CN113624490B

CN113624490B - Gear shifting cooperative control testing method and system for power assembly of 2AMT (automated mechanical transmission)

Info

Publication number: CN113624490B
Application number: CN202110951563.9A
Authority: CN
Inventors: 徐海港; 张建武; 潘胜祥; 柴本本; 金爱华; 肖峰; 赵木
Original assignee: Shandong Shifeng Commercial Vehicle Co ltd; Shandong Shifeng Group Co Ltd
Current assignee: Shandong Shifeng Commercial Vehicle Co ltd; Shandong Shifeng Group Co Ltd
Priority date: 2021-08-18
Filing date: 2021-08-18
Publication date: 2023-07-07
Anticipated expiration: 2041-08-18
Also published as: CN113624490A

Abstract

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: the method comprises the steps of a driving motor mode switching test, a gear shifting executing mechanism and TCU debugging test and an MCU and TCU cooperative control load test, finally performing test data processing, finding out problems of the TCU and the whole vehicle control through analysis of bench test results, analyzing reasons affecting 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 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 electric drive 2AMT transmission, and the detection result is accurate and reliable. The test system provided by the invention has a simple and reasonable structure, and is convenient and quick to test and operate.

Description

Gear shifting cooperative control testing method and system for power assembly of 2AMT (automated mechanical transmission)

Technical Field

The invention belongs to the technical field of automobile production and manufacturing, and particularly relates to 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.

Background

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

In the development process of the power system of the pure electric vehicle, a bench test of the power system is an extremely necessary link. The bench test bed can approximate the actual road running condition of an automobile, and further can effectively reduce the time of the whole automobile test. The bench test can also verify the coordination control logic between the electric drive systems, so that the calibration time and the research cost are reduced, and the danger of the road test of the sample car is reduced. However, a complete test method and a complete test system for testing shift cooperative control of a power assembly of a 2AMT transmission are not available at present.

Disclosure of Invention

In order to solve the technical problems, the invention provides a testing method and a 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 test method for gear shifting cooperative control of a 2AMT transmission power assembly comprises the following steps: the method comprises the steps of a driving motor mode switching test, a gear shifting executing 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 torque control performance of a driving motor, verifying rotation speed control performance of the driving motor and analyzing torque/rotation speed mode switching performance of the driving motor, the gear shifting executing mechanism and the TCU debugging test are used for testing gear shifting performance and gear shifting strategy of the gear shifting executing mechanism, the TCU debugging, the MCU and TCU cooperative control load test is used for testing cooperative control performance of the MCU and the TCU in a simulated load state, finally test data processing is carried out, problems of the TCU and whole vehicle control are found through analysis of bench test results, and reasons affecting 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 loading of the vehicle, on one hand, the load of the vehicle is different, on the other hand, the road conditions of the vehicle are different, and the friction coefficients are different, so that the loading is different. The bench test method is mainly used for evaluating gear shifting smoothness of the 2AMT transmission, dynamic performance of the whole vehicle and the like, verifying gear shifting strategies, MCU and TCU programs and coordinated rationality thereof, matching characteristics of the whole vehicle and rationality of structural design.

A test system for gear shifting cooperative control of a 2AMT transmission power assembly comprises the following steps: the automatic transmission to be tested is 2AMT, the automatic transmission to be tested is respectively connected with a driving motor and a load motor, the driving motor is connected with an input shaft of the automatic transmission to be tested through an Oldham coupling, one side of an output shaft of the automatic transmission to be tested is connected with the load motor through a half shaft and a transition flange, the other side of the output shaft of the automatic transmission to be tested is connected with a fixed bracket through the half shaft and then is fixed on a test bench, an upper computer is respectively connected with the driving motor, the load motor and a monitor, and the upper computer sends control signals to the load motor and the driving motor in real time and is responsible for controlling and collecting data of the whole load system and the driving system; the load motor is used for simulating the load of the whole vehicle, and torque and rotation speed information is acquired through a torque and rotation speed sensor and is transmitted to the upper computer through an Ethercat network.

