Research On Control Method Of The Rotary Joint Of Mechanical Arm For Underground Mesh Laying

In recent years,the demand for coal resources has been continuously increasing.Currently and in the coming decades,national socio-economic development will still mostly depend on coal resources,which puts forward higher requirements for the efficiency of coal mining.The main factors currently restricting the efficiency of coal mining are that support relies on manual labor,the speed of support is slow,and excavation and support are difficult to be parallel.In view of the problems that most of existed support equipment relies on manual work to complete the mesh laying operation,the support speed is slow,and the risk coefficient is high,an attitude control method for the rotary joint of the mesh laying mechanical arm placed on the rock bolt drill truck is proposed.With this method,the mesh laying work is completed by mechanical arm instead of manual work,and the support speed and efficiency are improved.The main research content of this paper includes:According to the requirements of the underground mesh laying task,the DH parameter method is used to establish the connecting rod model of the mesh laying mechanical arm.By analyzing and comparing commonly used rigid body attitude modeling methods,the unit quaternion method is chosen to establish the attitude model of one rotating joint of the mesh laying mechanical arm.Establish a distributed multijoint control system for specific configurations of multi-rotating joints.Establish the simulation model of rotating joint attitude.The extended state observer for mesh laying control system is designed,and the system model is rewritten into the form of error signal.The total disturbance of the system is treated as an extended state variable,and the estimated value is directly observed by the observer.The convergence of the designed mesh laying control system extended state observer is analyzed.Simulate different working conditions and verify its observation effect by simulation.The feedback control law for the rotary joint control system of mesh laying mechanical arm is designed to form the active disturbance rejection control system together with the attitude model of the controlled rotary joint and the extended state observer.To verify the stability of the designed control algorithm,establish simulation models for single joint control systems and multi-joints distributed control systems.Imitate mesh laying process and verify their control effectiveness by simulation.Establish a rapid control prototype system with using semi physical simulation platform and a physical robotic arm,design experimental plans for single joint and multiple joints,and complete the experiments.The effectiveness of the designed control method has been verified through experiments,and it can improve the system’s antiinterference and response speed to disturbances.In multi-joint experiment,each joint can track the expected information,and the angle tracking effect is good.This paper verifies the designed control method through theoretical analysis,system simulation,and semi physical simulation experiments,proving that the designed control algorithm is feasible for controlling the rotating joint of the robotic arm and can complete the mesh laying task;In the designed distributed multi joint system configuration,each joint has a good tracking effect on the expected information of the system,which proves that the multi joint distributed system configuration designed in this paper is feasible.