System for positioning movable members with absolute dimension with selectable offset point

Claim 3

The system of claim 1 wherein said first means alternately determines the numerical position offset signal for each axis, and means for alternately applying the actual position signals and the offset position signals for each axis thereto.

Claim 4

The system of claim 1, further including means for determining the magnitude of the position error of each member, and moving each member at a velocity which is a function of its position error.

Claim 5

The system of claim 1 wherein said first and second means are enabled to derive said differences periodically for each axis.

Claim 6

The system of claim 1 wherein said numerical signals indicative of said actual positions are applied to said first means as absolute numbers and said numerical signals indicative of said offset positions are applied thereto as negative numbers.

Claim 7

The system of claim 1 further including means for moving said members as a function of the magnitude of said position errors.

Claim 8

The system of claim 1 further including digital-to-analog converters for each axis adapted to connect said command position signals to analog voltages, a DC motor for moving each of said members, and means for driving said DC motors at speeds proportional to said analog voltages.

Claim 9

A drive system for moving a member at varying speed to a commanded position, comprising a driving member, means drivingly coupling said member to said driving member, means for determining the position error between the commanded position of the member and the actual position thereof and representing said error in digital form, a two-speed gearbox having clutches energizable to determine a high speed and a low speed, a DC motor for driving said driving member through said gearbox, control means for controlling the speed of said DC motor in response to the magnitude of a control signal applied thereto, a digital-to-analog converter, said converter being constructed and arranged to convert first and second predetermined weights of the error in digital form to an analog control signal, means for determining the magnitude of the position error, first means responsive to a predetermined magnitude of the position error for deenergizing said high speed clutch and energizing said low speed clutch, and second means responsive to said predetermined position error for shifting the weight of the digital number applied to said converter.

Claim 10

A drive system for moving a member at varying speed to a commanded position, comprising a driving member, means drivingly coupling said member to said driving member, means for determining the position error between the commanded position of the member and the actual position thereof and representing said error in digital form, a two-speed gearbox having clutches energizable to determine a high speed and a low speed, a DC motor for driving said driving member through said gearbox, control means for controlling the speed of said DC motor in response to the magnitude of a control signal applied thereto, a digital-to-analog converter, said converter being constructed and arranged to convert first and second predetermined weights of the error in digital form to an analog control signal, means for determining the magnitude of the position error, first means responsive to a predetermined magnitude of the position error for deenergizing said high speed clutch and energizing said low speed clutch, and second means responsive to said predetermined position error for shifting the weight of the digital number applied to said converter.

Claim 11

The system of claim 8 further including another motor for driving said driving member at a fixed rapid speed when said position error is above a second predetermined value greater than said predetermined magnitude.

Claim 12

The system of claim 8 further including means for applying a constant level speed control signal to said moTor controller to drive said motor at a fixed fast speed when said position error is above a second predetermined value greater than said predetermined magnitude.