Intro to Software Eng
Intro to Software Eng CSE 2410
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Marvin An Intelligent Obstacle Avoidance System Preliminary Design Review Package Team Members Kenneth J ernigan PL Mark Abramovs Azhar Khayrattee Jason Haynes Brian Pridgen Jon Ranes Matt Spurk Table of Contents Brian Pridgen Preliminary Design Review Parka 0e Table of nntentq Top Level Description Technical Speci cations Current Gantt Ch art Design Options Positioning Systems Command Communication Systems Sensor Systems Computer Control Systems Motor Controller Systems Power Supply Systemq Drive System Frame Design Selection and Rationale Bill of Materials Preliminary Sketches Financial Statm Appendix 1 Current Business Plan Top Level Description Preliminary Speci cations Product Value P quot39 Team Organization Chart Team Capabilities 39 J39 391 39Strenoths Competitive Analyqu Risk Analysis OutOf Bounds Top Level Description Kenneth J emigan With the increasing power of computers the complexity of tasks that are becoming routine is also increasing Computers are now expected to make more decisions without human interaction In the past machines simply performed repetitive tasks without monitoring the environment around them Now with increased processing power and sensor accuracy machines can react and interact with their surroundings This concept is leading to a new autonomous class of robots and machines These new robots can be assigned a task by a user and then released The control system of the robot will have the power to recognize problems and obstacles in its path through sensor inputs and the processing power to circumvent them without further user interaction Marvin will be such a robot capable of moving from one location to another avoiding obstacles between it and its destinations with minimal instruction by the user Our robot will be a crawler that uses a combination of brains and brawn to recognize and react to potential obstacles in its path while maintaining and accomplishing its overall task assigned by the user Practical applications for Marvin are numerous Marvin can be used in a corporate or home setting as an autonomous delivery vehicle The vehicle will be cost saving as it requires minimal human instruction to operate Also the robot can be mechanically modi ed to access places not easily accessible to humans such as crawl spaces and other tight areas With proper shielding Marvin can also be used in areas dangerous for humans such as high voltage or radioactive environments For the military the uses are equally versatile A crawler particularly a small model can travel inconspicuously through hostile territory Adding reconnaissance equipment to the robot will provide valuable information about the area without excess risk to human life The crawler is also cheap and expendable at least compared to human life and so would be ideal for use with ordinance disposal Marvin will be a small rectangular crawler robot approximately one to two feet in length and width It will be light enough for one average adult to carry easily and less than one foot tall This height should provide stability when traveling over at uneven terrain The frame will have several inches of ground clearance to allow passage over small rocks or other obstacles Components will be mounted directly to the frame or to an internal mounting rack included for that purpose The exterior will be covered to prevent incidental damage to sensitive subsystems On the rear of the frame a series of ports will be mounted for recharging and diagnostic purposes For tracking and obstacle avoidance purposes Marvin will include multiple sensors The primary group will provide long range sight to the vehicle These sensors may or may not include a vision system but they will be capable of seeing and detecting obstacles in the distance 310m Marvin will continually scan ahead seeking out the obstacles and in turn react to avoid collision with them Within the three meter range the primary group of sensors would not detect obstacles but the secondary group would The secondary group will be capable of detecting obstacles within three meters in front of Marvin up to physical contact These sensors will be in place to detect the obstacles that the primary group of sensors fails to detect or that appear in front of Marvin due to course or heading changes The close range sensors will detect more types of obstacles that would be capable of hindering Marvin s progression To aid Marvin in movement a positioning system will be included The system will include a sensor on Marvin that will determine its absolute position anywhere on earth Marvin will use this absolute positioning system to track its relative movement as well The sensors will interface to the central processing unit where they will be used in determining the robot s actions The obstacle avoidance algorithm will have to maintain the systems ultimate destination in mind while traveling This goal will have to be balanced with the systems reaction to obstacles that appear in Marvin s path while it is traveling to this goal Marvin will have to react to obstacles that are detected in its path as quickly and efficiently as possible and then continue towards its goal Avoiding obstacles is not sufficient Marvin will have to bypass them and still reach its nal destination if possible The system will also have to be capable of recognizing both when it has achieved its goal and when the goal is not reachable Marvin will have some form of communication with the host computer at any point during operation and will be capable of accepting commands at any time The robot will be capable of reporting current location and status to the host Status will include information concerning the physical and digital state of the robot Digital states will include waiting for next instruction traveling to destination avoiding obstacle or unable to reach destination The base machine will be running host software that will issue commands to Marvin The commands can either be a final destination in the form of absolute coordinates or a request for information collected by the robot Users of the host will be presented with a graphical user interface that will report all data collected from Marvin and will be provide options for issuing commands back to the robot unit The software will also keep a recent history of locations traveled and data collected Users will have options of entering absolute or relative coordinates for Marvin s next destination Users will also have the option to allow roaming around an area defined by the user The host machine will then tell Marvin locations to travel which should be randomly selected within the defined are a Power Supply Positioning System Sensors Microcontrollers Communications Base Station User Interface System Applic ation Motor Control Drive System Technical Speci cations Brian Pridgen Extended Memory for Current to Motors to Motors Regulated Voltage Current Current Maximum 7 mph in 33 sec Current Gantt Chart Kenneth J emigan quot3 TaSkm 124303 l8epZB3903 Muz39os Inscz39os IBn113904 Feb153904 Ilva39 WITIFIS SIMITIWITIFIS SIMIT 1 thin 2 v 2 WHOJects 29 v v 3 WE39qu 29 v v 4 WE39qu 29 v v 5 Ensigwwasite 100 K1 6 Locate mlrg 2W K 7 laelome 70 I K1 8 Aoqu39renans 0 K1 9 Satedeer 80 39 U 10 Saenertofmbrk 80 39 39 11 Satemertofok 80 39 U 12 cmpose all of Materials Raisim 1 80 KJ 13 meanmtdek 80 I 14 Teanwmwadsom 0 o 1028 15 SstemDesigI 45 