Abstract: An optical tactile sensor has a touch pad and a CCD camera for imaging behavior of the touch pad. A CPU processes image information from the CCD camera, extracts information on the size, shape, and center of gravity of a contact region, and extracts information on the size of a fixation region. The CPU obtains a normal force from the size of the contact region, obtains a tangential force from the shape of the contact region and the center of gravity of the contact region, and obtains a friction coefficient from the ratio of the size of the fixation region to the size of the contact region.

Abstract: Disclosed is a magnetic bearing system for use in a vacuum pump including a rotor provided with a rotary blade. The magnetic bearing system comprises a rotary shaft rotationally holding the rotor, a motor for rotationally driving the rotary shaft, a magnetic levitation section for supporting the rotor relative to a stator through the rotary shaft in a non-contact manner, a rotation detection section for detecting a magnetic pole position of the motor, a rotor-temperature detection section for detecting a temperature of the rotor, a carrier-wave generation section for supplying a common carrier wave to each of a plurality of sensors provided in the magnetic levitation section, the rotation detection section and the rotor-temperature detection section, and an A/D conversion section for sampling a sensor signal output from each of the sensors, in synchronization with the carrier wave.