Chassis dynamometer, vehicle test bench, and method for simulating real-world vehicle driving

Abstract

The present application discloses a chassis dynamometer for testing vehicles. The chassis dynamometer includes a front wheel test assembly, a rear wheel test assembly, and a control device. The front wheel test assembly includes a front base frame, two universal slides slidably disposed on the front base frame along a second direction perpendicular to the first direction and the vertical direction and configured to rotate about the vertical direction, a front wheel hub bracket rotatably disposed on the universal slides, and a turning force assist drive device fixed to the front wheel hub bracket and configured to drive the front wheel hub bracket to rotate about the vertical direction. The present application also discloses a vehicle test bench including the chassis dynamometer and a method for simulating actual vehicle driving.

Description

[Technical Field]

[0001] The present application relates to a vehicle testing device, in particular a chassis dynamometer, a vehicle test bench including the chassis dynamometer, and a method for simulating real road driving of a vehicle. [Background technology]

[0002] The development cycles of advanced driver assistance systems (ADAS), active safety systems, and autonomous driving (AD) technologies require extensive calibration, testing, and validation before these systems are deployed on production lines and in real-world applications. OEMs and automotive suppliers benefit from accelerating these development cycles and extending active testing time to ensure conformance to expected performance levels and test fault tolerance limits. Traditional approaches to these testing tasks are typically completed by running prototype vehicles with driving capabilities in closed proving grounds and conducting limited performance evaluations on public roads. Therefore, the costs associated with these testing methods severely limit the number and scope of these tests. Instead, simulation-based ADAS technology development and testing is often preferred, which has the key advantage of being able to easily vary a wide range of input parameters and scenarios. While only a small subset of all possible scenarios will cause problems with ADAS functionality, they can potentially lead to malfunctions. Therefore, a subset of scenarios must be appropriately selected from all possible scenario variations to ensure sufficient scenario coverage. However, simulation-based analysis alone is often insufficient or impossible to fully validate such systems in all possible operating scenarios before the systems are deployed.

[0003] To solve this problem, engineers are developing new testing modes that combine virtual and real testing in various ways, allowing for realistic simulation of the physical models of all relevant subsystems and active safety control systems. In the automotive field, real-time hardware-in-the-loop (HIL) simulation is a fairly common research area and is used in engine development, electronic control unit (ECU) development, and the development and testing of electric vehicle components. A specific implementation of HIL simulation technology for the entire vehicle is named vehicle-in-the-loop (VIL) simulation. This concept involves placing a complete real-world vehicle on a rolling chassis dynamometer to realistically simulate the environment, sensors, and / or the vehicle itself. Actual hardware components, such as ECUs or sensors and their respective control logic, can be tested in a coupled manner in the real-time simulation environment. HIL simulation is widely used in the development of active safety systems, such as ABS and ESC systems. In these implementations, a vehicle dynamics simulation outputs relevant and necessary signals (e.g., wheel speed, acceleration, rotational speed, steering angle, etc.) to an ECU to test the response of the ECU and / or its programmed software functions. In such a setup, vehicle dynamics and road conditions are typically simulated, and a physical ECU is integrated into the simulation to evaluate the ECU's response to virtual driving scenarios. A further extension of the hybrid testing concept is the vehicle-in-the-loop (VIL) simulation concept, where a real vehicle on a test bench is combined with a simulation framework. The idea behind this setup is that the vehicle's behavior in the simulation is directly coupled to the vehicle driving on the test bench. In such a setup, the test bench needs to be able to set specific road load conditions provided by the simulation environment.When ADAS functions need to be integrated and evaluated in such a framework, conventional test benches reach their limits and are unable to simulate steering behavior, i.e., it is not possible to test vehicle steering in a VIL simulation using a conventional linear rolling vehicle test bench. Summary of the Invention [Problem to be solved by the invention]

[0004] In summary, it is desirable to develop a chassis dynamometer and a vehicle test bench including the chassis dynamometer to simulate vehicle turning scenarios and obtain corresponding experimental results. [Means for solving the problem]

[0005] To address the problems in the prior art, the present application proposes a chassis dynamometer and corresponding vehicle testing method for developing and testing ADAS, active safety systems, and AD technologies. Conventional linear rolling chassis dynamometers do not allow for physical steering of the vehicle. In contrast, the present application's chassis dynamometer allows for independent steering of the front wheels by rotating the vehicle's front wheel hub assemblies about their respective vertical axes. This allows the driver or an automated driving controller to apply longitudinal and lateral inputs to the vehicle, i.e., acceleration, braking, and steering inputs.