The invention has the beneficial effects that:

according to the testing method disclosed by the invention, the testing of the gear shifting cooperative control of the power assembly of the 2AMT transmission is decomposed into the driving motor mode switching test, the gear shifting executing mechanism and the TCU debugging test and the MCU and TCU cooperative control load test, so that the omnibearing detection of the gear shifting cooperative control performance of the power assembly of the electric drive 2AMT transmission can be realized, and the detection result is accurate and reliable.

The test system provided by the invention has a simple and reasonable structure, and is convenient and quick to test and operate.

Drawings

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

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

FIG. 3 is a schematic diagram of a specific control flow of a shift process according to an embodiment of the present invention;

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

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

Detailed Description

The following description of the embodiments of the present invention will be made apparent and complete in conjunction with the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the present invention.

An electric drive system of an electric vehicle, comprising: driving motor, driving Motor Controller (MCU), 2AMT automatic transmission body and Transmission Controller (TCU), before the actual vehicle test is performed, each component module needs to be debugged and calibrated in order to better match the vehicle. The bench test needs to prepare a connecting component needed by the test, match terminals connected by an electric appliance, arrange sensors needed by the test, debug a measurement and control system and the like in the early stage. The clutch-free gear shifting test realizes cooperative control of the driving motor and the transmission, and the process needs rapid switching of the driving motor between a rotating speed mode and a torque mode, accurate position control of a gear shifting executing 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 executing mechanism test, a TCU debugging test and a final cooperative control load test.

Test principle: when the electric vehicle is running normally, the driving motor is in a torque mode. In the gear shifting process, the driving motor needs to be regulated in speed, 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 from a torque driving mode to a free running mode, the torque at the input end of the transmission is zero, which is equivalent to the clutch release process of the manual transmission, and the gear shifting motor can smoothly drive the synchronizer to finish the gear removing operation. When the synchronizer is in a neutral position, the input shaft and the output shaft of the transmission are in a separated state, the input end of the transmission is connected with the driving motor, and the 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 basically keeps unchanged in the gear shifting process, and because the transmission ratio between the input shaft and the output shaft changes 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 the new gear. Thus, the operation mode of the drive motor will be switched from the free-running mode to the rotational speed mode. The rotation speed is automatically regulated by the driving motor, and the rotation speed difference of the driving part and the driven part of the synchronizer is reduced; after the motor speed regulation is completed, the working mode of the driving motor is changed from a rotating speed mode to a free running mode so that the automatic transmission can smoothly cut into a target gear for smooth gear engagement; 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 performs test on the gear shifting cooperative control of the electric drive 2AMT transmission power assembly of the electric vehicle, and can be disassembled into: and finally, performing test data processing to build a comprehensive test system for the gear shifting cooperative control of the power assembly of the electric drive 2AMT transmission.

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

In the novel power system of the driving motor +2amt, the driving motor needs to be controlled in different modes according to the gear shifting requirement due to the gear shifting process. In the whole gear shifting process, the driving motor mainly works in three modes: torque mode, free mode, and rotational 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 opening reflects the torque demand of the driver on the drive motor, which does not perform the 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 the original current becomes 0. At this time, the driving motor is in a free mode, and in the free mode, the driving motor freely rotates by self inertia and does not output torque to the outside.

(c) Rotational speed mode. At this time, the MCU performs the closed-loop control of the rotation speed of the driving motor, namely, the driving motor is rotated and regulated to be within a certain error range according to the expected rotation speed instruction.

In the invention, the selected driving motor is an alternating current asynchronous motor (IM), and is controlled by a vector control method and realized by a rotor magnetic field orientation mode. The basic idea is as follows: under the principle of unchanged magnetic potential and power, the mathematical model of the driving motor under the static ABC coordinate system is converted into the mathematical model under the two-phase rotating coordinate system by adopting orthogonal transformation through Clarke transformation and Park transformation.

