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Event data recorders (EDRs) were harvested and imaged after Insurance Institute for Highway Safety (IIHS) 56 km/hr frontal and 64.4 km/hr frontal offset crashes of 15 different brands of 2016-2022 vehicles. The speed and delta-V in the EDR were compared to reference instrumentation. Speed data was accurate within the generally accepted range of +/-4%. The 40% overlap tests had generally similar vehicle kinematics, and their delta-Vx data was accurate. However, there was a much greater variance in the small (25%) overlap tests. Some outliers in the small overlap delta-Vx tests required further analysis using overhead video analysis. The video analysis more closely matched the EDR recorded values. These offset tests create significant post-crash rotation, and both EDR and IIHS instrumentation were affected by their location away from the center of gravity. The Y-axis was affected much more than the X-axis.

Earlier research1 suggests there may be positive offset in the longitudinal G sensor in Toyota Corolla Gen 02 EDR’s. This research tests if a similar offset is present in Toyota Gen 04 EDR’s in the 2007 Yaris. A series of low speed forward and rearward collisions into a stationary vehicle were conducted. In addition to the installed vehicle ACM, additional identical “ride along” ACM’s were installed back to back, one front facing and one rear facing. The vehicle was also instrumented with a video VBOX to record speed at impact, and with the high precision “IST” accelerometer reference instrumentation. ACM’s facing toward the crash under-reported the negative longitudinal Delta V. After the initial impact was over, these forward facing ACM’s had a positive slope and at the end of the 200 ms recording were reporting a positive net Delta V, indicating a G sensor bias. The ACM’s facing away from the crash over reported the positive longitudinal Delta V.

2013 and 2014 Ford Flex vehicles and airbag control modules with event data recorders (EDRs) were tested to determine the accuracy of speed and other data in the steady state condition, to evaluate time reporting delays under dynamic braking conditions, and to evaluate the accuracy of the stability control system data that the module records. This recorder is from the Autoliv RC6 family and this is the first known external research conducted on post 49CFR Part 563 Ford EDRs. The vehicle was instrumented with a VBox and a CAN data logger to compare external GPS based speeds to CAN data using the same synchronized time base. The vehicle was driven in steady state, hard braking, figure 8 and yaw conditions. The Airbag Control Module (ACM) was mounted onto a moving linear sled. The CAN bus data from driving was replayed as the sled created recordable events and the EDR data was compared to the reference instrumentation.

Kia and Hyundai released publicly available tools in the spring of 2013 to read model year (MY) 2013 vehicle event data recorders (EDRs). By empirical testing, this study determined the tools also read data from some 2010-2012 models as EDRs were phased in by the manufacturer. Fifty-four (54) MY 2010-2012 airbag control module EDRs from the National Highway Traffic Safety Administration's (NHTSA) New Car Assessment Program (NCAP) crash tests were downloaded direct-to-module. The vehicles analyzed were exposed to frontal, side moving deformable barrier (MDB), and side pole tests. The EDR data was compared to the reference instrumentation for speed and Delta V data. Other data elements were also tabulated but are not evaluated for accuracy because they were not fully exercised during the crash tests, the reference instrumentation was not available, or they were outside the scope of this paper.

This study evaluates the accuracy of 41 Event Data Recorders (EDR) extracted from model year 2012 General Motors, Chrysler, Ford, Honda, Mazda, Toyota, and Volvo vehicles subjected to New Car Assessment Program 56 kph full-frontal barrier crash tests. The approach was to evaluate (1) the vehicle longitudinal change in velocity or delta-V (ΔV) as measured by EDRs in comparison with the high-precision accelerometers mounted onboard test vehicles and (2) the accuracy of pre-crash speed, seatbelt buckle status, and frontal airbag deployment status. On average the absolute error for pre-crash speed between the EDR and reference instrumentation was only 0.58 kph, or 1.0% of the nominal impact speed. In all cases in which the EDRs recorded the seatbelt buckle status of the driver or right front passenger, the modules correctly reported that the occupants were buckled. EDRs reported airbag deployment correctly in all of the tests.

Prior EDR testing methodologies required setting events in the airbag control module in the vehicle during controlled driving behavior. Duplicating events was nearly impossible, and it was difficult to separate how much differences in recorded speeds to reference speeds was due to measurement error, wheel slip, reporting time delays, or data truncation within the EDR. Recording thresholds have also increased making non-deployment and deployment events closer in magnitude, increasing the risk of accidentally exceeding the deployment threshold while setting events. The new methodology eliminates the risk of accidentally deploying airbags while gathering GPS and CAN bus data in the test vehicle. The techniques presented in this paper also allows gathering of data in vehicle without tampering with the airbag control module, which reduces the potential liability to testers using rental or borrowed test vehicles.

