Networked DC Motor Control with Time-Varying Delays and Application to a Mobile Robot

Abstract

Networked dc motors have been extensively studied by researchers. However, issues such as network induced delays, data dropouts, quantization occur in network communication. These issues would generally degrade the closed-loop control system performance by inducing excessive overshoots and fluctuations, and even destabilize the system. In this paper, we focus on the investigation of the impact of network induced delays on a dc motor system, which is controlled via a 4G cellular network. First, we present the plant model of the dc motor and time-varying model for the network induced delay. Next, a full state feedback controller designed via the pole placement method is presented for the dc motor system. Then, the stability criterion by using linear matrix inequalities (LMIs) is employed to evaluate the stability of the networked dc motor closed-loop system subject to the network induced time-varying delay. Numerical simulations and experiments on a real networked dc motor platform are performed to demonstrate the effectiveness of the stability criterion and compare the performance of the dc motor position control with time-varying delays. Moreover, the networked dc motor control system is applied to a two-wheel differential-drive mobile robot and the experimental results show that it can achieve a straight-line path following under the 4G cellular network.