Distributed LIM-based actuator and control for an ultrafast material transfer network

A concept of distributed actuators and their controls for ultra-fast, material transfer network based upon linear induction motors (LIMs) is presented in this paper. The distributed actuator consists of modularized stationary primaries connected to form a distributed, closed guideway structure with multiple loops through which vehicles (moving secondaries of the LIM) are propelled at a maximum velocity of 120 km/hr and a maximum acceleration of 4 g. The turning radius can be less than 1 m. A transverse flux LIM propulsion unit design provides robust, direct-drive electromagnetic vector controlled propulsion and electromagnetic steering. The controlled moving secondary vehicles are completely passive with no power, sensing, or control intelligence onboard. The need to control multiple passive vehicles simultaneously moving through a multitude of propulsion units mandates a highly distributed control architecture where propulsion units cooperate using a communication network. The need for centralized database and control is eliminated by endowing the communication network with a topology identical to that of the guideway network. The distributed control architecture ensures spontaneity of material delivery by integrating vehicle motion control with intelligence for real-time collision avoidance, a parallel shortest-path routing algorithm, and an autonomous dispatching protocol. Recent experimental results are presented.