Arduino Human Following Robot Project

 

The Human Following Robot uses ultrasonic sensors to detect a person and automatically follows them while maintaining a safe distance. The robot moves forward, left, right, or stops based on human position.

🔧 Components Required

• Arduino UNO

• Ultrasonic Sensor HC-SR04 (1 or 2 sensors)

• Motor Driver L298N

• DC Motors × 2

• Robot Chassis + Wheels

• 12V Battery / Power Bank

• Jumper Wires

• Breadboard

(Optional: IR sensors for better accuracy)

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⚙️ Working Principle

1. Ultrasonic sensor emits ultrasonic waves.

2. Waves reflect from the human body.

3. Arduino calculates distance.

4. Based on distance:

   • Too far → Move Forward

   • Too close → Stop

   • Left detected → Turn Left

   • Right detected → Turn Right

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📐 Distance Formula

Distance (cm) = (Time × 0.034) / 2

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🔌 Circuit Connections

HC-SR04 → Arduino

HC-SR04	Arduino
VCC	5V
Trig	D9
Echo	D10
GND	GND

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L298N Motor Driver → Arduino

L298N Pin	Arduino
IN1	D2
IN2	D3
IN3	D4
IN4	D5
ENA	5V
ENB	5V
GND	GND

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💻 Arduino Code

#define trigPin 9
#define echoPin 10

#define IN1 2
#define IN2 3
#define IN3 4
#define IN4 5

long duration;
int distance;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);

  Serial.begin(9600);
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;

  Serial.println(distance);

  if (distance > 20 && distance < 60) {
    moveForward();
  } 
  else if (distance <= 20) {
    stopRobot();
  } 
  else {
    stopRobot();
  }
}

void moveForward() {
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, HIGH);
  digitalWrite(IN4, LOW);
}

void stopRobot() {
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, LOW);
}

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📊 Output Behavior

Distance	Robot Action
> 60 cm	Stop
20–60 cm	Follow Human
< 20 cm	Stop

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🚀 Applications

• Assistant robots

• Service robots

• Surveillance robots

• Smart shopping carts

• Robotics learning projects