Driver Response to Controllable Failures of Fixed and Variable Gain Steering (vehicle design)
Funding Organisation: Jaguar Cars
Active Front Steer (AFS) is a variable gain steering system that can be a useful driver aid: less wheel input is required to steer at low speeds than a more traditional fixed-gain (FG) system. However, should an AFS system fail, the sudden change in steering gain is potentially hazardous. Using the LADS, forty drivers participated in this single-blind study which compared driver response to both operational and failed AFS compared to a FG system with both functional and failed power steering. At low speeds, whilst negotiating an intersection, drivers rated AFS higher than FG for ease of steering. There were also trends suggesting that AFS failure was easier for drivers to control than the loss of power-assist to the FG system. At high speeds, AFS also showed advantages: drivers rated AFS higher and demonstrated fewer steering micro-corrections, intimating that maintaining control of the vehicle was less demanding with AFS.