Research Of Leveling Control System Of Heavy Duty Flat Vehicle

With the development of the national economy, the number and tonnage requirements of the domestic heavy-duty hydraulic flatbed vehicles are required more. However, the current domestic heavy-duty hydraulic flatbed vehicles can only meet the basic requirements of the action. Some properties can not be well satisfied. Therefore, it is significant to improve the accuracy of leveling control for improving the whole properties of domestic heavy-duty hydraulic flatbed vehicles.In this paper, automatic leveling control system is studied which is commonly used in engineering heavy flatbed vehicles, including control strategy in the electrical system and hydraulic control system. Combined with the current situation at home and abroad for heavy platform leveling system research and the usage of heavy vehicles, such as working conditions, automatic leveling system for heavy flatbed vehicles is analyzed and improved to ensure the safe operation of heavy vehicles in the work process.For the existing problems of leveling control methods commonly used at home and abroad, such as the problem of "virtual leg" is not completely solved or not ideal, the leveling time is too long time, and so on, a kind of new leveling control way named “flat chasing style” leveling strategy is proposed on the basis of the current common location-based error method, which can reduce the rate of "virtual leg" phenomenon in the leveling process and can shorten the leveling time. In order to make the leveling control more precisely, the hydraulic system combined of load sensing pump and multi-way valve which is with a pressure compensating valve before is adopted, which make up of load sensing hydraulic control system. The usage of load sensing pump saves energy for the system effectively, and the usage of multi-valve makes the system having good speed stiffness. As the pressure compensating valve makes the pressure before and after the multi-valve constant, which makes the control of the flow of suspension cylinders and the piston displacement control more accurate. Fuzzy PID is adopted as the control strategy considering the nonlinear, time-varying, energy-saving and big outside interference of the research object. Finally, hydraulic system of leveling control system is built through AMESim, and leveling control method and fuzzy PID control section are built through MATLAB/ Simulink. Co-simulation interface is used to exchange the two parts of data to verify the feasibility of the entire leveling control system and advancement. And the accuracy of this article leveling control system is verified through the 100 T flatbed conducted experiments.