Steering test bench and steering test method

Abstract

The embodiment of the invention discloses a steering test bench and a steering test method. The steering test bench comprises a front axle steering unit, a rear axle steering unit, a road feeling feedback system and a data processing system. In the first state, the front axle steering unit, the rear axle steering unit and the road feeling feedback system are coupled to form a four-wheel steering test system. In the second state, the front axle steering unit and the road feeling feedback system are coupled to form a front axle steering test system; and in the third state, the rear axle steering unit is coupled with the road feeling feedback system to form a rear axle steering test system. The data processing system is configured to obtain test data of the four-wheel steering test system, the front axle steering test system or the rear axle steering test system. The steering test bench facilitates verification of functions and strategies of vehicle drive-by-wire four-wheel steering, the bench is convenient to adjust, the front axle steering unit and the rear axle steering unit adopt a decoupling design, and the steering test bench can be suitable for test verification tests of various types of steering systems.

Description

Technical Field

[0001] The invention relates to the technical field of automobile testing, and in particular to a steering test bench and a steering test method. Background Art

[0002] The steer-by-wire system eliminates the mechanical connection between the steering wheel and the steering gear, and uses bus technology and related sensors to transmit relevant signals of the car. It has many advantages and is more in line with the development needs of intelligent cars. At the same time, compared with front-wheel steering cars, four-wheel steering vehicles with rear-wheel steering have better flexibility and handling stability due to different steering characteristics at low and high speeds. Therefore, steer-by-wire four-wheel steering has also been increasingly studied and applied, and it is particularly important to verify the functions and strategies of the system during the development of steer-by-wire four-wheel steering.

[0003] There are two types of steering test methods in related technologies. One is virtual development technology, which can reduce the development cycle and development cost. The advantage of using simulation software to verify functions and control strategies is that the simulation results are highly visualized and the parameters are easy to adjust. However, the actual steering system mechanical structure error, steering actuator working capacity, sensor sampling error and other factors are not taken into account in the test and verification of functions and strategies. The real-time performance of functional strategies and the actual working status of actuators are not easy to guarantee. The other is to use real vehicles for verification testing, but it requires a large cost and has higher requirements for the security and real-time performance of algorithm strategies.

[0004] Therefore, there is an urgent need for a steering test bench and a steering test method. Summary of the invention

[0005] The technical problem to be solved by the present invention is to simulate various simulation working conditions of a real vehicle under the premise of including actual execution components such as a steering trapezoidal structure and a steering motor but not relying on the chassis system of the entire vehicle, and to be able to directly monitor the action of the steering system and perform parameter modification settings, thereby reducing the test cost while improving its applicability and making installation and modification more convenient.

[0006] The embodiment of the present invention discloses a steering test bench, which includes:

[0007] A steering execution system, including a front axle steering unit and a rear axle steering unit;

[0008] The data processing system comprises a data acquisition module and a data processing module, wherein the data acquisition module is used to obtain vehicle state parameters and actual feedback parameters of the steering execution system; the data processing module is used to determine the expected feedback angle based on the vehicle state parameters and a first preset calculation model; and is also used to determine the vehicle handling stability state parameters based on the vehicle state parameters and the actual feedback parameters;

[0009] Among them, the steering execution system performs work according to the expected feedback angle. In a first state, the front axle steering unit, the rear axle steering unit and the data processing system are coupled to form a four-wheel steering test system; in a second state, the front axle steering unit and the data processing system are coupled to form a front axle steering test system; in a third state, the rear axle steering unit and the data processing system are coupled to form a rear axle steering test system.

[0010] Furthermore, the steering test bench also includes a road feel feedback system, which includes a road feel actuator motor, a steering wheel and a controller. The road feel actuator motor is connected to the steering wheel, and the controller is configured to control the road feel actuator motor to output feedback torque to the steering wheel.

[0011] Furthermore, the vehicle state parameters include at least an input angle of the steering wheel, and the data acquisition module includes a first angle sensor and a first torque sensor; the first angle sensor is installed in the road feel feedback system and is configured to detect the input angle of the steering wheel; the first torque sensor is installed in the road feel feedback system and is configured to detect the actual feedback torque of the steering wheel.

[0012] Furthermore, the steering wheel includes a wheel body and a column, and the first rotation angle sensor and the first torque sensor are both mounted on the column and are coaxially arranged with the column.

[0013] Furthermore, the road sense feedback system also includes a first reducer, and the road sense actuator motor is connected to the steering wheel via the first reducer.

[0014] Furthermore, the front axle steering unit includes a front axle actuator motor, a front axle steering trapezoidal structure and a front axle steering wheel, the front axle actuator motor is connected to the front axle steering trapezoidal structure, and the front axle steering trapezoidal structure is connected to the front axle steering wheel; the rear axle steering unit includes a rear axle actuator motor, a rear axle steering trapezoidal structure and a rear axle steering wheel, the rear axle actuator motor is connected to the rear axle steering trapezoidal structure, and the rear axle steering trapezoidal structure is connected to the rear axle steering wheel.

