Longitudinal Compliance Test

LONGITUDINAL COMPLIANCE, BRAKING
The vehicle chassis is held fixed by the K&C rig center table while longitudinal forces are applied through each of the four tire contact patches. Vehicle brakes are applied. Forces are applied in the direction consistent with braking. Corresponding loads, displacements, and orientations are measured at each of the four wheels.

LONGITUDINAL COMPLIANCE, TRACTION
The vehicle chassis is held fixed by the K&C rig center table while longitudinal forces are applied at each tire contact. Vehicle brakes are not applied. A transmission or drivetrain lock is used on the driven axle(s) to transmit ground plane forces to the wheel centers while ground plane forces are applied through the tire contact patches. Force is applied in the direction consistent with vehicle forward acceleration. Corresponding loads, displacements, and orientations are measured at each of the four wheels.

LONGITUDINAL COMPLIANCE, SINGLE WHEEL
The vehicle chassis is again held fixed and longitudinal force is applied to wheels on one side of the vehicle only. This shows how force applied to one side affects the other side. It also simulates a worst case split mu surface condition.

Here are some characteristics that are measured in a Longitudinal Test:

  • W/C Stiffness
  • Toe Stiffness
  • Jacking Forces
  • Caster Stiffness
  • Camber Stiffness
  • Hysteresis
  • Force Anti-Dive Angle (Braking Test)
  • Force Anti-Squat Angle (Traction Test)