[0006] The present application also proposes a vehicle test bench, including a chassis dynamometer, for performing dynamic and visual simulations of driving scenarios for manually or autonomously driven vehicles and for carrying out real rolling condition tests on the vehicle test bench, and a corresponding vehicle testing method. Using this method, various driving conditions can be simulated and reproduced, allowing corresponding ADAS, active safety systems, and AD technologies to be adjusted to meet expected performance targets.

[0007] The present application proposes a chassis dynamometer for testing vehicles. The chassis dynamometer includes a front wheel test assembly, a rear wheel test assembly, and a control device. The rear wheel test assembly is spaced from the front wheel test assembly by a distance in a first direction and is configured to adjust the distance between the front and rear wheel test assemblies to accommodate different vehicle wheelbases. The control device is electrically connected to the front and rear wheel test assemblies and is configured to adjust the positions and rotational speeds of the front and rear wheel test assemblies and synchronize the rotational speeds of the front and rear wheel test assemblies. The chassis dynamometer is characterized in that the front wheel test assembly comprises a front base frame fixed to the ground, two universal slides slidably arranged on the front base frame along a second direction perpendicular to the first direction and the vertical direction and configured to rotate around the vertical direction, a front wheel hub bracket rotatably arranged on the universal slide, and a turning force assist drive device fixed to the front wheel hub bracket and configured to drive the front wheel hub bracket to rotate around the vertical direction and cooperate with the steering of the vehicle's front wheels.

[0008] According to an optional embodiment, the front wheel testing assembly also includes a front wheel hub rotatably disposed on the front wheel hub bracket, the rotation axis of which is parallel to the ground and which cooperates with the rolling of the front wheel of the vehicle, and a front wheel hub motor disposed on the front wheel hub bracket and connected to the front wheel hub by a front wheel hub transmission for driving the front wheel hub.

[0009] According to an optional embodiment, the distance between the two universal slides corresponds to the front tread of the vehicle.

[0010] According to an optional embodiment, the rear wheel testing assembly includes a rear base frame fixed to the ground, a rear slide slidably arranged on the rear base frame along a first direction, a rear wheel hub bracket arranged on the rear slide, a rear slide drive device fixed to the rear wheel hub bracket for driving the rear slide to translate along the first direction and adjusting the position of the rear slide on the rear base frame to fit the wheelbase of the vehicle, a rear wheel hub rotatably arranged on the rear wheel hub bracket, the rotation axis of which is parallel to the ground and cooperates with the rolling of the rear wheel of the vehicle, and a rear wheel hub motor arranged on the rear wheel hub bracket and connected to the rear wheel hub by a rear wheel hub transmission for driving the rear wheel hub.

[0011] According to an optional embodiment, two front wheel hubs are arranged on each of the front wheel hub brackets, and a front wheel hub transmission is configured to connect the two front wheel hubs to a front wheel hub motor and enable the two front wheel hubs to rotate synchronously, and two rear wheel hubs are arranged on each of the rear wheel hub brackets, and a rear wheel hub transmission is configured to connect the two rear wheel hubs to a rear wheel hub motor and enable the two rear wheel hubs to rotate synchronously.

[0012] According to an optional embodiment, two front wheel hubs are arranged on each of the front wheel hub brackets, and a front wheel hub transmission is configured to connect the two front wheel hubs to a front wheel hub motor and enable the two front wheel hubs to rotate synchronously, and one rear wheel hub is arranged on each of the rear wheel hub brackets, and a rear wheel hub transmission is configured to connect the rear wheel hub to the rear wheel hub motor.

[0013] According to an optional embodiment, one front wheel hub is disposed on each of the front wheel hub brackets, and the front wheel hub transmission is configured to connect the front wheel hubs to the front wheel hub motors, and one rear wheel hub is disposed on each of the rear wheel hub brackets, and the rear wheel hub transmission is configured to connect the rear wheel hubs to the rear wheel hub motors.

[0014] According to optional embodiments, rotation of the front wheel test assembly about the vertical direction is achieved by a passive method, an active method, or a hybrid method. In the passive method, the vehicle's steering system provides steering power to drive the vehicle's front wheels to steer, and the vehicle's front wheels then drive the front wheel hubs in rolling contact with the front wheels to steer. In the active method, the steering power is provided by a turning force assist drive of the front wheel test assembly, driving the front wheel hub bracket and the front wheel hub disposed thereon to rotate about the vertical direction, and then driving the vehicle's front wheels in rolling contact with the front wheel hub and the steering mechanism to steer synchronously. In the hybrid method, the control device receives a steering command signal from the vehicle's steering control system and controls the turning force assist drive to follow the steering command signal and provide auxiliary power to drive the front wheel hub bracket and the front wheel hub disposed thereon to steer synchronously with the vehicle's front wheels.

