Design and optimization of solar tracker with U-PRU-PUS parallel mechanism

The solar tracker usually adopts the serial mechanism in application, which is greatly affected by the environment, and its load capacity and stability are limited. In order to address these issues, a new type of solar tracking device with U-PRU-PUS parallel mechanism was proposed. The U-PRU-PUS parallel mechanism was analyzed based on the screw theory, which shows that this mechanism has 2R degree of freedom and is decoupled. The direct and inverse kinematics of the parallel mechanism were derived and its singularity was analyzed based on the Jacobian algebras. Then the workspace of the parallel mechanism was obtained according to the boundary search algorithm. The adaptive genetic algorithm was used to search the optimal structure parameters of the parallel mechanism. The tracking range was improved by 4.6% and the stroke of the driving rod was shortened by 11.2% after optimization. A solar tracker prototype with the optimized parallel mechanism and its control system was built. The limit tracking position at sunrise and sunset was tested, which validated the feasibility of the designed mechanism and its tracking range. Through the solar tracking error tests, the performance of the proposed tracking mechanism can track the sun effectively. (C) 2020 Elsevier Ltd. All rights reserved.