Motion control apparatus

Claim 1

MOTION CONTROL APPARATUS COMPRISING, IN COMBINATION, AN INPUT TRANSDUCER INCLUDING AN ANGULARLY POSITIONABLE SENSING ELEMENT, THE INPUT TRANSDUCER BEING CONSTRUCTED AND ARRANGED SO AS TO DEVELOP A SIGNAL VOLTAGE CORRESPONDING IN MAGNITUDE TO THE SPACING BETWEEN THE TIP OF THE SENSING ELEMENT AND AN OBJECT, A SOURCE OF REFERENCE VOLTAGE CORRESPONDING IN MAGNITUDE TO A PREDETERMINED SPACING BETWEEN THE TIP OF THE SENSING ELEMENT AND THE OBJECT, MEANS COMPARING THE SIGNAL AND REFERENCE VOLTAGES SO AS TO DEVELOP TWO ERROR VOLTAGES EACH OF OPPOSITE POLARITY AND OF A MAGNITUDE CORRESPONDING TO THE DIFFERENCE BETWEEN THE SIGNAL AND REFERENCE VOLTAGES, A SINE-COSINE POTENTIOMETER, MEANS CORRELATING THE SETTING OF THE POTENTIOMETER WITH THE ORIENTATION OF THE SENSING ELEMENT, THE POTENTIOMETER BEING ENERGIZED BY THE TWO ERROR VOLTAGES SO AS TO PROVIDE TWO SINE-COSINE RELATED COMMAND VOLTAGES, TWO MOTORS OPERATIVE TO MANEUVER THE SENSING ELEMENT ALONG PATHS SUBSTANTIALLY AT RIGHT ANGLES TO EACH OTHER, FEEDBACK MEANS OPERATIVE TO PROVIDE A FEEDBACK VOLTAGE CORRESPONDING TO THE SPEED OF EACH MOTOR, AND SUMMING NETWORKS DISPOSED BETWEEN EACH MOTOR AND THE POTENTIOMETER FOR VECTORIALLY ADDING THE RESPECTIVE COMMAND AND FEEDBACK VOLTAGES SO AS TO PRODUCE A CORRESPONDING SUMMED VOLTAGE, THE TWO MOTORS ALSO EACH BEING OPERATIVELY CONNECTED TO THE POTENTIOMETER AND CONTROLLED BY THE RESPECTIVE SUMMED VOLTAGE SO AS TO CAUSE IN ACCORDANCE THEREWITH THE PREDETERMINED SPACING BETWEEN THE TIP OF THE SENSING ELEMENT AND THE OBJECT TO BE MAINTAINED THROUGHOUT 360* RELATIVE MOTION BETWEEN THE SENSING ELEMENT AND THE OBJECT.