Dynamic Modeling And Force-free Coordinated Drag Control Of Redundant Dual-arm Industrial Robots

The dual-arm robot is widely used in all kinds of occasions because it has high flexibility and large working space utilization due to its human-like arm structure compare with single arm robot.Focused on robot modeling and joint driving torque,the dynamic modeling and coordinated drag control of redundant dual-arm industrial robots are systematically studied.Taking the domestically developed dual-arm robot as the research object,the robot control software based on the Linux+Xenomai dual-core real-time multi-tasking platform is discussed and designed and the kinematics and dynamics models are established.First,the base coordinate system of the double-arm is calibrated and the D-H model of the single-arm is established.The concept of arm angle is introduced to complete the solution of inverse kinematics of robot.Then,under the known working state of the robot(the angle,the angular velocity,the angular acceleration of each joint),combined with the Newton-Euler inverse dynamic formula,the space inertia matrix is parameterized and the complete parameter set corresponding to the linear regression form of the dynamic equation is extracted.The equation is simplified by the least square method and the QR decomposition method of the matrix and the dynamic model with the simplest identifiable parameter set is obtained.This algorithm greatly reduces the time complexity of solving dynamics problems.The calculation speed is about 13 times that of conventional iterative algorithms and the correctness of the model is verified by the Robot Toolbox full scope comparison.Combining the features of redundant dual-arm robots running at low speeds and small inertia lightweight manipulators,the complex dynamics model is simplified.A fast parameter identification method based on "symmetrical trajectories" is designed and implemented.A set of universal the Modeling Toolbox dealing with the dynamic modeling is established and motion control problems of single-arm and dual-arm robots is solved.The force-free control of the robot is realized by means of moment compensation.On the one hand,the dynamic model is tested and at the same time,it serves for dragging and teaching,forming a complete robotguided programming method.A coordinated drag based on force-free control is proposed.In the case of only position constraints and dual constraints of position and force,a dual-arm master-slave coordinated drag control system under a real-time multi-tasking operation architecture is realized.For safety reasons,the robot collision prevention and collision detection modules are designed and realized.Finally,the design of the dual-arm joint synchronous motion experiment and the coordinated posture follow-up experiment of the coordinated conveyance verify the effectiveness of the coordinated drag system from two aspects: the synchronization of the coordinated drag and the accuracy of the following position.Moreover,the general-purpose dynamic modeling toolbox provides a good interface for robot motion control in the future,lowers the threshold of algorithm entry,and improves work efficiency.