A direction finding vehicle

Hey all,

I'm working on a direction finding circuit that is gonna be controlling a small vehicle with the help of a microcontroller. I am planning to use 4 ultrasonic receivers and 1 ultrasonic transmitter. The receivers would be placed on top of the vehicle (each receiver would face a different direction like the front, rear, left and right sides of the vehicle) and the transmitter at about 5m away facing the car.
The objective would be to turn the vehicle to face the direction of transmission. This, i'm planning to achieve using the voltage given out by the 4 ultrasonic receivers. If the receiver in the front of the vehicle gives a higher voltage than the other 3, the vehicle would move forward. If the one on the right gives a higher voltage, the vehicle would turn in a clockwise manner to face the transmitter. Is this possible?? Or would it be better to use a radio direction finding (which i'm not so sure about )??

If your robot is big enough, a better solution could be to place two sensors facing forward and with good space between them. You could then calculate the time difference between received pulses.
Something like this (read the "beacon detection" parts):
https://www.electro-tech-online.com/custompdfs/2012/05/powerrobotics_proposal.pdf
https://www.electro-tech-online.com/custompdfs/2012/05/Power_Robotics_Final_Report.pdf

Hey Mr.T,
The problem is, my robot's chassis is pretty small.. Dimensions : 17cm by 10cm.. My vehicle is supposed to turn in the direction facing the ultrasonic transmitter and start moving towards it.. no matter where its placed as long as its within the 5m radius area of detection.