Estimating a Rider’s Compensatory Control Actions by Vehicle Dynamics Simulation to Evaluate Controllability Class in ISO 26262 2019-32-0537

Controllability is defined in ISO 26262 as a driver’s ability to avoid a specified harm caused by a malfunction of electrical and electronic systems installed in road vehicles. According to Annex C of Part 12 of ISO 26262, simulation is one of the techniques that the Controllability Classification Panel (CCP) can use to evaluate comprehensively the controllability class (C class) of motorcycles. With outputs of (i) an index for the success of harm avoidance and (ii) the magnitude of the rider’s compensatory control action required to avoid harm, the simulation is useful for evaluating the C class of the degrees of malfunction that cannot be implemented in practice for the sake of the test rider’s safety.

To aim at supplying data that the CCP can use to judge the C class, we try to estimate the vehicle behavior and a rider’s compensatory control actions following a malfunction using vehicle dynamics simulations. The simulated scenario is the occurrence of unintended deceleration during cornering caused by a malfunction of the electronically controlled combined braking system. The parameter values supplied to the simulation model are set based on data obtained from actual riding tests that were performed. Using this model, we extrapolates the vehicle behaviors and the rider’s compensatory control actions under conditions that an actual riding test cannot be feasible. Moreover, the estimation results demonstrate the likely magnitude of the steering torque relative to the deceleration due to the malfunction as data that the CCP could use to evaluate the C class.