F 16 PER 99 39 ll 17 PER 99 39 ll 18 msearchweuaricalaoas 100 N H 19 IResearchnbrooorirdleraoezs 100 20 mm 100 T Researches 100 F 22 Researchmech 1cm P T cumleFERRadage 100 EP T WFERSKES 100 KJ T SJrritFERFange 100 T Iudeelir ri arstig Raiav 0 1014 5 Task Name 24 3903 2303 Feb 15 3904 Mar21390 31e Sep39 I318 Nwz 2 39 lDac73903 17 2 171 hn113904 I16 I 31 151 I16I31 WW 8 8 8 8 91 8 8 52 8 8 3 ala ala a a s a a Q Ql E E SQ SEIR 03 CD Hddype Sstern SelectaaetsfromFER VWtespecsoanrocnm39dler VWteaaecsonSbrsa39s VWteaaecsonGZS VWteWelesstmu ic a onauecs Orrposesmvm eOerviev Dasig Fbveraniyforhbd39aical Dasig Fbveraniyfordg39lalcxx rw39erls VWteMad a icalaaets SJrriCIRFazlage IUan39tic al Dasig Raiev Wor Qrtrol lrtetfaoe Was and Cbrtrols Med39a39icd Qwrponerts BJld Oasis AssemJIe Dive BJld C asir39gS39ell BJld Mad erical szer agony Sersors Wm G38 AssenueGEUit Nicrooortroller H ampE llt E i E s 1 A E 3 B SR gt4 IA 1 1 A 1 MS NB MS Task Name 24 3903 3903 Feb 15 3904 Mar21390 31e 8amp028 I318 Nwz 2 39 Dac739o3 17 2 17 1 m1139o4 I16 I 31 151 I16I31 3 8 8 Q 8 8 9 8 B 9 8 8 6 3 E d w EB 9 quot 89 81 83 R 9 8 a 81 31 3 64 Softwa39e VVite MJtor Ortrol iterfaoe VWte Sbrsor Herfane VVite ChstajeAVmNgxi Tn VWte FamAgu39m Test Esuts Uit Test Esuts VWte test case for G35 VWte test cases for sersors VWte test cases for r r39nrooom39dler VWte test cases for rmtor oortrol VWte test cases for Cbstade Avoicbrne Cbrrpile resuis lrteg39aion Test Esuts Assemble ir39teg39aed Ln39t Mte irtetfazirgtest sd tmrdre Orrp39le M Hm Desig39l Hm Desig39l nal Dsig Flr Prodn a39ld Dam Sstern Sstem VWte Ease Sz on Samware W Rnbot Test Esuts Sstem Test msuts V v B3 R 4 4 4 iIB 4 Design Options Positioning Systems Brian Pridgen Global Positioning System GPS Antenna for satellite reception Positioning Processing unit for System position calculations Serial 10 port for communication GPS units are the standard for lowcost positioning systems They use satellites to determine the current location and time Most units can then compute basic information such as distance traveled current speed and current heading Pros 7 Most manufacturers produce at least one unit designed for embedded applications interfacing with a computer or microcontroller so a selection of units is available All of these support a standard documented serial interface and protocol for communication with the unit These embedded systems are designed with size and power efficiency in mind A standard commercial unit is available for around 200 dollars Cons GPS units have several performance limitations Most units feature a one hertz data update which will either limit the speed of Marvin or require attentive so ware programming to ensure that destinations are not overshot during transit Also GPS units suffer a loss of accuracy while moving or while indoors which may provide difficulties during the demonstration Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price Embedded GPS 1 Unit 1 l 200 N200 Inertial Navigation Systems INS Antenna for satellite reception l Inertial Sensors l Processing unit for position calculations Serial IO port for communication H Position correction algorithm INS units combine the satellite location capabilities of GPS units with a sensitive inertial system for error compensation during movement Pros INS units maintain a higher accuracy during movement by using the inertial sensors to counteract error within the GPS system The will also work better in doors particularly for our relative use of the positioning functions provided a rough fix has been determined Cons INS units are very expensive two to ten thousand dollars Most companies use different error compensating algorithms Although they still provide the same standard interface for serial communication full use of the INS functionality often requires extra productsensitive communication with the device Bill of Materials Line Part Description Manufacturer Quantity UM Price Extended Item Number Price Embedded INS 1 Unit 1 l 2000 2000 Command Communication Systems Brian Pridgen Wireless Network Communication Base station wireless network card Communication W 1 System 1re ess router Robot wireless network card Wireless Networks all for the radio frequency communication between the base station and the robot wirelessly using standard network protocols Pros 7 With the recent increase in wireless networking these parts are readily available All of the local computer stores have the cards and routers necessary to make the communication link functional Also use of network protocols would allow for the development and implementation of a more complex base stationrobot communication interface Cons Wireless networking would require the purchase of a wireless networking card and a wireless router both of which are still expensive Also the readily available components are designed for desktoplaptop use and are not powerefficient Bill of Materials Line Part Description Manufacturer Quantity UM Price Extended Item Number Price Wireless network 1 card 2 1 60 120 Wireless network 2 router I 1 100 100 Wireless Serial Communication Communication System Most robot communication is done with wireless serial communication Purchase of two Base station serial port Base station wireless serial transceiver Robot wireless serial transceiver Robot station serial port transceivers will allow for twoway serial communication between the base station and the robot through the serial ports Pros The wireless serial components are slightly cheaper than the wireless networking system Also the units are designed for robot use leading to ef cient power use Finally some microcontrollers don t support networking communications but almost all support some form serial communication Cons Serial communication limits the complexity of the command and response messages Communication is signi cantly slower than wireless networking Also the units tend to be fairly short range Bill of Materials Line Part Description Manufacturer Quantity UM Price Extended Item Number Price Wireless serial 1 transceiver 2 l 80 l60 Wired Serial Communication Communication System Pros Base station serial port Crossover serial cable Robot station serial port It is possible to have an external plug on Marvin for attachment of a serial communication wire Avoiding the necessity of RF transmission makes this option the cheapest of the three alternatives Having a physical connection to the robot would also provide the most reliable form of data transmission Also if the cable was detachable the cable could be used as a publicity boost by signifying the autonomous nature of Marvin by removing the cable after commands had been issued but before the instructions were executed Cons Cables get tangled and kinked They are frequently wrapping around other obstacles particularly when in connection with a moving robot Also the base station must stay within a short specified distance of Marvin Finally wireless features are more appealing to the public than dangling cables Bill of Materials Line Part Description Manufacturer Quantity UM Price Extended Item Number Price Crossover serial 1 cable 1 l 15 15 Sensor Systems Azhar Khayrattee Infrared Sensor System LED to generate and receive IR Processing unit to generate output 1 to 2 IO lines for communication Infrared as the name implies uses an IR beam to detect objects A LED is usually used to generate the beam The re ected beam is then analyzed to nd the distance of the obj ect Pros It has a