4 THINGS YOU NEED TO KNOW
Accelerometers measure acceleration (often called ‘g’) along a single axis. It is measured in m/s2 (metres per second squared) and the average acceleration caused by gravity is 9.81m/ s2. Accelerometers in your IMU will read 0m/s2 in freefall, and 9.81m/s2 when stationary on the ground.
Roll and pitch can be approximated with accelerometers, but gyros are better as they aren’t affected by road bumps. But, small non-zero errors in gyro measurements mean angles calculated using gyro data can drift over time. By mixing gyros and accelerometers, this drift can be minimised.
3 Processing unit
Converting IMU data into chassis attitude is relatively easy in electronic terms, but the ECU already has other things to worry about, like injecting fuel and igniting it at the right time. It’s not unusual to off-load some of the processing to other components in complex systems. With extra processing capacity, it’s possible to combine IMU data with other measurements to produce better overall information on which to act.
It’s hard to check an IMU for failure because data is often output on to something called a CAN bus. The only way to tell if there’s a problem is to rely on the dashboard error messages, or to use a CAN bus sniffer to decode and inspect the IMU packets yourself. While this sounds like manufacturers being difficult, it does actually make sense as it’s cheaper, lighter and smaller than more conventional analogue/digital methods.
The system uses a modern electronic version of a giro
The IMU can be plugged into a computer to download data