Abstract: Methods and apparatus for motor control having low noise variable-high frequency signal injection for an electric motor. Different injection signals have different signal characteristics. One of the first and second injection signals is selected on a cycle-by-cycle basis as part of a direct voltage signal input to control an electric motor. The first and second signal characteristics are configured to reduce acoustic noise generated by an electric motor.

Abstract: Methods and apparatus for motor control having low noise variable-high frequency signal injection for an electric motor. Different injection signals have different signal characteristics. One of the first and second injection signals is selected on a cycle-by-cycle basis as part of a direct voltage signal input to control an electric motor. The first and second signal characteristics are configured to reduce acoustic noise generated by an electric motor.

Abstract: A method comprising: receiving a first current measurement that is taken at a first predetermined time instant; receiving a second current measurement that is taken at a second predetermined time instant; classifying the first current measurement as corresponding to one of a plurality of electrical signals, the first current measurement being classified based, at least in part, on a duty cycle pattern of the plurality of electrical signals; classifying the second current measurement as corresponding to another one of the plurality of electrical signals, the second current measurement being classified based, at least in part, on the duty cycle pattern of the plurality of electrical signals; and adjusting a duty cycle of at least one of the electrical signals based on the first current measurement, the classification of the first current measurement, the second current measurement, and the classification of the second current measurement.

Abstract: A motor control system for controlling operation of a motor having a plurality of windings includes a gate driver to provide a control signal to one or more switching elements controlling a voltage applied to the plurality of windings and a Field Oriented Control (FOC) controller configured to generate a PWM signal for coupling to the gate driver, wherein the FOC controller comprises a d-axis control loop configured to generate an applied d-axis voltage and a q-axis control loop configured to generate an applied q-axis voltage. A stall detector is configured to calculate an estimate of the q-axis voltage and compare the applied q-axis voltage to a threshold based on the estimate in order to detect a stall condition of the motor.

Abstract: A motor control system for controlling operation of a motor having a plurality of windings includes a gate driver to provide a control signal to one or more switching elements controlling a voltage applied to the plurality of windings and a Field Oriented Control (FOC) controller configured to generate a PWM signal for coupling to the gate driver, wherein the FOC controller comprises a d-axis control loop configured to generate an applied d-axis voltage and a q-axis control loop configured to generate an applied q-axis voltage. A stall detector is configured to calculate an estimate of the q-axis voltage and compare the applied q-axis voltage to a threshold based on the estimate in order to detect a stall condition of the motor.

Abstract: A system for controlling a motor includes a motor having a plurality of phases, each phase comprising a coil having a first end coupled to a motor neutral point. A motor driver circuit is coupled to a second end of each coil to provide power to each coil. A motor controller circuit is coupled to the motor driver circuit to control the power that is provided to the motor. A comparator is coupled to compare a voltage at the motor neutral point to a voltage at the second end of each coil to detect a back-EMF polarity and produce a polarity signal representing the back-EMF polarity. A back-EMF filter circuit is coupled to receive the polarity signal and invert the polarity signal if the polarity signal does not match an expected value.

Abstract: A system is provided for driving a load such as a multi-phase motor. The system includes a motor driver that has a plurality of switches coupled to a motor to drive a current through each of a plurality of phase coils of the motor. A polarity detection circuit detects a polarity of the current in one or more of the phase coils of the motor to generate a polarity value that represents the detected current polarity. The polarity detection circuit can include at least one comparator that has a first input coupled to a node between two of the plurality of switches, a second input coupled to receive a threshold value, and an output from which the polarity value is provided. Further included is a controller that is configured to provide a plurality of pulse width modulated (PWM) output control signals to the plurality of switches to control the switches to drive the current through the plurality of phase coils of the motor.

Abstract: A system is provided for driving a load such as a multi-phase motor. The system includes a motor driver that has a plurality of switches coupled to a motor to drive a current through each of a plurality of phase coils of the motor. A polarity detection circuit detects a polarity of the current in one or more of the phase coils of the motor to generate a polarity value that represents the detected current polarity. The polarity detection circuit can include at least one comparator that has a first input coupled to a node between two of the plurality of switches, a second input coupled to receive a threshold value, and an output from which the polarity value is provided. Further included is a controller that is configured to provide a plurality of pulse width modulated (PWM) output control signals to the plurality of switches to control the switches to drive the current through the plurality of phase coils of the motor.

Abstract: Systems and methods for computing an average supply current to a motor include a current sensor that is configured to sense a current through the motor. A converter is configured to sample the output of the current sensor at times that are established by a trigger signal and convert the samples into digital current values. A trigger signal generator generates the trigger signal based on one or more pulse width modulated (PWM) motor control signals within a PWM cycle. An average supply current value that indicates the average supply current to the motor is computed by a controller using the digital current values received from the converter.

Abstract: A system for controlling a motor includes a motor having a plurality of phases, each phase comprising a coil having a first end coupled to a motor neutral point. A motor driver circuit is coupled to a second end of each coil to provide power to each coil. A motor controller circuit is coupled to the motor driver circuit to control the power that is provided to the motor. A comparator is coupled to compare a voltage at the motor neutral point to a voltage at the second end of each coil to detect a back-EMF polarity and produce a polarity signal representing the back-EMF polarity. A back-EMF filter circuit is coupled to receive the polarity signal and invert the polarity signal if the polarity signal does not match an expected value.

Abstract: A system includes a motor circuit and a calibration test circuit configured to be coupled to the motor circuit to calculate a nominal motor constant representing operation of a motor in a nominal mode, calculate a motor impedance function comprising one or more motor impedance values at one or more motor frequencies, store one or more values of the impedance function in a memory of the motor circuit, and calculate a range of acceptable motor constant values based on the nominal motor constant. The motor circuit may be configured to calculate an operating motor constant value for the motor while operating, wherein the operating motor constant value is based on at least one of the stored values of the impedance function and compare the motor constant value to the range of acceptable motor constant values stored in the memory to detect if a motor stall has occurred.