The application of a parallel manipulator requires kinematic calibration of the base and tool transformation in order to eliminate the errors resulting from manufacturing and assembly of connecting parts. In this paper, a calibration method of base and tool transformation is developed by virtue of optical position sensors. Error model for calibration is constructed and an iterative calibration procedure is introduced. In addition, the pose measurement using a commercial 3D position measurement system, OPTOTRAK 3020, is described. Simulation and experiment results show that the method effectively improves the accuracy of manipulator.

The path planning of legged locomotion is difficult in that not only the body trajectory but also the foot placement need to be considered. A general approach of path planning will fail in generating a feasible path for walking machines when facing the huge searching space of legged locomotion. In this paper, an effective method of path planning for 3D walking is introduced. The basic idea is that a feasible path is generated based on the terrain evaluation which produces an index of terrain complexity with respect to the machine mobility. The terrain evaluation is first carried out in a 2D space by considering the leg placement. The 2D terrain complexity is then modified according to the height's influence on the body motion for the 3D results. As an illustration, a feasible path is generated by applying the potential-guided searching technology to the 3D terrain complexity.

A parallel manipulator can be used for medical operations for its high stiffness and motion accuracy. However, the small and oddly distributed workspace of the general manipulator limits its applications. In this paper, a special manipulator which has a redundant degree of freedom (the 7-DOF) is introduced to improve the workspace. The workspace of the manipulator was analyzed with respect to the selected orientations. Two configurations of the 7-DOF were considered. The preliminary result of the analysis shows that the workspace of the manipulator can be effectively improved with the redundant degree of freedom.