[0015] The present application also proposes a vehicle test bench, which includes a chassis dynamometer according to the present application, which is arranged in a pit of a room in which the vehicle test bench is arranged and is substantially flush with the indoor ground, a display device arranged around the chassis dynamometer and configured to display images simulating road environments and scenes of vehicle travel, an airflow simulation device arranged near the chassis dynamometer and configured to generate airflow simulating ambient wind, and a temperature control device arranged indoors away from the chassis dynamometer and used to control the indoor temperature to simulate the ambient temperature.

[0016] The present application also proposes a method for simulating actual road driving of a vehicle. The method includes the following steps: Step S101: Park a vehicle on the chassis dynamometer of the present application. Step S102: Adjust the positions of the front and rear wheel test assemblies using a control device of the chassis dynamometer so that the front and rear wheels of the vehicle contact the front and rear wheel hubs, respectively. If two front wheel hubs are provided on each front wheel hub bracket, the front wheels of the vehicle are fitted between the two front wheel hubs, and the rear wheels of the vehicle contact the rear wheel hub. If one front wheel hub 1004 is provided on each front wheel hub bracket, the front wheels of the vehicle contact the front wheel hub, and the rear wheels of the vehicle contact the rear wheel hub. Step S103: Fix the vehicle on the chassis dynamometer using a fixing device to prevent the vehicle from moving relative to the chassis dynamometer during testing. Step S104: Start the vehicle under test using a driver or an automated driving controller, and perform operations such as acceleration, deceleration, and steering to simulate road driving.

[0017] According to an optional embodiment, in step S104, if the vehicle is a front-wheel drive vehicle, the movement of the vehicle's front wheels is transmitted to the front hub transmission through the front hub, and then to the front hub motor, and the speed of the rear hub motor is set according to the speed of the front hub motor through the control device, driving the rear wheels to rotate through the rear hub transmission and the rear hub. If the vehicle under test is a rear-wheel drive vehicle, the movement of the vehicle's rear wheels is transmitted to the rear hub transmission through the rear hub, and then to the rear hub motor, and the speed of the front hub motor is set according to the speed of the rear hub motor through the control device, driving the front wheels to rotate through the front hub transmission and the front hub.

[0018] The chassis dynamometer and vehicle test bench according to the present invention can simulate the maximum speed of the vehicle under test and any steering angle within the maximum steering angle range, and can achieve synchronization between the front and rear wheels of the vehicle under test. The chassis dynamometer and vehicle test bench according to the present invention can solve the technical problems of the prior art, such as the high risk and environmental constraints of public road testing, and can simulate the steering of a vehicle while it is in motion and the synchronization between the front and rear wheels, thereby replacing some of the functions of public road testing, saving many human and material resources, saving enormous costs, and having the advantages of simple structure, easy operation, safety, and efficiency.

[0019] The above and other aspects of the present application will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which: For clarity of illustration, the drawings may be drawn to different scales, but it should be noted that this does not affect the understanding of the present application. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a side view of a vehicle test bench according to the present application; [Figure 2] FIG. 2 is a top view of the vehicle test bench of FIG. 1. [Figure 3] FIG. 2 is a perspective view of a front wheel test assembly of a chassis dynamometer of the vehicle test bench of FIG. 1. [Figure 4] FIG. 4 is a perspective view of the nose wheel test assembly of FIG. 3, with the nose wheel test assembly in a steering position. [Figure 5] FIG. 10 is a side view of another embodiment of a nose wheel test assembly. [Figure 6] 1 is a flowchart of a method for simulating steering and synchronizing front and rear wheels while the vehicle is moving. DETAILED DESCRIPTION OF THE INVENTION

[0021] Exemplary embodiments of the present application are described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present application are illustrated in the accompanying drawings, it should be understood that the present application can be embodied in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to facilitate a more complete understanding of the present application and to fully convey the scope of the present application to those skilled in the art. It should be noted that when an element is referred to as being "fixed" or "mounted" to another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being "connected" to another element, it may be directly connected to the other element or indirectly connected to the other element. It should be understood that the orientations or positional relationships indicated by terms such as "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," and "outside" are based on the orientations or positional relationships shown in the accompanying drawings, and are for convenience only to explain and simplify the present application, and do not indicate or imply that the referenced devices or elements must have a particular orientation or be constructed and operated in a particular orientation, and therefore cannot be understood as limitations on the present application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or the number of technical features shown. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "plurality" and "several" mean two or more unless clearly and specifically defined otherwise.

