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The Design Process
Mr. Christopher BeardenPatriot Systems [email protected]: @C_Bearden321-777-2369
FRC Team 1592
Bionic Tigers
For
Video Presentation
If you would like to watch a video of this presentation, please
click on the following link :
The Design Process Video
Purpose
• Describe the engineering process used
by industry
• Relate the engineering process to the
FRC
Developing a System5 Major Phases
Analysis Design Build Test Support
• Requirements Analysis
• Strategy
• Detailed Design
• Preliminary Design
• Integration
• Fabrication
• Design Testing
• Validation
• Upgrades
• Defects
= Design Reviews
Ideas Prototypes Finished Product
What will be our execution strategy for this work?
Analysis Design Build Test Support
Specialities
1. Mech Eng - Pneu, Propulsion, Fluids
2. Software Eng - Operating
Sys, Algorithm, Embedded
3. Elect Eng -
Radar, Power, Communications
4. Architects
5. Chemical Engs
6. ……..possibly many more!
Staffing
1. Who is available?
2. Do employees have the
necessary experience?
3. Should we hire someone?
4. Should we give some work
to another company?
Location of Work
1. Where will the work be performed
(U.S. Or Overseas)?
2. Do we adequate facilities at those
locations?
Tools & Equipment
1. Software – Lab View or C++
2. Engineering – Pro E or Autodesk
Inventor
3. Machine shops
4. Electronic manufacturing
Development
Process
1. Design reviews
2. Parallel activities
3. Schedule
Roles & Responsibilities
1. How are we organized to
execute the work?
2. Who is in charge of who?
3. Who is responsible for what?
Execution
Strategy(Program Plan)
Types of Requirements
Sources of
Requirements
Functional Performance Physical Interface Services
1. Customer
Specifications
2. Marketing
3. Safety
Standards
4. Meetings
5. Company Stds
6. Industry Stds
What must this product do?
How well must it perform this task?
What size,weight, color
must it be?
How will people useit? What
makes it work with other products?
Besides the product, what else
must be delivered (training,
documents,
maintenance,
etc.)?
1. Game Rules
2. Team Strategy
3. Robot Manual
4. Awards
5. Arena
6. Meetings
Same Same Same Same Same
Analysis Design Build Test Support
What are we supposed to be building?
Industry
FIRST Robotics Competition
Analysis Design Build Test Support
Examples of Requirements
1. Minibot must ascend a metal pole and impact a
sensor disk. (Functional)
2. …..must climb the tower < 10 seconds
(Performance)
3. Sponsors logo’s will be displayed on HostBOT
(Physical)
4. A driver station will be used to control the HostBOT
(Interface)
5. HostBOT will not cross the vertical plane of an
opponents zone (Services – Operator Training)
What are the major pieces of our robot system?
Analysis Design Build Test Support
ROBOT “System”
Operator
Driver Station
Host Bot
MiniBot
Launcher
Chassis
Manipulator
MiniBot
Block Diagram
“System” implies people, equipment
and documentation
Need a design concept to
get started
What are the ALL the pieces of our robot system?
Analysis Design Build Test Support
Breakdown
Diagram
Requirements Brainstorming
Analysis Design Build Test Support
• Technical teams meet to define the requirements for subsystems and assemblies– Functional– Performance– Physical
– Interface
• Example1. The D/S allows an operator to control the HostBOT - Given
1a. There will be touch sensitive slider control to vary the HBOT speed from 0 to MAX – Brainstorming Session
• Assign responsibility for requirements• Software
• Mechanical
• Electrical
• Allocate requirement to the design• Which Subsystem or Assembly does this belong to?
Preliminary Design Goal: Identify and assess alternatives for each of the ROBOT subsystems (D/S, MiniBOT, etc). Choose one.
Analysis Design Build Test Support
Step 1: Technical teams meet to propose solutions to the design problem.
Example: MiniBOT Design Concepts
Alternative #1: Use magnetic force to attach MBOT to the metal
tower and propel it upwards with an electric motor to impact the disk.
Alternative #2: Use a spring-loaded mechanism that clamps the
MBOT to the metal tower when the MBOT impacts the tower.
Step 2: Evaluate the alternatives.
Step 2a. Test the concepts using a mock-up or a model.
Analysis Design Build Test Support
Example: Alternative #1 Mock-Up
Tape magnets to wood chassis; attach wheels; size it for the tower.
Knowing that the MBOT will need a motor, wheels, battery pack – find that
weight and add it to the mock-up – say 5lbs.
Test 1: What # and weight of magnets would it take to hold 5lbs
upright against the tower?
