NEXON

STEERING

1.1.3. GENERAL DESCRIPTION

The

EPAS

(

lectrical

ower

ssisted

teering -

column mounted) is made up of the following

components

The system consists of the steering column and a

servo unit. The steering torque is transmitted via

the intermediate shaft with universal joints to the

mechanical rack and pinion steering. Sensor

technology and torsion bar are next to the helical

gear drive in the servo unit. The helical gear drive

converts the support torque generated by the servo

motor and transmits it to the intermediate shaft.

The support torque and operating torque of the

steering wheel generated are transmitted via the

intermediate shaft to the mechanical rack-and-

pinion steering gear and then to the front wheels.

If the vehicle power supply or electrical supply fails,

then the vehicle can still be steered due to the

mechanical connection between the steering

wheel and front tires being steered.

EPAS system is equipped with following assist

feature

1. Speed Sensitive Assist Control

2. Active Return Control

FUNCTION

The torque sensor in servo unit registers the

steering torque and steering speed once the driver

performs a steering motion.

All data (including the vehicle signals such as

engine speed, vehicle speed, ignition signal) is

transmitted to the control unit (ECU). This then

calculates the necessary support torque and on the

basis of the calculated results, controls the servo

motor.

A rotor position sensor is attached to the servo

motor. An index sensor is integrated in the torque

sensor.

The control unit uses the integrated index sensor

and the rotor position sensor to calculate the

steering wheel’s steering angle.

Depending on the programming, the steering

wheel’s angle signal can be sent back to the

vehicle.

BLOCK DIAGRAM OF EPAS SYSTEM