阅读说明：本技术 2amt变速器动力总成换挡协同控制的测试方法及系统 (Testing method and system for 2AMT transmission power assembly gear shifting cooperative control ) 是由 徐海港 张建武 潘胜祥 柴本本 金爱华 肖峰 赵木 于 2021-08-18 设计创作，主要内容包括：本发明涉及一种2AMT变速器动力总成换挡协同控制的测试方法,包括：驱动电机模式切换试验、换挡执行机构和TCU调试试验以及MCU和TCU协同控制负载试验,最后进行试验数据处理,通过对台架试验结果的分析,发现TCU与整车控制存在的问题,从机械结构设计和控制算法优化两个方面分析影响换挡性能的原因,并提出解决方案；负载电机用于模拟整车负载。本发明还涉及一种2AMT变速器动力总成换挡协同控制的测试系统,包括：待测试的2AMT自动变速器、驱动电机、负载电机和上位机。本发明的测试方法,可以实现对电驱动2AMT变速器动力总成换挡协同控制性能的全方位检测,检测结果准确可靠。本发明的测试系统,结构简单合理,测试操作方便快捷。(The invention relates to a testing method for gear shifting cooperative control of a power assembly of a 2AMT (automated mechanical transmission), which comprises the following steps of: the method comprises the following steps of carrying out a mode switching test, a gear shifting execution mechanism and TCU debugging test and an MCU and TCU cooperative control load test on a driving motor, finally carrying out test data processing, finding out the problems existing in the control of the TCU and the whole vehicle through the analysis of a bench test result, analyzing the reasons influencing the gear shifting performance from two aspects of mechanical structure design and control algorithm optimization, and providing a solution; the load motor is used for simulating the load of the whole vehicle. The invention also relates to a test system for the gear-shifting cooperative control of the power assembly of the 2AMT transmission, which comprises the following components: the device comprises a 2AMT automatic transmission to be tested, a driving motor, a load motor and an upper computer. The testing method can realize the omnibearing detection of the gear-shifting cooperative control performance of the power assembly of the electrically-driven 2AMT transmission, and the detection result is accurate and reliable. The test system has simple and reasonable structure and convenient and quick test operation.)

1.2AMT derailleur drive assembly shifts gear cooperative control's test method, its characterized in that includes: the method comprises the following steps of performing a driving motor mode switching test, a gear shifting execution mechanism and TCU debugging test and an MCU and TCU cooperative control load test, wherein the driving motor mode switching test is used for verifying the torque control performance of a driving motor, verifying the rotating speed control performance of the driving motor and analyzing the torque/rotating speed mode switching performance of the driving motor; the gear shifting executing mechanism and the TCU debugging test are used for testing the gear shifting performance and the gear shifting strategy of the gear shifting executing mechanism and debugging the TCU; the MCU and TCU cooperative control load test is used for testing the cooperative control performance of the MCU and the TCU under the simulated load state; and finally, test data processing is carried out, the problems of TCU and finished automobile control are found through analysis of bench test results, and the reasons influencing the gear shifting performance are analyzed from two aspects of mechanical structure design and control algorithm optimization.

2. The testing method for shift coordinated control of the powertrain of the 2AMT transmission as recited in claim 1, wherein in the driving motor mode switching test, the driving motor works in three modes during the shifting process: the system comprises a torque mode, a free mode and a rotating speed mode, wherein the MCU receives an opening value of an accelerator pedal to determine the output torque of a driving motor in the torque mode, and the driving motor does not perform speed closed-loop control; the MCU controls the stator current of the driving motor in a free mode, and the driving motor freely rotates by means of the inertia of the driving motor and does not output torque to the outside; and under the rotating speed mode, the MCU performs rotating speed closed-loop control on the driving motor.

3. The testing method for shift coordinated control of a powertrain of a 2AMT transmission according to claim 2, characterized in that the driving motor mode switching test process is as follows:

1.1, work before test: checking whether the mechanical connection of each component of the rack is complete; checking whether electric leakage exists in the electrical equipment or not, and whether short circuit exists in line connection or not; checking whether each sensor can work normally;

1.2, awakening the power battery: the relay is closed at first when the test is started, and the voltage of the power battery direct-current power supply is regulated to be increased to 330-350V;

1.3, MCU awakening and starting: respectively fixing the gears of the AMT 2 automatic transmission at a first gear and a second gear, adjusting the opening degree of an accelerator pedal, and operating a driving motor;

1.4, applying a rotating speed load by a load motor, adjusting the rotating speed and the torque of the load motor, and controlling an accelerator pedal to adjust the rotating speed of a driving motor to maintain a specific working condition;

1.5, acquiring pedal opening rotating speed and torque signals of a driving motor through a CAN bus, and acquiring rotating speed and torque signals of a load motor through a rack torque meter and an encoder;

1.6, orderly power-off unloading after the test is finished: firstly, unloading the driving motor, turning off the direct-current power supply after the transmission system stops rotating, and stopping the machine when the voltage of the bus is reduced to be within 12V;

1.7, 30 replicates per experiment.