good range of detection 24m The processing time ie the time rewired to calculate the distance is usually minimum It is much cheaper that ultrasonic Usually external circuitry is unnecessary the IR interface can be connected directly to the microcontroller IO Cons The ambient light in the surroundings might affect the reading Colortype of material of objects will also in uence the sensor Flashing lights into the sensors will also affect readings Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price 1 Infrared Sensor 1 l 40 40 Ultrasonic Range Finder Sensor System Sound wave generatorreceiver Processing unit to generate output 2C interface or Serial O communication Ultrasonic sensor uses sound waves to detect objects A sound wave is sent out and the returning echoes are analyzed to calculate the distance the time interval is usually used Pros Ultrasonic sensors usually have large range of detection up to 11m The intensity of light or color or type of material of the object will not affect the readings Some Ultrasonic sensors can even be used to detect the shape of an object For example if there is a passage in the wall a narrow doorway the vehicle would be aware of it Cons Ultrasonic sensors are relatively expensive compared to Infrared Sensors Some Ultrasonic sensors have a high processing time ie they take a longer time to give an output Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price 1 Ultrasonic Sensor 1 l 100 100 Magnetic Compass Sensor System Magnetic coils to sense Earth s magnetic field Processing unit to generate output 2C interface or PWM communication Magnetic compasses are digital circuits which give outputs depending on the earth s magnetic led They will be useful for guiding the vehicle Pros It is a very small and compact unit It is cheaper than the sonar sensors They are usually very accurate they can give relative positions correct to 1020 This would be very useful to guide the vehicle to its destination Cons It can be rather time consuming to program It is more expensive than the IR sensors if an accurate unit is considered Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price 1 Magnetic Compass l l 80 80 Accelerometers Sensor System Heated bubble of air used to measure gravity Processing unit to generate output Analog output Serial O port communication Accelerometers are electronic circuits which use the earth s magnetic eld to calculate the acceleration of a body Some of them use a small bubble of air to determine the acceleration These sensors are either single axis or double axis detectors ie horizontal and vertical acceleration Pros They can provide useful information like if the vehicle is going down a dangerous slope They can be used to adjust the braking required if the vehicle is to operate at variable speeds Cons They are rather expensive units The detection of slopes can be done otherwise using the IR or sonar sensor It would draw power form the vehicle that could be used for other important devices Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price 1 Accelerometer l l 60 60 Bumper Sensor Sensor System Switch to activate interrupt Interrupt port Serial O communication These sensors operate on a very simple principle activate a circuitsend an interrupt upon contact with an obstacle Pros They are very ef cient for they detection of close objects or obj ects close to the groundioutside the range of the IR 0r sonar They are usually very cheap They require no external interface or complex programming They can be used as interrupt triggers Cons Some of the prebuilt bumper sensors are expensive It would be cheaper to build a system Contact switches will do the job Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price 1 Bllnper Sensor 4 l 20 80 Vision Sensor Sensor System Lens to capture light from surrounding environment LEDs or photosensitive devices to convert input to current Processing unit to generate output Serial O communication These sensors act like real time cameras They can detect both shape color and make 3D models of objects Pros This output of this sensor would be very useful on the collision avoidance mechanism Precise calculations can be made in order to avoid the obstacle efficiently If the vision sensor is used it would be redundant to include other sensors since it provides a very accurate depiction of the surroundings which makes it easier to avoid obstacles Cons This unit is usually very expensive and the decoding of the output is very time consuming They also consume a lot of power Moreover they are affected by sudden changes in lighting conditions and can give skewed pictures in poor lighting conditions Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price 1 Vision Sensor 1 l 200 200 20 Temperature Sensor Sensor System Tem perature sensor Processing unit to generate output Serial port or O ines communication This device detects the temperature of the ambient environment Pros It could be used to avoid hazardous temperature regions It is a relatively cheap unit and very compact Moreover the decoding of the output is rather simple Cons Accurate units are usually expensive It has no real use for the vehicle is not designed to venture in high temperature regions It would draw power from the vehicle which could be used for other important devices To get accurate readings the sensor would have to be placed far away from the vehicle thus making it liable to damage by obstacles outside the range of the sensors Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price 1 Temperature Sensor 1 l 40 40 21 Ultrasonic Movement Detector Sensor System Sound wave generatorreceiver Processing unit to generate output 2C interface or Serial O communication This device can be used to detect movement using sound waves Pros It can be used to detect moving obstacles The vehicle can then operate in a dynamic environment It has a very good range same as the ultrasonic sensors Cons This sensor is relatively expensive They usually require a long processing time to give an output Moreover the vehicle should be stationary to obtain an accurate depiction of the moving object It would draw power form the vehicle that could be used for other important devices Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price Ultrasonic 1 Movement Detector l l 50 50 22 Computer Control Systems Mark Abramovs MicroPlanet PIC Control System Microcontroller for robot control Interface board for microcontroller Converter for Analog sensor input Serial IO port for communication The microcontroller would be used in Marvin to control and interface the various sensors and movement systems The microcontroller would act as the brains of the robot Pros 7 The MicroPic is a cheap small powerful chip that would be utilized for the brains of the robot The MicroPic uses a reduced instruction set that would allow for quicker development with less time in the learning stage The various chips are under 10 and some are even free Because the chips are so cheap multiple chips could be used for the various parts of the robot control making the programming simpler Select versions of the chip allow for programming in the C language as well as in assembly language Select versions come with analog to digital converters for built in for interfacing with analog sensors Cons A more complicated interface board would be required for each MicroPic used This would entail a higher overall cost and a higher risk of equipment failure Most versions of the MicroPic