[0015] Furthermore, the data acquisition module also includes a pulling pressure sensor and a second angle sensor. The pulling pressure sensor is installed on the front axle steering unit and / or the rear axle steering unit, and is configured to detect the pulling pressure of the front axle steering trapezoidal structure and / or the rear axle steering trapezoidal structure; the second angle sensor is installed on the front axle steering unit and / or the rear axle steering unit, and is configured to detect the output angle of the front axle actuator motor and / or the rear axle actuator motor.

[0016] Furthermore, the front axle steering trapezoidal structure includes a front axle steering gear, a front axle universal joint and a front axle steering rod, and the front axle steering gear is connected to the front axle steering rods on both sides through the front axle steering knuckle; the rear axle steering trapezoidal structure includes a rear axle steering gear, a rear axle universal joint and a rear axle steering rod, and the rear axle steering gear is connected to the rear axle steering rods on both sides through the rear axle steering knuckle.

[0017] Furthermore, the data acquisition module also includes a displacement sensor installed on the front axle steering gear and / or the rear axle steering gear, and the displacement sensor is configured to detect the screw displacement of the front axle steering gear and / or the rear axle steering gear.

[0018] Furthermore, the front axle steering unit also includes a front axle resistance loading module, the front axle steering trapezoidal structure is connected to the front axle resistance loading module, and the front axle resistance loading module is configured to provide wheel-end resistance when the front axle steering wheel rotates; and / or, the rear axle steering unit also includes a rear axle resistance loading module, the rear axle steering trapezoidal structure is connected to the rear axle resistance loading module, and the rear axle resistance loading module is configured to provide wheel-end resistance when the rear axle steering wheel rotates.

[0019] Furthermore, the front axle steering unit also includes a front axle steering knuckle, which is fixedly connected to the front axle steering wheel, and the front axle steering trapezoidal structure is connected to the front axle resistance loading module through the front axle steering knuckle; and / or, the rear axle steering unit also includes a rear axle steering knuckle, which is fixedly connected to the rear axle steering wheel, and the rear axle steering trapezoidal structure is connected to the rear axle resistance loading module through the rear axle steering knuckle.

[0020] Furthermore, the front axle resistance loading module and the rear axle resistance loading module have the same structure, and both include a magnetic powder brake and a second reducer, the magnetic powder brake is connected to the second reducer, and the output shaft of the second reducer is connected to the front axle steering trapezoidal structure through the front axle steering knuckle; or the output shaft of the second reducer is connected to the rear axle steering trapezoidal structure through the rear axle steering knuckle.

[0021] Furthermore, the steering test bench also includes a support frame, and the front axle steering unit and the rear axle steering unit are both installed on the support frame.

[0022] The embodiment of the present invention further discloses a steering test method, which is applied to the above-mentioned steering test bench and includes the following steps:

[0023] Get vehicle status parameters;

[0024] Based on the vehicle state parameter and according to a first preset calculation model, determining a desired feedback angle;

[0025] Based on the expected feedback angle, control the front axle steering unit and / or the rear axle steering unit to operate;

[0026] Obtain actual feedback parameters of the steering execution system;

[0027] Based on the vehicle state parameter and the actual feedback parameter, a vehicle handling stability state parameter is determined.

[0028] Furthermore, the vehicle state parameters include a steering wheel input angle and a steering wheel rotation time, the actual feedback parameters include a wheel rotation angle and a wheel rotation time, and the vehicle handling stability state parameters include control accuracy and real-time performance.

[0029] Further, determining the vehicle handling stability state parameter based on the vehicle state parameter and the actual feedback parameter includes:

[0030] Determining the control accuracy based on the difference between the steering wheel input angle and the wheel rotation angle;

[0031] The real-time performance is determined based on the difference between the steering wheel rotation time and the wheel rotation time.

[0032] Furthermore, the method further comprises the following steps:

[0033] Based on the first angle sensor, acquiring the steering wheel input angle;

[0034] Based on the steering wheel input angle, determining a desired feedback torque of the steering wheel according to a second preset calculation model;

[0035] Based on the desired feedback torque, controlling the road sense execution motor to work;

[0036] Based on the first torque sensor, obtaining an actual feedback torque of the steering wheel;

[0037] Based on the expected feedback torque and the actual feedback torque, a signal closed loop of the road feel feedback system is formed to verify the accuracy of the road feel feedback system when it is in a working state.

[0038] Furthermore, the method further comprises the following steps:

[0039] Based on the steering wheel input angle, determining an expected steering resistance torque according to a third preset calculation model;

[0040] Based on the expected steering resistance torque, the front axle resistance loading module and / or the rear axle resistance loading module are controlled to operate.

[0041] Furthermore, the method further comprises the following steps: based on the pulling and pressure sensor, the second angle sensor and the displacement sensor, respectively obtaining the pulling and pressure of the front axle steering trapezoidal structure and / or the rear axle steering trapezoidal structure, the output angle of the front axle actuator motor and / or the rear axle actuator motor, and the screw displacement of the front axle steering gear and / or the rear axle steering gear;

[0042] Based on the expected steering resistance torque, the pulling force, the output angle and the lead screw displacement, a signal closed loop of the steering execution system is formed to verify the stability of the steering execution system when it is in a working state.

