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 virtual encoder is provided as a software component of a motor drive that integrates a command speed to produce a desired position drive signal. The desired position drive signal is converted to an actual position drive signal that is constantly maintained within a predetermined integer error margin of the desired position drive signal.
Abstract:
A method and apparatus for motor control tuning wherein an extremely accurate estimate of inertia is determined by using the second derivative of a desired motor velocity and the torque supplied to a motor is altered as a function of inertia.
Abstract:
A method for control of servomotors includes limiting velocity feedforward as a second input to a velocity control loop in response to a velocity command, which is a first input, reaching a predetermined limit. Gain parameters for proportional and integral portions of a velocity-torque control loop and for the proportional and integral portions of the velocity feedforward loop may be adjusted independently to obtain varying control responses from the control system. The method is carried out in a microcomputer-based control module for an industrial controller.
Abstract:
A method and apparatus for use with a plant drive system that receives a reference command signal and generates a torque command to drive a plant, the method for estimating plant inertia and comprising the steps of providing a reference model that models the plant, the model receiving the reference command signal and generating a model output signal as a function thereof, identifying a plant output signal, mathematically combining the reference command signal and the plant output signal to generate a first error value, mathematically combining the plant output signal and the model output signal to generate a second error value, mathematically combining the first and second error values to generate an inertia estimate value and using the inertia estimate value to modify the torque command thereby providing a modified torque command signal to drive the plant.
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:
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 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 generate a velocity feedback signal for the motor based on the filtered edge counts.
Abstract:
In a real-time system of a digital control system, in order to prevent a single program sequence (PS2) of a non-time-critical computing process ("task") from using up a load-dependently disproportionate amount of the total computing time still available, the program sequence (PS2) is classified as a subordinate computing process (R14) that has a running-time limit (LZF). Sequences of program steps that are preferably not to be interrupted are in this case protected from interruption by a lock, the original running-time limit (LZG) being able to be run over only within predetermined limits.
Abstract:
A method and apparatus for control of one or more torque-regulated motors in a controlled system in which a feedforward velocity component is subtracted from an output of proportional-integral velocity regulator to soften the command response of the motor control, independent of torque disturbances reflected in the velocity feedback path. The velocity feedforward path is decoupled from the velocity feedback path. In a preferred embodiment, a digital-type motor controller is used to practice the method in controlling a paper processing line.