Abstract
Keywords electric steering, drivers feel, vehicle response, handling, steering model
Abstract
Electric steering systems come to the market instead of traditionally hydraulic power assisted steering systems, but support of the expected good steering feel is a problem. Steering with an electric motor generates several problems, e.g. electric or digital feel, catch-point or stability problem. However these systems can provide additional functionality in direct comparison with hydraulic power assisted systems from speed variable assist to active safety systems, the steering feel must always be at least as good.
The authors goal is to analyze what the driver feels on the steering wheel from the road and the vehicles dynamic behaviour, and determine the parameter ranges where the driver experiences good steering feel. The effects on the steering feel for different vehicles and several parameter setups of electric steering systems will be presented. The authors derive the objective analysis of the subjective steering feel, and will try to quantify it. Several steering feel properties will be shown, which have been validated in a real vehicle during dynamic measurements. The authors try to establish an overall basis for design criteria of the electric steering system.