Independent verification of the accuracy of data from Event Data Recorders (EDRs) is useful when using the information to help reconstruct a crash. To this end, the accuracy of the EDR function of the Airbag Control Module (ACM) was tested on 2010 and 2011 Toyota Camry sedans during straight line operation. During steady state operation, and maximum ABS-braking runs starting from approximately 80 km/h (50 mph), and 113 km/h (70 mph), non-deployment events were artificially induced to store event data. Following each run, the EDR was imaged using the Bosch Crash Data Retrieval (CDR) system. The CDR reported speed values were compared to Racelogic VBox differential GPS speed records. Data recorders were also used to monitor the vehicle Controller Area Network (CAN) bus traffic, including the indicated speed, brake pressure, engine RPM, and accelerator pedal position. The speed and RPM reporting algorithms stated in CDR Data Limitations were confirmed.

The accuracy of the Restraint Control Module (RCM) Event Data Recorder (EDR) was tested on a 2010 Ford Flex during both straight line steady state and maximum ABS braking. Six runs were made starting from 48 kph (30 mph), six runs starting from 80 kph (50 mph), and six runs starting from 113 kph (70 mph). Nondeployment events were artificially induced after a period of steady state driving followed by maximum braking for the last 2.5 seconds prior to creating the event, intended to simulate braking just prior to a crash. Following each run data was collected from the RCM EDR using the Bosch Crash Data Retrieval system. A Racelogic VBOX SL3 20 Hz differential GPS speed data recorder also served as a data acquisition system for vehicle CAN bus speed, accelerator position, RPM, and brake tape switch data. Graphs of RCM speed/brake/accel pedal data versus VBOX speed and other data over time are presented.

The accuracy of the Powertrain Control Module Event Data Recorder was tested during vehicle yaw and rotation on a flooded skid pad at the Michigan State Police training facility in Lansing, MI. The low friction of the skid pad allowed longer, slower rotations that allowed more detailed study of the behavior. The vehicle was deliberately put into rotation and allowed to rotate to rest under three different conditions: heavy throttle applied initially, heavy braking applied and held, and light to no throttle applied. Six runs were made under each condition. Data was collected from the PCM EDR and compared to a VBOX III (with IMU) 100 Hz differential GPS speed and yaw rate measurement system from which slip angle could be calculated. Graphs of PCM speed/brake/accel pedal data versus time showing VBOX speed and the cosine of the slip angle (where 1 = moving straight ahead and 0 = moving sideways) are presented.

The accuracy of the Powertrain Control Module (PCM) Event Data Recorder (EDR) was tested on a 2009 Ford Crown Victoria Police Interceptor during both straight line steady state conditions and maximum ABS braking, at the Michigan State Police training facility in Lansing, MI. Six runs were made starting from 64 km/h (40 mph) and six runs starting from 96km/h (60 mph). Data was collected from the PCM EDR and the primary speed reference instrumentation was a Racelogic VBOX III (with IMU) 100 Hz differential GPS speed data acquisition system. On selected runs Radar was used as additional steady state speed verification and for the braking portion a Vericom 3000 was used to verify speed loss and calculated stop distance. Visible ABS tire marks were documented following each test, and the length of marks was compared to the calculated braking distance from each measurement device. Graphs of PCM speed/brake/accel pedal data versus VBOX speed over time are presented.

The paper reports test results for accuracy of pre-crash speed, brake, and accelerator pedal position data recorded in a new family of Ford RCM EDR’s under steady state conditions. The authors drove 2 test vehicles at 3 different speeds from 48 to 113 km/h (30 to 70 mph), and artificially created EDR events so pre-crash data would be stored. The authors collected RCM data and PCM data. A GPS based Racelogic VBOX was used to measure speed and record CAN bus information real time. Maximum error, average error, and 98% confidence intervals are reported for RCM to VBOX and PCM to VBOX. Accelerator pedal position accuracy and brake on/off reporting latency of the RCM to CAN bus data and/or auxiliary brake switches are documented.

This paper reports test results for accuracy of pre-crash speed, brake, and accelerator pedal data recorded in selected 2008 model year Chrysler ACM EDR’s under steady state speed conditions. The authors drove two test vehicles at two different speeds, 56 and 113 km/h (35 and 70 mph), and artificially created EDR events so pre-crash events would be stored. The authors collected ACM EDR data after each run. A differential Global Positioning System (GPS) based Racelogic VBOX III (100Hz) was used to measure vehicle speed and record brake on/off and accelerator pedal voltage real time. Maximum error, average error, and 98% confidence intervals are reported for EDR to VBOX. Accelerator pedal position accuracy and brake on/off reporting latency versus auxiliary sensor taps are documented.

The primary purpose of this paper is to evaluate the accuracy of speed data recorded in the Ford PCM under steady state conditions. The authors drove 3 different test vehicles at 5 different steady state speeds from 48 to 113 kph (30 to 70 mph), making 6 runs at each speed. The authors collected PCM data after each run. For the first vehicle a GPS based Racelogic VBOX III was used to measure speed. For the second and third vehicle a purpose built speed trap with .0001 second resolution was used. The authors compare the readings and calculated differences and statistical limits. The secondary purpose is to deliberately create conditions that could result in errors of speed measured, document the conditions, and to quantify the error.