摘要:
The purpose of the present invention is to provide a method for estimating load inertia and a method for adjusting control parameters. To achieve this aim, a load position control test is performed in a load position control system, based on a feedback control system (21) and a first position deviation (Δθ) generated at a prescribed load position (θL) is estimated. Then, in a load inertia estimation model (60) which is a model of a load position control system, a load position control simulation of a feed system model is performed based on a feedback control system model, a load inertia (JL) included in the feed system model is adjusted, and the load position control simulation repeated until a second position deviation (Δθ) that generated at this time at the prescribed load position equals the first position deviation. As a result, the load inertia for the feed system model at that time is estimated to be the load inertia for a feed system in an actual machine if the second position deviation equals the first position deviation. In addition, coefficients (a3-a5) for an inverse characteristic model (50) are set using this estimated load inertia.
摘要:
A control unit performs servo control of a table, which is a load, by performing feedback control of a servomotor. An inverse characteristic model performs feedforward compensation control by obtaining a speed compensation signal that compensates for the dynamic errors of a mechanical system. When the rigidity of a screw section of a ball screw along the axial direction changes, a rigidity-change compensation unit changes the rigidity value of the screw section along the axial direction that is included in the compensation control transfer functions of the inverse characteristic model, in accordance with the change in rigidity. Thus, the servo control apparatus compensates for such changes in rigidity and performs accurate servo control of the position of the table, even when the ball screw of a feeding mechanism expands or contracts due to secular change or change in temperature, and rigidity along the axial direction changes.