Experimental and analytical studies of the sinusoidal dither signal in a DC motor system

Abstract

Abstract. In this article we are concerned with the implementation of a dither signal for a closed-loop DC motor system. Experimental studies show that the system contains two nonlinearities that are saturated with dead zone and backlash. Parameter estimation techniques are used to identify the unknown system parameters with special care due to the existence of system nonlinearities. An analytical method is then presented to deal with the closedloop DC motor system with two nonlinearities in the loop. Self-excited oscillations are found to exist in the system. A good correlation between the theoretical and experimental results indicates the success of the system identification and modelling process. Also the ability of dither to quench the limit cycle is demonstrated from these results.

Nonlinear Dynamics and Control in an Automotive Brake System

“…All dynamic systems have a spectrum of Lyapunov exponents (λ), which can be Liaw and Tung [28] used a dither smoothing technique to control noisy chaotic systems. Tung and Chen [29] presented an approach for identifying a closed-loop DC motor system with unknown parameters and nonlinearities; in addition, they investigated why dither signals eliminate possible limit cycles in the system. Furthermore, Chang et al [30], used dither signals to suppress a chaotic permanent magnet in the synchronous motor of an electric vehicle.…”

“…Because dither is an external signal and does not require measurements, its main advantage is simplicity. Dither has also been successfully applied in actual nonlinear systems [27][28][29][30]. For example, Fuh and Tung [27] used dither signals to convert chaotic motion to a periodic orbit in circuit systems.…”

Dither signals with particular application to the control of windscreen wiper blades

“…This technique is also extensively used in several real nonlinear systems (Feeny and Moon, 2000;Tung and Chen, 1993;Fuh and Tung, 1997;Liaw and Tung, 1998). Tung and Chen (1993) presented an approach for identifying for a closed-loop DC motor system with unknown parameters and nonlinearities. The nature of the dither signal that eliminates possible limit cycles in the system was also investigated.…”

Control Chaos for Permanent Magnet Synchronous Motor Base on Adaptive Backstepping of Error Compensation

“…Permanent magnet synchronous motor (PMSM) have better properties than the conventional internal combustion engine vehicle, such as independence from petroleum, reliability and quiet and so on [7][8][9].…”