Three-axis electronic collision sensor for airborne application

This paper discusses the design and implementation of a low cost three-axis electronic collision sensor for airborne application. The primary function of collision sensor is to continuously monitor the flying situation of air vehicle, and to engage the ELT system in the case of crash accident occurs. The core component of the collision sensor is the MEMS accelerometers. The data acquisition, reduction, and crash determination are accomplished using a low cost PIC microcontroller. The crash condition is determined based on vehicle acceleration and variation of velocity. A backup Li-ion battery is incorporated into the system to prevent power shut down. A drop test is also developed and performed to investigate the characteristics of impact accelerations.