Motor transmission driving system gear shifting control method based on chance constraint

Abstract

The invention belongs to the technical field of electric driving gear shifting control, and discloses a motor transmission driving system gear shifting control method based on chance constraint, which comprises the following steps: constructing a motor transmission, and establishing a motor transmission mathematical model; a gear shifting execution mechanism operation signal, a gear shifting execution mechanism sensing signal, a driving motor sensing signal and a load signal of the motor transmission are collected; the current position and the expected position of the joint sleeve are judged by combining the operation signal of the gear shifting execution mechanism and the sensing signal of the gear shifting execution mechanism, and the gear shifting logic of the motor transmission is designed; based on a driver signal, a gear shifting execution mechanism sensing signal, a driving motor sensing signal, a load signal and a motor transmission gear shifting logic; compared with a traditional gear shifting control method, chance constraint is carried out on uncertain factors in the gear shifting process, the gear positioning method for reducing the position precision and enhancing the gear shifting efficiency is designed in combination with the optimization requirement of the gear shifting process, and faster and more efficient motor gear shifting control is achieved.

Description

Technical Field

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

[0002] The motor transmission is a transmission device based on the shift motor driving the clutch sleeve to achieve synchronization between the clutch sleeve and the clutch ring gear, and is an important part of vehicle automation. Conventional shift control includes five stages: torque unloading, shift fork disengagement, speed synchronization, shift fork engagement, and torque recovery. During the shift process and in steady state, accompanied by body vibration, shift resistance, gear position and other uncertain errors, there is a certain displacement deviation between the actual position of the synchronizer and the corresponding gear position, resulting in certain oscillations, prolonged shift time and power interruption, and energy loss.

[0003] In order to solve the above problems, a gear alignment control method has been proposed in recent years. This method actively controls the gear alignment error between the transmission coupling sleeve and the coupling gear ring to improve the success rate of a single gear shift and reduce gear shift impact problems such as gear collision. A variety of gear shift control optimizations combined with modern control methods are proposed to reduce synchronizer oscillation by increasing the dynamic response speed of the gear ring.

[0004] However, the above-mentioned shifting method lacks a constraint process for uncertain errors, and does not solve the synchronizer offset caused by oscillation, which leads to problems such as clutch sleeve wear and energy loss in the vehicle; therefore, there is a problem in the prior art of lacking a method to constrain uncertain factors in the shifting process and optimize the shifting process. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a motor transmission drive system shift control method based on chance constraints, which solves the problem in the prior art of lack of constraints on uncertain factors in the shift process and optimization of the shift process.

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

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

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

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

[0010] Combine the shift actuator operation signal with the shift actuator sensor signal to determine the current position and expected position of the clutch sleeve and design the motor transmission shift logic;

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

[0012] Based on chance constraints, the lateral displacement of the coupling sleeve is constrained according to the uncertain factors in the shifting process.

[0013] The uncertain factors in the gear shifting process include gear alignment error and gear shifting resistance.

[0014] The constructed motor transmission includes: a drive motor, a mechanical gear transmission, a load motor, two shift execution motors, a sensor, and a servo controller; wherein the mechanical gear transmission adopts a configuration of two sets of transmission gears, a shift motor, two sets of shift forks and two sets of coupling sleeves.

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

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

[0017] The load signal includes the rotation speed signal and 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 execution motor in the motor transmission adopts a brushless DC motor, the motor electromagnetic torque equation and motion equation are established as follows:

[0020]

[0021] Among them, T e is the electromagnetic torque; i a ,i b ,i c is the phase current; e a ,e b ,e c is the phase voltage; is the mechanical angular velocity; p is the number of motor poles; ψ m is the permanent magnet rotor flux; f i (θ), i = a, b, c are the waveform functions of each back electromotive force; J m is the moment of inertia of the motor rotor; m is the damping coefficient; T fm is the friction resistance of the motor; T L is the mechanical load torque of the motor.

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

[0023]

[0024] Among them, T p J is the output torque of the planetary reduction mechanism; p is the equivalent moment of inertia of the planetary reduction mechanism; p is the damping coefficient of the planetary reduction mechanism; T s is the output torque of the output shaft; J s is the equivalent moment of inertia of the output shaft; s is the output shaft damping coefficient; T fs is the friction torque of the output shaft; i p is the reduction ratio of the planetary reduction mechanism; η p is the transmission efficiency of the planetary reduction mechanism; i g is the reduction ratio of the secondary reduction mechanism; η g is the transmission efficiency of the secondary reduction mechanism; F L is the gear shift resistance; r f is the effective radius of the shift finger; θ s Point the gearshift lever to the corner.

