Joint simulation method and system for vehicle carrying ACC and ESC

Abstract

The invention provides a vehicle joint simulation method and system carrying ACC and ESC. The method depends on a dynamics simulation platform of CarSim software, and vehicle dynamics models of ACC and ESC are integrated; secondly, a multi-dimensional traffic scene is built based on PreScan, various typical road networks are fused, variable illumination (day and night / rain and snow) and intelligent road facilities are integrated, and environment sensing data are generated through a camera, a millimeter wave radar and a laser radar multi-mode sensor; and finally, a simulation system is built in Simulink, real-time data interaction with vehicle dynamics and environmental perception is realized through an S-Function interface, and system verification including a decision planning algorithm and a sensor fusion model is built. According to the invention, a basis example is provided for verifying the joint effect between the ADAS, and through the combined use of a plurality of simulation software, the defects between the simulation software are effectively avoided, so that the data is more real and credible, and meanwhile, the safety problem and the economic cost of a real vehicle experiment are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent driving simulation, and in particular, relates to a vehicle co-simulation method and system equipped with ACC and ESC. Background Art

[0002] At present, the regulations for driverless are yet to be improved. Before the technology becomes mature, developing advanced driver assistance systems (ADAS) is the key to realizing intelligent driving. ADAS uses devices such as vision sensors, GPS, millimeter-wave radars, and lidar to monitor the driving environment in real time, identify and track surrounding objects, and analyze them in combination with GPS data to warn of potential risks or control the vehicle, improving driving safety and comfort. With the development of technologies such as 5G technology, high-precision maps, and various sensors, it becomes possible for more and more autonomous driving vehicles equipped with ADAS to be on the road.

[0003] Currently, the research on ADAS mainly focuses on the Adaptive Cruise Control (ACC), and there is less research on the combined effects between multiple assistance driving systems. However, in order to simulate various road scenarios, current vehicles are equipped with multiple assistance driving systems. ACC is a longitudinal driving assistance system based on sensors and intelligent control. By monitoring the vehicle or road conditions ahead in real time, it automatically adjusts the vehicle speed to maintain a safe distance or drive at a set speed. Its core goal is to reduce the driver's operation burden, improve driving safety, and optimize the fuel efficiency of the vehicle in the cruise state.

[0004] The Electronic Stability Control (ESC) monitors the driving state of the vehicle. When understeering or oversteering occurs during emergency obstacle avoidance or turning, it enables the vehicle to avoid deviating from the ideal trajectory. Simply put, it is an active intervention safety system that prevents the vehicle from skidding and causing out-of-control, rollover, oversteering, or understeering in emergency situations, which can improve the vehicle's handling performance and driving safety.

[0005] Most of the research on assistance driving systems is based on some simulation software. However, the simulation software on the market has its own advantages and disadvantages. For example, PreScan is prominent in road model establishment and sensor configuration, but its vehicle model is relatively simple with insufficient degrees of freedom; CarSim's vehicle model has more degrees of freedom, and the vehicle kinematic and dynamic parameters are complete and convenient to output. However, its simulation of the intelligent driving system has problems such as low accuracy and large jitter. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a vehicle co-simulation method and system equipped with ACC and ESC.

[0007] The present invention adopts the following technical solutions to solve the above technical problems:

[0008] A vehicle co-simulation method equipped with ACC and ESC, characterized by comprising the following steps:

[0009] First step: Construct a vehicle dynamics model integrating adaptive cruise control and electronic stability control in the vehicle dynamics simulation platform CarSim, and configure the vehicle's dynamics parameters, sensor parameters and control strategies.

[0010] Second step: Build a multi-dimensional road scene in the scene modeling engine PreScan, including dynamic traffic flow, variable lighting conditions and intelligent road facilities; import the vehicle dynamics model into the road scene and configure the perception data of multi-modal sensors.

[0011] Third step: Establish a simulation system in the Simulink software to realize the real-time interaction of vehicle dynamics data and environmental perception data.

