A solar tracking drive system can significantly improve the efficiency of photovoltaic panels for receiving solar energy. Compared with series-type, parallel-type solar tracking drive systems have great application potential in solar tacking with its high tracking accuracy, low power consumption and material loss. However, related research is still at the beginning stage and can not meet the actual demand. Therefore, based on 3-RPS parallel mechanism, a novel three-extensible-rod solar tracking drive system for photovoltaic panels was proposed. Three extensible rods had the same structure and were arranged as an equilateral triangle. The upper end of each extensible rod was connected to the photoltaic panel by a compound hinge, and the lower end was connected to the base platform by a rotary hinge. The photovoltaic panel could be driven by changing the lengths of three extensible rods, and then the real-time solar tracking could be realized. Firstly, based on the law of solar motion and the characteristics of 3-RPS parallel mechanism, the related mathematical models of sun tracking were established by the knowledge of space geometry. On the basis of this, for given tracking location, date and mechanism dimensions, the system was analyzed by simulation on the summer solstice and winter solstice, respectively. For the problem that the section number of each extensible rod is too much, a new control strategy of the highly movable centroid of the mobile platform was proposed. For the problem that the rotation range of the commercial spherical hinge is insufficient, a structural scheme of the compound hinge with hook and rotation hinge to replace the spherical hinge was adopted. Moreover, the rotation angle of the compound hinge around each axis was obtained. Then, as the process of tracking the sun is slow, the instantaneous static model of the system was established, and the driving force and driving power of the system were obtained. The maximum driving force is 164.65 N, and the total driving power is 2.94×10-3W. Finally, solar tracking experiments of the system were carried out. The experimental results verified the theoretical and simulation analysis, and the tracking precision of the system is no more than ±0.4°.
