Method for detecting an extreme value position of a movable part

US4722313A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Rolf Kohler · Schwieberdingen, DE
• Gunther Plapp · Echterdingen, DE

Key dates

• Filing date: Dec 13, 1985
• Grant date: Feb 2, 1988
• Expiry date: Dec 13, 2005

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02D2250/16
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A method is disclosed for detecting an extreme value position of a movable part by means of a position detecting sensor. The method is especially suitable for detecting the idle position of the throttle flap of an internal combustion engine with the aid of a potentiometer. In this method, a stored value (extreme value) corresponding to the extreme position is corrected upon the detection of deviating measured values, provided that the deviating measured values lie within a correction range around the extreme value. The range of movement of the movable part has to lie within the range coverable by the position sensor. After a predetermined number of identical measured values are sensed in the correction range during an operating cycle, such a measured value is stored in memory as the new extreme value. For dynamic adaptation, this next extreme value is modified cyclically, preferably prior to each operating cycle, by a predetermined value away from the outermost position. While detecting the extreme position with a high accuracy, the method of the invention has a very small hysteresis, with the full function capability being restored after a short period, even under irregular operat…