Abstract: A method for determining the position of a rotor in a permanent magnet synchronous motor includes applying voltage pulses to the windings at successive electrical angles while the motor is at a standstill. The resultant current is sampled. The position of a maximum current is determined by identifying an segment of an electrical cycles which includes the maximum current, and using a spline interpolation to model the current flow in this segment. The maximum current is then correlated to the position of the rotor.

Abstract: A method for determining the position of a rotor in a permanent magnet synchronous motor includes applying voltage pulses to the windings at successive electrical angles while the motor is at a standstill. The resultant current is sampled. The position of a maximum current is determined by identifying an segment of an electrical cycles which includes the maximum current, and using a spline interpolation to model the current flow in this segment. The maximum current is then correlated to the position of the rotor.

Abstract: An electronic line shaft comprising a motor drive comprising a velocity noise filter coupled to receive a feedback position signal and operable to filter the feedback position signal to generate a feedback velocity signal where the noise filter has at least one controllable filter parameter that affects filter operating characteristics and a processing unit operable to execute a wizard for configuring the motor drive, the wizard being operable to receive mechanical characteristic data associated with the motor drive that is provided as input by a wizard user via a user interface and to determine a noise parameter based on the mechanical characteristic data, wherein the at least one controllable filter parameter is adjusted as a function of the noise parameter.

Abstract: A method and apparatus for estimating a system inertia and a load torque in a motor controller, the method comprising the steps of providing an acceleration command signal, determining a motor position, using the motor position to generate an acceleration feedback signal, mathematically combining the acceleration feedback signal and a load torque signal to generate a system inertia estimate, mathematically combining the system inertia estimate and the acceleration command signal to generate a motor torque signal, mathematically combining the system inertia estimate and the acceleration feedback signal to generate an inertia torque and mathematically combining the inertia torque and the motor torque signal to generate the load torque estimate.

Abstract: A method and apparatus for estimating inertia wherein a load has a limited range of load travel, the method comprising the steps of identifying an intermediate position along the range of load travel that is separated from a first end of the range of load travel, with the load separated from a first end of the range of load travel, increasing a velocity of the electric motor from a first velocity, identifying when the load has reached the intermediate position, identifying the motor velocity at the intermediate position as a second velocity, detecting a first rate of velocity change from the first velocity to the second velocity and deriving an inertia value as a function of the first rate of velocity change.

Abstract: An electronic line shaft comprising a motor drive comprising a velocity noise filter coupled to receive a feedback position signal and operable to filter the feedback position signal to generate a feedback velocity signal where the noise filter has at least one controllable filter parameter that affects filter operating characteristics and a processing unit operable to execute a wizard for configuring the motor drive, the wizard being operable to receive mechanical characteristic data associated with the motor drive that is provided as input by a wizard user via a user interface and to determine a noise parameter based on the mechanical characteristic data, wherein the at least one controllable filter parameter is adjusted as a function of the noise parameter.

Abstract: An electronic line shaft includes a motor drive and a processing unit operable to execute a wizard for configuring the motor drive. The wizard is operable to receive mechanical characteristic data associated with the motor drive, determine a noise parameter based on the mechanical characteristic data, and determine at least one control parameter of the motor drive based on the noise parameter.

Abstract: A method and apparatus for estimating a system inertia and a load torque in a motor controller, the method comprising the steps of providing an acceleration command signal, determining a motor position, using the motor position to generate an acceleration feedback signal, mathematically combining the acceleration feedback signal and a load torque signal to generate a system inertia estimate, mathematically combining the system inertia estimate and the acceleration command signal to generate a motor torque signal, mathematically combining the system inertia estimate and the acceleration feedback signal to generate an inertia torque and mathematically combining the inertia torque and the motor torque signal to generate the load torque estimate.

Abstract: An apparatus for use with an encoder feedback device includes a comparator, a counter, and a prediction unit. The encoder feedback device is coupled to rotate with a rotating load and operable to generate at least one feedback position signal indicative of movement of the rotating load. The comparator is operable to receive the feedback position signal and generate a first position signal including a plurality of edges based on the feedback position signal. The counter is operable to receive the first position signal and count the edges to periodically generate position values at a predetermined update interval. The prediction unit is operable to receive a position data request at a first time and predict a position of the rotating load at the first time as a function of at least a subset of the position values generated prior to the first time and a misalignment between the first time and the predetermined update interval to generate an aligned position signal.

