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Programmable Positioning System

IP.com Disclosure Number: IPCOM000049223D
Original Publication Date: 1982-May-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 3 page(s) / 36K

Publishing Venue

IBM

Related People

Martinez, AL: AUTHOR

Abstract

Mechanical error tolerances of positioning systems for massive equipment can be controlled by using a clock by clock feedback servo system. The position of the equipment is checked after each step by the motor until a comparison is made with the required position. The system then steps backward a certain number of pulses to relieve the stress in the gear system and minimize gear backlash. The comparison is again checked, and if correct, the operation is performed. If the position now is incorrect, the motor is again stepped and checked each pulse until a comparison is made, and the procedure continues to perform the reverse motor step and recheck for a number of times.

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Programmable Positioning System

Mechanical error tolerances of positioning systems for massive equipment can be controlled by using a clock by clock feedback servo system. The position of the equipment is checked after each step by the motor until a comparison is made with the required position. The system then steps backward a certain number of pulses to relieve the stress in the gear system and minimize gear backlash. The comparison is again checked, and if correct, the operation is performed. If the position now is incorrect, the motor is again stepped and checked each pulse until a comparison is made, and the procedure continues to perform the reverse motor step and recheck for a number of times. If the system cannot settle into the correct position from this direction, the positioning system is stepped beyond the correct position and the procedure starts the stepping from the reverse direction until a correct comparison is obtained.

As shown in the block diagram, the positioning procedure is started by obtaining the information of the present position of the equipment from a linear transducer and directing this information to a compare circuit. The required position is obtained by accessing the memory store, and this information is also directed to the compare circuit. If a comparison is not made, the motor is stepped one step and the procedure continues around to again compare the required position with the present position of the mechanism. This loop continues until a comparison is made at which time the procedure branches from the "yes" leg of the compare into a delay block. A delay timer is enabled and allowed to time out. After the delay, a programmed number of pulses are directed to the motor to step the motor in the reverse direction to which the mechanism traveled to arrive at that position. This backward motion relieves the stress on the gear systems and minimizes the gear backlash. The procedure continues to increase the count by one and then to che...