Test Experimental Study On The Measurement Method Of Tire Steering Angle And Slip Angle Based On Machine Vision

Steering angle and slip angle of vehicle tires are important parameters of vehicle motion control system when observing vehicle movement state and estimating vehicle movement stability, and the precision of vehicle motion control was affected by observing them accurately and real-time. This paper explored the measuring method to slip angle and steering angle of tires using a non-contact optical image processing method. The research provides an effective means to motion control algorithm verification and control performance evaluation, has important theoretical and practical application value.The primary works of the paper are summarized as follows:(1) The needs of tire steering angle and slip angle measurement technology based on machine vision were analyzed, hardware systems, including GPS system, sensor module, data acquisition module, were built based on image capture and real-time controller CVS-1456. And selected the LabVIEW and IMAQ Vision toolkit as the test system software development platform.(2) The measuring principle of obtaining tire slip angle based on machine vision was explored. During in the measurement of tire steering angle, we divided and filtered the original test plate image. The color model of original images were analyzed, and according to the R-G color features, realized extraction of edge image of the test plate using histogram threshold segmentation method. Do edge detection of plate edges based on Canny algorithm, the detection of plate edge is approximately a straight line on the projection of horizontal plane, and the intersection angle of the straight line and longitudinal plane of the body is treated as steering angle.(3) The measuring principle of obtaining tire steering angle based on machine vision was explored. During in the measurement of tire slip angle, changed the tires reduced to a two-degree-of-freedom linear model, got the road image, extracted the road characteristic as characteristics input of algorithm called PLK, and use motion estimation method to calculate the wheel slip angle based on LabVIEW programming.(4) The roadway test of measuring tire steering angle directly based on machine vision was carried, which include in-situ static test and real vehicle dynamic test. The test verified the reliability and stability of the image acquisition on the front wheel Angle.