Learning method for gear point position of AMT gear shifter

Abstract

The present application relates to the technical field of vehicle gear control, and particularly relates to a learning method for gear position of AMT gear shifter, which comprises the following steps: (1) whole vehicle power-on self-checking, if no system fault; (2) fault detection on engine side position sensor and motor side position sensor, if fault level of the engine side position sensor and the motor side position sensor is greater than or equal to 3-grade fault, then feedback that the power-on self-checking is failed, if supply voltage is greater than under-voltage value 16V, and the engine side position sensor and the motor side position sensor are both not faulty; (3) confirming that the gear shifter state enters the initialization position flag bit, and the gear position is in the neutral position; (4) controlling the system state to enter the Standby mode, sending the self-learning command through the hybrid power control system, and completing the gear self-learning. The present application can expand the efficient working area of the engine and the driving motor, improve the driving ability of the whole vehicle, and improve the economy and power performance of the whole vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle gear control, and particularly relates to a learning method for gear point position of an AMT gear shifter. BACKGROUND

[0002] An automatic transmission (Auto Transmission) is a transmission device that can automatically control gear shifting according to vehicle speed and engine speed. There are four common types of automatic transmissions, namely, a hydraulic automatic transmission (AT), a mechanical stepless automatic transmission (CVT), an electrically controlled mechanical automatic transmission (AMT) and a dual clutch automatic transmission.

[0003] During operation, the automatic transmission system identifies the gear shifters to be driven according to the gear information and control instructions from a hybrid control system (HBU) through a gear controller (SAU), and independently drives the engine-side gear shifter and the motor-side gear shifter, and can feed back information such as AMT gear shifting state, execution result and fault state to the HBU. However, the gear point position is prone to drift when the gear shifter product is shipped or used for a long time.

[0004] Therefore, there is an urgent need for a new technology to solve the above technical problems. SUMMARY

[0005] The present application aims to overcome the problems of the prior art, and provides a learning method for gear point position of an AMT gear shifter, which solves the technical problem that the gear point position is prone to drift when the gear shifter product is shipped or used for a long time in the prior art.

[0006] The above object is achieved by the following technical scheme:

[0007] A learning method for gear point position of an AMT gear shifter, comprising:

[0008] Step (1) is to perform self-checking after the vehicle is powered on, and if there is no system fault, the method proceeds to step (2);

[0009] Step (2) is to perform fault detection on an engine-side position sensor and a motor-side position sensor, and if the fault level of the engine-side position sensor and the motor-side position sensor is greater than or equal to 3, the method feeds back that the self-checking after power-on fails;

[0010] If the supply voltage is greater than an under-voltage value 16V, and neither the engine-side position sensor nor the motor-side position sensor has a fault, the method proceeds to step (3);

[0011] Step (3) confirms that the shift actuator (SAU) state enters the initialization position flag bit, and the gear position is at the neutral position, and step (4) is continued;

[0012] Step (4) controls the system state to enter the Standby mode, sends a self-learning command through the hybrid control system (HBU), and then the shift controller (SAU) drives the shift actuator to perform low gear self-learning, gives a negative duty cycle, and records the low gear calibration position. Then, the shift controller (SAU) drives the shift actuator to perform high gear self-learning, gives a negative duty cycle, and records the high gear calibration position. According to the low gear calibration position and the high gear calibration position, the average neutral gear is obtained, and the neutral gear self-learning is performed.

[0013] Step (5) is self-learning, and the duty cycle output is stopped.

[0014] Further, the shift actuator includes an engine-side shift actuator arranged on the engine side and a motor-side shift actuator arranged on the motor side.

[0015] Further, the low gear self-learning or the high gear self-learning includes:

[0016] The duty cycle, the maximum current limit, and the PWM open tube are given.

[0017] If the actual voltage is greater than or equal to the locked-rotor voltage, the process is ended.

[0018] If the actual voltage is less than the locked-rotor voltage, the gear calibration position, the actual position voltage, and the gear position voltage at this moment are recorded, and the tube is closed. The current position is maintained, the gear learning is completed, and the parameters are written.

