A Shift Control Method for Motor Transmission Drive System Based on Chance Constraints

Abstract

The present invention belongs to the technical field of electric drive shift control, and discloses a shift control method for a motor transmission drive system based on chance-constrained programming, comprising the following steps: constructing a motor transmission and establishing a mathematical model thereof; collecting operation signals of a shift actuator of the motor transmission, sensing signals of the shift actuator, sensing signals of a drive motor, and load signals; combining the operation signals of the shift actuator and the sensing signals of the shift actuator to judge the current position and the expected position of a synchronizer sleeve, and designing a shift logic for the motor transmission; based on driver signals, sensing signals of the shift actuator, sensing signals of the drive motor, load signals, and the shift logic of the motor transmission; compared with traditional shift control methods, by imposing chance constraints on uncertain factors in the shift process and combining with the optimization requirements in the shift process, a gear positioning method for reducing position accuracy and enhancing shift efficiency is designed to achieve a faster and more efficient motor shift control.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric drive shift control, and particularly relates to a shift control method for a motor transmission drive system based on chance constraints. Background Art

[0002] A motor transmission is a speed-changing device that drives a sliding sleeve through a shift motor to synchronize the sliding sleeve with a gear ring, and is an important part of vehicle automation. Conventional shift control includes five stages: torque unloading, fork disengaging, speed synchronization, fork engaging, and torque recovery. During the shift process and under steady state, there are uncertain errors such as body vibration, shift resistance, and tooth alignment position. There is a certain displacement deviation between the actual position of the synchronizer and the expected position of the corresponding gear, resulting in certain oscillations, extending the shift time and power interruption, and causing energy loss.

[0003] To solve the above problems, a tooth alignment control method has been proposed in recent years. This method actively controls the tooth alignment error between the sliding sleeve and the gear ring of the transmission to improve the success rate of a single shift and reduce shift impact problems such as gear clash; various shift control optimizations combining modern control methods have been proposed to reduce synchronizer oscillations by increasing the dynamic response speed of the gear ring.

[0004] However, the above shift methods lack a process for constraining uncertain errors and do not solve the problem of synchronizer offset caused by oscillations, resulting in problems such as sliding sleeve wear and energy loss in the vehicle; therefore, there is a problem in the prior art of lacking constraints on uncertain factors during the shift process and optimizing the shift process. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a shift control method for a motor transmission drive system based on chance constraints, which solves the problem in the prior art of lacking constraints on uncertain factors during the shift process and optimizing the shift process.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A shift control method for a motor transmission drive system based on chance constraints includes the following steps:

[0008] Construct a motor transmission and establish a mathematical model of the motor transmission;

[0009] Collect the operation signal of the shift actuator, the sensing signal of the shift actuator, the sensing signal of the drive motor, and the load signal of the motor transmission;

[0010] Combine the operation signal of the shift actuator and the sensing signal of the shift actuator to judge the current position and the expected position of the sliding sleeve, and design the shift logic of the motor transmission;

[0011] Based on the driver signal, the shift actuator sensing signal, the drive motor sensing signal, the load signal, and the motor transmission shift logic, during the up / downshift process, the servo controller is used to control the shift actuator motor to switch between multiple gears;

[0012] Based on chance constraints, according to the uncertain factors during the shifting process, chance constraints are imposed on the lateral displacement of the synchromesh sleeve.

[0013] The uncertain factors during the shifting process include the tooth alignment error and the shifting resistance during the shifting process.

[0014] The constructed motor transmission includes: a drive motor, a mechanical gearbox, a load motor, two shift actuator motors, sensors, and a servo controller; among them, the mechanical gearbox adopts a configuration of two sets of transmission gears, one shift motor, two sets of shift forks, and two sets of synchromesh sleeves.

[0015] The shift actuator sensing signal includes the angle sensor signals of the two shift actuator motors and the position signals of the two sets of synchromesh sleeves;

[0016] The drive motor sensing signal includes the torque signal, the speed signal, and the fault signal of the drive motor;

[0017] The load signal includes the speed signal and the torque signal of the wheel hub when simulating the movement of the whole vehicle;

[0018] The driver signal includes the throttle opening.

