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    Design Review

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    The Design Review process occurs in several stages and increasing levels of detail.  Each of the stages described below is used to help give feedback to groups and highlight issues and problems that may occur during design and fabrication.

     

    Every group will be proposing different solutions, and different instructors and TAs will highlight different areas of concern (occasionally conflicting with one another!)  Part of the experience of the course is to learn to listen to constructive comments from a variety of sources and learn to judge the relative importance of each part of feedback by the course instructors.


     

     

     

    1.  Informal Pre-Review

    • 10-15min discussion with at least 2 course instructors.
    • Any time during Lab 4 or week 1 of  Lab 5
    • can (and should!) be done multiple times, if possible, to review your ideas as you work on them in prep for the Formal Discussion.


    Expected:

    • Overall:   Verbal overview of general robot function
    • Mechanical:   Sketches of primary mechanical mechanisms
    • Electrical:   Primary sensor and motion systems, block diagrams showing major electronic circuits
    • Software:    Primary operational/software flowchart diagram
    • Resources:   Major technical resources required (# and type of motors, types of sensors, linear stages/arms, items not supplied in lectures)

    Outcome:

    • With the help of TAs/instructors, identify the major problem areas to address for the Formal Review, including:
      • Areas on the robot with the highest probability of issues with mechanical alignment, robustnes, repeatability, etc…
      • Motor control and sensitivity issues
      • Electronics difficulties
      • Sensor difficulty
      • Difficulty in programming and algorithm development

     

    2.  Formal Discussion

    • 10 min presentation, followed by ~45 min discussion
    • scheduled with instructors in mid-June.

    Expected:

    • Mechanical:    Printed / hand drawn version of major mechanical components and method of mounting key components together.
    • Electronics:    Block-diagram of overall system showing major connections and block diagrams of wiring connections between PCBs and components.  Electronic schematics for individual PCB’s.
    • Analysis:         Calculations for motors, torques, speeds, results of small-scale tests to verify operation – convince us and yourself that your design will work as specified.
    • Risk Assessment:  Identification of the biggest risks/obstacles for your design during fabrication and operation.
    • A rough draft of all discussion material is adequate, provided that all relevant information is available for dicussion, and in preparation for the . .
    • You should emphasize the application of engineering theory to your design.   Show calculations and estimates wherever applicable.
    • If calculations or experiments are missing you can expect to be asked to do them on the spot

    Areas of Discussion for Formal Review / Design Document

    (note that all of the content does not have to be discussed in this order, but all material is expected to be known by the group and may be discussed during the Formal Design Review)


    1. Overview of basic strategy.
      1. Calculations of round trip time, and estimated time/score achieved by the Robot
      2. Most likely sources of issues and problems in strategy.
      3. Location of critical elements on the robot (wheels, arms, sensors, etc)
    2. Chassis
      1. Listing of each chassis component
      2. Areas of chassis design which allow for flexibility during performance (e.g. wheel mounts, wheel diameter size changes, external gearing of motors,sensor remounting, etc)
      3. Method of fabricating each component
      4. Method of fastening each component (screws, spot welding)
      5. Method of assembly (i.e .what order to assemble the different components together.  Occasionally teams will want to combine different components in a configuration that cannot be accessed by screws or welding electrodes)
      6. Ease of assembly/dissassembly  (TINAH, battery, fasteners)
      7. Ease of redesign of major components (leave room for modification)
      8. Estimated mass of system and components.
    3. Drive System
      1. Steering method and geometry
      2. Drive mechanism and associated transmission (DC motor? Servo? Gears?)
      3. Transmission calculations – expected performance based on chosen gear ratio, motor torque, mass of robot, wheel size etc.
      4. Motors (type, number, voltage/current/power required for 1 round)
      5. Wheel size selection (estimate maximum speed, acceleration)
    4. Sensor systems
      1. TINAH Resources (Digital/Analog/Motor control specification) – include a table showing all pins and expected I/O
      2. Tape sensors
      3. IR sensors
      4. Collision detectors
      5. Edge-of-surface detectors
      6. Object detection
    5. Electrical Design
      1. List of individual PCBs used in design (each PCB is named and numbered)
      2. Primary wiring diagram (i.e. a block diagram showing each PCB to be manufactured, and the specific wiring connectors between every PCB.  Having this available allows for modular system design, and cleaner wiring on the robot).
      3. Sensor circuits
      4. IR detection circuit
      5. Motor drive circuit
      6. Power distribution
    6. Software code and algorithm
      1. Flowchart of code – if you can include detail on control algorithms at this point go ahead.
      2. Error handling algorithms:
        1. algorithm when tape is lost
        2. algorithm for deciding between tape tracks
        3. algorithm for doing 180 degree turn on tape
        4. algorithm for missed object
        5. avoiding falling off the playing surface (edge-sensors)
    7. Risk assessment
      1. Identification of the biggest risks/obstacles for your design during fabrication and operation.
      2. Contingencies – Describe any vaiable alternatives which can be pursued if a risk or obstacle occurs, or if a specific parts of the design cannot be implemented.
    8. Team Responsibilities, Major Milestones, and Timeline
      1. How tasks are divided among all 3 or 4 group members
      2. List of individual tasks required from beginning to end
        1. aim to make each on the order of 3 to 6 hrs
        2. be as specific as possible!
        3. think of what tasks need to be completed in what order
        4. think of how to test and verify major stages of your robot
      3. Group together tasks to identify 3 or 4 major milestones, and target dates.  This may include:
        1. Chassis, drive motors and wheels mounted
        2. Power circuits complete
        3. Chassis following tape
        4. Pickup mechanism complete
        5. Software can be triggered to perform based on manipulating sensor inputs.

