Electric vehicle AMT gear shifting process control simulation method based on Matlab and Adams

Abstract

The invention discloses an electric vehicle AMT gear shifting process control simulation method based on Matlab and Adams. The electric vehicle AMT gear shifting process control simulation method comprises the steps that all parts of an AMT transmission system are established to construct a kinetic model; creating a relationship between parts for the kinetic model, and setting the mass and equivalent rotational inertia of each part according to the mass characteristic of each part; determining an input quantity and an output quantity of the kinetic model; a gear shifting execution mechanism control model is built, and the horizontal movement speed of the combination sleeve is calculated; according to the vehicle kinetic equation of the whole vehicle, the forward running resistance of the vehicle is determined, and the load torque of a first output shaft is calculated; deducing the torque reduction and composite torque rate in the gear shifting process, and calculating the torque of a first input shaft; and inputting the horizontal movement speed of the combination sleeve, the load torque of the first output shaft and the torque of the first input shaft into a model control module, carrying out joint simulation, and analyzing a simulation result. The simulation method provided by the invention greatly retains authenticity and reliability of AMT gear shifting simulation.

Description

Technical Field

[0001] The invention relates to the technical field of automobiles, and in particular to a simulation method for controlling a shifting process of an AMT of an electric vehicle based on Matlab and Adams. Background Art

[0002] New energy vehicles are an important part of the high-quality development of my country's automobile industry. As an important part of new energy vehicles, new energy commercial vehicles will have multiple gears, which is the trend of future development. At present, the AMT shifting process control strategy for pure electric commercial vehicles is in its infancy, and the research on simulation and verification methods for the AMT shifting process of pure electric commercial vehicles is relatively lagging behind.

[0003] First of all, the shifting process of AMT for pure electric commercial vehicles is somewhat different from that of traditional fuel vehicles. The shifting process of AMT for pure electric commercial vehicles can be divided into five parts: torque reduction, gear disengagement, speed regulation, upshifting, and torque recovery. However, the current simulation research on the shifting process only stays in the gear shifting process of traditional fuel vehicles. Most of them use Adams software to simulate the upshifting and gear disengagement processes and analyze indicators such as the required time and impact. This simulation process cannot simulate the complete shifting process. At the same time, this simulation method applies a constant horizontal speed to the coupling sleeve, and cannot simulate the operation of the shifting motor, nor can it simulate the impact of the vehicle's actual driving state on the shifting. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides an electric vehicle AMT shifting process control simulation method based on Matlab and Adams. The method of joint simulation of Matlab and Adams is adopted to build a control module in Matlab to simulate the actual operation of the shift motor and drive the coupling sleeve to move horizontally. At the same time, a vehicle dynamics model is built to simulate the load condition of the vehicle during actual driving, and the torque recovery rate of the drive motor is derived and applied. The influence of the three on the shifting quality is explored to make the simulation process more accurate.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect of the present invention, a method for simulating the shifting process of an AMT of an electric vehicle based on Matlab and Adams is provided, comprising the following steps:

[0007] Establish a dynamic model of the transmission system and set the connection, power and mass relationships between the various components of the model;

[0008] Define state variables based on algebraic equations, determine the input and output of the dynamic model, and generate the model control module;

[0009] Build a shift actuator control model, calculate the mechanical transmission part of the shift actuator, and obtain the horizontal moving speed of the coupling sleeve; determine the forward driving resistance of the vehicle according to the vehicle dynamics equation of the whole vehicle, and obtain the load torque of the first output shaft through the actual load torque calculation model of the first output shaft; derive the torque reduction and recovery rate of the shift process, build a torque reduction and recovery rate limit model, and obtain the first input shaft torque based on the torque reduction and recovery rate limit model;

[0010] The horizontal moving speed of the coupling sleeve, the load torque of the first output shaft and the torque of the first input shaft are input into the model control module to perform joint simulation, and the simulation results are analyzed.

[0011] In some embodiments of the present invention, the establishment of the dynamic model of the transmission system is specifically:

[0012] A three-dimensional model of the input shaft, first gear input gear, second gear input gear, first gear ring gear to be coupled, second gear ring gear to be coupled, output shaft, spline hub, and coupling sleeve of the AMT transmission system was established, and the models of the above components that rotated coaxially and had no relative motion were simplified, that is, the splines of the connecting part of the input shaft, first gear input gear, and second gear input gear were eliminated and simplified into one component, named the first input shaft; the spline hub and output shaft were simplified into the same component, named the first output shaft.

[0013] In some embodiments of the present invention, the connection, power and mass relationship between the components of the model are specifically set as follows:

[0014] Create contacts between the first input shaft and the first gear ring gear to be combined, the first input shaft and the second gear ring gear to be combined, the coupling sleeve and the first gear ring gear to be combined, the coupling sleeve and the second gear ring gear to be combined, and the coupling sleeve and the first output shaft respectively. According to the materials of the parts that contact and collide with each other, input the stiffness, force index, damping, penetration depth, static friction coefficient, dynamic friction coefficient, static translation speed, and friction translation speed parameters between the parts.

[0015] Create connections between components, respectively create a revolute pair of the first input shaft and the first output shaft along their respective axis directions relative to the ground, create a revolute pair of the first gear ring gear to be coupled and the second gear ring gear to be coupled relative to the ground with the axis of the first output shaft as the center line, and the coupling sleeve is set as a cylindrical pair relative to the ground along the axis of the first output shaft;

[0016] Add force and drive to the kinematic pair, add unidirectional torque to the first input shaft and the first output shaft, which are used to represent the driving force output by the drive motor and the driving resistance equivalent to the first output shaft of the vehicle respectively; add translation drive to the combination sleeve, and the direction is fixed in space on the object, which represents the horizontal moving speed of the shift actuator fork head along the axis direction of the first output shaft;

[0017] According to the mass characteristics of each component, the mass and moment of inertia of the first gear ring gear to be combined, the second gear ring gear to be combined, and the coupling sleeve are set, and the mass and equivalent moment of inertia of the first input shaft and the first output shaft are set, wherein the equivalent moment of inertia of the first input shaft is the sum of the moment of inertia of the motor and the moment of inertia of the first input shaft, and the equivalent moment of inertia of the first output shaft is the equivalent moment of inertia of the whole vehicle, wheel hub, half shaft, differential, reducer and first output shaft equivalent to the first output shaft.

