Numerical positioning control system

Claim 1

A CONTROL SYSTEM FOR MOVING ONE OBJECT WITH RESPECT TO ANOTHER OBJECT IN ACCORDANCE WITH A COMMAND SIGNAL COMPRISING: A SOURCE OF INPUT DATA FOR PROVIDING SAID COMMAND SIGNAL, MEANS FOR GENERATING A REFERENCE SIGNAL OF A GIVEN FREQUENCY, MEANS FOR STORING A SIGNAL REPRESENTATIVE OF THE ACTUAL POSITION OF SAID ONE OBJECT IN TERMS OF ITS ABSOLUTE COORDINATE, MEANS FOR COMPARING SAID POSITION AND COMMAND SIGNALS AND GENERATING A FIRST CONTROL SIGNAL WHEN SAID COMMAND SIGNAL REPRESENTS A COORDINATE LARGER THAN THE COORDINATE REPRESENTED BY SAID POSITION SIGNAL, SAID COMPARING MEANS GENERATING A SECOND CONTROL SIGNAL WHEN SAID COMMAND SIGNAL REPRESENTS A COORDINATE SMALLER THAN THE COORDINATE REPRESENTED BY SAID POSITION SIGNAL, MEANS COUPLED TO SAID COMPARING MEANS FOR GENERATING A SECOND SIGNAL OF THE SAME FREQUENCY AND PHASE AS SAID REFERENCE SIGNAL, SAID SECOND SIGNAL GENERATING MEANS BEING RESPONSIVE TO SAID FIRST CONTROL SIGNAL FOR CHANGING THE FREQUENCY OF SAID SECOND SIGNAL TO VALUE ON ONE SIDE OF SAID GIVEN FREQUENCY, SAID SECOND SIGNAL GENERATING BEING RESPONSIVE TO SAID SECOND CONTROL SIGNAL FOR CHANGING THE FREQUENCY TO A VALUE ON THE OTHER SIDE OF SAID GIVEN FREQUENCY, MEANS COUPLED TO SAID COMPARING MEANS AND RESPONSIVE TO SAID FIRST AND SECOND CONTROL SIGNALS FOR CHANGING THE POSITION SIGNALS STORED IN SAID POSITION STORING MEANS SO THAT THEY WILL CONTINUALLY REGISTER THE POSITION OF SAID ONE OBJECT, PHASE CONTROL MEANS RESPONSIVE TO INCREMENTAL CHANGES IN POSITION OF SAID ONE OBJECT FOR CHANGING THE PHASE OF AN APPLIED SIGNAL A PROPORTIONAL AMOUNT, PHASE DISCRIMI-