4. The testing method for shift coordinated control of the powertrain of the 2AMT transmission according to claim 1, wherein in the shift actuator test and the TCU debugging test, the control parameters for shift execution are calibrated and optimized; verifying the control performance of the TCU, namely verifying the control performance of the TCU on the gear shifting motor when no load exists, and then performing gear shifting tests at different rotating speeds to prove the reliability of the gear shifting process; finally, simulating the actual road condition of the whole vehicle to test the automatic upshift and downshift process under the actual working condition; when the actual road condition of the whole vehicle is simulated, the driving motor on the test bed drags the running circulation working condition, and the actual road condition of the whole vehicle is simulated to test the automatic gear-up and gear-down process under the actual working condition; the gear shifting control strategy is realized by a TCU, the TCU has the control function of carrying out comprehensive analysis and calculation according to the collected rotating speed signal, position signal and switching signal, judging the vehicle condition, the road surface condition, the intention of a driver and the gear shifting time, and then sending a control instruction to a driving module, and the driving module drives an AMT gear shifting motor after receiving the control instruction; the gear shifting rules are divided into three types, namely dynamic, economical and comprehensive gear shifting rules, and when the vehicle starts by using a first gear, the gear is not shifted up until the speed reaches 50km/h, and meanwhile, in order to avoid the situation that the working rotating speed of a power motor is high for a long time under the condition that the vehicle runs at a low speed, the gear shifting speed is not too low; in the bench test, a static state shift test and a load shift test are respectively performed.

5. The method for testing the shift coordination control of the powertrain of the 2AMT transmission according to claim 4, characterized in that the specific steps of performing the shift actuator test and the TCU debugging test are as follows:

2.1, enabling the driving motor and the load motor to be in a free state, manually rotating an output half shaft, and determining that the whole transmission system works normally;

2.2, starting a test, firstly checking whether the installation of a gear sensor is correct, then supplying a 12V direct-current power supply to the TCU, and manually calibrating the positions of a neutral gear, a first gear and a second gear by combining sensor signals;

2.3, after calibration is finished, starting to execute 50-100 cycles of the first gear I and second gear II and first gear I tests;

2.4, if the gear shifting motor is locked, disconnecting the 12V power supply, and calibrating the number of turns of each gear position again until the gear shifting motor is not locked;

2.5, after the experiment, the number of turns accurate data that neutral position kept off to I and II keeps off is recorded for further perfect adding, the speed reduction and the ride comfort of shifting of process of shifting the gear motor.

6. The testing method for shift coordinated control of the powertrain of the 2AMT transmission according to claim 1, wherein in a coordinated control load test of the MCU and the TCU, the TCU firstly determines the shift timing according to the information of the vehicle speed sensor and the pedal opening degree, and then performs information interaction with the MCU to coordinate to complete the shift process; when the vehicle is shifted, data interaction is carried out between the MCU and the TCU in real time; in the gear shifting process, the driving motor is switched from a torque mode to a free mode, then switched from the free mode to a rotating speed mode, then switched from the rotating speed mode to the free mode, and finally recovered from the free mode to the torque mode; the method is characterized in that the gear shifting process is rapid and reliable, firstly, the mode switching process of the driving motor is debugged and calibrated systematically, the control logic in the MCU is modified to meet the instruction requirement required by gear shifting, and meanwhile, the mode switching process of the driving motor is debugged and calibrated.

7. The method for testing the shift cooperative control of the powertrain of the 2AMT transmission as recited in claim 6, wherein the step of testing the cooperative control load of the MCU and the TCU is as follows:

3.1, preparation before test: checking whether the gear of the AMT automatic transmission is in a neutral gear or not and whether the power supply of a TCU is normal or not;

3.2, electrifying the power battery: providing 350V high-voltage direct current for a driving motor, setting a gear shift lever to be a forward gear, driving a motor torque mode and a load motor rotating speed mode;

3.3, controlling an accelerator pedal opening signal: increasing the opening degree signal, and driving the motor to increase the speed until the rotating speed exceeds a gear-up line to finish gear-up; then controlling the opening degree signal of the pedal to reduce, so that the driving motor decelerates, passes through a gear descending line, further realizing gear descending operation, and thus carrying out cyclic gear ascending and descending operation;

3.4, finishing the test: firstly, the load motor is unloaded, then the drive motor is unloaded, the high-voltage power supply is closed, and the machine is stopped.

8. The testing method for shift coordinated control of the powertrain of the 2AMT transmission according to claim 1, characterized in that the data in the test is processed by imaging; adopt the CAN network to realize TCU and MCU's cooperative communication, the data interaction communication content between TCU and the MCU includes: the TCU sends a gear shifting starting instruction, the TCU sends a gear shifting completion instruction, the TCU sends a gear shifting request, the TCU sends transmission gear information, the MCU sends torque information of 0, the MCU sends a speed regulating completion instruction, the MCU replies the gear shifting request, and the MCU sends the rotating speed of the driving motor and the opening data of the electric door of the pedal plate.

A9.2 AMT transmission powertrain shift coordinated control test system, characterized in that, applying the test method of claim 1, comprises: the system comprises a 2AMT automatic transmission to be tested, a 2AMT automatic transmission, an upper computer, a load motor, a monitoring instrument, a load system and a control system, wherein the 2AMT automatic transmission to be tested is respectively connected with a driving motor and the load motor; the load motor is used for simulating the load of the whole vehicle, and torque and rotating speed information are collected through a torque sensor and a rotating speed sensor which are arranged on the load motor and are transmitted to the upper computer through an Ethercat network.

