Adaptive digital servo system

Claim 2

An adaptive servo system comprising: a track position profile sequencer for generating a sequence of n define position signals; a track correction profile sequencer for generating a sequence of n correction signals, each of said n correction signals being associated with a corresponding n define position signal generated by said track position profile sequencer; a present position decoder for generating an output signal indicative of the actual present position of the member being moved and controlled by the servo system; an error generator connected to the track position profile sequencer and the present position decoder for generating an error signal indicative of the difference between the one of said n define position signals being generated by said track position profile sequencer and the output signal of the present position decoder for defining the difference between the commanded position as commanded by the track position profile sequencer and the actual position as defined by the present position decoder; track correction profile generator connected to the present error generator for generating an output connected signal indicative of the repeatable error component of the error signal presently being generated by the present error generator; updating means within said track correction profile sequencer connected to said track correction profile generator for updating the correction profile associated with the track presently being followed so as to correct the correction profile to cause the repeatable error component of the error signal to approach a zero value when the corrected correction profile is used by the track correction profile sequencer to generate said sequence of n correction signals.

Claim 3

An adaptive positioning system comprising: a track position profile sequencer comprising: a track position profile memory for storing the position profile for each track of a plurality of tracks, the position profile for each track being stored as a sequence of n position values, and a position signal generator connected to said track position profile memory for sequentially transmitting each of said n position values associated with a presently addressed track; a track correction profile sequencer comprising; a track correction profile memory for storing the correction profile for each of a plurality of said tracks, the correction profile for each track being stored as a sequence of n correction values so that there exists a corresponding correction value for each position value in said track position profile memory; a correction signal generator connected to said track correction profile memory for sequentially transmitting each of said n correction values for the track presently being addressed; updating means connected to said track correction profile memory for modifying the track correction profile of the track presently being addressed as stored within the track correction profile memory; an actual position detector for generatinG an actual position signal indicative of the present position of the member being controlled by said positioning system; an error generator for generating an error signal indicative of the difference between the value of the position signal being transmitted by said track position profile sequencer and the actual position signal being generated by said actual position detector; a track correction profile generator comprising; a storage for storing the last k values of the error signal generated by said error generator; a repeatable error detector connected to said storage for extracting the repeatable error component from the k values of the error signal stored in said storage and for generating an output repeatable error correction signal, said output repeatable error correction signal being connected as an input to said updating means of said track correction profile sequence generator so as to modify the track correction profile to cause the repeatable error component in the error signal generated by said error generator to approach zero.

Claim 4

An adaptive positioning system comprising: a track position profile sequencer comprising: a track position profile memory for storing the position profile for each track of a plurality of tracks, the position profile for each track being stored as a sequence of n position values, and a position signal generator connected to said track position profile memory for sequentially transmitting each of said n position values associated with a presently addressed track; a track correction profile sequencer comprising; a track correction profile memory for storing the correction profile for each of a plurality of said tracks, the correction profile for each track being stored as a sequence of n correction values so that there exists a corresponding correction value for each position value in said track position profile memory; a correction signal generator connected to said track correction profile memory for sequentially transmitting each of said n correction values for the track presently being addressed; updating means connected to said track correction profile memory for modifying the track correction profile of the track presently being addressed as stored within the track correction profile memory; an actual position detector for generatinG an actual position signal indicative of the present position of the member being controlled by said positioning system; an error generator for generating an error signal indicative of the difference between the value of the position signal being transmitted by said track position profile sequencer and the actual position signal being generated by said actual position detector; a track correction profile generator comprising; a storage for storing the last k values of the error signal generated by said error generator; a repeatable error detector connected to said storage for extracting the repeatable error component from the k values of the error signal stored in said storage and for generating an output repeatable error correction signal, said output repeatable error correction signal being connected as an input to said updating means of said track correction profile sequence generator so as to modify the track correction profile to cause the repeatable error component in the error signal generated by said error generator to approach zero.

Claim 5

The adaptive positioning system of claim 2 wherein said updating means employs the repeatable error correction signal to modify only the correction value that was associated with the position signal that was used in conjunction with the actual position signal which generated the last error signal value to be stored in said storage of said track correction profile generator.

Claim 6

An adaptive position system as set forth in claim 2 wherein repeatable error detector generates a repeatable error correction signal for each of the n correction values associated with the track being addressed for each new error signal value generated by said error generator, and said updating means modifying each of said n correction values associated with the track correction profile of the track presently addressed by the associated repeatable error correction signal for each of said n correction values such that each of said n correction values will be updated n times each time the track correction profile is used.

Claim 7

An adaptive position system as set forth in claim 2 further comprising combination means connected to said error generator and said correction signal generator of said track correction profile sequencer for combining the transmitted correction value with the error signal generated by said error generator to form a command signal, said control signal controlling the actuator used to move the member under control of the adaptive position system.

