Inverse Displacement Analysis of General 7R Manipulator Based on Hyper-Chaotic Least Square Method

The hyper-chaotic least square method finding all real solutions of nonlinear equations was proposed and the inverse displacement analysis of general 7R manipulator was completed. Applying D-H method, 4 × 4 matrix transform was obtained. Analyzing the characteristic of the matrix, six constrained equations were established and six supplement constrained equations were also established by adding variables. The inverse displacement analysis of general 7R manipulator can be solved by the above 12 equations and the method-finding was given. Combining least square method with hyper-chaotic sequences, hyper-chaotic least square method based on utilizing hyper-chaotic discrete system to obtain locate initial points to find all real solutions of the nonlinear questions was proposed. The numerical example was given for the inverse displacement analysis of general 7R manipulator. The results show that all real solutions have been obtained, and it proves the correctness and validity of the proposed method.