10. The system of claim 12, wherein the driving motor is connected to the input shaft of the 2AMT automatic transmission through an oldham coupling, one side of the output shaft of the 2AMT automatic transmission is connected to the load motor through a half shaft and a transition flange, the other side of the output shaft of the 2AMT automatic transmission is connected to the fixing bracket through a half shaft and is fixed to the test bed through the fixing bracket, the driving motor is a three-phase asynchronous driving motor, the driving motor is connected to the MCU through a high voltage copper wire, the power battery provides a 330V high voltage dc power supply for the MCU, the MCU terminal is connected to the power analyzer, and the MCU is connected to the TCU through a CAN.

Technical Field

The invention belongs to the technical field of automobile production and manufacturing, and particularly relates to a testing method and system for gear shifting cooperative control of a power assembly of a 2AMT (automated mechanical transmission) of an electric automobile.

Background

Electric vehicles have been rapidly developed in recent years as the most important member of a new energy vehicle family. In the technical development process of the electric automobile, the 2AMT (electrically driven two-gear electrically controlled mechanical) automatic transmission matched with the electric automobile can improve the transmission performance of the electric automobile, so that the automobile can meet the requirements of the highest speed, starting acceleration and climbing at the same time, the good dynamic property of the automobile at low speed can be realized, the requirement of the highest speed of the automobile can be met, and the electric automobile has good economical efficiency at high speed. After the 2AMT transmission body is machined and assembled, calibration and performance tests must be performed on the cooperative control and gear shifting strategies of the 2AMT automatic transmission, the Transmission Controller (TCU), the driving motor and the driving motor controller (inverter, MCU) in a laboratory.

In the development process of the pure electric vehicle power system, a bench test of the power system is a very necessary link. The bench test bed can simulate the actual road running condition of the automobile approximately, and further can effectively reduce the time of the whole automobile test. The bench test can verify the coordination control logic between the electric drive systems, reduce the calibration time and the research cost, and reduce the danger of the sample vehicle road test. However, no complete testing method and system for testing the gear shifting cooperative control of the powertrain of the 2AMT transmission exists at present.

Disclosure of Invention

In order to solve the technical problem, the invention provides a testing method and a testing system for gear shifting cooperative control of a power assembly of a 2AMT (automated mechanical transmission) of an electric automobile. The technical scheme adopted by the invention is as follows:

a testing method for 2AMT transmission power assembly gear shifting cooperative control comprises the following steps: the method comprises the following steps of a driving motor mode switching test, a gear shifting execution mechanism and TCU debugging test and an MCU and TCU cooperative control load test, wherein the driving motor mode switching test is used for verifying the torque control performance of a driving motor, verifying the rotating speed control performance of the driving motor and analyzing the torque/rotating speed mode switching performance of the driving motor, the gear shifting execution mechanism and the TCU debugging test are used for testing the gear shifting performance and the gear shifting strategy of the gear shifting execution mechanism and debugging the TCU, the MCU and TCU cooperative control load test is used for testing the cooperative control performance of the MCU and the TCU in a simulated load state, finally, test data processing is carried out, the problems existing in the TCU and finished automobile control are found through analyzing a bench test result, the reasons influencing the gear shifting performance are analyzed from two aspects of mechanical structure design and control algorithm optimization, and a solution is provided; the load motor is used for simulating the loading of the vehicle, on one hand, the load of the vehicle is different, and on the other hand, the road conditions and the friction coefficients of the vehicle are different, so the loading is different. The bench test method is mainly used for evaluating the gear shifting smoothness of the 2AMT transmission, the power performance of the whole vehicle and the like, and verifying the gear shifting strategy, the MCU and TCU programs and the cooperative rationality thereof, the matching characteristic of the whole vehicle and the rationality of the structural design.

A2 AMT transmission power assembly gear-shifting cooperative control test system applies the test method and comprises the following steps: the test system comprises a 2AMT automatic transmission to be tested, a 2AMT automatic transmission, a driving motor, a load motor, a cross coupling, a fixing support, an upper computer, a cross coupling, a half shaft, a transition flange, a half shaft, a fixing support, a cross coupling, a transition flange, a fixing support, a test bench, a test machine and a monitoring instrument, wherein the upper computer is respectively connected with the driving motor, the load motor and the drive motor, the drive motor and the upper computer sends control signals to the load motor and the driving motor in real time and the drive system and is responsible for the control of the whole load system and the collection of the data; the load motor is used for simulating the load of the whole vehicle, and torque and rotating speed information are collected through a torque sensor and a rotating speed sensor which are arranged on the load motor and are transmitted to the upper computer through an Ethercat network.

The invention has the beneficial effects that:

according to the testing method, the testing of the 2AMT transmission power assembly gear-shifting cooperative control is decomposed into a driving motor mode switching test, a gear-shifting executing mechanism and TCU debugging test and a MCU and TCU cooperative control load test, so that the comprehensive detection of the gear-shifting cooperative control performance of the electrically-driven 2AMT transmission power assembly can be realized, and the detection result is accurate and reliable.