[0022] FIG. 1 shows a side view of a vehicle test bench according to the present application. FIG. 2 shows a top view of the vehicle test bench of FIG. 1. The vehicle test bench according to the present application is a rolling test bench that can hold a vehicle in the center of the vehicle test bench fully automatically. During testing, the vehicle on the vehicle test bench can be controlled by a driver in the vehicle, by an autonomous driving controller in the vehicle, or jointly by the autonomous driving controller and an auxiliary controller of the vehicle test bench. In addition to rolling tests, braking tests, and ABS tests, the vehicle test bench according to the present application can also perform dynamic function tests of autonomous vehicles, such as tests involving steering operations and tests of autonomous driving behavior under typical traffic conditions.

[0023] As shown in FIG. 1, the vehicle test bench 1 includes a chassis dynamometer 10, a display device 20, an airflow simulation device 30, and a temperature control device 40. The vehicle test bench 1 is located in a relatively closed room. The chassis dynamometer 10 is located within a pit in the room and is substantially flush with the indoor floor. The display device 20 is located around the chassis dynamometer 10 and is used to display images that simulate the environment. The airflow simulation device 30 is located near the chassis dynamometer 10 and is used to generate airflow that simulates ambient wind. The temperature control device 40 is located indoors, away from the chassis dynamometer 10, and is used to control the indoor temperature to simulate the ambient temperature.

[0024] For the convenience of the following explanation, we will now define a first coordinate system for the vehicle test bench 1. In the first coordinate system, the X-axis direction is the direction in which the vehicle travels in a straight line within the vehicle test bench 1. The Z-axis direction is the vertical direction, and the Y-axis direction is the horizontal direction perpendicular to the X-axis and Z-axis.

[0025] The chassis dynamometer 10 includes a front wheel test assembly 100, a rear wheel test assembly 101, a fixing device 102, and a control device 103. The rear wheel test assembly 101 is spaced apart from the front wheel test assembly 100 by a distance along the X-axis direction, and the distance between the rear wheel test assembly 101 and the front wheel test assembly 100 can be adjusted to accommodate different vehicle wheelbases. The fixing device 102 is disposed near the front wheel test assembly 100 and the rear wheel test assembly 101 and is connected to the body and wheels of the vehicle under test, and is used to fix the vehicle under test on the chassis dynamometer 10. The control device 103 is electrically connected to the front wheel test assembly 100 and the rear wheel test assembly 101, and can adjust the position and rotational speed of the front wheel test assembly 100 and the rear wheel test assembly 101, and synchronize the rotational speeds of multiple front wheel test assemblies 100 and multiple rear wheel test assemblies 101.

[0026] The rear wheel test assembly 101 includes a rear chassis 1010, a rear slide 1011, a rear wheel hub bracket 1012, a rear slide drive device 1013, a rear wheel hub 1014 (not shown in FIG. 1 , see FIG. 2), a rear wheel hub motor 1015, and a rear wheel hub transmission device. The rear chassis 1010 is fixed to the bottom of an indoor pit. The rear slide 1011 is slidably disposed on the rear chassis 1010 along the X-axis direction. The rear wheel hub bracket 1012 is disposed on the rear slide 1011. The rear slide drive device 1013 is fixed to the rear wheel hub bracket 1012 and drives the rear slide 1011 to translate along the X-axis, thereby adjusting the position of the rear slide 1011 on the rear chassis 1010 to fit the wheelbase of the vehicle under test. The rear wheel hub 1014 is rotatably disposed on the rear wheel hub bracket 1012, and its rotation axis is parallel to the ground so as to cooperate with the rolling of the rear wheel of the vehicle under test. That is, the rear wheel hub 1014 can roll on the rear wheel hub bracket 1012. The rear wheel hub motor 1015 is disposed on the rear wheel hub bracket 1012 and is connected to the rear wheel hub 1014 by a rear wheel hub transmission to drive the rear wheel hub 1014.

[0027] 1, only one rear wheel hub 1014 is disposed on the rear wheel hub bracket 1012, but the present application can be understood to include a case where two rear wheel hubs 1014 are disposed on the rear wheel hub bracket 1012. In this case, the rear wheel hub transmission is configured to connect the two rear wheel hubs 1014 to a rear wheel hub motor 1015 and rotate the two rear wheel hubs 1014 synchronously.

