Development of an Online Algorithm for detection of status of power transmission (engaged/ disengaged Gear) for Electronic Stability Control (ESP/ABS)

Abstract

In automobiles, line of transmission consists of Engine, propeller shaft, drive shaft Gears, Clutches and wheels. Power is transmitted via clutches, which engage or disengage in order to open or close the whole power transmission, from engine to wheels. Wheels are the only point of contact to the surface. All the forces acting on the vehicle whether tracking or braking act on the wheels. Knowing exactly maximum forces possible and the actuators participations and roles in the resulting surfaces lets better control of brakes and engine systems. On low mue (μ) surfaces engine drag force may lead to very high braking force resulting instable and not steerable vehicle. Drag torque controller, a sub controller of ABS system is being used to control engine drag after downshift or during ABS braking. Engine Drag Torque Controller (DTC) prevents the driven wheels from locking on slippery surfaces where engine drag is a major cause for locking wheels. DTC maintains steer ability, stability and boosts safety. Missing DTC measure while being engaged at high brake slips would lead to instable and not steerable. In most manually transmitted gearboxes, reliable monitored engaged clutch information is not provided. Correlation between engine speed, wheel speeds and other acting forces may be used to detect drive train engagement status. Engaged gear information is required to allow DTC (Drag torque controller) activations. In order to ensure that power transmission is closed and engine drag is one of the major braking force providers, clutch engaged information has to be detected. Misdetection of engaged gear (no DTC interventions) is safety critical, especially 4WD and RWD vehicles on low mue surfaces. Wrong detection of disengaged gear (wrong DTC intervention) is a comfort issue and may lead to engine noise. The purpose of this thesis is to use the vehicle data (engine speed, wheel speed, ABS control information, drive mode) and detect suspension of Gear engaged for DTC controlled situations