How to sense the beginning and end of a ramp?

Community General Discussions
1

Hi guys,

I am a complete novice to building robots, yet have been tasked with making one for my Mechanical Engineering degree. I find it very interesting but am struggling to find the right sensors for the tasks it needs to do.

The robot will follow a white line on the ground using LEDs and LDRs going to a Wheatstone Bridge, and the output will control the Differential drive. I feel fairly comfortable (read: not really at all) with this section, but then the robot needs to sense a ramp, drive up it and sense when it reaches the top and come to a halt.

How would one implement this using tactile sensors? 

We are using an Arduino Uno as the micro controller.

Thanks!!

(I will probably be back in the future asking for more help!)

2

Accellerometer. It can sense

Accellerometer. It can sense if the robot it’s tilted; if it’s in plain it will output something like 0;0;9.8 , if it is tilted (like going up a ramp) it will output 0;3;7.9 (if y axis it’s pointed toward the ramp), then when you get 0;0;9.8 you have finished the ramp. It can also detect the orientation of the robot when it is on the ramp.

Search ADXL335 module, there are many chips, but usually these are the cheapest (2-10dollars).

3

Welcome!

Tilt switches usually look the same as capacitors, and make a little sound when they are triggered.

4

Ramp ending

Is there a flat landing at the end of ramp (as everyone seems to have assumed), or does it just end.  In which case a microswitch could detect the end of ramp, enabling you to stop or reverse as needed.

5

Hmmm. How about a sonar or
Hmmm. How about a sonar or IR sensor in front pointed at an angle to detect the end of the ramp. This is assuming that the ramp goes up and then ends.

Also, and this is just nitpicking, but is your robot has two drive wheels powered independently along with one or more casters for stability, then the robot has differential steering rather than a differential drive.

6

I would have gone with

I would have gone with either OddBots proposed solution too, simple, cheap, elegant and easy. just like Whiskers on a cat!

…or next would have been a downward facing IR proximity sensor.