particular, it indicates that in the time interval represented by this graph, a locked mode of the TC / LUC is desired at the higher control level. The piece-by-line linear curve S25 shows schematically the current physical state of the TC / LUC 20.
    An example of a control method for controlling a TC / LUC is now described with reference to FIG. 3A-3C, introduced above. As can be seen in FIG. 3A-3C, during a first time interval ranging from to to ti, a control signal P se t
    BE2017 / 6036 is applied which is the sum of a first feed forward Pf component expected of which is that it is required in order to achieve a nominal voltage that is required during operation on the shpgrens a torque M re f to be transmitted, and a calibration component P ca i which is provided as a second feed forward component to enable the TC / LUC to transmit a torque up to a predetermined threshold level Mi uc without slip. The control unit in this operational state is shown in FIG. 4A.
    As indicated above, under the conditions shown in this example, the torque torque capacity Mi uc is set too high. Starting from this operational state, where the TC / LUC is secured, it is possible to start a calibration procedure. Other requirements may be verified to determine whether or not a calibration procedure is initiated, such as whether or not a predetermined period of time has elapsed since an earlier performance of the calibration procedure. If a lapse of a predetermined period of time is one of the conditions, an initiation of the calibration procedure can take place before the predetermined period of time in the event of a failure, such as high fuel consumption or unexpected occurrence of discontinuities in the torque torque transfer or slip value.
    At the time t 1 and as shown in FIG. 4B, the calibration procedure is started. In this first phase of the calibration procedure, a modification component P mo d is added to the nominal control value. In FIG. 2, this is shown schematically as the contribution P mo d provided by the ramp signal generator 124 in the open-loop control section OLC. Starting from the original value, equal to the value of the calibration signal P ca i, the value of the modification component P mo d is changed gradually, as indicated by slope a in FIG. 3, to cause a gradual disconnection of the TC / LUC. It is assumed here that the degree of engagement of
    BE2017 / 6036 TC / LUC is positively correlated with the signal P se t. Alternatively, the correlation may be negative, in which case the modification component must have a positive inclination. At time t2, the control signal value P se t is reduced to a value at which the TC / LUC operating at its slip threshold. At a further point in time te, with Ï 3-Ï 2 = f, the control signal has reached a stop value P s top for which the slip is actually detected.
    After this detection at the time, a second calibration step is started, wherein the feedback control mode is switched on again as shown in FIG. 4C. In FIG. 2, this would imply that the main control 110 with control signal S113 causes a closing of the switching element 113. The feedback control section CLC gradually adjusts the value of the P control signal se t of the value Pf + P mo d (te) to the value that is needed to the TC / LUC in its predetermined engagement state to be set, typically an engagement state in which the TC / LUC the minimum degree of engagement required to maintain slip-free operation at an instantaneous value of a torque torque transmitted by the TC / LUC. Then, the control signal P se t stabilizes when the feedback control signal Pc an intermediate value P c, iock has been reached. The feedback component can be considered sufficiently stabilized if variations therein are smaller than a predetermined threshold value, for example based on an estimated noise level, for example a slip value corresponding to slip-free operation or with a predetermined minimum amount of slip. The intermediate value, for example, may be an average or a median value of the control signal P se t during a time interval wherein the feedback component is stabilized. Alternatively, the feedback component can be considered to be sufficiently stabilized after a predetermined time interval has elapsed. This predetermined time interval can be related to a time constant of the feedback loop, for example a time interval with a duration of 2 or 3
    BE2017 / 6036 times that time constant. Although the feedback component may still exhibit variations that exceed the noise level, the intermediate value may be calculated by extrapolating the feedback control signal Pc based on the value at and the value of the feedback component at a predetermined time interval after t4. As can be seen in the time interval t3-t4, the feedback control quickly restores the TC / LUC 20 to a slip-free operational mode, while ensuring a smooth transition from low slip to slip-free operation near the end of the second step.
    Then a third calibration step starts in which the feedback control is switched off again, as shown in FIG. 4A, and wherein an updated calibration value for the calibration signal P ca i is set. The calibration value worked is based on the difference between the intermediate value P c , iock and the nominal control value Pf. In one embodiment, the calibration value worked may be equal to this difference. In another embodiment, the updated calibration value is set to the sum of this difference and an additional value b as illustrated in FIG. 3B. The difference P c, iock - Pf can be calculated from the difference of the value of the control signal P se t at time t4, or may modify the correction signal Pc at the time t4, that is necessary to the Pf signal to control the predetermined achieve the value of the engagement state. As noted above, in the illustrated embodiment, the feedback control section includes a PI controller 112, ie, the feedback control section includes an integral action control component. In one embodiment, can be used, the output of the integral-action controller component for the determination of the incremental signal is P c, iock. This has the advantage that this signal is already free of noise due to the integrating effect of this component.
