Link G4X Fury, Xtreme and Plugin ECUs have a built in accelerometer. This sensor used is a precision calibrated 3 axis accelerometer capable of measuring acceleration in any direction. This can be used to measure, log and display the acceleration forces applied to the ECU (and hence the vehicle it is attached to). The accelerometer requires no calibration to accurately measure force but as the ECU can be installed in the vehicle in any orientation the accelerometer must be corrected so it knows where level is and also so it knows where the front of the car is.
Settings
Instructs the ECU to apply a correction to the accelerometer measurements to correct for the mounting orientation of the ECU. This test must be performed with the car sitting on level ground. The purpose of this test is to tell the accelerometer exactly what position is level.
·Run - Use current measurements.
·Zero Accelerometer - Correct for ECU orientation. This mode automatically sets itself back to Run once it has performed the calibration
After using the Zero Accelerometer function to tell the accelerometer where level is, it also must be told which direction is the front of the car relative to the ECUs installed orientation (this number is degrees in the horizontal plane, for example a value of 90 will result in a value that was previously Longitudinal now being Lateral). The simplest way to determine this setting is:
1.With the vehicle on level ground and the suspension at normal ride height, set Zero Accelerometer to Zero Accelerometer, wait for it to set itself back to Run. The accelerometer will now know where level is but does not know which direction forwards driving will be. Vertical Acceleration should show 1g.
2.Drive the vehicle while logging Lateral Acceleration and Longitudinal Acceleration. On a dead straight piece of track, perform a firm controlled deceleration (eg from 80 to 20 kph). Pay particular attention to keeping the vehicle traveling straight during the deceleration.
3.Ideally during the deceleration only negative Longitudinal Acceleration should be measured. If significant Lateral Acceleration is measured then adjust Orientation Correction and repeat until deceleration only shows a negative Longitudinal Acceleration reading.
4.Once completely calibrated and orientated both Longitudinal Acceleration and Lateral Acceleration should read zero when traveling at a constant speed. When braking and accelerating (straight) should not significantly affect Lateral Acceleration. Constant speed left or right cornering should not affect Longitudinal Acceleration.
Adjusts the amount of filtering applied to the accelerometer measurements. Increase the filtering to reduce the influence of vibration in the accelerometer signals. A larger number will be required in vehicles that experience high vibration (eg rally cars). A smaller number can be used in smooth riding vehicles (eg road cars).
Runtime Values
The acceleration measured lengthways along the vehicle. This gives an indication of acceleration and braking forces. The value displayed is in g-force.
The acceleration measured sideways across the vehicle. This gives an indication of cornering forces. The value displayed is in g-force.
The acceleration measured in the direction of gravity. This gives an indication of the downwards force applied on the tires. The value displayed is in g-force.