This paper proposes a novel filter, which is based on the event-triggered schedule and the cubature Kalman filter (CKF), to perform the nonlinear remote state estimation in the wireless sensor network with communication constraints. For the purpose of relieving the communication burden between sensors and the remote filter, the event-triggered schedule is utilized to determine whether the current observations should be sent. To deal with the non-Gaussian property due to the nonlinear transformation, the third-degree spherical-radial cubature rule is adopted to provide the accurate estimation. Moreover, the stochastic stability of the designed event-triggered CKF (ETCKF) is analyzed deriving the relationships among the estimation performance, the communication rate and the design parameter. Therefore, the proposed ETCKF can effectively balance the communication burden and the estimation accuracy. Finally, the numerical simulation on IEEE-39 bus system and unmanned aerial vehicles remote attitude monitoring system are performed to verify the practicability of ETCKF.

The cogging force is a main component of the detent force in the permanent magnet linear synchronous motor (PMLSM). It will lead to the thrust ripple and deteriorate the control characteristics, which cannot be neglected especially in precision machine tools. In order to minimize the cogging force, a novel double-sided PMLSM structure with reversed slots is proposed and compared with a conventional PMLSM in this paper. Two novel windings are further added to compensate the unbalanced back electromotive force (EMF) caused by the reversed slots. With this suggested structure, an 8-pole 9-slot double-sided PMLSM is designed. And its detent force and back EMF are evaluated with the help of the 2-D finite element analysis. Finally, a prototype of the double-sided PMLSM with reversed slots is developed, and experiments are carried out to verify the analytical and simulated results.

Continuum robots with their inherent compliance provide the potential for crossing narrow unstructured workspace and safely grasping various objects. However, the display gripper increases the size of the robots, and therefore, it tends to get stuck in constrained environments. This paper proposes a versatile continuum grasping robot (CGR) with a concealable gripper. The CGR can capture large objects with respect to the robot’s scale using the continuum manipulator and can grasp various objects using the end concealable gripper especially in narrow and unstructured workspaces. To perform the cooperative operation of the concealable gripper and the continuum manipulator, a global kinematic model based on screw theory and a motion planning approach referred to as “multi-node synergy method” for the CGR are presented. The simulation and experimental results show that objects of different shapes and sizes can be captured by the same CGR even in complex and narrow environments. Finally, in the future, the CGR is expected to serve for satellite capture in harsh space environments such as high vacuum, strong radiation, and extreme temperatures.

In this paper, the detent force caused by the end effect in a flux-switching permanent magnet linear motor (FSPMLM) with 6 slots and 5 poles is investigated and reduced by two different methods. Firstly, the detent force is diminished by adjusting the position of end teeth of primary side and injecting compensation current into compensation windings wound around the end teeth. Based on the linear relationship between compensation current and compensation force, the proper compensation current is derived and analyzed. Then, to avoid the magnetic coupling between compensation windings and phase windings, a novel compensation module with independent magnet circuit is presented and attached to the primary side of FSPMLM. Thirdly, the two detent force reduction methods are compared with each other, and the compensation module is proved to be more effective. Finally, a prototype of FSPMLM with compensation modules is manufactured and tested to validate the proposed compensation method.

Rehabilitation robots can reproduce the rehabilitation movements of therapists by designed rehabilitation robot control methods to achieve the goal of training the patients’ motion abilities. This paper proposes an impedance sliding-mode control method based on stiffness-scheduled law for the rehabilitation robot, which can be applied to rehabilitation training with both active and passive modes. A free-model-based sliding-mode control strategy is developed to avoid model dependence and reduce the system uncertainty caused by limb shaking. Additionally, the stiffness scheduling rule automatically regulates the impedance parameter of the rehabilitation robot based on the force exerted by the patient on the robot such that the rehabilitation training caters to the patient’s health condition. The proposed method is compared with the fixed stiffness and variable stiffness impedance methods, and the superiority of the proposed method is proved. Rehabilitation training experiments on an actual rehabilitation robot are provided to demonstrate the feasibility and stability of the proposed method.