October 21, 2003 ECE Senior Design1 Autonomous GPS-BOT Preliminary Design Review by Kery Hardwick, Yevgeniy Khasanov, Naoya Kinuta, Zhe Chuan Luo
October 21, 2003 ECE Senior Design2 Outline Objective: Our goal for the Senior Design Project is to design an autonomous robot/vehicle which is to be guided by a GPS system and equipped with a collision-avoidance system. Project Specifications: The BOT will be inputted with longitude and latitude coordinates of the targeted destination. Determining the direction of the target, the BOT will proceed to the targeted destination. If the BOT comes upon an obstacle in its path, it will find a path avoiding any collision. A robot implementing the same wheel base as the one we are going to build
October 21, 2003 ECE Senior Design3 Outline continued… Preliminary Design: –GPS –Electronic compass –Sonar sensors –Three-wheel (2 powered wheels) vehicle BOT –Interfacing the above components with microcontrollers MDR Prototype Goal: –Interfacing of components –Speed/direction-controlled BOT base –Powering scheme
October 21, 2003 ECE Senior Design4 Garmin® GPS 35 TracPak Track up to twelve satellites at a time One-second navigation updates Low power consumption Integrated antenna 3.6v - 6.0v power supply rating 2 rs232 serial interfaces -Essential Components- GPS Receiver The GPS receiver will communicate with a microcontroller via a rs232 serial interface. We have already tested the operability of the GPS receiver through rs232 by attaching the receiver to a computer Uses the standard NMEA 0183 sentence transmission protocol non-WAAS (Wide Area Augmentation System)
October 21, 2003 ECE Senior Design5 -Essential Components- BOT Base and Other Components BOT Platform Zagros MAX ‘97 Dual 12 volt 20in-lb torque drive motors The Max speed is 18 m/min Two large drive wheels and a caster wheel Should be able to move on grass as pictured on the right (taken from www.zagrosrobotics.com) Other Components: KVH C100 Electronic Compass 2 Sonar Sensors Keypad & 4-line LCD Screen 3 PIC16F877 PIC microcontrollers Servo Motor Base motor driver Motor Driver
October 21, 2003 ECE Senior Design6 -Essential Components- Other Parts - details 12 button keypad (non-matrix) 4 line LCD able to display our current coordinates, destination coordinates, and the number of satellites in use Servo motor with a turn angle of no less than 270 degrees for supporting the secondary sonar sensor 3 16F877 PIC microcontrollers supporting rs-232 and I2C transmission protocols Actual keypad that will be used in the design
October 21, 2003 ECE Senior Design7 -Essential Components- Power Supply Main Power source: Power-Sonic 12 Volt 2.3 Amp Hour Two 12 volts Power-Sonic batteries: -Analog (2 vehicle motors) -Digital (GPS, Compass…) DC-DC voltage regulators: Receive current from one single power source and convert input voltage to desire output current Power-Sonic Power source 12V DC Voltage Regulators Digital Components LCD: 6.5V PIC (3units): 5V each Keypad: 5V Electric Compass: 5V GPS: 5V Sonar Sensor: 5V
October 21, 2003 ECE Senior Design8 Power Budget of the System Maximal Voltage (Volts) Optimal Voltage ( Volts) Current Consumption (mA) Power Consumption (mW) Dual Channelt Motor Driver (Servo Motor)355.58004400 Max 97' Motor (per driver)12 130015600 Electronic Compass551575 LCD Display6.5 426 Sonar Sensor (per unit)551575 GPS unit63.6 - 6120 - 140870 mW Keypadnegligible
October 21, 2003 ECE Senior Design9 Preliminary Design Part 1 - Positioning and Bot Coordination GPS is the primary component. It will inform the BOT of its current location. A microcontroller will collect the GPS coordinate data and pass it on to the second microcontroller that will combine the received GPS data with electronic compass data and calculate the direction vector for the BOT As mentioned above an electronic compass will be a supplemental to the GPS in determining the direction the BOT needs to move in and the direction the BOT is facing. The precision of the electronic compass will also be significant factor in our successful completion of the project.
October 21, 2003 ECE Senior Design10 Part 2 - Object Avoidance Sonar sensors will also be mounted to detect obstacles in the way of the BOT. 1. One sonar facing in the direction of the movement of the BOT 2. Second sonar mounted on a servo motor facing the direction of the target The BOT itself will be based on a two-drive-wheel vehicle, each wheel equipped with a motor of its own. There is also a caster wheel Finally the microcontroller will interface GPS, electronic compass, sonar sensors and motors of the BOT to take inputs and process into information needed for our project. PIC 1 GPS Compass Keypad Sonar 1 Sonar 2 Servo PIC 3 PIC 2 LCD Motor Driver Design Block Diagram
October 21, 2003 ECE Senior Design11 1.The BOT will first be inputted with a set of targeted coordinates into a keypad. 2.The BOT will initialize by determining the direction it is facing and positions itself so that it faces the direction of the target. 3.The BOT will proceed in the direction of the target until it comes upon an obstacle. Two sonar sensors will be mounted on to the BOT. The first sonar (target sonar) will always be pointing in the direction of the target mounted on a servo motor, and the other (front sonar) aiming straight ahead of the BOT. 4.When target sonar senses an obstacle, the BOT will turn left until the front sonar does not detect anything in its way. When front sonar is clear it will proceed until target sensor does not sense anything. 5.When both sensors are clear it will proceed to the target. 6.The procedure will continue until the destination coordinates and the current coordinates, fed by the GPS unit, matches. -BOT in Action-
October 21, 2003 ECE Senior Design12 Final Project Specifications Operate the BOT at the speed of 18 meters/min in a terrain including grass and pavement Avoid all contact with objects of reasonable shape in the path of the BOT Reach the destination with the accuracy of 10 meters radius of the target (in good weather) Note: the precision of the GPS receiver will be the limiting factor in the design. According to prior measurements we expect the engineering quad to have a grid resolution no better than 5 by 10 squares.
October 21, 2003 ECE Senior Design13 Proposed MDR Prototype Specifications Our goal for this semester is to: interface the GPS, electronic compass and the user interface (keypad and LCD) so data can be taken in and processed. When this stage is completed we should be able to accept GPS positioning data from the receiver, display it on the LCD, and do the same for the electronic compass. We will also be able to accept input coordinates from the keypad and display them on the LCD test the speed, turn radius and power consumption of the BOT base only and be ready to assemble the BOT itself (without object avoidance)
October 21, 2003 ECE Senior Design14 Work Load of Members Kery Hardwick- LCD-Keypad Interface & Compass Interface Yevgeniy Khasanov- GPS Interface & Data Parsing Naoya Kinuta- Carbot Control, GPS Data Acquisition & Web Manager Zhe Chuan Luo - Power Supply & Compass Interface
October 21, 2003 ECE Senior Design15 Time Table of Senior Design Project Nov. 17-23Nov. 24-30Dec. 1-7 Naoya GPS Testing, Data Acquisition, Carbot TestingCarbot Control AaronPower Supply Compass interface Compass Interface Zhenya GPS Interface GPS Testing, Data ParsingGPS Interface Kery LCD-Keypad interface Compass interface Compass Interface