Mode changes of redundantly actuated asymmetric parallel mechanism

A novel parallel mechanism which enlarges the workspace by singularity-free mode changes is proposed. The proposed mechanism has inherited the design of Linear DELTA, three translational degree-of-freedom and the moving plate driven by three linear actuators. In addition, the mechanism is extended by redundant actuation by four linear actuators and asymmetric design. New criterions about redundancy and singularity of redundantly actuated parallel mechanism using summation and product of determinants of minor matrices of the transposed Jacobian matrix are proposed. Redundant actuation and asymmetric design enables singularity-free mode changes with loss redundancy but maintains non-singularity, which is evaluated by the proposed criterions. Numerical simulations demonstrate the singularity-free mode changes of the proposed mechanism.