[0019] Further, the period of the duty cycle and the size of the duty cycle are pre-set, and the current size and the change of the shift fork position are monitored. When the current of the shift actuator is equal to the set current limit 20A, and the position voltage is less than the locked-rotor voltage 10rpm, it is judged that the self-learning is passed. Otherwise, it is judged that the self-learning fails.

[0020] Further, the duty cycle includes a negative duty cycle and a positive duty cycle.

[0021] The shift controller (SAU) drives the shift actuator to perform negative duty cycle first, performs low gear self-learning, gives a negative duty cycle of 50%, a maximum current limit of 20A, and a PWM state open tube. If the actual speed at this time is less than the locked-rotor speed frequency 10Hz, the locked-rotor 200-300 cycles are maintained every cycle 5ms, and the low gear calibration position at this moment is recorded, and the PWM tube is closed.

[0022] Then, the shift controller (SAU) drives the shift actuator to perform a positive duty cycle first, performs a high gear learning, gives a positive duty cycle of 50%, a maximum current limit of 20A, a PWM state open tube, and if the actual speed is less than the locked-rotor speed frequency of 10Hz at this time, the locked-rotor is kept for 200-300 cycles, each cycle is 5ms, and the moment is recorded as the high gear calibration position, and the PWM is closed.

[0023] Further, the low gear position range is 1673-1923, and the high gear position range is 3226-3426.

[0024] Further, the neutral gear self-learning includes: obtaining the average value of the low gear calibration position and the high gear calibration position, deviating from the actual voltage position, and self-defining an allowable error.

[0025] If the deviation position voltage is greater than or equal to the allowable error, it is ended.

[0026] If the deviation position voltage is less than the allowable error, the duty cycle at this time is obtained through the position closed-loop controller (PID) control, the current position is kept, the gear learning is completed, and the parameters are written.

[0027] Further, the allowable error is 50.

[0028] Beneficial effects

[0029] The learning method of the gear point position of the AMT shift actuator provided by the application calibrates the gear through the feedback position after learning, prevents the control error caused by the signal drift of the sensor, calibrates the gear point at this time, because the gear point positions of each shift actuator are different, the gear point positions of each shift actuator are determined through the gear self-learning function, and the gear change can be accurately performed. The method can expand the efficient working area of the engine and the driving motor, improve the driving ability of the whole vehicle, and improve the economy and power of the whole vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The flowchart of the learning method of the gear point position of the AMT shift actuator is provided.

[0031] Figure 2 The low (high) gear self-learning flowchart in the learning method of the gear point position of the AMT shift actuator is provided.

[0032] Figure 3 The neutral gear self-learning flowchart in the learning method of the gear point position of the AMT shift actuator is provided. DETAILED DESCRIPTION

[0033] The application will be further described in detail below in combination with the drawings and embodiments.

[0034] As Figure 1 shown, a learning method of AMT shift point position, wherein the AMT is a combined 2-gear AMT self hybrid power system, including an engine side shift actuator and a drive motor side shift actuator, the size of the shift force is adjusted by controlling the duty cycle output, the shift displacement is controlled, and the shift function is realized; the present scheme is mainly based on a two-gear AMT commercial vehicle electric drive axle, and a corresponding two-gear AMT control system is developed to ensure the accuracy of the shift point position before the product is shipped and during long-term use, including the following steps:

[0035] Step (1) whole vehicle power-on self-test, if there is no system failure, then enter step (2);

[0036] Step (2) fault detection is performed on the engine side position sensor and the motor side position sensor; if the fault level of the engine side position sensor and the motor side position sensor is ≥3 level fault, then feedback that the power-on self-test is failed;

[0037] If the supply voltage > under-voltage value 16V, and the engine side position sensor and the motor side position sensor are both not faulty, then operate according to step (3);

[0038] Step (3) confirm the shift actuator (SAU) state to enter the initialization position flag, and the gear position is at the neutral position, continue step (4);

