CN109060369B - Distributed electric transmission system test method, device and rack - Google Patents

Abstract

The invention relates to a test method, device and bench for a distributed electric drive system. The method includes: acquiring real-time torque control instructions fed back by a controller of the entire vehicle under test; The real-time vehicle state parameters of the car; according to the real-time vehicle state parameters, the calculated wheel speed of each driving wheel is obtained; according to the calculated wheel speed, through the transmission ratio of the vehicle mechanical transmission system, inversely infer the expected output shaft end of the drive motor under test Rotating speed. The dynamometer is mechanically connected to the output shaft of the drive motor under test through a coupling to provide a distributed load for the system under test. According to the expected rotational speed, the rotational speed of each dynamometer of the test bench is controlled respectively, and then a real-time and accurate equivalent distributed load is generated at the output shaft end of each motor under test, so as to complete the dynamic operation of the distributed electric drive system in the loop. condition test.

Description

Test method, device and bench for distributed electric drive system

technical field

The invention relates to the field of distributed electric vehicle electric drive system in-loop testing, in particular to a distributed electric drive system testing method, device and bench.

Background technique

Distributed drive electric vehicle is a vehicle with a new type of drive that is produced with the electrification of automobiles. Functions such as steering electronic differential and driving force distribution can be realized through control strategies. This structure has outstanding advantages such as short driving transmission chain, high transmission efficiency and compact structure. In the early stage of system development, a corresponding test system is urgently needed to simulate the distributed dynamic load of the whole vehicle on the bench, so as to facilitate hardware-in-the-loop tests under various dynamic conditions, test the efficiency and energy consumption of the system, and verify the driving force. Assign control strategies, etc.

The electric drive system test benches currently on the market or granted patents are generally aimed at the traditional single-motor electric drive structure. For the test of distributed electric drive system, especially the special test bench that can accurately simulate the dynamic distributed load under the steering condition of the electric drive system is still very lacking. It is also an urgent need in the industry to be able to perform full-condition dynamic hardware-in-the-loop testing of distributed electric drive systems according to the standard operating conditions and standard trajectories in the test specification. Existing chassis dynamometers cannot meet this demand, and generally lack a distributed load dynamic simulation algorithm based on real-time calculation, and can only simulate equal load or complete static load test.

Therefore, how to calculate the distributed load in real time and perform dynamic simulation in the in-loop test of distributed drive electric vehicles is an urgent problem to be solved in the industry.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention provides a distributed electric drive system testing method, device and bench, the method calculates the target speed of each driving wheel in real time, controls the dynamometer, and generates real-time and accurate equivalent distributed load, Complete the dynamic condition test.

As a first aspect of the present invention, it relates to a method for testing a distributed electric drive system, comprising:

Obtain the real-time torque control command fed back by the controller of the vehicle under test;

Calculate the real-time vehicle state parameters of the distributed driving electric vehicle according to the torque control command; obtain the calculated wheel speed of each driving wheel according to the real-time vehicle state parameters;

According to the calculated wheel speed, through the transmission ratio of the mechanical transmission system of the vehicle, inversely infer the expected rotation speed of the output shaft end of the drive motor under test;

According to the expected rotational speed, the rotational speed of the dynamometer is controlled by the dynamometer controller, and an equivalent distributed load is generated at the output shaft end of the drive motor under test.

In one embodiment, before acquiring the real-time torque control command fed back by the vehicle controller under test, the method further includes:

Obtain preset path, working conditions and current vehicle state parameters, and generate simulated steering wheel angle signals and accelerator pedal signals;

Send the steering wheel angle signal and the accelerator pedal signal to the tested vehicle controller.

In one embodiment, the method further includes:

All test data of the distributed electric drive system are displayed in real time.

In one embodiment, calculating the real-time vehicle state parameters of the distributed driving electric vehicle according to the torque control instruction; obtaining the calculated wheel speed of each driving wheel according to the real-time vehicle state parameters; including:

According to the torque control command, each driving torque command _Te is obtained;

Substitute each driving torque command T _e into the dynamic transfer function _Ge-system of the distributed electric drive system and then go through the virtual vehicle model G _7-d-vehicle &G _tires to obtain the wheel speed ω _w of each driving wheel.

In one embodiment, according to the calculated wheel speed, through the transmission ratio of the mechanical transmission system of the vehicle, the expected rotational speed of the output shaft end of each of the tested drive motors is reversed; including:

According to the calculated wheel speed ω _w , through the transmission ratio G of the mechanical transmission system of the vehicle, according to formula 1, the expected rotational speed of the output shaft end of each drive motor to be tested is obtained

Formula one:

In one embodiment, according to the expected rotational speed, the dynamometer controller is used to control the rotational speed of the dynamometer, and an equivalent distributed load is generated at the output shaft end of the drive motor under test; including:

和各测功机的当前转速ω，对各测功机进行转速控制，根据公式二，产生等效的分布负载T_d；According to the expected speed

and the current rotational speed ω of each dynamometer, control the rotational speed of each dynamometer, and generate an equivalent distributed load T _d according to formula 2;

G_control为测功机转速PI控制的传递函数。Formula two:

G _control is the transfer function of the dynamometer speed PI control.