[0012] Use the simulation system to simulate vehicle autonomous driving. Output the yaw rate, center of mass sideslip angle and tire slip ratio of the vehicle through CarSim, generate multi-sensor data streams by PreScan, and Simulink synchronously display control instructions and system states.

[0013] Further, in the first step, the configuration of the vehicle dynamics model includes:

[0014] Adopt a 13-degree-of-freedom non-linear vehicle dynamics model, configure the cornering stiffness and friction coefficient of the Pacejka tire model, set the engine torque curve, transmission ratio and hydraulic braking response time, and activate the two-channel ABS and ESC rollover prevention threshold parameters.

[0015] Further, in the second step, the construction of the multi-dimensional road scene includes:

[0016] In PreScan, construct a low-adhesion road surface and sharp bend scene through the Road Editor, add dynamic traffic participants, configure the detection range and field of view angle of millimeter-wave radar, camera and lidar, and fuse multi-source sensor data through the Sensor Fusion module.

[0017] Further, the construction of the simulation system includes:

[0018] Design a safety distance model and acceleration limit for the ACC following vehicle strategy in Simulink, configure the lateral acceleration and roll angle thresholds of ESC, and achieve the time step synchronization and cross-platform data alignment of CarSim, PreScan, and Simulink through the FMU co-simulation mechanism.

[0019] A vehicle co-simulation system equipped with ACC and ESC, characterized by comprising:

[0020] Vehicle dynamics module: A 13-degree-of-freedom vehicle model integrating ACC and ESC built based on CarSim, configured with a non-linear tire model and braking system parameters;

[0021] Scenario simulation module: A multi-dimensional traffic scenario built based on PreScan, including dynamic traffic flow, variable environmental conditions, and multi-sensor fusion data interfaces;

[0022] System verification module: A co-simulation framework based on Simulink, integrating vehicle dynamics data, environmental perception data, and control algorithms through S-Function or FMU interfaces to achieve the collaborative verification and visual analysis of ACC and ESC.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] Through the interaction of multiple simulation software, this method studies the combined effects between multiple assisted driving systems, achieving a more comprehensive intelligent driving simulation. Description of the Drawings

[0025] Figure 1 is the overall flowchart;

[0026] Figure 2 is the vehicle model diagram built in CarSim;

[0027] Figure 3 is the road scenario diagram designed in PreScan;

[0028] Figure 4 is the simulation schematic diagram in Simulink. Specific Embodiments

[0029] The following presents specific embodiments in conjunction with the drawings. The specific embodiments are only used to introduce the technical solutions of the present invention in detail and do not limit the protection scope of this application.

[0030] The present invention provides a vehicle co-simulation method equipped with ACC and ESC, including the following steps:

[0031] Step 1: In the vehicle dynamics simulation platform CarSim, considering the vehicle parameters affected by the ACC and ESC systems, construct a vehicle dynamics model integrating Adaptive Cruise Control (ACC) and Electronic Stability Control (ESC).

[0032] Step 2: Based on the PreScan scenario modeling engine, construct various different road scenarios; import the vehicle dynamics model into the road scenarios, and configure various sensors such as cameras, millimeter-wave radars, and lidar for the vehicle;

[0033] Simulate the driving scenarios by changing road infrastructure (traffic lights / marking / roadblocks), variable lighting conditions (day / night / rain / snow), etc.

[0034] Step 3: Build a simulation system in Simulink, and realize real-time data interaction with CarSim (vehicle dynamics) and PreScan (environmental perception) through the S-Function interface;

[0035] CarSim outputs 15 dynamic parameters such as yaw rate and sideslip angle of the center of mass in real time; PreScan generates multi-sensor data containing semantic information of the target object; the Simulink visualization interface synchronously displays the control instruction generation process and the system state transition matrix, realizing spatio-temporal alignment and comparative analysis of cross-domain data.