[0018] In some embodiments of the present invention, the steps of defining state variables based on algebraic equations, establishing a connection between Adams and Matlab, defining input and output of the dynamic model, implementing Matlab-driven state variables, and generating a model control module are specifically as follows:

[0019] creating state variables defined by algebraic equations, and taking the torques of the first input shaft and the first output shaft and the translational driving speed of the coupling sleeve as inputs of the dynamic model;

[0020] The horizontal displacement of the coupling sleeve, the speed of the first output shaft, the speed of the first gear ring gear to be engaged, the speed of the second gear ring gear to be engaged, the angular acceleration of the first output shaft, and the axial force data of the coupling sleeve are measured, and state variables defined by algebraic equations are created, and the above data are used as the output of the dynamic model.

[0021] In some embodiments of the present invention, the horizontal moving speed of the coupling sleeve, the load torque of the first output shaft, and the torque of the first input shaft are calculated as follows:

[0022] Build a shift actuator control model, calculate the mechanical transmission part of the shift actuator, build a shift motor control model, the output of the shift motor control model is the speed of the motor, and the output of the shift actuator control model is the horizontal moving speed of the coupling sleeve;

[0023] The driving resistance of the vehicle forward is determined according to the vehicle dynamics equation of the whole vehicle, and the output of the gear shift dynamics model is used as feedback to design a first output shaft actual load torque calculation model, wherein the output of the first output shaft actual load torque calculation model is the first output shaft load torque;

[0024] The torque reduction and recovery rate during the gear shifting process is derived, and the output of the gear shifting dynamics model is used as feedback to build a torque reduction and recovery rate limiting model, wherein the output of the torque reduction and recovery rate limiting model is the torque of the first input shaft.

[0025] In some embodiments of the present invention, the shift actuator control model is used to control the shift motor, and the target torque of the shift motor, the target speed of the shift motor, and the gear stage information are input into the shift motor control model to obtain the actual power of the shift motor and the horizontal moving speed of the shift actuator coupling sleeve. The horizontal moving speed of the coupling sleeve is the horizontal moving speed of the shift actuator motor transmitted to the fork head via the mechanical part.

[0026] In some embodiments of the present invention, the shift actuator control model includes a target speed and torque calculation model, a PID control model, a power supply model, an inverter model, and a brushless DC motor model; the input of the PID control model is the difference between the target speed and the actual speed of the shift motor, the target speed of the shift motor is determined by the speed and torque calculation model, the output of the shift motor is the actual speed and torque of the shift motor, and the actual speed of the shift motor is output through the mechanical part of the shift actuator as the input of the model control module combined with the horizontal movement of the sleeve.

[0027] In some embodiments of the present invention, the vehicle dynamics equation is specifically:

[0028] During driving, the vehicle will be subject to the rolling resistance f of the ground and the component force F of the vehicle mass in the direction of gravity. s , air resistance F w , and the acceleration resistance F generated by the acceleration process Δ composition;

[0029] f=μmgcos(θ)

[0030] F s =mgsin(θ)

[0031]

[0032] F w =δma

[0033] Where μ is the rolling resistance coefficient of the vehicle, m is the mass of the vehicle, g is the acceleration of gravity, θ is the ground inclination angle, C D is the air resistance coefficient, A is the windward area, and ρ is the air density, which is about 1.209 kg / m 3 , V is the vehicle's speed, δ is the rotational mass conversion factor, and a is the vehicle's acceleration;

[0034]

[0035] Among them J cl is the moment of inertia of a single wheel, J f is the moment of inertia of the engine flywheel, η tis the transmission efficiency of the transmission system, and the conversion factor δ for the rotational mass of the first and second gears 1 and δ 2 Perform the calculation:

[0036]

[0037]

[0038] Among them, J jht is the moment of inertia of the coupling sleeve, η is the transmission efficiency of mechanical transmission, J 1d is the moment of inertia of the gear ring to be engaged in the first gear, J 2d is the moment of inertia of the second gear ring gear to be engaged, i 1 is the speed ratio of the first gear, i 2 is the speed ratio of the second gear;

[0039] The total external load force of the vehicle in the first and second gear states is F s1 and F s2 The relationship is:

[0040]

[0041]

[0042] According to the operating characteristics of the drive motor, combined with the relationship between the output torque and the load, the actual dynamic equation of the vehicle is derived as follows:

[0043] The dynamic equations of a vehicle in one gear are:

[0044]

[0045] The dynamic equations of a vehicle in second gear,

[0046]

[0047] Where α is the output ratio of the rated torque, T is the rated torque of the motor, n is the actual speed of the motor, and n 0 is the rated speed of the motor, and P is the rated power of the motor.

[0048] In some embodiments of the present invention, the current speed of the vehicle, gear information, and the output torque of the drive motor are input into the actual load torque calculation model of the first output shaft for calculation, so as to obtain the first output shaft resistance torque and the equivalent starting torque to be overcome on the first output shaft;

[0049] When the input torque of the drive motor is less than the starting torque, the first output shaft load torque is the torque output by the drive motor to the first input shaft; when the input torque of the drive motor is greater than the starting torque, the first output shaft load torque is the first output shaft resistance torque.