In a two-phase rotating coordinate system d-q, the stator current vector of the asynchronous motor is decomposed into two direct current components i oriented according to the rotor magnetic field _d And i _q Wherein control i _d Corresponding to control of magnetic flux, control i _q Corresponding to control torque. Under the rotation coordinate system d-q, an asynchronous motor rotor flux linkage equation based on rotor magnetic field orientation control is as follows:

t in _r Is the rotor time constant, T _r ＝L _r /R _r ，i _sd Is the component of the stator current on the d-axis. It can be seen that the rotor flux linkage ψ _r With stator current component i _sd The first-order inertia links are arranged between the first-order inertia links. Thus, the exciting current is controlledi _sd The rotor flux linkage ψ 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 equal to the stator current q-axis component i _sq And rotor flux linkage psi _r Proportional to the ratio. Thus, by controlling i _sd And i _sq To control the electromagnetic torque of the drive motor. In the control of a conventional ac motor, the control is generally performed according to output characteristics of different phases of torque and rotational speed of the motor. When the rotation speed of the driving motor is lower than the base speed, the exciting current i is maintained _sd For nominal value, by adjusting i _sq To change the torque output and realize constant torque control; by adjusting the exciting current i when the rotation speed of the driving motor is above the base speed _sd Hold i _sd ·ω _r Constant, simultaneously regulating torque current i _sq And ensure T _e ·ω _r And (3) the field weakening control is realized by the constant.

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

In the rotating speed control mode, the MCU adjusts the target rotating speed of the rotating speed controller according to a speed regulation instruction given by the TCU, so that the output rotating speed of the driving motor can reach the designated rotating speed rapidly. In order to shorten the gear shifting time as much as possible, the speed regulation response of the driving motor is as fast as possible. In the rotation speed control, the MCU adopts the rotation speed closed-loop control to rapidly complete the speed regulation process.

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

The driving motor mode switching test process is as follows:

1.1, working before test: checking whether the mechanical connection of the components of the rack is complete; checking whether electric equipment has electric leakage or not and whether circuit connection has short circuit or not; checking whether each sensor can work normally or not;

1.2, waking up a power battery: firstly closing a relay, and adjusting the direct-current power supply voltage of the power battery to be increased to 330-350V;

1.3, MCU wake-up start: the gear of the 2AMT automatic transmission is respectively fixed at the gear I and the gear II, the opening of an accelerator pedal is regulated, and a driving motor is operated;

1.4, applying a rotating speed load to a load motor, adjusting the rotating speed and 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, a control platform monitoring system: the data acquisition is used for acquiring pedal opening rotating speed and torque signals of the driving motor through a CAN bus, and acquiring rotating speed and torque signals of the load motor through a rack torque meter and an encoder;

1.6, orderly power-off unloading after the test is ended: firstly, unloading a driving motor, closing a direct current power supply after a transmission system stops running, and stopping the machine after the bus voltage drops to be within 12V;

1.7, analysis of test data, repeated test for reliability assurance of test, each test was repeated 30 times.

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

The electric gear shifting executing system consists of a gear shifting executing mechanism and an executing motor, wherein the gear shifting executing mechanism comprises a brushless direct-current gear shifting motor, a worm gear reducing mechanism, a cam rotary drum, a gear shifting fork, a synchronizer, a neutral gear position sensor and the like, and the gear shifting executing motor adopts a high-performance rare earth permanent magnet brushless direct-current motor. The design objective of the electric gear shifting actuating mechanism is to realize accurate, reliable and quick gear shifting. The gear shifting technical performance indexes are as follows: shift stroke s=21 mm, shift force F >300N, shift time t <1s or tsmin. The Transmission Control Unit (TCU) of the electric drive 2AMT comprises a housing, a card board, a printed circuit board and a connector, wherein the most predominant component is a printed circuit board PCB, which integrated circuit board mainly comprises: the device comprises a power module, a rotating speed signal acquisition module, a position signal acquisition module, a switching 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. As shown in FIG. 1, a flow chart of a TCU control to complete a shift operation is shown in an embodiment of the invention. The gear shifting executing mechanism firstly receives a gear shifting instruction of the TCU to carry out neutral gear picking operation, and carries out synchronizer position feedback through a Hall signal of the gear shifting motor and a neutral gear position sensor to determine when the gear shifting executing mechanism 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 shifting operation, at the moment, whether the target gear is reached or not is determined through a Hall signal of the gear shifting motor, and meanwhile, the position information of the synchronizer is fed back to the TCU, so that the driving motor is controlled to recover the torque mode. The control of the shift actuator determines the shift time and shift reliability, and some control parameters of the shift execution need to be calibrated and optimized, so that bench tests related to the shift execution need to be designed.

