-
公开(公告)号：BR7908521A
公开(公告)日：1980-09-09
申请号：BR7908521
申请日：1979-12-26
Applicant: IBM
Inventor： TAYLOR J , LAISHLEY W
Abstract: A sampled data servo positioning system employs an actuator (50) to move a member between a current and a target position. Incremental position feedback is provided only at sampling times. The system employs a model (60,61, 64) responsive to a velocity related input signal to produce a continually available model incremental position signal. Phase comparing means (70) indicates phase differences between the model and sampled position signals at the sampling times.The system has two operational configurations in the first of which a source of saturation control signals is connected to the actuator to cause maximum acceleration or deceleration thereof. In this first configuration, the model is forced to track the actuator motion by means of feed-forward plus feedback control. The feedforward signal represents actuator performance while the feedback signal is the position signal phase difference. In the second operational configuration, a velocity profile signal is applied to the model and the actuator is forced to track the model by means of feedfoward plus feedback control. The feedback signal is again the position signal phase difference but the feedforward signal is a predetermined signal representing the desired actuator current to execute the velocity profile. The sampled data servo positioning system may be the access motion control system of a sector servo disk file.
-
公开(公告)号：ZA76615B
公开(公告)日：1977-09-28
申请号：ZA76615
申请日：1976-02-03
Applicant: IBM
Inventor： COMANDER R , TAYLOR J
Abstract: A positioning system for data storage apparatus in which a magnetic transducer is positioned relative to data tracks on a moving record member by means of a closed loop servo system. Improved velocity control information is provided to the servo system by pre-recorded servo tracks read by a single servo head forming part of the closed loop system. Each servo track consists of a plurality of servo cells, alternate ones of which are laterally displaced by half a track width. A position reference signal is prerecorded in each cell at a point which is predetermined to permit the signal to be sensed by the single servo head independently of any other detectable signal. Accordingly, a position error signal derived from displaced cells is always 90 DEG out of phase with the position error signal derived from undisplaced cells. During a track access operation, when the servo head is moved from one track to another track, the displaced and undisplaced cells are sensed by the single servo head to provide two separate position error signals. Control circuits combine selected portions of the two position error signals to provide a composite signal of improved linearity from which the velocity of the head during the access operation can be ascertained directly and employed to perform control functions dependent on velocity.
-
公开(公告)号：BR7603098A
公开(公告)日：1977-01-25
申请号：BR7603098
申请日：1976-05-17
Applicant: IBM
Inventor： COMMANDER R , TAYLOR J
Abstract: A positioning system for data storage apparatus in which a magnetic transducer is positioned relative to data tracks on a moving record member by means of a closed loop servo system. Improved velocity control information is provided to the servo system by pre-recorded servo tracks read by a single servo head forming part of the closed loop system. Each servo track consists of a plurality of servo cells, alternate ones of which are laterally displaced by half a track width. A position reference signal is prerecorded in each cell at a point which is predetermined to permit the signal to be sensed by the single servo head independently of any other detectable signal. Accordingly, a position error signal derived from displaced cells is always 90 DEG out of phase with the position error signal derived from undisplaced cells. During a track access operation, when the servo head is moved from one track to another track, the displaced and undisplaced cells are sensed by the single servo head to provide two separate position error signals. Control circuits combine selected portions of the two position error signals to provide a composite signal of improved linearity from which the velocity of the head during the access operation can be ascertained directly and employed to perform control functions dependent on velocity.
-
公开(公告)号：ZA7600615B
公开(公告)日：1977-09-28
申请号：ZA7600615
申请日：1976-02-03
Applicant: IBM
Inventor： COMANDER R , TAYLOR J
CPC classification number: G11B5/5521 , G11B5/59688
-
-
-
Search Results
4
records
(took 0.017 seconds)
