Motion Planning And Control Of Automatic Operation Of A Certain Bridge System

This paper proposes a modified artificial potential field method of ellipse influence domain on the basis of the study on the motion planning and control of a bridge system,and applies genetic algrothim and model predictive control method to optimize the system operation trajectory and design the system controller.As a result,the effectiveness of the algorithm,the accurancy of the trajectory planning results and the stability of the control system are verified by the way of co-simulation.The paper is composed of gour parts: part one analyzes the mobile platform by the use of monorail vehicle model,and the Newton-Euler equation is used for dynamic modeling to obtain the yaw dynamics equation of the mobile platform;Modified D-H matrix and Lagrangian equations are used to analyze the kinematics and dynamics of the bridge erection equipment,and obtain the motion constraint equations and dynamic expressions,which can provide support for trajectory planning and optimization,and model predictive controller design.Part two proposes an elliptical obstacle influence domain to tackle the problems of traditional artificial potential field method which is easy to fall into local minimum and the insufficient capacity of narrow passages by dividing the space with the conderation of collision risk level and relative speed.The repulsion field function is optimized and the efficiency of path planning on the mobile platform is improved.Part three establishes the safety margin function according to the dynamic calculation results,and the rated torque of each joint,the genetic algorithm is used to optimize the trajectory,and the curve of the motion state and safety margin of each joint over different time interval is obtained.Then,the calculation result is compared with the actual operation capacity of the system,and the optimal operation time of each step and the expected trajectory of each shutdown are obtained,which provides input parameters for automatic operation motion control.Compared with the original process,the optimized trajectory reduces operating time and improves operating safety.Part four establishes the model predictive controller,and a comprehensive performance function is constructed,and online trajectory planning and tracking control of the mobile platform are also carried out.In order to set the multi-joint PID parameters to achieve better stability,the gravity influence value of each joint during bridge erection is calculated,and a PID position controller with gravity compensation is established.Finally,Car Sim and Adams are used to establish a physical model,and the dynamic simulation is carried out jointly with Matlab.The effectiveness of the mobile platform in avoiding obstacles,and the automatic operation speed of the bridge system are verified under different speed and environment.The results show that the method in this paper gives full play to the performance of the system and realizes the dynamic matching of the motion trajectory to the environment.The trajectory meets the requirements of the automatic operation motion planning and control of the bridge system with less operation time,which has a strong significance for the automatic operation research of other equipment.