Esp Control; Understeering; Esp Controls During Under Steering - SSANGYONG 2004 Rexton 2.7XDi Workshop Manual

ESP CONTROL

The ESP system includes the ABS/EBD and ASR systems allowing the system to be able to operate depending to the
vehicle driving conditions. For example, when the brakes are applied during cornering at the speed of 100 km/h, the ABS
system will operate at the same time the ASR or ABD systems operate to reduce the power from the slipping wheel. And
when yaw rate sensor detects the rate exceeding 4¡Æ/seconds, the ESP system is activated to apply the brake force
to the corresponding wheel to compensate the yaw moment with the vehicle stability control function. When various
systems operate simultaneously under a certain situation, there may be vehicle control problems due to internal mal-
function of a system or simultaneous operations. In order to compensate to this problem, the ESP system sets the
priority among systems. The system operates in the order of TCS (ASR or ABD), ESP and ABS. The order may be
changed depending on the vehicle driving situations and driving conditions. As the single-track vehicle model used for
the calculations is only valid for a vehicle moving forward, ESP intervention never takes place during backup.

Understeering

Understeering
Understeering is when the steering wheel is steered to a certain angle during driving and the front tires slip toward the
reverse direction of the desired direction. Generally, vehicles are designed to have under steering. The vehicle can return
back to inside of cornering line when the steering wheel is steered toward the inside even when the vehicle front is
slipped outward. As the centrifugal force increases, the tires can easily lose the traction and the vehicle tends to slip
outward when the curve angle gets bigger and the speed increases.

ESP controls during under steering

The ESP system recognizes the directional angle with the steering wheel angle sensor and senses the slipping route
that occurs reversely against the vehicle cornering direction during understeering with the yaw rate sensor and the
lateral sensor. Then the ESP system applies the brake at the rear inner wheel to compensate the yaw moment value. In
this way, the vehicle does not lose its driving direction and the driver can steer the vehicle as driver intends.
ESP SYSTEM
REXTON SM - 2004.4
Without
ESP
Desired
course
Braked
wheel
Braking force
Compen-
sating yaw
moment
CHANGED BY
EFFECTIVE DATE
AFFECTED VIN
8E2-7
Y220_8E2003