In one embodiment, the process of generating the simulated steering wheel angle signal and the accelerator pedal signal includes:

Simplify the running of the vehicle within the preset time as a uniform motion with a longitudinal motion speed of v _x , and a lateral motion as a uniform acceleration motion with an initial speed of v _y ;

设预期侧向偏差为y_p，根据牛顿运动定律计算得到预期侧向加速度

In the vehicle driving coordinate system, the expected trajectory is discretized into a point set to obtain the expected point

Let the expected lateral deviation be y _p , and calculate the expected lateral acceleration according to Newton's law of motion

Formula three:

Obtain the required steering wheel angle signal according to the lateral acceleration gain _Gay :

Formula four:

In formula 4, L is the wheelbase of the vehicle; C is the understeering parameter, C>0, i _steering is the steering transmission ratio, and δ _steering is the steering wheel angle;

Throttle opening Input is calculated by the following formula:

where Tr is the overall resistance transmitted to the vehicle drive motor; m is the vehicle mass; _g is the gravity constant; θ is the road gradient; f is the road rolling resistance coefficient; C _D is the air resistance coefficient; A is the vehicle windward area; 21.25 is a well-known constant, (to calculate wind resistance, the physical meaning is related to air density), dt is the time differential; v _x is the longitudinal speed of the vehicle; δ is the mass coefficient after considering the moment of inertia; η is the mechanical efficiency of the transmission system; G is Transmission ratio; R is the turning radius of the wheel; K _p , T _i and T _d are the parameters of the PID controller, sat(x) represents the saturation value; E is the speed error, and T _error is the motor drive torque required to correct the speed error and; T _max represents the sum of the maximum output torques of all the tested drive motors corresponding to the maximum throttle input at the current speed.

In a second aspect, the present invention also relates to a distributed electric drive system testing device, comprising:

The acquisition module is used to acquire the real-time torque control command fed back by the controller of the vehicle under test;

a calculation module, configured to calculate the real-time vehicle state parameters of the distributed driving electric vehicle according to the torque control instruction; obtain the calculated wheel speed of each driving wheel according to the real-time vehicle state parameter; according to the calculated wheel speed, pass The transmission ratio of the mechanical transmission system of the vehicle, inversely infers the expected speed of the output shaft end of the drive motor under test;

The control module is used to control the rotational speed of the dynamometer through the dynamometer controller according to the rotational speed, and generate an equivalent distributed load at the output shaft end of the drive motor under test.

In one embodiment, the apparatus further includes:

The generation module is used to obtain the preset path, working condition and current vehicle state parameters before obtaining the real-time torque control command fed back by the controller of the vehicle under test, and generate the simulated steering wheel angle signal and the accelerator pedal signal;

The sending module is used for sending the steering wheel angle signal and the accelerator pedal signal to the tested vehicle controller.

In one embodiment, the apparatus further includes: a display module for displaying all test data of the distributed electric drive system in real time.

In a third aspect, the present invention also relates to a test bench for a distributed electric drive system, comprising: a simulated battery pack, a distributed electric drive system under test, a distributed load simulation system, a data acquisition system and a bench control real-time system;

The simulated battery pack is electrically connected to the tested distributed electric drive system and the distributed load simulation system, respectively;

The tested distributed electric drive system includes: a tested vehicle controller, at least two tested motors and a tested motor controller; the tested vehicle controller controls the tested motor with the tested motor via the CAN bus. connected to the motor under test, and the motor controller under test is electrically connected with the motor under test;

The distributed load simulation system includes: the same number of dynamometers and dynamometer controllers as the motor under test, and the dynamometer is electrically connected to the dynamometer controller;

The output shaft of the motor under test is mechanically connected with the dynamometer through a coupling;

The data acquisition system is respectively connected in communication with the measured motor controller and the dynamometer controller;

The bench control real-time system is respectively connected with the tested vehicle controller and the dynamometer controller through the CAN bus;

The bench control real-time system includes the distributed electric drive system testing device according to any one of the above embodiments, and performs real-time control on the test bench to generate an equivalent distributed load.

In one embodiment, the simulated battery pack is electrically connected to the motor controller under test and the dynamometer controller, respectively;

The data acquisition system includes: a power analyzer, a voltage/current sensor and a torque/speed sensor;

The motor controller under test is connected with the motor under test through a three-phase wire, and the voltage/current sensor is installed on the three-phase wire according to the usage specification;

The output shaft of the motor under test is connected with the dynamometer through a coupling; the torque/speed sensor is installed between the dynamometer and the coupling;

The power analyzer is respectively connected in communication with the voltage/current sensor and the torque/rotation speed sensor, and receives signals from each sensor.

In one embodiment, it also includes: a monitoring host computer for displaying test data and inputting test instructions;

The monitoring host computer is respectively connected with the power analyzer and the gantry control real-time system.

In one embodiment, it further comprises: a gantry base;

The motor under test and the dynamometer are mounted on the stand base.