The TCU is an electronic control unit of the 2AMT, and when receiving the output shaft rotating speed signal and the instruction sent by the MCU, the TCU controls the forward and reverse rotation of the gear shifting motor through the gear shifting logic to finish the gear shifting or gear shifting operation. To verify the control performance of the TCU, it is first necessary to verify the control performance of the TCU on the gear shift motor when no load is applied, and then shift tests are performed at different rotational speeds to prove the reliability of the shift process. And finally, driving the motor to drag the driving circulation working condition on the test bed, and simulating the actual road condition of the whole vehicle to realize the automatic upshift and downshift process under the actual working condition.

In the design process of the transmission of the electric drive 2AMT system, various key parameters of a gear system, such as the number of teeth and the reduction ratio of a main speed reducer, the number of teeth and the reduction ratio of gears of 1 gear and 2 gear, and the like, are required to be considered. Key parameters for transmission design of the resulting electrically driven 2AMT system are designed and optimized. When the various components of the transmission gear train, bearings, and housing are designed, it is desirable to consider the integrated assembly of the various sub-components. The electric drive 2AMT system needs to realize functions such as whole vehicle drive and gear shift control, and reasonable sensor configuration is needed to acquire required state information, so that the designed functions are realized stably.

The gear shifting strategy and the gear shifting rule are key contents of control of the electric drive 2AMT system, and the whole electric passenger car can be guaranteed to be compatible with power performance and economy through the design of the gear shifting rule. The shift control strategy is mainly implemented 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; collecting the accelerator pedal position, the gear position of the gearbox and the like of the whole vehicle through a position signal module; and a key switch, a brake signal and the like of the whole car are collected through a switch signal module. The TCU control function is used for comprehensively analyzing and calculating according to the collected rotating speed signals, position signals, switching signals and the like, judging the vehicle condition, the road surface condition, the intention of a driver and the gear shifting time, sending a control instruction to the driving module, simultaneously carrying out data transmission with the serial port communication module and the CAN communication module, receiving useful information of other controllers of the whole vehicle, and sending 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 gear shifting rule is divided into three types, namely dynamic, economical and comprehensive gear shifting rules. Consider that when the vehicle starts using a first gear, an upshift is not performed until the speed is less than 50 km/h. Meanwhile, in order to avoid that the working rotation speed of the power motor is higher for a long time under the condition of low-speed running of the vehicle, the downshift speed is not too low. And respectively performing a static state gear shifting test and a load gear shifting test in the bench test.

Static state shift test. And when the driving motor and the load motor are in a static state, the TCU controls the gear shifting executing motor to perform the cyclic gear lifting operation. Whether the synchronizer is in place or not is controlled according to the Hall position signal, accumulated errors caused by the Hall in the circulation process are corrected through the neutral gear position sensor, and the lifting gear operation is controlled through controlling the forward and reverse rotation of the gear shifting motor. The electrically driven 2AMT system can smoothly realize the gear shifting function under the static condition. The time occupied in the gear shifting process is about 1s, and gear shifting can be realized faster, so that the smooth running of the whole vehicle in the electric drive 2AMT driving process is ensured.

Load shift test. When the driving motor operates in a torque mode, the load motor operates in a rotating speed mode, and the electric drive 2AMT test bed simulates the whole running condition of the electric vehicle. The pedal opening is controlled to be equivalent to controlling 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 in a static state, the TCU controls the gear shifting executing motor to perform the cyclic gear lifting operation. Whether the synchronizer is in place or not is controlled according to the Hall signal of the gear shifting motor, accumulated errors caused by the Hall signal in the circulation process are corrected through the neutral position sensor, and the lifting gear operation is controlled through controlling the positive and negative rotation of the gear shifting motor.

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

2.1, the driving motor and the load motor are in a free state, the output half shaft is manually rotated, and the half shaft can be easily rotated to determine that the whole transmission system works normally;

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

2.3, after calibration is completed, starting to execute I gear up-II and II gear down-I gear tests for 50-100 cycles;

2.4, if the gear shifting motor is blocked, immediately disconnecting the 12V power supply, and recalibrating the number of turns of each gear position until the gear shifting motor is not blocked;

and 2.5, after the test is finished, recording accurate data of the number of turns from the neutral gear position to the first gear and the second gear, and further improving acceleration and deceleration of the motor and gear shifting smoothness in the gear shifting process.

