5.CONCEPT EVALUATION AND PRODUCT ARCHITECTURE - W-Div-Engg-Exploration-Odd-2026-27/Repo-11 GitHub Wiki

PUGH CHART

Task 1: Assign Weights to the Objectives

Objectives Weights
Safety 9
Ease of use 7
Portability 5
Use of standard 6
Cost 6

Task 2: Pugh Chart for Alternative Designs

Reference datum: Gimbal

Design Objectives Weights Polar Tracker Gimbal (Datum) Bladeless Monolith Tower Unidirect
Safety 9 - datum + + -
Ease of use 7 + datum + - +
Portability 5 + datum 0 0 0
Use of standard 6 + datum + + -
Cost 6 ++ datum - - +
Score (+) 30 0 23 15 13
Score (-) -9 0 -6 -13 -15
Total 21 0 17 2 -2

5.1 JUSTIFICATIONS FOR SCORE GIVEN

Design No. Objective Score Allocated Justification for the Score
1 Safety -9 Blades are unsafe
Ease of use 7 Easy access
Portability 5 Lightweight material
Use of standard 6 Outstanding adherence to standard components
Cost 12 Affordable price range
2 Safety 9 Enhanced structural safety characteristic compared to Gimbal
Ease of use 7 Simpler and more user-friendly interface
Portability 0 Offers a slight layout or design advantage for portability
Use of standard 6 Uses standard components
Cost -6 Cost is balanced
3 Safety 9 Safety profile is standard and directly on par with baseline gimbal
Ease of use -7 Operating complexity is virtually identical to baseline
Portability 0 Significantly bulkier or harder to transport
Use of standard 6 Utilizes fewer standard parts
Cost -6 Considerably more expensive
4 Safety -9 Safe design with structural features and stability
Ease of use 7 Offers standard operational complexity
Portability 0 Features a streamlined directionally focused layout
Use of standard -6 Adheres well to industry guidelines
Cost 6 Standard manufacturing and material layout

5.2 SELECTED DESIGN

Selected Concept: Design 1 (Polar Tracker)

Based on the quantitative evaluation in the Pugh Matrix (Task 2), Design 1 (Polar Tracker) achieved the highest overall score of +21, decisively outperforming the Gimbal datum (0), Bladeless (17), Monolith Tower (2), and Unidirectional (-2) configurations.

Key Justifications for Selection:

  1. Superior Cost Efficiency (Score: +12):
    • Utilizes standard commercial off-the-shelf (COTS) components, high-torque servos, and an axial bladed fan rather than complex custom impellers, making it the most economical design to prototype well within the β‚Ή5,000–₹10,000 budget ceiling.
  2. High Ease of Use & Accessibility (Score: +7):
    • Intuitive direct access for maintenance and repair; open structural layout allows straightforward mounting, testing, and servicing of tracking sensors and actuators.
  3. Adherence to Industry Standards (Score: +6):
    • Incorporates standardized modular parts (standard MG996R servo, 120mm 5-blade rotor, and standard framing) that minimize custom tooling requirements and assembly complexity.
  4. Lightweight Portability (Score: +5):
    • Lower overall bulk and reduced structural mass allow for easy relocation across desktop workspaces without excessive weight penalties.
  5. Mitigation of the Safety Penalty (-9):
    • While the open rotor configuration was initially scored -9 for safety compared to the datum, this penalty is fully addressed in the physical prototype by enclosing the rotor in an OSHA/IEC compliant, high-density slotted protective radial grille ($\le 7\text{ mm}$ spacing), effectively eliminating finger pinch and entanglement hazards without forfeiting cost and airflow advantages.

5.3 PRODUCT ARCHITECTURE

Activity 2.2 : Subsystem List

SL. No. Subsystem Description
1 Sense and track Vision tracking (ESP32-S3-CAM) and distance ranging (ToF laser)
2 Control motion Pan/yaw rotational turntable and tilt pitch elevation actuators
3 Deliver comfort Airflow generation (centrifugal blower) and Coandă multiplier loop
4 Power and logic 12V-to-5V/3.3V DC power regulation and embedded control firmware

5.4 FUNCTION CLUSTERING

graph TD
    Root["Smart Person-Tracking Desk Fan"]

    Root --> S1["1. Sense & Track"]
    Root --> S2["2. Control Motion"]
    Root --> S3["3. Deliver Comfort"]
    Root --> S4["4. Power & Logic"]

    S1 --> A1["Detect User (Camera)"]
    S1 --> A2["Measure Distance (ToF)"]
    S1 --> A3["Recognize Gestures (TinyML)"]

    S2 --> B1["Pan Rotation (Yaw - 360Β°)"]
    S2 --> B2["Tilt Elevation (Pitch)"]
    S2 --> B3["Maintain Angle (Encoders)"]

    S3 --> C1["Generate Airflow (Blower)"]
    S3 --> C2["Multiply Air (Airfoil Loop)"]
    S3 --> C3["Atomize Water (Piezo Mist)"]
    S3 --> C4["Dampen Noise (Helmholtz)"]

    S4 --> D1["Convert Voltage (12V to 5V/3.3V)"]
    S4 --> D2["Execute Code (ESP32-S3)"]
    S4 --> D3["Manage Standby (Sleep Mode)"]

5. CONCEPT EVALUATION AND PRODUCT ARCHITECTURE

PUGH CHART

Task 1: Assign Weights to the Objectives

Objectives Weights
Safety 9
Ease of use 7
Portability 5
Use of standard 6
Cost 6

Task 2: Pugh Chart for Alternative Designs

Reference datum: Gimbal

Design Objectives Weights Polar Tracker Gimbal (Datum) Bladeless Monolith Tower Unidirect
Safety 9 - datum + + -
Ease of use 7 + datum + - +
Portability 5 + datum 0 0 0
Use of standard 6 + datum + + -
Cost 6 ++ datum - - +
Score (+) 30 0 23 15 13
Score (-) -9 0 -6 -13 -15
Total 21 0 17 2 -2

