/// <summary>
/// the suspension of a single wheel
/// </summary>
/// <param name="wheel">the wheel for which the suspension is</param>
public WheelSuspension(ImportantClasses.Enums.Wheels wheel)
{
BellCrank = new BellCrank();
Damper = new Damper();
PushRod = new PushRod();
WheelHub = new WheelHub();
Wishbone = new Wishbone();
Wheel = wheel;
_actualCalculation = new SuspensionOutput();
}
/// <summary>
/// calculates a single wheel
/// </summary>
public void Calculate()
{
SuspensionOutput suspensionCalculation = SuspensionOutput.GetLastCalculation(_wheel); //get the outputs of the suspension for this wheel
//calculates the half width of the car, so that it is not needed to calculate a couple of times
float halfTrackWidth = CalculationController.Instance.OverallCar.TrackWidth / 2;
//force = torque/radius of a wheel
_actualCalculation.LongitudinalAccelerationForce = suspensionCalculation.AccelerationTorque /
(CalculationController.Instance.Wheels.Diameter / 2);
if ((int)_wheel < 2) //front axis
{
_actualCalculation.LongitudinalDecelerationForce = BrakeOutput.LastCalculation.BrakeMomentFront / 2;
}
else //rear axis
{
_actualCalculation.LongitudinalDecelerationForce = BrakeOutput.LastCalculation.BrakeMomentRear / 2;
}
//calculate the drivingRadius and the lateral acceleration
float drivingRadius; //the radius which the wheel will take in a curve
if (suspensionCalculation.WheelAngle < 0) //drive right
{
drivingRadius = ((int)_wheel < 2
? SteeringOutput.LastCalculation.RadiusFrontAxis
: SteeringOutput.LastCalculation.RadiusRearAxis) +
(((int)_wheel) % 2 == 0 ? halfTrackWidth : -halfTrackWidth);
_actualCalculation.LateralAcceleration = OverallCarOutput.LastCalculation.Speed *
OverallCarOutput.LastCalculation.Speed / drivingRadius;
}
else if (suspensionCalculation.WheelAngle > 0) //drive left
{
drivingRadius = ((int)_wheel < 2
? SteeringOutput.LastCalculation.RadiusFrontAxis
: SteeringOutput.LastCalculation.RadiusRearAxis) +
(((int)_wheel) % 2 == 0 ? -halfTrackWidth : halfTrackWidth);
_actualCalculation.LateralAcceleration = -OverallCarOutput.LastCalculation.Speed *
OverallCarOutput.LastCalculation.Speed / drivingRadius;
}
else //drive straight ahead
{
_actualCalculation.LateralAcceleration = 0;
}
//calculate the direction in which the wheel would like to drive
_actualCalculation.Direction = ((Vector2)OverallCarOutput.LastCalculation.Direction).Rotate(suspensionCalculation.WheelAngle);
_actualCalculation.Slip = 0; //actually the calculation is not ready; the slip is allways zero and the maximum force is infinity
if (OnCalculationReady != null)
{
OnCalculationReady();
}
}
public void TestSuspension()
{
_suspension.Calculate();
_suspension.StoreResult();
Assert.AreEqual(SuspensionOutput.GetLastCalculation(Wheels.FrontLeft).AccelerationTorque, 0);
Assert.AreEqual(SuspensionOutput.GetLastCalculation(Wheels.FrontLeft).WheelAngle, Math.PI / 4, 1e-5);
Assert.AreEqual(SuspensionOutput.GetLastCalculation(Wheels.FrontLeft).WheelLoad, 50 * 9.81f, 1e-5);
Assert.AreEqual(SuspensionOutput.GetLastCalculation(Wheels.FrontRight).AccelerationTorque, 0);
Assert.AreEqual(SuspensionOutput.GetLastCalculation(Wheels.FrontRight).WheelAngle, Math.PI / 5, 1e-5);
Assert.AreEqual(SuspensionOutput.GetLastCalculation(Wheels.FrontRight).WheelLoad, 50 * 9.81f, 1e-5);
Assert.AreEqual(SuspensionOutput.GetLastCalculation(Wheels.RearLeft).AccelerationTorque, 50);
Assert.AreEqual(SuspensionOutput.GetLastCalculation(Wheels.RearLeft).WheelAngle, 0, 1e-5);
Assert.AreEqual(SuspensionOutput.GetLastCalculation(Wheels.RearLeft).WheelLoad, 50 * 9.81f, 1e-5);
Assert.AreEqual(SuspensionOutput.GetLastCalculation(Wheels.RearRight).AccelerationTorque, 50);
Assert.AreEqual(SuspensionOutput.GetLastCalculation(Wheels.RearRight).WheelAngle, 0, 1e-5);
Assert.AreEqual(SuspensionOutput.GetLastCalculation(Wheels.RearRight).WheelLoad, 50 * 9.81f, 1e-5);
}
public void Init()
{
_wheels = new Wheels();
SuspensionOutput sout0 = new SuspensionOutput();
sout0.AccelerationTorque = 0;
sout0.WheelAngle = (float)Math.PI / 4;
sout0.WheelLoad = 50 * 9.81f;
SuspensionOutput sout1 = new SuspensionOutput();
sout1.AccelerationTorque = 0;
sout1.WheelAngle = (float)Math.PI / 5;
sout1.WheelLoad = 50 * 9.81f;
SuspensionOutput sout2 = new SuspensionOutput();
sout2.AccelerationTorque = 50;
sout2.WheelAngle = 0;
sout2.WheelLoad = 50 * 9.81f;
SuspensionOutput sout3 = new SuspensionOutput();
sout3.AccelerationTorque = 50;
sout3.WheelAngle = 0;
sout3.WheelLoad = 50 * 9.81f;
SuspensionOutput.LastCalculations[0] = sout0;
SuspensionOutput.LastCalculations[1] = sout1;
SuspensionOutput.LastCalculations[2] = sout2;
SuspensionOutput.LastCalculations[3] = sout3;
SteeringOutput.LastCalculation.RadiusFrontAxis = 10;
SteeringOutput.LastCalculation.RadiusRearAxis = 10;
CalculationController.Instance.Wheels.Diameter = 0.5f;
CalculationController.Instance.OverallCar.TrackWidth = 1.5f;
CalculationController.Initialize(1);
BrakeOutput.LastCalculation.BrakeMomentFront = 10;
BrakeOutput.LastCalculation.BrakeMomentRear = 10;
OverallCarOutput.LastCalculation.Speed = 10;
OverallCarOutput.LastCalculation.Direction = new Vector3(1, 0, 0);
}
/// <summary>
/// stores the calculation results to the SuspensionOutput class
/// </summary>
public void StoreResult()
{
SuspensionOutput.SetLastCalculation(Wheel, _actualCalculation);
}