[0043] The steering test bench and steering test method of the present invention have the following beneficial effects, including but not limited to:

[0044] 1) The steering test bench includes the actual execution components such as the steering trapezoidal structure and the steering motor, but does not rely on the vehicle chassis system. Through the communication between the bench and external devices such as computers, it can simulate various simulation conditions of the real vehicle, and can directly monitor the action of the steering system and modify parameters. At the same time, the bench solution has low implementation cost, strong applicability, and convenient installation and modification.

[0045] 2) The steering test method can take into account factors such as the actual steering system mechanical structure error, steering actuator working capacity, sensor sampling error, etc. in the test and verification of functions and strategies, and the real-time performance of functional strategies and the actual working status of actuators can be guaranteed;

[0046] 2) The steering test method forms a closed-loop control circuit, which is more conducive to judging the accuracy of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0048] Figure 1 A schematic diagram of the structure of a steering test bench provided in an embodiment of the present invention;

[0049] Figure 2 A top view of a steering test bench provided in an embodiment of the present invention;

[0050] Figure 3 A side view of a steering test bench provided by an embodiment of the present invention;

[0051] Figure 4 A schematic diagram of the structure of a road sense feedback system provided by an embodiment of the present invention;

[0052] Figure 5A schematic structural diagram of a front axle steering unit provided by an embodiment of the present invention;

[0053] Figure 6 A schematic diagram of the structure of a front axle resistance loading module provided by an embodiment of the present invention;

[0054] Figure 7 A principle system block diagram of a steering test bench provided by an embodiment of the present invention;

[0055] Figure 8 A test logic block diagram of a steering test bench provided by an embodiment of the present invention;

[0056] Fig. 9 A logic block diagram of the joint simulation of the steering test bench and the driving simulator provided in an embodiment of the present invention;

[0057] Fig.10 A flow chart of a steering test method provided in an embodiment of the present invention.

[0058] Icons: 1-support frame; 2-magnetic powder brake; 3-second reducer; 4-kingpin; 5-front axle steering knuckle; 6-front axle steering wheel; 7-pull pressure sensor; 8-front axle steering trapezoidal structure; 9-front axle actuator motor; 10-front axle steering gear; 11-road sense actuator motor; 12-first reducer; 13-first steering angle sensor; 14-first torque sensor; 15-steering wheel; 16-rear axle steering gear; 17-rear axle actuator motor; 18-rear axle steering trapezoidal structure. DETAILED DESCRIPTION

[0059] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of this specification. For ordinary technicians in this field, this specification can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0060] It should be understood that the "system", "device", "unit" and / or "module" used herein are a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0061] As shown in this specification and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0062] Flowcharts are used in this specification to illustrate the operations performed by the system according to the embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed precisely in order. Instead, the steps may be processed in reverse order or simultaneously. At the same time, other operations may also be added to these processes, or one or more operations may be removed from these processes.

[0063] Example

[0064] Please refer to Figure 1-Figure 3 , this embodiment provides a steering test bench, the steering test bench includes a steering execution system, including a front axle steering unit and a rear axle steering unit; a data processing system, including a data acquisition module and a data processing module, the data acquisition module is used to obtain vehicle state parameters, and is also used to obtain actual feedback parameters of the steering execution system; the data processing module is used to determine the expected feedback angle based on the vehicle state parameters and the first preset calculation model; and is also used to determine the vehicle handling stability state parameters based on the vehicle state parameters and the actual feedback parameters; wherein the steering execution system performs work according to the expected feedback angle, in a first state, the front axle steering unit, the rear axle steering unit and the road sense feedback system are coupled to form a four-wheel steering test system; in a second state, the front axle steering unit is coupled to the road sense feedback system to form a front axle steering test system; in a third state, the rear axle steering unit is coupled to the road sense feedback system to form a rear axle steering test system. It can be understood that the data acquisition module and the data processing module can be connected by a controller area network (CAN) bus communication, or by a LIN bus or the like. wherein the data processing module can be a computer, a tablet or other device.

[0065] It is worth mentioning that the steering test bench is convenient for verifying the function and strategy of the vehicle's four-wheel steering by wire. The bench is easy to adjust. The front axle steering unit and the rear axle steering unit adopt a decoupled design, which can be applied to various forms of steering system test verification tests, such as the front wheel single-wire steering system test verification (i.e., in the second state, the front axle steering unit is coupled with the road sense feedback system to form a front axle steering test system); another example is the rear wheel single-wire steering system test verification (i.e., in the third state, the rear axle steering unit is coupled with the road sense feedback system to form a rear axle steering test system); another example is the four-wheel wire steering system test verification (i.e., in the first state, the front axle steering unit, the rear axle steering unit and the road sense feedback system are coupled to form a four-wheel steering test system). Compared with the actual vehicle test, the steering test bench has the advantages of simple structure, easy adjustment, convenient testing, and high applicability.

