my robot is working fine with just one single sonar and using that same old ping library
all i did was calibrating the time of servo movement with the time taken by sonar to take a reading
digitalWrite(trigPin, LOW); // Set the trigger pin to low for 2uS
delayMicroseconds(2);
digitalWrite(trigPin, HIGH); // Send a 10uS high to trigger ranging
delayMicroseconds(10);
digitalWrite(trigPin, LOW); // Send pin low again
int distance = pulseIn(echoPin, HIGH); // Read in times pulse
distance= distance/58; // Calculate distance from time of pulse
delay(10); // Wait 50mS before next ranging
Here's the video of robot
