Slip Setup

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Target Switch

 

setup1-targetswitch

 

Different percentage target slip values can be assigned for each position of the target slip switch.  The first position is always off, and then it is recommended that the target slip percentages increase as the switch is rotated.  There are two values - one used while the vehicle is traveling in a straight line, and another when cornering.  Generally the cornering target slip needs be lower than the straight line slip, as the tires will not accept as much longitudinal slip if there is a lateral (cornering) force on the tire.  See Setup 2 for how cornering is determined.

 

Cornering

When cornering the tires will not accept as much longitudinal slip if there is a lateral (cornering) force on the tire. Cornering can be determined by comparing the wheel speeds on the left of the vehicle with the wheel speeds on the right of the vehicle.

 

setup2-cornering

 

Method is which wheel speeds to compare to determine if the vehicle is cornering.  Left / right speed difference (recommended setting) uses all four wheels, front uses the two front wheels and rear uses only the rear wheels.

 

Minimum speed difference is the minimum speed difference between the left and right wheels before the vehicle is determined to be cornering. It is recommended to use 2 kph.

 

Minimum cornering time is the minimum amount of time the wheel speeds need to be different by the minimum speed difference amount before the vehicle is determined to be cornering.  It is recommended to use 50-200 ms.

 

Launch Compensation

When first moving from a stationary position ('launching') with enough power to spin the wheels, the driven wheels will move before the un-driven wheels.  This results in a very high slip rate and the traction control will try to reduce engine power to meet the target slip.

To fine tune to amount of wheelspin when launching, a launch compensation table is used to set the target driven to un-driven wheel speeds in order to allow wheelspin. Before the front to rear slip ratio is calculated the driven wheel speed is reduced by the difference between the vehicle speed (un-driven wheel speed, bottom row of the table) and the driven wheel target speed (top row of the table).

Launch-Comp

In the above example, the traction control will initially allow the front wheels to reach 40 mph, then will reduce the front wheel speed to 30 mph, and finally once the vehicle speed reaches the same as the front wheels (at 30 mph vehicle speed) normal traction control operation resumes.

To disable launch compensation set the top row to the same as the bottom row or enter all zeros.

 

Cornering Slip Compensation

When turning a corner, all four wheels travel at different speeds. This will result in a false slip reading unless compensated. The actual wheel speeds when cornering depend on the radius of the corner, vehicle wheelbase, vehicle front and rear track width and the axle speed determination.

 

setup2-cornering-comp

 

It is recommended to use the Calc button to set the values based of common vehicle settings.