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

[0026]

[0027] Among them, ω m is the motor mechanical angular velocity; J is the sum of the rotational inertia of the input shaft and the transmission; B is the damping coefficient, i d ,i q is the direct-axis and quadrature-axis current; p n is the pole pair number; L d , L q is the direct-axis and quadrature-axis inductance; ψ f is the motor flux; T e is the electromagnetic torque; T L is the load torque.

[0028] Based on the upper and lower limits of uncertain factors in the gear shifting process, the gear shifting process optimization method based on chance constraints is designed as follows:

[0029]

[0030] Where x is the shift torque input; ε is the shift resistance and tooth error; f(x,ε) represents the time / energy consumption required for the shift process; E(g(x,ε)) represents the expected position of the clutch after shifting; s is the expected position of the corresponding gear; δ is the allowable error; y is the variable compensation for the input based on uncertain factors; A, B, C, D are coefficient matrices; are the upper and lower limits of the uncertainty error; z, z are the introduced slack variables.

[0031] Beneficial effects of the present invention:

[0032] Compared with the traditional gear shifting control method, the method of the present invention takes into account the uncertain factors of gear shifting resistance and tooth error in the gear shifting process, and based on the principle of chance constraint, through the chance constraint of the uncertain factors of the gear shifting process, and combined with the optimization requirements of the gear shifting process, designs a gear positioning method that reduces the position accuracy and enhances the gear shifting efficiency, realizes faster and more efficient motor gear shifting control, minimizes the time and energy loss of the gear shifting process, meets the requirements of gear shifting speed and reliability, and realizes further optimization of the gear shifting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 It 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 opportunity-constrained shift control process of the present invention;

[0036] Figure 3 It is the opportunity constrained shifting principle diagram of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] like Figures 1 to 3 As shown, a shift control method for a motor transmission drive system based on chance constraints comprises the following steps:

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

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

[0041] Combine the shift actuator operation signal with the shift actuator sensor signal to determine the current position and expected position of the clutch sleeve and design the motor transmission shift logic;

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

[0043] Based on chance constraints, the lateral displacement of the coupling sleeve is constrained according to the uncertain factors in the shifting process.

[0044] The uncertain factors in the gear shifting process include gear alignment error and gear shifting resistance.

[0045] The constructed motor transmission includes: a drive motor, a mechanical gear transmission, a load motor, two shift execution motors, a sensor, and a servo controller; wherein the mechanical gear transmission adopts a configuration of two sets of transmission gears, a shift motor, two sets of shift forks and two sets of coupling sleeves.

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

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

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

[0049] Driver signals include throttle opening;

[0050] The throttle opening can be converted into the torque and gear required by the drive motor according to the automated shifting rules (dynamic shifting needs to ensure maximum acceleration, that is, maximum torque of the drive motor).

[0051] When the shift execution motor in the motor transmission adopts a brushless DC motor, the motor electromagnetic torque equation and motion equation are established as follows:

[0052]

[0053] Among them, T e is the electromagnetic torque; i a ,i b ,i cis the phase current; e a ,e b ,e c is the phase voltage; is the mechanical angular velocity; p is the number of motor poles; ψ m is the permanent magnet rotor flux; f i (θ), i = a, b, c are the waveform functions of each back electromotive force; J m is the moment of inertia of the motor rotor; m is the damping coefficient; T fm is the friction resistance of the motor; T L is the mechanical load torque of the motor.

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

[0055]

[0056] Among them, T p J is the output torque of the planetary reduction mechanism; p is the equivalent moment of inertia of the planetary reduction mechanism; p is the damping coefficient of the planetary reduction mechanism; T s is the output torque of the output shaft; J s is the equivalent moment of inertia of the output shaft; s is the output shaft damping coefficient; T fs is the friction torque of the output shaft; i p is the reduction ratio of the planetary reduction mechanism; η p is the transmission efficiency of the planetary reduction mechanism; i g is the reduction ratio of the secondary reduction mechanism; η g is the transmission efficiency of the secondary reduction mechanism; F L is the gear shift resistance; r f is the effective radius of the shift finger; θ s is the shift finger angle. The shift finger angle changes slightly, so cosθ s Can be approximated to 1.

