Vehicle dynamics simulator and calibration and verification method for vehicle dynamics functions

Abstract

The present invention provides a vehicle dynamic simulator and a method for calibrating and verifying vehicle dynamic functions. The vehicle dynamic simulator includes a manual adjustment module, a main control board, and a slave control board. The main control board includes an acquisition module and a calculation module. The acquisition module is connected to a vehicle bus and the manual adjustment module, respectively, and is used to collect information on the brake pedal opening, the accelerator pedal opening, the vehicle steering angle, the road slope, and the friction coefficient between the tire and the road surface. The calculation module is used to calculate the rotation frequency of the wheel and the acceleration of the vehicle in the five degrees of freedom directions based on the information collected by the acquisition module. The slave control board serves as the physical layer of the simulated wheel speed protocol and the IMU protocol, and sends the rotation frequency to the ABS controller and the acceleration to the airbag controller. The method for calibrating and verifying vehicle dynamic functions is to connect the vehicle dynamic simulator to the ABS controller and the airbag controller of the test vehicle, and perform calibration and verification work when the test vehicle is static or at a low speed.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle testing, and in particular to a vehicle dynamics simulator and a method for calibrating and verifying vehicle dynamic functions. Background Art

[0002] During the vehicle development phase, all functions must be calibrated and validated on test vehicles. Many dynamic functions require calibration and validation under certain vehicle speed and / or acceleration conditions. For example, features like cornering, headlight masking, emergency brake lights, and driver attention reminders often require the vehicle to meet certain dynamic conditions before they can activate.

[0003] The traditional method involves driving a test vehicle on public roads or at a proving ground to perform dynamic function calibration and verification under specific weather conditions (e.g., lighting calibration requires a clear night). However, this method is susceptible to weather and site limitations, and is often impossible to perform in rainy or snowy conditions. Summary of the Invention

[0004] In order to solve at least one aspect of the above technical problems, the present invention provides a vehicle dynamic simulator, which is connected to a test vehicle and can simulate the dynamic changes of the vehicle when the test vehicle is parked statically, so as to carry out calibration and verification of the vehicle's dynamic functions.

[0005] The technical solution adopted in the present invention is:

[0006] In one aspect, a vehicle dynamics simulator is provided, comprising: a manual adjustment module, a main control board and a slave control board; the main control board comprises an acquisition module and a calculation module;

[0007] The acquisition module is connected to the vehicle bus and the manual adjustment module respectively, and is used to collect brake pedal opening information, accelerator pedal opening information and vehicle steering angle information from the vehicle bus, and collect road slope information and friction coefficient information between the tire and the road from the manual adjustment module;

[0008] The calculation module is used to calculate the rotation frequency of the wheel and the acceleration of the vehicle in the five degrees of freedom directions based on the information collected by the collection module;

[0009] The slave control board is respectively connected to the ABS controller and the airbag controller for communication, and serves as a physical layer for simulating the wheel speed protocol and the IMU protocol. It replaces the wheel speed sensor to send the rotation frequency calculated by the calculation module to the ABS controller, and replaces the IMU sensor to send the acceleration calculated by the calculation module to the airbag controller.

[0010] Furthermore, the calculation module includes a power model, a tire model, a steering model, a suspension model and a body model;

[0011] The power model is used to calculate the driving force and braking force of the vehicle based on the brake pedal opening information and the accelerator pedal opening information collected by the collection module;

[0012] The tire model is used to calculate the rotation frequency of each wheel based on the set damping, stiffness, slip rate and geometric parameters of the tire, the driving force and braking force calculated by the power model, and the road slope information and friction coefficient information collected by the collection module;

[0013] The steering model is used to calculate the angle of each wheel and the turning radius of the vehicle based on the vehicle steering angle information collected by the collection module;

[0014] The suspension model is used to calculate the mutual force between the tire and the vehicle body according to the geometric parameters, spring stiffness and damping coefficient of the vehicle suspension;

[0015] The vehicle body model is used to calculate the acceleration of the vehicle in the five degrees of freedom directions based on the set geometric parameters, vehicle body stiffness and weight distribution of the vehicle body, and the calculation results of the tire model, the steering model and the suspension model.

[0016] Furthermore, the manual adjustment module includes a road slope knob and a friction coefficient knob, the road slope knob is used to manually adjust the road slope value, and the friction coefficient knob is used to manually adjust the friction coefficient value.

[0017] Furthermore, the vehicle dynamics simulator also includes a shell, the manual adjustment module, the main control board and the slave control board are arranged in the shell, and a display screen is provided on the shell, and the display screen is connected to the manual adjustment module and the main control board respectively.

[0018] Furthermore, the wheel speed protocol is an AK protocol, and the IMU protocol is an SPI bus protocol.