Claim 8

An adaptive servo system as set forth in claim 2 wherein said actual position detector comprises: an actuator; a light source for emitting a light beam; a light detector for detecting the presence of the beam from said light source; a disk rotatably mounted, said disk having a plurality of apertures, each of said apertures being in a triangular form, said apertures being uniformly located on a concentric track on said disk; reflecting means attached to said actuator for reflecting said light onto said concentric track of said disk such that the light beam will impinge the triangular apertures on said concentric track; present position decoder generating a position signal by measuring the time period that said light beam passes through each of said apertures on said disk, said time period representing the actual position of said member.

Claim 9

The adaptive positioning system of claim 6 wherein said disk has n apertures.

Claim 10

An adaptive position system as set forth in claim 3 further comprising combination means connected to said error generator and said correction signal generator of said track correction profile sequencer for combining the transmitted correction value with the error signal generated by said error generator to form a command signal, said control signal controlling the actuator used to move the member under control of the adaptive position system.

Claim 11

An adaptive positiOn system as set forth in claim 4 further comprising combination means connected to said error generator and said correction signal generator of said track correction profile sequencer for combining the transmitted correction value with the error signal generated by said error generator to form a command signal, said control signal controlling the actuator used to move the member under control of the adaptive position system.

Claim 12

An adaptive servo system as set forth in claim 3 wherein said actual position detector comprises: an actuator; a light source for emitting a light beam; a light detector for detecting the presence of the beam from said light source; a disk rotatably mounted, said disk having a plurality of apertures, each of said apertures being in a triangular form, said apertures being uniformly located on a concentric track on said disk; reflecting means attached to said actuator for reflecting said light onto said concentric track of said disk such that the light beam will impinge the triangular apertures on said concentric track; present position decoder generating a position signal by measuring the time period that said light beam passes through each of said apertures on said disk, said time period representing the actual position of said member.

Claim 13

The adaptive positioning system of claim 10 wherein said disk has n apertures.

Claim 14

An adaptive servo system as set forth in claim 4 wherein said actual position detector comprises: an actuator; a light source for emitting a light beam; a light detector for detecting the presence of the beam from said light source; a disk rotatably mounted, said disk having a plurality of apertures, each of said apertures being in a triangular form, said apertures being uniformly located on a concentric track on said disk; reflecting means attached to said actuator for reflecting said light onto said concentric track of said disk such that the light beam will impinge the triangular apertures on said concentric track; present position decoder generating a position signal by measuring the time period that said light beam passes through each of said apertures on said disk, said time period representing the actual position of said member.

Claim 15

The adaptive positioning system of claim 12 wherein said disk has n apertures.

Claim 16

An adaptive servo system as set forth in claim 5 wherein said actual position detector comprises: an actuator; a light source for emitting a light beam; a light detector for detecting the presence of the beam from said light source; a disk rotatably mounted, said disk having a plurality of apertures, each of said apertures being in a triangular form, said apertures being uniformly located on a concentric track on said disk; reflecting means attached to said actuator for reflecting said light onto said concentric track of said disk such that the light beam will impinge the triangular apertures on said concentric track; present position decoder generating a position signal by measuring the time period that said light beam passes through each of said apertures on said disk, said time period representing the actual position of said member.

Claim 17

The adaptive positioning system of claim 14 wherein said disk has n apertures.

Claim 18

An adaptive servo system as set forth in claim 8 wherein said actual position decoder comprises: an actuator; a light source for emitting a light beam; a light detector for detecting the presence of the beam from said light source; a disk rotatably mounted, said disk having a plurality of apertures, each of said apertures being in a triangular form, said apertures being uniformly located on a concentric track on said disk; reflecting means attached to said actuator for reflecting said light onto said concentric track of said disk such that the light beam will impinge the triangular apertures on said concentric track; present position decoder gEnerating a position signal by measuring the time period that said light beam passes through each of said apertures on said disk, said time period representing the actual position of said member.

Claim 19

The adaptive positioning system of claim 16 wherein said disk has n apertures.

Claim 20

An adaptive servo system as set forth in claim 9 wherein said actual position detector comprises: an actuator; a light source for emitting a light beam; a light detector for detecting the presence of the beam from said light source; a disk rotatably mounted, said disk having a plurality of apertures, each of said apertures being in a triangular form, said apertures being uniformly located on a concentric track on said disk; reflecting means attached to said actuator for reflecting said light onto said concentric track of said disk such that the light beam will impinge the triangular apertures on said concentric track; present position decoder generating a position signal by measuring the time period that said light beam passes through each of said apertures on said disk, said time period representing the actual position of said member.

Claim 21

The adaptive positioning system of claim 18 wherein said disk has n apertures.