The beneficial effects of the above technical solutions provided by the embodiments of the present invention include at least:

A method for testing a distributed electric drive system provided by an embodiment of the present invention includes: acquiring a real-time torque control command fed back by a controller of a vehicle under test; and calculating a real-time vehicle for distributed driving of an electric vehicle according to the torque control command state parameters; according to the real-time vehicle state parameters, the calculated wheel speed of each driving wheel is obtained; according to the calculated wheel speed, through the transmission ratio of the mechanical transmission system of the vehicle, the expected speed of the output shaft end of the drive motor to be measured is inversely inferred; According to the expected speed, control the speed of the dynamometer controller, and generate an equivalent distributed load at the output shaft end of the drive motor under test. The distributed electric drive system testing method provided by the present invention calculates the real-time vehicle state parameters of the distributed driving electric vehicle under the real-time torque control signal by collecting and processing the real-time torque control signal fed back by the vehicle controller at high speed. , obtain each driving wheel to calculate the wheel speed, and inversely infer the speed of the output shaft end of the tested drive motor according to the transmission ratio of the mechanical transmission system of the vehicle. The output shaft end of the drive motor under test generates real-time and accurate equivalent distributed load to complete the dynamic condition test of the distributed electric drive system in the loop.

Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description, claims, and drawings.

The technical solutions of the present invention will be further described in detail below through the accompanying drawings and embodiments.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention. In the attached image:

Fig. 1 is the flow chart of the distributed electric drive system test method provided by the present invention;

2 is a block diagram of a distributed electric drive system test bench provided by the present invention;

3 is a structural diagram of a distributed electric drive system test bench provided by the present invention;

4 is a flowchart of a gantry control algorithm in the gantry control real-time system provided by the present invention;

5 is a block diagram of a distributed electric drive system testing device provided by the present invention;

Among them: 1-simulated battery pack, 2-distributed electric drive system under test, 21-vehicle controller under test, 22-motor under test, 23-motor controller under test, 3-distributed load simulation system, 31- Dynamometer, 32- Dynamometer Controller, 4- Data Acquisition System, 41- Power Analyzer, 42- Voltage/Current Sensor, 43- Torque/Rotation Speed Sensor, 5- Bench Control Real-Time System, 501- Generate Module, 502-sending module, 51-acquiring module, 52-calculating module, 53-controlling module, 54-displaying module, 6-monitoring upper computer, 7-bench base.

Detailed ways

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be more thoroughly understood, and will fully convey the scope of the present disclosure to those skilled in the art.

Embodiments of the present invention provide a method for testing a distributed electric drive system, which will be described below with reference to the accompanying drawings.

Referring to Figure 1, it includes the following steps:

S101. Obtain the real-time torque control command fed back by the controller of the vehicle under test;

S102. Calculate the real-time vehicle state parameter of the distributed driving electric vehicle according to the torque control instruction; obtain the calculated wheel speed of each driving wheel according to the real-time vehicle state parameter;

S103, according to the calculated wheel speed, through the transmission ratio of the mechanical transmission system of the vehicle, reversely infer the expected rotational speed of the output shaft end of the drive motor under test;

S104 , controlling the rotational speed of the dynamometer through the dynamometer controller according to the expected rotational speed, and generating an equivalent distributed load at the output shaft end of the drive motor under test.

In this embodiment, by collecting and processing the real-time torque control signal fed back by the vehicle controller at high speed, the real-time vehicle state parameters of the distributed driving electric vehicle under the real-time torque control signal are calculated, that is, the driving wheels are obtained. Calculate the wheel speed, and inversely deduce the expected speed of the output shaft end of the drive motor to be tested according to the transmission ratio of the vehicle mechanical transmission system. , and then generate a real-time and accurate equivalent distributed load at the output shaft end of the drive motor under test. The equivalent distributed load can be consistent with the dynamic distributed load that the electric drive system is subjected to when the distributed drive electric vehicle is actually driving, and can be used to realize distributed driving. In-the-loop dynamic condition test of electric drive system.

Further, referring to FIG. 1, before step S101, it also includes step: S100, including two sub-steps:

S1001, obtaining preset path, operating conditions and current vehicle state parameters, and generating a simulated steering wheel angle signal and an accelerator pedal signal;

S1002. Send the steering wheel angle signal and the accelerator pedal signal to the tested vehicle controller.

A method for testing a distributed electric drive system provided in this embodiment is based on a test bench, as shown in Figures 2 and 3, and is applied in the test of a distributed electric drive system to form a test closed loop including the hardware under test, which can be tested against the bench. The rack information is collected in real time, wherein steps S1001 and S102 to S104 are controlled in real time by means of a rack control algorithm. The gantry control algorithm is an equivalent distributed load simulation method based on model wheel speed tracking. This algorithm enables the distributed load simulation system to generate an equivalent dynamic distributed load and simulate the inertia and changing resistance of the distributed drive electric vehicle in actual driving.

In this embodiment, step S1001 generates an analog steering wheel angle signal according to the preset path, operating conditions and current vehicle state parameters through a preview follow method, and generates an accelerator pedal signal according to the vehicle speed error using a PID control method. In addition, on the basis of considering tire slip, side deflection and vehicle handling dynamics, steps S102 and S103 synchronously calculate the calculated wheel speed of each driving wheel of the distributed electric vehicle according to the torque control command of the vehicle controller, and then obtain the dynamometer engine speed target value.

Further, the method may further include: displaying all the test data of the above-mentioned distributed electric drive system in real time. During the test, all test data are displayed in real time, such as uploaded to the monitoring host computer, and visualized on the display interface. It makes the whole testing process more intuitive, and greatly improves the readability of the testing method and the friendliness of human-computer interaction.