Abstract: A method and apparatus for estimating inertia of an electric motor that drives a load wherein the load has a limited range of load travel, the method comprising the steps of identifying an intermediate position along the range of load travel that is separated from a first end of the range of load travel, receiving a sensor signal from a sensor attached to the electric motor, with the load separated from a first end of the range of load travel, increasing a velocity of the electric motor from a first velocity as the load travels toward the first end of the range of load travel, identifying when the load has reached the intermediate position, identifying the motor velocity at the intermediate position as a second velocity, in response to the sensor signal, detecting a first rate of velocity change from the first velocity to the second velocity, acquiring a plurality of torque samples while the electric motor is changing velocity, each torque sample representing an amount of torque generated by the electric moto

Abstract: An improved electronic line shaft provides for a predictor sending predicted position and/or velocity values to servant drives that may be later strobed in by high speed low-latency strobe signals to eliminate network jitter and delay. The predictor may be implemented as a phase lock loop, providing filtering of a master encoder signal together with flexible electronic gear ratio adjustments and other desired control refinements.

Abstract: A method and assembly for synchronizing machine operations, the assembly comprising a reference generator for generating a speed reference signal and a position reference signal, a plurality of slave units, each slave unit including, a mechanical device, a separate motor linked to and driving the mechanical device and a separate unit controller for controlling the unit motor, the unit controller receiving and using the reference signals to control motor operation and a synchronizer receiving the reference signals from the control signal source and simultaneously providing the reference signals to each of the slave unit controllers for use in controlling operation of the motors in a synchronized fashion.

Abstract: A drive unit for controlling a motor includes a position feedback device and a velocity noise filter. The position feedback device is operable to generate a position signal relating to a position of the motor. The velocity noise filter is coupled to the position feedback device and operable to filter the position signal over a predetermined number of samples to generate a velocity feedback signal for the motor.

Abstract: A method for determining motor velocity includes generating an edge signal including a plurality of edges. The edge signal indicates rotational travel of a motor. Edge counts in the edge signal occurring during periodic sample intervals are determined. The edge counts are filtered over a predetermined number of samples. A velocity feedback signal is generated for the motor based on the filtered edge counts. A drive unit for controlling a motor includes an edge detection unit, a position accumulator, and a velocity filter. The edge detection unit is operable to receive a motor position signal and generate an edge signal including a plurality of edges. The edge signal indicates rotational travel of the motor. A position accumulator is operable to determine edge counts in the edge signal occurring during periodic sample intervals. The velocity filter is operable to filter the edge counts over a predetermined number of samples to generate a velocity feedback signal for the motor based on the filtered edge counts.

Abstract: A motor control system for controlling a motor includes control logic and a motor controller. The control logic is operable to generate a control signal at a first periodic time responsive to a synchronization signal. The motor controller is operable to generate a drive signal for the motor based on the reference signal at a second periodic time synchronized with respect to the first periodic time.

Abstract: A method and apparatus for use with a motor controller that receives a command velocity and that applies voltages to drive a motor at the command velocity, the apparatus comprising a dual inertia lost motion assembly including a motor and a load couplable to the motor, the lost motion assembly characterized by at least some lost motion between the motor and the load, the motor and load together characterized by a total assembly inertia, an acceleration error determiner for generating an acceleration error that is the difference between a derivative of the command velocity and a motor acceleration value and a low pass acceleration error filter filtering the acceleration error and having a gain set as a percentage of the total assembly inertia, the acceleration error filter providing the filtered signal to the controller, the controller using the filtered signal to adjust the applied voltages.

Abstract: An apparatus for use with a signal generator and a motor controller includes a velocity compensator, an adjustor, and a velocity regulator. The signal generator provides a reference velocity signal, and the motor controller receives an output signal and uses the output signal to control a torque input signal applied to the motor. The velocity compensator is operable to receive the reference velocity signal, determine a derivative of the reference velocity signal, and generate a velocity compensation signal based on the derivative. The adjustor is operable to adjust the reference velocity signal as a function of the velocity compensation signal. The velocity regulator is operable to compare the adjusted reference velocity signal to a feedback velocity signal and generate the output signal received by the motor controller for adjusting the torque input signal based on the comparison.

Abstract: A method and apparatus for use with a controller for controlling a machine wherein a torque reference value is provided, the method for identifying an error representative of the difference between the torque reference value and the torque applied to the machine and using the error value to modify machine operation.

Abstract: The present method can determine the inertia of an electric motor and the load driven by the electric motor in situations where the electric motor accelerates or decelerates in a non-linear manner. During acceleration and deceleration, the torque produced by the electric motor is sampled periodically and the average values for the acceleration torque and deceleration are calculated. The rates of acceleration and deceleration also are determined. These values are employed to derive a value indicating the inertia.

Abstract: A method and apparatus for essentially eliminating cyclic disturbances in a motor control system, the method including identifying frequencies of undesirable components in a feedback signal that exceed a threshold level and generating a combined signal including sine wave components corresponding to each of the identified frequencies, delaying the combined signal to generate a plurality of identical but phase shifted combined signals, weighting each one of the delayed signals as a function of the magnitude of an instantaneous corrected signal which is the difference between a velocity error signal and a compensation signal and adding each of the weighted signals to generate the compensation signal.