only allow for programming in assembly this would increase the software development time as well as the complexity of the software Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price 1 PIC MicroPlanet 4 l 10 40 1 Interface board 4 l 30 120 23 Parallax Inc Basic Stamp II Microcontroller for robot control Control Interface board Convener for System for microcontroller Analog sensor input Serial IO port for communication The Basic Stamp II is a tiny single board computer built on a chip It uses a MicroPic for the microcontroller and runs a version of BASIC Pros The Basic Stamp II is a complete single board computer that utilizes a wellknown microcontroller The Basic Stamp II uses the BASIC language for programming instructions This feature would allow for a shortened development time This would reduce the complexity of the interface board required There are many off the shelf kits that utilize the Basic Stamp that could be used with Marvin The Basic Stamp 2 is a midrange solution at 49 Cons The Basic Stamp is a more expensive solution Does not include analog to digital converters built in the chip The programming is limited to the basic language this lessens the versatility of software development Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price 1 Basic Stamp 2 Parallax Inc 1 1 49 1 Interface Board 1 l 10 65 24 Embedded Microprocessor Board Microprocessor for robot control Control System Serial 10 port for communication An embedded microprocessor board is a computer that is built onto a single board The computer runs an operating system in real time Pros This is the most powerful option for controlling Marvin This board utilizes a microprocessor instead of a microcontroller The board can run various operating systems including embedded versions of Linux The system is easy to install offtheshelf software for integration with sensors and control systems The microprocessor would only require one board to run all of the systems on Marvin Programming could be done in multiple languages including C Cons This option would be expensive with prices starting at 200 It adds an extra layer of complication involving operating systems and device drivers This option would require a larger power supply possibly up to three times the amount for a microcontroller Analog to digital converts would have to be interfaced separately Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price Embedded 1 computer 1 l 200 400 25 Motor Controller Systems Jason Haynes All In One Integrated Circuit Package Motor Controller Sensor and positional input Integrated controller system Output signals to motors This design implementation is an integrated circuit control board with speed controller built in failsafes and builtin monitoring sensors Pros These controller comes ready to go out of the box setup is quick and easy plug and play theory They are very durable and offer extra useful features that may include motor and controller temperature monitoring overheat protection and serial mode support that allows monitoring Upgrade software and builtin brake function are also available in some models Cons Integrated motor controllers are very expensive up to about 400 and not customizable The size and weight may be excessive for an IC setup With an integrated design all circuitry is enclosed and may be hard to reach hence the black box problem may occur If a malfunction occurs it may be very difficult and time consuming to narrow down and locate the problem Since most integrated motor controller are designed for use in combat robots there are many features that will not be necessary for example ip input where the controls will become inverted should the robot be turned over Bill of Materials Line Part Description Manufacturer Quantity U M Price Extended Item Number Price Integrated Robot 1 Controller 1 l 250 250 26 Modular Design Sensory and positional input Basic robot Speed control Controller circuitry DC motor system Motor Controller This design is a basic controller with separate speed control circuit Directional control can be implemented using a relay or bipolar circuit or the more popular Power MOSFET transistors Speed control can be implemented using variation of Power MOSFET transistors Pros A modular interface has the advantage of being fully customizable Not only will features be obtained that are speci cally useful to the project but also the black box theory will be avoided If a malfunction occurs the source of the problem can be narrowed down easier This design will also be significantly cheaper than the integrated design since the speed controller circuitry will be build from scratch and individual parts are cheaper Cons Circuitry for this design will definitely be more complex than anything encountered before hence time will become a factor The design will be harder to implement and relatively detailed knowledge of the circuitry will be required Since parts of the circuitry will be built many variables such as overheat protection and overall circuit toughness keeping wires connected will have to be taken into consideration Hence the circuit will no be as durable Interfacing modular components such as the speed controller circuitry to the motor controller may be a difficult Bill of Materials Line Part Description Manufacturer Quantity UM Price Extended 4011 NAND 27 5 Switches 1 1 500 500 Component Based Controller Sensory and Positional input Directional control Motor Controller circuitry Hbridge Speed control circuit cucumy DC motor system This design will be a motor controller built with individually assembled components to speci cally perform features needed Pros This design is completely customizable therefore only the features that are necessary will be added hence controller may be more compact and no circuitry that will be there for no reason Design will also be relatively inexpensive since individual components will not be cost nearly as much Additionally since all components were installed by team members maintenance will be easier and malfunctions can be narrowed down quicker and more effectively Most importantly indepth experience will be gained by building a controller from scratch that will undoubtedly increase the skill and knowledge of anyone involved Cons A componentbased design will be seriously time consuming and finding individual parts alone may prove to a very meticulous operation Circuitry will definitely not be durable therefore methods of insulation will have to be developed in order to keep some systems apart Interfacing individual components may also be a challenge Since building from scratch there will be no methods available to monitor controller or motor temperature If circuit elements are damaged during the final stage finding replacements on such short notice may not be possible There are no warranty conditions to fall back on so everything needs to be built safely and effectively the rst time 28 Bill of Materials Line Part Description Manufacturer Quantity UM Price Extended 4011 CMOS Quad N channel Power MOSFET 4011 NAND Power Supply Systems Jason Haynes Nickel Cadmium Connection leads Power Supply Multiple Nickel Cadmium Battery Packs NiCads are available in all standard sizes plus special purpose sub sizes for use in sealed batter packs Most subsize batteries have solder tabs so that wires can be attached directly to the battery instead of placing the cells in a battery holder Pros NiCads are very inexpensive and easy to get They