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In this study, an adaptive fuzzy‐based mixed H2/H∞ tracking control design is developed in robotic systems under unknown or uncertain plant parameters and external disturbances. The mixed H2/H∞ control design has the advantage of both H2 optimal control performance and H∞ robust control performance and the fuzzy adaptive control scheme is used to compensate for the plant uncertainties. By virtue of the skew‐symmetric property in the robotic systems and adequate choice of state variable transformation, sufficient conditions are developed for the adaptive fuzzy‐based mixed H2/H∞ tracking control problems in terms of a pair of coupled algebraic equations instead of a pair of coupled differential equations. The proposed methods are simple and the coupled algebraic equations can be solved analytically. Simulation results indicate that the desired performance of the proposed adaptive fuzzy‐based mixed H2/H∞ tracking control schemes for the uncertain robotic systems can be achieved.

In this paper, an adaptive control scheme is proposed for the permanent magnet synchronous motor (PMSM) with uncertain parameters using an LMI approach. The adaptive control scheme is used to compensate some uncertain terms in the PMSM drive system. In this study, a novel formulation for the uncertain PMSM drive system is developed. By the formulation, the stability condition for the closed-loop uncertain PMSM drive system with the proposed controllers can be characterized in terms of somne linear matrix inequalities (LMIs). The LMIs problem (LMIP) can be efficiently solved. Numerical solutions for the control gains and simulation results are provided to illustrate the design procedure and the performances. In opposition to try and error, the control gains in both speed loop and current loop can be obtained systematically by solving the corresponding LMIs. The proposed method is simple and is suitable for practical control design in motor drive.

This paper presents a novel speed sensorless adaptive control scheme for the uncertain permanent‐magnet synchronous motor (PMSM) drive system using a linear matrix equalities approach with a digital signal processing (DSP) chip. The dynamic model of the PMSM drive with eight error states based on the structure of speed estimator, speed and current controllers is developed. The speed controller, current controller and rotor speed and position estimators are considered simultaneously and designed together. In addition, a three‐parameter observer is also designed and the adaptive control law is derived in the light of Lyapunov stability theorem. The objective of this study is to determine the two estimation gains and the six control gains such that the closed‐loop system is stable. The stability condition of the system can be characterized in terms of some linear matrix inequalities (LMIs). The LMIs problem can be efficiently solved with the help of MATLAB simulation tool. Differently from the conventional proportional‐integral controller, a novel controller with a low‐pass filter instead of a pure integrator is proposed. By a suitable adjustment for a design parameter, the steady‐state error can also be improved. Numerical solutions of the controller and the estimator gains and simulation examples are provided to illustrate the design procedure and corresponding performances. The experimental results by using a TI TMS320F28335 DSP chip with the speed reference 400, 700, 1000 RPM, respectively and sudden change of the reference demonstrate the performance of the proposed control scheme.