1. P14372 Actively Stabilized Hand-Held Laser Pointer
Kaitlin Peranski
Spencer Wasilewski
Kyle Jensen
Kyle Lasher
Jeremy Berke
Chris Caporale
Kaitlin

2. Agenda Problem Definition Review Executive Summary System Review
Detailed Design Review
Detailed Risk Assessment
Test Plans
Bill of Materials
Cost Analysis
Project Plan for MSD II
Kaitlin

3. Problem Definition Review
Kaitlin

4. Problem Definition
There are many people today who use laser for various applications: to aid in presentations, medical imaging, and defense. Under many use scenarios they are negatively affected by unwanted vibrations; one such example is a nervous presenter using a laser pointer. New Scale Technologies (NST) has developed a module that steers a laser beam using piezoelectrics and mirrors. Currently they cannot actively detect and compensate for hand vibrations. To reduce this gap, a handheld and user friendly unit is to be developed utilizing the NST module. Concerns for development include: response time, operating temperature and duration, and unwanted motion attenuation.
Kaitlin

5. Engineering Requirements
Customer Needs
Engineering Requirements
Kaitlin
Focus on added test plans for each requirement

6. Executive Summary Target Frequency Range: 1-20 Hz
Cost Analysis: Total < $350
Test Bench Design: < $100
Response Time Analysis:
Required = 12.5 ms
Capability = 10 ms (worst case)
Power Consumption: 1.4 Watts
Heat Generation: Surface temperature of 95o F
Comparison of Gyroscopes and Accelerometers: Beyond 80 cm, gyroscopes are more accurate
Housing: Aluminum, 139X42X32 mm
Kaitlin

7. System Review
Jeremy

8. System Architecture
Jeremy
This shows the concept that we’ve chosen

9. Concept Selection Concept 1 Concept 2 Battery Gyroscope
Low Pass Filter
Processor
Communication to NST Module
Battery
Accelerometer
Integrator/Low Pass Filter
Processor
Communication to NST
Jeremy
Two final concepts that we considered

10. Gyroscope VS Acceleromter
Jeremy
Describe why we picked gyroscopes over accelerometers

11. Required Response Time
Highest hand jitter frequency = 20 Hz
Sample rate = 4*frequency = 80 Hz = sec
Required time = sec or 12.5 ms to accurately reduce vibrations
Chris

12. Response Time Breakdown
NST
Data Acquisition
Software Interpretation and Control
Communication to NST
Chris

13. Tested Circuit
Chris

14. Response Time Measurements
Chris
Zoomed to Zero (Delay)
Total Time

15. Total Response Time NST ~ 2 ms (worst case scenario)
Data Acquisition ~ 2 ms
Software Interpretation and Control ~ 2-5 ms
Communication to NST ~ .2 ms
Total Time = 9.9 to 10 ms
Gives 2.5 ms of overhead
Chris

16. Agenda Detailed Design Review Schematic Drawings Control Algorithm
Thermal Resistance Analysis
Device Housing/Layout
Test Bench Design
Kaitlin

17. Detailed Review
Kaitlin

18. Block Schematic: Our System
Chris

19. Gyroscope Schematic
Chris

20. Gyroscope InvenSense ITG-3200 Sample Rate: 8kHz
Operating Current: 6.5mA
Operating Voltage: 3.3V
Full Scale Range: 2000°/s
Fast Mode 400kHz I2C Interface
Simple breakout board with mounting holes
Chris

21. Power Supply and Charger
Chris

22. Battery UnionFortune 063450 Cells 1000mAh LiPo
2 cells in parallel for 2000mAh total
Battery life close to 4 hours
-25°C to 60°C Operating Temperature
Nominal Voltage: 3.7V
Maximum Current: 1A (wire limited)
Chris

23. Processor Schematic
Chris

24. Processor SparkFun Arduino Fio v3 8MHz Clock 16 Digital I/Os
6 Analog I/Os
150mA Current Draw
Built in 3.3v regulator and LiPo charger
Built in switch
I2C, SPI, USB compatible
Chris

