The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 21, 2000
Filed:
Apr. 30, 1998
Kenji Irokawa, Ibaraki-ken, JP;
Tomohiko Aki, Ibaraki-ken, JP;
SMC Kabushiki Kaisha, Tokyo, JP;
Abstract
When a reference signal is changed stepwise, a switch is open, and a pneumatic device with a dead time starts being actuated in a PD control mode. After elapse of the dead time, when a controlled variable changes and a position detector produces an output signal, a speed signal which is a differential of a feedback signal changes from a value '0'. When a speed detector detects when the speed signal is equal to or greater than a predetermined value, a switching signal is applied to close the switch. After the switch is closed, the pneumatic device is actuated in a PID mode. An overshoot or an oscillation in a controlled variable due to the integration of the dead time in an I control mode can be suppressed.