Kinematics Analysis Of Hybrid Machining Robot Used For Drilling Aircraft Wing Beam

Aiming at drilling large parts,such as aircraft wing beam which is extremely large and has strict processing requirements this paper puts forward further improvement measures for the existing automated flexible machining units.For the first time this paper puts forward the integrated mobile hybrid machining robot for drilling aircraft wing beam.The integrated mobile hybrid machining robot has two working modes which includes machining mode and walking mode.In machining mode the robot can be seemed as parallel robot which can solve the problem of low precision,the lack of strength and rigidity.Further the robot can reconfigure to be a hybrid robot in walking mode and with help of the mechanism reconstruction and the locking pin to achieve fast and stable walking.That method provides a new solution for the large parts processing.In this paper two working states of the integrated mobile hybrid machining robot are analyzed in detail and the kinematics parameters modeling and solving analysis of the machining state are carried out.By using the method of coordinate transformation which is widely used to solve the inverse kinematics problem.The robot's forward kinematics configuration is solved by a numerical method which based on Jacobian matrix.This method is fast and is less influenced by the initial value selection and more practical.Through the case analysis the correctness of the inverse kinematics and the forward kinematics is verified.The size and shape of robot workspace is an important indicator of the kinematic performance.In this paper a simulation method based on geometric method and Matlab/Sim Mechanics software is proposed.The principle of simulation method based on geometric method and Matlab/Sim Mechanics software is used to build a robot model.By adding drive module,control module and sensor module in the model the robots' instantaneous position of the execution module can be tracked and captured.Then the robot workspace can be drawn out according to the geometric method.And the simulation method based on geometric method and Matlab/Sim Mechanics software is fast and simple for solving engineering problems.Based on the global performance index theory the approximate calculation method of the mean value of the Jacobian/Hessian matrix condition number in the whole workspace is proposed.With the help of large sample sampling points the theoretical exact solution of the performance index is fully approximated.According to the build way of series robots' Jacobian matrix and Hessian matrix the robot's Jacobian matrix and Hessian matrix in machining mode are built in this paper.Further the two theories of global performance index and global performance fluctuation index are synthesized.Based on the above method the kinematic global performance index and the global performance fluctuation index of the robot can be solved.Then the range of the scale parameter of the mechanism with excellent global kinematic performance and small fluctuation can be determined.Simulation results of the kinematic parameters of the robot show that the motion of the robot is more stable and the control precision is higher which proves the rationality and validity of the proposed method.Aiming at the walking stage of the integrated mobile hybrid machining robot,the gait planning,planning of the branch end trajectory and solution of the joint angle are carried out.The MATLAB software is used for numerical simulation.The structure of the robot is built by using MATLAB/Sim Mechanics toolbox,and the walking mode is simulated numerically.The results of the simulation method show the feasibility of the walking scheme and provide important theoretical reference for the follow-up research and improvement.