[0019] When the shift actuator motor in the motor transmission adopts a brushless DC motor, the motor electromagnetic torque equation and the motion equation are established as:

[0020]

[0021] Among them, is the electromagnetic torque; is the phase current; is the phase voltage; is the mechanical angular velocity; is the mechanical angular acceleration; is the number of motor pole pairs; is the magnetic flux of the permanent magnet rotor; is the back electromotive force waveform function of each item; is the moment of inertia of the motor rotor; is the damping coefficient; is the motor frictional resistance torque; is the mechanical load torque of the motor.

[0022] The transmission mechanism of the shift motor includes a planetary reduction mechanism, a two-stage transmission gear set, and a shift finger. The planetary reduction mechanism is modeled as:

[0023]

[0024] Among them, is the output torque of the planetary reduction mechanism; T m is the input torque of the planetary reduction mechanism; T sensor represents the additional mechanical load torque introduced by the sensor; is the equivalent moment of inertia of the planetary reduction mechanism; is the damping coefficient of the planetary reduction mechanism; is the output torque of the output shaft; is the equivalent moment of inertia of the output shaft; is the damping coefficient of the output shaft; is the frictional torque of the output shaft; is the reduction ratio of the planetary reduction mechanism; is the transmission efficiency of the planetary reduction mechanism; is the reduction ratio of the two-stage reduction mechanism; is the transmission efficiency of the two-stage reduction mechanism; is the shifting resistance; is the effective radius of the shifting finger; is the rotation angle of the shifting finger.

[0025] When the drive motor of the motor transmission uses a permanent magnet synchronous motor, the permanent magnet synchronous motor is modeled as:

[0026]

[0027] Among them, is the mechanical angular velocity of the motor; is the sum of the moments of inertia of the input shaft and the transmission; is the damping coefficient, , are the direct-axis and quadrature-axis currents; is the number of pole pairs; are the direct-axis and quadrature-axis inductances; is the motor magnetic flux; is the electromagnetic torque; is the load torque.

[0028] Based on the upper and lower limits of the uncertain factors during the shifting process, the optimization method for the shifting process based on chance-constrained programming is designed as:

[0029]

[0030] Among them, is the shifting torque input; For the shifting resistance and tooth alignment error; Represents the time / energy consumption required for the shifting process; Represents the expected position after the engaging sleeve shifts gears; Is the expected position of the corresponding gear position; Is the permitted error; Is the variable compensation for the input according to uncertain factors Is the coefficient matrix; Are the upper and lower limits of the uncertainty error; Is the introduced slack variable; W Is the compensation coefficient matrix.

[0031] Advantages of the present invention:

[0032] Compared with the traditional shifting control method, the method of the present invention takes into account the uncertain factors of shifting resistance and tooth alignment error during the shifting process, and based on the chance-constrained principle, by imposing chance constraints on the uncertain factors of the shifting process and combining with the optimization requirements of the shifting process, designs a gear position positioning method that reduces position accuracy and enhances shifting efficiency, realizes a faster and more efficient motor shifting control, minimizes the time and energy loss during the gear engagement process, meets the requirements of shifting speed and reliability guarantee, and realizes further optimization of the shifting process. Brief description of the drawings

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0034] Figure 1 Is a schematic diagram of the motor transmission and its shifting mechanism of the present invention;

[0035] Figure 2 Is a schematic diagram of the chance-constrained shifting control process of the present invention;

[0036] Figure 3 Is a schematic diagram of the chance-constrained shifting principle of the present invention. Detailed implementation manners

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0038] Such as Figures 1 to 3As shown in the figure, a shift control method for a motor transmission drive system based on chance constraints includes the following steps:

[0039] Construct a motor transmission and establish a mathematical model of the motor transmission;

[0040] Collect the operation signal of the shift actuator, the sensing signal of the shift actuator, the sensing signal of the drive motor, and the load signal of the motor transmission;

[0041] Combine the operation signal of the shift actuator and the sensing signal of the shift actuator to judge the current position and the expected position of the synchronizer sleeve, and design the shift logic of the motor transmission;

[0042] Based on the driver signal, the sensing signal of the shift actuator, the sensing signal of the drive motor, the load signal, and the shift logic of the motor transmission, during the up / down shift process, use the servo controller to control the shift actuator motor to switch between multiple gears;

[0043] Based on chance constraints, according to the uncertain factors in the shift process, perform chance constraints on the lateral displacement of the synchronizer sleeve.

