When an impact / crash occurs, Munic.Box detects it and sends a notification to the server thanks to the Crash Detection module.
This chapter describes you how to configure the module parameters and how to integrate the notification in your back-end server.
Munic.Box detects the impact and crashes based on its internal accelerometer. By activating the Crash Detection module, Munic.Box is automatically configured with a 400 Hz accelerometer sampling for a more precise detection. Accelerometer data and GPS data are collected by Munic.Box in circular buffers. Then, when a threshold is detected during a short period of time, a crash event is triggered giving the maximum index of the of threshold detected. Finally, Munic.Box only sends the notification for crashes above a minimum crash force (minimum severity crash) described below:
A minimum crash severity defines the kind of crashes. Note that the range of the accelerometer and the minimum severity crash are related: if the range is configured to ±2g, then only the crashes up to 4000 mg are detected. Indeed, a range of ±2g detects a crash up to 4g.
With the Crash Detection module, Munic.Box sends a notification on a crash including:
The purpose of the Crash Detection module is only to detect crash. The crash data can be retrieved via the Crash Notification & Buffer module. Finally, none of these modules analyze the crash data: please see the Collision Cost Estimation apps.
When the module is linked with your Munic.Box, this service is not active by default: a configuration must be applied. The module must be configured with the following parameters:
|Module status||Activated or Deactivated||Deactivated|
|Range of the accelerometer||g||±2g|
|Minimum crash severity||Index||6|
Once a crash is detected, Munic.Box sends a notification to the server.
|MDI_CRASH_DETECTED||When a crash on the device is detected, this field is set to crash_id:severity||String||8|