A test method for a distributed electric drive system involved in the present invention, an applicable bench, as shown in FIGS. 2 and 3 , includes a simulated battery pack 1, a tested distributed electric drive system 2, a distributed load simulation system 3, A data acquisition system 4 with communication function, a gantry control real-time system 5 running the "people-vehicle-road" calculation model, a monitoring host computer 6, a gantry base 7 and mechanical connection components. The motor 22 under test and the dynamometer 31 are respectively fixed on the stand base 7 by bolts. The motor 22 under test is connected to one side of the torque/speed sensor 43 through a coupling, and the dynamometer 31 is arranged on the other side of the torque/speed sensor 43. In FIG. 3, the two motors 22 under test, the corresponding two Each dynamometer 31 constitutes a double rotary shaft system with two sets of motors paired tow, simulating the working state of the distributed electric drive system. The bench controls the real-time system 5, generates the analog steering wheel angle signal and the accelerator pedal signal, and sends them to the tested vehicle controller 21 through the CAN bus; the speed control command sent by the bench control real-time system 5 is sent to the dynamometer through the CAN bus. controller 32. The signals of the tested vehicle controller 21 and the dynamometer controller 32 are fed back to the bench control real-time system 5 through the CAN bus.

Taking a two-drive-wheel electric vehicle as an example, during the actual measurement, the operating conditions and target trajectory of this test are input in the bench test interface of the monitoring host computer 6, and the test is started. The above-mentioned "people-vehicle-road" calculation models include: steering driver model, 7-DOF dynamics model of distributed drive electric vehicle and Dugoff tire model. Vehicle state parameters, generate the analog steering wheel angle signal through the preview follow method, use the PID control method to generate the accelerator pedal signal according to the speed error, and input the generated driving control signals (steering wheel angle signal, accelerator pedal signal) together into the measured distributed power Transmission system 2. The vehicle under test controller 21 controls the electric drive system under test according to the input real-time driving control signal, for example, sends out respective torque control commands to the two distributed drive motor controllers, and feeds this signal back to the real-time gantry control system 5 in. Run the "people-vehicle-road" calculation kernel, synchronously calculate the calculated wheel speed of each driving wheel of the distributed electric vehicle, and then obtain the target value of the speed of each dynamometer 31, and synchronously refresh the vehicle state parameters in the above two models, upload Go to the display interface of the monitoring host computer 6 for visualization. The distributed drive type tested motor controller 23 performs torque control on the tested motor 22 according to the torque control command of the tested vehicle controller 21 , and the dynamometer controller 32 according to the respective rotational speed commands calculated by the bench control real-time system 5 , to control the speed of the dynamometer 31 to generate a real-time and accurate equivalent distributed load. The two sets of motors on the bench base 7 drag the rotary shaft system to operate according to the actual test conditions. The torque/speed sensor 43 collects the real-time speed and torque of the tested distributed electric drive system 2, and the voltage/current sensor 42 Collect real-time current and voltage, transmit each sensor signal to the power analyzer 41 for real-time calculation and display of mechanical power, electrical power, and efficiency, and upload it to the monitoring host computer 6 for visualization on the display interface of the monitoring host computer 6 .

As the path and working conditions change, the steering driver model in the "human-vehicle-road" computing kernel will simulate a real driver to generate steering wheel angle signals and pedal input signals, and the vehicle controller 21 under test will drive according to the steering wheel angle signal and pedal input signal. The force distribution algorithm distributes the driving force, and the test bench reads the control signal of the distributed driving force synchronously, and inputs it into the "people-vehicle-road" calculation model, which takes into account the vehicle dynamics and the interaction between the tire and the ground to estimate the vehicle The speed of the driving wheel at the next moment, and then the speed of the test simulation point is derived, and the speed of the dynamometer 31 is controlled. This algorithm uses the equivalent method to simulate the real distributed load of the distributed drive electric vehicle during the steering process. . At the same time, considering the actual situation of tire slippage, the saturation function limit of the maximum road adhesion is added to the speed loop of the internal speed control algorithm of the dynamometer controller 32, so that the generated equivalent distributed load will not exceed the actual road surface. Maximum adhesion to prevent distortion of load simulation. At the same time, because the bench load simulation algorithm is based on model feedforward control, the feedforward model prediction is carried out before the actual driving force output of the system under test is generated, which ensures the real-time performance of the load simulation, speeds up the response rate of the load simulation system, and makes the The hardware-in-the-loop test effect of the entire distributed electric drive system is closer to the real vehicle test.

The above-mentioned embodiment generates the simulated steering wheel angle signal through the preview following method, uses the PID control method to generate the accelerator pedal signal according to the vehicle speed error, and calculates the real-time equivalent distributed load. The specific calculation process is as follows:

当搜索方程成立时，所得P即为预瞄点。预期侧向偏差则为y_p，根据牛顿运动定律计算得到预期侧向加速度

Taking a vehicle with two driving wheels as an example, referring to Fig. 4, the driving of the vehicle in a short time (for example, within 1 second) is simplified as a uniform motion with a longitudinal motion speed of v _x , and a lateral motion with an initial speed of _vy . uniform acceleration motion. In the vehicle driving coordinate system, the expected trajectory is discretized into a series of coordinate points of point set S(x _k y _k )k=1, 2, 3..., starting from x _k = x ₁ according to the search equation (x _k -v _x T)(x _k+1 -v _x T)≤0Search, after judging the preview time T, the point on the expected trajectory closest to the arrival position of the vehicle

When the search equation is established, the obtained P is the preview point. The expected lateral deviation is y _p , and the expected lateral acceleration is calculated according to Newton's law of motion

The required steering wheel angle signal is obtained according to the lateral acceleration gain _Gay , where L is the wheelbase of the vehicle; C is the understeer parameter (C>0), i _steering is the steering transmission ratio, and δ _steering is the steering wheel angle.

