Since we upgraded our Drive Safety DS-600C driving simulator with the new version of the software, we noticed that the reading for the steering wheel angle was incorrectly calibrated. Namely, even though the steering wheel can be rotated about 1.5 full turns in both directions (which would amount to approximately -540° to +540° lock-to-lock) the steering wheel data was reporting angles from approximately -360° to +360°. This meant that the calibration of the steering wheel optical encoder was incorrect and had to be fixed.
Fortunately, all of the parameters related to the car dynamics are easily accessible in the file called default.cab, located on the host computer in /home/sim/vection/system/devices/. This file is essentially an xml file and the parameter we are interested in is encodergain located under the steeringencoder sensor section. In order to set the value for the encoder gain properly, we have to establish the actual relationship between the angle on the steering wheel and the angle reported by the steering wheel optical encoder. For this purpose we used a protractor mounted on the steering wheel:
The procedure for finding the proper encoder gain consists of the following steps. First, log onto the host computer and navigate to the above folder. Second, set the encoder gain to 1 in the default.cab file. Third, start the simulation and rotate the steering wheel to some known angle indicated by the protractor (in our case 45°). And finally, divide the actual angle on the steering wheel (indicated by the protractor) by the angle reported by the steering encoder in the data collection to obtain the desired encoder gain. After setting this new encoder gain, the reading reported by the steering encoder was correct.