    Key elements to the Formal Review and Design Document

    • Calculations  – What is the speed of each mechanism? What is its estimated time to travel the course?  How many objects do you expect to handle in 2 minutes?
    • Estimates -Estimate any quantities that you can’t measure easily. This can include estimating various masses, required forces.
    • Testing procedure  – Once part of your robot is constructed, how do you verify whether it works adequately or not?  Can you identify options during the design stage?
    • Come to the review prepared to answer detailed questions to defend any part of your design.  
    • The more detail you can show us, the more we can help you!

    Comments from Design Reviews from Previous Years:

    • Testing:   When you claim to be “testing” something, think specifically about how to test and obtain unambiguous, conclusive, repeatable results
      • Testing your steering mechanism
      • Testing your IR detection to maximize detection at the desired distance.
      • Testing noise in IR system when motors running (e.g. ground loops)
      • Testing identification of key playing surface elements
      • … And have alternative solutions if the system doesn’t work
    • Mech designs
      • Can you re-design your parts to be tolerant of inaccuracies in fabrication? (alignment and precision in machining are always a problem)
      • Can you design it to make it easier to get access to parts? (circuits, wiring, motors, differentials)
      • Can you minimize amount of material? (for weight, for wasted material)
    • Electronics
      • Design and build to allow for easy transfer to a new/improved robot chassis.
      • Think about inputs and outputs on each board and how connectors will attach to each setup.
      • TINAH board should only source ~500 mA total on the 5V lines  (this includes the RC servo motor)!
        • Need more 5V power?  Use an external 5V regulator (7805)
      • Most groups are missing the following:
        • 9V batteries (for +/- power)
        • Power switches
        • Wiring harnesses (wire bundles/colours)
        • Easy method of swapping out 14.4 battery replacement.

     

     

    3.  Design Document

    • To be handed in as a record of the design review process.
    • Material from the design document can be used in the final report to be handed in at the conclusion of the course.
    • Examples of design documents will be available for viewing in Hebb 42.
    • The most successful design documents are the ones which provide documentation that is actually useful during the build phase.
    • Do not spend excess amounts of time formatting text and getting documentation down – instead, focus on producing content and plans which are used to plan, fabricate and test your robot.


    4.  Final Report

    • A final report is to be handed in no later than 1 week after the completion of the course.  The Final Report is NOT marked, but represents the only document which the group is allowed to take at the completion of the course.



     














    PHYS 253 – Introduction to Instrument Design summer 2009

    www.engphys.ubc.ca/phys253

    Design Review Requirements updated 2009 May 28

    The Design Review process occurs in several stages and increasing levels of detail. Each of the stages described below is used to help give feedback to groups and highlight issues and problems that may occur during design and fabrication.

    Every group will be proposing different solutions, and different instructors and TAs will highlight different areas of concern (occasionally conflicting with one another!) Part of the experience of the course is to learn to listen to constructive comments from a variety of sources and learn to judge the relative importance of each part of feedback by the course instructors.