- How does this change as weight is added?
Test 2: How close to the tower must the magnets be?
- How does this change as distance changes?
Test 3: Do magnets affect the operation of the electric motor?
- What separation distance is needed?
Test 4: Will the MBOT travel in a straight line up the tower?
- How could this be corrected?
Analysis Design Build Test Support
Step 2b: Consider the design constraints
a. Volume of MBOT is restricted to 12” x 12” x12”
b. MBOT must not weigh more than 15lbs
c. No more than 2 motors
d. Powered only by 12VDC battery
e. Allowed materials
Step 2c: What are the risks of this approach?
Ex: What if ……..the
MBOT falls off the tower
after impacting the
upper disk?
Can this risk be
mitigated somehow?
Analysis Design Build Test Support
Step 3: Compare the alternatives
Alt #1 Alt #2 Alt #3
Performance 4 secs 5 secs 9 secs
Risk High Medium Low
Cost $ 100 $ 500 $100
Color Criteria:
Performance: if time <= 5 secs (Green)
>5<= 10 secs (Yellow) >10 secs (Red)
Cost: <= $100 (Green)>$100 <= $400 (Yellow)> $400 (Red)
Step 4: Select an alternative
Analysis Design Build Test Support
Step 5: Add design-level requirements to the existing requirements.
Example: Add what was learned from testing the
mock-up.
Step 6: Create a Preliminary Layout Diagram
Motor
Gears
BatteryPack Magnets
Wheel
WheelWheel
Wheel
Kill
Sw
12” max
Detailed Design Goals: Identify specific parts and materials. Specify how these parts interact.
Analysis Design Build Test Support
Step 1: Identify the mathematical word problems and solve them.
Example: What gear design will propel a 5 lbs MBOT up the tower
at a speed of X inches/second using an electric motor with an output
power of……..a rotational speed of ……..and 4” diameter wheels?
Step 2: Identify parts
- Consider the design constraints from the Robot Manual
- Make it or buy it?
-- Cost limits imposed by FRC ($400 per part)
-- May need a detailed drawing if “make”
- Add parts information to the “Breakdown Diagram”
- Are there any “long lead” parts?
Analysis Design Build Test Support
Step 3: Design the interfaces
What SW or HW must be added to the design to make the pieces
fit and function together ?
- HOSTBOT
-- Manipulator Assy
-- Chassis Assy
-- MiniBOT Launcher Assy
-- MiniBOT Assy
Step 4: Create the drawings and digital models
- Layout Drawings
- Electrical Schematics
- Fabricated Parts
The Build Phase Goals: Have a completed Robot system (including SW) that isready for testing.
Analysis Design Build Test Support
Step 1: Drawings are released to machine shop (machinists, microelect, etc).
Step 2: Purchase Requests are released (a specialist in Industry).
Step 3: Transportation requirements are defined; materials are
purchased; crates are constructed.
Step 4: Parts are received and put into kits (a box or a shelf location)
Use the Breakdown Diagram
Step 5: Kits are assembled.
Step 6: Assemblies are integrated.
Manipulator Assy Kit
Chassis AssyKit
MIniBot AssyKit
MiniBotLauncher Assy Kit
The Test Phase Goals: Test the performance limits of the product. Verify the product meets the customer’s original set of requirements .
Analysis Design Build Test Support
Developmental Testing
- How fast, how high, how far?
- Determining the safety limits
- Breaking points
Validation
- Prove to the customer that the product meets or exceeds
their original requirements
- Product ships when the customer is satisfied
The Support Phase Goals: Design new features for a fielded product. Fixing defectsthat were discovered by users.
Analysis Design Build Test Support
A new feature (i.e. requirement) sends you all the way back to
the Analysis Phase!
** What’s the implication here?****
Types of defects
- Software bug
- Parts that break too often
-- Environment (heat, humidity)
-- High usage
-- Poor quality
Replacement parts (or software) no longer made
How is Software different?
Analysis Design Build Test Support
Process phases can be the same but different diagrams and products than HW.
SW development methods and tools very different than HW.- Object Oriented Design
- Architecture Development Languages
- AGILE development
- Service Oriented Architectures
Analysis
- SW Architecture (versus Block Diagram)
Design
- Adding more detail to SW architecture
- Designing the interfaces to HW items
- Designing screen layouts
- Data structures, algorithms and sequencing
Build
- Writing and deploying code
- Version control
- Completing the SW architecture by integrating its pieces
Waterfall Development Process
The Last Word
Analysis Design Build Test Support
80% of catastrophes discovered here
But they were caused here!
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design-process-final