Accurate tracking of coil resistance
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsFernando A. Zayas, Michael Chang
Life of this patent
Estimating the term…
Abstract
Methods and computer program products for determining accurate estimates of coil resistance are provided. Current differences between pairs of current values are determined. Additionally, voltage differences between pairs of actuator coil voltages (corresponding to the current values) are determined. Coil resistance is estimated based on the current differences and the voltage differences. These coil resistance estimates can be useful for accurately estimating actuator coil, actuator arm and/or head velocity.
Claims40
A method for determining accurate estimates of coil resistance associated with an actuator coil of a voice coil motor (VCM), comprising:
- (a) determining a current difference between a pair of current values, wherein each of the current values corresponds to a different current command that is provided to a VCM driver;
- (b) determining a voltage difference between a pair of coil voltages corresponding to the pair of current values;
- and
- (c) estimating coil resistance based on the current difference and the voltage difference.
A method for determining accurate estimates of coil resistance associated with an actuator coil of a voice coil motor (VCM), comprising:
- (a) determining a current difference between a pair of current command values, wherein each of the current command values corresponds to a different current command that is provided to a VCM driver;
- (b) determining a voltage difference between a pair of coil voltages corresponding to the pair of current command values;
- (c) repeating steps (a) and (b) a plurality of times, each time with a different pair of current command values and coil voltages, to thereby determine a plurality of current differences and a corresponding plurality of voltage differences;
- and
- (d) estimating coil resistance based on the plurality of current differences and the plurality of voltage differences.
A method for determining accurate estimates of coil resistance associated with an actuator coil of a voice coil motor (VCM), comprising:
- (a) determining a current difference between a pair of current measurements wherein each of the current measurements corresponds to a different current command that is provided to a VCM driver;
- (b) determining a voltage difference between a pair of coil voltages corresponding to the pair of current measurements;
- (c) repeating steps (a) and (b) a plurality of times, each time with a different pair of current measurements and coil voltages, to thereby determine a plurality of current differences and a corresponding plurality of voltage differences;
- and
- (d) estimating coil resistance based on the plurality of current differences and the plurality of voltage differences.
A method for determining accurate estimates of coil resistance associated with an actuator coil of a voice coil motor (VCM), comprising:
- (a) measuring current through an actuator coil to produce a plurality of current values, wherein each of the current values corresponds to a different current command that is provided to a VCM driver;
- (b) measuring voltage across the actuator coil to produce a plurality of voltage values, wherein each of the voltage values corresponds to one of the current values;
- (c) determining current differences between pairs of current values;
- (d) determining voltage differences between pairs of voltage values;
- and
- (e) estimating coil resistance based on the current differences and the voltage differences.
A method for determining accurate estimates of coil resistance associated with an actuator coil of a voice coil motor (VCM), comprising:
- (a) determining current differences between pairs of current values wherein each of the current values corresponds to a different current command that is provided to a VCM driver;
- (b) determining voltage differences between pairs of coil voltages corresponding to the pairs of current commands;
- and
- (c) estimating coil resistance based on the current differences and the voltage differences.
A method for determining accurate estimates of coil resistance associated with an actuator coil of a voice coil motor (VCM), comprising:
- (a) sampling voltages across an actuator coil and a sense resistor, to produce a plurality of voltage values and corresponding current values, wherein each of the voltage values and its corresponding current value corresponds to a different current command that is provided to a VCM driver, and wherein each sampling occurs just prior to a new current command being provided to the VCM driver;
- (b) determining current differences between pairs of current values;
- (c) determining voltage differences between pairs of voltage values;
- and
- (d) estimating coil resistance based on the current differences and the voltage differences.
A method for determining accurate estimates of coil resistance associated with an actuator coil of a voice coil motor (VCM), comprising:
- (a) sampling voltages across an actuator coil, wherein each of the coil voltage samples corresponds to a different current command that is provided to a VCM driver, and wherein each sampling occurs just prior to a new current commands being provided to a VCM driver, to produce a plurality of coil voltage samples;
- (b) determining current differences between pairs of the current commands;
- (c) determining voltage differences between pairs of the coil voltage samples;
- and
- (d) estimating coil resistance based on the current differences and the voltage differences.
A machine readable medium having instructions stored thereon that when executed by a processor cause a system to:
- determine current differences between pairs of current values, wherein each of the current values corresponds to a different current command that is provided to a VCM driver;
- determine voltage differences between pairs of coil voltages corresponding to the pairs of current values;
- and
- estimate coil resistance associated with an actuator coil of a voice coil motor (VCM) based on the current differences and the voltage differences.
A method for determining accurate estimates of coil resistance associated with an actuator coil of a voice coil motor (VCM), comprising:
- (a) determining current differences between pairs of current measurements corresponding to current commands that are within an acceptable tolerance of estimated bias forces, wherein each of the current values corresponds to a different current command that is provided to a VCM driver;
- (b) determining voltage differences between pairs of coil voltages corresponding to the pairs of current measurements;
- and
- (c) estimating coil resistance based on the current differences and the voltage differences.
A method for determining accurate estimates of coil resistance associated with an actuator coil of a voice coil motor (VCM), comprising:
- (a) determining current differences between pairs of current commands values that are within an acceptable tolerance of estimated bias forces, wherein each of the current command values corresponds to a different current command that is provided to a VCM driver;
- (b) determining voltage differences between pairs of coil voltages corresponding to the pairs of current commands;
- and
- (c) estimating coil resistance based on the current differences and the voltage differences.
Dependencies are inferred from the claim text.