Following an object with ultrasonic sensor

I made some topic days ago wondering about some "challanges" for our arduino robot.

We bought this one: http://www.makeblock.cc/starter-robot-kit/

It got an ultrasonic sensor in the front as you can see on the picture( it is the only sensor).

So we thought we should try to program the robot, either following an other robot (that has an preprogrammed route) or follwing an object like a hand or stick or something similair.

So how I thought we had to do if the robot should be able to manage this was:

  1. have 3 distance measuring sensors, like the ultrasonic. One in the front and one on both sides of the robot.

  2. the robot is then programmed to: if the front sensor recognize an object that's within the range ( for example 20 cm) the robot move forward, if it isn't the robot stops.
    If the robot sense a object that's within 20 cm on the sides of it with the sensors placed there the robot turn to that side, like if the left sensor notice an object within reach the robot turn left until the front sensor recognizes and then the robot again starts moving forward?

Am I completely wrong about this ( I am a beginner)?

I was looking at makeblocks product video for the starter kit were the show a little bit when the robot is following the hand. You can see it here

But on that video the robot only has the one ultrasonic sensor in the front so how do they manage to program it following the hand? like how do the robot know if the hans is on the left or right side?

The robot in the video isn't following a hand, it is stopping or reversing the drive motors when it detects a hand or wall.

What you want to google is "follow me robot" or "Stalker bot".

Here are some examples

A more advanced ways is to use a camera and OpenCV.

mjalaly:
The robot in the video isn't following a hand, it is stopping or reversing the drive motors when it detects a hand or wall.

What you want to google is "follow me robot" or "Stalker bot".

Here are some examples
The Stalker 'Bot - Make:
http://www.instructables.com/id/How-to-make-an-object-following-robot-the-stalkerb/?ALLSTEPS

A more advanced ways is to use a camera and OpenCV.

Thank you, that was some good tips, then my idea would work, even with only two sensors.

Yeah I am not so advanced, what would be fun is a scanning sensor maybe goin back and forth.

hey , you done wit this project , i have to make same robot for the school , i tink same type of robot but i have to make it wit PID :(( so is more complicate , sorry for my engl

i have to make same robot for the school

I'm pretty sure that excludes just using someone else's code.