The test system has simple and reasonable structure and convenient and quick test operation.

Drawings

FIG. 1 is a flow chart of a TCU controlling a shift operation according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the logic of data interaction communication between a TCU and an MCU according to an embodiment of the present invention;

FIG. 3 is a control flow diagram illustrating an embodiment of the present invention;

FIG. 4 is a schematic illustration of the imaging process of test data according to an embodiment of the invention;

FIG. 5 is a schematic structural diagram of a test system according to an embodiment of the present invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention.

An electric drive system for an electric vehicle, comprising: the driving motor, the driving Motor Controller (MCU), the 2AMT automatic transmission body and the Transmission Controller (TCU) need to debug and calibrate each component module before carrying out the real vehicle test so as to better match the vehicle. The connecting part required by the test needs to be prepared in the early stage of the bench test, the terminal connected with the electric appliance is matched, the sensor required by the test is arranged, and the measurement and control system is debugged. The clutch-free gear shifting test realizes the cooperative control of the driving motor and the transmission, and the process needs the quick switching of the driving motor between a rotating speed mode and a torque mode, the accurate position control of the gear shifting execution motor and the like. In order to verify the smoothness of the gear shifting test, the whole process needs to be disassembled into a driving motor mode switching test, a gear shifting actuating mechanism test, a TCU debugging test and a final cooperative control load test.

The test principle is as follows: when the electric vehicle normally runs, the driving motor is in a torque mode. In the gear shifting process, the driving motor needs to be regulated, so that the MCU needs to switch the working state of the driving motor to a rotating speed mode. Before the current gear is removed, the working mode of the driving motor is switched to a free running mode from a torque driving mode, the torque at the input end of the transmission is zero, which is equivalent to the clutch separation process of a manual transmission, and therefore the gear shifting motor can smoothly drive the synchronizer to complete neutral gear removal operation. When the synchronizer is in a neutral position, an input shaft and an output shaft of the transmission are in a separated state, an input end of the transmission is connected with the driving motor, and an output end of the transmission is connected with wheels through the transmission shaft, the main speed reducer and the half shaft. Because the inertia of the whole vehicle is large, the rotating speed of the output shaft of the transmission is basically kept unchanged in the gear shifting process, and because the transmission ratio between the input shaft and the output shaft is changed when the transmission is switched from one gear to another gear, in order to reduce the impact in the gear shifting process, the rotating speed of the input shaft of the transmission needs to be actively controlled, so that the input shaft of the transmission can be matched with a new gear. Thus, the operating mode of the drive motor will be switched from the free running mode to the rotational speed mode. The rotation speed is automatically adjusted through the driving motor, and the rotation speed difference between the driving part and the driven part of the synchronizer is reduced; after the motor speed regulation is finished, in order to smoothly engage a gear, the working mode of the driving motor needs to be changed from a rotating speed mode to a free running mode so that the automatic transmission can smoothly enter a target gear; after the gear is engaged, the working mode of the driving motor is switched back to the torque driving mode from the free running mode, the MCU restores the driving motor to the torque mode again, the driving torque is output according to the driving intention, and the gear shifting process is completed.

The invention carries out test on the gear-shifting cooperative control of the power assembly of the electrically-driven 2AMT transmission of the electric vehicle, and can be disassembled into the following steps: and finally, carrying out test data processing, and constructing a comprehensive test system for the gear shifting cooperative control of the power assembly of the electrically-driven 2AMT transmission.

1. And (5) performing a driving motor mode switching test.

In the novel power system of the driving motor +2AMT, due to the fact that a gear shifting process exists, the driving motor needs to adopt different mode control according to gear shifting requirements. During the whole gear shifting process, the driving motor mainly works in three modes: torque mode, free mode, and speed mode.

(a) Torque mode. At this time, the MCU receives the opening value of the accelerator pedal to determine the output torque of the driving motor. At this time, the accelerator pedal opening reflects the torque demand of the driver on the drive motor, and the drive motor does not perform speed closed-loop control.

(b) Free mode. At this time, the MCU controls the stator current of the driving motor to gradually decrease the original current until it becomes 0. At the moment, the driving motor is in a free mode, and in the free mode, the driving motor freely rotates by means of inertia of the driving motor, and does not output torque outwards.

(c) Speed mode. At the moment, the MCU performs rotating speed closed-loop control on the driving motor, namely, the driving motor is adjusted to rotate within a certain error range according to an expected rotating speed instruction.

In the invention, the selected driving motor is an alternating current asynchronous motor (IM), and is controlled by adopting a vector control method, and the method is realized by adopting a rotor magnetic field orientation mode. The basic idea is as follows: under the principle that magnetic potential and power are not changed, a mathematical model of a driving motor under a static ABC coordinate system is converted into a mathematical model under a two-phase rotating coordinate system through Clarke conversion and Park conversion by adopting orthogonal conversion.

