This report describes the institute's road roughness simulator. The simulator consists of a truncated car body complete with all controls. A projector screen is placed in front of the car. By turning the steering wheel in the simulator the driver can control the projector and the film and thus "steer" the car along the road. A synthetically generated noise signal is added to the steering wheel movement made by the test driver. In this way the car will not drive straight without compensation from the driver. In order to simulate road roughness a synthetically generated noise signal is used, whose frequency components and amplitude can be varied. The performance recordings made during each experiment comprise a number of parameters. Recordings are made of the driver's pulse rate, steering wheel movements, foot movements and various reaction times in emergency situations. A computer handles all data acquisition and calculations using these values. The driver is exposed to two types of stimulus: (1) a headlamp which is lit in front of the bonnet and (2) a weaker light which is lit behind him and can only be seen in the rear-view mirror. The driver's reaction to stimulus 1 is to release the accelerator and to brake as quickly as possible and to stimulus 2 only to release the accelerator. A number of reaction times are measured in conjunction with these stimuli; the time until the driver releases the accelerator, the time until his foot is above the brake pedal and the time until full braking pressure has been reached.
Abstract