[0066] In this embodiment, the front axle steering unit includes a front axle actuator motor, a front axle steering trapezoidal structure and a front axle steering wheel, the front axle actuator motor is connected to the front axle steering trapezoidal structure, and the front axle steering trapezoidal structure is connected to the front axle steering wheel; the rear axle steering unit includes a rear axle actuator motor, a rear axle steering trapezoidal structure and a rear axle steering wheel, the rear axle actuator motor is connected to the rear axle steering trapezoidal structure, and the rear axle steering trapezoidal structure is connected to the rear axle steering wheel.

[0067] It is also worth mentioning that the steering test bench includes actual execution components such as the steering trapezoidal structure and the steering motor, but does not rely on the vehicle chassis system. The data obtained through the data acquisition module can simulate various simulation conditions of the real vehicle through communication between the bench and external devices such as computers, and can directly monitor the action of the steering system and modify parameters.

[0068] It is also worth noting that the data processing module can also be configured to control the operation of the front axle resistance loading module and / or the rear axle resistance loading module according to the input angle of the steering wheel 15. In a specific working environment, the input angle can be used only as a vehicle state parameter, based on the wire-controlled four-wheel steering vehicle model (i.e., the third preset calculation model), to output the expected steering resistance torque, thereby controlling the operation of the front axle resistance loading module and / or the rear axle resistance loading module. Depending on the specific implementation environment, one or a combination of simulated road conditions (for example, simulated road friction coefficient), the current vehicle speed and the input angle can also be used as input features to output the steering resistance torque, thereby controlling the operation of the front axle resistance loading module and / or the rear axle resistance loading module.

[0069] Please refer again Figure 1The steering test bench also includes a support frame 1, and the front axle steering unit and the rear axle steering unit are both installed on the support frame 1. It can be understood that the steering test bench is, from left to right (from left to right in the figure), the front axle steering unit, the road feedback system, and the rear axle steering unit, all of which are mainly supported by the support frame 1 of the aluminum profile, and corresponding flanges and other supporting parts are designed for each actuator, sensor and other components, which are fastened to the aluminum profile by bolts. The support frames 1 are fixed by connecting parts, which is convenient for installation and disassembly, and then it is convenient to adjust the layout size of the steering trapezoidal structure, so it is highly applicable to steering tests of different sizes.

[0070] like Figure 4 As shown, the data acquisition module includes a first angle sensor 13 and a first torque sensor 14; the first angle sensor 13 is installed in the road feel feedback system and is configured to detect the input angle of the steering wheel 15; the first torque sensor 14 is installed in the road feel feedback system and is configured to detect the actual feedback torque of the steering wheel 15.

[0071] In this embodiment, the steering wheel 15 includes a wheel body and a column. The first rotation angle sensor 13 and the first torque sensor 14 are both mounted on the column and are coaxially arranged with the column.

[0072] In this embodiment, the steering test bench also includes a road feel feedback system, which includes a road feel actuator motor, a steering wheel and a controller. The road feel actuator motor is connected to the steering wheel. The controller is configured to control the road feel actuator motor to output feedback torque to the steering wheel. The road feel feedback system also includes a first reducer 12, and the road feel actuator motor 11 is connected to the steering wheel 15 through the first reducer 12.

[0073] It is worth noting that the output shaft of the road sense actuator motor 11 is connected to the disc body and the pipe column through the first reducer 12 and the corresponding support, and is fixed to the aluminum profile through the designed flange. The output torque of the road sense actuator motor 11 is controlled, and the torque is decelerated and increased through the first reducer 12 to output the feedback torque to the steering wheel 15.

[0074] It is also worth noting that the first angle sensor 13 and the first torque sensor 14 are coaxial with the steering wheel 15, and corresponding support members are designed to be fixed on the aluminum profile. The first angle sensor 13 obtains the angle signal input by the steering wheel 15, and the first torque sensor 14 obtains the signal of the actual feedback torque of the steering wheel 15, so as to verify the subjective feeling of the steering road feel of the test personnel during operation.

[0075] Please refer to Figure 5The data acquisition module includes a pulling pressure sensor 7 and a second angle sensor. The pulling pressure sensor 7 is installed on the front axle steering unit and / or the rear axle steering unit, and is configured to detect the pulling pressure of the front axle steering trapezoidal structure 8 and / or the rear axle steering trapezoidal structure 18; the second angle sensor is installed on the front axle steering unit and / or the rear axle steering unit, and is configured to detect the output angle of the front axle actuator motor 9 and / or the rear axle actuator motor 17.

[0076] In this embodiment, the front axle steering unit also includes a front axle resistance loading module, the front axle steering trapezoidal structure is connected to the front axle resistance loading module, and the front axle resistance loading module is configured to provide wheel-end resistance when the front axle steering wheel rotates; and / or, the rear axle steering unit also includes a rear axle resistance loading module, the rear axle steering trapezoidal structure is connected to the rear axle resistance loading module, and the rear axle resistance loading module is configured to provide wheel-end resistance when the rear axle steering wheel rotates.

