Human Following Robot

🤖 Project Overview

Yeh robot ultrasonic sensor aur servo motor use karke insaan ya kisi bhi object ko automatically follow karta hai. Servo scan karta hai left-center-right aur distance ke hisaab se robot aage, left ya right move karta hai.

✅ Features

Auto Follow Object ko track karta hai

360° Scan Servo se left/right dekho

Safe Stop Bahut paas aane par rukta hai

Distance Limit Range ke bahar stop

4WD Stable movement

📏 Working Range

TOO CLOSE

0–20 cm → STOP 🛑

FOLLOW ZONE

20–40 cm → FOLLOW ✅

TOO FAR

40+ cm → STOP 🛑

📊 System Status

Ultrasonic Sensor — Working Servo Motor — Working 4x DC Motors — Working Motor Driver Shield — Working Arduino Uno — Working ESP32-CAM — Pending

🎛️

ARDUINO UNO

Main brain — sab sensors aur motors ko control karta hai. ATmega328 chip based microcontroller.

ATmega328 | 14 Digital Pins | 6 Analog

📡

HC-SR04

Ultrasonic distance sensor — sound waves se distance measure karta hai. Servo pe mounted hai scanning ke liye.

Range: 2cm–200cm | 40kHz

🔄

SG90 SERVO

HC-SR04 ko left-right-center ghoomata hai taaki robot side mein bhi detect kar sake.

180° Rotation | 4.8V–6V

⚙️

MOTOR SHIELD

AFMotor Shield — Arduino se 4 DC motors control karta hai. Speed aur direction dono control hote hain.

4x DC Motor | L293D chip

🚗

DC GEAR MOTORS

4 wheel drive ke liye 4 motors. Gear mechanism se speed control hoti hai. Yellow chassis pe mounted.

4x Motors | M1 M2 M3 M4

🔋

LI-ION BATTERY

3x 18650 Li-ion cells — 11.1V total power supply. EXT-PWR terminal se connect hoti hai shield mein.

3x 3.7V = 11.1V Total

🔌 Pin Connections

Component	Pin	Arduino/Shield	Voltage
HC-SR04 VCC	VCC	+5V	5V
HC-SR04 GND	GND	GND	0V
HC-SR04 TRIG	TRIG	A1	Signal
HC-SR04 ECHO	ECHO	A0	Signal
Servo Orange	Signal	Pin 10	PWM
Servo Red	VCC	+5V	5V
Servo Brown	GND	GND	0V
Battery +	+	EXT-PWR +	11.1V
Battery -	-	EXT-PWR -	GND

🔄 Scan Logic

// Servo scan sequence:
CENTER (90°) → distance check
LEFT   (150°) → distance check  
RIGHT  (20°)  → distance check
CENTER (90°) → wapas reset

// Decision:
Center < 40cm → FORWARD
Left < 40cm   → LEFT TURN
Right < 40cm  → RIGHT TURN
Kuch nahi     → STOP
        

⚡ Response Flow

📡 Scan → Servo ghoomta hai 3 directions

📏 Measure → Distance milti hai cm mein

🧠 Decide → Arduino logic check karta hai

⚙️ Execute → Motors ko command deta hai

🔁 Repeat → Har 40ms mein cycle hoti hai

🚀 Robot Start Karne Ka Tarika

BATTERY CHECK KARO

3x Li-ion batteries fully charged honi chahiye. EXT-PWR terminal mein properly connected ho. Red wire + mein, black wire - mein.

POWER ON KARO

Switch on karo — Arduino ka green LED jalega. Servo startup sweep karega (90° → 180° → 0° → 90°). Yeh normal hai!

ROBOT KE SAAMNE KHADE HO

Robot se 25-35cm door khade ho. Sensor ki direct line of sight mein raho. Robot turant scan shuru karega.

FOLLOW KARO

Dhire dhire peeche hato — robot follow karega. 20-40cm ki range maintain karo. Side mein jao — servo scan karke left/right turn lega.

ROBOT BAND KARO

Sensor ke saamne se hat jao — robot ruk jayega. Phir switch off karo. Batteries nikalo agar lambe time ke liye band kar rahe ho.

✅ Robot Kya Karega

✅ 20-40cm range mein aage chalega

✅ 20cm se paas aane par rukega

✅ Left side mein detect hone par left mudega

✅ Right side mein detect hone par right mudega

✅ 40cm se door hone par rukega

✅ Servo scan se 3 directions dekh sakta hai

⚠️ Dhyan Rakho

⚠️ Smooth floor pe better kaam karta hai

⚠️ Sensor ke saamne koi wall mat rakho

⚠️ Ek baar mein ek hi object track karo

⚠️ Battery low hone par speed kam hogi

⚠️ Wires tangle na hon — check karo

⚠️ Direct sunlight mein sensor affect ho sakta hai

⚙️ Tune Karne Ke Liye Sirf Yeh 4 Numbers

// Code ke top mein yeh define hain:

#define TOO_CLOSE    20   // cm — paas ki limit (badhao = zyada door rukta hai)
#define FOLLOW_END   40   // cm — door ki limit (badhao = door se bhi follow karega)
#define FWD_SPEED    150  // 0-255 — forward speed (badhao = tez chalega)
#define TURN_SPEED   160  // 0-255 — turn speed (badhao = sharp turn lega)
      

📋 Problem → Solution

Problem	Fix
Bahut paas aa jata hai	TOO_CLOSE badhao (20→30)
Door se nahi follow karta	FOLLOW_END badhao (40→60)
Bahut tez chalta hai	FWD_SPEED ghataao (150→100)
Turn sharp nahi hai	TURN_SPEED badhao (160→200)
Galat direction mein mud raha	Servo angles swap karo
Ruk nahi raha paas mein	TOO_CLOSE badhao

🔭 Servo Angles

// Scan angles change karo:

CENTER → 90   // seedha saamne
LEFT   → 150  // left scan
RIGHT  → 20   // right scan

// Agar left/right ulta ho:
LEFT  → 30   // swap karo
RIGHT → 150  // swap karo
        

🔮 Future Upgrades

📷

ESP32-CAM

Video feed + WiFi mobile control

🌡️

PIR SENSOR

Human body heat detection

📱

BLUETOOTH

Mobile se manual control

BATTERY CHECK KARO

POWER ON KARO

ROBOT KE SAAMNE KHADE HO

FOLLOW KARO

ROBOT BAND KARO