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In this paper, a new rotary-linear switched-reluctance motor with a magnetic decoupled structure is introduced. The rotational motion of the motor, managed by a sliding-mode controller, is coordinated with the proportional-derivation linear motion by using a fuzzy logic block. Consequently, both rotational and linear motions can be realized simultaneously. In addition, the decoupled magnetic paths of the motor in two directions are analyzed by finite-element method, with the force and torque measurements suggesting the feasibility of the motor. Both the simulation and experimental results show that the motor is totally decoupled in the linear and rotary directions. The linear movement and the rotation at the same time validate the effectiveness of the motor design and the proposed control method, with highly accurate responses for the two degrees of freedom movement. [ABSTRACT FROM AUTHOR]

This paper discusses the tracking coordination of a linear switched reluctance machine (LSRM) network based on a global feedback control strategy with a full-state observation framework. The observer is allocated on the follower instead of the leader to form a leader--follower--observer network, by utilizing the leader as the global feedback tracking controller and the observer as the observation of the full states. The internal model compensator (IMC) is applied to the leader for the improvement of the network performance. The full-state information of the LSRM network is reconfigured by the output of the LSRM where the observer is located to provide necessary feedback information to the leader. Then, the controllability and observability of the leader--follower--observer network with the IMC are inspected, serving as a basis for the design of the global controller with the IMC and full-state observer. Experimentation verifies the effectiveness of the proposed network control scheme and the results demonstrate that both the absolute and the relative accuracy can be simultaneously improved, compared to the LSRM network with only the consensus algorithm and no global feedback mechanism. [ABSTRACT FROM AUTHOR]

This paper proposes a coordinated positioning control network for three direct drive, linear switched reluctance machines. To obtain the optimized network control parameters, the distributed linear quadratic regulator is applied. Different communication topologies are studied for both the dynamic tracking and the coordination performance of the network. Experimental results demonstrate that an absolute static tracking precision of 20~\mu \textm can be achieved from the “cycle” communication topology and an absolute static coordination precision of 11~\mu \textm can be obtained from the “path” communication topology. [ABSTRACT FROM AUTHOR]

A fuzzy position controller is employed for the linear switched reluctance motor. Performance comparison between the fuzzy controller and a proportional-differential (PD) controller is carried out. Under the PD controller, the absolute steady-state error is 44.5 ~211.5 μm under normal condition and 1157–1212 μm under sustained time-variant disturbance circumstance, respectively. The absolute steady-state error of 3 μm and 9 μm can be achieved under the fuzzy controller in the normal and sustained disturbed circumstance. Experimental results demonstrate that the position tracking performance from the proposed algorithm is superior to the conventional PD control strategy, both in normal circumstance and disturbance environment. [ABSTRACT FROM AUTHOR]

In this paper, to enhance the machine performance and realize a high-precision position control performance, a dual-loop position controller is employed for the asymmetric bilateral linear hybrid switched reluctance motor (ABLHSRM). Machine characteristics are investigated by finite-element method. The dual-loop controller is constructed by employing a tradition proportional–integral differential velocity controller as the inner loop and a fuzzy proportional differential (PD) controller for the outer loop. Experimental results demonstrate that both the position control performance and the velocity control performance under the dual-loop control algorithm are superior to the single-loop PD position control strategy. An absolute steady-state error of 4 \mu \textm can be achieved under the dual-loop control strategy. Performance comparison from the ABLHSRM and its asymmetric bilateral linear switched reluctance counterpart with the same dimensions are carried out. Position tracking results show that the rise time is improved for the proposed ABLHSRM under the proposed control scheme. [ABSTRACT FROM AUTHOR]

