Position control apparatus

Abstract

A deflection amount Ps representing a difference between a position detection value Pl of a driven body and a position detection value Pm of a motor is detected. A position calculator proportional constant Kp, a time constant Tp of a first-order lag circuit that inputs a the deflection amount Ps, and a time constant Tv of a first-order lag circuit that inputs a difference between a speed detection value Vl of the driven body and a speed detection value Vm of the motor are changed based on the deflection amount Ps.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention and, together with the description, serve to explain the principles of the invention, in which:

FIG. 1 illustrates a full-close control system according to an embodiment of the present invention;

FIG. 2 is a block diagram illustrating an example of a deflection detector according to an embodiment the present invention;

FIG. 3 illustrates a full-close control system according to an embodiment of the present invention;

FIG. 4 is a block diagram illustrating an example of a deflection detector according to an embodiment of the present invention;

FIG. 5 illustrates a conventional full-close control system;

FIG. 6 is a block diagram illustrating a conventional full-close control system;

FIG. 7 illustrates a conventional full-close control system;

FIG. 8 illustrates a conventional full-close control system;

FIG. 9 is a graph illustrating gain characteristics according to the conventional full-close control system;

FIG. 10 is a graph illustrating gain characteristics according to the conventional full-close control system;

FIG. 11 is a graph illustrating gain characteristics according to the conventional full-close control system;

FIG. 12 is a graph illustrating gain characteristics according to the embodiment of the present invention; and

FIG. 13 is a graph illustrating gain characteristics according to the embodiment of the present invention.

Claims

1. A position control apparatus which performs full-close control for controlling a position of a driven body driven by a motor, the apparatus comprising: a motor position detector;a driven body position detector configured to detect the position of the driven body;a subtracter configured to calculate a deflection amount representing a difference between a position detection value obtained from the motor position detector and a position detection value obtained from the driven body position detector; anda deflection detector configured to change a proportional constant of a speed command calculator based on the deflection amount.

2. A position control apparatus which performs full-close control for controlling a position of a driven body driven by a motor, the apparatus comprising: a motor position detector;a driven body position detector configured to detect the position of the driven body;a subtracter configured to calculate a deflection amount representing a difference between a position detection value obtained from the motor position detector and a position detection value obtained from the driven body position detector;a position detection value calculator configured to add an output of a first-order lag circuit inputting the deflection amount to the position detection value obtained from the motor position detector and output a position feedback value; anda deflection detector configured to change a first-order lag circuit time constant of the position detection value calculator based on the deflection amount.

3. A position control apparatus which performs full-close control for controlling a position of a driven body driven by a motor, the apparatus comprising: a motor position detector;a driven body position detector configured to detect the position of the driven body;a subtracter configured to calculate a deflection amount representing a difference between a position detection value obtained from the motor position detector and a position detection value obtained from the driven body position detector;a speed detection value calculator configured to add an output of a first-order lag circuit to the motor speed detection value and output a speed feedback value, wherein the first-order lag circuit inputs a difference between a motor speed detection value obtained from a motor position detection value and a driven body speed detection value obtained from a driven body position detection value; anda deflection detector configured to change a first-order lag circuit time constant of the speed detection value calculator based on the deflection amount.

4. The position control apparatus according to claim 1, further comprising a deflection detector configured to determine whether the deflection amount exceeds a predetermined threshold and display a status of the deflection amount when the deflection amount exceeds the threshold.