are ideal for almost all robotics applications Most manufacturers claim cells last for 500 or more recharges 29 Cons Batteries can suffer from memory effect whereby the use ll capacity of the battery is reduced if the cell is not fully discharged before it is discharged This can be inconvenient that the battery needs to be fully discharged before recharging Nicads polarity can change positive to negative or negative to positive Polarity reversal is common if the battery is left discharged for too long or if discharged below 75 or 80 percent Bill of Materials Line Part Description Manufacturer Quantity UM Price Extended Item Number Price 2400mah NiCad l BattlePacks 12V 1 l 40 40 Nickel Metal Hydride Power Supply Connection leads Multiple Nickel Metal Hydride Battery Packs NiMH batteries are also popular rechargeable batteries They are about the same size as Nicads but they deliver about 50 more operating juice Pros These batteries have low internal resistance they do not exhibit memory effect as the NiCads nor do not contain cadmium a highly toxic material NiMH especially works well in high current conditions They can be also be recharged at an aggressive rate thus can be recycled very quickly Cons NiMH batteries can get very hot when discharging especially at high currents Therefore they need to be placed away from control circuitry if implemented in robot NiMH packs relative to other rechargeables do not hold the charge well Over time charge in battery is depleted even while the battery is in storage They are also very expensive 30 Bill of Materials Power Supply These batteries are the same as those used in cars It is made up of essentially lead plates crammed in a container that s lled with can acidbased electrolyte These plates are very powerful and have respectable betweencharge life When the battery goes dead it can be Connection leads Single Lead Acid Battery Line Part Description Manufacturer Quantity U M Price Extended Item Number Price 2600mah NiMh l BattlePacks 12V 1 65 65 Lead Acid recharged just like NiCad They typically come in selfcontained packs Sixvolt packs are the most common but 12 and 24volt packs are also available Sizes of leadacid can vary up to about the size of a radio Pros Leadacid batteries are powerful They have high voltage range and provide high current for a reasonable time Additionally lead acids are easily rechargeable and relatively cheap Cons Leadacid batteries are excessively heavy Not uncommon for a car battery to weigh about 20 pounds Robot has to be large and sturdy enough to support the battery Bill of Materials Line Part Description Manufacturer Quantity UM Price Extended Item Number Price 12V 12AH SLA 1 Battery 1 l 50 50 31 Drive System Matt Spurk Tanks Tracks Motor Drive System Transmission Tread Assembly Tank Treads are used primarily in military and construction applications Treads use their large contact area with the ground to prevent the heavy vehicle they propel from becoming bogged down in loose soils Pros Tank treads provide a very stable platform even while crossing difficult terrain Tank treads will also provide great traction when slippery inclines loose gravel andor sandy surfaces are encountered The treads should eliminate any instances of high centering assuming appropriate ground clearance is used The tank treads also come as a complete assembly and should simply bolt directly onto the robotic platform Cons Tank treads are notoriously heavy and expensive If the tank treads were to be damaged a new track assembly would have to be purchased due to the limited availability of replacement components 32 Bill of Materials Line Part Description 12V drill motor 12V drill transmission ank treads includes left and Wheels Motor Transmission Drive System Shaft Bearings Wheels 33 With the wheeled platform we would also be executing method skid steer of turning the robot rather than a rack and pinion automotive style steering The wheeled platform would be constructed in a similar fashion to the tracks This is the easiest to implement and interface with the control electronics because unlike a rack and pinion setup which would require the front tires to return to center after executing a turn the robot would simply reverse one side of the drive while having the other side continue forward The robot would actually spin in place for a zero turning radius assuming even weight distribution Pros The robot would have a very stable platform that can be modified quickly and cheaply Of the three options the wheels are both the lightest and the most cost effective Wheels would require the least amount of parts to work effectively If a part happened to become damaged it could be easily replaced Cons Wheels provide good traction but can become highcentered on obstacles such as holes or bumps The design behind the bot would require additional ground clearance to navigate these obstacles Bill of Materials Part Description Manufacturer Dewalt transmission shaft must be 12v drill motor 12v drill transmission 34 Legs Actuator Leg Drive System Knee Actuator Foot A multilegged robot system is the best obstacleconquering device in our list A 6 legged walking platform is very stable mechanically because three points of contact are in contact with the ground at all times and remaining still Pros A legged robot is basically unstoppable as far as terrain is concerned Legs are also very unlikely to become high centered on dips or bumps as it moves along The walking platform is also the most creative and artistic in appearance Cons A stable walking platform is considerably harder and more expensive to implement The walking platform would require and alternative power source to provide locomotion such as 35 hydraulics or pneumatics as electric linear actuators are in general too slow for our purposes and also very costly A walking platform is difficult to effectively position sensors such that an obstacle is not missed while the robot is moving Bill of Materials Part Description Frame Cover Component Frame Rack Chassis The frame serves as our mounting surface for our components our cover to protect the components from the elements and as our test platform to verify the functionality of the components 36 Aluminum Pros The grade of aluminum we chose to use is Al 606lT6 This grade of aluminum has great machinability characteristics and can be welded Aluminum is also corrosion resistant and can easily be shined to produce a nice nish Due to the fact that aluminum is easy to machine the walls of the robot will also be used to mount both drive and electrical components We feel con dent doing this because of the strength characteristics of the hardened aluminum we will be working with We also have access to this aluminum locally at a reduced price Cons Aluminum has poor shear characteristics which makes threads in Al weak Normally aluminum is costly and dif cult to nd locally but as mentioned above a local source has already surfaced Bill of Materials Part Description Steel Bar skinned with Plexiglas Pros Steel bar provides a very strong frame material Due to the fact that the frame would not need to be subjected to large shock loads thinwalled steel tube could be used Steel is one of the cheapest metals and is easily accessible to the general public Steel is easy to weld making an ideal frame material The wiring for the robot can be run inside of the steel tube to protect the wires as well as add to the aesthetic appeal Plexiglas is highly