HOW HAPTIC ASSIST REDUCES VISUAL DEMAND AND FREES ATTENTION
We are interested in determining both primary intended and secondary benefits of using haptic assist in manual control tasks. To study this, we designed a controller that shared authority of steering a car with the driver in order to improve the lane-keeping performance and make driving easier. The control was shared by applying torque to the steering wheel with limited impedance so that the driver could still override the controller. We showed experimentally using a PC-based driving simulator that this controller improved the path following performance of the driver through the use of haptic assist, however the fact that the driver’s performance improved in path following is really a no-brainer because we designed the controller specifically for that purpose. The more interesting question is what additional benefit does the driver gain from sharing control with an automation system. Experimentally we showed that the driver benefited in two other ways. First, using the visual occlusion method, we showed that the driver’s need for visual feedback was reduced. Additionally, we inferred a freeing of attention from the primary driving task because we measured a faster reaction of the driver in a secondary task. These results show that with haptic assist, the driver’s performance may be improved in multiple ways.
Sketch of the experimental setup of a simulated driving task with haptic assist in the steering wheel.