Hybrid power AMT gear shifting control method and system

Abstract

The invention discloses a hybrid power AMT gear shifting control method and system, and relates to the technical field of vehicle gear shifting. The method comprises the steps that whether a transmission meets gear shifting conditions or not is judged according to driving information; determining a target gear value according to the current vehicle state; the power source output torque is gradually reduced according to the target gear value; gear picking operation is carried out through an actuator; adjusting the rotating speed of the motor according to the rotating speed difference of the actuator; controlling the transmission to engage a gear according to the target gear value; and gradually restoring the power source output torque according to the target torque value. According to the technical scheme, high-precision control over the rotating speed of the motor of the commercial vehicle can be achieved, the gear shifting success rate of the hybrid power AMT system can be effectively increased, and high application value is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle shifting, and particularly relates to a hybrid AMT shifting control method and system. Background Art

[0002] As a production tool, commercial vehicles promote economic development. Due to their complex usage scenarios, safety accidents frequently occur during their use. How to improve the safety of commercial vehicles has become a major problem in the production process of commercial vehicles. As one of the main control systems of commercial vehicles, the hybrid AMT system is crucial for the safety performance of commercial vehicles. In the traditional hybrid AMT system, speed regulation is performed through a clutch and a brake during the shifting process. This method has poor motor speed regulation responsiveness, a long vehicle shifting time, and even a shifting failure may occur due to the rotational speed difference of the actuator exceeding the reasonable range. Therefore, the research and development of a simple and efficient method to improve the shifting success rate of the hybrid AMT system is extremely urgent.

[0003] Currently, most of the existing methods to improve the shifting success rate of the hybrid AMT system have certain defects in one aspect. For example, Patent Application Publication CN105197006A discloses a pure electric drive starting control method for a hybrid vehicle. This method controls the driving motor to perform speed closed-loop control when the vehicle starts, requiring the rotational speed of the driving motor to remain at the target speed, and slowly engages the clutch in the gearbox. The driving motor controls the vehicle to start slowly through the gearbox; when the vehicle shifts gears, the driving motor exits the speed closed-loop control to achieve torque control of the driving motor. The torque executed by the driving motor is the superposition of the actual torque of the driving motor and the driver's required torque; however, in the face of a steep road, the acceleration torque of the vehicle often lacks, and its shifting strategy based on the combination of rotational speed and throttle cannot meet the requirements of complex operating conditions. Therefore, based on this problem, the present application proposes a hybrid AMT shifting control method and system. Summary of the Invention

[0004] Technical Objectives In order to solve the above problems, the objective of the present invention is to provide a hybrid AMT shifting control method and system, which realizes high-precision control of the rotational speed of the commercial vehicle motor, can effectively improve the shifting success rate of the hybrid AMT system. The application scenarios of this method and system are extensive. By optimizing the control method during the shifting process of the AMT system, the response time of motor speed regulation is shortened, and the shifting success rate of the AMT system is improved.

[0005] Technical Solutions To achieve the above object, the present invention provides a hybrid AMT shift control method and system, which determines the shift requirement of the vehicle according to driving information and vehicle state, determines the target gear value of the vehicle by accurately calculating the current acceleration of the vehicle, compensates for the reduced output torque during shifting, and synchronizes the engine speed and clutch speed after shifting ends, thereby achieving smooth control of the torque during vehicle shifting and effectively improving the shift success rate of the hybrid AMT system.

[0006] In a first aspect, the present invention provides a hybrid AMT shift control method, including: Determine whether the transmission meets the shift condition according to driving information; Determine the target gear value according to the current vehicle state; Gradually reduce the power source output torque according to the target gear value; Perform a gear disengagement operation through an actuator; Adjust the motor speed according to the speed difference of the actuator; Control the transmission to engage a gear according to the target gear value; Gradually restore the power source output torque according to the target torque value.

[0007] Further, the shift conditions of the transmission include the vehicle speed, the engine speed, and the throttle opening; calculate the vehicle acceleration according to the throttle opening and the mapping relationship between the maximum torque output within each gear range and the engine speed, and determine the target gear value according to the vehicle speed, the vehicle acceleration, and a preset acceleration threshold.

[0008] Further, before reducing the power source output torque, the method outputs the shift requirement of the transmission to a control module to determine this shift requirement; the control module determines whether this shift requirement needs to be satisfied according to the current mode of the vehicle and whether it is performing energy recovery.

[0009] Even further, if the control module believes that the current moment is not the best shift timing when evaluating the shift request, the control module will reject this shift request.

