A System Safety Perspective into Chevy Bolt’s One Pedal Driving 2019-01-0133
The Chevy Bolt’s One Pedal Driving feature is a new electrification propulsion enhancement that allows the driver to accelerate, decelerate and hold their vehicle stationary by just using the accelerator pedal. With this new feature, the driver is relieved of having to switch between pressing the accelerator pedal and brake pedal to slow, stop and hold the vehicle stationary to operate the vehicle. While this feature provides a convenience to the driver, it also presents a paradigm shift in driver engagement and control system responsibility for executing certain functions that the driver was traditionally responsible to perform. Various system safety techniques were involved in the development of such a feature both from a traditional ISO 26262 functional safety perspective as well as a Safety of the Intended Function (SOTIF) perspective. The safety considerations of this feature included not only the traditional failures scenarios of the sensors, actuators, controllers, serial data, etc. involved with the feature and its functions but also the driver anticipated behavior that may potentially result from using the feature. For instance, when the driver releases the accelerator pedal and slows down to a stop using the feature, they are no longer pressing the brake pedal and may no longer be actively engaged or paying attention while the control system is holding the vehicle stationary. It is in this case that safety considerations are now needed for scenarios such as a driver who exits the vehicle without putting the vehicle in park or a driver who becomes distracted inside the vehicle and can no longer react to a failure of the control system which may cause the vehicle to inadvertently move. This paper will explore the high level safety techniques and considerations used in this customer facing feature as a method for outlining a more generic approach for safety considerations for similar features.
Richard A. Kulas, Helen Rieland, Jenna Pechauer
General Motors, General Motors Proving Ground