The accelerator opening degree Input is calculated by the following formula.

where T _r is the overall resistance transferred to the vehicle; m is the vehicle mass; g is the gravity constant; θ is the road slope; f is the road rolling resistance coefficient; C _D is the air resistance coefficient; A is the vehicle windward area; Well-known constant, (to calculate wind resistance, the physical meaning is related to air density), dt is the time differential; v _x is the longitudinal speed of the vehicle; δ is the mass coefficient after considering the moment of inertia; η is the mechanical efficiency of the transmission system; G is the transmission ratio ; R is the turning radius of the wheel; K _p , T _i and T _d are the parameters of the PID controller, sat(x) represents the saturation value; E is the speed error, and T _error is the sum of the motor driving torque required to correct the speed error; T _max represents the maximum output torque sum of all the tested drive motors corresponding to the maximum accelerator input at the current speed.

In the above scheme, the designed vehicle dynamics model and Dugoff tire model take into account tire slip, side deflection and vehicle handling dynamics, and synchronously calculate the distributed distribution according to the torque control command of the vehicle controller 21 under test. Calculate the wheel speed of each driving wheel of the electric vehicle, and then obtain the target value of the rotational speed of the dynamometer 31 . The specific method is as follows:

Also taking a vehicle with two driving wheels as an example, referring to Fig. 4, the driving torque command T _e1 T _e2 is substituted into the dynamic transfer function _Ge-system of the distributed electric drive system, and then the virtual vehicle model G _{7-d -vehicle} &G _tires , get the theoretical wheel speed ω _w1 ω _w2 of the driving wheel.

即分布负载模拟系统的目标转速。The transmission ratio of the mechanical transmission components of the vehicle to be tested is G, and the expected rotational speed of the simulated reference point of the bench (ie: the output shaft end of the motor under test) can be obtained by pressing the formula (6).

That is, the target speed of the distributed load simulation system.

In the above solution, according to the current calculated wheel speed of each driving wheel calculated by the model, the target rotational speed of the dynamometer 31 is obtained, and the rotational speed of each dynamometer 31 is controlled to generate an equivalent distributed load T _d1 T _d2 .

为双测功机组的目标转速。G_control为测功机转速PI控制的传递函数。整个台架控制算法概括为基于轮速跟踪的等效分布负载模拟方法，可准确实时地模拟实际行驶中被测系统的真实负载。Taking Fig. 3 as an example, where ω ₁ ω ₂ is the actual rotational speed of the two dynamometers 31 (dynamometer 1 and dynamometer 2),

is the target speed of the double dynamometer unit. G _control is the transfer function of the dynamometer speed PI control. The whole gantry control algorithm is summarized as an equivalent distributed load simulation method based on wheel speed tracking, which can accurately and real-time simulate the real load of the system under test in actual driving.

In the above solution, as shown in FIG. 3 , each sensor has sufficient acquisition accuracy and can be used to test the dynamic operating conditions and instantaneous performance parameters of the distributed electric drive system 2 under test, the torque/speed sensor 43 and the voltage/current The sensor 42 transmits its signal to the power analyzer 41 for calculation and display of instantaneous mechanical power, electrical power and efficiency, and uploads it to the monitoring interface of the monitoring host computer 6 in real time for visualization. The gantry control real-time system 5 is based on the Xpc computing platform, and has the functions of real-time calculation and rapid control.

Based on the same inventive concept, the embodiment of the present invention also provides a distributed electric drive system test device and a test bench, because the principle of the problem solved by the test device and the test bench is the same as that of the distributed electric drive system in the foregoing embodiment. The test methods are similar, so the implementation of the test device and the test bench can refer to the implementation of the foregoing method, and the repetition will not be repeated.

In the second aspect, the following is a distributed electric drive system testing apparatus provided by an embodiment of the present invention, which can be used to execute the above-mentioned embodiment of the distributed electric drive system testing method.

Referring to Figure 5, a distributed electric drive system testing device includes:

an obtaining module 51, configured to obtain the real-time torque control command fed back by the controller of the vehicle under test;

The calculation module 52 is configured to calculate the real-time vehicle state parameter of the distributed driving electric vehicle according to the torque control instruction; obtain the calculated wheel speed of each driving wheel according to the real-time vehicle state parameter; according to the calculated wheel speed, Through the transmission ratio of the mechanical transmission system of the vehicle, the expected speed of the output shaft end of the drive motor under test is inferred;

The control module 53 is configured to control the rotational speed of the dynamometer through the dynamometer controller according to the expected rotational speed, and generate an equivalent distributed load at the output shaft end of the drive motor under test.