[0010] Further, after the control module passes this shift request, the transmission issues an instruction to the power source to gradually reduce its output torque until the torque is 0; the power source includes a motor and an engine.

[0011] Further, after the power source output torque is reduced to 0, the transmission controls the actuator of the gearbox to perform a gear disengagement operation, that is, to withdraw the current gear.

[0012] Further, after the transmission successfully shifts into neutral, the transmission issues a request to control the motor speed so that the speed difference of the actuator remains within a reasonable range.

[0013] Further, the target speed for motor adjustment is determined based on the current gear position, target gear position, vehicle speed, and input speed of the vehicle.

[0014] Further, after the speed difference of the actuator remains within a reasonable range, the transmission performs a gear shifting operation. Further, the steps for the transmission to shift gears include synchronization, during synchronization, starting to lock, and completing the lock. Among them, synchronization means preparing for gear meshing, starting to lock means gear meshing, and completing the lock means the gears are fully meshed; before the synchronization meshing mechanism of the transmission disconnects from its corresponding gear, the hybrid AMT shift control method achieves torque compensation through torque handover.

[0015] Further, when the system confirms that the transmission is in gear, the transmission controls the power source to gradually resume its output torque until the torque reaches the target torque value set by the control module.

[0016] Further, for smooth control of torque during vehicle gear shifting, it includes compensating for the reduced output torque during gear shifting and achieving synchronous control of the engine speed and clutch speed after gear shifting.

[0017] Further, the method also includes a coordinated control method for regenerative braking and mechanical braking, which dynamically allocates the ratio of regenerative braking and mechanical braking according to the braking demand and battery state, and adjusts the intensity of regenerative braking and mechanical braking by coordinating the control of the engine, motor, clutch, and transmission during gear shifting.

[0018] Further, the method also includes a self-learning method for the deviation between the clutch and the shift position, which compensates for manufacturing errors and wear by learning the actual position deviation between the clutch and the shift mechanism.

[0019] In a second aspect, the present invention also provides a hybrid AMT shift control system. The system is based on the method described in the first aspect above and includes: An acquisition module for acquiring vehicle driving information; A calculation module for calculating the current acceleration of the vehicle; A torque compensation module for compensating when the torque decreases; A control module for judging the shift demand and managing and allocating torque; An execution module for executing the command signal of the control module.

[0020] Furthermore, the vehicle driving information includes the maximum output torque of the engine and the drive motor, the throttle opening, the wheel speed, etc.

[0021] Furthermore, the execution module includes a transmission, a gearbox, etc.; the transmission includes a main shaft, a driven shaft, a drive shaft, a plurality of synchronous meshing mechanisms and a plurality of gears, the main shaft is contained inside the driven shaft and the main shaft and the driven shaft rotate independently, the drive shaft is deployed in parallel with the main shaft and the driven shaft, the gears deployed on the drive shaft are always in a meshing state with the gears deployed on the main shaft and the driven shaft, so that each shaft is connected through the plurality of synchronous meshing mechanisms and the plurality of gears.

[0022] In a third aspect, the present invention also provides a computer device, comprising a processor and a memory, wherein the processor is connected to the memory, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the computer device executes the aforementioned hybrid AMT shift control method.

[0023] In a fourth aspect, the present invention further provides a computer-readable storage medium, wherein a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the aforementioned hybrid AMT shift control method is implemented.

[0024] The present invention determines the shifting demand of the vehicle according to driving information and vehicle status, and determines the target gear value of the vehicle by accurately calculating the current acceleration of the vehicle; by compensating for the reduced output torque during the shifting and realizing synchronous control of the engine speed and clutch speed after the shifting, the smoothness control of the torque during the vehicle shifting is realized; the proportion of regenerative braking and mechanical braking is dynamically allocated according to the braking demand and battery status, and the strength of regenerative braking and mechanical braking is adjusted by coordinating and controlling the engine, motor, clutch and transmission during the shifting process; and the actual position deviation of the clutch and shifting mechanism is learned to compensate for manufacturing errors and wear. The method and system realize high-precision control of the motor speed of commercial vehicles, and can effectively improve the shifting success rate of the hybrid AMT system. The method and system have a wide range of application scenarios. By optimizing the control method during the shifting process of the AMT system, the response time of the motor speed regulation is shortened, and the shifting success rate of the AMT system is improved.