[0039] Step (4) the control system state enters Standby mode, and sends a self-learning command through the hybrid power control system (HBU), then the shift controller (SAU) drives the shift actuator to first perform low gear self-learning, give negative duty cycle, and record the low gear calibration position; then, the shift controller (SAU) drives the shift actuator to perform high gear self-learning, give negative duty cycle, and record the high gear calibration position; according to the low gear calibration position and the high gear calibration position, the average neutral gear position is obtained, and the neutral gear self-learning is performed;

[0040] Step (5) self-learning is completed, and the duty cycle output is stopped.

[0041] The shift actuator in the present embodiment includes an engine side shift actuator arranged on the engine side, and a motor side shift actuator arranged on the motor side.

[0042] As Figure 2 shown, wherein the low gear self-learning or the high gear self-learning includes:

[0043] give duty cycle, maximum current limit and PWM open tube;

[0044] if the actual voltage ≥ stall voltage, then end;

[0045] If the actual voltage < stall voltage, record the gear calibration position, actual position voltage and gear position voltage at this moment, and close the valve; keep the current position, and the gear learning is completed and the parameters are written.

[0046] The period and size of the duty cycle are pre-set, and the current size and shift fork position change are monitored. When the current of the gear shifting actuator is equal to the set current limiting value 20A, and the position voltage is less than the stall voltage 10 rpm, it is judged that the self-learning is passed; otherwise, it is judged that the self-learning fails.

[0047] Specifically, the duty cycle includes a negative duty cycle and a positive duty cycle;

[0048] The gear shifting controller (SAU) drives the gear shifting actuator to perform a negative duty cycle first to perform low gear self-learning, and gives a negative duty cycle of 50%, a maximum current limit of 20A, and a PWM state of opening tube. If the actual speed is less than the stall speed frequency 10Hz at this time, the stall is kept for 200-300 cycles per cycle 5ms, and the moment is recorded as the low gear calibration position, and the PWM is closed.

[0049] Then, the gear shifting controller (SAU) drives the gear shifting actuator to perform a positive duty cycle first to perform high gear learning, and gives a positive duty cycle of 50%, a maximum current limit of 20A, and a PWM state of opening tube. If the actual speed is less than the stall speed frequency 10Hz at this time, the stall is kept for 200-300 cycles per cycle 5ms, and the moment is recorded as the high gear calibration position, and the PWM is closed.

[0050] Wherein, the low gear position range is 1673-1923, and the high gear position range is 3226-3426.

[0051] As shown in Figure 3 The neutral gear self-learning in the embodiment includes: obtaining the average value of the low gear calibration position and the high gear calibration position, and the deviation of the actual voltage position, and defining the allowable error;

[0052] If the deviation position voltage ≥ allowable error, end;

[0053] If the deviation position voltage < allowable error, the duty cycle at this time is obtained through the position closed loop controller (PID) control, the current position is kept, the gear learning is completed and the parameters are written.

[0054] Wherein, the allowable error is 50.

[0055] In order to ensure the accuracy of the shift point position, trigger self-learning enablement is performed through HBU or the upper computer, so that the shift actuator performs self-learning of the shift point position and records the shift point position, and the shift position is calibrated through the feedback position after learning, so as to prevent control errors when the sensor signal drifts, and at this time, the calibration of the shift point is completed; the method is as follows:

[0056] Step (1) turn on the low-voltage power of the whole vehicle through the key, power on the HBU, hardware self-checking, and sensor zero calibration;

[0057] Step (2) perform fault detection on the engine and motor side position sensors, when the engine and motor side position sensors have a fault level greater than or equal to 3 (such as hardware overcurrent, power supply voltage undervoltage or overvoltage, communication fault with HBU, etc.), feedback that the power-on self-checking is not passed; when the power supply voltage is greater than the undervoltage value 16V, the sensor calibration flag bit is completed, and the position sensor has no fault;

[0058] Step (3) the SAU state enters the initialization position flag bit, and the shift position is at the neutral position;

