AP

Prepared by: Abdullah F. F. Shehadeh Abd-Errazzaq Shehadeh

Hardware Graduation Project2010 - 2011

Auto-Parking (Autonomous Parallel Parking Car)

Parallel parking is one of the most complex

driving scenarios. AP is system that enables cars to parallel park autonomously.

The car starts by measuring the slots between parked cars until it finds a slot that fits it. The minimum slot required for the car to park in is twice the car length.

If the slot is insufficient, the car continue searching for a suitable one.

Once the car finds a suitable slot it enters the parallel parking mode. By the end of this mode, the car will be parked.

AP

PIC 18F4550: USB Microcontroller. SHARP IR sensors (GP2Y0A21YK): three

sensors (10-80cm). H-Bridge (L298N). 5-V, 9-V voltage regulators (7805, 7809). Car model. Two 3.7 rechargeable batteries. PC power supply. PCB: Printed Circuit Board.

Devices Used:

Ultrasonic Sensors: we avoid their usage

because of the nature of ultrasonic waves (not directed) that causes many reflections.

IR Sensors: we chose this type because of its simplicity and it covers the ranges we need. We used three (10 – 80 cm) sensors. A longer range exists (up to 1.5 m) can be used when applying the system to real cases.

Distance Sensors Types:

Original Car

Car with our circuit

Our Circuit

H-bridge & Heat-Sink

Sensors Output

Sensors Noise Elimination

Sensors Direction

It is preferred to position the sensor such that it is orthogonal with respect to the motion direction.

PCB Schematic

PCB Board

We have derived an equation that describes

the car motion in auto-parking mode:

Mathematical Model

)1(*

**

*

r

ts

rts

rArcLength

According to sine rule:

Mathematical Model

)2(*)2

sin(*2

*)2

cos(

)2

cos(*)2

sin(*2

*)2

cos(

sin

*)2

90sin(

sin

*)

2180

sin(

sin

)2

180sin(sin

rh

rh

rh

rh

rh

rh

By substituting (1) in (2):

The last equation describes the motion of the car.

Mathematical Model

*)*2

*(sin**4

*)*2

*sin(*2

*)*2

*sin(*2

222

22

2

hdr

tsrvd

hdrr

tsvd

rr

tsh

By substituting the values of r and s:

Using MS Excel, we have solved this equation for many values:

Mathematical Model

222 )*48.0(sin*81.0 hdtvd

PCB: It is our first project using printed

circuits. We have learned how to work on Eagle program and we have faced many problems making the appropriate routing.

PIC 18F4550: It is a USB microcontroller that requires the use of special bootloaders and programs like MPLAB. We faced many problems in defining it on Windows 7.

Problems we faced!

Mechanical problems: we changed the car

model twice, in order to use a small car that can be driven using batteries, but finally we were obliged to use power supply in order to supply the motors with the required current. Another mechanical problem is the rotation angle of the front motor which is much smaller than the real case, what results in the need of doing the parking on many stages.

Problems we faced!

Thanks a lot for your listening

Best Regards