Method and apparatus for time-optimized positioning of at least one body in a desired target position

Apparatus for time-optimizing positioning of a body at a target position (3) having a motor (130) driving the body with predetermined torque from a start position (2, 12) to the target positions (3) comprising

• means (10) storing an identification of the target position (3);
• means (134, 135) providing identification of an actual position of the body;
• means (113) comparing the actual and target position and providing a distance-to-target signal;
• means (119, 120, 122) furnishing a motor speed signal;
• quadrant identification means (124) responsive to the distance-to-target signal and the motor speed signal to determine, in a Cartesian coordinate system, the direction and distance of movement of the motor;
• speed-distance relation memory means (PROM, 115) storing a curve representative of the loci on a speed-distance curve at which the motor must reverse torque, while the body is being moved to the target and requiring only a single torque reversal;
• means (117, 126) coupled to the speed-distance relation memory means (115) and the motor speed furnishing means (119, 120, 122) and providing an output signal coupled to the quadrant region identification means (124) when, upon operation of the motor, the position of the body intersects the speed-distance curve stored in said speed distance relation memory means (115), said quadrant region identification means then providing a torque-reversal command signal;
• motor control means (132, 133) responsive to the distance-to-target signal as well as to the torque reversal command signal and controlling the motor to provide output torque first in the direction required to bring the body to the target and then, upon receiving the torque reversal command signal, to reverse the motor torque to brake approach of the body to the target;
• means (144) defining a target accuracy range (.DELTA.s.sub.o) and representative of the maximum tolerance distance of positioning of the body from the target position, and furnishing a tolerance range signal;
• means (145) defining a target speed approach range (.DELTA.v.sub.o) representative of maximum deviation of speed of the body when its movement is controlled by the motor from a commanded speed and furnishing an approach range signal;
• and means (146, 122) connected to and responsive to the tolerance range signal and the approach range signal additionally controlling the motor control means to deenergize the motor when the body is within the target accuracy range and moving at the approach range speed.