Abstract:Aiming at the problems of low control accuracy and frequent steering switching of single-side braking steering track chassis in automatic walking, a three-tangent local path dynamic planning algorithm based on single-side braking steering track chassis was proposed. According to the uncontrollable characteristics of steering braking torque of track chassis, a local path planning method of “steering-straight-steering” was designed. The three-tangent local path dynamic planning algorithm was composed of a straight line and two arcs, the first arc was tangent to the vehicle direction, and the vehicle gradually turned to the target route along the arc. The second straight line was tangent to the two arcs, and the vehicle gradually approached the target route along the straight line. The third section of the arc was tangent to the target course, and the vehicle turned gradually to the target course along the arc. The turning radius of the vehicle was calculated by weighted recursive average filtering through the lateral deviation and heading deviation of the historical movement, and the current stage was judged for adjustment. The results of field automatic straight line driving test showed that in the initial state with a lateral deviation of 0.25m and a heading deviation of 0°, the driving speed of 0.4m/s was advanced. The mean value and standard deviation of the absolute transverse deviation of the algorithm were 0.085m and 0.104m, respectively, which were 23.19% and 19.54% higher than that of the bang-bang algorithm, respectively. The mean value and standard deviation of the absolute course deviation were 3.31°and 3.74°, respectively, which were 25.95% and 25.64% less than that of the bang-bang algorithm, respectively. The total steering control times were 9 times, which was 43.75% less than that of the bang-bang algorithm. The results showed that the three-tangent local path dynamic planning algorithm was suitable for single-side braking steering track chassis, with higher path tracking accuracy and lower control frequency, and can meet the needs of field operations.
