Traction ControlOutlineTraction Control MethodsAutomobile SpecificsOur FocusOur Focus IICalculation of Estimated Yaw RateEstimated Yaw Rate ResultsYaw CorrectionBreak PressureSlide 11Questions?Traction ControlTraction ControlMichael BoersmaMichael LaGrand12/10/03OutlineOutlineMethods for traction control Method studiedResultsQuestionsTraction Control MethodsTraction Control MethodsControl of power to wheelsControl of breaksFactors used for control–Velocity–Yaw rate–Automobile specific variablesAutomobile SpecificsAutomobile SpecificsWheel trackWheel baseCenter of gravityDistance from center of gravity to axisTire stiffnessOur FocusOur FocusControlling stability using the breaksInput factors–Vehicle velocity and angular velocity of the wheels–Driven wheel angle–Assumed vehicle constantsOur Focus IIOur Focus IICalculated results–Estimated yaw rate–Correction factor–Desired yaw rate–Break pressure to be appliedMatLAB (in progress)Calculation of Estimated Yaw Calculation of Estimated Yaw RateRateUse velocity to find angular velocity of wheelsUse curve radius to find driven wheel angleUse angular velocity and wheel angle to find yaw rateEstimated Yaw Rate ResultsEstimated Yaw Rate ResultsGraph of Yaw Rate vs. Curve RadiusFor velocities of 15, 25 and 35 MPHYaw CorrectionYaw CorrectionAs the velocities become large the error in estimating the yaw rate also becomes largerA correction factor is calculated using the desired yaw rate and lateral accelerationBreak PressureBreak PressureThis is the break pressure applied to the wheels to keep the yaw rate in checkFound using a gain factor and the difference between the estimated yaw rate and correction factorGain factor depends of brakes (unity in our case)Break PressureBreak PressureBreak Pressure vs. Curve RadiusFor velocity of 15
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