1. Autonomous Chasing Robot (ACaR) an Autonomous Robotic Follower with License Plate Recognition Capability
Team 19:
Bryan Diaz BSEE
Victor Hernandez BSEE
Khanh Le BSEE
Luis Sosa BSCpE
Sponsored by___________

2. Description ACaR is a cost effective robotic platform with:
Autonomous Tracking and Following.
Autonomous License Plate Recognition (ALPR) capability.
Embedded Operating System.
The ACaR robotic system can potentially be used in law enforcement and military applications.
Law Enforcerment: such as high speed chasing
Military: Convoying/Caravaning

3. Motivations
Design a system which potentially could be used in practical applications.
Interested in Robotic Systems
Acquire Hands on experience in Real Time Computer Vision Applications
Real Time Object Tracking
Automated License Plate Recognition (ALPR)
Gain experience in design and integration of electrical systems
Motor(S)
Power system

4. ACaR: Specifications Title QTY Units Size 8 H x 18 L x 12 W in Weigh
3~4 kg
Voltage Range Operation
12 – 16.8 V
Battery Life
30+
minutes
Maximum Tracking Target Distance 5
feet
Minimum Tracking Target Distance 2
Maximum Following Speed
Up to 2
km/h
Simultaneous License Plates Detection
Up to 3
plates

5. High Level Diagram
take out ultra sonic SBC, MCU

6. Single Board Computer Raspberry Pi 2
Specs:
900MHz Quad-Core, ARM Cortex-A7 CPU
1GB RAM
4 USB Ports
Full HDMI port
Micro SD card slot
(Added) Heat Sinks and Fan
(Added) Modified Protective Case

7. Image Processing OpenCV
CMT algorithm (Consensus-based Matching and Tracking of Keypoints for Object Tracking)
Cascade Classifier Training (Implements Machine Learning)
opencv_traincascade (Haar and LBP)
Tell them that the system will be trained

8. License Plate Recognition (LPR)
Computer Vision
OpenCV
Image Processing
Leptonica Image Processing Library
Optical Character Recognition (OCR)
Tesseract OCR
Open Source
Open Source
Open Source
“Image Usage: Permission Granted under the terms of the GNU Free Documentation License”

9. LPR Process and Decision
“Permission Granted under the terms of the GNU Free Documentation License”

10. ALPR Testing Data Item Data Unit Min. Distance 1 foot Max. Distance 5
feet
Max. Angle 28
degrees
Max. Simultaneous 6
License plates

11. Software Block Diagram

12. Motor Control PWM is used to control the speed.
An H-bridge circuit is used to control
the direction of motor rotation.
The PWM signal is sent through pins 1 and 2. They are I/O pins of the MCU.

13. Pololu High Power Motor Driver
This discrete motor driver bases on the MOSFET H-bridge circuit.
This board can handle up to 30V of power supply.
Able to sustain continuous 15A without the heat sink.
This driver has its own circuit protection if short-circuit or overheat happen.
The table below shows the different operations of the Pololu Motor Driver.

14. Specification of Brushed DC Motor
Rated Voltage
12V
Rated Current
2.6A
Full Speed
20000 rpm
Shaft Diameter
3mm
Shaft Length
10mm
Body Diameter
36mm
Total Length
68mm
Weight
161g

15. Servo Control PPM signal is used to control position of Servo.
PPM uses 1 to 2 ms out of 20ms time period to encode the information
Mechanical steering system limitation:
Between 45 and 135 degree
Turning angle step is 5 degree.

16. Servo Connections
The Servo is connected to the MCU directly; no additional circuit is required for control
White Wire -> pin 10(P2.2) of Msp430
Red Wire -> Power supply (5V)
Black Wire -> Ground pin

17. Micro-controller for DC motor and Servo
Use MSP430G2553 chip as Micro-controller for motor control.
MSP430 will communicate with Pi through serial.
Pi sends instructions to MSP430 via wired serial communications.
MSP430G2553

18. MSP430 Connections Vcc (Pin1) 3.3V GND (Pin20) Ground Reset (Pin16)
RX/P1.1 (Pin3)
TX pin of Rasp Pi
P2.1 (Pin9)
DIR pin of Pololu
P2.5 (Pin13)
PWM pin of Pololu
P2.2 (Pin 10)
Servo Motor