[0028] FIG. 3 shows a side view of the front wheel test assembly of the chassis dynamometer of the vehicle test bench of FIG. 1. The front wheel test assembly 100 includes a front base frame 1000, two universal slides 1001 (one of which is shown in the figure), a front wheel hub bracket 1002, a turning force assist drive 1003, a front wheel hub 1004, a front wheel hub motor 1005, and a front wheel hub transmission 1006. The front base frame 1000 is fixed to the bottom of the indoor pit. The universal slide 1001 is slidably disposed on the front base frame 1000 along the Y-axis direction and can rotate around the Z-axis. The distance between the two universal slides 1001 depends on the front tread of the vehicle under test. The front wheel hub bracket 1002 is rotatably disposed on the universal slide 1001. The turning force assist drive unit 1003 is fixed on the front wheel hub bracket 1002 and is used to drive the front wheel hub bracket 1002 to rotate about the Z-axis direction. The turning force assist drive unit 1003 may be a motor with a fixed small gear, which drives a large gear fixed on the front wheel hub bracket 1002 to rotate through gear transmission, thereby driving the front wheel hub bracket 1002 to rotate. The front wheel hub 1004 is rotatably disposed on the front wheel hub bracket 1002, and its rotation axis is parallel to the ground so as to cooperate with the rotation of the front wheel of the vehicle under test. In other words, the front wheel hub 1004 can roll on the front wheel hub bracket 1002. The front wheel hub motor 1005 is disposed on the front wheel hub bracket 1002 and connected to the front wheel hub 1004 by a front wheel hub transmission 1006 and is used to drive the front wheel hub 1004.

[0029] 2 and 3, in this embodiment, two front wheel hubs 1004 are disposed on each front wheel hub bracket 1002. A front wheel hub transmission 1006 connects the two front wheel hubs 1004 to a front wheel hub motor 1005, causing the two front wheel hubs 1004 to rotate synchronously. The technical effect of disposing two front wheel hubs 1004 on each front wheel hub bracket 1002 is that the front wheel of the vehicle under test can be positioned between the two front wheel hubs 1004 on each front wheel hub bracket 1002, providing greater stability during rotation. The front wheel testing assembly 100 also includes a safety blocking roller 1007 disposed between the two front wheel hubs 1004 to prevent the front wheel of the vehicle under test from slipping out from between the two front wheel hubs 1004.

[0030] It should be noted that if one rear wheel hub 1014 is provided on the rear wheel hub bracket 1012, one or two front wheel hubs 1004 may be provided on each front wheel hub bracket 1002. If two rear wheel hubs 1014 are provided on the rear wheel hub bracket 1012, only two front wheel hubs 1004 may be provided on each front wheel hub bracket 1002.

[0031] FIG. 4 shows a three-dimensional view of the front wheel test assembly of FIG. 3 , with the front wheel test assembly in a steering position. The front wheel test assembly 100 can be rotated from the default (straight ahead) position to the steering position in three ways. In the first way, the steering system of the vehicle under test drives the front wheels of the vehicle under test to steer, and then the front wheels drive the front wheel hub 1004, which is in rolling contact with the front wheels, to steer. In this case, the steering system of the vehicle under test provides the steering force. In the second way, the turning force assist drive 1003 of the front wheel test assembly 100 provides the steering force and drives the front wheel hub bracket 1002 and the front wheel hub 1004 disposed thereon to rotate about the Z-axis, and then drives the front wheel and steering mechanism, which are in rolling contact with the front wheel hub 1004, to steer synchronously. In the third method, the steering control system of the vehicle under test outputs a steering command signal to the control device 103, and then the control device 103 controls the turning force assist drive device 1003 of the front wheel test assembly 100 to follow the steering command signal to provide auxiliary power, thereby realizing synchronous steering of the front wheel hub bracket 1002, the front wheel hub 1004 arranged thereon, and the front wheel.

[0032] FIG. 5 shows a side view of another embodiment of a front wheel test assembly. Compared to the embodiment of FIG. 2, the embodiment of FIG. 5 has one front wheel hub 1004 provided on each front wheel hub bracket 1002. A front wheel hub transmission 1006 connects the front wheel hub 1004 to a front wheel hub motor 1005. The technical effect of having one front wheel hub 1004 on each front wheel hub bracket 1002 is that a complex front wheel hub transmission 1006 is not required to synchronize the rotational speeds of different front wheel hubs 1004 on the same front wheel hub bracket 1002, thereby simplifying the overall structure of the front wheel test assembly 100. In this embodiment, the front wheel test assembly 100 does not include a safety blocking roller 1007.