5.1 JUSTIFICATIONS FOR SCORE GIVEN

Design No. Objective Score Allocated Justification for the Score
1 Safety -9 Blades are unsafe
Ease of use 7 Easy access
Portability 5 Lightweight material
Use of standard 6 Outstanding adherence to standard components
Cost 12 Affordable price range
2 Safety 9 Enhanced structural safety characteristic compared to Gimble
Ease of use 7 Simpler and more user friendly interface
Portability 0 Offers a slight layout or design advantage for portability
Use of standard 6 Uses standard components
Cost -6 Cost is balanced
3 Safety 9 Safety profile is standard and directly on par with baseline gimble
Ease of use -7 Operating complexity is virtually identical to baseline
Portability 0 Significantly bulkier or harder to transport
Use of standard 6 Utilizes fewer standard parts
Cost -6 Considerably more expensive
4 Safety -9 Safe design with structural features and stability
Ease of use 7 Offers standard operational complexity
Portability 0 Features a streamlined directionally focused layout
Use of standard -6 Adheres well to industry guidelines
Cost 6 Standard manufacturing and material layout

5.2 SELECTED DESIGN

Selected Concept: Design 1 (Polar Tracker)

Based on the quantitative evaluation in the Pugh Decision Matrix, Design 1 (Polar Tracker) achieved the highest overall score of +21, outperforming the Gimbal datum (0), Bladeless (17), Monolith Tower (2), and Unidirectional (-2).

Key Justifications for Selection:

  • Optimal BOM Budget (+12): Utilizes standard commercial off-the-shelf (COTS) parts and standard DC axial drives, keeping prototype cost well under the β‚Ή10,000 INR ceiling.
  • Ease of Use & Assembly (+7): Straightforward access to actuators and electrical harness simplifies bench testing, calibration, and maintenance.
  • Component Standardization (+6): Relies on widely available MG996R servos, 120mm 5-blade rotors, and ESP32-S3 modules without requiring expensive custom mold tooling.
  • Portability & Weight (+5): Avoids heavy internal acoustic plenum chambers and bulky blower cavities.
  • Safety Penalty Mitigation (-9): The unshielded blade risk is resolved in the CAD prototype by enclosing the rotor inside an IEC/OSHA-compliant, high-density radial grille with $\le 7\text{ mm}$ spacing to prevent finger contact.

5.3 PRODUCT ARCHITECTURE

Activity 2.2 : Subsystem List

SL. No. Subsystem
1 Sense and track
2 Control motion
3 Deliver comfort
4 Power and logic

5.4 FUNCTION CLUSTERING

graph TD
    Root["Smart Person-Tracking Desk Fan"]

    Root --> S1["1. Sense & Track"]
    Root --> S2["2. Control Motion"]
    Root --> S3["3. Deliver Comfort"]
    Root --> S4["4. Power & Logic"]

    S1 --> A1["Detect User (Camera)"]
    S1 --> A2["Measure Distance (ToF)"]
    S1 --> A3["Recognize Gestures (TinyML)"]

    S2 --> B1["Pan Rotation (Yaw - 360Β°)"]
    S2 --> B2["Tilt Elevation (Pitch)"]
    S2 --> B3["Maintain Angle (Encoders)"]

    S3 --> C1["Generate Airflow (Blower)"]
    S3 --> C2["Multiply Air (Airfoil Loop)"]
    S3 --> C3["Atomize Water (Piezo Mist)"]
    S3 --> C4["Dampen Noise (Helmholtz)"]

    S4 --> D1["Convert Voltage (12V to 5V/3.3V)"]
    S4 --> D2["Execute Code (ESP32-S3)"]
    S4 --> D3["Manage Standby (Sleep Mode)"]

5.5 INTERACTION BETWEEN SUBSYSTEMS

Activity 3 : Interaction Details

Primary Subsystem Target Subsystem Spatial Data Material Interaction Details
Subsystem 1(Sense and track) Subsystem 2 β˜‘ β˜‘ ☐ Subsystem 2: Tracking subsystem determines the person's position and direction. Data: send the detected position/angle information.
Subsystem 3 β˜‘ β˜‘ ☐ Subsystem 3: Detects where the person is located so the fan can face them. Data: provides person location information for directing airflow.
Subsystem 2(Control motion) Subsystem 1 ☐ β˜‘ ☐ Subsystem 1: Data: motion control system receives the person's position/angle data from the tracking system and uses it to decide the required movement.
Subsystem 3 β˜‘ ☐ β˜‘ Subsystem 3: Spatial: changes the fan's orientation toward the person. Material: mechanical movement is transferred through the fan's rotating mechanism.
Subsystem 3(Deliver comfort) Subsystem 1 β˜‘ ☐ β˜‘ Subsystem 1: Spatial: fan direction is adjusted according to the person's detected position. Material: airflow is delivered toward the detected person.
Subsystem 2 ☐ ☐ β˜‘ Subsystem 2: Material: motor mechanism physically moves the fan assembly.
Subsystem 4(Power and logic) Subsystem 1 β˜‘ ☐ β˜‘ Subsystem 1: Spatial: components are physically positioned within the fan system. Material: power is physically supplied through electrical components.
Subsystem 2 ☐ β˜‘ β˜‘ Subsystem 2: Data: control signals are exchanged between the controller and motor control system. Material: electrical power is supplied to the motor and control components.

selected design