摘要:
A method of controlling automatic state returns relates to a dynamic system coupled to an automatic control operating in a discrete negative feedback mode. The method includes a phase for defining a controller, and a phase for operating the system. The defining phase is realized in an open-loop learning phase which includes a step of reading states in which a system may be situated, and a step of generating commands for returning the system to an ideal state. When the commands generating step takes place, the method supplies, for each state, a sequence of discrete commands which are determined by imposing a constraint intended to reduce the error relative to that state below a predetermined threshold.
摘要:
A disk having a servo burst pattern used for generating PES curves for MR heads is disclosed. The disk has a plurality of tracks and each of the tracks has a track width. The servo burst pattern includes a first servo burst and a second servo burst forming a first servo burst pair; and, a third servo burst and a fourth servo burst forming a second servo burst pair. The second servo burst pair is circumferentially adjacent to the first servo burst pair. The third servo burst spans a distance of (TW/2+K(TW/2)), while the fourth servo burst spans a distance of ((TW/2+(2-K)(TW/2)). In the above equations, TW equals the track width and 0
摘要:
A method of estimating the gain of a servo control system including an actuator, in which input data supplied to the actuator and the actuator's position data are applied to a gain estimate formula in a closed loop discrete value system for controlling the actuator, so as to estimate the gain of the servo control system.
摘要:
A positioning adaptive control method and positioning device which allow rapid positioning of a head by speed-controlling a seek operation in an information storage device such as a magnetic disk unit. The seek operation moves the head to a vicinity of a target track and a following operation causes the head to accurately follow a position on the target track when the head is positioned in the vicinity of the target track. These operations are controlled based on data recorded in sectors formed on a recording plane of a disk. A variable gain of an acceleration feed forward signal is controlled sequentially by an adaptive control rule so that a deviation signal between a target speed and an actual speed of the head is reduced when the speed of the head is shifted from an acceleration or constant speed state to a deceleration state under speed control. The variable gain of the acceleration feed forward is used per each sampling for the adaptive control rule and a square value of the speed deviation signal is minimized.
摘要:
In a digital servo control system especially suitable for use in disk drives, a sample integrity tester is provided. Sample measurements, indicating the position of a disk drive's read/write head relative to tracks of information on a recording medium, are subject to error due to noise. The sample integrity tester 2410, 2420, 2430 effectively filters out noise-corrupted measurements and thus prevents clearly erroneous measurements from contaminating calculations performed within the servo controller's control loop. If a measured position signal falls outside a given window (indicating a possible spurious position value has been read), an observer's predicted value is used rather than the spurious value. Using the predicted value allows the loop to operate in a "freewheel" (open-loop) mode. A preferred implementation of the sample integrity tester involves a coarse window that is static, and a fine window that changes dynamically based on an effort signal.
摘要:
A slider for attachment to a flexure of a disc drive system includes a slider body, a transducing head formed on the trailing edge of the slider body, and a microactuator formed on the leading edge of the slider body. The microactuator engages the flexure to rotate the transducing head in response to control signals applied to the microactuator. The slider is applicable to achieve fine positioning of the transducing head in a disc drive having an actuator arm supporting the flexure and a motor operable to move the actuator relative to a disc to coarsely position the transducing head. The microactuator and the transducing head may be formed by thin film deposition.
摘要:
An actuator system for positioning a transducing head on an actuator arm over a selected track of a rotatable disc having a plurality of concentric tracks is disclosed. The actuator arm includes a motor responsive to an actuator signal and a bias signal to move the head with respect to the tracks. The actuator signal is applied to the motor to move the head between tracks on the disc. After the head has been moved between tracks, the bias signal is applied to the motor to center the head over the selected track. A lookup table is provided to store predicted bias values in locations addressable by seek direction, previous seek direction, seek length and head position. The bias signal is applied in response to a selectively accessed predicted bias value.
摘要:
A gimbal for supporting a slider at its leading surface in a disc drive assembly includes a gimbal body, a slider support beam and a slider mounting tab. The slider support beam is carried by the gimbal body and defines a vertical slider alignment feature. The slider mounting tab extends out of plane from the slider support beam and defines a horizontal slider alignment feature. The slider mounting tab is attached to the leading surface of the slider. The design of the slider mounting tab of the present invention is useful for supporting a leading edge microactuator at a leading edge of the slider for micropositioning a transducer over ideal track centers on a disc surface.
摘要:
A head positioning apparatus and method for a disk drive system. During each computing time of a plurality of sequential computing times: (a) a position of a servo head on a disk is computed, (b) an actual position of the servo head in the present computing time is computed, based on the computed position of the servo head and an estimated position of the servo head computed in the preceding computing time, (c) a moving distance of the servo head is computed, based on the actual positions of the servo head computed in the present computing time and in the preceding computing time, (d) an estimated position of the servo head in the present computing time, indicating an estimated position reached by the servo head at the succeeding computing time, is computed from the actual position of the servo head computed in the present computing time to the moving distance of the servo head, (e) a moving velocity of the servo head is computed based on the actual position of the servo head computed in the present computing time and the actual position of the servo head computed in the preceding computing time, (f) a remaining number of tracks up to a target track is computed, based on the actual position of the servo head computed in the present computing time, and (g) an object velocity of the servo head is obtained, based on the remaining number of tracks.
摘要:
A disc drive device where data and servo position information is stored in data segments on concentric tracks on the disc surface. The servo position information indicates the track centerline for each data segment. The offset of the servo position information from an ideal track centerline for each track is measured and stored into memory. The read/write head, which accesses data on the disc tracks, is positioned over the track centerline based on the offset for each data segment.