[0059] Step (4) the engine side shift actuator, the system state enters the Standby mode (sleep mode of the electronic control system), HBU sends a self-learning instruction, then the engine side sends duty cycles to the positive and negative directions, the cycle and the size of the duty cycle are pre-set; and monitor the current size and the change of the shift fork position;

[0060] When the shift actuator current is equal to the set current limit value 20A and the position voltage is less than the locked-rotor voltage 10rpm, it is judged that the self-learning is passed; otherwise, it is judged that the self-learning fails;

[0061] Step (5) the motor side shift actuator, the system state enters the Standby mode, HBU sends a self-learning instruction, then the motor side sends duty cycles to the positive and negative directions in turn, the cycle and the size of the duty cycle are pre-set; and monitor the current size and the change of the shift fork position;

[0062] When the shift actuator current is equal to the set current limit value 20A and the position voltage is less than the locked-rotor voltage 10rpm, it is judged that the self-learning is passed; otherwise, it is judged that the self-learning fails;

[0063] Step (6) stop the duty cycle output.

[0064] The above step (4) includes:

[0065] Step (4-1) the engine side shift performs negative duty cycle first, gives the given duty cycle, the maximum current limit, the PWM state open tube, when the actual speed is less than the locked-rotor speed at this time, keeps the locked-rotor for 200 cycles, records the shift position calibration position at this moment, and closes the tube;

[0066] Specifically, the engine side shift first performs a negative duty ratio, and low gear self-learning is performed. A negative duty ratio of 50%, a maximum current limit of 20A, and a PWM state of opening the tube are given. If the actual speed at this time is less than the locked-rotor speed frequency of 10Hz, the locked-rotor is maintained for 300 cycles, each cycle being 5ms, and the gear calibration position at this moment (low gear position range 1673-1923) is recorded. The PWM is closed.

[0067] Step (4-2) The engine side shift first performs a positive duty ratio. A duty ratio, a maximum current limit, and a PWM state of opening the tube are given. When the actual speed at this time is less than the locked-rotor speed, the locked-rotor is maintained for 200 cycles, and the gear calibration position at this moment is recorded. The tube is closed.

[0068] Specifically, the engine side shift first performs a positive duty ratio, and high gear self-learning is performed. A positive duty ratio of 50%, a maximum current limit of 20A, and a PWM state of opening the tube are given. If the actual speed at this time is less than the locked-rotor speed frequency of 10Hz, the locked-rotor is maintained for 300 cycles, each cycle being 5ms, and the gear calibration position at this moment (high gear position range 3226-3426) is recorded. The PWM is closed.

[0069] Step (4-3) Through the negative duty ratio gear calibration position and the positive duty ratio calibration position obtained, when the error thereof is less than the gear self-learning return to neutral gear allowable error of 50, the duty ratio at this time is obtained through PID control, and the gear calibration position at this moment is obtained.

[0070] Specifically, through the negative duty ratio gear calibration position and the positive duty ratio calibration position obtained, neutral gear self-learning is performed. When the gear self-learning return to neutral gear allowable error erro is 50, the duty ratio at this time is obtained through position closed loop PID control. The Kp setting is 0.0005, the Ki is 0.02, and the Kd is set to 0, so as to improve the response speed and reduce the error. The neutral gear calibration position at this moment (neutral gear position range 2550-2650) is obtained, and the PWM is closed.

[0071] The above step (5) includes:

[0072] Step (5-1) The motor side shift first performs a negative duty ratio. A duty ratio, a maximum current limit, and a PWM state of opening the tube are given. When the actual speed at this time is less than the locked-rotor speed, the locked-rotor is maintained for 200 cycles, and the gear calibration position at this moment is recorded. The tube is closed.

[0073] Step (5-2) The motor side shift first performs a positive duty ratio. A duty ratio, a maximum current limit, and a PWM state of opening the tube are given. When the actual speed at this time is less than the locked-rotor speed, the locked-rotor is maintained for 200 cycles, and the gear calibration position at this moment is recorded. The tube is closed.

