Controllability (C class) represents the level of the ability to avoid harm and is one of the parameters that determine the Automotive Safety Integrity Level in the ISO 26262 functional safety standard, which applies to the electrical and/or electronic systems. This study aimed to consider an appropriate C class evaluation technique for expert riders in applying ISO 26262 to motorcycles.
This study attempted to show a C class evaluation method without deviation by the riders and presented examples of the evaluation of three hazardous events in actual vehicle tests. In addition, riders' comments regarding their understanding of the circumstances that resulted in the evaluation were collected, and the correspondence of these comments was examined.
We selected “unintended acceleration” or “unintended deceleration” due to the malfunction of the electronic throttle control system as hazard examples and conducted tests to reproduce hazardous events. The expert riders evaluated the C class using the evaluation method that we considered. For unintended acceleration when following a preceding vehicle or during turning, the C classes were evaluated from C0 (control in general) to C3 (difficult to control or uncontrollable) depending on the acceleration level. The results of C class evaluation by all riders were found to be similar. For unintended deceleration during turning, all riders evaluated it as C0 at all deceleration levels.
The specific C class evaluation considered in this study is believed to be a useful technique because the C class of each hazardous event was evaluated by expert riders via actual vehicle tests.