Page 108 - Toucpad robotics C11

21 st #Coding & Computational Thinking
project 1 Century #Experiential learning
Skills
The Autonomous Delivery Robot
Objective: Design and build a mobile robot that can navigate a simple indoor environment (e.g., a classroom or
corridor), avoid obstacles, and autonomously deliver a small item from a starting point to a pre-defined destination.
Steps of the Solution:
1. Project Planning & Design (Project Management):
∑ Define the Scope: Specify the robot's size, the maximum payload, its speed, and the complexity of the
environment (e.g., a flat surface with static obstacles).
∑ Component Selection (Power, Brain, Senses, Muscles):
Brain: Choose a microcontroller (like an Arduino Mega) or a Single Board Computer (like a Raspberry
§
Pi 4) as the central processing unit.
§ Senses: Select ultrasonic sensors for obstacle avoidance and wheel encoders for tracking distance
travelled.
§ Muscles: Choose two Direct Current motors with gearboxes for the drive wheels and a servo motor
for a simple gripper or a lifting mechanism.
§ Power: Select a suitable Lithium-ion battery for its high energy density to power the robot.
∑ Frame & Wheels: Design the chassis (frame) using lightweight materials like acrylic or MDF. Choose
standard wheels for the drive and a castor wheel for balance.
2. Hardware Assembly & Wiring:
∑ Build the Chassis: Cut the chosen material and assemble the chassis.
∑ Mount Components: Securely mount the motors, sensors, battery, and microcontroller to the chassis.
∑ Wiring: Connect all the components to the microcontroller. This includes wiring the motors through a
motor driver (a separate circuit that amplifies the microcontroller's low-power signals to drive the motors),
connecting the ultrasonic sensors, and wiring the servo motor.
3. Programming & Control (Fundamentals, Logic, Systems):
∑ Basic Movement: Write basic code to control the Direct Current motors for forward, backward, left, and
right movements.
∑ Sensor Integration: Write code to read data from the ultrasonic sensors. Use Boolean operators to create
simple decision logic. For example, IF (front_sensor_distance < THRESHOLD) THEN (stop_and_turn).
∑ Navigation Algorithm: Implement a simple algorithm for autonomous navigation.
§ Step 1: Move forward.
§ Step 2: Continuously check for obstacles using the front ultrasonic sensor.
§ Step 3: If an obstacle is detected, stop, check the left and right sensors to find a clear path, and turn
in that direction.
§ Step 4: Repeat the process until the robot reaches its destination.
∑ Object Delivery: Program the servo motor to activate at the destination point to either lift or drop the item.
4. Debugging & Testing (Ensuring Performance):
∑ Unit Testing: Test each component individually. Ensure the ultrasonic sensors provide accurate readings
and that the motors spin correctly.
∑ Integration Testing: Test the entire system. Place the robot in a test environment with a simple obstacle
course and run the code to ensure the navigation algorithm works as expected.
∑ Performance Testing: Measure the robot's accuracy in reaching the destination and its efficiency in
avoiding obstacles.

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Touchpad Robotics - XI