This paper discusses about the voltage output ripple reduction and error minimization for the direct-drive, linear switched reluctance generator (LSRG)-based wave power generation system. First, the concept of the LSRG-based wave power generation system is studied. According to the characteristics of the LSRG, the suitable drive circuit dedicated to proper current excitation and generation is established. Second, the reasons that cause voltage output ripples are investigated. To reduce the remarkable ripples from phase current commutations, a current distribution function (CDF) is proposed based on the minimized copper loss principle. Third, the dual-loop control strategy with current and voltage as the inner and outer loop is constructed, implemented with the proposed CDF. Theoretical bases of the control strategy are derived. The simulation results prove that the proposed control algorithm is capable of voltage ripple suppression and error reduction within the range of ±0.5 V over the entire operation speed for wave energy extraction, validated by experimental verification. [ABSTRACT FROM AUTHOR]

Core loss is one of the key factors for performance evaluation of switched reluctance machines. In this paper, core loss analysis of the planar switched reluctance motor (PSRM) is calculated based on the 3-D time-stepping finite element methods. The numerical analysis for the computation of the core loss is discussed, also its transient and average core loss in the mover and the stator are calculated. The corresponding experiments of measurement loss for a PSRM prototype are conducted and the results validate the accuracy from the numerical analysis. It can be concluded that core loss dominates around the corner of the mover and stator cores. [ABSTRACT FROM AUTHOR]

An integrated rotary–linear machine based on switched reluctance principle is investigated. The characteristics of the motor are analyzed by finite-element methods, with particular emphasis on the coupled magnetic paths. Results from numerical calculation are verified by the hardware experiment. The simple yet effective decoupling algorithm for the independent position control of both rotary and linear axes is proposed. Implemented with the proportional–integral-differential algorithm, the motor is capable of high-precision rotary and linear position tracking with the steady error within 0.3^\circ and 10~\mum, respectively. [ABSTRACT FROM AUTHOR]

A novel double-sided electric asymmetric linear switched reluctance motor (LSRM) is proposed in this paper. The features of the proposed linear machine are that mover teeth and stators are not exactly identical according to the axis of the moving platform. This machine structure ensures that the alleviation of motor saturation magnetization effect and a higher thrust force output can be derived from the asymmetric LSRM. A thorough magnetic analysis is carried out for performance prediction of the machine, and results are compared to a symmetric LSRM counterpart. Both theoretical and finite-element methods results prove the priority of the asymmetric LSRM with higher force-to-volume ratio and better acceleration performance. Experimental results from the machine prototype validate the design of an asymmetric LSRM with yoke length of 12 mm. [ABSTRACT FROM PUBLISHER]

A transverse-flux tubular linear machine with novel gear-shaped teeth for high force density is proposed. The teeth can be formed by silicon steel laminations or permanent magnets for a tubular linear switched reluctance or tubular linear hybrid motor. With the unique improved teeth structure and short magnetic circulation paths, larger propulsion force output can be obtained with reduced mover weight and volume. Simulation based on finite element method (FEM) verifies the validity of the proposed machine design. The proposed machines are compared with other transverse-flux linear machines. Results show that the proposed tubular motors exhibit better output performance with a higher force-to-volume ratio. [ABSTRACT FROM AUTHOR]

An improved force distribution function (FDF) of linear switched reluctance motors (LSRMs) based on nonlinear inductance modeling for force ripple minimization and smooth speed operation is proposed. Nonlinear inductance profile is divided into three segments with a K factor that depicts current effect on inductance of the LSRM. Speed controller based on the proposed FDF and the nonlinear inductance model is constructed. Both simulation and experimental results verify the proposed FDF with the nonlinear inductance modeling effectively reduce force ripples with uniform speed response. [ABSTRACT FROM AUTHOR]

In planar switched reluctance motors (PSRMs), the electromagnetic force ripple minimization is important to reduce the noise and vibration for high-precision motions. In this paper, an improved PSRM by optimization design for minimization of the electromagnetic force ripple is proposed. The structure, principle, and mathematical model of the PSRM are clarified. Based on Ansoft Maxwell, optimization design of the PSRM is performed by improved structure with smaller pole pitch and incremental number of mover poles. Experiments of the improved PSRM are implemented based on dSPACE. The experimental results verify that the improved PSRM effectively reduces electromagnetic force ripple with planar trajectory tracking. [ABSTRACT FROM AUTHOR]