MCU and TCU cooperative control load test, namely: 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 pedal opening information, and then carries out information interaction with the MCU to cooperatively complete the gear shifting process. To verify the shift performance of an automatic transmission, a TCU test is finally required. For smooth gear shifting, the TCU and the MCU are matched to work cooperatively. Thus, the information interaction between the TCU and the MCU is important. And a Controller Area Network (CAN) is the most widely used communication network in automobiles at present, so the invention adopts the CAN network to realize cooperative communication of the TCU and the MCU. In a 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 in gear shifting, data interaction is needed between the MCU and the TCU in real time so as to complete corresponding work of each stage of the gear shifting process, and the system is ensured to complete gear shifting smoothly and reliably.

The data interaction between the TCU and the MCU of the 2AMT system is completed by means of CAN messages, as shown in FIG. 2, which is a logic diagram of data interaction communication between the TCU and the MCU in the embodiment of the invention. The data interaction communication content between the TCU and the MCU comprises: message 0x1000A1B1, which represents that TCU sends out instruction of "shift start"; message 0x1001A1B1, which represents the TCU issuing a "complete gear" instruction; message 0x1002A1B1, which issues a "shift request" on behalf of the TCU; message 0x1003A1B1, which issues a "shift request" on behalf of the TCU; message 0x1004A1B1, which sends "transmission gear information" on behalf of TCU (once every 20 ms); message 0x1000B1A1 represents MCU to send out "torque is 0" information; message 0x10001B1A1 represents MCU to send out speed regulation completion instruction; message 0x1002B1A1, represents MCU reply "shift request"; message 0x1003B1A1 represents MCU to send out data such as driving motor rotation speed, pedal switch opening 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, message 1005A1B1 receives the information 0101799a, high byte 0x01 (hexadecimal), low byte 0x79 (hexadecimal), and the formula is calculated: shift motor turns= (256×hex2DEC (high byte) +hex2DEC (low byte))/24= (256×1+121)/24=15.7. At the moment, the number of turns of the gear shifting motor is 15.7, and the data of the number of turns of the gear shifting motor are cleared when the gear shifting/gear shifting action is completed once.

As shown in fig. 3, a specific control flow diagram of a gear shifting process according to an embodiment of the present invention is shown. In the whole process, the driving motor is switched from a torque mode to a free mode, then from the free mode to a rotating speed mode, then from the rotating speed mode to the free mode, and finally from the free mode to the torque mode. To realize the quick and reliable gear shifting process, the system is firstly debugged and calibrated in the mode switching process of the driving motor. Aiming at the existing driving motor and MCU, some control logic in the MCU needs to be modified to complete the instruction requirement of 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 2AMT automatic transmission is at a neutral gear or not, and whether the TCU supplies power normally or not;

and 3.2, electrifying a power battery: the high-voltage direct current of 350V is provided for the driving motor, the gear lever is used for setting the forward gear, the torque mode of the driving motor is provided, and the rotating speed mode of the load motor is provided.

3.3, controlling an accelerator pedal opening signal: increasing an opening signal, driving a motor to accelerate until the rotating speed passes over an upshift line, and completing upshift; and then controlling the pedal opening signal to reduce the pedal opening signal, so that the driving motor is decelerated, passes through a downshift line, and further realizes downshift operation. This is done for several cycles of the upshift and downshift operations.

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

4. And (5) test data processing.

4.1, graphic data post-processing and experimental reporting.

