Electrohydraulic servodevice for position control
AssigneeNireco Corporation
InventorTakeshi Aihara
Life of this patent
Estimating the term…
Abstract
The position of a controlled system is regulated with a hydraulic actuator, which is directly linked to a hydraulic pump. The pump is driven in either direction by an electric motor, which is controlled by the output of rotatory direction and driving power generated from a controller based on a desired position and the feedback input of the actual position of the controlled system and the rotatory speed of the electric motor. The controller further includes a gain-variable amplifier for amplifying a deviation of the controlled value from a desired value with a gain characteristic curve of a shape appropriate to the controlled system, attaining a stable and well follow-up control of position.
Claims9
An electrohydraulic servodevice comprising:
- (a) a hydraulic actuator for position control of a controlled system;
- (b) a hydraulic pump rotatable in both directions for driving said hydraulic actuator;
- (c) an electric motor for driving said hydraulic pump in both directions;
- (d) a position detector for detection of the position of said controlled system;
- (e) a tachometer for measurement of the rotatory speed of said electric motor;
- (f) a position-deviation operation element for deriving a deviation of the position detected by said position detector from a desired value;
- (g) a gain-variable amplifier for amplifying the output of said position-deviation operation element with a gain characteristic curve of predetermined shape;
- (h) a speed-deviation operation element for deriving a deviation of said rotatory speed from the output of said gain-variable amplifier;
- and
- (i) an output element for feeding the rotatory direction and driving power to said electric motor based on the output of said speed-deviation operation element.
An electrohydraulic servodevice comprising:
- (a) a reel or guide roll for transfer of a web;
- (b) a hydraulic actuator for position control of said reel or guide roll;
- (c) a hydraulic pump rotatable in both directions for driving said hydraulic actuator;
- (d) an electric motor for driving said hydraulic pump in both directions;
- (e) an edge-displacement detector for detection of the edge displacement of said web;
- (f) a reel displacement detector for detection of the displacement of said reel or guide roll;
- (g) a tachometer for measurement of the rotatory speed of said electric motor;
- (h) a gain-variable displacement amplifier for amplifying the displacement of said reel or guide roll with a predetermined gain;
- (i) a gain-variable combination amplifier for amplifying a combined value of the outputs of said gain-variable displacement amplifier and said edge-displacement detector with a gain characteristic curve of predetermined shape;
- (j) a deviation operation element for deriving a deviation of the output of said gain-variable combination amplifier from the output of said tachometer;
- and
- (k) an output element for feeding the rotatory direction and driving power to said electric motor based on the output of said deviation operation element.
Dependencies are inferred from the claim text.