Nidec Motor Corporation

Cosma Pabouctsidis

Steven C Bartz

Nikolaos Adamopoulos

Christopher J Schur

Dimitrios Papathanasopoulos

A dual encoder system includes first and second encoders on a single printed circuit board mounted on an electric motor. Each encoder independently generates feedback information used by motor and safety controllers for controlling the motor. A single magnet is mounted on the motor shaft. The first encoder cooperates with the magnet to provide first encoder information to the motor controller regarding magnetic alignment between a rotor and a plurality of stator windings of the motor and regarding real-time position and velocity. The second encoder cooperates with the same magnet to provide second encoder information to a safety controller, wherein the second encoder information should be identical to the first. The safety controller may receive the first encoder information from the motor controller, compare the second encoder information to the first encoder information, and brake the electric motor if the second encoder information is different from the first encoder information.

Dual encoder system for electric motor

A safety switching system and method for braking an electric motor in a mobile device. A multi-phase shorting system brakes the motor by diverting power from the motor windings. Multiple independent switching units each include a switch control unit controlling multiple normally-closed switches which, in response to a safety controller, close to connect a respective motor winding to electrical ground. An electromechanical brake system mechanically brakes the motor. An independent switching unit includes two normally-open switches which, in response to the safety controller, opens to activate an electromechanical brake. A feedback system communicates to the safety controller a switch failure of any of the switches either as a short circuit fault or an open circuit fault. The feedback system may include an analog and/or a digital feedback system. If a switch failure is detected, the safety controller may activate the multi-phase shorting system and the electromechanical brake system.

Safety switching system and method for braking electric motor

An apparatus and method arbitrates bidirectional optical communication across optical link ends of independent controller area network buses. A mobile device has a battery management system and a first controller area network bus having a first optical link end, and a charging station has a second controller area network bus having a second optical link end. When the mobile device aligns with the charging station for charging, the optical links ends align to allow communication between the battery management system and the charging station regarding charging the battery. The arbiter apparatus is operationally interposed between the optical link ends and arbitrates the bidirectional communication by delaying a subsequent communication from one of the battery management system and the charging station until a dominant bit of a prior communication is released, thereby preventing the controller area network buses from transmitting simultaneously across the optical link ends.

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Geneva, Switzerland

Cosma Pabouctsidis