JOYSTICK CONTROLLED DRIVING FOR DRIVERS WITH DISABILITIES. A DRIVING SIMULATOR EXPERIMENT

A driving simulator experiment was conducted to investigate two design features of four-way joystick systems used for vehicle control (accelerator, brake and steering). Effects of active force feedback and decoupled speed and steering control were investigated. These were features expected to facilitate driving with joystick systems. Time lags were made similar to what is found in conventional primary car controls, as those found in existing joystick systems seem to complicate usage and prolong learning. The joystick was designed for drivers with severe locomotor disabilities. Sixteen drivers with spinal cord injuries at a cervical level participated - all inexperienced with joystick driving. All participants drove on a rural road and performed a double lane change manoeuvre task. It was found that the decoupling provided better control and less workload, especially for those eight drivers with better hand and arm function. Active force feedback together with decoupled control was found positive for the same subgroup and provided better control in the lane change manoeuvre. However, drivers with less arm and hand function preferred passive feedback, and active feedback was even found disturbing. In general, the tested joystick was found to be very easy to learn, which was attributed to the short time lags.