Motor controller with drive-signal conditioning

A motor controller, comprising:

• a motor driver configured to generate a digital motor-coil drive signal having a first component at a first frequency;
• and
• a signal conditioner coupled to the motor driver and configured to digitally alter the first component at approximately the first frequency;
• wherein:
• the signal conditioner is configured to generate a conditioning signal;
• and
• the motor driver comprises:
• signal generator configured to generate an initial drive signal;
• a combiner configured to generate an intermediate drive signal from the initial drive signal and the conditioning signal;
• and
• a converter configured to convert the intermediate drive signal into width-modulated pulses that form the motor-coil drive signal.

A motor controller, comprising:

• a motor driver configured to generate a digital motor-coil drive signal having a first component at a first frequency;
• and
• a signal conditioner coupled to the motor driver and configured to digitally alter the first component;
• wherein:
• the motor-coil drive signal has a fundamental component at a fundamental frequency;
• and
• the signal conditioner comprises:
• a first signal generator configured to generate a substantially constant first component of a conditioning signal;
• a second signal generator configured to generate a second component of the conditioning signal having a second frequency, a difference between the first and second frequencies substantially equaling the fundamental frequency;
• and
• a combiner operable to generate the conditioning signal from the first and second components of the conditioning signal and to provide the conditioning signal to the motor driver.

A system, comprising:

• a motor having a coil;
• and
• a motor controller, comprising:
• a motor driver configured to generate a digital drive signal having a first component at a first frequency and to drive the motor coil with the digital drive signal;
• and
• a signal conditioner coupled to the motor driver and configured to digitally alter the first component;
• wherein:
• the motor has a cogging torque at a second frequency;
• and
• the motor controller is configured to generate the drive signal having a fundamental component at a fundamental frequency such that a difference between the first and second frequencies is substantially equal to the fundamental frequency.

A method, comprising:

• driving a coil of a motor with a current;
• determining a frequency component of the current at a first frequency;
• and
• conditioning the current at approximately the first frequency to maintain a magnitude of a vibration experienced by the motor below a threshold in response to the determining of the frequency component;
• the method further comprising:
• generating with the coil a back-electromotive-force voltage having a component at a second frequency;
• wherein the vibration has a component at the first frequency;
• and
• wherein conditioning the current comprises causing the current to have a component at a third frequency such that a difference between the second and third frequencies substantially equals the first frequency.

A method, comprising:

• driving a coil of a motor with a current;
• determining a frequency component of the current at a first frequency;
• and
• conditioning the current at approximately the first frequency to maintain a magnitude of a vibration experienced by the motor below a threshold in response to the determining of the frequency component;
• the method further comprising:
• generating with the coil a back-electromotive-force voltage having a component at a second frequency;
• wherein the vibration has a component at the first frequency;
• and
• wherein conditioning the current comprises causing the current to have a component at a third frequency such that a sum of the second and third frequencies substantially equals the first frequency.