Optimal Kinematic Design of Gantry Parallel Robots

This paper addresses some issues of optimal kinematic design of parallel robot with 3 degrees of freedom. Robot performs translational gantry type motion with a large workspace. The structure’s nominal kinematics is identical to the Linear Delta Robot, the difference being the way which the links are organized. In order to yield a design of the Gantry Parallel Robot with a large workspace volume and good kinematic properties, multi-criteria optimization is used. The objective functions comprise a space utilization index and the inverse conditioning number of the Jacobian matrix. Three different geometrical layouts of the robot are examined and the Pareto optimality between the objective functions is found for several different cases. Pareto-optimal curves showing the relationship between the workspace size and the manipulability are presented as a tool for the designer. The obtained results give a good overview of the kinematic properties of the Gantry Parallel Robot that can be used for designing the parallel structures for various applications.