19. Logic Level Shifter
It is used for interface between MSP430 and Pololu motor driver.
It receive 3.3V level signal from MSP430 and then shifting it up to 5V level before sending signal to Pololu.
Low Level
3.3V
High Level 5V A4
Pin9 of Msp430 B4
DIR pin of Pololu A6
Pin13 of Msp430 B6
PWM pin of Pololu
GND
Ground

20. Servo Motor (Steering)
Power System
Main DC Source
Voltage Regulator
(12 volts)
Motor
(5 volts)
Raspberry Pi
Camera
Servo Motor (Steering)
(3.3 volts)
MCU

21. Main DC Source (Rechargeable Battery)
Main Requirements
Battery life must be at least 30 minutes
Light weight (less than 1 pound)
Dimensions (7x3x2 inches)
Reasonable price (less than $50 dollars)
Battery Specifications
Battery Selected
14.8 Volts Lithium Polymer Ion Battery
Continuous Discharge
42 Amps
Energy Capacity
31.08 watt hour
Battery Life
1 hour
Charge Time
1 hour and 30 minutes
Weight
8.4 oz
Price
$40.66

22. Voltage Regulators Features Linear Voltage Regulator
Switching Voltage Regulator
Function
Step down only, output voltage must be less than input voltage
Steps up or Steps Down the voltage, can produce multiple outputs.
Size
Small to medium in portable design, may be even larger if heat sink is needed
Small in size, consumes low power
Efficiency
Low to medium
High
Noise
Low
Medium to high due to ripple effect
Output Ripple
Very small almost negligible
Large
Waste Heat
High, when load and voltage difference is high
Low, most components will run cool for low power levels

23. Voltage Regulator (Con’t)
Items
Input Voltage (V)
Current Rating(A)
Motor 12
Up to 6 (A)
Raspberry Pi 5
2 (A)
Servomotor
0.5 (A)
Camera
0.5(A)
MSP430
3.3
230 (uA)

24. Webench Tool

25. Raspberry Pi Breakout Board / PCB
RC Car Platform
12V Reg
Motor
Enough Space for Components
Capable of Speeds of +20 km/h
Low Center of Gravity
Has a Steering System
Has Predetermined Spacing (e.g. Space set for Battery, Motor )
Proto-Board
3.3V Reg
Cam
Raspberry Pi Breakout Board / PCB
5V Reg
Batt
1:4 Scale GoKart

26. Administrative Content

27. Work Distribution Section Bryan Victor Khanh Luis System Definition M
Power
Motor Control System
Computer Vision S
Electrical System
PCB Design
Protoboard/Integration
Legend M: Main
S: Support

28. Budget and Cost Initial Estimated Budget Test and Development Cost
Estimated Production Cost
Item
Qty
Total Cost
Sensors (various)
Various
$100
Car Body 2
PCB Fabrication 1
$70
Misc. Electrical
$150
Misc. Mechanical
IP Camera
$110
Tablet
$200
Pan/Tilt Mechanism
$50
Battery
$60
TOTAL
$910
Item
Qty
Total Cost
PCB MfG/BoM 2
$230
Car Body 1
$81.00
Dev. Boards
$145.00
Misc. Electrical
Various
$446.00
Misc. Mechanical
$63.00
USB Camera
Owned
Boeing
$580
TOTAL
$965
Item
Qty
Total Cost
Ultra Sonic 1
$4.00
Car Body + Motors
$81.00
Raspberry Pi
$35.00
Misc. Electrical
Various
$150.59
USB Camera
$50.00
PCB MfG/BoM
$115.00
Battery
$40.11
TOTAL
$475.50

29. Issues Steering Angle: Limited between 45 to 135 degrees.
Processing time depends on video resolution.
Tracking distance is limited by video resolution.
Voltage Regulator PCB (12 and 5V) not functioning.
Ultrasonic sensors acquired proved to be inaccurate.
Inertia Measuring Unit (IMU) malfunctioning.

30. Q&A Session