[0036] Figure 2 This is the configuration of the dynamics model of the vehicle equipped with ACC and ESC systems in CarSim provided by the embodiment of the present invention. This model configuration mainly includes:

[0037] Define basic parameters such as vehicle type, wheelbase, mass distribution, and suspension stiffness in the vehicle parameter interface of CarSim. It is necessary to ensure that the 13-degree-of-freedom characteristics of the vehicle dynamics model (including longitudinal, lateral, vertical motions, and tire dynamics) accurately reflect the characteristics of the real vehicle. Select the non-linear Pacejka tire model, configure parameters such as tire cornering stiffness and friction coefficient to ensure the simulation accuracy of the vehicle's grip under complex working conditions; set the engine torque curve, transmission ratio, hydraulic brake system response time, etc. to ensure the longitudinal acceleration control accuracy; configure parameters such as the detection range of the forward radar in the sensor module of CarSim to support dynamic adjustment to adapt to the cornering scenario; enable two-channel ABS in the brake system interface of CarSim, set the maximum braking pressure and the minimum activation pressure, and ensure that the engine throttle automatically returns to zero when ESC is activated. Configure ESC rollover prevention parameters: lateral acceleration threshold, roll angle threshold. Heavy vehicles need to additionally set the predicted lateral acceleration to trigger braking intervention.

[0038] Build the ACC algorithm in Simulink, interact with CarSim in real time through the S-Function interface, input the distance to the vehicle ahead and the relative speed, and output the desired acceleration command. Set the following vehicle-following strategy parameters: safety distance model (such as fixed time interval or dynamic adjustment), acceleration limit, and monitor the control command generation process through the Simulink visualization interface.

[0039] In PreScan, for various different driving road scenarios built for this co-simulation system, one of the road scenarios is as Figure 3 , and the construction of various different road scenarios mainly includes:

[0040] Replace the default vehicle model with the high-precision CarSim model; in the Experiment of Prescan, select the dynamic model type of the actuator (Actor) as User-Specified Model, and import the vehicle dynamics model generated by CarSim through the Simulink interface (such as S-Function module or FMU file); ensure that the output signals of the CarSim model (such as yaw rate, sideslip angle of the center of mass, tire vertical displacement, etc.) match the dynamic interface of Prescan.

[0041] Coordinate system alignment and parameter synchronization; in the Object Configuration of Prescan, set the initial position of the vehicle to align with the Galilean coordinate system of CarSim to avoid the deviation of the motion trajectory caused by coordinate system differences. Synchronize vehicle parameters: mass distribution, wheelbase, tire stiffness, etc. need to be consistent with the CarSim model.

[0042] Function verification scenario construction; dynamic traffic flow and complex road design, use the Road Editor of Prescan to build low-adhesion road surfaces (such as ice and snow, wet and slippery) and sharp curve scenarios to test the yaw stability control of the simulated vehicle; add dynamic traffic participants (such as cutting-in vehicles, pedestrians) to simulate the response sensor signals and vehicle state feedback of the system vehicle in emergency obstacle avoidance.

[0043] Set virtual sensors in Prescan to output parameters such as vehicle yaw rate and roll angle to Simulink for real-time correction of the system vehicle controller; use the Batch Processing function of CarSim to batch test the ESC activation thresholds under different road surface friction coefficients.

[0044] Figure 4 This is a schematic diagram of the co-simulation of the simulated vehicle in Simulink provided by this embodiment, and the main contents include:

[0045] Complete the vehicle dynamics model configuration in CarSim (such as ACC / ESC parameters, tire model, braking system, etc.). Generate the simfile.sim file through the Send to Simulink function. This file contains the interface information of the vehicle dynamics model.

[0046] Build the road scene in PreScan (such as curves, dynamic traffic flow), add vehicles and set the dynamics model type to User-Specified Model. Replace the default model with the test_1_cs.slx file generated by CarSim to ensure coordinate system alignment. Configure sensors (such as millimeter-wave radar, camera), set parameters such as detection range, field of view angle, etc., and fuse multi-sensor data through the SensorFusion module.

[0047] Create a new model in Simulink, drag in the CarSim S-Function module, and link it to the simfile.sim file to ensure that the input and output interfaces are consistent with the CarSim model definition.