[0057] Combined with the gear shift motor equation, the gear shift actuator dynamics equation is:

[0058] T e =J eq θ m +ζ eq θ m +T feq +F L r f / (i p η p i g η g )

[0059]

[0060]

[0061] Furthermore, the drive motor is designed. When the drive motor of the motor transmission adopts a permanent magnet synchronous motor, the connection between the motor output shaft and the transmission main shaft is regarded as a rigid connection. The sensor signal is the speed and torque of the permanent magnet synchronous motor output shaft. The permanent magnet synchronous motor is modeled as:

[0062]

[0063] Among them, ω m is the motor mechanical angular velocity; J is the sum of the rotational inertia of the input shaft and the transmission; B is the damping coefficient, i d ,i q is the direct-axis and quadrature-axis current; p n is the pole pair number; L d , L q is the direct-axis and quadrature-axis inductance; ψ f is the motor flux; T e is the electromagnetic torque; T L is the load torque.

[0064] Furthermore, considering the gear shifting state, the gearbox motion equation is:

[0065]

[0066] Among them, J sum , sum is the equivalent moment of inertia and equivalent damping coefficient of the gearbox gear and shaft acting on the motor shaft; T fsum is the friction torque of the motor shaft; T L is the actual load on the gearbox. In the unloaded state, the load T L =0;i ref is the specified gear ratio; η ref is the transmission efficiency of the specified gear; θ gb is the gearbox angle;

[0067] Among them, the equivalent moment of inertia is:

[0068]

[0069] Among them, J i is the moment of inertia of the input shaft; J1, J2, is the moment of inertia of each gear; J o is the moment of inertia of the output shaft; iis the input shaft damping coefficient; ζ1,ζ2 are the two gear transmission damping coefficients; ζ o is the damping coefficient of the driven shaft; i n ,η n , i=1, 2 are the transmission ratio and transmission efficiency of each gear, x is the position of the clutch sleeve, x l ,x r For the meshing point position of the ring gear in each gear, there is a physical limit inside the gearbox to determine the neutral position;

[0070]

[0071] Among them, J in is the moment of inertia of the input shaft; J n , n=1,2,3,4 is the sum of the moments of inertia of each gear; J dr is the moment of inertia of the driven shaft; in is the input shaft damping coefficient; ζ n , n=1,2,3,4 are the damping coefficients of each gear; ζ dr is the damping coefficient of the driven shaft; α(x1,x2) is the transmission state function. A physical limit is set inside the gearbox to prevent the two clutches from being in the engagement state at the same time. The transmission state function satisfies:

[0072]

[0073] Among them, β(x1,x2) is the transmission ratio function, which satisfies:

[0074]

[0075] Among them, i n ,η n , i = 1, 2, 3, 4 are the transmission ratios and transmission efficiencies of each gear, x1, x2 are the positions of the two clutch sleeves, x 1l , x 1r ,x 2l ,x 2r The meshing point position of the ring gear for each gear.

[0076] Furthermore, considering the uncertainties in the gear shifting process, a chance-constrained control method is designed:

[0077]

[0078] Furthermore, considering constraint variable compensation, the constraint condition is established

[0079]

[0080] Furthermore, the constraints can be expressed as

[0081]

[0082] Among them, ε max ,ε min are the upper and lower limits of the uncertainty error, satisfying:

[0083] Furthermore, considering the computational difficulty, the discrete case is transformed into an equation by introducing slack variables.

[0084]

[0085] In summary, based on the upper and lower limits of uncertain factors in the gear shifting process, the gear shifting process optimization method based on chance constraints is designed as follows:

[0086]

[0087] Where x is the shift torque input; ε is the shift resistance and tooth error; f(x,ε) is the time / energy required for the shift process; E(g(x,ε)) is the expected position of the clutch after shifting; s is the expected position of the corresponding gear; δ is the allowable error; y is the variable compensation for the input based on uncertain factors; A, B, C, D are coefficient matrices; are the upper and lower limits of uncertainty error; z, is the introduced slack variable.

[0088] Furthermore, in the process of motor shift control, the shift control logic is divided into: first, the driver model judges and issues a shift request based on the current speed under the specified stable working condition; second, the drive motor performs torque unloading control to reduce the impact of the shift process; then, the original gear shift motor performs a downshift operation, and drives the clutch sleeve to translate to the neutral position range of the transmission through the opportunity constraint position controller; in the neutral position, the drive motor speed is adjusted based on the speed ratio between the original gear and the target gear; the target gear shift motor performs a shift operation, and drives the clutch sleeve to engage with the target gear engagement ring through the opportunity constraint position controller to the specified gear clutch position range; after the clutch sleeve reaches the corresponding position range, the drive motor performs torque recovery control to complete the shift; finally, the end position of this shift, the shift time and the shift energy consumption are substituted into the opportunity constraint position controller, and the control coefficient is iteratively corrected.

