How to design an obstacle detector for a robot?

[semiconductor]

I want to design a circuit for my robot. It let the robot know that is there any obstacle in front of the robot?

I right now do not know where to begin.
Is there anybody can recommend me some ideas as well as internet links related to this project. If some one have done something similar to this, it would be kind of you to upload it here!

Thank you beforehand!

 

[penrico]

Re: obstacle detector

Time ago I make a small robot that turn left or right upon is an obstacle in front of it, the idea is simple:

I use a LM567 (PLL tone detector) for detect signals from a phototransistor connected like this:

....... VCC
........|
........\
......../...22Kohm
.......|----------------------------||----------> Out signal to pin 3 LM567
.......\
........\| <-- Phototransistor
......../|
......./
......|
.....GND

And, use the same LM567 in pin 5 to generate the transmited frecuency connected to and infrared LED.
It work good, upon the color of the obstacle you can detect distances from 5cm (for black objects) to 30cm or more for white objects. Using pin 8 you have the detection signal.

Hope it helps, download the LM567 datasheet from www.national.com

Center frecuency for LM567 is good in 1Khz or less.

 

[meqwerty]

Re: obstacle detector

obstacle detection is rather difficult. There was a unmanned vehicle competition a few weeks ago. and nobody won the grand prize of 1m. can check out tomshardware for more details

 

[wt70707]

Re: obstacle detector

I have ever done that using an embedded switch in the front arm of the Romotec-like Mobile vehicle. It is just a switch gives close or open signal. It is simple and cheap.

 

[trigger74]

obstacle detector

For simplicity, I think you can first tried with infrared circuits. Their circuits are all over the internet.

 

[joerieg]

Re: obstacle detector

another ideas:
1. use ultrasonic, there are a lot schematic on the net. ultrasonic doesn't depend on the light.
2. use whisker that combine with limit switch, if your whisker found obstacle that it will trigger limit switch, so you can ask your robot to turn around

 

[manu]

Re: obstacle detector

You must 'linearise' your photodiode, look this document :
**broken link removed**

And simply use a trigger, or a ADC which you will send data signal.

Regards,

Manu

 

[JFDuval]

Re: obstacle detector

Hello!

Another simple and efficace way is to use all-built modules, like the ones that are used in TV and VCRs. You just need to modulate an IR led (can be donne by a 555 or a uC) at the same frequencies that the module is made for. Personnaly, I use 33khz ones but the majority are 38khz. Those modules are three pins. Gnd +V and Out.

 

[faroo28]

Re: obstacle detector

look at the following website
http://www.laseroptronix.se/airpor/obstacledet.html

Sounds interesting, If something similar can be made for home made robots or for home security systems.

Another website which contain some hints for different sensors is
**broken link removed**

 

[banh]

Re: obstacle detector

I want to design a circuit for my robot. It let the robot know that is there any obstacle in front of the robot?

I right now do not know where to begin.
Is there anybody can recommend me some ideas as well as internet links related to this project. If some one have done something similar to this, it would be kind of you to upload it here!

Thank you beforehand!

i think the simplest way is to use infrared & phototransistor & microcontroller adc input.

 

[rx5]

obstacle detector

very hard to design! ive done one.. IR modulated.. i used 2 commercial IR detector(sony)... as a sort of prox detector... but i only used 1 clock/IR modulator source... i think i need to experiment on where to put those two detectors..they are SO sensitive...

 

[Saeedafzalkhan]

Re: obstacle detector

h**p://focus.ti.com/lit/ml/slab039b/slab039b.pdf


/ Warning

Stop spamming. Read topic before posting! This link is already posted earlier in this topic!

- ME

 

[yangxh]

obstacle detector

You may use ultrasonic sensors,it can sense further.
For you Ithink 1m may long enough.you can get it from some market.

 

[gidimiz]

obstacle detector

Hi,

Have a look at this link:
http://zuff.info/SharpGP2D12_E.html

Good luck.

 

[ME]

obstacle detector

This topic is more than one year old. He has probably found a solution by now?
But it would be nice if he cared to post his results.

 

[viveklengade]

Re: obstacle detector

i have done obstacle detection for my project it will give max range of 2 meter try for that. if u want it i will gve to u?