Abstract: A system for the control of a member for following a moving object, especially a small object being part of larger entity, comprising an ultrasonic transmitter and receiver is characterized in that each sensor unit is fixed to the means of movement of a follower member. The ultrasonic sensor units are inexpensive and relatively insensitive to the dirt prevalent in an industrial or an agricultural environment. Since the sensor units can be brought relatively close to the object to be followed, the influence of the distracting larger entity is reduced and an accurate control system is obtained using simple reflection-sensing of the object. The control system can be applied in a milking apparatus. Furthermore the invention provides a method for the automatic milking of an animal.