Abstract:
A system for controlling a motor may include a motor driver circuit for driving a camera motor. A memory capable of storing a plurality of parameters for controlling the camera motor may also be included. A set of parameters from the memory may be chosen to be applied to driving the motor. A motor control module may receive a signal from the control logic module, apply the chosen set of parameters to driving the camera motor, and command the motor driver circuit to drive the motor in accordance with the applied set of parameters. The parameters may be chosen based on desired behavior of the system and various other stimuli.
Abstract:
A method and apparatus for automatic resonance detection is disclosed for a motor- driven mechanical system such as a voice coil motor (VCM) in which a resonance detector and driver are provided. The automatic resonance detector may be implemented on the same integrated circuit as the driver, and dynamically determines the natural resonant frequency of the VCM driven by the driver. The resonant frequency is determined by measuring the back electromotive force (BEMF) of the VCM, detecting the slope of the BEMF signal, and determining the resonant frequency from the slope of the BEMF signal.
Abstract:
A system for controlling a motor may include a motor driver circuit for driving a camera motor. A memory capable of storing a plurality of parameters for controlling the camera motor may also be included. A set of parameters from the memory may be chosen to be applied to driving the motor. A motor control module may receive a signal from the control logic module, apply the chosen set of parameters to driving the camera motor, and command the motor driver circuit to drive the motor in accordance with the applied set of parameters. The parameters may be chosen based on desired behavior of the system and various other stimuli.
Abstract:
A method and apparatus for automatic resonance detection is disclosed for a motor- driven mechanical system such as a voice coil motor (VCM) in which a resonance detector and driver are provided. The automatic resonance detector may be implemented on the same integrated circuit as the driver, and dynamically determines the natural resonant frequency of the VCM driven by the driver. The resonant frequency is determined by measuring the back electromotive force (BEMF) of the VCM, detecting the slope of the BEMF signal, and determining the resonant frequency from the slope of the BEMF signal.
Abstract:
A method includes driving (302) a component (102, 152) in an electromagnetic actuator (200) back and forth during one or more cycles of the actuator, where the actuator includes a voice coil (106, 156). The method also includes identifying (304) a back electromotive force (EMF) voltage of the voice coil during at least one of the one or more cycles. The method further includes determining (308) whether a stroke of the component is substantially centered using the back EMF voltage of the voice coil. In addition, the method includes, based on the determination, adjusting (310) one or more drive signals for the voice coil during one or more additional cycles of the actuator. Determining whether the stroke of the component is centered could include determining whether the back EMF voltage of the voice coil is substantially maximized or determining whether times between extremes in the back EMF voltage are substantially equal.