4/28/2004Optical Tape Measure Optical Tape Measure May Team Members: Faculty Advisors: Nick Freese (EE) Dr. Aleksander Dogandzic Bruce Fu (EE) Dr. Degang Chen Jason Thompson (CprE) Client: Eugene Zimmer (EE) Senior Design

4/28/2004Optical Tape Measure Presentation Outline Introduction Project Activity Description Resources and Schedules Closing Materials

4/28/2004Optical Tape Measure Definitions Laser Driver: a device used to generate a specified pulsed output voltage to a laser Photodiode: semiconductor that produces current as a result of the absorption of photons Resolution: the speed of our designs time to digital converter

4/28/2004Optical Tape Measure Introductory Materials Problem Statement Solution Approach Operating Environment Intended Users and Uses Assumptions and Limitations End Product

4/28/2004Optical Tape Measure Problem Statement Standard tape measures are cumbersome Difficult to use in complex environments Ultrasonic devices have limited capabilities

4/28/2004Optical Tape Measure Solution Approach Design an optical tape measure Laser guided to designate the exact point of measurement

4/28/2004Optical Tape Measure Environment and Users Operating environment considerations –Possible indoor and outdoor conditions –Physical abuse such as dropping Intended Users –General home owners –Construction workers –Surveyors –Architects

4/28/2004Optical Tape Measure Intended Uses General measurement Surveying Mining Recreational sports Industry

4/28/2004Optical Tape Measure Assumptions and Limitations Assumptions –The object points to be measured are stationary –The reflecting surface will be sufficiently reflective and nearly perpendicular to the incident pulse Limitations –Device must measure up to 100 feet –Accuracy must be within ± 0.5% –Dimensions must not exceed 6” x 8” x 3” –Cost of the prototype must be less than $355 –Device must be easily portable

4/28/2004Optical Tape Measure End Product End product description –A small, durable, lightweight optical tape measure –A user’s manual –A maintenance manual –Test results

4/28/2004Optical Tape Measure Project Activities Accomplishments Definition Activities Approaches Considered Design Overview Implementation Activities Testing

4/28/2004Optical Tape Measure Accomplishments Defined project specifications Researched various technologies Ordered necessary circuit components Created an error model of the distance versus timer count Nearly completed device functionality testing Partially completed module integration testing

4/28/2004Optical Tape Measure Definition Activities Two initial issues –Distance between two points or from the device –Interfacing with a computer to create a model of a room or building

4/28/2004Optical Tape Measure Approaches Considered Possibilities –Pulse Time of Flight –Modulated Beam Systems –Triangulation

4/28/2004Optical Tape Measure Triangulation Advantages –No high frequency timer or phase detector –Overall more simple –Less Expensive Disadvantages –Less accurate –Requires at least two lasers –Setup cumbersome and inadaptable

4/28/2004Optical Tape Measure Modulated Beam System Advantages –No high frequency timer –Fewer systematic error possibilities Disadvantages –A high frequency modulator is needed –Less accurate at farther distances

4/28/2004Optical Tape Measure Pulse Time of Flight Advantages –More accurate at farther distances –More information readily available –Times could be averaged over several pulses Disadvantages –Requires a high frequency timer –Slightly more expensive –Ambient light could be problematic

4/28/2004Optical Tape Measure Design Overview Microcontroller Timer TransmitterDisplay Receiver Button Start Stop Distance ≈ 3 * 10 8 m/s * 3.28 ft/m * time

4/28/2004Optical Tape Measure Implementation Activities Concerns –Resolution –Rise and fall times –Laser output power and pulsing capabilities –Optimal receiver wavelength –Operating voltage

4/28/2004Optical Tape Measure Implementation Activities Time to digital converter DEI laser driver

4/28/2004Optical Tape Measure Implementation Activities OSRAM pulsed laser diode and photodiode PIC microcontroller LCD display SPL PL85SFH 203 PFA

4/28/2004Optical Tape Measure Testing Activities Functionality Tests –Individual modules –Module integration –Final system Error Analysis Tests –Accuracy –Environmental effects

4/28/2004Optical Tape Measure Resources and Schedules Personnel Effort Other Resources Final Project Costs Schedules

4/28/2004Optical Tape Measure Personnel Effort Team MemberHours Freese, Nick161 Fu, Bruce155 Thompson, Jason157 Zimmer, Eugene153 Total626

4/28/2004Optical Tape Measure Personnel Effort

4/28/2004Optical Tape Measure Other Resources

4/28/2004Optical Tape Measure Final Project Costs ItemsCost Poster$68.00 Laser Driver$ Electronic Components$69.79 Sub Total$ Labor at $10.00 per hour Freese, Nick$1610 Fu, Bruce$1550 Thompson, Jason$1570 Zimmer, Eugene$1550 Total$

4/28/2004Optical Tape Measure Schedules Tasks Sept.Oct.Nov.Dec.Jan.Feb.MarchAprilMay Project Definition Technology Research Final Design Implementing Testing Documenting & Reporting - Planned - Actual

4/28/2004Optical Tape Measure Closing Materials Project Evaluation Commercialization Recommendations for Additional Work Lessons Learned Risk and Risk Management Summary

4/28/2004Optical Tape Measure Project Evaluation Problem Definition (Fully Met) Research (Fully Met) Technology Selection (Fully Met) End Product Design (Fully Met) Acquire All Parts (Fully Met) Product Implementation (Partially Met) Testing and Revisions (Partially Met) Documentation (Fully Met)

4/28/2004Optical Tape Measure Commercialization Capable of being fully commercialized Production Cost: $264 Street Cost: $343 Possible market –Forestry, Surveying, Construction Replace inaccurate ultra sonic measuring devices.

4/28/2004Optical Tape Measure Additional Work Commercialized version requires –Working prototype –Increased functionality –Cost optimization

4/28/2004Optical Tape Measure Lessons Learned Successful Project –Project Plan –Poster –Design/Final Report Things to do differently –Ordering parts –Second semester communication –Plan more time for implementation

4/28/2004Optical Tape Measure Lessons Learned Technical Knowledge Gained –Microcontroller use –LCD control –Lasers and photodiodes –Time to digital converter Non-Technical Knowledge Gained –Communication importance –Time management considerations

4/28/2004Optical Tape Measure Risk and Risk Management Anticipated Risks –Project Management Kept communication lines open Stuck to the project plan –Member Attitudes Addressed problems early –Product Risks Chose safe laser Cut expensive parts

4/28/2004Optical Tape Measure Closing Summary Problem –Ultrasonic Tape Measures –Inaccurate, hard to use Solution –Optical Tape Measure –Time of laser flight –Accurate measurement

4/28/2004Optical Tape Measure Questions? Optical Tape Measure May 04-30