S.I.T.C.H.

Aziz AlbanderMatt Certosimo

Albert ComoVincent Din

Lex TelischakTyler Troup

Overview Design of a semiautonomous robot Transmits video feed back to user Drops relay module for extended range Utilizes laser range finder to navigate

unobstructed return path Pre-constructed robot chassis

Objectives Implement remote control Equip rover with laser range finder:

Object DetectionPath finding

1500mW, 2.4GHz video transmission Top roving speed at least 2mph 640x480 video resolution Hopeful for 100m navigation range

Design Goals Module Low Medium High

Power Buy TI Chips/ etch PCB

TI Controller chips; design converters

Design all controllers and converters

Sensing Stereoscopic camera vision

Single Laser and Camera

Line laser

Image Processing

Stereoscopic camera vision

Obtain distance and angle from single laser

Obtain distance and angle from line laser

Board Layout Etch analog control circuit

Print digital control circuit

Dual core processors on one board

Motors Elbow grease Servo Motor moving sensor

Servo motor moving sensor 2 dimensions

µproccessing RC Analog ARM or FPGA to perform digital decoding/processing

ARM and FPGA to increase processing power and store location/mapping

Booster None Increase operating range from user

Multiple boosters

Collision Sensing

None Bumper/Ultrasonic None

Power Supply

Power Supply The goal of the power supply system is

to provide all the loads with necessary power level

Batteries and separate control circuits will be used for each subsystem

We are still undecided if we want to design and build converters or if we are going to buy power management chips from TI

At low level: Buying a DC/DC convertor to divide the power

through out the circuit Getting all the devices on an etched circuit boardAt medium level:Buying the controller and design the buck DC/DC convertor At high level:Design the controllers that control the power on the circuit and design the convertors to divide the power throughout the system

DC Batteries

Robot Power SupplyDriver Motor Controllers

Processor

Sensors

DC motors with brass brushes and 75:1 steel

gearboxes

Motor Controllers

Motor for Camera

Receiving

ProcessingSensory Transmitting

MotorsData Storage

Transmit Receive

Receive Transmit

Transmit Receive

ROBOT

BOOSTER

USER

High-level System Block Diagram

Distance Sensing

Laser Range Finder Theory

But what is “tan θ” ?

(1)

Finding The AngleTo find the angle used in the distance equation a few things may be needed:

What pixel is the brightest on the camera?How far is that pixel from the horizon?How many radians per pixel pitch?

Number of pixels can be counted from the center of the focal plane

The other parameters will be found by calibration table:

(1)

(1)

(1)

Beam Shaping with Cylindrical Lenses Spreading the beam horizontally will

allow for more distances to be calculated at a time

(2)

Beam Shaping Can be done with a cylinder of water

A different Range finding option

Professor Siewert’s description of machine vision in his real-time imbedded systems book Uses two camerasStill finds distanceCons: Pro:Computationally more intensive More support available if we get stuck

(3)

Image Processing Options Brightest pixel Single distance

Line of bright pixels Multitude of

distances

MathLaser

Fix focal lengthMeasure beam diameterDetermine beam spread in 1 dimensionDetermine

Board Layout

Board Layout Goal – Low We plan on etching

our own analog control circuits for the motors

Kits are available from Jameco.com that allow us to etch at least 5 circuits for under 45$

(4)

Board Layout Goal – Medium + High We plan on utilizing

Altium to layout a digital control circuit

Then our designs will be sent to Advanced Circuits in Aurora to generate a PCB

For our high level goal we plan on printing multiple processors on one board

(5)

(6)

Motors

Motors - Low No motors Manual control

Motors - Medium Use of single servo

motor Horizontal Direction

Motors – High Use of dual servo

motors Horizontal and

vertical directions Implementation

Motors connected

Processing

Processing – the PossibilitiesFPGA Cyclone II ARM Cortex-M0

We may even use a combination of the two types

(8)(7)

Processing: RC control RC control requires basic

processing PPM signal must be

analyzed by a processor Processor must provide

a combination of PWM and digital signals

(9)

Processing: Preparations for Autonomy Sensor data must be

made sense of Sensors include a laser

range finder and encoder Data from these sensors

must be interpreted

(10)

Processing: Full autonomy. When all sensor systems

are functional Use the laser range

finder to generate a map Use encoder to track

position in said map Use map data to find

paths

(11)

Booster

Signal Booster - Medium Level RC and processed video signals must

be relayed back and forth between both the S.I.T.C.H. and the booster module along with the S.I.T.C.H. and the user

Signal must be boosted to increase the range of operation and communication of the S.I.T.C.H.

