Development of A New Cable-driven Planar Parallel Continuum Robot Using Compound Kinematic Calibration Method

This paper presents the design, calibration, and development of a novel cable-driven planar parallel continuum robot (PCR). The PCR employs a novel drive unit, which is mainly composed of cables, guiding pulleys and miniature linear actuators. The kinematic model of the PCR is derived based on the constant curvature assumption and the space vector method, and its workspace and singularity are analyzed. In addition, this paper adopts a novel compound kinematic calibration method, which includes the linear calibration method in the robot-specific model and the use of genetic algorithm (GA) in the robot-independent model. To verify the validity of the calibration method, the pose accuracy is assessed by providing positional points on the elliptical trajectory, and the trajectory tracking accuracy is evaluated by using the circular and rectangular trajectories. The experimental results show that the static positioning accuracy is maintained at 1mm, meanwhile the trajectory tracking accuracy is controlled within the range of 0.9-1.4mm. The PCR developed in this paper shows good comprehensive performance by employing the proposed novel compound kinematic calibration method.