A servo system includes a motor having a stator and a movable element which moves relative to the stator, an encoder which detects at least one of a position and a speed of the movable element of the motor, and a controller including first circuitry which controls operation of the motor based on a detection result of the encoder. The first circuitry of the controller transmits a first command signal that changes a communication speed between the encoder and the controller from a first speed to a second speed which is higher than the first speed, and the encoder includes second circuitry which changes the communication speed between the encoder and the controller to the second speed when the first command signal is received from the controller.

An automatic pet feeder, comprising a bowl with a plurality of compartments, a cover and a sensor, the bowl being rotated relative to the cover to sequentially expose each the compartments, the bowl having location regions detectable by the sensor, each location region having a first edge and a second edge, the motor being driven at a first speed until the first edge is detected, and the motor being driven at a second, slower speed until the second edge is detected, stopping the motor.

A metrology system is provided for use with a movement system that moves an end tool. The metrology system includes a sensor configuration, a light beam source configuration and a processing portion. The light beam source configuration directs a first pattern of light beams and a second pattern of light beams to light beam sensors to indicate a position and orientation of the light beam source configuration. The first pattern of light beams has a lower density of light beams as compared to the second pattern of light beams. Measurement signals from the light beam sensors are processed to determine a position and orientation of the light beam source configuration. The first pattern light beams and the second pattern light beams have at least one different characteristic (e.g., wavelength, polarity, timing, etc.) that enables the first pattern light beams to be distinguished from the second pattern light beams.

The invention at hand relates to a tape measure for determining the position of an elevator car (42) in an elevator shaft (41), the tape measure being disposable vertically in the elevator shaft and preferably so as to extend across at least two floors (43a, 43b, 43c, 43d), the tape measure having a tape-shaped base body (1) and optical coding (2). The tape-shaped base body (1) is made of a textile material and in that the optical coding (2) is inserted in the base body or is applied on a surface (1a) of the base body.

[Problem] To provide a displacement detection apparatus that offers high measurement accuracy while maintaining high versatility.

[Solution] A second birefringent unit 121 and a third birefringent unit 123 are configured to change the phase difference between the first light beam L1 and the second light beam L2 in response to movement of the target T in the measurement direction.