Explicit Model Predictive Control In Motor Control

Explicit model predictive control (EMPC) addresses the problem of removing one of themain drawbacks of model predictive control (MPC), namely, its on-line high complexcomputations. EMPC changes all the computations necessary for the implementation of MPCinto off-line form, while it preserves all the other characteristics, getting the regions of explicitcontroller and their corresponding optimal control law. It makes the on-line computationsreduce into simple function evaluations, which saves considerable time. It has largely extendedthe range of MPC applications.In this paper, EMPC is used in Motor control. Firstly, from theoretical perspective, asimulation is conducted on Simulink in order to examine the control algorithm designed for athree-phase induction motor model and a brushless DC motor model using EMPC. The resultproves the applicability of EMPC in high-speed sampling systems. Secondly, EMPC is appliedin the control of a brushless DC motors (BLDCM) for real-time control based on the DSPplatform. It shows that EMPC used in actual object is also feasible.This paper is organized as follows:1. The research status, the development and the basic principle of EMPC are introduced.Among these, the off-line/on-line theoretical derivations of EMPC are addressed. Inaddition, solving problems of EMPC for different situations are also discussed in thissession.2. Mathematical model of the three-phase induction motor is built. The model is casted intoPWA framework after it is approximated by PWA functions and it is tested by a Simulinkexperiment. The result proves the feasibility of EMPC in high-speed sampling systems.3. First, the non-linear model of brushless DC motor is built and casted into a PWA formatusing PWA functions, which is easy for the handling of EMPC. Then EMPC is used in thismodel. The simulink results show that the torque of the DC motor can be stabilized by the EMPC controller, and the performance is satisfactory.4. The speed-loop model for brushless DC motor control is built with knowing the basicprinciple of brushless DC motor. Then, based on DSP development platform, EMPC is usedto control the speed of BLDCM in real-time situation. The experiment proves theperformance of EMPC is favorable.5. Summary of this paper is given, and the research outlook is pointed out.