Under a two-phase rotating coordinate system d-q, the stator current vector of the asynchronous machine is decomposed into two direct current components i oriented according to the rotor magnetic field_dAnd i_qWherein control i_dEquivalent to controlling the magnetic flux, control i_qCorresponding to controlling torque. Under a rotating coordinate system d-q, an asynchronous motor rotor flux linkage equation based on rotor magnetic field directional control is as follows:

in the formula T_rIs the rotor time constant, T_r＝L_r/R_r，i_sdIs the component of the stator current on the d-axis. It can be seen that the rotor flux linkage psi_rWith stator current component i_sdThe first-order inertia link is formed between the two. Therefore, the excitation current i is well controlled_sdThe rotor flux linkage psi can be controlled_r. At this time, the torque equation of the driving motor is:

it can be seen that the torque of the drive motor is related to the stator current q-axis component i_sqAnd rotor flux linkage psi_rIs proportional. Thus, by controlling i_sdAnd i_sqTo control the electromagnetic torque of the drive motor. In the control of the conventional ac motor, the control is generally performed according to the output characteristics of the motor at different stages of torque and rotation speed. When the rotation speed of the driving motor is below the basic speed, maintaining the exciting current i_sdFor nominal values by regulating i_sqThe torque output is changed, and the constant torque control is realized; when the rotating speed of the driving motor is above the basic speed, the exciting current i is adjusted_sdHold i_sd·ω_rConstant while adjusting the torque current i_sqAnd ensure T_e·ω_rAnd the magnetic flux is approximately equal to a constant, and the flux weakening control is realized.

In the torque control mode, the MCU sets a torque target value of the driving motor through the opening degree of an accelerator pedal according to a driver instruction and a preset control strategy, and directly adjusts current components of a d axis and a q axis of the driving motor to realize control of the output torque of the driving motor. At this time, the torque is directly used for driving the traction vehicle by adopting open-loop control.

Under the rotating speed control mode, the MCU adjusts the target rotating speed of the rotating speed controller according to a speed regulating instruction given by the TCU, so that the output rotating speed of the driving motor quickly reaches the specified rotating speed. In order to shorten the gear shifting time as much as possible, the faster the speed regulation response of the driving motor is, the better the speed regulation response is. In the rotating speed control, the MCU adopts rotating speed closed-loop control to quickly finish the speed regulation process.

The bench test for switching the modes of the driving motor mainly comprises three parts: verifying the torque control performance of the driving motor, verifying the rotating speed control performance of the driving motor and analyzing the torque/rotating speed mode switching performance of the driving motor.

The driving motor mode switching test process is as follows:

1.1, work before test: checking whether the mechanical connection of each component of the rack is complete; checking whether electric leakage exists in the electrical equipment or not, and whether short circuit exists in line connection or not; checking whether each sensor can work normally, and the like;

1.2, awakening the power battery: the relay is closed at first when the test is started, and the voltage of the power battery direct-current power supply is regulated to be increased to 330-350V;

1.3, MCU awakening and starting: respectively fixing the gears of the AMT 2 automatic transmission at a first gear and a second gear, adjusting the opening degree of an accelerator pedal, and operating a driving motor;

1.4, applying a rotating speed load by a load motor, adjusting the rotating speed and the torque of the load motor, and controlling an accelerator pedal to adjust the rotating speed of a driving motor to maintain a specific working condition;

1.5, controlling a platform monitoring system: the method comprises the following steps that data acquisition acquires pedal opening rotating speed and torque signals of a driving motor through a CAN bus, and acquires rotating speed and torque signals of a load motor through a rack torque meter and an encoder;

1.6, orderly power-off unloading after the test is finished: firstly, unloading the driving motor, turning off the direct-current power supply after the transmission system stops rotating, and stopping the machine when the voltage of the bus is reduced to be within 12V;

and 1.7, analyzing test data, and repeating the test 30 times in order to ensure the reliability of the test.

2. A gear shifting actuating mechanism test and a TCU debugging test.

The electric gear shifting execution system is composed of a gear shifting execution mechanism and an execution motor, wherein the gear shifting execution mechanism comprises a brushless direct current gear shifting motor, a worm and gear speed reducing mechanism, a cam drum, a gear shifting fork, a synchronizer, a neutral position sensor and the like, and the gear shifting execution motor adopts a high-performance rare earth permanent magnet brushless direct current motor. The design goal of the electric gear shifting actuating mechanism is to realize accurate, reliable and quick gear shifting. The shift technical performance indexes are as follows: shift path s is 21mm, shift force F >300N, and shift time t <1s or t is minimal. The electrically driven 2AMT Transmission Control Unit (TCU) comprises a housing, a card, a Printed Circuit Board (PCB) and connectors, the most essential of which is the PCB, which mainly comprises: the device comprises a power module, a rotating speed signal acquisition module, a position signal acquisition module, a switch signal acquisition module, a control module, a serial port communication module, a CAN communication module, a driving module and the like. The software part of the TCU mainly comprises functions of I/O, TIM counting, A/D sampling module, CAN communication, PWM driving and the like. Referring now to FIG. 1, a flowchart illustrating a TCU controlling a shift operation is shown in accordance with an embodiment of the present invention. The gear shifting executing mechanism firstly receives a gear shifting instruction of the TCU to carry out neutral gear shifting operation, and carries out synchronizer position feedback through a Hall signal of a gear shifting motor and a neutral gear position sensor to determine when the gear shifting motor reaches a neutral gear position, so that the TCU sends a speed regulating instruction to the MCU. After the speed regulation is finished, the TCU controls the gear shifting motor to carry out gear engaging operation, at the moment, whether the target gear is reached is determined through a Hall signal of the gear shifting motor, meanwhile, the position information of the synchronizer is fed back to the TCU, and then the driving motor is controlled to recover the torque mode. The control of the gear shift actuating mechanism determines the gear shift time and the reliability of gear shift, and some control parameters of gear shift execution need to be calibrated and optimized, so that a bench test related to gear shift execution needs to be designed.

