A novel magnetic-attraction positioning actuator

A positioning actuator based on the principles of magnetic attraction and elastic repulsion is presented. The principle of operation of the actuator is simple and resembles that of a caterpillar. Three electromagnets are arranged in line and placed on a ferromagnetic surface. When energized, the two outer electromagnets, E1 and E2, adhere to the surface, anchoring the assembly. The central electromagnet, E2, affixed to E1 and called a motion electromagnet, attracts, when energized, a yoke affixed to E3, overcoming the resilience of an elastic link that joints E2 and the yoke in such a manner that the gap between them can be completely closed. To stop the assembly, either both the outer electromagnets (open-gap standstill) or all three electromagnets (closed-gap standstill) are energized simultaneously. In both cases, the assembly holds on to the ferromagnetic surface. Functional models of a one degree-of-freedom and three degree-of-freedom motion actuators have been built and investigated experimentally