This paper proposes a novel two-axis solar tracker with a redundant parallel mechanism and investigates the distribution method of driving torque. In view of the difference between the singular configuration of the redundant parallel mechanisms and that of the corresponding non-redundant ones, an index related to the minimum singular value of the Jacobian matrix is used to indicate the position of the singular configuration relative to the boundaries of the required workspace. The driving torque and energy consumption can be optimized with this index. Based on the fact that the direction of driving torque is opposite to that of rotor in most of the running processes, a distribution method of driving torque with the minimum energy consumption for the redundant parallel solar tracker is proposed. The distribution method is compared with the minimum norm solution which is adopted by the conventional redundant parallel mechanism. And energy consumption can be significantly reduced by adopting this method. In addition, the workspace and energy consumption of the redundant solar tracker and its non-redundant counterpart are compared. The results show that the redundant solar tracker has a larger workspace and lower energy consumption.
Journal of Mechanisms and Robotics Open Issues