Current Control Fail Safe of a Transfer Case During Position Sensor Faulted State

摘要

A position sensor is used in the Transfer case to monitor actuator position. This actuator position is translated to clutch force and further to clutch torque capacity. So, position sensor is a crucial part of the Transfer case functionality. Any malfunction in the sensor can lead to complete failure of the transfer case functionality. Transfer case is a set of gears or chain which transfer power to front and rear wheels. There are different modes in the transfer case which controls the power distribution between front and rear wheels. The different modes in 2 speed transfer case are 4 Wheel drive Low (4LOW), Neutral, 2 Wheel drive High (2WD) and 4 Wheel drive High (4WD) or 4 Wheel Auto (4Auto). In 1 speed transfer case, there is only one gear ratio so the different modes are 2 Wheel drive High (2WD) and 4 Wheel drive High or Auto. Transfer case software execute the shifts between these modes either based on driver request or automatically based on vehicle conditions.