4. Esp control module

This unit has the functions as follows.

- Input of signal from Pressure sensor, Steering angle sensor, Yaw & Lateral G sensor, Wheel speed sensors The signal produced by the sensors are evaluated in the electronic control unit. From the information received, the control unit must first compute the following variables:

- Control of braking force / traction force/ yaw moment

- Failsafe function

- Self diagnosis function

- Interface with the external diagnosis tester

SPECIFICATION

• OPERATING VOLTAGE RANGE : DC 10 ~ 16V

• OPERATING TEMPERATURE RANGE : -40 ~ 110℃

• CONSUMPTION CURRENT a. BAT 1 Max: 30A(ABS/TCS) , 40A(ESP) b. BAT 2 Max: 30A

• DARK CURRENT: Max. 1.0mA

• IGN RATED CURRENT: Max. 300mA

A : INLET VALVE (FR)

B : INLET VALVE (RL)

C : INLET VALVE (RR)

D : INLET VALVE (FL)

E : OUTLET VALVE (FR)

F : OUTLET VALVE (RL)

G : OUTLET VALVE (RR)

H : OUTLET VALVE (FL)

I : ELECTRIC SHUTTLE VALVE (ESV-R)

J: ELECTRIC SHUTTLE VALVE (ESV-L)

K:TRACTION VALVE(TCR)

L: TRACTION VALVE(TCL)

M: MOTOR(+)

N: MOTOR(GND)

[ESPCM]

[TCSCM]

BASIC FUNCTIONS OF ESP

WHAT TRIGGERS AN ESP INTERVENTION

A criterion for ESP intervention exists when the yaw rate sensor senses an oversteering or understeering tendency of at least 4°/s (threshold depends on speed). If the plausibility analysis shows the same situation, action is taken to stabilize the driving condition.

In the event of oversteering

Braking intervention takes place at the wheels on the outside of the bend. Most of the braking force is introduced via the front wheel, which is caused to slip up to 50% so that the centrifugal force contributes to stabilizing the vehicle. In this case, the ABS logic is blotted out by ESP for the wheels with ESP intervention.

If over-steering begins to start while turning, vehicle moves far inward. Then, over-steering control activates. When the braking force is applied to outer wheels, yaw moment in opposite direction is generated to compensate the over-steer. Therefore, vehicle moves as the driver intends.

In the event of understeering

Braking intervention takes place at the wheels on the inside of the bend. In this case, the greater force is introduced via the rear wheel so that the lateral force is selectively reduced in exact does to stabilize the vehicle. The ABS logic is again blotted out by ESP for the wheels with ESP intervention.

When under-steering begins while the vehicle turning, vehicle slips outward regardless of driver’s intention. Then, under-steering control starts. The control module generates the braking force at the inner wheel of the vehicle and yaw moment generates, in which vehicle tries to turn to inner side of the road. Then, vehicle moves as the driver intends.