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:
May. 13, 2003
Filed:
Apr. 15, 2002
Paul D. Perry, Chatham, CA;
Raymond Rasokas, Thamesville, CA;
Siemens VDO Automotive Inc., Chatham, CA;
Abstract
A leak test system and method for a motor vehicle fuel system. A pump forces air under pressure into vapor containment space. The pump operates in accordance with steps established by a processor. The pump creates superatmospheric target pressure in the space during an initial charging phase step, and after completion of that step, the pump is duty-cycled to regulate pressure in the space at the target pressure. A duty cycle comprises a burst of individual air pulses, one after another. The processor processes data corresponding to the duty cycle using P-I-D operations to set the number of pulses in a succeeding burst for regulating the pressure. When stability of the duty cycle is attained, the period of the duty cycle indicates leakage from the space.