[0019] On the other hand, a method for calibrating and verifying vehicle dynamic functions is provided, in which the above-mentioned vehicle dynamic simulator is connected to the ABS controller and airbag controller of the test vehicle through a wiring harness, and calibration and verification are performed when the test vehicle is statically parked or at a low speed.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] The present invention features a compact and portable design, convenient and time-saving manual installation and disassembly. It is plug-and-play, requires no configuration, and is easy to use. Practice has proven that both installation and disassembly take less than a minute. It can be used with the vehicle both stationary and in motion. Operation is simple, and speed adjustment can be achieved using the accelerator and brake pedals, consistent with normal driving habits. It is compatible with a wide range of vehicle models, requiring only different wiring harnesses. The vehicle dynamics simulator is a dedicated device, a self-contained minimal system, and offers low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 A schematic structural diagram of a vehicle dynamics simulator according to an embodiment of the present invention is shown;

[0024] Figure 2 A schematic diagram showing a vehicle dynamics simulator according to an embodiment of the present invention;

[0025] Figure 3 A schematic diagram of a vehicle dynamics calculation architecture of a vehicle dynamics simulator according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0026] The above and other technical features and advantages of the present invention are described in more detail below with reference to the accompanying drawings.

[0027] As used herein, the term "including" and its variations mean open inclusion, ie, "including but not limited to." Unless otherwise stated, the term "or" means "and / or." The term "based on" means "based, at least in part, on."

[0028] On a real vehicle, vehicle dynamics are primarily expressed as speed and acceleration in all five degrees of freedom: X-axis acceleration (longitudinal), Y-axis acceleration (widthwise), Z-axis acceleration (heightwise), angular acceleration about the X-axis, and angular acceleration about the Z-axis. Angular acceleration about the Z-axis is generally not used, so the five degrees of freedom are considered. Vehicle speed is sensed by the ABS controller, while the five degrees of freedom acceleration are sensed by the airbag controller.

[0029] The ABS controller senses vehicle speed as follows: Wheel speed sensors are installed on each of the vehicle's four wheels. These sensors detect wheel rotation and, through a communication protocol, transmit the rotational frequency to the ABS controller. The ABS controller then calculates vehicle speed based on the wheel diameter and sends this speed to the vehicle bus for use by other controllers. The airbag controller, in turn, uses the IMU sensor to sense acceleration in all five degrees of freedom.

[0030] In one aspect, the present invention provides a plug-and-play vehicle dynamics simulator. Figure 1 As shown, the physical structure consists of simulator box 1 and wiring harness 2. One end of wiring harness 2 is connected to simulator box 1, while the other two ends are connected to the ABS controller and airbag controller. The vehicle dynamics simulator replaces the four wheel speed sensors and IMU sensors. The vehicle dynamics simulator transmits the wheel rotation frequency to the ABS controller according to the wheel speed sensor protocol and transmits the vehicle's five degrees of freedom acceleration signals to the airbag controller according to the IMU chip protocol. When wiring harness 2 is connected to the controller, the wheel speed sensors and IMU sensors must be physically disconnected from the controller.

[0031] In a specific embodiment, Figure 1 、 Figure 2 As shown, the vehicle dynamics simulator includes a main control board and a slave control board disposed within a simulator box 1. It also includes a manual adjustment module, which includes a road slope knob 3 and a friction coefficient knob 4 mounted on the simulator box 1. Rotating the road slope knob 3 manually adjusts the road slope value, while rotating the friction coefficient knob 4 manually adjusts the friction coefficient value. The simulator box 1 also includes a display screen 5, which is connected to the manual adjustment module and main control board, and is used to display information such as road slope, friction coefficient, and wheel speed.

[0032] The main control board includes an acquisition module and a calculation module. The acquisition module is respectively connected to the vehicle bus and the manual adjustment module. The acquisition module is responsible for reading vehicle bus signals such as CAN, Lin, and Flexray to obtain the vehicle's brake pedal opening information, accelerator pedal opening information, and vehicle steering angle information. In addition, it is also responsible for collecting road slope information and tire-road friction coefficient information from the manual adjustment module. Preferably, the connection between the wiring harness 2 and the ABS controller can monitor vehicle bus signals. The calculation module is used to calculate the vehicle posture, that is, to calculate the wheel rotation frequency and the acceleration of the vehicle in the five degrees of freedom directions.

[0033] The slave control board is respectively connected to the ABS controller and the airbag controller. The slave control board serves as the physical layer for implementing the wheel speed protocol and the IMU protocol. It simulates the four wheel speed sensors and the IMU sensor, and includes a transceiver and a voltage and current conditioning module. Currently, the AK protocol is widely used in wheel speed sensors. The difficulty in simulating the AK protocol lies in the fact that the physical layer uses three-level encoding. A dual-channel superposition solution can be used. At the same time, in order to ensure the synchronization of the dual-channel superposition, the single-chip microcomputer interrupt mechanism is used to implement it. Currently, the SPI bus protocol is widely used in IMU sensors. The difficulty in simulation lies in the fact that the content of the interaction between the IMU sensor and the airbag controller is not public. The present invention summarizes several interaction templates based on project experience. The vehicle dynamic simulator can monitor the communication between the IMU sensor and the airbag controller, and select the corresponding interaction template to implement protocol pairing.