[0048] Generate the Simulink model framework (such as Experiment_1_cs.slx) through the Parse&Build function of PreScan, and input the scene data (such as road topology, traffic participant positions) into Simulink in the form of signals. Connect the sensor signals of PreScan (such as the distance to the vehicle in front detected by the radar) to the control algorithm module in Simulink.

[0049] Design the ACC / ESC control algorithm in Simulink. The input is the sensor data of PreScan and the vehicle state of CarSim, and the output is the control instruction. Ensure that the simulation frequencies of CarSim, PreScan, and Simulink are the same, and configure the time step to 10 ms to balance accuracy and efficiency. Use the FMU co-simulation mechanism to achieve cross-platform data synchronization, and monitor signal delay or loss problems through the Data Inspector of Simulink.

[0050] Click Run in Simulink to start the co-simulation. CarSim outputs the dynamics parameters in real time (such as yaw rate, tire slip ratio), PreScan generates sensor data, and Simulink synchronously displays the control instruction and system state. Observe the vehicle trajectory in the 3D scene through the VisViewer of PreScan to verify the ACC following or ESC stability control effect.

[0051] Export simulation data (such as vehicle speed, acceleration, braking pressure) to a CSV file and perform post-processing using MATLAB scripts. Batch run different parameter combinations through Batch Processing to optimize control performance.

[0052] Where the present invention is not described shall apply to the prior art.

Claims

1. A vehicle co-simulation method with ACC and ESC, characterized in that It includes the following steps: The first step: Build a vehicle dynamics model integrating adaptive cruise control and electronic stability control in the vehicle dynamics simulation platform CarSim, and configure the vehicle's dynamics parameters, sensor parameters, and control strategies; The second step: Build a multi-dimensional road scene in the scene modeling engine PreScan, including dynamic traffic flow, variable lighting conditions, and intelligent road facilities; Import the vehicle dynamics model into the road scene and configure the perception data of multi-modal sensors; The third step: Establish a simulation system in Simulink software to realize the real-time interaction of vehicle dynamics data and environmental perception data; Use the simulation system to simulate vehicle autonomous driving. Output the yaw rate, center of mass side slip angle, and tire slip rate of the vehicle through CarSim, generate multi-sensor data streams by PreScan, and Simulink synchronously displays control instructions and system status.

2. The vehicle co-simulation method with ACC and ESC according to claim 1, characterized in that In the first step, the configuration of the vehicle dynamics model includes: Adopt a 13-degree-of-freedom non-linear vehicle dynamics model, configure the cornering stiffness and friction coefficient of the Pacejka tire model, set the engine torque curve, transmission ratio, and hydraulic brake response time, and activate the two-channel ABS and ESC rollover prevention threshold parameters.

3. The vehicle co-simulation method with ACC and ESC according to claim 1, characterized in that, In the second step, the construction of the multi-dimensional road scene includes: Build a low-adhesion road surface and sharp turn scene in PreScan through the Road Editor, add dynamic traffic participants, configure the detection range and field of view angle of millimeter-wave radar, camera, and lidar, and fuse multi-source sensor data through the Sensor Fusion module.

4. The co-simulation method according to claim 1, wherein In the third step, the construction of the simulation system includes: Design a safety distance model and acceleration limit for the ACC following strategy in Simulink, and configure the lateral acceleration and roll angle thresholds of ESC. Realize the time step synchronization and cross-platform data alignment of CarSim, PreScan, and Simulink through the FMU co-simulation mechanism.

5. A vehicle co-simulation system equipped with ACC and ESC, characterized in that, It includes: Vehicle dynamics module: A 13-degree-of-freedom vehicle model integrating ACC and ESC based on CarSim, configured with a non-linear tire model and brake system parameters; Scene simulation module: A multi-dimensional traffic scene built based on PreScan, including dynamic traffic flow, variable environmental conditions, and multi-sensor fusion data interface; System verification module: A co-simulation framework based on Simulink, integrating vehicle dynamics data, environmental perception data, and control algorithms through S-Function or FMU interfaces to realize the collaborative verification and visualization analysis of ACC and ESC.

Images