[0089] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0090] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A shift control method for a motor transmission drive system based on chance constraints, characterized in that: The following steps are involved: Construct a motor transmission and establish a mathematical model of the motor transmission; Collect the shift actuator operation signal of the motor transmission, the shift actuator sensor signal, the drive motor sensor signal and the load signal; Combine the shift actuator operation signal with the shift actuator sensor signal to determine the current position and expected position of the clutch sleeve and design the motor transmission shift logic; Based on the driver signal, the shift actuator sensor signal, the drive motor sensor signal, the load signal and the motor transmission shift logic, during the up / down shift process, the servo controller is used to control the shift actuator motor to switch between multiple gears; Based on chance constraints, the lateral displacement of the coupling sleeve is constrained according to the uncertain factors in the shifting process.

2. The shift control method of the motor transmission drive system based on chance constraints according to claim 1, characterized in that: The uncertain factors in the gear shifting process include gear alignment error and gear shifting resistance.

3. The shift control method of the motor transmission drive system based on chance constraints according to claim 2, characterized in that: The constructed motor transmission includes: a drive motor, a mechanical gear transmission, a load motor, two shift execution motors, a sensor, and a servo controller; wherein the mechanical gear transmission adopts a configuration of two sets of transmission gears, a shift motor, two sets of shift forks and two sets of coupling sleeves.

4. The shift control method of the motor transmission drive system based on chance constraints according to claim 3 is characterized in that: The shift actuator sensor signal includes angle sensor signals of two shift actuator motors and position signals of two sets of engagement sleeves; The drive motor sensor signal includes the torque signal, speed signal and fault signal of the drive motor; The load signal includes the rotation speed signal and torque signal of the wheel hub when simulating the movement of the whole vehicle; The driver signal includes the throttle opening.

5. The shift control method of the motor transmission drive system based on chance constraints according to claim 4, characterized in that: When the shift execution motor in the motor transmission adopts a brushless DC motor, the motor electromagnetic torque equation and motion equation are established as follows: Among them, T e is the electromagnetic torque; i a ,i b ,i c is the phase current; e a ,e b ,e c is the phase voltage; is the mechanical angular velocity; p is the number of motor poles; ψ m is the permanent magnet rotor flux; f i (θ), i = a, b, c are the waveform functions of each back electromotive force; J m is the moment of inertia of the motor rotor; m is the damping coefficient; T fm is the friction resistance of the motor; T L is the mechanical load torque of the motor.

6. The shift control method of the motor transmission drive system based on chance constraints according to claim 5, characterized in that: The transmission mechanism of the shift motor includes a planetary reduction mechanism, a secondary transmission gear set and a shift finger. The planetary reduction mechanism is modeled as: Among them, T p J is the output torque of the planetary reduction mechanism; p is the equivalent moment of inertia of the planetary reduction mechanism; p is the damping coefficient of the planetary reduction mechanism; T s is the output torque of the output shaft; J s is the equivalent moment of inertia of the output shaft; s is the output shaft damping coefficient; T fs is the friction torque of the output shaft; i p is the reduction ratio of the planetary reduction mechanism; η p is the transmission efficiency of the planetary reduction mechanism; i g is the reduction ratio of the secondary reduction mechanism; η g is the transmission efficiency of the secondary reduction mechanism; F L is the gear shift resistance; r f is the effective radius of the shift finger; θ s Point the gearshift lever at the corner.

7. The shift control method of the motor transmission drive system based on chance constraints according to claim 6, characterized in that: When the drive motor of the motor transmission adopts a permanent magnet synchronous motor, the permanent magnet synchronous motor is modeled as: Among them, ω m is the motor mechanical angular velocity; J is the sum of the input shaft and the transmission moment of inertia; B is the damping coefficient, i d ,i q is the direct-axis and quadrature-axis current; p n is the pole pair number; L d , L q is the direct-axis and quadrature-axis inductance; ψ f is the motor flux; T e is the electromagnetic torque; T L is the load torque.

8. The shift control method of the motor transmission drive system based on chance constraints according to claim 7, characterized in that: Based on the upper and lower limits of uncertain factors in the gear shifting process, the gear shifting process optimization method based on chance constraints is designed as follows: Where x is the shift torque input; ε is the shift resistance and tooth error; f(x,ε) represents the time / energy consumption required for the shift process; E(g(x,ε)) represents the expected position of the clutch after shifting; s is the expected position of the corresponding gear; δ is the allowable error; y is the variable compensation for the input based on uncertain factors; A, B, C, D are coefficient matrices; are the upper and lower limits of uncertainty error; z, is the introduced slack variable.

Images