Experiment evaluation of reliable control using equivalent transfer function for speed feedback loop failure

In this paper, a reliable control method is proposed for a position control system using multiple loops. If a speed feedback loop fails, such as a case of the speed sensor break down, the position control system becomes unstable and has a big fluctuation. To cope with this problem, the proposed method uses an equivalent transfer function (ETF) as an active redundancy compensation after the loop failure. The ETF is designed so that it does not change the transfer function of the whole system before and after the loop failure. Therefore, the stability of the position control system using this proposed system is guaranteed even if the speed feedback loop fails. The effectiveness of this proposed system is confirmed by the experimental results.