    This aspect is illustrated schematically by update element 125, which registers the intermediate value of the feedback component Pc with which the predetermined engagement state was achieved. Based on this
    BE2017 / 6036 signal, the update element 125 updates the calibration signal P ca i to be provided by element 121.
    As can best be seen in FIG. 3B, at the time ts, in step 3 of the calibration procedure, the updated calibration value is based on the intermediate value in that a further component designated b is added as part of the feed forward signal. A safety margin is provided in this way. This achieves that normal torsional torque variations due to small variations in the level of the road surface do not immediately cause the TC / LUC to slip. As is further shown in the middle graph, in a first phase of the third calibration step from the point t4 to t4a the further component b is gradually increased from 0 to its final value, according to a slope indicated as c. At the time t4a a stationary phase is reached in which the calibration signal is kept at the excessive modification value. This prevents discontinuities in the transmission behavior of the TC / LUC.
    At the time ts, a new calibration cycle is initiated, with phases of the calibration procedure at the times ts to tg corresponding to those at the times t1 to t4, respectively.
    It is noted that the calibration procedure is in principle carried out in a locked mode of the TC / LUC. Although the TC / LUC is temporarily put into a slip state, this is done in a controlled manner. Accordingly, generates the nominal control signal generator 120 during the calibration procedure, the nominal control signal Pf its output which is transmitted freely the specified torque M re f slip, although there is a minimal amount of slippage occurs during the calibration procedure. In other operational states, the nominal control signal generator 120 can calculate the nominal control signal Pf by also taking into account a specified slip value n s , ref other than 0.
    BE2017 / 6036
    It is noted that the graphs are not drawn to scale. The time interval f can for instance be considerably smaller than the time interval suggested by the drawing. The length f of the time interval for detecting slip can, for example, be of the order of a few tens of ms, e.g. 20 ms, because it is mainly determined by valve hysteresis and the detection time required for slip detection. The timer for starting a new calibration cycle can, for example, be set to a value g in the order of a few seconds to tens of seconds. The timer is provided to release a time frame in which the TC / LUC is released to set a new operating point specified by external drive control signals.
    FIG. 5 schematically shows a calibration procedure in a control method for controlling a TC / LUC 20 which is included in series with a variator 40 in a continuously variable transmission system. The control method provides a TC / LUC control signal P se t to the TC / LUC 20 in a desired operational mode to be set. The control signal is obtained by closed-loop control, open-loop control or by a combination of open-loop control and closed-loop control.
    In step S0, it is determined whether the calibration procedure is to be initiated. For example, it can be determined whether the TC / LUC is currently operating in a locked mode. If this is not the case, an intermediate step can be performed in which the TC / LUC is controlled to assume a guaranteed operational mode. Furthermore, it can be determined whether the transmission system operates at a relatively low clamp level, such as a level designated as MIN or ECO. If the transmission system operates at a relatively high clamping level, an intermediate step can be performed in which the clamping level is reduced to a relatively low clamping level. It can also be verified whether a predetermined time interval has elapsed since completion of a previous calibration procedure. In some cases it is possible
    BE2017 / 6036 these requirements are absent or are ignored in the event that a system defect is detected.
    In the event that it is decided in step S0 to initiate a calibration procedure, a first calibration phase starts in step S1A, wherein an open-loop based control signal is provided to the TC / LUC causing a gradual disconnection of the TC / LUC from a coupled state that precedes the calibration procedure, while a slip value (ns) is monitored during the gradual disconnection. This process of gradual decoupling continues until it is detected in step S1B that slip occurs, i.e. a value of ns deviating from 0. In practice, this may imply a slip value that exceeds the detection accuracy, i.e., the accuracy with which the slip value is measured.
    In step S2A, the second calibration step begins, enabling a feedback driver to determine a representative value of a feedback driver signal which, in combination with the open-loop driver signal, results in an operation of the TC / LUC with a reduced slip value. This is typically an engagement state where the TC / LUC works slip-free. If it is determined in step S2B that this state is reached (Selection No), the control flow proceeds to the third calibration step.
    In the third calibration step in step S3, the feedback control is disabled. Instead, the feed forward control signal is modified with a modification value based on the representative value determined in the second calibration step. The modification value may gradually increase from an initial modification value equal to the representative value to an excessive modification value, which is slightly higher than the initial modification value, to prevent the TC / LUC from slipping due to normal variations in a torque torque value.