[0077] In this embodiment, the front axle steering trapezoidal structure 8 includes a front axle steering gear 10, a front axle universal joint and a front axle steering tie rod, and the front axle steering gear 10 is connected to the front axle steering tie rods on both sides through the front axle steering knuckle 5; the rear axle steering trapezoidal structure 18 includes a rear axle steering gear 16, a rear axle universal joint and a rear axle steering tie rod, and the rear axle steering gear 16 is connected to the rear axle steering tie rods on both sides through the rear axle steering knuckle; the data acquisition module also includes a displacement sensor installed on the front axle steering gear 10 and / or the rear axle steering gear 16, and the displacement sensor is configured to detect the lead screw displacement of the front axle steering gear 10 and / or the rear axle steering gear 16. It can be understood that the front axle actuator motor 9 is connected to the front axle steering gear 10 through a belt, and the rotation output by the front axle actuator motor 9 is transmitted to the lead screw nut in the steering gear through the belt, and then converted into lead screw displacement motion by the ball screw. The front axle steering gear 10 is connected to the front axle steering tie rods on the left and right sides through the front axle universal joint, thereby forming a front axle steering trapezoidal structure 8; by controlling the output angle of the front axle actuator motor 9, the displacement of the lead screw of the front axle steering gear 10 is controlled, thereby driving the movement of the front axle steering trapezoidal structure 8. Similarly, the connection relationship between the rear axle steering trapezoidal structure 18 and the rear axle actuator motor 17 is the same.

[0078] It is also worth mentioning that the tension pressure sensor 7 installed on the front axle steering rod can monitor the tension pressure on the front axle steering rod during steering, and is used to calibrate the resistance torque of the front axle resistance loading module.

[0079] In this embodiment, the front axle steering unit further includes a front axle steering knuckle 5, which is fixedly connected to the front axle steering wheel 6, and the front axle steering trapezoidal structure 8 is connected to the front axle resistance loading module through the front axle steering knuckle 5. It can be understood that the front axle steering trapezoidal structure 8 forms a revolving pair with the front axle steering knuckle 5 through a pin key, and the front axle steering knuckle 5 is fixedly connected to the front axle steering wheel 6. The movement of the front axle steering trapezoidal structure 8 will drive the front axle steering knuckle 5 to rotate around the kingpin 4 (i.e., the output shaft of the second reducer 3), simulating the rotation of the tire.

[0080] Please refer to Figure 6 , Figure 6 A schematic diagram of the structure of the front axle resistance loading module provided in an embodiment of the present invention. The front axle resistance loading module in this embodiment includes a magnetic powder brake 2 and a second reducer 3, the magnetic powder brake 2 is connected to the second reducer 3, and the output shaft (i.e., the kingpin 4) of the second reducer 3 is connected to the steering trapezoidal structure through the front axle steering knuckle 5.

[0081] It is worth noting that the input end of the second reducer 3 is matched with the output shaft end of the magnetic powder brake 2 by a key connection, and the output torque of the magnetic powder brake 2 acts on the kingpin 4 after being decelerated and torque-increased by the second reducer 3. The output shaft of the magnetic powder brake 2 passes through the second reducer 3 and forms a rotating pair with the front axle steering knuckle 5 through the kingpin 4. When the front axle actuator motor 9 rotates, it drives the input shaft of the front axle steering gear 10 to rotate, and the steering rack drives the front axle steering trapezoidal structure 8 to move, so that the front axle steering knuckle 5 overcomes the resistance torque and rotates around the kingpin 4.

[0082] It is also worth noting that the magnetic powder brake 2 and the second reducer 3 are used as the front axle resistance loading module in this embodiment. Specifically, the magnetic powder brake 2 is used to simulate the steering resistance of the wheels during the driving of the actual vehicle. The solution is simple, does not rely on the chassis system of the actual vehicle, and simulates the actual working conditions of the steering system to a high degree. Depending on the specific implementation environment, the magnetic powder brake 2 can also be replaced with a hydraulic servo mechanism or a spiral spring mechanism to achieve controllable or fixed wheel end resistance simulation.

[0083] In this embodiment, the rear axle steering unit is similar to the front axle steering unit in terms of structural arrangement, that is, the rear axle steering unit also includes a rear axle steering knuckle, which is fixedly connected to the rear axle steering wheel, and the rear axle steering trapezoidal structure 18 is connected to the rear axle resistance loading module through the rear axle steering knuckle. The rest of the parts are similar to the front axle steering unit and will not be described in detail here.

[0084] Please refer to Fig.10 , Fig.10 A flowchart of a steering test method provided by an embodiment of the present invention. An embodiment of the present invention also provides a steering test method, which is applied to the above-mentioned steering test bench and includes the following steps:

[0085] The vehicle state parameters are obtained, wherein the vehicle state parameters include the input angle and the steering wheel turning time of the steering wheel 15. It is understandable that the input angle of the steering wheel 15 can be the angle generated by the tester or the driver after manual turning, or the angle provided by the driving simulator.