The test procedure measurement recorded data included: physical quantities such as motor torque and rotation speed collected by the rack torque meter and the rotation speed sensor, and data such as current and voltage recorded by the power meter. In the bench test process, in order to intuitively see the gear lifting process of the 2AMT, the data in the test are subjected to imaging processing, so as to obtain a schematic diagram of imaging processing of the test data in the embodiment of the invention shown in fig. 4. As can be seen from fig. 4, the time of 1 gear up is 187.4 seconds to 188 seconds, 0.6 seconds is used, the gear shifting motor rotates 20 circles, and the time of 2 gear up is 188.5 to 190.6, 1.1 seconds is used, which indicates that mechanical faults, such as unsmooth operation, or locked rotation, even mechanical blocking and the like, occur in the gear shifting process of the AMT speed changing system, and the problem of accumulating neutral gear position errors possibly exists in the gear shifting process is solved; in the one second process of 1 gear up-shifting and 2 gear up-shifting, the torque of the driving motor fluctuates between 0 and 80NM, the rotating speed is adjusted from 2600 to 1400, the speed and torque are reduced, and the fluctuation in the middle of 188.6 to 189 seconds also shows mechanical clamping stagnation in the initial process of 1-2 gear up-shifting. Through 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 successfully completed.

4.2 shift process optimization.

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

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

sequence number	Part name	Brand/model/specification
			1	Power battery and BMS thereof	Time-of-flight 350VDC
2	Power analyzer	Time wind
			3	Driving Motor Controller (MCU)	Shenzhen blue sea Hua Teng
4	Driving motor	Shandong Depuda three-phase asynchronous induction motor
			5	Two-speed transmission assembly	Time wind
6	Gear shifting motor	Changzhou multidimensional brushless DC motor 57ZWS601
			7	Transmission Controller (TCU))	Time wind
8	Low-speed load motor	Beijing Shenli measurement and control
			9	Torque and rotation speed sensor	Beijing Shenli measurement and control
10	Data acquisition device	Beijing Shenli measurement and control
			11	Upper computer and measurement and control software	Time wind

By using the test equipment in the table, the comprehensive test of the 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. A test system for gear shifting cooperative control of a 2AMT transmission power assembly comprises the following steps: the automatic transmission to be tested is a 2AMT automatic transmission, the 2AMT automatic transmission is respectively connected with a driving motor and a load motor, the driving motor is connected with an input shaft of the 2AMT automatic transmission through an Oldham coupling, one side of an output shaft of the 2AMT automatic transmission is connected with the load motor through a half shaft and a transition flange, and the other side of the output shaft of the 2AMT automatic transmission is connected with a fixed support through the half shaft so as to be fixed on a test bench. 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, a power battery provides 330V high-voltage direct current power supply for the MCU, and an MCU wiring terminal is connected with a power analyzer and can detect three-phase alternating 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 run under 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 rotation speed information is acquired through a torque and rotation speed sensor and is transmitted to the upper computer through an Ethercat network. The MCU and the TCU are connected 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 control the bench in real time by matching with a data board card of NI, and the graphical interface is more convenient according to the requirement of a user; the upper computer has a data analysis function, analyzes the data acquired by each CAN point, so as to obtain different data results, form different graphical curves and analyze the overall performance condition of the gear shift cooperative control of the power assembly of the 2AMT transmission.

Claims

1.2A test method for shift cooperative control of an AMT transmission power assembly is characterized by comprising the following steps: the driving motor mode switching test is used for 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 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 the TCU cooperatively 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, and problems of the TCU and the whole vehicle control are found through analysis of bench test results, so that reasons affecting gear shifting performance are analyzed from two aspects of mechanical structure design and control algorithm optimization;

in a gear shifting executing mechanism test and a TCU debugging test, calibrating and optimizing control parameters of gear shifting execution; the control performance of the TCU is verified, firstly, the control performance of the TCU on the gear shifting motor is verified under no load, and then gear shifting tests at different rotating speeds are carried out to prove the reliability of the gear shifting process; finally, simulating the actual road condition of the whole vehicle to realize the automatic upshift and downshift process under the actual working condition; when the actual road condition of the whole vehicle is simulated, a driving motor on a test bed drags a driving circulation working condition, and the actual road condition of the whole vehicle is simulated to realize automatic upshift and downshift processes under the actual working condition; the gear shifting control strategy is realized by a TCU, the TCU control function is to carry out comprehensive analysis and operation according to the collected rotating speed signal, position signal and switching signal, and judge the vehicle condition, road surface condition, driver intention and gear shifting time, thereby 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 rule is divided into three types, namely dynamic property, economy and comprehensive gear shifting rule, when the vehicle starts by using one gear, the gear shifting is not carried out until the speed is not up to 50km/h, and meanwhile, the working rotating speed of the power motor is high for a long time under the condition of avoiding low-speed running of the vehicle, and the gear shifting down speed is not too low; and respectively performing a static state gear shifting test and a load gear shifting test in the bench test.