available to the general public at low costs Plexiglas is also clear which provide a view of the interior of the robot without removing the covers Cons Steel is very susceptible to rust Steel is dif cult to machine Plexiglas is a fragile material and can shatter if hit with a moderate amount of force Bill of Materials PaIt Description 37 Design Selection and Rationale Decided by all group members Compiled by Brian Pridgen In general we are choosing not to design any components from lowlevel components due to the shortterm nature of this project For example designing a functional wireless communication card in time to start the prototype in February is not feasible with the allotted time or resources Instead we will focus on the interfacing of currently available units to deliver Marvin within the allotted time span For the positioning system we will purchase and interface to a commercial unit designed for embedded systems Most GPS companies produce a cheap and reliable unit that is considered the industry standard for approximately 200 The INS system while slightly more precise is definitely beyond the budget for this project For the communication system we will purchase two wireless serial transceivers that will allow for twoway communication between the robot and the basestation The rear of the vehicle will also include a port for attaching a serial cable to bypass the wireless link if desired The group feels that the wireless feature is important to show the autonomy of the robot Also adapting the microprocessor that we are using to serial communication will be easier and cheaper than network communication We will include the following sensors ultrasonic infrared magnetic compass and bumper contacts The ultrasonic sensor will provide a longrange 11m method for identifying objects in Marvin s prospective path Ideally any obstacles would be detected in time for Marvin to avoid it with only minor adjustments The infrared sensor will provide a close range 4m secondary system for obstacle detection The infrared system will be used to detect surfaces that were not picked up by the ultrasonic system The ultrasonic system has several conditions such as surface type in which it will not detect objects The bumper contacts will be the last line of defense to detect if Marvin actually hits an obstacle The bumper contact is necessary to prevent stalling against lowlying undetected obstacles Finally we will include a magnetic compass to determine the heading of the vehicle even when Marvin is not moving This will help in determining obstacle locations relative to Marvin and the destination The concept behind the bumper system is fairly simple so we will design it as an interrupt directly into a microcontroller The other three units ultrasound infrared and magnetic compass will be commercially bought units that will interface into the microcontroller We chose not to include the rest of the sensors because they did not fill major needs in Marvin s goals We will use multiple PICs to control Marvin PICs are cheap some companies will provide samples upon request They are also well documented for development and interfacing Because each PIC is single threaded we will include multiple PICs to control each of the sub systems Then we will have a master PIC which will be responsible for gathering the data from each of the subprocessors as needed and then interpreting this data We are going to design the motor controller ourselves rather than purchasing a commercial unit Commercial units are expensive and the design is rather simple Also the company we were looking at has made their plans opensource Therefore we can build our own motorcontrollers from components for less expense Building our own will also allow us to design the failsafe checks specifically for our performance creating an exact fit instead of a rough generalization 38 To power Marvin we will use a single sealed lead acid battery Leadacid batteries are cheap readily available long lasting and easy to recharge The battery will directly power the motors with an overcurrent cutoff switch to prevent overdraw The electronic components will also be powered by the battery but there will be attached through a voltage regulator circuit Physically the electronic components will be separate from the battery to prevent possible leakage or corrosion damaging expensive subsystems Finally Marvin will be driven by a track system Tracks will help Marvin handle rough terrain and increase the durability of the robot Tracks should be able to handle any obstacle that comes in beneath the bumper sensor Also tracks will provide maximum traction in any soft terrain Marvin encounters while trying to reach its destination The tracks will be powered by a pair of DeWalt drill motors These motors come with the transmission included Building the transmission would be a major mechanical endeavor and very costly Also the drill motors would provide more than enough power to move the robot Actually the motors will need to be limited to keep the speed at manageable levels 39 Bill of Materials Compiled by Kenneth Jemigan Description Manufacturer PIC Interface Board Tank Treads left and right assemblies 24quot Dewalt Transmission Shaft Parts for building integration Resistors 40 Preliminary Sketches Matt Spurk FrontLe The nal product will have a bumper support as shown along the front ledge Marvin will navigate environments with its treads Financial Status Kenneth J ernigan 29Oct6 5 7 7 ITotal Hours I 2675I14001200 2500I 3125 1300I 3850 16050I Actual vs Budgeted Team Expenses Donations Received FIT 20000 Total Donations 20000 Expenses to Date none 000 Total Expenses 000 Total Bud get 20000 42 Appendix 1 Current Business Plan Top Level Description With the increasing power of computers the complexity of tasks that are becoming routine is also increasing Computers are now expected to make more decisions without human interaction In the past machines simply performed repetitive tasks without monitoring the environment around them Now with increased processing power and sensor accuracy machines can react and interact with their surroundings This concept is leading to a new autonomous class of robots and machines These new robots can be assigned a task by a user and then released The control system of the robot will have the power to recognize problems and obstacles in its path through sensor inputs and the processing power to circumvent them without further user interaction Marvin will be such a robot capable of moving from one location to another avoiding obstacles between it and its destinations with minimal instruction by the user Our robot will be a crawler that uses a combination of brains and brawn to recognize and react to potential obstacles in its path while maintaining and accomplishing its overall task assigned by the user Practical applications for Marvin are numerous Marvin can be used in a corporate or home setting as an autonomous delivery vehicle The vehicle will be cost saving as it requires minimal human instruction to operate Also the robot can be mechanically modi ed to access places not easily accessible to humans such as crawl spaces and other tight areas With proper shielding Marvin can also be used in areas dangerous for humans such as high voltage or radioactive environments For the military the uses are equally versatile A crawler particularly a small model can travel inconspicuously through hostile territory Adding reconnaissance