Four Wheel Steering Control System
2009.6.10 (Wed)
Pongsathorn Raksincharoensak, TUAT
Four Wheel Steering Control System
1
Vehicle Dynamics Control
Tokyo Univ. of Agriculture & Technology Mech. Sys. Eng. Nagai Laboratory
Enhancing vehicle dynamics performances by Active Chassis Control Technologies
Traction (driving)
Roles of Chassis Control
Respect to the driver intention
Cornering
Cornering
Reduce the driver workload Enhance its limit performance avoiding side-slip, spin,etc during emergency maneuver
Braking
Pongsathorn Raksincharoensak, TUAT
Four Wheel Steering Control System
2
Active Safety Technology
Tokyo Univ. of Agriculture & Technology Mech. Sys. Eng. Nagai Laboratory
Active Safety Technology is realized by active chassis control systems for enhancing Vehicle Dynamic Performance, as follows; ・ABS : Anti-skid Brake System ・TCS : Traction Control System ・4WS : Four-Wheel-Steering, (Active Rear Steer) ・AFS : Active Front Steer, (Steer-by-Wire, EPS) ・DYC : Direct Yaw-moment Control, (VSC, ESP)
Pongsathorn Raksincharoensak, TUAT
Four Wheel Steering Control System
3
Driver-vehicle system
Road
DRIVER
Recognition Decision Operation
Input
VEHICLE
Output
The relationship of input-output in the driver-vehicle-controller system
CONTROLLER
Road
DRIVER
VEHICLE
Pongsathorn Raksincharoensak, TUAT
Four Wheel Steering Control System
4
Vehicle Chassis Control
(1) Active Rear Steer
sideslip motion control
Tokyo Univ. of Agriculture & Technology Dept. of Mech. Sys. Eng. NAGAI Lab.
Active Chassis Control (Planar motion) ・Yaw motion ・Sideslip motion
(2) Direct Yaw Control
(3) Active Front Steer
Pongsathorn Raksincharoensak, TUAT
sideslip motion control(emergency) System Four Wheel Steering Control
yaw rate control
5
Four-Wheel-Steering System (4WS) Active Rear Steer System (ARS)
y
γ
V
β
x
Lr
Pongsathorn Raksincharoensak, TUAT Four Wheel Steering Control System
Lf
6
Equivalent Bicycle Model (Vehicle-Fixed Coordinate)
y