Positioning control system
AssigneeHitachi, Ltd.
InventorShigeo Moriyama
Life of this patent
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Abstract
In a positioning control system of the type which controls an object to be controlled to a target position by the use of a servo system, the present invention is characterized in that when a position deviation between the present position of the object to be controlled and the desired target position is smaller than a predetermined value, the servo system is actuated for a first period of time in accordance with the position deviation by means of a control signal which is greater than that normally warranted by the position feedback gain which is provided in the servo system, and is thereafter changed over to a servo system which is actuated by the position feedback gain either after a predetermined time or when a predetermined velocity has been achieved.
Claims11
A positioning control system for positioning an object at a desired target position by use of a servo system comprising:
- means for measuring the present position of said object;
- means for calculating the position deviation between the present position and the desired target position of said object and for generating a control signal representing said position deviation including means for comparing the position deviation with a predetermined value;
- a servo system including variable gain servo means for moving said object to the desired target position in response to said control signal on the basis of a first value of position feedback gain, when the position deviation is greater than said predetermined value;
- and control means for initially increasing the gain of said servo means to a second value to provide a control signal greater than the control signal provided by said first value of position feedback gain when said position deviation is smaller than said predetermined value and for thereafter changing the gain of said servo means back to said first value to position said object at the desired target position.
In a positioning control system for moving an object from a starting position to a target position including a servo system having a predetermined feedback gain of the type in which a control signal to a servo motor for driving the object is proportional to the position deviation with respect to the desired target position, the improvement comprising means for calculating when the position deviation between the starting position of the object and the target position is less than a predetermined value and control means responsive to said calculating means for initially increasing the gain of said servo system above said predetermined feedback gain as the object is moved from said starting position and then reducing the gain to said predetermined value prior to the object reaching said target position.
Dependencies are inferred from the claim text.