Research On Active Control Theory And Key Technology Of Truck Crane Outrigger System In Time-varying Operations

The outrigger system is an important part of the truck crane.Whether in the horizontal erection stage before crane operation or in the chassis posture maintenance during operation,it is necessary to rely on the leg system to achieve.However,the coupling bearing characteristics of the outrigger system constraints,the automatic leveling of the outrigger system above four outriggers is slow to develop,especially when the active control technology in the operation is still blank.In response to this situation,this paper takes the truck crane as the research object,the automatic leveling of the outrigger system before the operation of any redundancy degree,and the active control theory and technology during the operation for preliminary exploration.The main work of the full paper is as follows.(1)Theoretical research on the automatic leveling of the outrigger system under initial working conditions.Firstly,the conventional leveling scheme based on the rigid body coordinate transformation theory and its shortcomings is investigated.Then,the automatic leveling method based on the "order reducing" proposed by the team is explained,which converts the super-stationary problem into a stationary problem and solves the problems of "virtual outrigger" and repeated iterations in the traditional leveling process.Finally,the team introduces the coupled geometry and load leveling theory which considers the coupled loading characteristics of the outrigger system.The coupled leveling theory is the basis for the automatic leveling of the outrigger system with arbitrary redundancy,which can optimize the load while controlling the inclination angle in the leveling process,and is also the premise for the construction of the active control theory in the next chapter.(2)The active control theory of the outrigger system under time-varying working conditions is studied.Firstly,the active control theory of the geometric attitude of the outrigger system based on the coordination relationship of rigid chassis deformation is described and the corresponding control strategy is constructed to initially achieve the goal of real-time control of chassis attitude in time-varying operation of the truck crane.Then,drawing on the geometry and load coupling leveling theory,combined with the active control concept,the geometry,and load coupling active control theory of the outrigger system is constructed,with the control strategy to achieve the geometry and load optimization of the outrigger system in real-time.(3)Numerical simulation verification of automatic leveling and active control theory.Firstly,the numerical simulation of traditional leveling and coupled leveling theory is carried out,and the comparison of the simulation results shows that the coupled control model can optimize the angle of the platform and the load of the outriggers at the same time.Secondly,two active control models are simulated and analyzed respectively,and the results show that the geometric active control can better maintain the horizontal attitude of the chassis in the top loading time change operation,while for the six-point outrigger system,the coupled active control model can control the geometric attitude and the outrigger load simultaneously.(4)The active control platform of the outrigger system is upgraded and experimentally verified.First,the six-point outrigger system experimental platform was upgraded based on the original electromechanical four-point outrigger system experimental platform.Then,traditional leveling experiments,automatic leveling experiments based on the "order reducing" and geometry-load coupling leveling experiments were carried out with the experimental platform.Finally,the geometric active control experiment and the coupled active control experiment were carried out.The experimental results confirm the correctness of the proposed theory and strategy.In this paper,the automatic leveling and active control of the truck crane outrigger system is studied from theoretical,simulation,and experimental aspects,forming an active control scheme of geometric attitude and outrigger load for the whole operation cycle of the outrigger system with arbitrary redundancy,which is of great value to improve the operational safety,stability,and efficiency of the truck crane and can be transferred to other outrigger system equipped with concrete pump truck,missile launcher,etc.special vehicles equipped with outrigger systems.