[0025] Beneficial Effects By implementing the hybrid AMT shift control method and system provided by the present invention, the following technical effects are achieved: (1) Determine the gear shifting requirement of the vehicle based on the driving information and vehicle status, and determine the target gear value of the vehicle by accurately calculating the current acceleration of the vehicle; it shortens the response time of the motor speed regulation, improves the gear shifting success rate of the AMT system; reduces the oscillation of the vehicle speed during the gear shifting process, enhances the smoothness of the gear shifting process, and realizes the optimal power output.

[0026] (2) Compensate for the reduced output torque during gear shifting and realize the synchronous control of the engine speed and clutch speed after gear shifting, so as to realize the smooth control of the torque during vehicle gear shifting; it avoids the power interruption during the gear shifting process, improves the smoothness of gear shifting and driving comfort; reduces the impact and vibration during the gear shifting process, enhances the gear shifting quality; reduces the energy loss during the gear shifting process, and improves the fuel economy of the whole vehicle.

[0027] (3) Dynamically allocate the proportion of regenerative braking and mechanical braking according to the braking requirement and battery status, and adjust the intensity of regenerative braking and mechanical braking by coordinating the control of the engine, motor, clutch and transmission during the gear shifting process; it converts the kinetic energy during the vehicle braking process into electrical energy, improves the energy utilization rate; by accurately controlling the intervention mode of regenerative braking and mechanical braking, reduces the impact and vibration during the braking process, and enhances the dynamic performance of the vehicle.

[0028] (4) Compensate for the manufacturing error and wear by learning the actual position deviation of the clutch and gear shifting mechanism; it improves the accuracy of gear shifting; by self-learning the key positions of the clutch and gear shifting mechanism, ensures the stability of the AMT system; reduces the power interruption and impact during the gear shifting process, and further enhances the smoothness of the gear shifting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To make the above hybrid AMT gear shifting control method and system of the present invention more obvious and understandable, the drawings required for the specific implementation manners of the present invention will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those skilled in the art can obtain other drawings according to these drawings without creative efforts.

[0030] Figure 1 It shows a schematic diagram of the hybrid AMT gear shifting control method; Figure 2 It shows a schematic diagram of the hybrid AMT gear shifting control process. DETAILED DESCRIPTION OF THE INVENTION

[0031] Example 1: A hybrid AMT gear shifting control method is provided, and the gear shifting control method is as Figure 1 shown, and the gear shifting control process is as Figure 2As shown, the method includes: Judge whether the transmission meets the shifting condition according to the driving information; Determine the target gear value according to the current vehicle state; Gradually reduce the output torque of the power source according to the target gear value; Perform a gear disengaging operation through the actuator; Adjust the motor speed according to the speed difference of the actuator; Control the transmission to engage a gear according to the target gear value; Gradually restore the output torque of the power source according to the target torque value.

[0032] The shifting conditions of the transmission include the vehicle speed, the engine speed, and the throttle opening; calculate the vehicle acceleration according to the throttle opening and the mapping relationship between the maximum torque output within each gear range and the engine speed, and determine the target gear value according to the vehicle speed, the vehicle acceleration, and a preset acceleration threshold.

[0033] Before reducing the output torque of the power source, the method outputs the shifting requirement of the transmission to the control module to determine this shifting requirement; the control module determines whether this shifting requirement needs to be satisfied according to the current mode of the vehicle and whether it is performing energy recovery.

[0034] If the control module believes that the current moment is not the best shifting moment when evaluating the shifting request, the control module will reject this shifting request.

[0035] After the control module passes this shifting request, the transmission will issue an instruction to the power source to gradually reduce its output torque until the torque is 0; the power source includes a motor and an engine.

[0036] When the output torque of the power source is reduced to 0, the transmission controls the actuator of the gearbox to perform a gear disengaging operation, that is, to withdraw the current gear.

[0037] After the gearbox successfully shifts into neutral, the transmission issues a request to control the motor speed so that the speed difference of the actuator remains within a reasonable range.

[0038] The target speed adjusted by the motor is determined according to the current gear, the target gear, the vehicle speed, and the input speed of the vehicle.

[0039] After the speed difference of the actuator remains within a reasonable range, the transmission performs a gear engaging operation, The steps for the transmission to engage a gear include synchronization, during synchronization, starting to lock, and locking completed. Among them, synchronization means gear meshing preparation, starting to lock means gear meshing, and locking completed means the gears are fully meshed; before the synchronization engagement mechanism of the transmission is disconnected from its corresponding gear, the hybrid AMT shift control method achieves torque compensation through torque handover.

[0040] When the system confirms that the transmission is in gear, the transmission control power source gradually resumes its output torque until the torque reaches the target torque value set by the control module.

