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!
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.
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
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.
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
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.
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!
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...