Research On Trajectory Of Multi-axle Steering Control System For ALL-Terrain Cranes

All-terrain crane is modern large-scale construction lifting equipment which has several advantages such as:excellent lifting performance, fast transfer, traveling off-road with load and so on. Multi-axle steering is the key technology of all-terrain crane, decides crane’s handling stability and maneuverability and accessibility. A big error between actual route and theoretic track could be found in practice while all-terrain cranes steering, the error will lead to the all-terrain crane can’t steering in driver’s command.In order to solve this problem, this paper optimizes the steering route with the sliding mode control, establishes the trajectory-tracking model of all-terrain crane which contains the kinematics block of multi-axle vehicle, hydraulic steering system block and sliding mode control block, then simulates several experiments of all-terrain crane steering in different conditions in Matlab\simulink block. In this paper, the research content is as follows:(1) According to the law of Ackerman and kinematics theory, this paper analyzies the motion of all-terrain crane, establishes the motion model of multi-axle vehicle, and obtains the motion equations of vehicle center, the relationship between vehicle steering parameters.(2) The system of symmetrical valve controlled asymmetrical cylinder is compensated by circuit-area method, the hydraulic system of all-terrain crane steering is established with transfer function.(3) This paper studies the sliding mode control, designs the trajectory-tracking controller of all-terrain crane based on sliding mode control with backstepping method.(4) The trajectory-tracking model is established in MATLAB/Simulink to prove the sliding mode control effect on all-terrain crane steering through the simulation; Then set a variety of working conditions, this paper discusses the relationship between the range of first angle, speed and the error for trajectory-tracking of all-terrain crane.