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System. Design Review. Mason Verbridge Evan McNamara Steve Fleischmann Artem Sivak. P11032. Outline. Objectives Work Breakdown List of Customer Needs System Specifications Concept Selection Flow-down Concept Selection Matrices Form Factor / Concept Topologies
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System Design Review Mason Verbridge Evan McNamara Steve Fleischmann ArtemSivak P11032
Outline • Objectives • Work Breakdown • List of Customer Needs • System Specifications • Concept Selection Flow-down • Concept Selection Matrices • Form Factor / Concept Topologies • Alternative Usage Layouts • Benchmarks and Input • Going Forward • Wrap-up
Objectives Obtain input and direction (from all stakeholders) regarding the process and selection of a final concept, as well as suggestions on our current form factor.
Initial Needs Outlined With Customer Needs Prioritized and Refined by Customer. Moves PowerPoint to "Next" or "Previous" Slide Hands Available for Signing Upper Body Mobility Quick and Intuitive to Operate Viable Classroom Range Lightweight / Unobtrusive Durable Cost-Effective Good Battery Life No False Triggers Customer Needs Priority High Low
Specifications were developed to meet and/or exceed customer needs. Each specification is quantifiable and testable Actual test plan / test specification to be constructed at a later date Device weighs under 0.5 pound User Maintains Full Range of Motion Device is of Minimum Size Device Survives Drop Test of 0.75m User is not Hindered From Performing ASL Device Produces No False Triggers Device has 40ft. Minimum Range Project Completed Under Budget Device Has a 2 hr. Minimum Battery Life Device Does Not Interfere With Other Classroom Devices (RF) Device has a latency of Less than 0.75seconds Device is One-Size-Fits-All Device Successfully Advances to the "Next" or "Previous" Slide Instructions to Operate is less then 10 steps System Specifications
Benchmarks, Input, and the Bottom Line • David M.- “Right now I usually have someone else press the "next" button but it gets annoying having to give them a cue, not to mention it detracts from the smoothness of the presentation. This is of course unless the "button presser" is a teammate I've practiced with and they know WHEN to click- and in that case it’s not always perfect since when I'm spontaneous and add more information than we had rehearsed they may mistakenly jump ahead to the next slide.” • Avi H. – “If it's the size and weight of a watch, it won't hinder my signing at all.” • Adam N. – “I've never presented an entire presentation in ASL because I've always talked… Lately, I've been signing a lot more and trying not to talk as much either… A wristband actually sounds extremely nice.” • Greg B.– “Currently, there are two ways I can do a presentation. 1) Have a volunteer stand at the computer waiting for my signal to change the slides. 2) Pause at every slide to change it myself, either using the computer or picking up a wireless remote. It would definitely be nice to streamline the experience. [ A wristband] would work very well, and would not be distracting as long as the profile is small/slim.” • Emily S.– “[A wristband would work] since I pretty much always have something on my wrist no matter what.” • It’s clear to see that implementing a wrist-based solution would be highly useful to ASL users!
Form Factor Thus far four basic layouts have been examined. They are as follows...
Concept 1 Pros: • Out-of-the-way side- mounted switch Cons: • Possible interference with clothing • Size (depth of switch) • Left vs. Right hand interference
Concept 2 Pros: • Intuitive Cons: • Possible False Triggers • Requires finger dexterity
Concept 3 Pros: • Quick trigger method • Intuitive • Usability for dexterity impaired Cons: • Possible False Triggers • Switch Sensitivity • Size (depth of switch)
Concept 4 Pros: • Reduction of False Triggers • Intuitive • Usability for dexterity impaired Cons: • Bulky • Moving Parts (long term reliability) • Possibly Fragile
Possible Feature Expansion • Features may be added, at the expense to overall device size • Feature selection will be driven by customer input • Laser Pointer • Start Presentation Button • Mouse Control • Volume Control
Alternative Usage Surfaces A ‘C ‘B B C
Thoughts and Discussion • Likes? • Dislikes? • Comments? • Concerns?
Recap • Concept Discussion Overview • User Interface Discussion Overview
Going Forward • Gantt Chart / Project Plan (Appendix D) • Feasibility Studies • Test Plan • Prepare for week 9 design review • Risk Assessment (Appendix C)
Power Consumption Assumptions & What We Know • System will only work down to 2.4V. (No noticeable fall-off in testing up to this point) • The system is constantly drawing 10mA of current – a vast safe margin. • The above makes it clear that the unit is continuously utilizing 30mW of power. • Minimally sized watch/hearing aid batteries estimate a lifetime of 150 mili-Amp Hours. • This means that even an extremely small battery will give us 15+ hours of usability! What We Have • System Runs on 3V, provided via two AAA batteries. • Testing has shown that the unit will run without major issue until approximately 2.2V. (Laser pointer begins to dim, but no other effects) • Further analysis shows that the unit will consume a maximum of ~7mA. • Max current condition occurs on button press when laser pointer is active. • Idle system consumes current on the order of µA.