[0034] like Figure 3 As shown in Figure 1, the calculation module consists of a power model, a chassis model, and a body model. The chassis model consists of a tire model, a steering model, and a suspension model.

[0035] The power model is used to calculate the driving force and braking force of the vehicle based on the brake pedal opening information and accelerator pedal opening information collected by the acquisition module.

[0036] The tire model sets the tire's damping, stiffness, slip ratio, and geometric parameters. Based on these settings, the driving and braking forces calculated by the dynamic model, and the road slope and friction coefficient information collected by the acquisition module, the tire model calculates the rotational frequency of each wheel.

[0037] The steering model is used to calculate the angle of each wheel and the turning radius of the vehicle based on the vehicle steering angle information collected by the acquisition module.

[0038] The suspension model is used to calculate the interaction force between the tire and the vehicle body based on the geometric parameters, spring stiffness, and damping coefficient of the set vehicle suspension.

[0039] The body model sets the body's geometric parameters, body stiffness, and weight distribution. The body model comprehensively calculates the acceleration of the body in five degrees of freedom based on the above settings and the calculation results of the chassis model.

[0040] In another aspect, the present invention provides a method for calibrating and verifying vehicle dynamic functions. During the vehicle development phase, when calibrating and verifying vehicle dynamic functions, a simulator box 1 is connected to the ABS controller and airbag controller of a test vehicle via a wiring harness 2. Accelerator and brake pedal signals are used as inputs, and vehicle dynamics simulation calculations are performed to determine the vehicle's dynamic state. This state is then fed back to the ABS and airbag controllers, thereby achieving vehicle dynamic simulation. Simulations can then be performed and functions activated according to dynamic function requirements while the test vehicle is parked or operating at a low speed, unaffected by weather or site restrictions.

[0041] The above are only preferred embodiments of the present invention and are illustrative rather than restrictive. The structures and connection methods of the various components in the present invention are subject to change. Any equivalent transformations and improvements based on the technical solution of the present invention should not be excluded from the scope of protection of the present invention.

Claims

1. A vehicle dynamics simulator, characterized in that: include: Manual adjustment module, main control board and slave control board; the main control board includes an acquisition module and a calculation module; The acquisition module is connected to the vehicle bus and the manual adjustment module respectively, and is used to collect brake pedal opening information, accelerator pedal opening information and vehicle steering angle information from the vehicle bus, and collect road slope information and friction coefficient information between the tire and the road from the manual adjustment module; The calculation module is used to calculate the rotation frequency of the wheel and the acceleration of the vehicle in the five degrees of freedom directions based on the information collected by the collection module; The slave control board is respectively connected to the ABS controller and the airbag controller, and serves as a physical layer for simulating the wheel speed protocol and the IMU protocol. It replaces the wheel speed sensor to send the rotation frequency calculated by the calculation module to the ABS controller, and replaces the IMU sensor to send the acceleration calculated by the calculation module to the airbag controller. The vehicle dynamic simulator is composed of a shell and a wiring harness. One end of the wiring harness is connected to the shell, and the other two ends of the wiring harness are connected to the ABS controller and the airbag controller respectively.

2. A vehicle dynamics simulator as claimed in claim 1, characterized in that: The calculation module includes a power model, a tire model, a steering model, a suspension model and a body model; The power model is used to calculate the driving force and braking force of the vehicle based on the brake pedal opening information and the accelerator pedal opening information collected by the collection module; The tire model is used to calculate the rotation frequency of each wheel based on the set damping, stiffness, slip rate and geometric parameters of the tire, the driving force and braking force calculated by the power model, and the road slope information and friction coefficient information collected by the collection module; The steering model is used to calculate the angle of each wheel and the turning radius of the vehicle based on the vehicle steering angle information collected by the collection module; The suspension model is used to calculate the interaction force between the tire and the vehicle body based on the geometric parameters, spring stiffness and damping coefficient of the vehicle suspension; The vehicle body model is used to calculate the acceleration of the vehicle in the five degrees of freedom directions based on the set geometric parameters, vehicle body stiffness and weight distribution of the vehicle body, and the calculation results of the tire model, the steering model and the suspension model.

3. A vehicle dynamics simulator as claimed in claim 1, characterized in that: The manual adjustment module includes a road slope knob and a friction coefficient knob. The road slope knob is used to manually adjust the road slope value, and the friction coefficient knob is used to manually adjust the friction coefficient value.

4. A vehicle dynamics simulator as claimed in claim 1, characterized in that: The manual adjustment module, the main control board and the slave control board are arranged in the shell. A display screen is provided on the shell. The display screen is connected to the manual adjustment module and the main control board respectively.

5. A vehicle dynamics simulator as claimed in claim 1, characterized in that: The wheel speed protocol is the AK protocol, and the IMU protocol is the SPI bus protocol.

6. A method for calibrating and verifying vehicle dynamic functions, characterized in that: The vehicle dynamic simulator as claimed in any one of claims 1 to 5 is connected to the ABS controller and the airbag controller of the test vehicle through a wiring harness, and calibration and verification are performed when the test vehicle is parked statically or at a low speed.

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