[0050] In some embodiments of the present invention, the derivation of the torque reduction and recovery rate during the gear shifting process is specifically:

[0051] When the vehicle acceleration is greater than 0, the actual output torque T can be obtained from the vehicle dynamics equation of the whole vehicle. r Relationship with road load:

[0052]

[0053]

[0054]

[0055] The entire shifting process takes a very short time. The speed change and the road inclination angle can be ignored and regarded as constants. Only the torque change rate T needs to be considered. r changes;

[0056]

[0057]

[0058] According to the impact requirement j≤10m / s 3

[0059] The ranges of the torque reduction and torque recovery rates for the first and second gears are as follows:

[0060]

[0061]

[0062] When the vehicle acceleration is less than 0, the torque change rate range is:

[0063]

[0064]

[0065] One or more technical solutions of the present invention have the following beneficial effects:

[0066] The present invention proposes a joint simulation method for the gear shifting process based on Matlab and Adams, in which a control model is built in Matlab and a mechanical transmission model is built in Adams. The joint simulation method can realize the simulation of the complete gear shifting process, the simulation of the actual operation of the gear shifting actuator, and the simulation of gear shifting under different driving conditions of the vehicle, which greatly retains the authenticity and reliability of the gear shifting simulation and also provides a feasible method for the subsequent research on the gear shifting quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 This is a schematic diagram of the structure of the transmission part of the electric drive powertrain of a commercial vehicle provided in Example 1 of the present invention;

[0068] Figure 2 The Adams mechanical structure model diagram provided in Example 1 of the present invention;

[0069] Figure 3 A flow chart of a shifting process joint simulation method based on Matlab and Adams provided in Example 1 of the present invention;

[0070] Figure 4 A Matlab and Adams information transmission relationship diagram of a shift process joint simulation method based on Matlab and Adams provided in Example 1 of the present invention;

[0071] Figure 5 A structural diagram of a control part of a joint simulation model of a shifting process joint simulation method based on Matlab and Adams provided in Example 1 of the present invention;

[0072] Figure 6 A diagram of a gear switching judgment module of a gear shifting process joint simulation method based on Matlab and Adams provided in Example 1 of the present invention;

[0073] Figure 7 It is a stateflow logic diagram inside the chart in the gear switching judgment module provided in the first embodiment of the present invention;

[0074] Figure 8 A schematic diagram of a gear shift curve of the gear switching judgment module provided in Example 1 of the present invention;

[0075] Fig. 9 A schematic diagram of a target speed and target torque calculation and output module provided in Embodiment 1 of the present invention;

[0076] Fig.10 A schematic diagram of a target torque and speed calculation module provided in Embodiment 1 of the present invention;

[0077] Fig.11 A control principle diagram of a shift actuator provided in Example 1 of the present invention;

[0078] Fig.12 A control model diagram of a shift motor provided in Example 1 of the present invention;

[0079] Fig.13 A diagram of a first output shaft load calculation model provided in Example 1 of the present invention;

[0080] Fig.14The torque reduction and recovery rate limiting simulink model provided in Example 1 of the present invention;

[0081] Fig.15 This is a diagram of a three-speed torque control module provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0082] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0083] Example 1

[0084] First of all, it should be made clear that the transmission structure of the commercial vehicle electric drive powertrain is as follows: Figure 1 As shown:

[0085] The first part includes the driving motor output driving force; the second part is the AMT gearbox, the gearbox input shaft is fixed with the first gear and the second gear, the first gear and the second gear are always meshed with the first gear ring gear to be engaged and the second gear ring gear to be engaged, the first gear ring gear to be engaged and the second gear ring gear to be engaged are loosely sleeved on the gearbox output shaft, the engaging sleeve is sleeved on the spline hub, and can be driven by the shift actuator to move horizontally along the output shaft axis direction, the spline hub is fixed on the output shaft, and the gearbox output shaft is connected to the main reducer input gear; the third part is the main reducer, the main reducer 3 output gear is connected to the main reducer 3; the fourth part is the differential, its output gear is connected to the vehicle half shaft; the fifth part is the wheel hub.

[0086] The power transmission route is that the driving motor outputs power to the gearbox, the input shaft transmits power to the first and second gear ring gears through the first and second gears, the ring gear to be coupled transmits power to the spline hub through the coupling sleeve, and then to the output shaft of the gearbox, and finally the power is transmitted to the main reducer, differential, half shaft, and wheel hub in sequence. The present invention mainly provides a joint simulation verification method for the shifting process of the AMT gearbox 2.

[0087] In a typical embodiment of the present invention, a simulation method for controlling the shifting process of an AMT of an electric vehicle based on Matlab and Adams is proposed, comprising:

[0088] Step 1: According to the structural dimensions of the AMT gearbox 2, create a three-dimensional model of the AMT gearbox input shaft, first gear input gear, second gear input gear, first gear ring gear to be combined, second gear ring gear to be combined, output shaft, spline hub, and coupling sleeve in the solidworks software.

[0089] Step 2: Simplify the models of components that rotate coaxially and have no relative motion, eliminate the splines of the connection parts of the input shaft, the first gear input gear, and the second gear input gear, and simplify them into one component; simplify the spline hub output shaft into the same component, named the first input shaft and the first output shaft respectively. Assemble the components to form an assembly, and save the assembly file as .x_t format.

[0090] Step 3: Open the Adams software and import the .x_t assembly file in step 1. The Adams mechanical model is as follows: Figure 2 shown.

[0091] Step 4: Click the special force contact creation option in the Adams software to create the contact between the first input shaft and the first gear ring gear to be combined, the first input shaft and the second gear ring gear to be combined, the combination sleeve and the first gear ring gear to be combined, the combination sleeve and the second gear ring gear to be combined, and the combination sleeve and the first output shaft. According to the materials of the parts that contact and collide with each other, input the stiffness, force index, damping, penetration depth, static friction coefficient, dynamic friction coefficient, static translation speed, friction translation speed and other parameters between the parts. In this embodiment, carburized steel 20CrMnTi is selected as the material of the parts. It is a collision between steel and steel in the presence of lubricating oil. The values ​​of each parameter are, 1.5,, 0.1, 0.08, 0.05, 0.1, 10, respectively. The parameters are input into the created constraints.

[0092] Step 5: Create connections between components. Create rotation pairs for the first input shaft and the first output shaft along their respective axial directions relative to the ground. Create rotation pairs for the first gear ring gear and the second gear ring gear to be combined relative to the ground with the first output shaft axis as the center line. The coupling sleeve is set as a cylindrical pair relative to the ground along the first output shaft axis direction.

