In order to detect harsh acceleration, braking, and cornering events, the accelerometer must run continuously so that it can auto-orientate (figure out why way is down — as gravity impacts the forces seen) itself and additionally self-calibrate.
Given the power draw of the accelerometer, this is impractical to implement on a battery-powered device — so it is limited to the powered device range. These devices can be configured to send alerts when harsh events, accidents, or vehicle rollovers are detected. If vehicle rollover alerts are required, a powered device should be selected for the application.
- Driver behavior monitoring
- Safety and compliance
- Fleet management
High-G event detection
This feature is designed around detecting where and when an impact has occurred to a device in transit. This will help in determining where damage may have been sustained. When enabled, this feature draws slightly more battery than if disabled. It will simply log a record (and upload if configured) any events that exceed a set force threshold. The minimum threshold is 1.5G and maximum is 6G (along any axis).
- Asset abuse or misuse monitoring
The Tip Detection feature allows you to define a range of angles that constitute a ‘tipped’ state. Every time the device enters this range, it will set a digital input, and increment an analog counter. It can also optionally log a record, perform a GPS fix, upload data, or scan for Bluetooth tags.
- Detecting emptying of containers like skip bins
- Tamper detection — when the angle changes the device may have been removed from an asset
- Detecting if the equipment has been knocked over.
This feature is not suitable for detecting a vehicle rollover, for a few reasons:
- It has no auto-orientation function, so must be installed in the correct orientation to function.
- It only supports a single roll axis — so rollover can easily be missed.
- Enabling this feature uses extra power while the device is on the move, for the duration of movement, which will result in potentially unsatisfactory battery life on a constantly moving vehicle.
This feature keeps a count of the number of rotations of the device about the Z axis.
- Detecting the uncoiling of cable drums.
This feature is available on the Guppy LoRaWAN — and will trigger an uplink once a pre-defined threshold.
- Detecting when signs, fence posts, etc. have fallen over.
Most of the devices by the Digital Matter are fitted with a 3D accelerometer, which is used to provide a variety of features. Many of the features are quite similar, but they have key differences that make them suitable for certain applications, and less suitable for others.
Features per device