Low-voltage dielectric elastomer actuators propel an autonomous untethered subgram robust soft legged robot along complex paths.

This paper presents a very-high-speed (VHS) slotless permanent-magnet motor design procedure using an analytical model. The model is used to design the optimal prototype (target: 200 kr/min, 2 kW). The multiphysics analytical model allows a quick optimization process. The presented model includes the magnetic fields, the mechanical stresses in the rotor, the electromagnetic power losses, the windage power losses, and the power losses in the bearings. VHS machines need a new torque measurement method. This paper presents the developed method. It also presents a ball bearing friction torque measurement method designed particularly for VHS machines. Remarkably, the method allowed us to design a prototype which operates beyond the target of speed and power. The results given by the model are compared with the measurements of the prototype.

In some applications, contacts between two devices are the first cause of dysfunctions. The aim of this paper is to transfer contactless power energy to add new functions to a tool (e.g., drill machine). A bidirectional communication is also needed. This is realized with an ironless high-frequency transformer for both power and information transmission. Different coil geometries have been studied to reduce mutual inductance between power and information coils. This new solution enables to build low-cost and smart energy transfer systems including communication.

This paper presents a general analytical model for predicting the magnetic field of slotless permanent-magnet machines. The model takes into account the effect of eddy currents in conductive regions and notably in conductive permanent magnets without neglecting their remanent field. The modeling of this effect is important for the design of very high speed slotless permanent-magnet machines, as the power losses are linked with the frequency of the field. The model takes into account any number of layers. It implies that, for one, the fields can easily be calculated in a design including a permanent magnet and a conductive retaining sleeve. The model is applicable both to internal rotor and external rotor permanent-magnet machines. The effect of the relative permeability and of the conductivity of the permanent magnet or of the yoke on the magnetic fields is also taken into account. Any magnetization can be taken into account, in particular a Halbach type permanent magnet, or a radially magnetized permanent magnet can be considered.

In many applications, it can be useful transferring energy from a power supply to the load without any physical link. Such a solution can avoid corrosion, waterproofness problems on the one hand. And can help simplifying mechanical design on the other hand. Furthermore, it increases security level making the plugging of the cable useless, especially for high voltage transmission. This can been achieved with an inductive coupler power transfer (ICPT). In most applications, the transformer is loaded by a linear resistance. Thus, in order to recharge batteries, a converter is usually placed at the secondary side to manage battery load profile (a first step at constant current and a second one at constant voltage). The paper discusses a new method allowing the generation of this profile from the primary side. In order to achieve this goal, two compensation topologies are used.