[0093] Step 6: Add force and drive to the kinematic pair, add unidirectional torque to the first input shaft and the first output shaft, which are respectively used to represent the driving force output by the drive motor and the driving resistance of the vehicle equivalent to the first output shaft; add translational drive to the combination sleeve, and the direction is selected to be fixed in space on the object, representing the horizontal movement speed of the shift actuator fork head along the axis of the first output shaft.

[0094] Step 7: According to the mass characteristics of each component, set the mass and moment of inertia of the first gear ring gear to be combined, the second gear ring gear to be combined, and the coupling sleeve, and set the mass and equivalent moment of inertia of the first input shaft and the first output shaft, where the equivalent moment of inertia of the first input shaft is the sum of the moment of inertia of the motor and the moment of inertia of the first input shaft, and the equivalent moment of inertia of the first output shaft is the equivalent moment of inertia of the whole vehicle, wheel hub, half shaft, differential, reducer and first output shaft equivalent to the first output shaft.

[0095] In the above calculation method of equivalent rotational inertia, the equivalent rotational inertia calculation method based on the law of conservation of energy is adopted, and the friction loss of the transmission system and other issues affecting efficiency are ignored. The analysis and calculation process is as follows:

[0096] By Figure 2 It can be seen from the structure of the AMT gearbox 2 shown that the first gear ring gear to be engaged and the second gear ring gear to be engaged are loosely sleeved on the output shaft and are constantly meshed with the first input shaft. The spline hub is fixed on the first output shaft, the coupling sleeve is sleeved on the spline hub, and the first output shaft is connected to the main reducer, the differential and the wheel hub in sequence. The equivalent moment of inertia of the first input shaft is the sum of the moment of inertia of the drive motor connected thereto and the moment of inertia of the first input shaft:

[0097]

[0098] Among them, E in is the total work of the input part, J in1 is the equivalent moment of inertia of the first input shaft, ω in1 is the angular velocity of the first input shaft, J dj is the moment of inertia of the motor, ω dj is the angular velocity of the motor, J inz is the moment of inertia of the input shaft

[0099] where ω in1 and ω dj The coaxial rotation is equal, then the equivalent moment of inertia of the first input shaft is J in1 for:

[0100] J in1 =J dj +J inz

[0101] Analysis of the first output shaft shows that the equivalent moment of inertia of the first output shaft is the sum of the equivalent moment of inertia of the coupling sleeve, main reducer, differential, half shaft, wheel, and vehicle mass connected to it and the moment of inertia of the first output shaft. According to the law of conservation of energy, the following formula can be obtained:

[0102]

[0103] Among them, E out is the total work of the input part, J out is the equivalent moment of inertia of the first output shaft, ω out is the equivalent angular velocity of the first output shaft, J jht is the moment of inertia of the coupling sleeve, ω jht is the angular velocity of the coupling sleeve, J outz is the moment of inertia of the first output shaft and the input gear of the final reducer, J zjis the moment of inertia of the main reducer output gear, ω zj is the actual angular velocity of the main reducer, J cs is the moment of inertia of the differential input part, ω cs is the actual angular velocity of the differential input, J bz is the moment of inertia of the differential output part and the half shaft, ω bz is the actual angular velocity of the differential output part and the half shaft, J cl is the sum of the moments of inertia of individual wheels, ω cl is the actual angular velocity of the wheel, m is the vehicle mass, and V is the actual speed of the vehicle.

[0104] According to the transmission relationship of the transmission system, the angular velocity relationship of each component can be derived as follows:

[0105] ω out =ω jht =ω outz =ω zj i 3 =ω cs i 3 =ω bz i 3 i 4 =ω cl i 3 i 4

[0106] where i 3 is the reduction ratio of the main reducer, i 3 is the differential speed ratio, the actual speed V of the vehicle and the angular velocity ω of the wheel cl and the equivalent angular velocity of the spline hub ω out The relationship is:

[0107] V=ω cl R

[0108]

[0109] Then the equivalent moment of inertia of the first output shaft J out for:

[0110]

[0111] The calculated J out and J in1 The value is brought into step 7.

[0112] Step 8: Create state variables defined by algebraic equations, establish the connection between Adams and Matlab, define the input and output of the dynamic model, and use the torque of the first input shaft and the first output shaft and the moving speed of the coupling sleeve in step 6 as Adams input.

[0113] Step 9: Measure the horizontal displacement of the coupling sleeve, the speed of the first output shaft, the speed of the first gear ring gear to be engaged, the speed of the second gear ring gear to be engaged, the angular acceleration of the first output shaft, and the axial force data of the coupling sleeve, and create state variables defined by algebraic equations, establish the connection between Adams and Matlab, and use the above data as output.

[0114] Step 10: In the mechanical system export part of the Adams control module in the motor plug-in, select the Adams input in step 8 for the mechanical system input, select the Adams output in step 9 for the mechanical system output, select Matlab as the target software, select nonlinear as the analysis type, select C++ as the Adams solver, and click OK.

[0115] Step 11: Set the starting position of Matlab software to the folder where Adams software is located, use Matlab software to run the .m file generated in step 10, enter Adams_sys and click Run to generate Adams_sub module.

[0116] Step 12: Process the generated output of the Adams_sub module, unify the output speed into revolutions per minute, and feed the output signal back to the input for calculation of the input signal.

[0117] Step 13: Build a shift actuator control model, calculate the mechanical transmission part of the shift actuator, build a shift motor PID control model, and the model output is the horizontal moving speed of the combination sleeve.

[0118] Step 14: Determine the vehicle's forward driving resistance based on the vehicle dynamics equation, use the Adams model output as feedback, and design a simulink model for calculating the actual load torque on the first output shaft. The model output is the load torque of the first output shaft.

[0119] Step 15: Derive the torque reduction and recovery rate during the gear shifting process, use the Adams model output as feedback, build a simulink model, and the model output is the first input shaft torque.

