Website should document your journey through MSD, so include work-in-progress as well as latest results. Use PDFs for display whenever possible so that information is easily viewable without the need to download files and open applications. (Your EDGE file repository should still contain original files).

## Week 9 Design Revelation

We went through several versions of actuation before we finally settled on one type. However, running simulations of our proposed system proved that our method would not work. So, we came up with a solution that works in simulation. It can be found at:Methods of Actuation

## Detailed Block Diagram

Detailed Block Diagram## Energy Flow Chart

Energy Flow Chart## Engineering Specifications to Customer Needs with Test Plans

Engineering Specifications## Engineering Analysis - Equations and Calculations

### Mechanical

- Physics of the system
- Losses due to friction
- Frame Design/Plate Selection
- Carbon fiber over foam
- Order all materials from Noah's Marine Supply
- Machine shop will cut out design
- We will lay carbon fiber and resin
- Very rigid
- Holes for plastic inserts so we do not crush foam in compression (from fasteners)

- Axle
- Assume worst case
- All torque in wheel is now in frame at time of collision
- Assume fall distance of 2 meters
- Assuming .0005 meters impact distance, frame would see 137.2 kN
- Our axle can handle (79.3e9)(pi)(.009525)^2/4 = 5650 kN in shear

- Braces
- Calculated for bending and shear of tubing

- Worst case: one frame would see 12.6 N-m or 115.5
in-lbs of torque

- Spreading that out over 5 braces, each brace
would see (12.6 N-m)/[(.3556 m)*(5 braces)] = 7.09 N
or 1.59 lbs

- This force would result in a flex of 0.0682 deg
(0.032 in) over the length of a tube

- This results in 37 Mpa of stress, but failure would not occur until over 250 Mpa

- Calculated for bending and shear of tubing
- Fastners

### Electronic Off-Board Storage

Storage ComparisonBetween 2 Mb and 144 Mb needed (2Mb for 1 60-second long trial with 10 16-bit inputs at 500Hz and 144Mb for 30 trials of 60 seconds with 10 16-bit inputs at 300Hz)

The verdict: On-board storage of microcontroller and development combined not enough for even a worst case scenario. Off-board storage is needed.

### Timing Diagrams

#### Single-step Analysis

Periodic motion from MATLAB simulation. All quantities are scaled by their maximum value.A close up view of the periodic motion during one cycle. All quantities are again scaled by their maximum value, except for the total energy, which is plotted as a percent change from the initial energy.

A close up view of the actuation. All quantities are again scaled by their maximum value, except for the total energy, which is plotted as a percent change from the initial energy. The effect of actuation can be seen in the linear increase in the total energy of the system.

A close-up view of the collision. All quantities are again scaled by their maximum value, except for the total energy, which is plotted as a percent change from the initial energy. The discontinuities in all quantities are due to the collision.

#### System Delay

link to simulations/calcs## Simulations

### MATLAB parameter simulations

Current Prototype Parameter Values | Proposed System Parameter Values | Units of Parameter | |
---|---|---|---|

Number of spokes | 5 | 5 | Quantity |

Length of legs | 0.4064 | 0.41656 | m |

Mass of frame | 0.737 | 1.5 | Kg |

Inertia of frame | 0.021 | 0.066 | Kg m^2 |

Mass of inertia wheel | 0.9108 | 1.25 | Kg |

Inertia of inertia wheel | 0.00723 | 0.112 | Kg m^2 |

k-value of spring | 3 | 5 (10.88) | N m / rad (lbs/in) |

## Drawings and Pictures

### Mechanical 3D diagrams

#### Frame Design/Plate Selection

#### Axle

#### Braces

#### Fastners

#### Plate Fabrication Trial

Plate Fabrication TrialIn case the above link doesn't work:

/public/Senior Design 1/Plate Fabrication Trial 2012-11-16.pdf

### Electrical Systems

#### TI LaunchPad

Microcontroller Development board:#### Batteries

#### Sensors

- miniature optical encoder (attached to motor)

### Schematics

#### Microcontroller setup

- TI LaunchPad of F28027
- NOTE: TI SCHEMATIC!!
- TI SCHEMATIC

- Sensors to Microcontroller
- Pending

- Microcontroller to Driver & H-Bridge
- Pending

- Batteries

## Motor Control Algorithm

- Implementing the control algorithm in software

Control Algorithm Block Diagram

### Block Diagram of Algorithm

## Bill of Materials (BOM)

Tentative Bill of Materials - Googledoc Spreadsheet## Risk Assessment

Probability & severity on 1 - 3 scale, where a "3" rating in both cases means very likely and we are totally screwed, respectively.Description | Probability | Severity | Risk Factor | Mitigation/Prevention Strategy | Watchdog |
---|---|---|---|---|---|

Illness/time consuming obligations | 3 | 2 | 6 | Do not rely upon having time in the future to accomplish task | All |

Materials unavailable & long lead times | 2 | 3 | 6 | Determine parts orders as far in advance as possible. Where applicable, have alternative vendors lined up. | Owen |

Lag time of system from data collection to movement | 2 | 2 | 4 | Compile very accurate system timing diagram by reviewing each parts' delay and minimize delays where possible. | Maddy |

Real life does not match up with simulations and theoretical data (includes if actuation will actually work or not & general theory -> physical) | 3 | 3 | 9 | Run as many simulations as possible, double-check work, get as many professional opinions as possible before diving into system realization. | Hao |

Cost v.s. quality | 2 | 3 | 6 | Determine minimum requirements for quality | Owen |

Proper distribution of weight | 1 | 2 | 3 | Wise placement of devices | Dan |

Ability to obtain motor at all/in time | 3 | 3 | 9 | Keep looking, ask for help if needed | Becky |

Complete structure breakage (mistake, breaks during tests) | 1 | 3 | 3 | Design system (choose materials) to be strong | Owen |

## Detailed Design Review

DDR PresentationPre Read Package

## Beginning of SDII

Shared Vision for week 3 of MSDII

Home | Terminology | Planning &
Execution | Systems Design | Build, Test,
Document | Photo Gallery