Accelerometer

Overview

The KV8, KV12, KV16 ECUs have an internal 3-Axis Accelerometer. This can be used to measure:

  • Braking and acceleration g-force (longitudinal acceleration) 
  • Cornering g-force (lateral acceleration) 
  • Up/down g-force (vertical acceleration) 

Other features include:

  • 16 Bit Resolution
  • +2g/+4g/+8g dynamically selectable full-scale
  • Output Data Rate 500Hz

The digram below shows the orientation of each ECU axis.

Image Image

The digram below shows the orientation of each axis reference from the vehicle.

Image Image

The ECU allows each vehicle axis to be assigned to an ECU axis (X,Y,Z) .  For example the Longitudinal Axis can be assigned to the ECUs X or Y or Z axis. This allows the ECU to be mounted at any position/orientation within the car.

These settings are available from the Tuning view -> Vehicle Setup -> Accelerometer Setup Menu.

Typical Values:

Longitudinal positive g-force = Acceleration. Typical values 0.3 to 0.5g

Longitudinal negative g-force = Braking. Typical values: -1.5 to -1.8g

Lateral negative g-force = Turning Left. Typical value for race car on slicks : -1.8g

Lateral positive g-force = Turning Right. Typical value for race car on slicks : 1.8g

Accelerometer Full Range

This sets the maximum g-force that can be measured in any axis. There are 3 Full Range modes adjustable through EMtune. 

  • +2g
  • +4g
  • +8g

Normally 2g is enough for most racing applications where there is limited downforce. However, on applications with significant downforce such as under-body trays or large wings then the 4g or 8g option is recommended.