[0074] Step (5-3) is to obtain the negative duty ratio block demarcation position and the positive duty ratio demarcation position, when the error is less than the block self-learning return neutral position allowable error 50, the duty ratio at this time is obtained through PID control, and the block demarcation position at this time is obtained

[0075] The above specific values are optimal values obtained through calibration, and actual calibration needs to be performed every time a new gear shifter is used.

[0076] The above describes only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any change or replacement within the technical range disclosed by the present application can be thought of by anyone skilled in the art, and is covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for learning the gear position of an AMT shift actuator, characterized in that, include: Step (1) Power on the vehicle and perform a self-test. If there is no system fault, proceed to step (2). Step (2) Perform fault detection on the engine-side position sensor and the motor-side position sensor; if the fault level of the engine-side position sensor and the motor-side position sensor is ≥ level 3, then the power-on self-test fails. If the power supply voltage is greater than the undervoltage value of 16V, and neither the engine-side position sensor nor the motor-side position sensor is faulty, then proceed with step (3). Step (3) Confirm that the shift actuator is in the initial position flag and the gear position is in neutral, then continue to step (4). Step (4) The control system enters Standby mode. A self-learning command is sent through the hybrid power control system. The shift controller drives the shift actuator to perform low gear self-learning, gives a negative duty cycle, and records the low gear calibration position. Then, the shift controller drives the shift actuator to perform high gear self-learning, gives a positive duty cycle, and records the high gear calibration position. Based on the low gear calibration position and the high gear calibration position, the average neutral gear position is obtained, and neutral gear self-learning is performed. Step (5) After self-learning is completed, the power supply is turned off and the duty cycle output is stopped; The low-gear self-learning or the high-gear self-learning includes: Given the duty cycle, maximum current limit, and PWM switching; If the actual voltage is greater than or equal to the stall voltage, then the process ends. If the actual voltage is less than the stall voltage, record the current gear calibration position, actual position voltage, and gear position voltage, and turn off the control tube; maintain the current position, the gear learning is complete, and the parameters are written. The duty cycle period and the duty cycle size are preset, and the current size and shift fork position changes are monitored. When the current of the shift actuator is equal to the set maximum current limit of 20A and the position voltage is less than the stall voltage of 10rpm, it is judged that the self-learning is successful; otherwise, it is judged that the self-learning is unsuccessful. The shift controller drives the shift actuator to first execute a negative duty cycle for low-gear self-learning. Given a negative duty cycle of 50%, a maximum current limit of 20A, and PWM enabled, if the actual rotational speed frequency is less than the stalled speed frequency by 10Hz, the stalled position is maintained for 200-300 cycles, each cycle being 5ms, and this moment is recorded as the low-gear calibration position, at which point the PWM is turned off. Then, the shift controller drives the shift actuator to execute a positive duty cycle for high-gear learning. Given a positive duty cycle of 50%, a maximum current limit of 20A, and PWM enabled, if the actual rotational speed frequency is less than the stalled speed frequency by 10Hz, the stalled position is maintained for 200-300 cycles, each cycle being 5ms, and this moment is recorded as the high-gear calibration position, at which point the PWM is turned off.

2. The method for learning the gear position of an AMT shift actuator according to claim 1, characterized in that, The shift actuator includes an engine-side shift actuator located on the engine side and a motor-side shift actuator located on the motor side.

3. The method for learning the gear position of an AMT shift actuator according to claim 1, characterized in that, The neutral gear self-learning includes: obtaining the average value of the low gear calibration position and the high gear calibration position, the deviation from the actual position, and defining a custom allowable error; If the deviation is greater than or equal to the allowable error, then the process ends. If the deviation is less than the allowable error, the duty cycle at this time is obtained through the position closed-loop controller, the current position is maintained, and the neutral gear learning is completed and written into the parameters.

4. The method for learning the gear position of an AMT shift actuator according to claim 3, characterized in that, The allowable error is 50.

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