Improvement in autonomous robot

I added a sensor to the autonomous robot which avoids obstacles.

Post about the autonomous robot that avoids obstaclesClick here

With an additional ultrasound sensor, the robot not only avoids obstacles but also avoids falls, detecting edges.

The code is below.

#include <NewPing.h>
#include <Servo.h>
#define trigPin 9
#define echoPin 10
#define trigPin2 12
#define echoPin2 11

Servo servo;
int posservo;
 
int IN1=4;
int IN2=5;
int IN3=7;
int IN4=2;
int ENA=3;
int ENB=6;

#define max_distance 200
boolean goesForward = false;
int distance;
 
NewPing sensor(trigPin,echoPin,max_distance);
  
void setup() {
  servo.attach(8);
  pinMode(IN1,OUTPUT);
  pinMode(IN2,OUTPUT);
  pinMode(IN3,OUTPUT);
  pinMode(IN4,OUTPUT);
  pinMode(ENA,OUTPUT);
  pinMode(ENB,OUTPUT);
  pinMode(echoPin,INPUT);
  pinMode(trigPin,OUTPUT);
  pinMode(echoPin2,INPUT);
  pinMode(trigPin2,OUTPUT);
  Serial.begin(9600);
  servo.write(90);
  delay(150);
}
void loop(){
 analogWrite(ENA,210);
 analogWrite(ENB,190);
 int distanceR=0;
 int distanceL=0;
 distance = readPing();
 Serial.println(distance);
 Serial.print("\n");
 if(distance <= 20){//Verify if there are obstacles in front.
    moveStop();
    delay(300);
    moveBackward();
    delay(400);
    moveStop();
    delay(300);
    distanceR = lookRight();
    delay(300);
    distanceL = lookLeft();
    delay(300);
    if (distanceR >= distanceL){
      turnRight();
      moveStop();
    }
    else{
      turnLeft();
      moveStop();
    }  
 }else{
  moveForward();
 }
  digitalWrite(trigPin2,LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin2,HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin2,LOW);
  long duration=pulseIn(echoPin2,HIGH);
  long distance2=duration/29/2;
  Serial.println(distance2);
  if(distance2>10){
    moveBackward();
    delay(1000);
    turnRight();
    delay(1000);
  }
}
int lookRight(){  
  servo.write(0);
  delay(150);
  int distance = readPing();
  delay(100);
  servo.write(90);
  return distance;
}
int lookLeft(){
  servo.write(180);
  delay(150);
  int distance = readPing();
  delay(100);
  servo.write(90);
  return distance;
  delay(100);
}
int readPing(){
  delay(70);
  int cm = sensor.ping_cm();
  if (cm==0){
    cm=250;
  }
  return cm;
}
void moveStop(){
   
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, LOW);
}
void turnRight(){
   digitalWrite(IN1,HIGH);
   digitalWrite(IN2,LOW);
   digitalWrite(IN3,HIGH);
   digitalWrite(IN4,LOW);
   delay(600);  //Value must change, depending on battery charge.
   digitalWrite(IN1,LOW);
   digitalWrite(IN2,HIGH);
   digitalWrite(IN3,HIGH);
   digitalWrite(IN4,LOW);
}
void turnLeft(){
   digitalWrite(IN1,LOW);
   digitalWrite(IN2,HIGH);
   digitalWrite(IN3,LOW);
   digitalWrite(IN4,HIGH);
   delay(600);  //Value must change, depending on battery charge.
   digitalWrite(IN1,LOW);
   digitalWrite(IN2,HIGH);
   digitalWrite(IN3,HIGH);
   digitalWrite(IN4,LOW);
}
void moveForward(){
  if(!goesForward){
    goesForward=true;
    digitalWrite(IN1,LOW);
    digitalWrite(IN2,HIGH);
    digitalWrite(IN3,HIGH);
    digitalWrite(IN4,LOW);
    }
}
void moveBackward(){
  goesForward=false;
  digitalWrite(IN1,HIGH);
  digitalWrite(IN2,LOW);
  digitalWrite(IN3,LOW);
  digitalWrite(IN4,HIGH);
}