[0044] The uncertain factors in the shift process include the tooth alignment error and the shift resistance during the shift process.

[0045] The constructed motor transmission includes: a drive motor, a mechanical gearbox, a load motor, two shift actuator motors, sensors, and a servo controller; among them, the mechanical gearbox adopts a configuration of two sets of transmission gears, one shift motor, two sets of shift forks, and two sets of synchronizer sleeves.

[0046] The sensing signal of the shift actuator includes the angle sensor signals of the two shift actuator motors and the position signals of the two sets of synchronizer sleeves;

[0047] The sensing signal of the drive motor includes the torque signal, the speed signal, and the fault signal of the drive motor;

[0048] The load signal includes the speed signal and the torque signal of the wheel hub when simulating the movement of the whole vehicle;

[0049] The driver signal includes the throttle opening;

[0050] The throttle opening can be converted into the torque and gear required by the drive motor according to the automated shift law (to ensure maximum acceleration during power shift, that is, to maximize the torque of the drive motor).

[0051] When the shift actuator motor in the motor transmission uses a brushless DC motor, establish the motor electromagnetic torque equation and the motion equation as:

[0052]

[0053] Among them, is the electromagnetic torque; is the phase current; is the phase voltage; is the mechanical angular velocity; is the mechanical angular acceleration; is the number of pole pairs of the motor; is the magnetic flux linkage of the permanent magnet rotor; is the back electromotive force waveform function of each phase; is the moment of inertia of the motor rotor; is the damping coefficient; is the frictional resistance torque of the motor; is the mechanical load torque of the motor.

[0054] The transmission mechanism of the shift motor includes a planetary reduction mechanism, a two-stage transmission gear set and a shift finger. The planetary reduction mechanism is modeled as:

[0055]

[0056] Among them, is the output torque of the planetary reduction mechanism; T m is the input torque of the planetary reduction mechanism; T sensor represents the additional mechanical load torque introduced by the sensor; is the equivalent moment of inertia of the planetary reduction mechanism; is the damping coefficient of the planetary reduction mechanism; is the output torque of the output shaft; is the equivalent moment of inertia of the output shaft; is the damping coefficient of the output shaft; is the frictional torque of the output shaft; is the reduction ratio of the planetary reduction mechanism; is the transmission efficiency of the planetary reduction mechanism; is the reduction ratio of the two-stage reduction mechanism; is the transmission efficiency of the two-stage reduction mechanism; is the shift resistance; is the effective radius of the shift finger; is the angle of the shift finger. The change in the angle of the shift finger is small, so can be approximated as 1.

[0057] Combined with the shift motor equation, the dynamic equation of the shift actuator is:

[0058]

[0059] Among them:

[0060]

[0061]

[0062] Furthermore, when designing the drive motor, if the drive motor of the motor transmission uses a permanent magnet synchronous motor, the connection between the motor output shaft and the transmission main shaft is regarded as a rigid connection, and the sensor signals are the rotational speed and torque of the permanent magnet synchronous motor output shaft. The permanent magnet synchronous motor is modeled as:

[0063]

[0064] Wherein, is the mechanical angular velocity of the motor; is the sum of the moments of inertia of the input shaft and the transmission; is the damping coefficient, , are the direct-axis and quadrature-axis currents; is the number of pole pairs; are the direct-axis and quadrature-axis inductances; is the motor magnetic flux; is the electromagnetic torque; is the load torque.

