LAUSR

Backlash and inertia variations, which exist in gear transmission servo systems, often bring inaccuracies, oscillations or even instability. This paper presents an adaptive second-order discrete terminal sliding-mode controller (2-ADTSMC) to deal with the problem. The main contributions of this paper are as follows. First, the characteristic model of gear transmission servo system, which reduces the complexity of traditional mathematics model, is established to describe the load inertia variations. Second, the second-order discrete terminal sliding-mode control is firstly designed based on the characteristic model to restrain the backlash effect. Third, theoretical analysis proves that the quasi-sliding mode is reached in finite steps and the tracking error converges into a bounded set in finite steps. The improvement of tracking performance is verified by simulation and experimental results.