[0086] Based on the input angle, determining a desired feedback angle according to a first preset calculation model;

[0087] Based on the expected feedback angle, the front axle execution motor 9 and / or the rear axle execution motor 17 are controlled to work;

[0088] The actual feedback parameters of the steering execution system are obtained; wherein the actual feedback parameters include the wheel rotation angle and the wheel rotation time.

[0089] Based on the vehicle state parameter and the actual feedback parameter, a vehicle handling stability state parameter is determined.

[0090] Specifically, the vehicle handling stability state parameters include control accuracy and real-time performance. The control accuracy is determined based on the difference between the steering wheel input angle and the wheel rotation angle; the real-time performance is determined based on the difference between the steering wheel rotation time and the wheel rotation time.

[0091] In this embodiment, the steering test method includes the following steps:

[0092] Based on the first angle sensor, acquiring the steering wheel input angle;

[0093] Based on the steering wheel input angle, determining a desired feedback torque of the steering wheel according to a second preset calculation model;

[0094] Based on the desired feedback torque, controlling the road sense execution motor to work;

[0095] Based on the first torque sensor, obtaining an actual feedback torque of the steering wheel;

[0096] Based on the expected feedback torque and the actual feedback torque, a signal closed loop of the road feel feedback system is formed to verify the accuracy of the road feel feedback system when it is in operation. It can be understood that the accuracy of the road feel feedback system when it is in operation can be reflected in the operator's subjective steering road feel, which can indicate whether the steering wheel has obtained the actual feedback torque and whether the subjective feeling corresponding to the actual feedback torque is accurate.

[0097] In this embodiment, the steering test method includes the following steps:

[0098] Based on the steering wheel input angle, determining an expected steering resistance torque according to a third preset calculation model;

[0099] Based on the expected steering resistance torque, the front axle resistance loading module and / or the rear axle resistance loading module are controlled to operate.

[0100] The steering test method further comprises the following steps: based on the tension and pressure sensor, the second angle sensor and the displacement sensor, respectively obtaining the tension and pressure of the front axle steering trapezoidal structure and / or the rear axle steering trapezoidal structure, the output angle of the front axle actuator motor and / or the rear axle actuator motor, and the lead screw displacement of the front axle steering gear and / or the rear axle steering gear;

[0101] Based on the expected steering resistance torque, the pulling force, the output angle and the lead screw displacement, a signal closed loop of the steering execution system is formed to verify the stability of the steering execution system when it is in a working state. Specifically, the stability of the steering execution system when it is in a working state refers to whether each component of the steering execution system is in a normal working state when it is in a working state, and the closed loop system formed by the closed loop can avoid deviations in the entire test system.

[0102] It is worth noting that the first preset calculation model, the second preset calculation model and the third preset calculation model are all vehicle dynamics models, and the difference between them is that they output different parameters.

[0103] Please refer to Figure 7 , Figure 7 The principle system block diagram of the steering test bench provided by the embodiment of the present invention. When the front axle steering unit and the rear axle steering unit are working, the vehicle dynamics model / wire-controlled four-wheel steering control algorithm model on the computer calculates the expected feedback angle of the front axle actuator motor 9 and / or the rear axle actuator motor 17 according to the current vehicle state parameters, and sends it to the motor controller through the CAN bus device to control the front and rear wheel angles; the expected steering resistance torque calculated according to the current vehicle dynamics model is sent to the CAN-to-analog device through the CAN bus to be converted into a voltage signal to control the output resistance torque of the magnetic powder brake 2; at the same time, the motor angle position signal, the steering gear screw displacement signal, and the steering tie rod tension pressure signal are collected through the CAN bus device and input into the algorithm model to form a signal transmission closed loop of the bench system.

[0104] When the road feel feedback system is working, the input angle of the steering wheel 15 is collected through the CAN bus device and sent to the control algorithm model. The expected feedback torque of the road feel actuator motor 11 is calculated according to the current vehicle state parameters and sent to the road sense motor controller to control the output torque. At the same time, the actual feedback torque output by the first torque sensor 14 on the steering wheel 15 column is collected and sent to the control algorithm model, forming a signal transmission closed loop of the road feel control system.

[0105] Please refer to Figure 8 , Figure 8This is a test logic block diagram of the steering test bench provided by an embodiment of the present invention. As can be seen from the figure:

[0106] 1. In the road sense feedback system, the driver inputs a 15° steering wheel angle, the controller outputs the expected feedback torque, and the road sense feedback system outputs the driver's actual feedback torque to verify the driver's subjective feeling of steering road sense;

[0107] 2. In the angle execution system, the controller outputs the front and rear axle control angles, and the angle execution system outputs the actual front and rear axle angles, and obtains the angle difference and the time difference, wherein the angle difference represents the difference between the rotation angle when the steering wheel 15 is turned and the rotation angle when the wheel is turned, and the time difference represents the difference between the time when the steering wheel 15 is turned and the time when the wheel is turned. Based on the angle difference and the time difference, the control accuracy and real-time performance of the front axle steering unit and / or the rear axle steering unit can be verified;

