The document discusses various chassis control systems, including brake control systems like ABS and traction control, steering systems like electric power steering, suspension systems like active and adaptive suspensions, and assistance systems like lane assist, park assist, and adaptive cruise control. It provides details on the purpose, components, and control systems of each.

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Mtech ARAI Academy
Chassis Control Systems:
The chassis control system can be classified as
 Brake control system
 Steering control system
 Suspension(Ride) control system
 Supervision Control Systems
 Assistance Control system

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Mtech ARAI Academy
BRAKE CONTROL SYSTEM:
1. ABS-Antilock Braking system: Anti-lock braking systems (ABS) are active safety
features designed to help drivers retain steering control by preventing wheels from
locking up during an episode of heavy braking. ABS system calculates slip ratio based
on the speed of the vehicle and the wheel. That slip ratio is used to calculate the
braking pressure required to avoid the wheel lock.
Sensor inputs:
 Wheel speed sensor
 Vehicle speed sensor
 Brake lever position sensor
The parameters that affect ABS system are:
 Drive torque
 Wheel Mass
 Gravity(g)
 Wheel radius
 Moment of inertia

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Mtech ARAI Academy
 Braking torque
2. Traction control system: is typically a secondary function of the anti-lock braking
system. TCS is activated when throttle input and engine torque are mismatched to
road surface conditions causing wheel slip, designed to prevent loss of traction of
driven road wheels.
Intervention consists of one or more of the following:
 Brake force applied to one or more wheels
 Reduction or suppression of spark sequence to one or more cylinders
 Reduction of fuel supply to one or more cylinders
 Closing the throttle, if the vehicle is fitted with drive by wire throttle
 In turbocharger vehicles, a boost control solenoid is actuated to reduce boost and
therefore engine power.

4. Traction Control also uses slip ratios to determine the slipping of wheels by comparing
the speed of the vehicle and the wheels. The sensors are same as ABS usually TCS
system comes as an advanced feature of ABS not much hardware changes are required
for TCS if ABS is already there.
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Mtech ARAI Academy
3. Electronic Stability Program:
This is an active safety technology that improves the stability of the vehicle by detecting
and reducing loss of the traction, brakes are applied when Electronic stability program
detects a loss of steering control. The loss of the steering control can be due to Under-steering
or Over-steering during cornering. The ESP ECU controls against over-steering
or under-steering during cornering by controlling the vehicle stability using the input
values from the sensors and applying the brakes independently to the corresponding
wheels. The system also limits the engine output by limiting the throttle.
Sensor Inputs:
 Steering wheel angle sensor
 Yaw rare sensor

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Mtech ARAI Academy
 Lateral acceleration sensor
 Wheel speed sensor
 Longitudinal acceleration sensor
Control system Diagram
These equations are used to calculate the desired values for vehicle side slip and vehicle
and vehicle yaw velocity.
ESP during Under steering:
Under steering is when the steering wheel is steered to a certain angle during the
front tires slip towards the reverse direction of the desired direction. The ESP system
recognizes the directional angle with the steering wheel angle sensor and the slipping
route that occurs reversely against the vehicle cornering direction during under-steering
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.

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Mtech ARAI Academy
ESP during Over steering:
Oversteering is when the wheel is steered to a certain angle during driving and the
rear tires slip outward losing traction. ESP system recognizes the directional angle with
the steering angle sensor and senses the slipping route that occurs towards the vehicle
cornering direction during over steering with the yaw rate sensor and the lateral sensor.
Then the ESP brakes at the front outer wheel to compensate the yaw moment value.
STEERING:
 Electric Power steering

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Mtech ARAI Academy
Sensors Used:
o Torque sensor
o Angle Sensor
o Speed Sensor
Actuator Used :
o Dc Motor.
Control System:

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Mtech ARAI Academy
SUSPENSION SYSTEMS:
Adaptive suspension/semi-active suspension:
The active suspension and adaptive suspension/semi-active
suspension are types of automotive suspensions that control the vertical
movement of the wheels with an onboard system, rather than in passive
suspensions where the movement is being determined entirely by the road
surface. Active suspensions can be generally divided into two main classes:
pure active suspensions and adaptive/semi-active suspensions
Active suspension control system:

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Mtech ARAI Academy
Sensors used:
 Wheel Speed sensor
 Body sensors(accelerometer)
 Yaw rate sensors.
ASSISTANCE SYSTEMS:
 Lane Assist
 Park Assist
 Adaptive Cruise Control System
Lane Assist:
Lane Assist/lane departure warning system is a mechanism designed to warn a driver when the
vehicle begins to move out of its lane.
Control System:
Park Assist:

10. The technology assists drivers in parking their vehicle On vehicles equipped with the Park Assist
system, via an in-dash screen and button controls, the car can steer itself into a parking space with
little input from the user
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Mtech ARAI Academy
Control System:

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Mtech ARAI Academy

12. Adaptive cruise control (ACC) is an intelligent form of cruise control that slows down and speeds
up automatically to keep pace with the car in front of you. The driver sets the maximum speed —
just as with cruise control — then a radar sensor watches for traffic ahead, locks on to the car in a
lane, and instructs the car to stay 2, 3, or 4 seconds behind the person car ahead of it (the driver
sets the follow distance, within reason). ACC is now almost always paired with a pre-crash system
that alerts you and often begins braking.
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Adaptive cruise control system:
Mtech ARAI Academy
RIDE:
 Tire Pressure sensor