In one embodiment, the apparatus further includes:

The generating module 501 is used for obtaining preset path, working condition and current vehicle state parameters before obtaining the real-time torque control command fed back by the controller of the vehicle under test, and generating an analog steering wheel angle signal and an accelerator pedal signal;

The sending module 502 is configured to send the steering wheel angle signal and the accelerator pedal signal to the tested vehicle controller.

In one embodiment, the apparatus further includes: a display module 54 for displaying all test data of the distributed electric drive system in real time.

In the third aspect, referring to FIGS. 2 and 3 , an embodiment of the present invention further provides a distributed electric drive system test bench, which includes a simulated battery pack 1 , a tested distributed electric drive system 2 , a distributed load simulation system 3 , Data acquisition system 4 and gantry control real-time system 5 .

The above-mentioned simulated battery pack 1 is electrically connected to the measured distributed electric drive system 2 and the distributed load simulation system 3 respectively; the simulated battery pack 1 provides DC power, which is converted into three-phase AC power through the motor controller or dynamometer controller. Referring to FIG. 3 , two parallel solid lines (two different thicknesses) represent direct current, and three parallel solid lines represent three-phase alternating current.

Referring to FIG. 3 , the above-mentioned distributed electric drive system 2 under test includes: a vehicle-under-test controller 21 , at least two motors under test 22 and a motor-under-test controller 23 ; the vehicle-under-test controller 21 The motor controller 23 under test is connected to the motor controller 23 under test through the CAN bus, and the motor controller under test 23 is electrically connected to the motor under test 22 ; as shown in FIG. 3 , the dotted line and the arrow indicate the CAN bus.

The above-mentioned distributed load simulation system 3 includes: the same number of dynamometers 31 and dynamometer controllers 32 as the motor 22 under test, and the dynamometers 31 are connected to the dynamometer controller 32;

The output shaft of the above-mentioned motor under test 22 is connected to the dynamometer 31 through a torque/speed sensor 43 through a coupling;

The above-mentioned data acquisition system 4 is respectively connected in communication with the tested motor controller 23 in the tested distributed electric drive system 2 and the dynamometer controller 32 in the distributed load simulation system 3;

The bench control real-time system 5 is respectively connected with the tested vehicle controller 21 and the dynamometer controller 32 through the CAN bus, and is connected with the data acquisition system 4 through the monitoring host computer 6; the bench control real-time system 5 includes the above-mentioned The distributed electric drive system testing device of any one of the embodiments performs real-time control on the test bench to generate an equivalent distributed load.

In addition, this test bench can be suitable for the test of the electric drive system of the two-wheel drive, four-wheel or multi-wheel distributed drive electric vehicle. Extend the bench structure and set the corresponding number of dynamometers and dynamometer controllers. If high-power system testing is required, the power and bench size of the distributed load simulation system should be increased.

A distributed electric drive system test bench provided by the present invention forms a test closed loop including the tested hardware. Under the control of the bench control real-time system 5, the distributed load simulation system 3 can be the tested distributed electric drive system 2 . Deliver accurate, real-time dynamic workloads. The test bench monitors test data in real time, calculates real-time electrical power, mechanical power and efficiency, and displays real-time model calculation data.

The vehicle controller 21 under test sends a torque control command to the motor controller 23 under test. The motor under test 22 is torque controlled by the corresponding motor controller 23 under test, and the dynamometer 31 is controlled by the corresponding dynamometer controller 32 according to the speed command calculated by the bench control real-time system 5 for speed control. Each of the above controllers has a communication function.

Further; as shown in FIG. 3 , the above-mentioned data acquisition system 4 includes: a power analyzer 41 , a voltage/current sensor 42 , and a torque/speed sensor 43 ;

Wherein: the motor controller 23 under test is connected with the motor under test 22 through three-phase wires, and the voltage/current sensor 42 is installed on the three-phase wires according to the usage specification;

The output shaft of the motor 22 under test is connected to the dynamometer 31 through a coupling, wherein a torque/speed sensor 43 is also installed outside the coupling, and the dynamometer 31 is arranged on the other side of the torque/speed sensor 43 , when there are two motors 22 under test, a double rotary shaft system with two sets of motors paired tow is formed, simulating the working state of the distributed electric drive system.

The power analyzer 41 is respectively connected with the voltage/current sensor 42 and the torque/speed sensor 43;

The power analyzer 41 is connected with the monitoring host computer 6 through Ethernet; the monitoring host computer 6 further feeds back the real-time data of the gantry to the gantry control real-time system 5 .

In the above solution, the data acquisition system 4 has the functions of communication, monitoring and feedback. The real-time data of the gantry is sensed by each sensor, displayed on the monitoring host computer 6, and further fed back to the real-time gantry control system 5 to perform model synchronization operations and refresh the state of the gantry.

At the same time, the sensor signal is transmitted to the power analyzer 41 for calculation and display of instantaneous mechanical power, electrical power and efficiency; the gantry control signal sent by the gantry control real-time system 5 is transmitted through the CAN bus network, and the rotational speed command is sent to the dynamometer. controller 32. The real-time steering wheel angle signal and the accelerator pedal signal generated by the bench control real-time system 5 are sent to the vehicle controller 21 under test.

