Mechanical design of 7-DOF manipulator for water jet cutting

Discussed in this paper are the issues underlying the mechanical design of 7-DOF manipulator. A comprehensive solution for the structural type selecting, and the detail design of the links, the joints and the parts is introduced. First the design requirements including the workspace, manipulability, loading capacity, weight, precision, motor power etc are studied. After the preliminary design and calculation, the parameters of the D-H model are determined. We put forward a method to resolve the dynamic problems by software. It is accomplished by blending the unique capabilities of three engineering CAD packages named PRO/E, ADAMS and ANSYS. The statics problems and the multi-body dynamic problems met during the design process will be easily solved by using the software. The parametric geometric model of the manipulator built with PRO/E was transferred to ADAMS. Uniting ANSYS and ADAMS, we began the stress-strain and modality analysis. At last, the complicated flexible multi-body model of the manipulator was set up, and then given the dynamics simulation results which are important for the further design. The finished manipulator has the compact structure and high manipulability. Based on the experiments, the manipulator steers clear of the obstacle in a certain area included in the workspace.