The TCU is an electronic control unit of the 2AMT, and when receiving an output shaft rotating speed signal and an instruction sent by the MCU, the TCU controls the forward and reverse rotation of the gear shifting motor through the gear shifting logic to complete the gear shifting or gear shifting operation. To verify the control performance of the TCU, the control performance of the TCU on the shift motor needs to be verified first when no load exists, and then shift tests at different rotation speeds are performed to prove the reliability of the shift process. And finally, on a test bed, a driving motor drags a running circulation working condition, and the actual road condition of the whole vehicle is simulated to test the automatic gear-up and gear-down process under the actual working condition.

In the design process of the transmission of the electrically-driven 2AMT system, all key parameters of a gear shaft system need to be considered, such as the tooth number and the reduction ratio of a main speed reducer, the tooth number and the reduction ratio of gears of 1 gear and 2 gear determined by the reduction ratio of two gears, and the like. The design and optimization of the obtained key parameters of the transmission of the electrically driven 2AMT system. When each component of the transmission gear train, the bearing, the shell and the like is designed, the sub-components need to be considered to be integrally assembled. The electrically-driven 2AMT system needs to realize functions of vehicle driving, gear shifting control and the like, and therefore reasonable sensor configuration needs to be adopted to collect required state information, so that the designed function is stably realized.

The gear shifting strategy and the gear shifting rule are key contents of the control of the electrically-driven 2AMT system, and the whole electric passenger vehicle can be ensured to have both dynamic property and economical efficiency through the design of the gear shifting rule. The shift control strategy is implemented primarily by the TCU. For state information required by TCU control, the TCU acquires the rotation speed of an output shaft of the gearbox through a rotation speed signal module; the position signal module is used for acquiring the position of an accelerator pedal, the gear position of a gearbox and the like of the whole vehicle; and key switch, brake signal and the like of the whole vehicle are collected through the switch signal module. The TCU control function is to carry out comprehensive analysis and calculation according to the collected rotating speed signal, position signal, switch signal and the like, judge the vehicle condition, the road surface condition, the driver intention and the gear shifting time, send a control instruction to the driving module, simultaneously carry out data transmission with the serial port communication module and the CAN communication module, receive useful information of other controllers of the whole vehicle and send a command to the other controllers to assist the AMT to control; the serial port communication module and the CAN communication module are used for keeping the AMT and other controllers of the whole vehicle to perform data transmission; the driving module drives the AMT gear shifting motor after receiving the control instruction of the control module.

The shift schedule is divided into three categories, namely, dynamic, economic and comprehensive shift schedules. When the vehicle starts by using the first gear, the vehicle does not perform the upshifting before the speed reaches 50 km/h. Meanwhile, in order to avoid the situation that the working rotating speed of the power motor is high for a long time under the condition of low-speed running of the vehicle, the gear-down speed is not low. In the bench test, a static state shift test and a load shift test are respectively performed.

Static shift test. When the driving motor and the load motor are both in a static state, the TCU controls the gear shifting execution motor to perform circulating gear lifting operation. And controlling whether the synchronizer is in place or not according to the Hall position signal, correcting the accumulated error caused by the Hall in the circulation process through a neutral position sensor, and controlling the forward and reverse rotation of the gear shifting motor to control the up-down gear operation. The electrically driven 2AMT system can smoothly realize a shift function under a stationary condition. The gear shifting process takes about 1s, and gear shifting can be realized quickly, so that smooth running of the whole vehicle in the electrically-driven 2AMT driving process is ensured.

And (4) carrying out a load shift test. When driving motor operates in the moment of torsion mode, load motor operates in the rotational speed mode, and electric drive 2AMT test bench has simulated the whole car operating mode of electric motor car this moment. The control of the pedal opening is equivalent to the control of the speed of the whole vehicle, so that the rotating speed of the driving motor passes through a gear shifting line to perform gear shifting operation, including dynamic gear shifting and economical gear shifting.

When the driving motor and the load motor are both in a static state, the TCU controls the gear shifting execution motor to perform circulating gear lifting operation. Whether the synchronizer is in place or not is controlled according to the Hall signal of the gear shifting motor, the accumulated error caused by the Hall signal in the circulation process is corrected through the neutral position sensor, and the up-down gear operation is controlled by controlling the forward and reverse rotation of the gear shifting motor.

