Research On Recognition Of Potholes In Front Of Vehicles And Vibration Reduction Of Suspension Based On Machine Vision

Detection and evaluation of the road environment is an important function of the intelligent vehicle road environment perception system.At present,under the combined action of the driving load and the natural environment,the road service performance gradually declines,and the random potholes on the road surface can reduce the ride comfort and safety of vehicle driving,causing severe vibration of the vehicle body,and seriously affecting the driving comfort of drivers and passengers.In recent years,most of the environment perception algorithms of intelligent vehicles have focused on the detection of vehicles,pedestrians,lane lines,signal lights,etc.on the road,while paying less attention to the state of the road itself.In view of this situation,this paper sets the research object as the road potholes which are less concerned at this stage but have great influence on the ride comfort of vehicles,and focuses on the segmentation and ranging of the potholes in front of vehicles and the vibration reduction methods when vehicles pass through potholes.Aiming at the problems of low segmentation efficiency,poor generalization performance and high resource occupation of the existing pothole region segmentation methods,this paper takes the semantic segmentation network HRNet as the benchmark model,and improves its accuracy and speed by adding convolutional attention module and optimizing the number of residual layers in the feature extraction layer of the network.Through field collection and network search,a large number of pavement pothole images are obtained to establish the pothole data set,and the model training and testing are completed.The test results show that by improving the structure of the segmentation network HRNet,the segmentation effect of the model in this paper reaches 96.3% on the test set,and the reasoning speed of the model reaches42.95 FPS,Compared with similar semantic segmentation algorithms,it has higher segmentation accuracy and speed.Aiming at the problem that the potholes have no fixed shape and are susceptible to changes in pitch angle when measured by camera,an inverse perspective transformation ranging method for camera pitch angle correction and a longitudinal length estimation method for potholes are proposed.The camera pitch angle is estimated by detecting the position of the vanishing point of the road in the image.Then,the road aerial view is generated by the inverse perspective transformation with pitch angle correction.The longitudinal distance between the potholes and the camera and the longitudinal length of the potholes are obtained based on the linear relationship between the pixel coordinate system and the world coordinate system and the pixel coordinates of the potholes in the aerial view.Experimental results show that the method has good measurement accuracy.Based on pothole detection information,the study on suspension preview vibration reduction control for potholes with nowhere to avoid or too late to avoid is carried out.The input model of simulated road surface,semi-active suspension model of 3-DOF 1/4 vehicle and skyhook damper controller are established.In order to realize the suspension pre-aiming control of the pavement pothole,a fuzzy controller with the input of pavement pothole information and vehicle speed information and the output of the maximum damping change of the skyhook damper controller is designed.The smoothness of the vehicle passing through the pothole is improved by adjusting the damping variation range of the skyhook damper controller,and a preview skyhook control strategy is formed.The suspension preview skyhook control strategy was simulated and verified,and the performance comparison is made with the semi-active suspension controlled by the ordinary skyhook and passive suspension under different pothole sizes and vehicle speeds.The simulation results show that the preview skyhook control strategy designed in this paper has generalization for different sizes of potholes and different vehicle speeds.Compared to the ordinary skyhook control,when the vehicle passes through potholes,it can improve the ride comfort index by 8 to 36% while ensuring handling stability.In addition,the suspension preview controller designed in this paper exhibits stable ride comfort improvement effects under different vehicle loads and different pothole depths,which helps to improve the ride comfort of personnel inside the vehicle.