[0041] For the smooth control of torque during vehicle shifting, it includes compensating for the reduced output torque during shifting and achieving synchronous control of the engine speed and clutch speed after shifting.

[0042] The method also includes a coordinated control method for regenerative braking and mechanical braking, which dynamically allocates the ratio of regenerative braking and mechanical braking according to the braking demand and battery state, and adjusts the intensity of regenerative braking and mechanical braking by coordinating the control of the engine, motor, clutch, and transmission during shifting. Specifically, it includes: establishing a dynamic model of the hybrid vehicle to simulate the driving characteristics of the vehicle under different working conditions; designing a shifting strategy based on the driving state of the vehicle considering maximizing the energy recovery efficiency while ensuring smooth shifting; during regenerative braking, reasonably allocating the motor regenerative braking force and mechanical braking force to ensure maximizing energy recovery while meeting the braking performance requirements; ensuring vehicle braking stability and energy recovery efficiency under different road conditions through the coordinated control strategy of regenerative braking and mechanical braking. The application of the coordinated control method for regenerative braking and mechanical braking can increase the energy recovery efficiency of the hybrid AMT shift control method by about 3%.

[0043] Embodiment 2: On the basis of the foregoing embodiment, the method adds a self-learning method for the deviation between the clutch and the shifting position, and compensates for manufacturing errors and wear by learning the actual position deviation between the clutch and the shifting mechanism; First, it is necessary to perform self-learning on the key positions of the clutch, including the positions of the separation point, engagement point, and slip friction point. The self-learning process is represented by the following formula:

[0044] In the formula, is the clutch torque; is the target torque; is the target speed; is the current speed; is the coefficient adjusted according to the wear condition.

[0045] The self-learning process of the transmission involves the exact positions of the gear positions. Its self-learning control method includes: in the P or N gear positions, ensuring that the engine speed is within the range of plus or minus 100 rpm of the control module target value; in the P or N gear positions, ensuring that the engine torque is within the range of plus or minus 4 Nm of the control module target value; the engine temperature is above 60 °C, and the transmission temperature is between 20 °C and 60 °C.

[0046] During the gearshift process, the coordinated control of the engine, motor, clutch, and transmission is used to reduce the power interruption time and gearshift shock, thereby improving the gearshift quality. Its control strategy is expressed by the following formula:

[0047] In the formula, is the total cost function; is the cost function of the tracking error; is the cost function of the control energy; is the cost function of the driving comfort; 、 and are the weight coefficients.

[0048] Through the model predictive control strategy, based on the vehicle's dynamic model, the dynamic response during the clutch engagement process is predicted, and the control parameters are adjusted in real time to achieve a smooth gearshift. The prediction model is expressed by the following formula:

[0049] Where, is the output increment at the th step; are the model parameters; is the control increment at the th step; is the deviation term of the prediction model; is the control time domain.

[0050] By precisely controlling the gearshift actuator to adapt to changes in different driving conditions and vehicle states, the adaptive PID control method is expressed by the following formula:

[0051] In the formula, is the control input; is the proportional gain; is the error; is the integral gain; is the derivative gain; is the gain adjusted according to the frequency response; is the system frequency response function.

[0052] For example, assume that the current speed of the vehicle is 50 km / h, the engine speed is 1000 rpm, and the motor speed is 0 rpm, and it is necessary to shift the vehicle from gear 2 to gear 3.

[0053] Assume , , , ;

[0054] Learn the gear position through the following steps: In the P or N gear, ensure that the engine speed is within the range of plus or minus 100 rpm of the control module target value; in the P or N gear, ensure that the engine torque is within the range of plus or minus 4 Nm of the control module target value.

[0055] Assume , , , the target vehicle speed is 60 km / h:

[0056]

[0057]

[0058]

[0059] Assume , , , , , , : Assume that the next 3 time steps are: , , ;

[0060]

[0061]

[0062] Assume , , , , , :

[0063] The effect of the self-learning method for the deviation between the clutch and the shift position is shown in Table 1: Table 1. Summary of the effect of the self-learning method for clutch and shift position deviation Indicator Before applying the method After applying the method Proportion of effect improvement Shift time (s) 0.8 0.6 25% Shift smoothness (unit) 3.5 1.2 64.3% Fuel efficiency (L / 100km) 5.8 5.5 5.2% Response time (ms) 500 300 40% As shown in Table 1, after the clutch and shift position deviation self-learning method is optimized, the shift time of the hybrid AMT method is significantly reduced, the shift smoothness is greatly improved, the fuel consumption per 100 kilometers is reduced from 5.8 liters to 5.5 liters, and the system response time is reduced by 200 milliseconds; this shows that the clutch and shift position deviation self-learning method can effectively improve the performance of the hybrid AMT system, especially in terms of shift smoothness and shift time.

