A method of inhibiting stop-start control using gear selector position

Abstract

A method for controlling automatic starting and stopping of an engine (2, fig 1) of a micro hybrid vehicle, the method comprises in step 810 carrying out a validity or a plausibility test of a transmission state sensor TSS (7), in step 820 checking whether an odd and even plausibility test been completed, in step 830 determining if the plausibility tests have been passed and if yes in step 840 enabling automatic stop-start control of the engine (2). If the answer in step 830 is no then in step 850 stop-start control is inhibited and in step 860 a user is warned of a system error. The transmission state sensor TSS (7) provides an indication of a position of a gear selector and includes an odd gear selector position and an even gear selector position. The method reduces a risk of unintended movement of the micro-hybrid vehicle (1) due to erroneous transmission state sensor (7). An apparatus for controlling automatic starting and stopping of an engine is also disclosed, the apparatus comprises a transmission state module which receives a signal from the senor (7) and provides an output to a stop-start controller to inhibit stop-starting if the sensor (7) output is confirmed not to be valid for either or both odd and even gear selector positions.

Description

technical field [0001] The present invention relates to methods for controlling automatic starting and stopping of a vehicle engine, and in particular to determining whether output from a transmission state sensor used to determine the engagement state of a manual transmission fitted to a micro-hybrid vehicle is authentic. Background technique [0002] It is known that micro-hybrid technology fitted to manual transmission vehicles makes it possible to reduce fuel consumption by invoking automatic engine stop and start when the vehicle is stationary. Different engine shutdown and restart strategies are available, such as stop in neutral (SIN) and stop in gear (SIG). In SIN and SIG configurations, there are situations where a reliable signal indicating that the transmission is in neutral is required. This signal is used by the engine management system stop-start logic as a condition to determine whether to allow engine shutdown or restart. This is a safety critical requireme...

AI Technical Summary

Problems solved by technology

This complicates calibrating fixed thresholds to determine the boundaries of any neutral window or in-gear zones that are valid for all transmissions

While it is possible to do some form of transmission-line zero-offset learning or vehicle-line zero-offset learning to learn the difference in the transmission's neutral park position, the process introduces risk, i.e. the learning may not be performed correctly, or when the transmission is changed in use, the learning cannot be updated and thus introduce errors in the learned offset

This can have serious consequences, namely unintended vehicle movement during stop-start maneuvers and must therefore be avoided

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