[0033] 6 shows a flow chart of a method for simulating steering and synchronizing front and rear wheels while a vehicle is in motion, which includes the following steps:

[0034] Step S101: The vehicle to be tested is stopped on the chassis dynamometer 10.

[0035] Step S102: The positions of the front wheel test assembly 100 and the rear wheel test assembly 101 are adjusted by the control device 103 of the chassis dynamometer 10 so that the front and rear wheels of the vehicle under test come into contact with the front wheel hub 1004 and the rear wheel hub 1014, respectively.

[0036] When two front wheel hubs 1004 are placed on each front wheel hub bracket 1002, the front wheel of the vehicle under test is fitted between the two front wheel hubs 1004 and the rear wheel of the vehicle under test is in contact with the rear wheel hub 1014 in step S102.

[0037] When one front wheel hub 1004 is placed on each front wheel hub bracket 1002, the front wheels of the vehicle under test contact the front wheel hubs 1004 and the rear wheels of the vehicle under test contact the rear wheel hubs 1014 in step S102.

[0038] Step S103: The vehicle under test is fixed onto the chassis dynamometer 10 by the fixing device 102 so that the vehicle under test does not move relative to the chassis dynamometer 10 during the test.

[0039] Step S104: The driver or the automatic driving controller starts the vehicle under test, and performs operations such as acceleration, deceleration, and steering to simulate road driving.

[0040] Due to the presence of a steering trapezoid, the wheels slide along the Y-axis direction (i.e., transverse to the vehicle's direction of travel) when turning, and this sliding can be compensated for by the sliding of the universal slide 1001 along the Y-axis direction. If the vehicle under test is front-wheel drive, the movement of the front wheels of the vehicle under test is transmitted via the front wheel hub 1004 to the front hub transmission 1006 and then to the front hub motor 1005. The control device 103 sets the speed of the rear hub motor 1015 according to the speed of the front hub motor 1005, thereby driving the rear wheels to rotate via the rear hub transmission and rear hub 1014. If the vehicle under test is rear-wheel drive, the above-described power transmission process is reversed. That is, the movement of the rear wheels of the vehicle under test is transmitted via the rear wheel hub 1014 to the rear hub transmission and then to the rear hub motor 1015. The control device 103 sets the rotation speed of the front wheel hub motor 1005 according to the rotation speed of the rear wheel hub motor 1015, thereby driving the front wheel to rotate via the front wheel hub transmission 1006 and the front wheel hub 1004. In this way, steering operation of the vehicle under test while traveling on a simulated road and synchronization of the rotation speeds of the front and rear wheels can be achieved.

[0041] In one embodiment, the fixing device 102 includes a tension stake 1020 and a flexible chain 1021. The tension stake 1020 is fixed to the ground. The flexible chain 1021 is connected between the tension stake 1020 and the front or rear wheel of the vehicle under test to make the testing process more stable.

[0042] The maximum speed of the vehicle under test in a steering state on the vehicle test bench 1 is usually set lower than the maximum speed in a non-steering (i.e., straight-ahead) state to improve the safety of the test. The maximum speed and torque of the vehicle under test can be adjusted according to the specifications of the front wheel hub motor 1005 and the rear wheel hub motor 1015. During the test, the tester (or the automatic driving control device) turns the steering wheel of the vehicle under test within the range of the maximum speed and maximum steering angle.

[0043] The vehicle test bench 1 according to the present invention can simulate any steering angle within the maximum speed and maximum steering angle range of the vehicle under test, and can achieve synchronization between the front and rear wheels of the vehicle under test. The vehicle test bench 1 according to the present invention can solve the technical problems of the prior art, such as the high risk and environmental constraints of public road testing, and can achieve the function of simulating steering and synchronization between the front and rear wheels while the vehicle is moving, thereby replacing some of the public road testing functions, saving many human and material resources, saving enormous costs, and having the advantages of simple structure, easy operation, safety, and high efficiency.

[0044] The control device 103 includes a non-volatile memory, a data processing unit, and a read-write memory. The non-volatile memory has a memory element in which a computer program P is stored. When the computer program is executed, the data processing unit performs the method according to the present application for simulating steering and synchronizing the front and rear wheels while the vehicle is moving. The control device 103 further includes a bus controller, a serial communication port, I / O components, an A / D converter, a time and date input transmission unit, an event counter, an interrupt controller, etc. (not shown).

[0045] When a data processing unit is described as performing a particular function, this means that the data processing unit affects a particular part of a program stored in non-volatile memory or a particular part of a program stored in read-write memory.