equipment to the robot will provide valuable information about the area without excess risk to human life The crawler is also cheap and expendable at least compared to human life and so would be ideal for use with ordinance disposal Our model will show the basic functionality of the obstacle avoidance system The user will provide a destination and Marvin will move there avoiding or overcoming any obstacles within its path It will include basic sensor inputs necessary to find the obstacles but will have the capability of adding specific functionality at a later date It will respond to generic and specific instructions by the user through a control laptop and will seek to complete the task until all options have been exhausted Preliminary Speci cations Marvin will be an autonomous robot capable of arriving at specified GPS coordinates Marvin will also recognize and avoid obstacles in its path during travel Operation of the vehicle can be divided into several sections of operation Central to the robot will be a primary microcontroller responsible for control The obstacle avoidance algorithm will both be processed here This microcontroller will communicate to subprocessors for data input Each of these subprocessors will be responsible for controlling and monitoring a separate subsystem such as sensors motor control etc Ai The user interface to Marvin will be provided through a control application running on a separate laptop This application will provide a graphical interface that allows the user to specify a target destination The user will also have the option of specifying specific directions to the robot such as turn left move forward etc These commands will then be transmitted to robot unit for execution No obstacle avoidance or path calculations will be performed on the control laptop Sensor data will not be provided to host laptop except for current location and heading of the crawler for use in drawing the charts The link between the control application and the autonomous robot unit will be a two way wireless RF connection which will transmit a message containing the commands as provided by the user The crawler unit will acknowledge these command will also be capable of supplying current location and heading in response to a request from the control laptop Several sensors will be located on the robot unit A GPS Global Positioning System and a digital magnetic compass will be included for determining current location and heading The GPS will have the highest resolution available under our budget The magnetic compass will be a standard unit of average resolution For obstacle avoidance the robot will have a ultrasonic unit an infrared sensor and a contact bumper The Ultrasound unit will be the primary method for finding obstacles It will provide a means for identifying large objects in front of the Marvin unit at the largest distance This data will be used to find large objects such as rocks or trees in Marvin s path so they can be avoided before contact is made The contact bumper will be placed at the critical height on the front of the vehicle to detect low objects that the wheels will not be able to clear When contact is made the bumper will provide an interrupt to the microcontroller so that the crawler can travel around the object The short distance infrared range finder will be used to monitor the path immediately in front of the vehicle This will help us avoid obstacles that are missed by the ultrasound before Marvin collides with the obstacle Product Value Proposition Autonomy in robots is a cuttingedge technology Our product will not only add to the current technology it will be capable of modifications for functionality upgrades and will server as a platform for new designs as the technology continues to develop Its adaptability will open multiple markets while using a common framework will cut development and production costs Aii Team Organization Chart Kenneth J erni gan Project Leader Status Report Compiler Brian Pridgen Kenneth Jernigan Systems Engineer Web Master Change Control Funds Locator Mark Abramovs Azhar Khayrattee Jason Haynes Brian Pridgen Microcontroller Sensor Integration Motor Control Wireless Control Machining Parts GPS Integration Matt Spurk John Ranes MAE Junior CS Senior Mechanical Design Obstacle Avoidance Aiii Team Capabilities This team is well suited for the design and implementation of Marvin The successes and failures of ART from last year give us a head start on Marvin That knowledge combined with our unique experiences makes a working autonomous robot this year a feasible project The key to Marvin will be the conversion from raw sensor data into a useful form Five of the team members are computer engineers with this kind of lowlevel experience as shown by the assembly language programming skills Two of the team members have technician experience so the physical aspects of the electronic components will be properly designed By using commercial sensors and controllers we can minimize the need for heavy electrical engineering Mechanically we are also well off for the project Our mechanical engineer has experience with building similar robots for battle competitions As such he not only knows both the theory of the design and the practicality of actually building the robot He also has a robot currently built that can be used as a test platform for the controlling systems One of our computer engineers has been properly trained to use the machine shop tools Together they will be able to build the frame and mechanical pieces for the robot necessary for the robot Programming is one of the areas that really hurt ART Our team has more programming experience including a dedicated computer scientist The computer engineers will be able to handle the lowlevel sensor interfaces as well as motor control and parts of the obstacle avoidance algorithm The computer scientist will be responsible for the high level of the obstacle avoidance and the controlling program By choosing people who are quali ed for the tasks we should minimize unnecessary frustration and delays while waiting for team members to climb the learning curve The team is strong administratively too Our project leader was a project leader for CSE 2410 which involves a massive eightweek software project That project required proper development procedures to be followed and heavily documented The project leader has experience from the software project in management scheduling and team coordination The team also has a lot of combined web design experience This along with the experience of ART last year should make fundraising an easier task Individual Strengths Mark Abramovs Computer Engineer 2 years experience UnixLinux System Administrator including networking Programming experience in C including graphical user interfaces Programming experience in PHP Programming experience in JAVA Programming experience in HTML Programming experience in MySQL Programming experience in Shell Scripting Programming in assembly language MC 68000 Programming in assembly language Intel 8051 Completed Science and Technical Communication course Aiv Jason Haynes Computer Engineer One summer experience as a computer technician Programming experience in C Programming in assembly language MC 68000 Familiar with Linux Red Hat One summer Machine shop training Machine shop certi cation green badge Programming experience in HTML Kenneth J emigan Computer Engineer Microcontroller Programming on the