Design Of Mobile Manipulator Control System Based On Hybrid Visual Servoing

In recent years,mobile robotic arms have made remarkable achievements in various aspects such as technology and performance,and have further developed towards intelligence,precision,and multifunctionality,which has increased the application value of mobile robotic arms in industrial fields such as logistics transportation and production manufacturing.This paper takes an omnidirectional mobile robotic arm as the research object and,targeting the task of controlling the arm’s end to reach the desired pose,designs an omnidirectional mobile robotic arm visual servo control system based on hybrid visual servo theory and optimization algorithms.The research mainly includes the following four aspects.Firstly,based on the differential equations of robotic kinematics,motion modeling of a six-degree-of-freedom robotic arm and an omnidirectional mobile platform is performed separately.Then,from the perspective of work efficiency,by combining model derivation,the overall kinematic model of the omnidirectional mobile robotic arm is established.In addition,by analyzing the camera imaging principle and binocular disparity principle,the visual system model is completed.This establishes a research foundation for implementing the overall visual servo control of the omnidirectional mobile robotic arm.Secondly,a control system structure based on a hybrid visual servo control law was designed.According to the camera configuration scheme with the eye in hand,the Jacobian matrices of image error and position error are derived separately.By combining image visual servo and position visual servo using adjustable parameter weighting,the complementary advantages are realized.The omnidirectional mobile robotic arm hybrid visual servo control law is obtained by combining the robot kinematic model,and the robot hybrid visual servo system structure is ultimately established.The stability of this system is proven using the Lyapunov function.Thirdly,a method for optimizing the parameters of a hybrid visual servo controller based on an improved bat algorithm was designed.The basic bat algorithm is improved by adopting a chaotic initialization strategy and dynamic parameter strategy,resulting in an improved bat algorithm with better optimization performance.Based on the improved bat algorithm,a controller parameter optimization method is designed and applied to the designed omnidirectional mobile robotic arm hybrid visual servo system,thereby improving the end-effector’s trajectory and allowing the end to reach the desired position along the shortest possible route.Finally,the designed algorithms are experimentally verified and their performances compared using MATLAB’s Robotic Toolbox RTB 9.10 and Machine Vision Toolbox MVTB 10.2.The operability comparison experiment demonstrates the operational advantages of the research object and verifies the correctness of the kinematic modeling.Comparative experiments with other visual servo algorithms show that the hybrid visual servo method proposed in this paper can effectively combine the advantages of image visual servo and position visual servo,maintaining relatively smooth motion trajectories while reducing the risk of target loss.The comparison experiments before and after using the controller parameter optimization algorithm indicate that this parameter optimization method can shorten the end-effector’s trajectory.The experimental results demonstrate the effectiveness of the proposed methods in this paper.