2. The method for testing shift cooperative control of a 2AMT transmission powertrain according to claim 1, wherein in the drive motor mode switching test, the drive motor is operated in three modes during the shift: the method comprises the steps of determining output torque of a driving motor by receiving an opening value of an accelerator pedal in a torque mode, a free mode and a rotating speed mode by an MCU (micro control unit), wherein the driving motor does not perform speed closed-loop control; in the free mode, the MCU controls the stator current of the driving motor, and the driving motor freely rotates by the inertia of the driving motor and does not output torque to the outside; and the MCU performs rotating speed closed-loop control on the driving motor in a rotating speed mode.

3. The method for testing shift cooperative control of a 2AMT transmission powertrain according to claim 2, wherein the driving motor mode switching test procedure is as follows:

1.1, working before test: checking whether the mechanical connection of the components of the rack is complete; checking whether electric equipment has electric leakage or not and whether circuit connection has short circuit or not; checking whether each sensor can work normally;

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

1.7, each test was repeated 30 times.

4. The method for testing shift cooperative control of a 2AMT transmission powertrain according to claim 1, wherein the specific steps of performing a shift actuator test and a TCU debug test are as follows:

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

2.4, if the gear shifting motor is blocked, switching off a 12V power supply, and recalibrating the number of turns of each gear position until the gear shifting motor is not blocked;

5. The test method for shift cooperative control of a 2AMT transmission power assembly according to claim 1, wherein in the cooperative control load test of the MCU and the TCU, the TCU first determines shift timing according to the vehicle speed sensor and the pedal opening information, and then performs information interaction with the MCU to cooperatively complete a shift process; when the vehicle performs gear switching, data interaction is performed 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 is switched from the free mode to a rotating speed mode, then is switched from the rotating speed mode to the free mode, and finally is recovered from the free mode to the torque mode; the method is characterized in that the method realizes the rapidness and reliability of the gear shifting process, firstly, the system debugging and calibration are carried out on the mode switching process of the driving motor, the control logic in the MCU is modified to complete the instruction requirement of gear shifting, and meanwhile, the mode switching process of the driving motor is debugged and calibrated.

6. The method for testing shift cooperative control of a 2AMT transmission powertrain of claim 5, wherein the step of the MCU and TCU cooperative control load test is as follows:

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

3.3, controlling an accelerator pedal opening signal: increasing an opening signal, driving a motor to accelerate until the rotating speed passes over an upshift line, and completing upshift; then controlling the pedal opening signal to reduce the pedal opening signal so as to enable the driving motor to slow down and pass through the downshift line, thereby realizing downshift operation, and performing cyclic upshift operation;

7. The method for testing shift cooperative control of a 2AMT transmission powertrain according to claim 1, wherein data in the test is subjected to imaging processing; the cooperative communication of the TCU and the MCU is realized by adopting a CAN network, and the data interaction communication content between the TCU and the MCU comprises: 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 of 0 information, the MCU sends a speed regulating completion instruction, the MCU replies the gear shifting request, and the MCU sends driving motor rotating speed and pedal valve opening data.

8.2 test system for shift cooperative control of an AMT transmission powertrain, characterized in that the test method according to claim 1 is applied, comprising: the automatic 2AMT transmission to be tested is respectively connected with the driving motor and the load motor, the upper computer is respectively connected with the driving motor, the load motor and the monitor, and the upper computer 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 data; the load motor is used for simulating the load of the whole vehicle, and torque and rotation speed information is acquired through a torque and rotation speed sensor and is transmitted to the upper computer through an Ethercat network.

9. The test system for gear shifting cooperative control of the 2AMT transmission power assembly according to claim 8, wherein the drive motor is connected with 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 with 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 with the fixed support through the half shaft and is further fixed on the test bed, the drive motor is a three-phase asynchronous drive motor, the drive motor is connected with the MCU through a high-voltage copper wire, the power battery provides 330V of high-voltage direct current power for the MCU, the MCU terminal is connected with the power analyzer, and the MCU is connected with the TCU through a CAN.