[0046] Those skilled in the art will appreciate that in addition to implementing a method for simulating steering and synchronizing front and rear wheels while a vehicle is in motion purely in computer-readable program code, the steps of the method can also be logically programmed to enable the controller 103 to implement the same functionality in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Thus, the controller 103 can be considered a hardware component, and the devices for implementing the various functions contained therein can also be considered structures within the hardware component. Alternatively, the devices for implementing the various functions can be considered both software modules for implementing the method and structures within the hardware component.

[0047] The above description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the embodiments to the variations described. Many modifications and variations will be apparent to those skilled in the art. These embodiments have been chosen and described to best illustrate principles and practical applications, allowing those skilled in the art to understand the embodiments in various embodiments and in various modifications suitable for the intended use. Within the framework of the embodiments, the above-described components and features can be combined among different embodiments.

Claims

1. A chassis dynamometer (10) for testing a vehicle, comprising: a nose wheel test assembly (100); a rear wheel test assembly (101) spaced apart from the front wheel test assembly (100) by a distance along a first direction, the rear wheel test assembly (101) being configured to allow the distance between the rear wheel test assembly (101) and the front wheel test assembly (100) to be adjusted to accommodate different vehicle wheelbases; a control device (103) electrically connected to the front wheel test assembly (100) and the rear wheel test assembly (101) and configured to adjust the positions and rotational speeds of the front wheel test assembly (100) and the rear wheel test assembly (101) and synchronize the rotational speeds of the front wheel test assembly (100) and the rear wheel test assembly (101); Equipped with The front wheel test assembly (100) a front base frame (1000) fixed to the ground; Two universal slides (1001) slidably disposed on the front base frame (1000) along a second direction perpendicular to the first direction and the vertical direction, and configured to be rotatable around the vertical direction; a front wheel hub bracket (1002) rotatably disposed on the universal slide (1001); a turning force assist drive device (1003) fixed to the front wheel hub bracket (1002) and configured to drive the front wheel hub bracket (1002) to rotate about a vertical direction to cooperate with steering of the front wheels of the vehicle; A chassis dynamometer comprising:

2. 2. A chassis dynamometer (10) according to claim 1, The front wheel test assembly (100) a front wheel hub (1004) rotatably disposed on the front wheel hub bracket (1002) and having an axis of rotation parallel to the ground for rolling cooperation with the front wheel of the vehicle; a front wheel hub motor (1005) disposed on the front wheel hub bracket (1002) and connected to the front wheel hub (1004) by a front wheel hub transmission (1006) for driving the front wheel hub (1004); A chassis dynamometer further comprising:

3. 3. A chassis dynamometer (10) according to claim 2, characterized in that the distance between the two universal slides (1001) corresponds to the front tread of the vehicle.

4. A chassis dynamometer (10) according to any one of claims 1 to 3, The rear wheel testing assembly (101) a rear chassis (1010) fixed to the ground; a rear slide (1011) slidably disposed on the rear chassis (1010) along a first direction; a rear wheel hub bracket (1012) disposed on the rear slide (1011); a rear slide drive device (1013) fixed to the rear wheel hub bracket (1012) for driving the rear slide (1011) to translate along a first direction and for adjusting the position of the rear slide (1011) on the rear chassis (1010) to fit the wheel base of the vehicle; a rear wheel hub (1014) rotatably disposed on the rear wheel hub bracket (1012) and having a rotation axis parallel to the ground for rolling with the rear wheel of the vehicle; a rear wheel hub motor (1015) disposed on the rear wheel hub bracket (1012) and connected to the rear wheel hub (1014) by a rear wheel hub transmission for driving the rear wheel hub (1014); A chassis dynamometer comprising:

5. 5. A chassis dynamometer (10) according to claim 4, Two front wheel hubs (1004) are disposed on each front wheel hub bracket (1002); the front wheel hub transmission (1006) connects the two front wheel hubs (1004) to the front wheel hub motor (1005) and is configured to rotate the two front wheel hubs (1004) synchronously; Two rear wheel hubs (1014) are disposed on each rear wheel hub bracket (1012); A chassis dynamometer characterized in that the rear wheel hub transmission device is configured to connect the two rear wheel hubs (1014) to the rear wheel hub motor (1015) so as to rotate the two rear wheel hubs (1014) synchronously.

