Texas Instruments Corporation

Sameer Pradeep Kulkarni

Prasad Kulkarni

Ganapathi Hegde

Venkata Pavan Mahankali

Krushal Shah

A motor controller that is operable to control a motor includes drive current generation circuitry having an output coupled to the motor. The motor controller further includes a velocity control path. The velocity control path includes angular velocity estimation circuitry having an input adapted to be coupled to the motor, a velocity comparator having first input coupled to a target velocity input and a second input coupled to an output of the angular velocity estimation circuitry, and an adaptive velocity controller having a first input coupled to an output of the velocity comparator and having an output coupled to a first input of the drive current generation circuitry. The motor controller further includes controller parameter determination circuitry having a first input coupled to the output of the angular velocity estimation circuitry and having an output coupled to a second input of the adaptive velocity controller.

Motor controller and a method for controlling a motor

A method for determining a position of a rotor of a brushless direct current (BLDC) motor at standstill. The method includes providing a plurality of current pulses to a plurality of windings of the BLDC motor while the rotor of the BLDC motor is at a standstill position. The method further includes measuring a plurality of times that it takes for the plurality of current pulses to reach a threshold for respective ones of the plurality of windings. A first position corresponding to a shortest time of the plurality of times is determined. A position detection value is determined based on the shortest time and based on times corresponding to positions that are adjacent to the first position. A position of the rotor at the standstill position is determined based on the position detection value and an interpolation function.

Method for determining a position of a rotor at standstill

Example systems and processes use three-phase vector mutual inductance analysis to detect zero-crossing (ZC) locations of back-electromotive force (BEMF) of an electric motor and to detect its commutation points during start-up or low-speed operation. For each sector of rotation of the rotor, two pairs of three-phase vectors are applied, along with current for the corresponding driving phase. The first pair is alternately applied to move the rotor, and the mutual inductances resulting from such application are compared to detect the zero-crossing (ZC) location in the BEMF of the electric motor in that sector. The second pair is then alternately applied within the same sector to continue to move the rotor, and the mutual inductances from such application are compared to detect the commutation point of the electric motor in that sector. The process may be repeated for each successive sector, changing the driving current at each new sector.

Inductance-based, high-torque start up of electric motor

In some examples, an apparatus operable to drive a motor includes driver circuitry adapted to be coupled to the motor and processing logic coupled to the driver circuitry. The processing logic is operable to determine an expected current for controlling the motor, reduce a reference current upon which the motor is controlled from a first value to a second value at an exponential rate, determine that a measured current of the motor is approximately equal to the expected current, and responsive to determining that the measured current of the motor is approximately equal to the expected current, provide a control signal to the driver circuitry based on the expected current to the motor to control the motor to operate according to closed loop control.

Brushless motor control

A controller is adapted to be coupled to a brushless direct current (DC) motor and includes an analog-to-digital converter (ADC), a computing device, and a driver. The ADC is configured to receive an analog back electromotive force (BEMF) waveform from the brushless DC motor and sample the analog BEMF waveform to produce a digital BEMF waveform. The computing device is coupled to the ADC and is configured to receive the digital BEMF waveform and determine a position and a speed of the rotor based on the digital BEMF waveform. The driver is coupled to the ADC and the computing device and is configured to receive the position and the speed of the rotor and provide a drive signal based on the position and the speed of the rotor of the brushless DC motor.

Growing community of inventors

Bengaluru, India

Sameer Pradeep Kulkarni