Tracking control of optimal quantization feedback control systems with variable discrete quantizer

Networked control systems (NCSs) have been receiving much attention in the field of remote robot operation, surgery and some operations. In the NCSs, data needs to be quantized since it is transmitted over a limited network channel. In earlier works, we considered an NCS with a variable discrete quantizer. In the system, both input and a parameter of the quantizer are optimized online with the help of model predictive control (MPC) so that the system is stabilized. However, the method is not applied to the tracking control, directly. This paper addresses an extension of the quantized feedback control system in order to consider the tracking control performance as well as the stabilization of the system. In the system, the center of the quantization is considered as a variable to be optimized. The optimization problem is reduced to a mixed integer quadratic programming so that the tracking control can be realized online. Experimental results are demonstrated to verify the effectiveness of the proposed method.