05 CONCEPT EVALUATION AND PRODUCT ARCHITECTURE - Q-div-Engg-Exploration-2026-27-Odd/Repo-5 GitHub Wiki

PUGH CHART

Design Objectives

Design Objectives	Weight	Design 1	Design 2	Design 3	Design 4
Ease of Use	5	++	-	Datum	+
Portability	6	0	0	Datum	0
Use of Standard Components	4	0	+	Datum	+
Cost	3	+	-	Datum	+
Drawing Accuracy	9	0	++	Datum	+
Score (+)		13	22	0	21
Score (-)		0	-8	0	0
Total		13	14	0	21

5.1 JUSTIFICATION FOR SCORE GIVEN

Design No.	Objective	Score Allocated	Justification for the Score
1	Ease of Use	+10	More user-friendly and intuitive.
1	Portability	0	Lighter and easier to transport.
1	Use of Standard Components	0	Similar parts as datum.
1	Cost	+3	Almost the same as that of the datum.
1	Drawing Accuracy	0	Same as that of the datum.
2	Ease of Use	-5	More complex and harder to operate.
2	Portability	0	Same as the datum.
2	Use of Standard Components	+4	Uses standard components for easy repair.
2	Cost	-3	Higher cost due to added components.
2	Drawing Accuracy	+18	More precise and accurate drawings can be obtained.
3	Ease of Use	0	Datum.
3	Portability	0	Datum.
3	Use of Standard Components	0	Datum.
3	Cost	0	Datum.
3	Drawing Accuracy	0	Datum.
4	Ease of Use	+5	Easier to use than the datum.
4	Portability	0	Similar to the datum in portability.
4	Use of Standard Components	+4	Components are better than those of the datum.
4	Cost	+3	Cost-efficient and easy to use.
4	Drawing Accuracy	+9	Produces manageable and accurate drawings.

5.2 SELECTED DESIGN

Sl. No.	Subsystem	Main Components
1	Move Around (Locomotion)	Wheel/Motor Assembly, Chassis/Frame, Drive Control, Balance/Stability Mechanism
2	Hold and Move Pen	Pen Holder/Clamp, Servo Motor, Linkage Arm, Pen Tip/Marker
3	Control System	Microcontroller (Arduino/ESP32), Motor Driver, Servo Driver, Power Supply (Battery)
4	Sense Position & Feedback	Position Sensor (Encoder/IR), Obstacle Sensor (Ultrasonic/IR), Limit Switch, Feedback to Microcontroller
5	Drawing Surface & Output	Paper/Board, Marker/Pen, Pen Pressure Mechanism, Finished Scribble Output

Type	Subsystem 1: Move Around (Locomotion)	Subsystem 2: Hold and Move Pen
Spatial	Wheels, motors and chassis support the pen mechanism	Pen holder and linkage mechanism mounted on the moving structure
Data	Sends movement and direction information	Receives movement commands for pen positioning
Material	Wheels, motors, chassis and mechanical connections	Pen holder, servo motor, linkage arm and pen

The locomotion subsystem moves the Scribble Bot across the drawing surface.
The movement of the bot determines the path followed by the pen.
The pen mechanism moves along with the bot and maintains the required drawing position.

Type	Subsystem 2: Hold and Move Pen	Subsystem 3: Control System
Spatial	Pen holder, servo motor and linkage mechanism mounted on the chassis	Microcontroller, motor drivers and power supply connected to the system
Data	Receives pen movement commands	Sends commands for pen movement and position
Material	Pen holder, servo motor, linkage arm and pen	Microcontroller, motor driver, servo driver and battery

Type	Subsystem 3: Control System	Subsystem 4: Sense Position & Feedback
Spatial	Microcontroller and drivers connected to the sensing system	Position, obstacle and limit sensors mounted on the robot
Data	Receives sensor feedback and processes it for control	Sends position, obstacle and limit information
Material	Microcontroller, motor drivers, servo driver and wiring	Position sensor, obstacle sensor, limit switch and signal connections

The sensing subsystem detects the position and operating conditions of the Scribble Bot.
Sensors send feedback information to the microcontroller.
The control system uses this feedback to adjust movement and maintain safe operation.

Type	Subsystem 4: Sense Position & Feedback	Subsystem 5: Drawing Surface & Output
Spatial	Sensors monitor the bot and drawing area	Paper/board provides the drawing surface
Data	Provides position and movement feedback	Receives the controlled pen movement to create the drawing
Material	Sensors, limit switches and connections	Paper/board, marker/pen and pen pressure mechanism

The sensing subsystem helps determine the position and movement of the Scribble Bot.
Position feedback helps the robot maintain the required drawing path.
The drawing subsystem converts the controlled pen movement into the final scribbled output.

Type	Subsystem 1: Move Around (Locomotion)	Subsystem 3: Control System
Spatial	Motors and wheels are mechanically connected to the chassis	Microcontroller and motor driver control the motors
Data	Receives movement and speed commands	Sends movement and speed commands
Material	Wheels, motors, chassis and drive mechanism	Microcontroller, motor driver, servo driver and wiring

The control system generates the required movement commands.
The motor driver receives signals from the microcontroller and controls the motors.
The locomotion system converts these commands into physical movement of the Scribble Bot.

Type	Subsystem 2: Hold and Move Pen	Subsystem 5: Drawing Surface & Output
Spatial	Pen mechanism is positioned above the drawing surface	Paper/board provides the surface for drawing
Data	Controls pen position and movement	Receives pen movement to produce the drawing
Material	Pen holder, servo motor, linkage arm and pen	Paper/board, marker/pen and pressure mechanism