Peek Bot

1
Peek Bot

• Karthik Balakrishnan, David Bauer, Siddharth
  Easwar, Sagen Johnson, Saud Khan, Vidit Nanda

Johnson
2
Possible Applications

• Espionage Craft
• Extreme Condition (Environmental) Vehicle
• Artificial Intelligence Robot
• Navigation Control System for Emergency Boats
• Aerial Extreme Video Game

Johnson
3
Robot Control
Direction Control
Speed Control
Johnson
4
High-Level Block Diagram
Network link
Computer running Web Server
Robot
Camera Receiver
Remote Computer
Easwar
5
Robot System Block Diagram
GP2D15
ER21
GP2D15
PIC18F452
Control byte
GP2D15
Status byte
GP2D15
Robot Controller
Connection to Control Computer (802.11b/RJ-45)
Easwar
6
Hardware Robot and Sensors
Easwar
7
Hardware Microcontrollers

• The PIC microcontroller that is used to handle
  robot movement and obstacle avoidance

• The ER21 board that will be used to receive
  commands, and send status bytes via ethernet or
  wireless

Easwar
8
Hardware Camera and Sensors

• X10 Camera that will send a wireless video feed

• Sharp GP2D15 Proximity Sensor to avoid collisions

Easwar
9
Robot Control

• 4-wire connection.
• Duty-cycle provides variation.
• Multiplexed directional and turning inputs.
• Timer interrupts used to produce duty cycles.
• Independently produced duty-cycles for turning
  and moving.

Khan
10
Proximity detection

• Check obstacles while waiting on duty cycle.
• Check the front three if going forward otherwise
  the check the rear sensor.

Khan
11
The Algorithm

• If current instruction is about to cause a
  collision, change direction.
• If/when obstacle is no longer in the way,
  reorient along original path.
• If surrounded by obstacles, stop and send error
  code to user.

Khan
12
The Issues

• Generic Path-planning problem.
• Batch Instructions.
• Sequential Execution.

Khan
13
Wireless Interface

• PIC is interfaced to an ER21 wireless development
  kit
• ER21 is controlled by a PIC18F452 also
• I/O interface lines required to transmit
  information from this PIC to other PIC
• Will be used to transmit batch instructions to
  robots PIC from user-controlled web site

Balakrishnan
14
ER21 Capabilities

• 32 KB storage for web pages
• IEEE 802.11b wireless PCMCIA card, supporting
  both infrastructure and ad-hoc networks
• IP, UDP, TCP, HTTP and DHCP capability
• Web server for easy wireless configuration
• Uses 9 pins on PICmicro to drive wireless card

Balakrishnan
15
Web Server Configuration
Balakrishnan
16
Input Web Interface

• Input from web interface
• GUI
• Human readable scripting language
• CGI Program converts input to byte code
• Move forward for 10 seconds -gt 0x04, 0x0A
• Set turn right to medium -gt 0x20, 0x02

Bauer
17
Byte Code

• Two byte instructions
• Easy for microcontroller to decode

Example Instruction
FORWARD 1-7 0-15 Makes robot move forward at
designated speed. Upper Byte 4 Lower Byte,
Upper Nibble Speed (0-7) Lower Byte, Lower
Nibble Time (0-15)
Bauer
18
Video Feedback

• What?
• Why?
• How?
• Where?
• When?

X10 XCam2 Model XX16A
Nanda
19
Why Wireless?

• Because its cool.
• PIC processing power limitations.
• And, most importantly wires get entangled!

Nanda
20
Streaming Video

• Have Cam -gt Web-server (WS).
• Want Cam -gt Remote machine (RM).
• Need WS -gt RM transmission.
• We stream the video over Ethernet.
• User Datagram Protocol (UDP).

Nanda
21
A Picture

• Is worth a thousand datagrams

Nanda
22
Cost/Marketing Analysis

• Sensors 40
• PIC18F452 45
• Radio Shack Robot 75
• Wireless camera 80
• ER21 Ethernet Kit 270
• Conclusion Marketable to large corporations and
  the military

Balakrishnan