Estimator positioning system and method
AssigneeInternational Business Machines Corporation
InventorsVincent P. Thomas, Peter Baker
Life of this patent
Estimating the term…
Abstract
A system and method for controlling the movement of a member, particularly the heads of a disk file, to a specified position in a predetermined path, makes use of an electromagnetic responsive to control signals and to position reference information and a transducing means for reading such information to produce a position signal. The position signal is sampled regularly and, together with the actuator control signal, used to update a velocity estimator. During the deceleration phase of the movement, a new actuator control signal is generated at each sample time from the square of the estimated velocity divided by the computed distance-to-go to the specified position.
Claims13
A method of controlling the movement of a member in a Positioning system to a specified position in a predetermined path along which the member is movable by an actuator in response to actuator control signals, said movement comprising at least acceleration and deceleration phases, the system further including position reference information and transducing means capable of reading such position reference information to produce a signal indicative of the relative position of the member, the method comprising the steps of
- sampling the signals from the position transducing means at regular sampling times;
- computing the distance-to-go to the specified position;
- estimating the velocity of the member at each sampling time in accordance with a mathematical model of the system and in response to at least the current position signal sample and actuator control signal;
- generating, during said deceleration phase of movement, an actuator control signal based on said velocity estimate and distance to go;
- applying the generated actuator control signal to the actuator and member is within a predetermined distance of the specified position;
- characterized in that the actuator control signal is calculated at each sample time during said deceleration phase of movement as a function of the square of the estimated velocity divided by the distance-to-go.
A positioning system including an actuator (14) for moving a member (13, 17) to a specified position along a predetermined path in response to actuator control signals, the movement comprising at least acceleration and deceleration phases;
- position reference information associated with the path of movement;
- transducing means (17, 19) capable of reading such position reference information and producing signals indicative of the relative position of the member (13, 17);
- sampling means (28, 29) for sampling the relative position indicating signals at regular sampling times;
- means (31) for computing the distance-to-go to the specified position;
- a velocity estimator (30) for estimating the velocity of the member at each sample time on the basis of a mathematical model of the positioning system and in response to at least the current position sample and actuator control signal;
- and
- means (37) for generating, at each sample time during said deceleration phase of movement, an actuator control signal, based on said velocity estimate and distance-to-go;
- and for applying the generated actuator control signal to the actuator, characterized in that:
- the actuator control signal generated by said generating means during said deceleration phase of movement is calculated, at each sample time, as a function of the square of the estimated velocity divided by the distance-to-go.
Dependencies are inferred from the claim text.