Motorola MC68000 and Intel 8051 Completed Programming Language Concepts course Project Lead of Software Engineering s Email Project Experience speaking to large audiences Completed Science and Technical Communication course 378 GPA Azhar Khayrattee Computer Engineer Microcontroller programming on the Motorola MC68000 and Intel 8051 Completed Scienti c and Technical Communication course C programming experience Completed Computer Communications course Linux programming experience SuSE amp Redhat Programming experience with HTML Programming experience with Apache Programming experience with MySQL 383 GPA Brian Pridgen Computer Engineer Strong technical writing skills from creating design documents and test procedures during summer internships Strong in softwarehardware interfacing from developing and maintaining a self diagnostics application during summer internships High school internship working with autonomous surf vehicles at Naval Coastal Systems Station Two summers experience as an electronic technician Two summers experience as a software engineer Programming experience in C including graphical user interfaces and serial and network communications 0 Programming experience in assembly Motorola 68000 and Intel 8051 microcontrollers o 395 GPA John Ranes 0 Computer Science and Applied Mathematics Senior 0 Experience with multiple languages 0 Java 0 CC 0 Visual Basic VB Script 0 J avaS cript 0 Visual FoxPro 0 HTML 0 Currently enrolled in Introduction to Arti cial Intelligence 0 Extensive knowledge and experience with complex algorithms 0 Testing and troubleshooting software Matthew Spurk 0 Mechanical Engineer o 2 years robotic experience 0 Welder 0 Basic machining 0 Experience in motor torquespeed calculations 0 Host of robotics competition 0 Programming experience in Fortran 0 Programming experience in C Competitive Analysis Strenth Weaknesses Opponunities Threats ART 7 Included Sensors By eliminating Our lack of Autonomous sophisticated required image vision sensor Robotic camera for heavy data processing we will lead to less Transport detailed processing can be less sophistication environment power draw complex with a analysis working product Mars Rover Essentially High cost We can create a More design Spirit unlimited makes this lowercost base and features budget Very unit unit for wider could expansive unfeasible for commercial completely data collection general application overwhelm commercial Marvin if they use commercialized their robot Avi Strenth Weaknesses Opportunities Threats MAR 7 Mobile Used Handy Poor Used IR sensor Full 360 degree Autonomous Board which electrical for close view will allow Robot is designed for design wiring proximity for advanced robotic very chaotic detection instead obstacle projects and is of contact avoidance programmed bumper no in interactive actual contact necessary to trigger ARIEL 7 Stores a map Unable to Keep track of Keeping in Autonomous of previously handle current location depth map Robot for covered anything but base on own would make the Integrated ground to aid the smoothest mapping system obstacle Exploration and with obstacle terrain not sensor GPS avoidance Localization avoidance input algorithm more ef cient Risk Analysis As shown by the current state of the ART robot a certain amount risk exists in this project Fortunately we can learn from their mistake and modify our expectations to more realistic goals In technical risks ART s primary problem came with correctly analyzing the images coming from their parabolic image The vision capability of ART was the greatest consumer of nancial and time resources for that team Therefore we are choosing not to include a visual sensor on the Marvin project Another issue the ART team had was the inability to process incoming sensor data at a fast enough rate By simplifying the sensor array on the vehicle we should be able to reduce the required processing time for sensor data Only the SONAR and the GPS data will require heavy processing The contact bumper and the moisture sensor should be discrete inputs The magnetic compass and the accelerometer should provide digitalized analog data which just needs to be limit checked By minimizing the data processing the microcontroller is freed up for more obstacle avoidance computations ART also had nancial and schedule limitations Marvin will face these same problems particularly since our project is new and only one team member took Junior Design The project schedule will be demanding with almost no slack time Each team member will have to work on multiple tasks to make sure everything is completed on time On the nancial side our project can draw from the experience of ART last year and hopefully nd the funds faster this year by going straight to those who have shown their generosity in the past Aside from ART we have several other weaknesses as well While team members were chosen very selectively the project still has risk associated with the mechanical and programming aspects of the program The Mechanical Engineer is a junior and has the option of leaving at any point since he is not receiving credit for the class Also we have only one computer scientist He is wellquali ed for working with the obstacle avoidance algorithm but has very little C GUI experience One of our Computer Engineers has enough GUI Avii experience to create a basic interface but another Computer Scientist with GUI experience would enable us to create an ideal interface with high easeofuse The GPS might also provide problems Under the current budget it will be difficult to find one that works to the accuracy desired that also has a robust interface for communication with the microcontroller The selected GPS unit will have to be a balance of speed accuracy and interfacing ease The obstacle avoidance algorithm may also be an issue Obstacle avoidance is still a developing technology Balancing the sensor input to correctly respond under different situations will require heavy experimentation to determine the right combination If the development of the algorithm is not properly controlled it could become the resource consuming aspect of the project not leaving enough time for proper system integration and testing OutOfBounds Situation Project Impact Unable to obtain sufficient funds for high resolution sensors Greater amounts of error will be incorporated into the operation of the robot If the fund is significantly short various sensors may have to be eliminated leading to a redefinition of an obstacle E g water avoidance may be removed from the functionality Our obstacle avoidance algorithm does not function acceptably The algorithm will have to be reworked entirely If this is the case time constraints will require that the algorithm also be greatly simplified to cut development and testing time Needed components are not available If any of the sensors are backlogged or out of production the design of the entire system will have to be reworked Motors draw an unacceptable amount of current If the motors overload the batteries of the robot smaller motors or larger batteries will be needed These changes will create a ripple effect leading to both hardware and software changes Sensors do not perform to specifications in resolution interface or power consumption Higher quality sensors will be needed or the controlling system and algorithm will have to be modified to support the limitations of the sensor This may lead to poorer performance by the robot Aviii