Finite control set mode predictive control (FCS-MPC) is an emerging technique for control of power electronic converters. This paper introduces a simple and efficient predictive torque control (PTC) algorithm for induction motor (IM) drive. The proposed technique eliminates the need for flux weighting factor for the conventional PTC. As a result, tedious offline tuning is no longer required. At the same time, the proposed technique ensures that the relative importance between torque and flux ripples are determined in an online fashion. Moreover, unlike the conventional method which needs to evaluate the cost function seven times (for two level three-phase inverter case), the proposed method needs only to test four voltage vectors (VVs) at each control sample which leads to a significant reduction in the computation time and switching frequency without sacrificing the performance. The effectiveness of the proposed method is demonstrated by both simulation and experimental results with comprehensive comparisons with the reported literature.

Asymmetrical six-phase (A6P) induction motor-based drives can be considered as a well-established employed technology in high-power safety-critical industry sectors. Of the different control techniques proposed for multiphase machines, model predictive control (MPC) has recently been favored thanks to its simplicity, rapid dynamic response, and flexibility to define new control objectives. One of the main operating challenges when employing MPC to A6P induction machine is the poor quality of the phase current waveform due to the relatively low impedance of the secondary xy subspace. Although different controller structures have been introduced in the available literature to mitigate this problem, most of the available proposals, if not affecting the dc-link voltage utilization, will likely add to the control complexity. From the stator winding layout perspective, this paper attempts to investigate the effect of different winding configurations of six-phase stators with isolated neutral arrangements on the performance of predictive current control (PCC). This study shows that the winding configuration affect the mapping of the 64 available voltage vectors to the αβ and xy subspaces, the induced current ripples, and the required weighting factor employed in PCC. The theoretical findings have experimentally been validated using a 1kW twelve-phase machine that can externally be reconnected to form any of the three available six-phase winding configurations.

Despite the intensive research work on the application of model predictive control for multiphase machines, there are many challenges still to be handled such as high circulating currents, variable switching frequency, and high computation burden. This article proposes a simple, yet efficient predictive current control (PCC) for a six-phase induction motor that reduces considerably circulating current, computation cost, and switching frequency. In the proposed method, a group of four candidate voltage vectors (VVs) is formed in each control sample. Unlike similar methods reported in the literature, these candidate vectors are generated based on a simple lookup table and the previous optimal VV. The lookup table is designed such that it allows only one commutation in each control sample. The performance of the proposed method is assessed experimentally using a 1-kW asymmetrical six-phase induction motor. Different performance indices are investigated to compare the proposed method against two different PCC methods in literature at different operating conditions. The experimental results confirm that about a 50% reduction in average switching frequency and 15% in current total harmonic distortion at different speed ranges are observed with the proposed method compared to the conventional one.

The task of accurate teleoperation of a large workspace industrial manipulator using a small haptic device having a physically limited workspace still a challenge. This task should be handled carefully without disturbing the user perception of continuously teleoperating the manipulator movement in a natural and precise way. This paper presents the development of a master/slave teleoperation system based on a new workspace spanning technique that integrate position control and a modified rate control methods to solve the problem of workspace mapping of two kinematically dissimilar robots. The proposed technique referred to as Positioning with Modified Rate Control is simple yet efficient and overcomes most of the drawbacks of other techniques. It depends on switching between rate control with constant speed for coarse motion and position control for accurate movements. The developed system consists of a phantom premium haptic device as a master and RV-2AJ Mitsubishi robot arm as a slave. Experimental results demonstrate that the operator can easily navigate through the whole workspace of an industrial robot using a small haptic device while achieving accurate positioning. The developed system proved experimentally to have good tracing characteristics in the fine manipulation mode. Besides, a 6 DOF force/torque sensor is attached to the end effector and tested for contact with different stiffness materials.