Control device having excessive-error detection function
AssigneeFanuc Corporation
InventorsYasusuke IWASHITA, Tadashi OKITA, Hiroyuki KAWAMURA, Junichi TEZUKA
Life of this patent
Estimating the term…
Abstract
Abnormality of a position error is quickly detected in a control device in which feedforward control is introduced. A position error estimation processing unit calculates a position error estimation value Err, for example, from the equation V/PG×(1−α) (V: first order differential of position command, PG: position gain in position controller, α: feedforward coefficient in feedforward term calculating unit), and abnormality of the position error is detected using an excessive-error detection level calculating by adding a margin ΔE to the position error estimation value.
Claims6
A control device comprising:
- a position controller calculating a first velocity command by multiplying by a position gain a position error detected between a position command and a position feedback from a control target;
- a feedforward term calculating unit calculating a feedforward term by multiplying a time differential of said position command by a feedforward coefficient;
- a velocity controller controlling the velocity of said control target based on a second velocity command obtained by adding said feedforward term to said first velocity command;
- a position error estimation value calculating unit calculating a position error estimation value from said position command, said position gain, and said feedforward coefficient;
- and
- a position error abnormality judging unit judging said position error to be abnormal when said position error is greater than said position error estimation value by more than a predetermined value.
Dependencies are inferred from the claim text.