Research On Coordinated Control Of Multi-vehicle Joint Operation Under Eccentric Load

Self-propelled hydraulic truck and its vehicle group is a large-scale transportation equipment,with a large number of wheel groups,large bearing capacity,each wheel group is independently steered by a hydraulic steering mechanism,and the hydraulic truck is realized by the hydraulic system for walking and steering the wheel group Independent driving and control.Unbalanced loading conditions are limited by the existence of extralarge,ultra-long,ultra-wide,and wide-body configurations,and when installed,the center of gravity of the object being carried does not exist at the geometric center of the vehicle body.Multi-vehicle joint operation means that during the transportation of this type of loadbearing equipment,the bearing capacity of a single vehicle is not enough to meet the transportation under this working condition,and the joint operation of multiple transport vehicles is required to achieve coordinated transportation.Due to the deviation of the center of gravity and the existence of heterogeneous fulcrum points,different load forces are caused to the wheels of each truck.Failure to perform drive matching of hydraulic load-carrying wheelsets will result in different axle load forces.Asynchronous movement of the body wheel pairs will not only damage the axles,but also cause uncoordinated multi-vehicle movements.It may even cause the car body to tip over and cause major accidents.Reasonable load driving force matching calculation and drive synchronization optimization calculation are the basis to ensure its normal and efficient operation.There are also requirements for the drive synchronization of non-hard-connected trucks.Under the condition of non-hard-connection,how to maintain the coordinated transportation of multiple vehicles and maintain the reliable walking and steering performance of the carried objects is an urgent problem to be solved.According to the actual requirements of engineering applications and guaranteeing the real-time requirements of the calculation,a synchronous control strategy for multi-vehicle joint coordinated transportation under eccentric loading conditions is proposed.The focus is on the drive synchronous control and steering coordinated control during the coordinated motion process,and the drive model and load force of each wheel set are established.Model;through the planning of the motion path,it is decomposed and converted into a typical motion mode and then solved accordingly,and the pulse train is used to make the vehicle group perform off-load coordinated motion.In the coordinated movement of multiple vehicles,the control theory of unmanned aerial vehicle group formation based on the leader-follower method is studied,and its control theory is applied to the coordinated control of multiple vehicles of hydraulic trucks.The central controller on the leader vehicle calculates the force distribution of the car group,and gives the load force of the bicycle,and then the bicycle controller determines whether the load force is evenly distributed to each wheel group,thereby real-time solution of the wheel load force Calculations and numerical simulations verify the feasibility of the proposed method.The synchronicity of multi-wheel drive and steering drive synergy in the process of coordinated transportation of multi-units under off-load conditions is studied.A coordinated control strategy based on pulsed coordinated steering is proposed.Combined with the model predictive control theory based on the leader-follower control idea and fuzzy PID control,and the two-stage cooperative control method of "wheel-vehicle",numerical simulations verify the feasibility of the proposed method.