This paper presents the ride diagram, a new way of evaluating and presenting ride comfort Furthermore, a simplified methodology is suggested to test and correlate objective measures of vehicle ride with subjective driver impressions.
The ride diagram is calculated from measured cab accelerations resulting from increased levels of excitation. The basic idea is to graphically visualize how ride comfort changes with excitation. Test drivers are then asked to pair the set of tested vehicles with corresponding curves in the ride diagram. This step assures that the selected measure captures how drivers apprehend changes in vehicle ride.
The suggested methodology is illustrated on trucks with different cab suspension settings. For a given test track increased vehicle speed is used to increase the excitation level. The trucks are also placed in a road simulator to enable easy variation of both excitation type and level. Measurements shown in the ride diagram are compared to mean square and PSD analysis.
Results show that the ride diagram has four main advantages; it is fairly simple to interpret, it shows the absolute vibration level, it considers transient events separately and it shows changes in vehicle character with increasing excitation.