Abstract: A method for monitoring an electric motor employing a pulse-type rotational position sensor includes monitoring a signal output from the pulse-type rotational position sensor and a reference signal associated with a control signal for the electric motor. A position of a rotor of the electric motor coincident with the reference signal is determined based upon a nominal rotor position, a nominal rotational speed of the rotor and a time between the reference signal and a falling edge of the signal output from the pulse-type rotational position sensor. The electric motor is controlled based upon the position of the rotor.

Abstract: A method for monitoring an electric motor employing a pulse-type rotational position sensor includes monitoring a signal output from the pulse-type rotational position sensor and a reference signal associated with a control signal for the electric motor. A position of a rotor of the electric motor coincident with the reference signal is determined based upon a nominal rotor position, a nominal rotational speed of the rotor and a time between the reference signal and a falling edge of the signal output from the pulse-type rotational position sensor. The electric motor is controlled based upon the position of the rotor.

Abstract: A method of determining processor utilization includes: counting, via a first counter on a processor, a number of elapsed clock cycles while code is being executed; counting, via a second counter on a processor, a total number of free-running clock cycles; and dividing the number of clock cycles where code is being executed by the total number of free-running clock cycles to determine a CPU utilization.

Abstract: A motor control processor is provided for motor phase current sampling of multiple variable frequency controlled electric motors, and includes an analog-to-digital (A/D) converter and a controller. The A/D converter has multiple analog inputs and generates a digital output signal in response to the multiple analog inputs. The controller is coupled to the A/D converter and determines a maximum desired switching frequency for a first one of the multiple variable frequency controlled electric motors. The controller further selects a base period in response to the maximum desired switching frequency and defines a phase shift time delay as a fraction of the base period so the controller may control the multiple analog inputs of the A/D converter to sample motor phase currents of each of the multiple variable frequency controlled electric motors at sample times determined by the controller in response to the base period and the phase shift time delay.

Abstract: Methods and apparatus are provided for controlling first and second motors. A controller includes a processor supplying a control signal for driving the motors and a logic circuit coupled to the processor. The processor produces a first trigger coordinated with the rate of the first motor and a second trigger coordinated with the rate of the second motor. The logic circuit produces a third trigger from a combination of the first and second triggers. The processor includes a converter for sampling the currents of the motors in response to the third trigger. The processor further produces a modified pulse width in the first trigger if a period between the first and second triggers is less than a predetermined limit and directs the converter to consecutively sample the currents in response to the modified pulse width.

Abstract: Methods and apparatus are provided for controlling first and second motors. A controller includes a processor supplying a control signal for driving the motors and a logic circuit coupled to the processor. The processor produces a first trigger coordinated with the rate of the first motor and a second trigger coordinated with the rate of the second motor. The logic circuit produces a third trigger from a combination of the first and second triggers. The processor includes a converter for sampling the currents of the motors in response to the third trigger. The processor further produces a modified pulse width in the first trigger if a period between the first and second triggers is less than a predetermined limit and directs the converter to consecutively sample the currents in response to the modified pulse width.

Abstract: A motor control processor is provided for motor phase current sampling of multiple variable frequency controlled electric motors. The motor control processor comprises an analog-to-digital (A/D) converter and a controller. The A/D converter has multiple analog inputs and generates a digital output signal in response to the multiple analog inputs. The controller is coupled to the A/D converter and determines a maximum desired switching frequency for a first one of the multiple variable frequency controlled electric motors. The controller further selects a base period in response to the maximum desired switching frequency and defines a phase shift time delay as a fraction of the base period so that the controller may control the multiple analog inputs of the A/D converter to sample motor phase currents of each of the multiple variable frequency controlled electric motors at sample times determined by the controller in response to the base period and the phase shift time delay.