The specific steps for carrying out the gear shifting actuating mechanism test and the TCU debugging test are as follows:

2.1, firstly, enabling a driving motor and a load motor to be in a free state, manually rotating an output half shaft, and enabling the half shaft to easily rotate to determine that the whole transmission system works normally;

2.2, starting a test, firstly checking whether the installation of a gear sensor is correct, then supplying a 12V direct-current power supply to the TCU, and manually calibrating the positions of a neutral gear, a first gear and a second gear by combining sensor signals;

2.3, after calibration is finished, starting to execute 50-100 cycles of the first gear I and second gear II and first gear I tests;

2.4, if the gear shifting motor is locked, immediately disconnecting the 12V power supply, and re-calibrating the number of turns of each gear position until the gear shifting motor is not locked;

2.5, after the experiment, the number of turns accurate data that neutral position kept off to I and II keeps off is recorded for further perfect adding, the speed reduction and the ride comfort of shifting of process of shifting the gear motor.

MCU and TCU cooperative control load test, namely: and the MCU + TCU cooperatively controls gear shifting.

The TCU is the brain of the automatic transmission and the control shift strategy determines the shift quality of the automatic transmission. The TCU firstly determines the gear shifting time according to the vehicle speed sensor and the pedal opening information, and then carries out information interaction with the MCU to cooperatively complete the gear shifting process. In order to verify the shift performance of the automatic transmission, a TCU test was finally performed. In order to smoothly complete gear shifting, the TCU and the MCU are matched to work cooperatively. Therefore, information exchange between the TCU and the MCU is very important. The Controller Area Network (CAN) is the most extensive communication network currently applied to automobiles, so the invention adopts the CAN network to realize the cooperative communication between the TCU and the MCU. Under the general running state of the vehicle, the MCU sends parameters such as the rotating speed, the torque and the like of the power motor to the TCU on time through the CAN network, so that the TCU CAN judge the running state of the system; when the vehicle is shifted, real-time data interaction between the MCU and the TCU is needed so as to complete corresponding work of each stage in the shifting process and ensure that the system can smoothly and reliably complete shifting.

The data interaction between the TCU and the MCU of the 2AMT system of the present application is completed by means of the CAN message, as shown in fig. 2, which is a schematic diagram of the data interaction communication logic between the TCU and the MCU according to the embodiment of the present invention. The data interactive communication content between the TCU and the MCU comprises the following steps: message 0x1000A1B1, representing that the TCU issues a "shift start" instruction; message 0x1001A1B1, representing that the TCU sends a "gear completion" instruction; message 0x1002A1B1, representing the TCU issuing a "shift request"; message 0x1003A1B1, representing the TCU issuing a "shift request"; message 0x1004A1B1, representing the TCU sending "transmission gear information" (once every 20 ms); a message 0x1000B1A1, representing that the MCU sends out the information that the torque is 0; a message 0x10001B1A1 represents that the MCU sends out a speed regulation completion instruction; message 0x1002B1a1, representing the MCU replying to a "shift request"; and a message 0x1003B1A1 represents that the MCU sends data such as the rotating speed of the driving motor, the opening degree of a foot pedal switch and the like.

In the test process, the gear shifting condition can be accurately judged by trial calculation of the number of turns of the gear shifting motor. For example, the message 1005A1B1 receives the message 0101799a, the high byte 0x01 (hexadecimal), the low byte 0x79 (hexadecimal), the calculation formula: the number of rotations of the shift motor is (256 × HEX2DEC (high byte) + HEX2DEC (low byte))/24 is (256 × 1+121)/24 is 15.7. At the moment, the number of turns of the gear shifting motor is 15.7, and the number of turns of the gear shifting motor is cleared every time the gear picking/gear shifting action is completed.

Fig. 3 is a specific control flow diagram of the gear shifting process according to the embodiment of the present invention. In the whole process, the driving motor is switched from the torque mode to the free mode, then switched from the free mode to the rotating speed mode, then switched from the rotating speed mode to the free mode, and finally recovered from the free mode to the torque mode. In order to realize the rapidness and reliability of the gear shifting process, firstly, the debugging and calibration of a system are carried out on the mode switching process of the driving motor. Aiming at the existing driving motor and MCU, some control logics in the MCU need to be modified to meet the instruction requirements needed by gear shifting, and meanwhile, a bench test is needed to debug and calibrate the mode switching process of the driving motor.

The steps of the cooperative control load test of the MCU and the TCU are as follows:

3.1, preparation before test: checking whether the gear of the AMT automatic transmission is in a neutral gear or not and whether the power supply of a TCU is normal or not;

3.2, electrifying the power battery: the driving motor is provided with 350V high-voltage direct current, the gear shift lever is arranged on a forward gear, and the driving motor is in a torque mode and a load motor is in a rotating speed mode.

3.3, controlling an accelerator pedal opening signal: increasing the opening degree signal, and driving the motor to increase the speed until the rotating speed exceeds a gear-up line to finish gear-up; and then the opening degree signal of the pedal is controlled to be reduced, so that the driving motor is decelerated and passes through a gear-down line, and the gear-down operation is realized. This causes several cycles of the shift operation.

3.4, finishing the test: firstly, the load motor is unloaded, then the drive motor is unloaded, the high-voltage power supply is closed, and the machine is stopped.

4. And (6) processing test data.

4.1, graphical data post-processing and experimental reports.