[0064] Embodiment 3: Based on the above embodiments, a hybrid AMT shift control system is provided, which specifically includes: A collection module, used for collecting vehicle driving information; A calculation module, used to calculate the current acceleration of the vehicle; A torque compensation module for compensating when the torque is reduced; A control module that determines the need for shifting and manages and distributes torque; The execution module is used to execute the command signal of the control module.

[0065] Vehicle driving information includes the maximum output torque of the engine and drive motor, throttle opening, wheel speed, etc.

[0066] The execution module includes a transmission, a gearbox, etc.; the transmission includes a main shaft, a driven shaft, a drive shaft, multiple synchronous meshing mechanisms and multiple gears. The main shaft is contained inside the driven shaft and the main shaft and the driven shaft rotate independently. The drive shaft is deployed in parallel with the main shaft and the driven shaft. The gears deployed on the drive shaft are always in a meshing state with the gears deployed on the main shaft and the driven shaft, so that each shaft is connected through the multiple synchronous meshing mechanisms and the multiple gears.

[0067] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable non-transient storage media containing computer-usable program code.

[0068] The present invention can provide computer program instructions to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce means for implementing the system.

[0069] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to work in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including an instruction device that implements the functions of the system.

[0070] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, so that the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions of the system.

Claims

1. A hybrid AMT shift control method, characterized in that: Including: Judging whether the transmission meets the shifting condition according to the driving information; Determining the target gear value according to the current vehicle state; Gradually reducing the output torque of the power source according to the target gear value; Performing a gear disengaging operation through an actuator; Adjusting the motor speed according to the speed difference of the actuator; Controlling the transmission to engage gears according to the target gear value; Gradually restoring the output torque of the power source according to the target torque value; The method further includes a coordinated control method for regenerative braking and mechanical braking and a self-learning method for the deviation between the clutch and the shifting position.

2. The method according to claim 1, wherein: The shifting conditions of the transmission include the vehicle speed, the engine speed, and the throttle opening; the vehicle acceleration is calculated according to the throttle opening and the mapping relationship between the maximum torque output in each gear range and the engine speed, and the target gear value is determined according to the vehicle speed, the vehicle acceleration, and a preset acceleration threshold.

3. The method according to claim 1, characterized in that: Before reducing the output torque of the power source, the method outputs the shifting requirement of the transmission to the control module to determine the shifting requirement; the control module determines whether the shifting requirement needs to be met according to the current mode of the vehicle and whether it is performing energy recovery.

4. The method according to claim 3, characterized in that: For smooth control of torque during vehicle shifting, it includes compensating for the reduced output torque during shifting and synchronously controlling the engine speed and the clutch speed after shifting.

5. The method according to claim 4, wherein: The steps for the transmission to engage gears include synchronization, during synchronization, starting to lock, and locking completed; before the synchronizing mechanism of the transmission disconnects from its corresponding gear, the hybrid AMT shifting control method realizes torque compensation through torque handover.

6. The method according to claim 1, characterized in that: The coordinated control method for regenerative braking and mechanical braking specifically includes: dynamically allocating the ratio of regenerative braking and mechanical braking according to the braking demand and the battery state, and adjusting the intensity of regenerative braking and mechanical braking by coordinating the control of the engine, motor, clutch, and transmission during the shifting process.

7. The method according to claim 1, wherein: The self-learning method for the deviation between the clutch and the shifting position specifically includes: compensating for manufacturing errors and wear by learning the actual position deviation between the clutch and the shifting mechanism.

8. A hybrid AMT shifting control system, characterized in that: The implementation of the system is based on the method according to any one of claims 1-7; The system includes: An acquisition module for acquiring vehicle driving information; A calculation module for calculating the current acceleration of the vehicle; A torque compensation module for compensating when the torque is reduced; A control module for judging the shifting requirement and managing and distributing torque; An execution module for executing the command signal of the control module.

9. A computer device, comprising a processor and a memory, the processor being connected to the memory, the memory being used for storing computer programs, characterized in that: The processor is used to execute the computer program stored in the memory so that the computer device executes the method according to any one of claims 1-7.

10. A computer-readable storage medium storing a computer program therein, characterized in that: When the computer program is run, it realizes the method according to any one of claims 1-7.

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