[0108] 3. A vehicle dynamics simulation model is established by a computer, driver control information is input, steering resistance torque is output to the magnetic powder brake 2 controller of the resistance loading module, and real-time state parameters of the simulated vehicle are output to the wire-controlled four-wheel steering controller. The controller outputs the desired steering angles of the front and rear wheels to the front and rear axle angle execution systems according to the wire-controlled four-wheel steering control algorithm, and outputs the actual steering angles of the front and rear wheels to the vehicle dynamics simulation model of the computer under the action of the angle execution motor and the magnetic powder brake 2. The vehicle dynamics simulation model of the computer completes the online simulation calculation work according to the steering wheel 15 steering angle information obtained by the sensor and the actual steering angles of the front and rear wheels (i.e., the actual output steering angles of the front axle execution motor 9 and the rear axle execution motor 17), outputs the vehicle handling stability state parameters, and verifies the function of the wire-controlled four-wheel steering control algorithm by comparing with the theoretical simulation results of conventional vehicles.

[0109] Please refer to Fig. 9 , Fig. 9The logic block diagram of the joint simulation of the steering test bench and the driving simulator provided in the embodiment of the present invention. The driving simulator is used to provide driver operation signals such as steering, braking and acceleration, and at the same time, receive the actual feedback torque of the steering wheel 15, and display the vehicle status on the display screen to inform the driver of the current vehicle status; the NI real-time machine sends the driving simulator signal to the controller end through the CAN bus; the controller end runs the wire control steering algorithm, calculates the current expected turning angle and sends it to the steering front axle execution motor 9 driver and / or the rear axle execution motor 17 driver through the CAN bus, so that the motor drives the wheel to the expected turning angle, and feeds back the actual turning angle to the controller end through the sensor, which is used for the self-checking and steering control strategy module in the control algorithm; the controller end feeds back the actual execution parameters of the bench to the CarSim vehicle model in the NI real-time machine, and routes the model parameters to the PC-side Carla software through the central gateway module of the NI real-time machine, and the PC-side Carla software feeds back the vehicle status and the real-time environment of the vehicle movement to the display screen.

[0110] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this specification. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this specification.

[0111] Finally, it should be understood that the embodiments in this specification are only used to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, as an example and not a limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly introduced and described in this specification.

Claims

1. A steering test bench, characterized in that: include: A steering execution system, including a front axle steering unit and a rear axle steering unit; The data processing system comprises a data acquisition module and a data processing module, wherein the data acquisition module is used to obtain vehicle state parameters and actual feedback parameters of the steering execution system; the data processing module is used to determine the expected feedback angle based on the vehicle state parameters and a first preset calculation model; and is also used to determine the vehicle handling stability state parameters based on the vehicle state parameters and the actual feedback parameters; Wherein, the steering execution system performs work according to the expected feedback angle, and in a first state, the front axle steering unit, the rear axle steering unit and the data processing system are coupled to form a four-wheel steering test system; in a second state, the front axle steering unit and the data processing system are coupled to form a front axle steering test system; In a third state, the rear axle steering unit is coupled to the data processing system to form a rear axle steering test system.

2. The steering test bench according to claim 1, characterized in that: The steering test bench also includes a road feel feedback system, which includes a road feel actuator motor, a steering wheel and a controller. The road feel actuator motor is connected to the steering wheel, and the controller is configured to control the road feel actuator motor to output feedback torque to the steering wheel.

3. The steering test bench according to claim 2, characterized in that: The vehicle state parameter at least includes an input angle of a steering wheel, and the data acquisition module includes a first angle sensor and a first torque sensor; the first angle sensor is installed in the road sense feedback system and is configured to detect the input angle of the steering wheel; The first torque sensor is installed on the road feel feedback system and is configured to detect an actual feedback torque of the steering wheel.

4. The steering test bench according to claim 3, characterized in that: The steering wheel comprises a wheel body and a column. The first rotation angle sensor and the first torque sensor are both mounted on the column and are coaxially arranged with the column.

5. The steering test bench according to claim 2, characterized in that: The road sense feedback system also includes a first reducer, and the road sense actuator motor is connected to the steering wheel via the first reducer.

6. The steering test bench according to claim 1, characterized in that: The front axle steering unit includes a front axle actuator motor, a front axle steering trapezoidal structure and a front axle steering wheel, wherein the front axle actuator motor is connected to the front axle steering trapezoidal structure, and the front axle steering trapezoidal structure is connected to the front axle steering wheel; the rear axle steering unit includes a rear axle actuator motor, a rear axle steering trapezoidal structure and a rear axle steering wheel, wherein the rear axle actuator motor is connected to the rear axle steering trapezoidal structure, and the rear axle steering trapezoidal structure is connected to the rear axle steering wheel.

7. The steering test bench according to claim 6, characterized in that: The data acquisition module also includes a pulling and pressure sensor and a second rotation angle sensor. The pulling and pressure sensor is installed on the front axle steering unit and / or the rear axle steering unit, and is configured to detect the pulling and pressure of the front axle steering trapezoidal structure and / or the rear axle steering trapezoidal structure; the second rotation angle sensor is installed on the front axle steering unit and / or the rear axle steering unit, and is configured to detect the output angle of the front axle actuator motor and / or the rear axle actuator motor.