25. Deriving the Transfer Function?
Jeremy

26. Pole Zero Map
Jeremy

27. Bode Plot
Jeremy

28. Sample Input (f = 1 Hz)
Jeremy
Green is input, Red is output

29. Control Algorithm Poll Gyro For Data (I2C) Acc = 0 Subtract Gyro Data
From Accumulator
Wait
Acc > 15?
Re-Center NST Module
Acc < -15?
Jeremy
Compute Encoder
Counts
Send to NST Module 29

30. First Control Scheme
Jeremy

31. Second Control Scheme
Jeremy

32. Simulated Jump (Within Bound)
Jeremy

33. Simulated Jump (Bound Crossing)
Delay = .1s
Jeremy

34. Simulated Jump (Bound Crossing)
Delay = .5 s
Jeremy

35. Thermal Resistance Analysis
Surface temperature of housing
𝑄=ℎ𝑆 𝑇 𝑠 − 𝑇 ∞
𝑇 𝑠 = 𝑇 ∞ + 𝑄 ℎ𝑆
Assuming hand insulating half the surface and 𝑇 ∞ =68°F
𝑇 𝑠 =95°𝐹
Kyle L

36. Thermal Resistance Analysis
Kyle L

37. Thermal Resistance Analysis
Assuming TC1=TC2=TC
𝑄= 𝑄 1 + 𝑄 2
𝑄 1 = 𝑇 𝑐 − 𝑇 ℎ𝑎𝑛𝑑 𝑅 𝑎𝑖𝑟 + 𝑅 ℎ𝑜𝑢𝑠𝑖𝑛𝑔 + 𝑅 ℎ𝑎𝑛𝑑 = 𝑇 𝑐 − 𝑇 ℎ𝑎𝑛𝑑 𝑅 1
𝑄 2 = 𝑇 𝑐 − 𝑇 ∞ 𝑅 𝑎𝑖𝑟 + 𝑅 ℎ𝑜𝑢𝑠𝑖𝑛𝑔 + 𝑅 𝑎𝑡𝑚 = 𝑇 𝑐 − 𝑇 ∞ 𝑅 2
𝑄 1 = 𝑅 2 𝑄+ 𝑇 ∞ − 𝑇 ℎ𝑎𝑛𝑑 𝑅 1 + 𝑅 2
𝑄 2 = 𝑅 1 𝑄− 𝑇 ∞ + 𝑇 ℎ𝑎𝑛𝑑 𝑅 1 + 𝑅 2
Kyle L

38. Thermal Resistance Conclusions
Top surface = 96°𝐹
Bottom surface (surface with hand) = 97°𝐹
Temperature at surface of chip = 117°𝐹
Kyle L

39. Device Housing: Shell
Spencer

40. Device Layout: Side View
Spencer
This needs to be replaced with updated diagram

41. Device Layout: Side View
Spencer

42. Device Layout: Side View with Screws
Spencer

43. Device Layout: Top View
Spencer

44. Device Layout: Bottom View
Spencer

45. Device Layout: Rear View
Kyle J

46. Device Layout: Front View

47. Wiring Diagram: Test Bench
Kyle J

48. Test Bench Design
Spencer

49. Test Bench
Spencer

50. Test Bench
Spencer

51. Test Bench
Spencer

52. Test Bench
Spencer

53. Test Bench
Spencer

54. Agenda Detailed Risk Assessment Test Plans Bill of Materials
Cost Analysis
MSD II Project Schedule
Kaitlin
Any questions before moving forward?

55. Detailed Risk Assessment
Kyle J

56. Test Plans Validate control algorithm code
Validate gyroscope within device
Verify test bench functionality
Calibrate test bench using second gyroscope
Confirm battery life and heat generation
Confirm surface and chip temperature
Kyle J

57. Cost Analysis
Kyle J

58. MSD I Project Plan
Kaitlin

59. MSD II Project Plan
Kaitlin

60. THANK YOU!

61. Appendix

62. Housing Drawing

63. Housing Drawing
Put each on their own slides

64. Housing Drawing

65. Housing Drawing