6. 5. A chassis dynamometer (10) according to claim 4, Two front wheel hubs (1004) are disposed on each front wheel hub bracket (1002); the front wheel hub transmission (1006) connects the two front wheel hubs (1004) to the front wheel hub motor (1005) and is configured to rotate the two front wheel hubs (1004) synchronously; One rear wheel hub (1014) is disposed on each rear wheel hub bracket (1012); A chassis dynamometer, characterized in that the rear wheel hub transmission is configured to connect the rear wheel hub (1014) to the rear wheel hub motor (1015).

7. 5. A chassis dynamometer (10) according to claim 4, One front wheel hub (1004) is disposed on each front wheel hub bracket (1002); the front hub transmission (1006) is configured to connect the front hub (1004) to the front hub motor (1005); Each of said rear wheel hub brackets (1012) comprises a rear wheel hub (1014); A chassis dynamometer, characterized in that the rear wheel hub transmission is configured to connect the rear wheel hub (1014) to the rear wheel hub motor (1015).

8. A chassis dynamometer (10) according to claim 2 or 3, rotation of the nose wheel test assembly (100) about the vertical is achieved by a passive, active, or fusion method; In the passive method, the steering system of the vehicle provides steering power to drive the front wheels of the vehicle to steer, and the front wheels of the vehicle then drive the front wheel hub (1004) in rolling contact with the front wheels to steer; In the active method, the turning force assist drive device (1003) of the front wheel testing assembly (100) provides steering force and drives the front wheel hub bracket (1002) and the front wheel hub (1004) disposed thereon to rotate about a vertical direction, thereby driving the front wheel of the vehicle in rolling contact with the front wheel hub (1004) and the steering mechanism to steer synchronously; A chassis dynamometer, characterized in that in the fusion method, the control device (103) receives a steering command signal from the steering control system of the vehicle and controls the turning force auxiliary drive device (1003) to follow the steering command signal and provide auxiliary power, thereby driving the front wheel hub bracket (1002) and the front wheel hub (1004) arranged thereon to steer synchronously with the front wheels of the vehicle.

9. A vehicle test bench (1), comprising: A chassis dynamometer (10) according to any one of claims 1 to 8, which is arranged in a pit of a room in which the vehicle test bench (1) is arranged and is substantially flush with the floor of the room; a display device (20) arranged around the chassis dynamometer (10) and configured to display images simulating road environments and scenes in which the vehicle is traveling; an airflow simulation device (30) arranged near the chassis dynamometer (10) and configured to generate an airflow simulating an ambient wind; a temperature control device (40) that is located indoors away from the chassis dynamometer (10) and is used to control the indoor temperature to simulate an ambient temperature; A vehicle test bench comprising:

10. 1. A method for simulating real-world vehicle driving, comprising: Step S101: Park a vehicle on the chassis dynamometer (10) according to any one of claims 1 to 8; Step S102: Adjusting the positions of the front wheel test assembly (100) and the rear wheel test assembly (101) by the control device (103) of the chassis dynamometer (10) so that the front wheels and the rear wheels of the vehicle contact the front wheel hub (1004) and the rear wheel hub (1014), respectively, wherein if two front wheel hubs (1004) are provided on each front wheel hub bracket (1002), the front wheels of the vehicle are fitted between the two front wheel hubs (1004) and the rear wheels of the vehicle contact the rear wheel hub (1014), and if one front wheel hub (1004) is provided on each front wheel hub bracket (1002), the front wheels of the vehicle contact the front wheel hub (1004) and the rear wheels of the vehicle contact the rear wheel hub (1014); Step S103: Fixing the vehicle on the chassis dynamometer (10) by the fixing device (102) so that the vehicle does not move relative to the chassis dynamometer (10) during testing; Step S104: A driver or an automatic driving controller starts the test vehicle and performs operations such as acceleration, deceleration, and steering to simulate road driving; A method comprising:

11. In step S104, If the vehicle is a front-wheel drive vehicle, the movement of the front wheel of the vehicle is transmitted to the front hub transmission (1006) via the front wheel hub (1004), and then transmitted to the front wheel hub motor (1005), and the speed of the rear wheel hub motor (1015) is set according to the speed of the front wheel hub motor (1005) via the control device (103), and the rear wheel is driven to rotate via the rear wheel hub transmission and the rear wheel hub (1014); 11. The method of claim 10, wherein, when the vehicle under test is rear-wheel drive, the movement of the rear wheel of the vehicle is transmitted to the rear wheel hub transmission via the rear wheel hub (1014), and transmitted to the rear wheel hub motor (1015), and the rotational speed of the front wheel hub motor (1005) is set according to the rotational speed of the rear wheel hub motor (1015) via the control device (103), driving the front wheel to rotate via the front wheel hub transmission (1006) and the front wheel hub (1004).

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