The data recorded by the test process measurement comprises: the bench torque meter and the rotation speed sensor collect physical quantities such as motor torque and rotation speed and the power meter collects and records data such as current and voltage. In the bench test process, in order to visually see the shift up and down process of the AMT 2, the data in the test is subjected to imaging processing, and a schematic diagram of imaging processing of the test data of the embodiment of the invention shown in fig. 4 is obtained. As can be seen from fig. 4, the shift-up 1 time is 187.4 seconds to 188 seconds for 0.6 seconds, the shift motor rotates 20 turns, and the shift-up 2 time is 188.5 to 190.6 seconds for 1.1 seconds, which indicates that mechanical failure, such as unsmooth operation, locked rotation, mechanical jamming and the like, occurs in the shift process of the AMT transmission system, and the problem of accumulation of neutral position errors may exist in the shift process; during the first second of 1-2 gear up-shift, the torque of the driving motor fluctuates between 0 and 80NM, the rotating speed is regulated from 2600 to 1400, the speed is reduced and the torque is increased, and the fluctuation in the middle of 188.6 to 189 seconds also shows the mechanical jamming in the initial process of 1-2 gear up-shift. Through the analysis and diagnosis of the bench test process, the problems of the 2AMT transmission, the TCU, the whole vehicle control and the like can be found, so that the problems can be solved and the test can be completed smoothly.

4.2 the shift process is optimized.

Through the analysis of the bench test result, the problems of the TCU and the whole vehicle control can be found, then the reasons influencing the gear shifting performance are analyzed from two aspects of mechanical structure design and control algorithm optimization aiming at the whole gear shifting result, and a targeted solution is provided. Aiming at the problem of accumulation of neutral position errors possibly existing in the gear shifting process, a sensor with higher precision by one level or a method for further improving position calibration can be selected; corresponding preparation work is carried out aiming at the phenomena of mechanical faults such as unsmooth operation, even mechanical blockage and the like which can occur in the operation process of the power system. After the bench test is successfully completed, through analysis of test result data, the reasons influencing the gear shifting performance can be analyzed from several aspects such as mechanical structure design and control algorithm optimization, and a scheme for pertinently optimizing the gear shifting process and improving the gear shifting time is provided, such as further optimization of a gear shifting mechanism and control algorithm optimization of a gear shifting motor.

The following table is an exemplary embodiment of a test method for an electrically-driven two-speed automatic transmission of the present invention:

serial number	Name of component	Make/model/specification
			1	Power battery and BMS thereof	350VDC time wind
2	Power analyzer	Time wind
			3	Driving Motor Controller (MCU)	Shenzhen blue sea Huateng
4	Driving motor	Shandong-De-Puda three-phase asynchronous induction motor
			5	Double-speed transmission assembly	Time wind
6	Gear shifting motor	Changzhou multi-dimensional DC brushless motor 57ZWS601
			7	Transmission Controller (TCU)	Time wind
8	Low-speed load motor	Beijing Shenli test and control
			9	Torque and rotating speed sensor	Beijing Shenli test and control
10	Data acquisition equipment	Beijing Shenli test and control
			11	Upper computer and measurement and control software	Time wind

By utilizing the test equipment in the table, comprehensive test of gear shifting cooperative control of the power assembly of the electrically-driven 2AMT transmission can be realized.

Fig. 5 is a schematic structural diagram of a test system according to an embodiment of the present invention. A2 AMT transmission power assembly gear-shifting cooperative control test system applies the test method and comprises the following steps: 2AMT automatic gearbox that awaits measuring, 2AMT automatic gearbox are connected with driving motor and load motor respectively, are connected through the cross-coupling between driving motor and the 2AMT automatic gearbox input shaft, and 2AMT automatic gearbox output shaft one side is connected with the load motor through semi-axis and transition flange, and the opposite side is connected and then is fixed on the test bench through semi-axis and fixed bolster. The driving motor is a three-phase asynchronous driving motor, the driving motor is connected with a Motor Controller (MCU) through a high-voltage copper wire, the power battery provides a 330V high-voltage direct-current power supply for the MCU, and a connecting terminal of the MCU is connected with a power analyzer which can detect three-phase alternating-current voltage and current signals. The Motor Controller (MCU) is a power module for power conversion, and is responsible for converting 350V high-voltage direct current of the power battery pack into three-phase alternating current and supplying power to the driving motor. Meanwhile, under the control of the MCU, the driving motor can operate in a certain given torque and rotating speed state. The upper computer is respectively connected with the driving motor, the load motor and the monitor, sends control signals to the load motor and the driving motor in real time, and is responsible for controlling the whole load system and the driving system and collecting some main data. The load motor is used for simulating the load of the whole vehicle, and torque and rotating speed information is collected through a torque and rotating speed sensor and is transmitted to the upper computer through an Ethercat network. The MCU is connected with the TCU through the CAN, so that the real-time control of the gear shifting process CAN be realized. The upper computer adopts a computer, the upper computer adopts a LabView measurement and control system to be matched with a NI data board card to control the rack in real time, and a graphical interface is more convenient according to the requirements of a user; the host computer possesses the data analysis function, analyzes the data that each CAN point gathered to obtain different data results, form different graphical curve, the overall performance condition of 2AMT derailleur power assembly coordinated control that shifts is analyzed out.