AN ANALYTICAL INVERSE KINEMATICS SOLUTION WITH THE AVOIDANCE OF JOINT LIMITS, SINGULARITY AND THE SIMULATION OF 7-DOF ANTHROPOMORPHIC MANIPULATORS

A novel analytical method for solving the inverse kinematics of seven-degrees-of-freedom manipulators is presented in this paper. The method avoidsjoint limits and singularities by involving the arm angle (p) to parametrize elbow redundancy. In addition, this method does not need to calculate the complicated parameter 0R30. After discretizing the workspace of the robotic arm, it becomes possible to intuitively observe how the manipulability is distributed throughout its workspace. The relations between the arm angle and thejoint angles are derived. The feasible intervals for the arm angles can be determined for the specified end posture. Finally, to compare the novel method with existing methods, we tested the proposed algorithm on Windows 10 and Ubuntu 18.04. Simulation statistics indicate that when implemented in C++, the proposed algorithm has significant advantages in both convergence time and stability compared to MATLAB; the algorithm achieves an average computing time of 70.12 |us with a standard deviation of 8.45 |us. Besides, we also conducted a comparative analysis with KDL and IKFast, revealing that the proposed algorithm consistently achieves a computing time of 28.54 |us with a standard deviation of 5.45 |us. This finding can provide a theoretical basis for further research on manipulators.