Method and apparatus for positioning a read/write head of a hard disk drive
AssigneeTexas Instruments Incorporated
InventorsMARK W. HEATON, MICHAEL K. MASTEN
Life of this patent
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Abstract
a hard disk drive system (10) includes a rotating magnetic disk (16), and a support arm (22) which is supported for movement relative to the disk under control of a voice coil motor (21). a microactuator (26) supports a read/write head (27) on the support arm for movement relative thereto. a control arrangement (13) controls the voice coil motor and the microactuator in response to position information (31), which is read by the read/write head from the disk and which indicates the position of the read/write head relative to the disk. The system is free of a sensor for detecting the actual position of the support arm relative to the read/write head or the disk.
Claims20
a control apparatus for controlling a system which includes a first part, a movable member, a first actuator supporting a second part on the member for movement relative to the member, and a second actuator operative to effect movement of the member, the first and second actuators each effecting relative movement of the first and second parts, wherein said control apparatus comprises:
- a first control portion having an input which receives an input signal that specifies a target position of the second part relative to the first part, said first control portion being operative to output a first actuator control signal for causing the first actuator to move the second part toward the target position with respect to the first part;
- and
- a second control portion having an input coupled to the first actuator control signal, said second control portion being operative to output a second actuator control signal to cause the second actuator to move the member in a manner so that the second part moves toward the target position with respect to the first part;
- wherein said apparatus is free of a sensor for sensing a position of said member.
a disk drive apparatus, comprising:
- a disk supported for rotation about an axis, and having thereon a magnetic surface;
- a member supported for movement relative to said disk;
- an actuator which is operative to effect movement of said member;
- a microactuator provided on said member;
- a read/write head supported by said microactuator for movement relative to said member, wherein movement of said member by said actuator corresponds to movement of said read/write head adjacent to and in a direction approximately radially of said surface of said disk, and wherein movement of said read/write head by said microactuator corresponds to movement of said read/write head adjacent to and in a direction approximately radially of said surface of said disk;
- a position detecting arrangement operative to generate a position signal representative of a position of said read/write head relative to said disk, said apparatus being free of an arrangement for sensing an actual position of said member;
- and
- a control system responsive to the position signal, and responsive to an input signal specifying a target position of said read/write head relative to said disk, said control system being operative to control said actuator and said microactuator so as to position said read/write head at the target position with respect to said disk.
a method for controlling a system which includes a first part, a movable member, a first actuator supporting a second part on the member for movement relative to the member, and a second actuator operative to effect movement of the member, the first and second actuators each effecting relative movement of the first and second parts, comprising the steps of:
- receiving an input signal that specifies a target position of the second part relative to the first part;
- generating a first actuator control signal as a function of the input signal and without sensing an actual position of the member, the first actuator control signal causing the first actuator to move the second part toward the target position with respect to the first part;
- and
- generating a second actuator control signal as a function of the first actuator control signal and without sensing an actual position of the member, the second actuator control signal causing the second actuator to move the member in a manner so that the second part moves toward the target position with respect to the first part.
Dependencies are inferred from the claim text.