    #

    Type of Review

    Date

    Duration

    Reviewer

    1

    Pre-Review

    Any time during Lab 5 week A or B

    ~15 min

    Call over at least 2 instructors or TAs

    2

    Formal Review

    Signup Schedule – Week 6/7 (Lab5 Week B, or following)

    1 hr

    2 Instructors or TAs.

    3

    Design Document







    4

    Final Report

















    1. PRE-REVIEW

    Time:

    ▪ 10-15min discussion with at least 2 course instructors

    Expected:

    ▪ Verbal overview of robot function

    ▪ Sketches of primary mechanical mechanisms

    ▪ Block diagrams showing major electronic circuits,

    ▪ Primary operational/software flowchart diagram

    ▪ Major technical resources required (# and type of motors, types of sensors, linear stages/arms, items not supplied in lectures)

    Outcome:

    ▪ Identify the major problem areas to investigate in preparation for Formal Review, including:

    o Most likely areas with mechanical alignment and robustness issues

    o Motor control and sensitivity issues

    o Electronics difficulties

    o Sensor difficulty

    o Difficulty in programming and algorithm development

    2. FORMAL REVIEW

    Time:

    ▪ 10 min presentation, followed by ~45 min discussion

    Expected:

    ▪ Printed / hand drawn version of all mechanical components and method of mounting key components together.

    ▪ Electronic schematics, including block-diagram of wiring showing connections between PCBs.

    ▪ Motor and force calculations where appropriate

    A rough draft is fine as long as it includes all relevant information. The final document will be handed in later.

    You should emphasize the application of engineering theory to your design – show calculations and estimates wherever applicable. If calculations are missing you can expect to be asked to do them on the spot!

    Expected Content

    (note that all of the content does not have to be discussed in this order, but all material is expected to be known by the group and may be discussed during the Formal Design Review)

    a. Description of functions and basic strategy.

    i. Calculations of round trip time, and estimated score achieved by the Robot

    ii. Most likely sources of issues and problems in strategy.

    b. Chassis

    i. Location of critical elements on the robot (wheels, arms, sensors, etc)

    ii. Listing of each chassis component

    iii. Areas of chassis design which allow for flexibility during performance (e.g. wheel mounts, wheel diameter size changes, external gearing of motors,sensor remounting, etc)

    iv. Materials to be used for construction

    v. Method of fabricating each component

    vi. Method of attaching each component (screws, spot welding)

    vii. Method of assembly (i.e .what order to assemble the different components together. Occasionally teams will want to combine different components in a configuration that cannot be accessed by screws or welding electrodes)

    viii. Components disassembled regularly for maintenance (i.e. easy access for critical elements like motors, HandyBoards, batteries, etc)

    c. Drive System

    i. Steering method and geometry

    ii. Transmission (direct, gears, pulleys) – include calculations of expected performance based on chosen gear ratio, motor torque, mass of robot, wheel size etc.

    iii. Motors (type, number, voltage/current/power required for 1 round)

    iv. Motor and wheel mounting

    v. Wheel size selection (estimate maximum speed, acceleration)

    d. Object handling mechanism

    i. Sketch of mechanical design

    ii. Description of how mechanism will work

    iii. Drive mechanism and associated transmission (DC motor? Servo? Gears?)

    iv. Calculations of operating parameters (e.g. how much motor torque is required to raise the object?)

    e. Sensor systems

    i. IR sensors

    ii. Tape sensors

    iii. Collision detectors

    iv. Edge-of-surface detectors

    v. Object detection

    f. Circuits – general schematics are expected for the following

    i. Motor drive circuit

    ii. IR detection circuit

    iii. Steering control circuit (if applicable)

    iv. Sensor circuits

    v. Any other circuits

    vi. Wiring harness (i.e. a block diagram showing each PCB to be manufactured, and the wiring which will connect every PCB in the circuit).

    g. Software code and algorithm

    i. Flowchart of code – if you can include detail on control algorithms at this point go ahead.

    ii. Error handling algorithms:

    1. algorithm when tape is lost

    2. algorithm for deciding between tape tracks

    3. algorithm for doing 180deg turn on tape

    4. algorithm for missed object

    5. avoiding falling off the playing surface (edge-sensors)

    iii. Digital/Analog/Motor control specification – include a table showing all expected I/O from the Handyboard and which sensors will be used

    h. Team Responsibilities, Major Milestones, and Timeline

    i. How are tasks divided among all 3 or 4 group members

    ii. 4 or 5 major milestones and target dates. E.g.

    ▪ Chassis, drive motors and wheels mounted

    ▪ Power circuits complete

    ▪ Chassis following tape

    ▪ Pickup mechanism complete

    ▪ Software can enter into various states based on manually generating sensor inputs.

    3. DESIGN DOCUMENT

    To be handed in as a record of the design review process. Material from the design document can be used in the final report to be handed in at the conclusion of the course.

    Examples of design documents will be available for viewing in Hebb 42.

    ** The most successful design documents are the ones which provide documentation that is usable ** Do not spend excess amounts of time formatting text and getting documentation down – instead, focus on producing content and plans which are used to plan, fabricate and test your robot.

    4. FINAL REPORT

    A final report is to be handed in no later than 1 week after the completion of the course. The Final Report is NOT marked, but represents the only document which the group is allowed to take at the completion of the course.