    BE2017 / 6036
    In step S4, a timer is activated to postpone a subsequent calibration procedure until after a predetermined period of time. Optionally, a timer can be absent and the calibration procedure can be started after detection of a start condition, indicative of incorrect transmission system calibration. Also, an operation of the timer can be ignored upon detection of such a state.
    It is noted that the calibration procedure as described herein is particularly suitable for use in a low power operational mode where the TC / LUC operates relatively close to its slip limit.
    In low power operation modes, low terminal levels are set for the TC / LUC and the variator. This also means that the torque torque capacity of the variator should not be set significantly higher than that of the TC / LUC, but just sufficiently higher for the TC / LUC to function as a torque torque fuse. In such operational modes, small deviations in the actual state of these transmission components, for example due to production variations, wear and temperature dependencies, can easily become dominant, so that the TC / LUC has the highest torsional torque capacity instead of the variator. Accordingly, the calibration procedure is particularly relevant for low power operation modes. If the transmission system is operating in a higher power mode, a transition phase can be provided in which the degree of engagement of the TC / LUC is gradually reduced from the relatively high degree in the higher power mode to the relatively modest degree in the low power mode. This is schematically illustrated in FIG. 6. In higher power operating modes, a larger margin can be applied between the torque torque capacity of the variator and the torque torque capacity of the TC / LUC, so that the above-mentioned uncertainties can be put into practice
    BE2017 / 6036 ignored. A manual calibration is sufficient for these operational modes.
    It is noted that exemplary embodiments may be implemented in digital electronic circuits, or in computer hardware, firmware, software, or combinations thereof. While, for example, specific functions can be performed by respective specific functional elements, it is also possible to perform different functions by the same element at different times. Exemplary embodiments may be implemented using a computer program product, e.g., a computer program stored in an information carrier, e.g., in a machine-readable medium for execution by or for controlling the operation of data processing equipment, e.g., a programmable processor, a computer or multiple computers. In an exemplary embodiment, the machine-readable medium may be a non-volatile machine-readable storage medium.
    权利要求:
    Claims (14)
    [1]
    CONCLUSIONS
    A power train control device (80, 90, 100) with a variator (40) and a torque torque converter (TC / LUC) (20) arranged in series with the continuously variable transmission, the control device being a TC / LUCbesturingseenheid (C20) for providing a TC / LUC-control signal (P se t) for controlling an engagement state of the locking coupling of the torque converter, and comprising a calibration facility for calibration of the TC / LUCbesturingseenheid, wherein the TC / LUC-control unit includes an open-loop control section (OLC) for determining a nominal control signal value (Pf) of the TC / LUC-control signal (P se t), estimated to reach a predetermined engagement state, and wherein the TC / LUCbesturingseenheid further comprises a closed-loop control section (CLC) through which issues the TC / LUCbesturingseenheid the TC / LUC-control signal (P se t) with a value for deviations between an actual engagement state e n minimizing the predetermined engagement state to an activated state of the closed loop control section, wherein the control device has at least one calibration mode comprising the following calibration steps:
    a first calibration step in which the feedback control section (CLC) is disabled and wherein the open-loop control section gradually changes the value of the TC / LUC control signal from an initial open-loop control signal value, being the value of the TC / LUC control signal (P se t ) immediately prior to entering the calibration mode until the TC / LUC control signal assumes a stop value (T s t on ) for which it is detected that the TC / LUC assumes a slipping operational mode, a second calibration step following said detection, the feedback control section (CLC) in able to value
    BE2017 / 6036 of the TC / LUC control signal (P se t) from said stop value (P stop) to an intermediate value (P c , k> c k) where the TC / LUC reaches the predetermined engagement state, a third calibration step that commences after detection of the predetermined engagement state, with the feedback control section turned off, and wherein the open loop control section is calibrated in accordance with a difference between the intermediate value (P c , k> ck) and the nominal control signal value (Pf).
    [2]
    The control device of claim 1, wherein the predetermined engagement state is a state of the TC / LUC with a minimum degree of engagement required to maintain slip-free operation at a current value of a torque torque transmitted by the TC / LUC.
    [3]
    3. The control apparatus according to claim 1 or 2, wherein the calibration facility in the third calibration step, the open-loop control section calibrates in order to provide a TC / LUC-control signal (P se t) that the TC / LUC holds in a stronger engagement state than the pre- certain engagement condition.
