ackerman steering geometry and cornering
- 2. STEADY STATE HANDLING CHARACTERISTICS HOW TO HANDLE THE VEHICLE….? • Ackermann Steering Geometry
- 3. ACKERMANN STEERING GEOMETRY • Ackermann steering geometry is a geometric arrangement of linkages in the steering of a car or other vehicle designed to solve the problem of wheels on the inside and outside of a turn needing to trace out circles of different radii. • The use of such geometry helps reduce tyre temperatures during high-speed cornering but compromises performance in low speed . • The intention of Ackermann geometry is to avoid the need for tyre to slip sideways when following the path around a curve.
- 4. • As the rear wheels are fixed, this centre point must be on a line extended from the rear axle • Intersecting the axes of the front wheels on this line as well requires that the inside front wheel is turned, when steering, through a greater angle than the outside wheel .
- 5. Where t = tread L = wheel base 𝛿o= steer angle of the outside wheel in a turn 𝛿I = steer angle of the inside wheel in a turn R = Radius of turn
- 8. High Speed Cornering • High speed cornering produces different equations with respect to low speed cornering. • Tires must develop significant lateral forces to counteract the lateral acceleration. • Slip angles will be present at each wheel
- 9. Tire Cornering Forces • Under cornering conditions,in which the tire must develop a lateral forces, the tire will also experience lateral slips as it rolls. • The angle between the direction of heading and its direction of travel is called slip angle. • Below about 5˚ slip relationship is linear Where ; Cα — cornering stiffness