The primary function of an Airbag Control Module (ACM), referred to as the Sensing and Diagnostic Module (SDM) by General Motors (GM), is to detect crashes, discriminate crashes, evaluate crash severities, deploy the appropriate restraints, including airbags and pretensioners, and perform system diagnostics. A secondary function of the SDM is to act as an Event Data Recorder (EDR) which records data during the time periods just prior to (pre-crash) and during a crash event. This data consists of restraint and vehicle system data which is collected, processed, and stored in the EDR. Data stored in the EDR is intended to be retrieved after a crash. This data provides operational information on the vehicle’s occupant protection system and other vehicle systems to assess system performance, aid in crash reconstruction, and support improved vehicle safety.
A series of vehicle test maneuvers were conducted while injecting a non-deployment crash pulse directly into the SDM to cause the SDM to record an event with related restraint and vehicle system (pre-crash) data. These tests include a variety of constant speed, acceleration, braking, and steering maneuvers. During these maneuvers, vehicle system data was recorded directly from the serial data bus using a passive monitoring tool, tapped sensors, video cameras, and independent onboard instrumentation and that data was compared with the data recorded within the SDM EDR.
This paper addresses the operation and accuracy of the vehicle system data recorded for a crash event by the SDM, specifically the SDM50 and its utilization of the GM Vehicle Intelligence Platform (VIP) vehicle serial communication bus. Evaluation of this data provides an understanding of the accuracy of the vehicle system data recorded for a crash event by the SDM.