Research On Construction And Control Of Coordinated Multi-Robots System

With the advancement of robot technology and the development of its application,the application field of robots is more extensive.Robots are urgently required to perform more and complex tasks,from automated assembly workshops to deep-sea and unmanned operations in space.In order to meet the requirements of task,which is complexity,operational intelligence and system flexibility,it is imperative to develop the application technology of coordinated multi-robots.However,the study of multi-robots coordination has many new problems compared to single robots,such as coordinated form,selection,layout,trajectory planning,and control methods,from the point view of research.In this paper,the construction and control of coordinated multi-robots system is studied for the repeated handling tasks of large and heavy workpieces in automation workshop.According to the task requirements,a reasonable multi-robot coordination system is constructed to improve the utilization rate of a single robot in production.In addition,considering that the trajectory tracking accuracy of a single robot has a significant impact on the control quality of multi-robots system in the form of tight coordination motion,this paper designs reasonable robot control algorithms to improve the trajectory tracking accuracy and anti-interference ability of the robot in repetitive motion control,so as to ensure the consistency of the coordinated motion of multi-robots system.The main contents are summarized as follows:Firstly,aiming at the problem of robots' selection in coordinated multi-robots system,a new idea is proposed in this paper,which is based on the parallel though,and the problem is equivalent to the problem for the selection of parallel robots' branched chains.Through the type synthesis theory of parallel robots,the problem for the freedom selection and placement of the branched robots are solved.Based on this,the C set theory is proposed for the type synthesis of the coordinated multi-robots system and the representation of the position and posture of the robots' base.Then the layout optimization method for the coordinated multi-robots system that has been selected is studied.The minimum layout area,operational cycle time and condition number are taken as the optimized objectives,and the weight ratio of each objective in the task is used.The genetic algorithm and particle swarm optimization(GA-PSO)are used to optimize the layout of each robot to meet the requirements of the task.This method is not only suitable for coordinated multi-robots system,but also for the layout of industrial production lines.In order to plan the trajectory of the coordinated multi-robots system,the modeling problem of multirobots system must be solved first.Therefore,this problem can be transformed into the modeling problem of the parallel robot based on the parallel thought,which will make the multi-robots' modeling simple.For the sake of improving the working efficiency of the system,a time-optimal trajectory planning method is proposed to ensure the rapidity of multi-robots system.When the multi-robots system is in tight coordination,in order to ensure the consistency of the motion coordination,each robot is required to have higher precision in motion control.Compared with the ordinary PD-type iterative learning control,it has faster convergence speed and higher trajectory accuracy.Aiming at the situation that the above-mentioned repetitive control model of the robot is in large nonlinear disturbance,an adaptive sliding mode control based on iterative learning is proposed.An adaptive sliding mode control algorithm with high robustness is added based on iterative learning.Compared with the ordinary PD-type iterative learning control,it has a smoother trajectory and higher trajectory accuracy.The motion control of the coordinated multi-robots system was studied,and a heterogeneous dual 3-PRRR robot system was built.The redundancy of motion coordination is ensured in the hardware design,and the software based on artificial bee colony algorithm to optimize the iterative learning control parameters is designed.The coordinated control of the dual robot system is realized through the completion of the ‘door' type transport experiment.The research work of this paper provides a certain theoretical basis for the research of homogeneous or heterogeneous multi-robots' collaborative work,which can guide the construction and control operation of coordinated multi-robot system in a manner.