8. The steering test bench according to claim 6, characterized in that: The front axle steering trapezoidal structure includes a front axle steering gear, a front axle universal joint and a front axle steering rod, and the front axle steering gear is connected to the front axle steering rods on both sides through the front axle steering knuckle; the rear axle steering trapezoidal structure includes a rear axle steering gear, a rear axle universal joint and a rear axle steering rod, and the rear axle steering gear is connected to the rear axle steering rods on both sides through the rear axle steering knuckle.

9. The steering test bench according to claim 8, characterized in that: The data acquisition module also includes a displacement sensor installed on the front axle steering gear and / or the rear axle steering gear, and the displacement sensor is configured to detect the screw displacement of the front axle steering gear and / or the rear axle steering gear.

10. The steering test bench according to claim 6, characterized in that: The front axle steering unit also includes a front axle resistance loading module, the front axle steering trapezoidal structure is connected to the front axle resistance loading module, and the front axle resistance loading module is configured to provide wheel-end resistance when the front axle steering wheel rotates; and / or, the rear axle steering unit also includes a rear axle resistance loading module, the rear axle steering trapezoidal structure is connected to the rear axle resistance loading module, and the rear axle resistance loading module is configured to provide wheel-end resistance when the rear axle steering wheel rotates.

11. The steering test bench according to claim 10, characterized in that: The front axle steering unit also includes a front axle steering knuckle, which is fixedly connected to the front axle steering wheel, and the front axle steering trapezoidal structure is connected to the front axle resistance loading module through the front axle steering knuckle; and / or, the rear axle steering unit also includes a rear axle steering knuckle, which is fixedly connected to the rear axle steering wheel, and the rear axle steering trapezoidal structure is connected to the rear axle resistance loading module through the rear axle steering knuckle.

12. The steering test bench according to claim 11, characterized in that: The front axle resistance loading module has the same structure as the rear axle resistance loading module, and both include a magnetic powder brake and a second reducer, the magnetic powder brake is connected to the second reducer, and the output shaft of the second reducer is connected to the front axle steering trapezoidal structure through the front axle steering knuckle; and / or, the output shaft of the second reducer is connected to the rear axle steering trapezoidal structure through the rear axle steering knuckle.

13. The steering test bench according to claim 1, characterized in that: The steering test bench also includes a support frame, and the front axle steering unit and the rear axle steering unit are both installed on the support frame.

14. A steering test method, applied to the steering test bench according to any one of claims 1 to 13, characterized in that: The steps include: Get vehicle status parameters; Based on the vehicle state parameter and according to a first preset calculation model, determining a desired feedback angle; Based on the expected feedback angle, control the front axle steering unit and / or the rear axle steering unit to operate; Obtain actual feedback parameters of the steering execution system; Based on the vehicle state parameter and the actual feedback parameter, a vehicle handling stability state parameter is determined.

15. The turning test method according to claim 14, characterized in that: The vehicle state parameters include the steering wheel input angle and the steering wheel rotation time, the actual feedback parameters include the wheel rotation angle and the wheel rotation time, and the vehicle handling stability state parameters include control accuracy and real-time performance.

16. The turning test method according to claim 15, characterized in that: The determining of the vehicle handling stability state parameter based on the vehicle state parameter and the actual feedback parameter includes: Determining the control accuracy based on the difference between the steering wheel input angle and the wheel rotation angle; The real-time performance is determined based on the difference between the steering wheel rotation time and the wheel rotation time.

17. The turning test method according to claim 15, characterized in that: The following steps are also included: Based on the first angle sensor, acquiring the steering wheel input angle; Based on the steering wheel input angle, determining a desired feedback torque of the steering wheel according to a second preset calculation model; Based on the desired feedback torque, controlling the road sense execution motor to work; Based on the first torque sensor, obtaining an actual feedback torque of the steering wheel; Based on the expected feedback torque and the actual feedback torque, a signal closed loop of the road feel feedback system is formed to verify the accuracy of the road feel feedback system when it is in a working state.

18. The turning test method according to claim 16, characterized in that: The following steps are also included: Based on the steering wheel input angle, determining an expected steering resistance torque according to a third preset calculation model; Based on the expected steering resistance torque, the front axle resistance loading module and / or the rear axle resistance loading module are controlled to operate.

19. The turning test method according to claim 18, characterized in that: The following steps are also included: Based on the pulling and pressure sensor, the second angle sensor and the displacement sensor, respectively obtaining the pulling and pressure of the front axle steering trapezoidal structure and / or the rear axle steering trapezoidal structure, the output angle of the front axle actuator motor and / or the rear axle actuator motor, and the screw displacement of the front axle steering gear and / or the rear axle steering gear; Based on the expected steering resistance torque, the pulling force, the output angle and the lead screw displacement, a signal closed loop of the steering execution system is formed to verify the stability of the steering execution system when it is in a working state.

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