Method and apparatus for controlling an actuatable protection device with off-road and rollover detection

A vehicle safety system comprising:

• an actuatable restraint for helping to protect a vehicle occupant;
• and
• a controller for controlling actuation of the actuatable restraint in response to a vehicle rollover event;
• wherein the controller is configured to execute an off-road detection metric configured to determine whether the vehicle is being operated under normal usage or off-road usage;
• wherein the controller is also configured to execute a rollover discrimination metric configured to discriminate the occurrence of a rollover event in response to a vehicle roll rate (R_RATE) having a magnitude that exceeds one or more predetermined roll rate thresholds;
• wherein, in response to determining that the vehicle is being operated under normal usage, the controller is also configured to execute a normal rollover deployment algorithm to detect a vehicle rollover in response to the rollover discrimination metric discriminating the rollover event;
• and
• wherein, in response to determining that the vehicle is being operated under off-road usage, the controller is also configured to execute an off-road rollover deployment algorithm to detect a vehicle rollover in response to the rollover discrimination metric discriminating the rollover event.