The S.I.T.C.H. should be able to return to the user without ever losing signal

Signal Booster - High Level The Signal Booster will also have

filtering capabilities, allowing us to increase our signal-to-noise ratio

Implement the use of multiple signal boosters, allowing the S.I.T.C.H. to continue past the range of the initial signal booster

Collision Detection Implemented using either an ultrasonic

range finder and/or a collision detecting bumper

Collision Sensor The input of the sensor is the sensing of an obstacle The output of the sensor is a signal sent to the

processor in order for the processor to make and decision and tell the motors to react accordingly

Functional description: When an obstacle is detected the sensor will send a signal to the processor and then the system will know a collision is about to occur and take proper action to avoid the object

Test plan: We are going to test the sensor by placing an object in front of the sensor and measuring the resulting voltage

Collision avoidance This ultrasonic range finder:

Detect objects directly in front of itCan stop robot from hitting stray cats and

childrenReal time

Collision avoidance Bumper Hits something and reverses

Things that must work

A jumping off point

Mechanical Devices

Dagu Wild Thumper 4WD All-Terrain Chassis – Chrome

We have already purchased and received this chassis..

Robots Motors Implement motor controllers for the 4

DC motors with brass brushes and 75:1 steel gearboxes to control the robot’s movements

Solution: Opto-isolation Chips

Risk: Initial Motor Current Spike

Each of the 4 motors on the robot has its own controller, therefore we will need at least 4 opto-isolation chips to protect the motor controllers

Need 6 Channels minimum; undecided if we want 4 3-Channel chips or 12 1-Channel chips

Depends heavily on available board space

Safety Concerns

Safety Concerns

Laser Danger RF Exposure Possibility of Collision Small children

Communication

8 CH Wireless Audio Video 2.4 GHz 1500 mW Transmitter and Receiver Kit

Wireless video transmission – Safergaurd.com

RC 4 channel control RC control signal

generators Transmitter

Robot Parts and expenses Parts Quantity Cost ($)

Rover(robot chassis+4 DC motors)

1 265.95

Motor Controllers 4 Unknown

Remote control for rover

1 20-57

Receiver for remote control

1 13.99

Laser 1 19.69

Stepper Motor/Controller

1 Unknown

Camera 1 Unknown, ~$10?

Optical Encoder - -

Video Trans/Receiver Pair

1 160

Processing Parts and expenses Parts Quantity Cost/quantity ($)

ARM Cortex-M0 1 20 (E-store)

Booster Parts Unknown Unknown

Opto-isolators 4 Unknown

SD Memory Unknown Unknown

Task

Microcontroller (communications)

Matt Vincent Lex

Signal Processing Vincent Matt Aziz

Power and supplies

Tyler Aziz Lex

Optics and circuitry

Lex Aziz Tyler

Board layout Albert Matt Vincent

Image processing Matt Vincent Lex

Motors Tyler Aziz Albert

Mechanics Albert Lex Aziz

Division of labor

QUESTIONS?

Citations (1)

http://sites.google.com/site/todddanko/home/webcam_laser_ranger

(2)http://www.shokabo.co.jp/sp_e/optical/labo/lens/lens.htm

(3)Real-Time Embedded Systems and Components – Sam Siewert

(4)http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2113244_-1

(5)http://products.live.altium.com/#r10/explore/bd-PcbLevelDesign

Citations (6) http://www.4pcb.com/about_us/ (7)

http://www.altera.com/devices/fpga/cyclone2/cy2-index.jsp

(8)http://www.arm.com/products/processors/cortex-m/cortex-m0.php

(9) http://www.instructables.com/id/Put-your-RC-car-under-computer-control/

(10) http://www.instructables.com/id/3-D-Laser-Scanner/

(11) NASA Curiosity