[0120] Step 16: Set the Adams solver, select C++ as the solver type, select interactive as the animation mode, select discrete as the simulation mode, set the communication time interval. The smaller the time interval, the more accurate the calculation. The larger the calculation amount, the longer the time consumption. The communication time interval of the present invention is set to 0.001. Select interactive joint simulation mode to carry out joint simulation, and analyze the simulation results.

[0121] In this embodiment, the simulink model construction and key parameter calculation method are specifically as follows:

[0122] like Figure 5 As shown, the simulink model in steps 12 to 16 is divided into the following parts, where the first part is the Adams_sub module used to connect the Adams mechanical model and the simulink control model;

[0123] The second part is the Adams signal post-processing module. The signals A, I, L, B, G, C, and D output by the post-processing module represent the position information of the coupling sleeve, the speed of the first output shaft, the vehicle's driving speed, the speed of the first gear ring gear to be engaged, the information of the completion of the speed regulation of the first gear, the speed of the second gear ring gear to be engaged, and the shifting force on the coupling sleeve, which are used as the input of the simulink control model.

[0124] The third part is the gear shift judgment module, which is used to judge whether to start shifting at different accelerator pedal openings and vehicle speeds, and to feedback the current gear position and the stage of the gear shift;

[0125] The fourth part is the gear shift random delay module, which generates a random number for delay through Matlab, which can be used to simulate the response time of the controller and ensure the randomness of the collision between the coupling sleeve and the gear ring to be coupled during the upshift process, ensuring the rationality of the simulation;

[0126] The fifth part is the horizontal moving speed input of the coupling sleeve, and the horizontal moving speed of the shift actuator fork head is used as the horizontal moving speed of the coupling sleeve;

[0127] Part 6 is the first input shaft torque input module, which limits the torque change rate during the torque reduction and re-torque process;

[0128] Part 7 is the first output shaft load torque input module, which determines the load torque provided by the vehicle running on the first output shaft by calculating the vehicle's dynamic equation.

[0129] According to the calculation difficulty of each part and the complexity of model building, this embodiment describes parts 3, 5, 6 and 7 in detail.

[0130] (1) In the joint simulation method of the AMT shifting process of pure electric commercial vehicles based on Matlab and Adams, the detailed model diagram of the third part of the gear shift judgment module is as follows: Figure 6 As shown in the figure, the input x of this module is the vehicle speed, y is the accelerator pedal opening, and the corresponding gear information is determined by calculating different vehicle speeds and different pedal openings. Gear is the output gear signal information, and shift is the gear shifting stage. The internal logic diagram of the chart is as follows Figure 7As shown, the basic content is Figure 8 The shift curve shown in the figure shows that the green line is the upshift curve and the red line is the downshift curve. During the gear switching process, the shift output logic is: shifting from neutral to one gear is 1, shifting from first gear to neutral is 2, shifting from first gear to second gear is 3, and shifting from second gear to one gear is 4. The output is used to calculate the input of Adams_sub.

[0131] (2) In the joint simulation method of the AMT shifting process of pure electric commercial vehicles based on Matlab and Adams, the detailed process of the shifting actuator control model in step 13 is as follows:

[0132] Traditional shift actuators mainly include three types: electronically controlled-electric, electronically controlled-pneumatic, and electronically controlled-hydraulic. The present invention takes the electronically controlled-electric shift actuator as an example, takes the shift motor speed as input, transmits it through the mechanical transmission part, and outputs the motor speed as the horizontal moving speed of the shift fork.

[0133] The present invention uses a brushless DC motor with a voltage of 24V, a power of 200W, a current of 20A, a speed of 1200rpm, and a torque of 1.6Nm as a shift motor. The target torque of the motor is the load torque transmitted to the shift motor by the resultant force in the axial direction of the coupling sleeve in step 9 through the mechanical part. When the power of the motor is less than 200W, the target speed of the motor is 1200rpm. When the output power of the motor is greater than 200W, the target speed of the motor is the ratio of power to actual load. The construction of its simulink model is as follows: Fig. 9 shown.

[0134] The first part is the module input, which mainly includes the lateral force on the coupling sleeve, the position information of the coupling sleeve, the actual power of the shift motor, the shift start signal after the delay, the shift stage position information, the first gear up to second gear speed regulation completion signal and the second gear down to one gear speed regulation completion signal. The second part is the shift execution motor target torque and target speed calculation module. According to the movement form of the shift motor, the present invention divides the calculation process into four parts: first gear up, first gear disengagement, second gear up, and second gear disengagement, and calculates the target speed torque at different stages respectively. The third part is to screen the target speed torque according to the stage of the shift. The fourth part is the output module, which inputs the target speed and target torque into the motor control module.

[0135] Taking the calculation of the first gear as an example, the simulink model of the second part of the target speed and target torque calculation module is as follows Fig.10As shown in the figure, the first part is the module input, the second part is the target torque calculation module, combined with the shift resistance of the sleeve, the load torque transmitted to the shift motor through the mechanical part of the shift actuator, represented by Matlab function, the target value is less than 1.6N·m, the third part is the target speed calculation module, the target value is less than 1200rpm. The rest is similar to the first gear up model.

[0136] like Fig.11 As shown in the figure, the shift actuator control model is mainly for the control of the shift motor, including the target speed torque calculation model, PID control model, power supply model, inverter model and brushless DC motor model. The motor control model is controlled by a PID controller. The input of the PID controller is the difference between the target speed and the actual speed of the motor, where the target speed of the motor is determined by the speed torque calculation module. The output of the motor is the actual speed and torque of the motor, where the actual speed of the motor is output through the mechanical part of the shift actuator as the input of the horizontal movement of the Adams_sub combination sleeve.

[0137] Depend on Fig.12 It can be seen from the simulink control model diagram of the gear shift motor that the input quantities in the diagram correspond to the target torque of the gear shift motor, the target speed of the gear shift motor, and the gear stage information respectively; the output quantity is the actual power of the gear shift motor and the horizontal moving speed of the gear shift actuator sleeve. The horizontal moving speed of the sleeve is the horizontal moving speed of the gear shift actuator motor transmitted to the fork head through the mechanical part. The mechanical part is described in the form of Matlab function. Different mechanical structure formulas are derived differently. The present invention does not describe the mechanical structure derivation in detail for the time being.

