Impact of a visual and haptic driver advice and preview system on a range optimized way of driving in electric vehicles
Today one of the disadvantages of electric vehicles is still the lower driving range in comparison to conventional vehicles resulting in subjective fear of drivers not to reach their destination. One approach to extend the driving range is to change the driver behaviour to a more efficient and intelligent way in terms of energy usage in certain driving situations. To realize a change in driver behaviour it is necessary to support and motivate drivers by means of driving advice and situation preview. This paper introduces a visual and haptic on trip Human Machine Interface (HMI) for electric vehicles, developed with the purpose to lead drivers to a range optimized way of driving, and the results of the associated driving simulator study about the impact of that HMI on such a range optimized way of driving in electric vehicles. The HMI presented in this paper is the result of an iterative development process with several sub studies and consists of many elements to support the driver in a range optimized way of driving. Central element of the visual HMI is a preview and advice system that provides drivers with information about the current and upcoming situation and advice. It is complemented by visual feedback elements that e.g. rate the efficiency of the current driving style. The visual advice is supported by haptic advice elements like a continuous haptic feedback on the acceleration pedal, when the driver exceeds the speed limit respectively an eco friendly speed, and a "recuperation" advice that provides a pulsation of the acceleration pedal at the time of an optimal start of recuperation manoeuvres regarding energy efficiency. The haptic advice is provided by a force feedback pedal. The impact study was conducted in ika's static driving simulator with twenty seven subjects. Beside an objective evaluation of the driving parameters, an introductory interview on demographic data and driving experiences as well as questionnaires on the acceptance of three different HMI versions (no advice, visual advice preview, visual haptic advice preview) are evaluated. The evaluation shows a positive impact of the developed visual as well as visual haptic advice and preview system on a range optimized way of driving in electric vehicles. Hereby the visual haptic advice system showed compared to a baseline (without advice) and a visual advice system the biggest impact on the driving behaviour. Language: en