"Computer based wireless automobile wheel alignment system using accelerometer” scientific paper, as published at “The International Journal of Engineering and Science (IJES)”, Volume 4, 2015 by Sonali Chatur

1. COMPUTER BASED WIRELESS
AUTOMOBILE WHEEL
ALIGNMENT SYSTEM USING
ACCELEROMETER
Omer Mohammed Omer 125067

2. Wheel alignment, sometimes referred to as breaking
or tracking, is part of standard automobile
maintenance that consists of adjusting the angles of
wheels so that they are parallel to each other and
perpendicular to the ground
In order to study the wireless wheel alignment system a
basic understanding of the regular wheel alignment system
should be built up

3. INFLUENCING
PARAMETERS IN WHEEL
ALIGNMENT:
Caster:
If viewed from the side of the vehicle,
caster is an imaginary line drawn between
the centers of the upper and lower ball
joints which forms an angle with true
vertical, Caster is important to steering
feel and high-speed stability

4. INFLUENCING
PARAMETERS IN WHEEL
ALIGNMENT:
Camber:
If viewed from the front of the vehicle,
camber describes the inward or outward
tilt of the tire.
Camber adjustment maximizes the tire-to-
road contact and takes into account the
changes of force when a vehicle is turning.
Camber should be set to manufacturer’s
specification according to steering
geometry.

5. INFLUENCING
PARAMETERS IN WHEEL
ALIGNMENT:
Toe:
if viewed from the front of the
vehicle, toe describes whether the
fronts of the tyres are closer (toe-in)
of farther apart (toe-out) than the
rears of the tyres. Toe is set so that
the tyres roll in parallel when your
vehicle is in motion.

6. FORCES AFFECTING
WHEELS:
There are several forces, moments
and angles that prove to be very
important in tire behavior. All
these forces can be seen as the
forces and moments acting on the
tire from the road

7. MATHEMATICAL MODEL
FOR CAMBER ANGLE & TOE
CALCULATION
The values of θ and Ф can be obtained
as follow:

8. DESIGN OF WIRELESS
WHEEL ALIGNMENT
UNIT:
1. Sensing Unit
2. Processing Unit
3. Trans-Receiver Unit
4. Display Unit

9. SENSING UNIT:
The ADXL335B accelerometer gives an output as
voltage representing the three values of acceleration
in (X, Y, Z) which are proportional to the values of
alignment angel.

10. PROCESSING UNIT:
Arduino with built-in Microcontroller ATME328 is
used thus it satisfies selection criterion. Output
voltage of ADXL335 accelerometer is applied to the
analog inputs A0-A2 of Arduino.

11. TRANS-RECEIVER UNIT:
Available information signal from Arduino is
transmitted using (CC250 + PIC F1824
Microcontroller) platform, which is widely available
and use for wireless communications techniques

12. RECEIVER SECTION:
At the receiver side the signal is fed to serial to USB
converter. Available signal is concatenated so x, y and z
parameters needs to separate so logic is developed
and all the three signals and concatenated string is
displayed in text boxes as well. Retrieved signal is
mathematically processed to obtain phase i.e. angles in
degree