[0138] The power system model environment module selects discrete, the sampling time is, the power module selects direct current, and the voltage is 24V. The shift motor adopts PID control. The motor module order selects 3rd order, and the waveform selects trapezoidal wave. The input of the shift motor is the target torque and the three-phase currents A, B, and C. The output is the actual speed, torque, and Hall signal output by the Hall sensor of the motor. The actual speed of the motor is used to calculate the horizontal movement speed of the fork through the mechanical part of the shift actuator, and the actual power of the motor is calculated with the actual torque. The Hall signal output by the Hall sensor is calculated to control the switch of the inverter current.

[0139] (3) In the joint simulation method of the AMT shifting process of pure electric commercial vehicles based on Matlab and Adams, the calculation method of the vehicle dynamics equation in step 14 is as follows:

[0140] During driving, the vehicle will be subject to the rolling resistance f of the ground and the component force F of the vehicle mass in the direction of gravity. s , air resistance Fw , and the acceleration resistance F generated by the acceleration process Δ composition.

[0141] f=μmgcos(θ)

[0142] F s =mgsin(θ)

[0143]

[0144] F w =δma

[0145] Where μ is the rolling resistance coefficient of the vehicle, m is the mass of the vehicle, g is the acceleration of gravity, θ is the ground inclination angle, C D is the air resistance coefficient, A is the frontal area, ρ is the air density about 1.209kg / m3, V is the vehicle speed, δ is the rotational mass conversion coefficient, a is the vehicle acceleration, according to the formula.

[0146]

[0147] Among them J cl is the moment of inertia of a single wheel, J f is the moment of inertia of the engine flywheel, η t The transmission efficiency of the transmission system. For pure electric vehicles, there is no flywheel energy storage device. Gu only needs to calculate the rotational inertia of each component in the transmission system, among which the rotational mass conversion coefficient δ of the first and second gears is 1 and δ 2 Respectively.

[0148]

[0149]

[0150] Among them, J jht is the moment of inertia of the coupling sleeve, η is the transmission efficiency of mechanical transmission, J 1d is the moment of inertia of the gear ring to be engaged in the first gear, J 2d is the moment of inertia of the second gear ring gear to be engaged, i 1 is the speed ratio of the first gear, i 2 The speed ratio for second gear.

[0151] It can be concluded that the total external load force of the vehicle in the first and second gear states is F s1 and F s2 The relationship

[0152]

[0153]

[0154] According to the operating characteristics of the drive motor and the relationship between the output torque and the load, the actual dynamic equation of the vehicle is derived:

[0155] The equation of motion for a vehicle in 1 gear,

[0156]

[0157] The equation of motion for a 2-gear vehicle,

[0158]

[0159] Where α is the output ratio of the rated torque, T is the rated torque of the motor, n is the actual speed of the motor, and n 0 is the rated speed of the motor, and P is the rated power of the motor.

[0160] Knowing μ, g, C in the vehicle dynamics equations for 1st and 2nd gears D ,A,R,i 1 、i 3 All are known quantities, m, θ, V, δ 1 ,δ 2 and a are unknown quantities, where m is determined by the actual mass of the vehicle, V and a are determined by the speed of the first output shaft derived from the Adams_sub output signal, and δ 1 and δ 2 Calculated according to the above formula. According to the vehicle dynamics equation, the first output shaft load calculation program is built in Matlab / simulink as follows Fig.13 shown.

[0161] The first part is the input, which mainly includes the vehicle's current speed, gear information, and the output torque of the drive motor. The second part is the calculation module of the vehicle dynamics equation, where the output F is the resistance torque on the first output shaft of the vehicle, and the output F0 is the starting torque that needs to be overcome on the first output shaft. The third part is the rotational mass conversion coefficient δ 1 and δ 2 The calculation module of the first output shaft load torque output module is shown in the figure. When the input torque of the drive motor is less than the starting torque, the resistance torque value of the first output shaft is the torque output by the drive motor to the first input shaft. When the input torque of the drive motor is greater than the starting torque, the output is the resistance torque of the first output shaft in step 2.

[0162] (4) In the joint simulation method of the AMT shifting process of pure electric commercial vehicles based on Matlab and Adams, the torque reduction and recovery rate in step 15 is one of the main factors causing the shifting shock. The shifting shock refers to the derivative of the change of vehicle acceleration during the shifting process. Combined with the derivation of the vehicle dynamics equation in step 14, the relationship between the torque recovery rate and the shifting process shock is derived.

[0163] According to the acceleration and deceleration states of the vehicle's gear shifting process, the research on the impact of gear shifting on torque reduction and torque recovery rate can be roughly divided into gear shifting when the vehicle is in the acceleration stage and gear shifting when the vehicle is in the acceleration stage.

[0164] The shifting process of AMT is non-powered shifting. There is a power interruption during the shifting process. When the power is completely interrupted, the vehicle is only subject to driving resistance. When the vehicle is shifting in the acceleration stage, the vehicle acceleration is first positive and then negative in the torque reduction stage, and the vehicle acceleration is first negative and then positive in the torque recovery stage. When the vehicle is shifting in the acceleration stage, the vehicle acceleration is always negative.

[0165] When the vehicle's acceleration is positive, the drive motor outputs driving force. At this time, the motor outputs power to drive the vehicle forward. The power transmission route is drive motor → transmission system → wheel hub. When the vehicle's acceleration is negative, the external driving resistance is transmitted to the motor through the transmission system, dragging the drive motor to decelerate. The power transmission route is wheel hub → transmission system → drive motor.

[0166] When the vehicle acceleration is greater than 0, the actual output torque T r Relationship with road load.

[0167]

[0168]

[0169]

[0170] The entire shifting process takes a very short time. The speed change and the road inclination angle are negligible and can be regarded as constants. Only the torque change rate T needs to be considered. r changes.