In this embodiment, based on a general real-time test platform, a set of real-time system is built, and the power analyzer is used to receive and process real-time sensor signals, which can realize real-time test of distributed electric drive system in any working condition and any path, and reflect the system under test. efficiency, verifying the functionality of the system under test.

Further, referring to Figures 2 and 4, all test data are uploaded to the monitoring host computer 6 in real time, and visualized on the display interface. It makes the whole testing process more intuitive, and greatly improves the readability of the testing system and the friendliness of human-computer interaction.

Referring to FIG. 3 , a bench base 7 is also included, wherein the motor 22 under test and the dynamometer 31 are respectively mounted on the bench base 7 through bolts.

In this embodiment, the gantry controls the real-time system 5 to generate an analog steering wheel angle signal, an accelerator pedal signal and a rotational speed control command, which are respectively sent to each node (such as the tested vehicle controller 21 and the dynamometer controller 32) through the CAN bus. ), and receive the feedback signal of each node through the CAN bus. The rotational speed/torque sensor data enters the power analyzer 41 and is fed back to the gantry control real-time system 5 through the monitoring host computer 6 .

Taking a two-drive-wheel electric vehicle as an example, during the actual measurement, the operating conditions and target trajectory of this test are input in the bench test interface of the monitoring host computer 6, and the test is started. The bench control real-time system 5 generates a simulated steering wheel angle signal and an accelerator pedal signal according to the preset path, operating conditions and current vehicle state parameters, and inputs them into the tested distributed electric drive system 2 . The vehicle controller 21 under test sends out respective torque control commands to the two distributed drive motor controllers according to the input real-time driving control signals (analog steering wheel angle signal and accelerator pedal signal), and feeds this signal back to the bench control real-time system 5 in. The calculated wheel speed of each driving wheel of the distributed electric vehicle is calculated synchronously, and then the target value of each dynamometer speed is obtained, and the vehicle state in the model is refreshed synchronously, and uploaded to the display interface of the monitoring host computer 6 for visualization. The distributed drive motor controller performs torque control on the motor under test 22 according to the torque control command of the vehicle controller, and the dynamometer controller 32 performs torque control on the dynamometer 31 according to the respective rotational speed commands calculated by the bench control real-time system 5 . Perform speed control to generate real-time and accurate equivalent distributed loads.

The two sets of motors on the bench base 7 drag the rotary shaft system to operate according to the actual test conditions. The torque/speed sensor 43 collects the real-time speed torque of the tested distributed electric drive system 2, and the voltage/current sensor 42 collects real-time current and voltage, transmits each sensor signal to the power analyzer 41 for real-time calculation and display of mechanical power, electrical power, and efficiency, and uploads it to the monitoring host computer 6 for visualization on the display interface.

As the path and working conditions change, the bench control real-time system 5 will simulate the real driver to generate the steering wheel angle signal and pedal input signal, and the tested vehicle controller will distribute the driving force according to its driving force distribution algorithm. The bench synchronously reads the control signal that distributes the driving force, and inputs it into the bench control real-time system 5. Considering the vehicle dynamics and the interaction between the tire and the ground, the driving wheel speed of the vehicle at the next moment is estimated, and then the derivation is made. The rotational speed of the test simulation point is obtained, and the rotational speed of the dynamometer 31 is controlled. This algorithm uses the equivalent method to simulate the real distributed load of the distributed drive electric vehicle during the steering process. At the same time, considering the actual situation of tire slippage, the saturation function limit of the maximum road adhesion is added to the speed loop of the internal speed control algorithm of the dynamometer controller 32, so that the generated equivalent distributed load will not exceed the actual road surface. Maximum adhesion to prevent distortion of load simulation. At the same time, because the bench load simulation algorithm is based on model feedforward control, the feedforward model prediction is carried out before the actual driving force output of the system under test is generated, which ensures the real-time performance of the load simulation, speeds up the response rate of the load simulation system, and makes the The hardware-in-the-loop test effect of the entire distributed electric drive system is closer to the real vehicle test.

For a distributed electric drive system test bench provided by the embodiment of the present invention, the specific algorithm involved may refer to the implementation in the above-mentioned distributed electric drive system test method, and repeated details will not be repeated. The test bench is designed for the hardware-in-the-loop test of the distributed electric vehicle electric drive system, which can provide dynamic distributed load for the distributed electric drive system. The dynamic state of the electric vehicle can be calculated in real time, and the rotational speed of each driving wheel can be estimated. Cooperate with the hardware of the test bench to realize the function test, algorithm verification and hardware-in-the-loop test of the electric drive system prototype in the R&D stage of distributed drive electric vehicle components.

Further, the equivalent distributed load simulation method based on wheel speed tracking control can accurately and real-time simulate the real road load received by each driving wheel of the distributed drive electric vehicle under different working conditions, which is the component level of the distributed electric drive system. System-level development experiments provide a virtual environment.

