Crash Test Data Recorder
DornerWorks produced an automotive crash recorder device that has several interesting aspects in all of our core embedded systems engineering disciplines: systems engineering, electronics hardware design, and FPGA and firmware design.
The data acquisition capability features 16 channels of EIA-485 data recording at 8 MHz, 4 channels of 10-bit analog data recording, and 24 10-bit DAC outputs. Data are buffered using 2 SRAMs with a 20-bit address and 8-bit data bus, and stored on 5 independent SPI flash devices. A High Speed USB 2.0 connection was used to pass data to a PC after the crash event, upon command by a custom-designed PC application.
Systems Engineering: The crash recorder is a mechanically durable solid-state recorder that is survivable up to 30 G of shock. DornerWorks performed the product development for the full product lifecycle, providing manufacturing oversight and project management on an aggressive schedule, requiring advance procurement of key long lead-time components. A flexible hardware and FPGA design allows add-on capability for future expansion of the recorder.
Electrical Engineering: Based on a TI Stellaris (ARM Cortex M3) MCU and an Altera Cyclone III FPGA, the recorder provides a USB 2.0 interface to download the recorded data from the device. The design has circuit protection on a typical 12V automotive power input for reverse voltage, overvoltage (up to 80 V), and overcurrent conditions, and provides power-hold capability through a crash event with energy storage capacity of 9000 joules.
FPGA and Firmware design: The data acquisition capability is implemented in the Altera FPGA, and system control and coordination is performed by the TI MCU.
- Flexible hardware and FPGA design allows add-on data acquisition capability
- Automotive power input
- 9000 joule energy storage capacity for power hold capability
- Lightweight, impact resistant enclosure, survives 30-g mechanical shock in 3 orthogonal axes
- Advance procurement of long-lead-time components
- Data download capability via LabVIEW-based application