[0171] Right now

[0172]

[0173]

[0174] According to the impact requirement j≤10m / s 3

[0175] It can be concluded that the ranges of the torque reduction and torque recovery rates for the first and second gears are

[0176]

[0177]

[0178] Similarly, when the vehicle acceleration is less than 0, the torque change rate range is

[0179]

[0180]

[0181] Since η is less than or equal to 0 Therefore, the torque change rate should be the torque change rate when the acceleration is less than 0. Since the change of acceleration during the gear shifting process is extremely complex, the present invention selects the minimum value of the torque change rate when the two accelerations are less than 0 as the limit of the output torque of the drive motor.

[0182] Fig.14 This is the simulink model for torque reduction and recovery rate limitation in step 15. The first part is the module input, the second part is the shift process control module, the third part is the torque minimum change slope calculation module, and the fourth part is the first input shaft torque input module. The slope calculated in the third part is used for torque slope control in the fourth part after size comparison.

[0183] Taking the first gear to the second gear as an example, the simulink diagram of the drive motor torque control model is as follows Fig.15 As shown, the first part is the input quantity, which is the position information of the coupling sleeve, the pedal opening, the speed of the second gear ring gear to be engaged, the actual speed of the spline hub, and the gear shifting stage information. The second part is the speed difference judgment module between the ring gear to be engaged and the spline hub. When the output value of the gear information is 3 and the speed difference between the two is less than 50rpm, the output is a value of 1. The third part is the speed regulation module of the first input shaft, which is used to reduce the speed difference between the first output shaft and the second gear ring gear to be engaged. The fourth part is used to determine whether the coupling sleeve is in the neutral position and whether the neutral speed regulation conditions are met. In the fifth part, when the coupling sleeve reaches the second gear position, the torque output is restored.

[0184] The traditional Adams-based gear shift simulation cannot achieve accurate simulation of the gear shift process. The present invention adopts the Adams and Matlab joint simulation method to build a gear shift control module in Matlab, and can realize the complete gear shift process simulation in Adams; at the same time, it is different from the traditional Adams gear shift simulation method that sets the horizontal speed of the coupling sleeve to a constant value. The joint simulation method is used to build a gear shift actuator model in Matlab, and the horizontal speed output by the gear shift actuator is used as the horizontal speed of the coupling sleeve. It is also different from the traditional Adams gear shift simulation method that gives a constant torque to the first output shaft. The joint simulation method is used to build the whole vehicle dynamics equation in Matlab, and the real external load is input to the output shaft 1, which greatly retains the authenticity and reliability of the gear shift simulation, and through theoretical calculation, the torque recovery process of the drive motor is calculated and simulated to improve the accuracy of the simulation.

[0185] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A simulation method for electric vehicle AMT shifting process control based on Matlab and Adams, characterized in that: The following steps are involved: Establish the dynamics model of the AMT transmission system and set the connection, power and mass relationships between the various components of the model; Define state variables based on algebraic equations, determine the input and output of the dynamic model, implement Matlab-driven state variables, and generate model control modules; Build a shift actuator control model, calculate the mechanical transmission part of the shift actuator, and obtain the horizontal moving speed of the coupling sleeve; determine the forward driving resistance of the vehicle according to the vehicle dynamics equation of the whole vehicle, and obtain the load torque of the first output shaft through the actual load torque calculation model of the first output shaft; derive the torque reduction and recovery rate of the shift process, build a torque reduction and recovery rate limit model, and obtain the first input shaft torque based on the torque reduction and recovery rate limit model; The horizontal moving speed of the coupling sleeve, the load torque of the first output shaft and the torque of the first input shaft are input into the model control module to perform joint simulation, and the simulation results are analyzed.

2. The electric vehicle AMT shifting process control simulation method based on Matlab and Adams as claimed in claim 1, characterized in that: The specific method of establishing the dynamic model of the transmission system is as follows: A three-dimensional model of the input shaft, first gear input gear, second gear input gear, first gear ring gear to be coupled, second gear ring gear to be coupled, output shaft, spline hub, and coupling sleeve of the AMT transmission system was established, and the models of the above components that rotated coaxially and had no relative motion were simplified, that is, the splines of the connecting part of the input shaft, first gear input gear, and second gear input gear were eliminated and simplified into one component, named the first input shaft; the spline hub and output shaft were simplified into the same component, named the first output shaft.

3. The electric vehicle AMT shifting process control simulation method based on Matlab and Adams as claimed in claim 2, characterized in that: The connection, drive, force and mass relationship between the various parts of the model are specifically set as follows: Create contacts between the first input shaft and the first gear ring gear to be combined, the first input shaft and the second gear ring gear to be combined, the coupling sleeve and the first gear ring gear to be combined, the coupling sleeve and the second gear ring gear to be combined, and the coupling sleeve and the first output shaft respectively. According to the materials of the parts that contact and collide with each other, input the stiffness, force index, damping, penetration depth, static friction coefficient, dynamic friction coefficient, static translation speed, and friction translation speed parameters between the parts. Create connections between components, respectively create a revolute pair of the first input shaft and the first output shaft along their respective axis directions relative to the ground, create a revolute pair of the first gear ring gear to be coupled and the second gear ring gear to be coupled relative to the ground with the axis of the first output shaft as the center line, and the coupling sleeve is set as a cylindrical pair relative to the ground along the axis of the first output shaft; Add force and drive to the kinematic pair, add unidirectional torque to the first input shaft and the first output shaft, which are used to represent the driving force output by the drive motor and the driving resistance equivalent to the first output shaft of the vehicle respectively; add translation drive to the combination sleeve, and the direction is fixed in space on the object, which represents the horizontal moving speed of the shift actuator fork head along the axis direction of the first output shaft; According to the mass characteristics of each component, the mass and moment of inertia of the first gear ring gear to be combined, the second gear ring gear to be combined, and the coupling sleeve are set, and the mass and equivalent moment of inertia of the first input shaft and the first output shaft are set, wherein the equivalent moment of inertia of the first input shaft is the sum of the moment of inertia of the motor and the moment of inertia of the first input shaft, and the equivalent moment of inertia of the first output shaft is the equivalent moment of inertia of the whole vehicle, wheel hub, half shaft, differential, reducer and first output shaft equivalent to the first output shaft.

