How to code arduino car

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9

This is my coding currently. I have changed the stop time to 30 sec and simplified step 4~5. But it does not function as well as I thought. It stops and goes smooth but it does not move away when an object is blocking. What statement should I use?

#include <SoftwareSerial.h>
 

#define LEFT_A1 4
#define LEFT_B1 5
#define RIGHT_A2 6 
#define RIGHT_B2 7 
 

#define IR_TRIG 9 
#define IR_ECHO 8 
 
void setup() {
  Serial.begin(9600);  
 

  pinMode(LEFT_A1, OUTPUT);
  pinMode(RIGHT_A2, OUTPUT);
  pinMode(LEFT_B1, OUTPUT);
  pinMode(RIGHT_B2, OUTPUT);  
 

  pinMode(IR_TRIG, OUTPUT);
  pinMode(IR_ECHO, INPUT);
}
 
void loop() {
  float duration, distance;
  digitalWrite(IR_TRIG, HIGH);
  delay(10);
  digitalWrite(IR_TRIG, LOW);
 

  duration = pulseIn(IR_ECHO, HIGH);

  distance = ((float)(340 * duration) / 10000) / 2;
  Serial.print("\nDistance : ");
  Serial.println(distance);
  int sum = 0;
  

 
   
   if(distance < 20) {      
     Serial.println("stop");
     stop(); 
     sum++ ;
   
     while (sum > 10) {
     Serial.println("backward");
     backward ();
     Serial.println("left");
     left ();
     Serial.println("forwardi");
     forwardi ();
     Serial.println("right");
     right ();
     Serial.println("forwardi");
     forwardi ();
     Serial.println("forwardi");
     forwardi ();
     Serial.println("right");
     right ();
     Serial.println("forwardi");
     forwardi ();
     Serial.println("left");
     left ();
     Serial.println("forward");
     forward();
     }
   }else {        
     Serial.println("forward");
     forward();
   }
}
 
void forward(){
  digitalWrite(LEFT_A1, HIGH);
  digitalWrite(LEFT_B1, LOW);
  digitalWrite(RIGHT_A2, HIGH);
  digitalWrite(RIGHT_B2, LOW);
}
void forwardi (){
  digitalWrite(LEFT_A1, HIGH);
  digitalWrite(LEFT_B1, LOW);
  digitalWrite(RIGHT_A2, HIGH);
  digitalWrite(RIGHT_B2, LOW);
  delay (4000);
}
void backward(){
  digitalWrite(LEFT_A1, LOW);
  digitalWrite(LEFT_B1, HIGH);
  digitalWrite(RIGHT_A2, LOW);
  digitalWrite(RIGHT_B2, HIGH);
  delay(1000);
}
void left(){
  digitalWrite(LEFT_A1, LOW);
  digitalWrite(LEFT_B1, HIGH);
  digitalWrite(RIGHT_A2, HIGH);
  digitalWrite(RIGHT_B2, LOW);
  delay(1000);
}
void right(){
  digitalWrite(LEFT_A1, HIGH);
  digitalWrite(LEFT_B1, LOW);
  digitalWrite(RIGHT_A2, LOW);
  digitalWrite(RIGHT_B2, HIGH);
  delay(1000);
}
void stop(){
  digitalWrite(LEFT_A1, LOW);
  digitalWrite(LEFT_B1, LOW);
  digitalWrite(RIGHT_A2, LOW);
  digitalWrite(RIGHT_B2, LOW);
  delay(3000);
}