In addition, for the electronic differential steering control function of the distributed electric drive, when the tested distributed electric drive system 2 is two-wheel drive, the dual dynamometer system composed of the distributed load simulation system 3 can generate different rotational speeds and torques. A pair of loads can complete the test of the differential steering process of the distributed drive electric vehicle.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Thus, provided that these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims (10)

1. A distributed electric drive system test method is characterized by comprising the following steps:

acquiring a real-time torque control instruction fed back by the measured vehicle controller;

calculating real-time vehicle state parameters of the distributed driving electric vehicle according to the torque control instruction; obtaining the calculated wheel speed of each driving wheel according to the real-time vehicle state parameters;

according to the calculated wheel speed, the expected rotating speed of the output shaft end of the detected driving motor is reversely deduced through the transmission ratio of a mechanical transmission system of the vehicle;

according to the expected rotating speed, the rotating speed of the dynamometer is controlled through a dynamometer controller, and an equivalent distributed load is generated at the output shaft end of the tested driving motor;

according to the expected rotating speed, a dynamometer is controlled by a dynamometer controller, and an equivalent distributed load is generated at the output shaft end of the driving motor to be tested; the method comprises the following steps:

according to the expected rotating speed

And the current rotating speed omega of each dynamometer, the rotating speed of each dynamometer is controlled, and an equivalent distributed load T is generated according to a formula II_d；

The formula II is as follows:

G_controlthe transfer function is controlled by the rotating speed PI of the dynamometer.

2. The distributed electric drive system testing method according to claim 1, wherein before acquiring the real-time torque control command fed back by the tested vehicle controller, the method further comprises:

acquiring preset path, working condition and current vehicle state parameters, and generating a simulated steering wheel angle signal and an accelerator pedal signal;

and sending the steering wheel angle signal and the accelerator pedal signal to the tested vehicle control unit.

3. A method for distributed electric drive system testing as claimed in claim 2, wherein the method further comprises:

and displaying all test data of the distributed electric transmission system in real time.

4. A distributed electrical drive system testing apparatus, comprising:

the acquisition module is used for acquiring a real-time torque control instruction fed back by the measured vehicle control unit;

the calculation module is used for calculating real-time vehicle state parameters of the distributed driving electric vehicle according to the torque control instruction; obtaining the calculated wheel speed of each driving wheel according to the real-time vehicle state parameters; according to the calculated wheel speed, the expected rotating speed of the output shaft end of the detected driving motor is reversely deduced through the transmission ratio of a mechanical transmission system of the vehicle;

the control module is used for controlling the rotating speed of the dynamometer through a dynamometer controller according to the expected rotating speed and generating equivalent distributed load at the output shaft end of the tested driving motor;

the control module is used for controlling the motor according to the expected rotating speed

And the current rotating speed omega of each dynamometer, the rotating speed of each dynamometer is controlled, and an equivalent distributed load T is generated according to a formula II_d；

The formula II is as follows:

G_controlthe transfer function is controlled by the rotating speed PI of the dynamometer.

5. The distributed electric drive system test apparatus of claim 4, further comprising:

the generating module is used for acquiring preset paths, working conditions and current vehicle state parameters before acquiring a real-time torque control instruction fed back by the measured vehicle controller, and generating a simulated steering wheel corner signal and an accelerator pedal signal;

and the sending module is used for sending the steering wheel angle signal and the accelerator pedal signal to the measured vehicle control unit.

6. The distributed electric drive system test apparatus of claim 5, further comprising: and the display module is used for displaying all the test data of the distributed electric transmission system in real time.

7. A distributed electric drive system test bench comprising: the system comprises a simulation battery pack, a tested distributed electric transmission system, a distributed load simulation system, a data acquisition system and a rack control real-time system;

the simulation battery pack is electrically connected with the measured distributed electric transmission system and the distributed load simulation system respectively;

the measured distributed electric drive system comprises: the system comprises a tested vehicle controller, at least two tested motors and a tested motor controller; the tested vehicle controller is connected with the tested motor controller through a CAN bus, and the tested motor controller is electrically connected with the tested motor;

the distributed load simulation system includes: the dynamometer and the dynamometer controllers are the same in number as the tested motor, and the dynamometer is electrically connected with the dynamometer controller;

the output shaft of the tested motor is mechanically connected with the dynamometer;

the data acquisition system is respectively in communication connection with the tested motor controller and the dynamometer controller;

the rack control real-time system is respectively in communication connection with the whole vehicle controller to be tested and the dynamometer controller through a CAN bus;

the bench control real-time system comprises a distributed electric drive system test device according to any one of claims 4-5, and the test bench is controlled in real time to generate equivalent distributed load.

8. The distributed electric drive system test bench of claim 7 wherein said analog battery pack is electrically connected to said motor controller under test and said dynamometer controller, respectively;

the data acquisition system comprises: a power analyzer, a voltage-current sensor, and a torque-rotational speed sensor;

the tested motor controller is connected with the tested motor through a three-phase lead, and the voltage-current sensor is arranged on the three-phase lead;

the output shaft of the tested motor is connected with the dynamometer through a coupler; the torque-rotating speed sensor is arranged between the dynamometer and the coupling;

and the power analyzer is respectively in communication connection with the voltage-current sensor and the torque-rotating speed sensor and receives signals of the sensors.

9. The distributed electric drive system test rack of claim 8, further comprising: the monitoring upper computer is used for displaying test data and inputting test instructions;

and the monitoring upper computer is respectively connected with the power analyzer and the rack control real-time system.

10. A distributed electric drive system test rig according to any of claims 7-9, further comprising: a stage base;

the tested motor and the dynamometer are installed on the rack base.

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