4. The electric vehicle AMT shifting process control simulation method based on Matlab and Adams as claimed in claim 3, characterized in that: The method of defining state variables based on algebraic equations, determining the input and output of the dynamic model, and generating the model control module is specifically as follows: Create state variables defined by algebraic equations, establish the connection between Adams and Matlab, and use the torque of the first input shaft and the first output shaft and the translational driving speed of the coupling sleeve as the input of the dynamic model, and drive the input by Matlab; The horizontal displacement of the coupling sleeve, the speed of the first output shaft, the speed of the first gear ring gear to be engaged, the speed of the second gear ring gear to be engaged, the angular acceleration of the first output shaft, and the axial force data of the coupling sleeve are measured, and state variables defined by algebraic equations are created. The connection between Adams and Matlab is established, and the above data is used as the output of the dynamic model for data processing by Matlab.

5. The electric vehicle AMT shifting process control simulation method based on Matlab and Adams as claimed in claim 1, characterized in that: The calculated horizontal moving speed of the coupling sleeve, the load torque of the first output shaft and the torque of the first input shaft are specifically: Build a shift actuator control model, calculate the mechanical transmission part of the shift actuator, build a shift motor control model, the output of the shift motor control model is the speed of the motor, and the output of the shift actuator control model is the horizontal moving speed of the coupling sleeve; The driving resistance of the vehicle forward is determined according to the vehicle dynamics equation of the whole vehicle, and the output of the gear shift dynamics model is used as feedback to design a first output shaft actual load torque calculation model, wherein the output of the first output shaft actual load torque calculation model is the first output shaft load torque; The torque reduction and recovery rate during the gear shifting process is derived, and the output of the vehicle dynamics model is used as feedback to build a torque reduction and recovery rate limiting model, wherein the output of the torque reduction and recovery rate limiting model is the torque of the first input shaft.

6. The electric vehicle AMT shifting process control simulation method based on Matlab and Adams as claimed in claim 1, characterized in that: The shift actuator control model is used to control the shift motor. The target torque of the shift motor, the target speed of the shift motor, and the gear stage information are input into the shift motor control model to obtain the actual power of the shift motor and the horizontal moving speed of the shift actuator coupling sleeve. The horizontal moving speed of the coupling sleeve is the horizontal moving speed of the shift actuator motor transmitted to the fork head through the mechanical part.

7. The electric vehicle AMT shifting process control simulation method based on Matlab and Adams as claimed in claim 6, characterized in that: The shift actuator control model includes a target speed and torque calculation model, a PID control model, a power supply model, an inverter model, and a brushless DC motor model; the input of the PID control model is the difference between the target speed and the actual speed of the shift motor, the target speed of the shift motor is determined by the speed and torque calculation model, the output of the shift motor is the actual speed and torque of the shift motor, and the actual speed of the shift motor is output through the mechanical part of the shift actuator as the input of the model control module combined with the horizontal movement of the sleeve.

8. The electric vehicle AMT shifting process control simulation method based on Matlab and Adams as claimed in claim 1, characterized in that: The vehicle dynamics equation is specifically: During driving, the vehicle will be subject to the rolling resistance f of the ground and the component force F of the vehicle mass in the direction of gravity. s , air resistance F w , and the acceleration resistance F generated by the acceleration process Δ composition; f = μmgcos(θ); F s =mgsin(θ); F w =δma; Where μ is the rolling resistance coefficient of the vehicle, m is the mass of the vehicle, g is the acceleration of gravity, θ is the ground inclination angle, C D is the air resistance coefficient, A is the windward area, and ρ is the air density, which is about 1.209 kg / m 3 , V is the vehicle's speed, δ is the rotational mass conversion factor, and a is the vehicle's acceleration; Among them J cl is the moment of inertia of a single wheel, J f is the moment of inertia of the engine flywheel, η t For the transmission efficiency of the transmission system, the rotation mass conversion coefficients δ1 and δ2 of the first and second gears are calculated: Among them, J jht is the moment of inertia of the coupling sleeve, η is the transmission efficiency of mechanical transmission, J 1d is the moment of inertia of the gear ring to be engaged in the first gear, J 2d is the moment of inertia of the gear ring to be engaged in the second gear, i1 is the speed ratio of the first gear, and i2 is the speed ratio of the second gear; The total external load force of the vehicle in the first and second gear states is F s1 and F s2 The relationship is: According to the operating characteristics of the drive motor, combined with the relationship between the output torque and the load, the actual dynamic equation of the vehicle is derived as follows: The dynamic equations of a vehicle in one gear are: The dynamic equations of a vehicle in second gear, Where α is the output ratio of the rated torque, T is the rated torque of the motor, n is the actual speed of the motor, n0 is the rated speed of the motor, and P is the rated power of the motor.

9. The electric vehicle AMT shifting process control simulation method based on Matlab and Adams as claimed in claim 8, characterized in that: The current speed of the vehicle, gear information, and output torque of the driving motor are input into the actual load torque calculation model of the first output shaft for calculation, so as to obtain the resistance torque of the first output shaft and the equivalent starting torque to be overcome on the first output shaft; When the input torque of the drive motor is less than the starting torque, the first output shaft load torque is the torque output by the drive motor to the first input shaft; when the input torque of the drive motor is greater than the starting torque, the first output shaft load torque is the first output shaft resistance torque.

10. The electric vehicle AMT shifting process control simulation method based on Matlab and Adams as claimed in claim 1, characterized in that: The derivation of the torque reduction and recovery rate during the gear shifting process is specifically: When the vehicle acceleration is greater than 0, the actual output torque T can be obtained from the vehicle dynamics equation of the whole vehicle. r Relationship with road load: The entire shifting process takes a very short time. The speed change and the road inclination angle can be ignored and regarded as constants. Only the torque change rate T needs to be considered. r changes; According to the impact requirement j≤10m / s 3 ; The ranges of the torque reduction and torque recovery rates for the first and second gears are as follows: When the vehicle acceleration is less than 0, the torque change rate range is:

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