    [4]
    The control device of claim 3, wherein the calibration facility in its third calibration step has a transition phase, which enables the open loop control section to effect a gradual change of the engagement state of the clutch from the predetermined engagement state to the stronger engagement state and a stationary phase in which the open-loop control section causes the clutch to maintain the stronger engagement state.
    [5]
    The control device according to any of the preceding claims, wherein the closed-loop control section comprises an integral action control component and wherein the intermediate control signal value is determined with the integral action control component.
    BE2017 / 6036
    [6]
    A control method for driving a torque torque converter with a locking coupling (TC / LUC) connected in series with a variator (CVT) in a power train, the control method comprising providing a TC / LUC control signal (P se t) to the TC / LUC to control an engagement state of the TC / LUC, the control signal being obtained with a closed-loop driver, an open-loop driver or by a combination of an open-loop driver and a closed-loop driver loop control, the method comprising a calibration procedure with the following steps:
    supplying an open-loop based control signal to the TC / LUC with a blocked feedback control that causes gradual disconnection of the TC / LUC from an engagement state prior to the calibration procedure until it is detected that the TC / LUC assumes a slipping operational mode;
    after detecting the slipping operational mode, enabling the feedback driver to determine an intermediate value (P c , iock) of the TC / LUC control signal (P se t) for which it is detected that the TC / LUC (20) assumes a predetermined engagement state, turning off the feedback control and the enabling open-loop control in order to send an engaged state of the TC / LUC (20) on the basis of a difference between the determined intermediate value (P c, iock ) and a predetermined nominal value (Pf) that is expected to reach the predetermined engagement state.
    [7]
    The control method of claim 6, wherein the predetermined engagement state is a minimum degree of engagement of the TC / LUC required to maintain slip-free operation at a current value of a torque torque transmitted by the TC / LUC.
    [8]
    The control method according to claim 6 or 7, wherein the calibration procedure is initiated after detection of one
    BE2017 / 6036 activation condition, which at least requires the TC / LUC to be in a locked mode.
    [9]
    The control method of claim 8, wherein the activation condition comprises the expiration of a predetermined time interval (g) that has elapsed since the completion of a previous calibration procedure.
    [10]
    The control method of claim 6, wherein the occurrence of shp is detected as a slip value (ns) that is a function of a rotation speed (ne) at an input and a rotation speed (nt) at an output of the TC / LUC.
    [11]
    The control method of claim 10, wherein the slip value (ns) is the value obtained for the rotational speed (ne) at the input of the TC / LUC minus the rotational speed (nt) at the output of the TC / LUC.
    [12]
    The control method according to claim 10, wherein the slip value (ns) is the obtained value for the rotational speed (ne) at the input of the TC / LUC divided by the rotational speed (nt) at the output of the TC / LUC.
    [13]
    The control method according to any of claims 6-12, wherein an integral-action control component is used to determine the closed-loop control signal and wherein the intermediate control signal value is determined with the integral-action control component.
    [14]
    A power train in a continuously variable transmission system comprising a torque torque converter / lock clutch (TC / LUC), a forward-neutral-reverse clutch (DNR) and a variator comprising a control device according to any of claims 1 to 5.
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    同族专利:
    公开号 | 公开日
    BE1025869B1|2019-07-31|
    BE1025869A1|2019-07-24|
    WO2019129860A1|2019-07-04|
    CN111757995A|2020-10-09|
    BE1025869B9|2019-10-31|
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    法律状态:
    2019-08-28| FG| Patent granted|Effective date: 20190731 |
    2021-09-03| MM| Lapsed because of non-payment of the annual fee|Effective date: 20201231 |
    优先权:
    申请号 | 申请日 | 专利标题
    BE201706036A|BE1025869B9|2017-12-29|2017-12-29|DRIVE-DRIVE CONTROL DEVICE AND METHOD OF DRIVING A DRIVE-LINE AND DRIVE-LINE INCLUDING THE DRIVE|BE201706036A| BE1025869B9|2017-12-29|2017-12-29|DRIVE-DRIVE CONTROL DEVICE AND METHOD OF DRIVING A DRIVE-LINE AND DRIVE-LINE INCLUDING THE DRIVE|
    CN201880090152.1A| CN111757995A|2017-12-29|2018-12-28|Control device for a drive train, method for controlling a drive train and drive train comprising such a control device|
    PCT/EP2018/097094| WO2019129860A1|2017-12-29|2018-12-28|Control apparatus for a power train and method for controlling a power train as well as a power train including the control apparatus.|
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