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Linear flux-switching permanent-magnet (LFSPM) motors have been proposed for electromagnetic launch system (EMLS). Benefiting from the permanent magnet (PM) settled on the long double-sided primary and the yokeless secondary, the proposed structure has the advantage of high thrust force density and simple structure compared with the traditional linear permanent-magnet synchronous motor (LPMSM) and linear induction motor (LIM), which makes it more suitable for the EMLS. However, it suffers from the deficiency of relatively high detent force due to the permanent magnets (PMs) settled on the primary, which will also exert an influence on the thrust ripple. Different from the traditional rotary motor, the linear motor also suffers from the end force caused by the end effect. So, a new structure of secondary, which is called symmetric unequally spaced (SUS) secondary in this paper, is proposed to improve the electromagnetic performance from the point of the detent force and thrust ripple for the motor. The thrust ripple and detent force are effectively declined by applying the proposed method without the sacrifice of the average thrust force. The validity of the method is verified by finite element analysis (FEA). A prototype with SUS secondary is manufactured to verify the simulation result.

A new double-sided permanent magnet linear switched reluctance motor (PMLSRM) for the major propulsion of an elevator is proposed and investigated in this paper, in which the armature coils and the permanent magnets (PMs) are all located on its primary. The long double-sided secondary is made of iron only, which makes the structure robust and low-cost. The working principle of the PMLSRM is introduced first and two kinds of the motor with series and parallel magnetic circuits are proposed, investigated and compared. Then, we compare the proposed PMLSRM with the LSRM without PMs assisted on the primary in terms of the electromagnetic characteristics. The result shows that the proposed motor is less likely to be saturated under the same excitation which means it could exhibit higher thrust force among large current density range.

IBSS_Gecko_6 is a bio-inspired legged robot that can climb on smooth vertical surface. In this paper, we design a new footpad which equipped with polyurethane adhesive. Different from pervious study, we directly apply the adhesive in the footpad and investigate optimal attaching and detaching trajectory for wall climbing. The optimal adhesion force demonstrated that the leg can perform strong attaching force and modest detaching force, which can supply a reliable force for wall climbing. The optimal trajectory can apply in the wall climbing robot in future.