[0065] Furthermore, considering the shifting state, the motion equation of the gearbox is:

[0066]

[0067] Wherein, ， is the equivalent moment of inertia and equivalent damping coefficient acting on the motor shaft by the gearbox gears and shafts; is the frictional torque of the motor shaft; is the actual load borne by the gearbox. Under the unloaded state, the load ; is the specified gear ratio; is the transmission efficiency of the specified gear; is the angle of rotation of the gearbox;

[0068] Wherein, the equivalent moment of inertia is:

[0069]

[0070]

[0071] Wherein, is the moment of inertia of the input shaft; is the sum of the moments of inertia of each gear; is the moment of inertia of the output shaft; is the damping coefficient of the input shaft; is the damping coefficient of the two-gear transmission; is the damping coefficient of the driven shaft; are the transmission ratios and transmission efficiencies of each gear; is the position of the engaging sleeve; are the positions of the meshing points of the engaging gear rings of each gear. There are physical limits inside the gearbox to determine the neutral position;

[0072]

[0073]

[0074] Among them, is the moment of inertia of the input shaft; is the sum of the moments of inertia of each gear; is the moment of inertia of the driven shaft; is the damping coefficient of the input shaft; are the damping coefficients of each gear; is the damping coefficient of the driven shaft; is the transmission state function. There are physical limits set inside the gearbox to prevent the two engaging sleeves from being in the engaged state at the same time. The transmission state function satisfies:

[0075]

[0076] Among them, is the transmission ratio function, which satisfies:

[0077]

[0078] Among them, are the transmission ratios and transmission efficiencies of each gear; are the positions of the two engaging sleeves; are the positions of the meshing points of the engaging gear rings of each gear.

[0079] Furthermore, considering the uncertain factors in the shifting process, an opportunity-constrained control method is designed:

[0080]

[0081] Furthermore, considering the compensation of constraint variables, constraint conditions are established

[0082]

[0083]

[0084] Furthermore, the constraint conditions can be expressed as

[0085]

[0086] Among them, are the upper and lower limits of the uncertainty error, which satisfy: .

[0087] Furthermore, considering the computational difficulty, slack variables are introduced for the discrete case and transformed into an equation form.

[0088]

[0089] In summary, based on the upper and lower limits of the uncertain factors during the gear shifting process, the optimization method for the gear shifting process based on chance constraints is designed as follows:

[0090]

[0091] where is the gear shifting torque input; is the gear shifting resistance and tooth alignment error; represents the time / energy consumption required for the gear shifting process; represents the expected position of the shift sleeve after gear shifting; is the expected position of the corresponding gear position; is the permitted error; is the variable compensation for the input according to the uncertain factors is the coefficient matrix; is the upper and lower limits of the uncertainty error; is the introduced slack variable; W is the compensation coefficient matrix.

[0092] Furthermore, during the motor gear shifting control process, the gear shifting control logic is divided into: First, the driver model judges and issues a gear shifting request based on the current speed under the specified stable working condition; Second, the drive motor performs torque unloading control to reduce the impact during the gear shifting process; Then, the original gear shifting motor performs a downshift operation, and drives the shift sleeve to translate to the transmission neutral position range through the chance constraint position controller; In the neutral position, based on the speed ratio of the original gear and the target gear, the speed of the drive motor is adjusted; The target gear shifting motor performs an upshift operation, and drives the shift sleeve to engage with the target gear engaging ring through the chance constraint position controller to the specified gear shift sleeve position range; After the shift sleeve reaches the corresponding position range, the drive motor performs torque recovery control to complete the gear shifting work; Finally, the end position of this upshift, the gear shifting time and the gear shifting energy consumption are substituted into the chance constraint position controller to iteratively correct the control coefficient.

[0093] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0094] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A shift control method for a motor transmission drive system based on chance-constrained programming, characterized in that Including the following steps: Construct a motor transmission and establish a mathematical model of the motor transmission; Collect the operation signals of the shift actuator, the sensing signals of the shift actuator, the sensing signals of the drive motor, and the load signals of the motor transmission; Combine the operation signals of the shift actuator and the sensing signals of the shift actuator to judge the current position and the expected position of the synchronizer sleeve, and design the shift logic of the motor transmission; Based on the driver signal, the sensing signals of the shift actuator, the sensing signals of the drive motor, the load signals, and the shift logic of the motor transmission, during the upshift / downshift process, use the servo controller to control the shift actuator motor to switch between multiple gears; Based on chance constraints, according to the uncertain factors during the shifting process, perform chance constraints on the lateral displacement of the synchronizer sleeve; The uncertain factors during the shifting process include the tooth alignment error and the shifting resistance during the shifting process; Based on the upper and lower limits of the uncertain factors during the shifting process, the optimization method of the shift process based on chance constraints is designed as follows: Among them, is the shift torque input; is the shift resistance and tooth alignment error; represents the time / energy consumption required for the shift process; represents the expected position after the shift sleeve shifts; is the expected position of the corresponding gear; is the permitted error; is the variable compensation for the input according to uncertain factors is the coefficient matrix; are the upper and lower limits of the uncertainty error; is the introduced slack variable; W is the compensation coefficient matrix.

2. The shift control method of the motor transmission drive system based on chance-constrained according to claim 1, characterized in that, The constructed motor transmission includes: a drive motor, a mechanical gearbox, a load motor, two shift actuator motors, sensors, and a servo controller; among them, the mechanical gearbox adopts a configuration of two sets of transmission gears, one shift motor, two sets of shift forks, and two sets of synchronizer sleeves.

3. The shift control method for a motor transmission drive system based on chance-constrained according to claim 2, characterized in that, The sensing signals of the shift actuator include the angle sensor signals of the two shift actuator motors and the position signals of the two sets of synchronizer sleeves; The sensing signals of the drive motor include the torque signal, the speed signal, and the fault signal of the drive motor; The load signals include the speed signal and the torque signal of the wheel hub when simulating the movement of the whole vehicle; The driver signal includes the throttle opening.

4. The shift control method of the motor transmission drive system based on chance-constrained according to claim 3, wherein When the shift actuator motor in the motor transmission uses a brushless DC motor, establish the motor electromagnetic torque equation and the motion equation as follows: Among them, is the electromagnetic torque; is the phase current; is the phase voltage; is the mechanical angular velocity; is the mechanical angular acceleration; is the number of pole pairs of the motor; is the magnetic flux linkage of the permanent magnet rotor; is the back electromotive force waveform function of each item; is the moment of inertia of the motor rotor; is the damping coefficient; is the frictional resistance torque of the motor; is the mechanical load torque of the motor.

5. The shift control method of the motor transmission drive system based on chance-constrained according to claim 4, wherein The transmission mechanism of the shift motor includes a planetary reduction mechanism, a two-stage transmission gear set, and a shift finger. The planetary reduction mechanism is modeled as: Among them, is the output torque of the planetary reduction mechanism; T m is the input torque of the planetary reduction mechanism; T sensor represents the additional mechanical load torque introduced by the sensor; is the equivalent moment of inertia of the planetary reduction mechanism; is the damping coefficient of the planetary reduction mechanism; is the output torque of the output shaft; is the equivalent moment of inertia of the output shaft; is the damping coefficient of the output shaft; is the frictional torque of the output shaft; is the reduction ratio of the planetary reduction mechanism; is the transmission efficiency of the planetary reduction mechanism; is the reduction ratio of the two-stage reduction mechanism; is the transmission efficiency of the two-stage reduction mechanism; is the shifting resistance; is the effective radius of the shifting finger; is the rotation angle of the shifting finger.

6. The shift control method for a motor transmission drive system based on chance-constrained according to claim 1, characterized in that When the drive motor of the motor transmission uses a permanent magnet synchronous motor, the permanent magnet synchronous motor is modeled as: Among them, is the mechanical angular velocity of the motor; is the sum of the moments of inertia of the input shaft and the transmission; is the damping coefficient, , are the direct-axis and quadrature-axis currents; is the number of pole pairs; are the direct-axis and quadrature-axis inductances; is the magnetic flux linkage of the motor; is the electromagnetic torque; is the load torque.

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