I need a little help ... 4 wheel robot

[occult5]

Hy everybody. I´m here because i need a little help with a robot project. I started to build one from scratch...made an proximity sensor with IR, bought 2 motors 6V and i was wondering... I found a lego car with steering direction. i think one motor for each side 1 for the wright side and one for the left side and one sensor for each side two, when a object stands in front-left side he turns right and ther other way around. Now my problem ... if i´m using a IR proximity sensor and a normal chassis with no steering wheels how can i make the robot turn when encountering an object in front of him ? How about using the Lego chassis with the steering wheels? Can anybody help me find the wright circuits to make this robot work?
Here is the lego car: **broken link removed**
Here is the proximity sensor: **broken link removed**
Ah and please be gentil i´m just a stundent and my professor dosen´t have any ideea

 

[ericgibbs]

Hy everybody. I´m here because i need a little help with a robot project. I started to build one from scratch...made an proximity sensor with IR, bought 2 motors 6V and i was wondering... I found a lego car with steering direction. i think one motor for each side 1 for the wright side and one for the left side and one sensor for each side two, when a object stands in front-left side he turns right and ther other way around. Now my problem ... if i´m using a IR proximity sensor and a normal chassis with no steering wheels how can i make the robot turn when encountering an object in front of him ? How about using the Lego chassis with the steering wheels? Can anybody help me find the wright circuits to make this robot work?
Here is the lego car: **broken link removed**
Here is the proximity sensor: **broken link removed**
Ah and please be gentil i´m just a stundent and my professor dosen´t have any ideea

hi,
As you have individual control over each motor, [ assuming also its a rear wheel drive], drive one wheel forward and the other in reverse.

That should drag the front end around providing there is not too much friction under the front wheels.

 

[occult5]

I was thinking about using the front wheels with the motors alowing the sensor more time of reacting and stop the wheel with no object in front

 

[ericgibbs]

I was thinking about using the front wheels with the motors alowing the sensor more time of reacting and stop the wheel with no object in front

A solution would be, when you contact an object dead ahead, reverse a few steps, then drive the motors in opposite rotation.

If there is more traction on the driven wheels compared to the front wheels the robot will spin around.

Do you follow that OK.?

 

[occult5]

Ok im trying let me get home and draw what i want to happer and what i understoud xD Cause im waiting for the bus now and im on my mobile.But what do you think?Should i use like the base of a normal toy car that dosen't have the whdels change direction?And can anybody explain how dose my ir sensor dosse act with the wheels?Or controle them?

 

[ericgibbs]

Ok im trying let me get home and draw what i want to happer and what i understoud xD Cause im waiting for the bus now and im on my mobile.But what do you think?Should i use like the base of a normal toy car that dosen't have the whdels change direction?And can anybody explain how dose my ir sensor dosse act with the wheels?Or controle them?

hi,
You will have to build an electronic controller in order to control the motors.

This can be made from integrated circuits or from a micro controller,

How much experience do you have with electronics.?
I would suggest that you consider buying a simple robotics kit.

 

[blueroomelectronics]

A Lego Mindstorms NXT is more likely what you're after.
**broken link removed**

 

[occult5]

ok i have a little study in electronics but i can handle it ... i searched the web for some bot motor controller ...found some but really that are for PRO's geez the schematiques scared the devil out of me huge list of components and so on and so on ... the only thing i didn't found was a simple schematiq with 2 motors that can brake separatly with the help of the IR sensor :S

 

[occult5]

i found that a local store here near my home sells the L293C IC witch is a H-bridge motor driver chip.can anybody help with a little circuit for 2 motors only doing forward and stop for each motor? without the sensor witch i will integrate later into the circuit.thanks

 

[ericgibbs]

i found that a local store here near my home sells the L293C IC witch is a H-bridge motor driver chip.can anybody help with a little circuit for 2 motors only doing forward and stop for each motor? without the sensor witch i will integrate later into the circuit.thanks

hi,
Look at these links:


https://www.robotroom.com/HBridge.html

https://www.robotroom.com/BipolarHBridge.html

https://www.google.co.uk/search?hl=en&q=L298+motor+drive+circuits&btnG=Search

https://www.electro-tech-online.com/custompdfs/2008/04/l298.pdf

 

[occult5]

Yeai i found one with the L293b and bohgth 2 over the net cause my sensor ir normaly high and i only need him to go forward and stop

 

[NightFalcon90909]

i found that a local store here near my home sells the L293C IC witch is a H-bridge motor driver chip.can anybody help with a little circuit for 2 motors only doing forward and stop for each motor

Ok, I just skimmed this, so I might be completely missing something. If so, ignore this.

If you only want the motor's to stop and go forwards, you don't need an H-Bridge... just supply current, and stop current.

 

[occult5]

this is what i want ... i'm bad at drawing but here this is what i have and want to happen **broken link removed**

 

[occult5]

oh and i found a little circuit ... i just made an order for the IC but i don't know if that works in my case **broken link removed**

 

[Krumlink]

Does it absolutely have to be 4 wheeled? Just have a 2 wheel bot with a caster in the front, if the conditions allow or one.

Tank drive is what you want then.

 

[occult5]

yeah tank driver ... i want a 4 wheel cause im gonna put a battery charger in the back and plug him in to recharge the batteries when they are gone so its a little weight on him and i think 4 wheels keep him more stable don't you think?

 

[occult5]

i just woked up from a dream and asked myself.why the heck do i need a controller ? i just use my sensor directly to the motor cause when an object come to his trajectory he cuts the power and so he will stop the the motor. i don't need a fancy IC circuit and owsome controller it's still a robot

 

[ericgibbs]

i just woked up from a dream and asked myself.why the heck do i need a controller ? i just use my sensor directly to the motor cause when an object come to his trajectory he cuts the power and so he will stop the the motor. i don't need a fancy IC circuit and owsome controller it's still a robot

BUT,
This is not what you asked in your first post.

You wanted a reversing 4 wheel robot.

You are going to get bored very quickly with a 'robot?' that hits an object and stops.
A clockwork driven shop toy can do that,!

Dont downgrade your original idea just because its difficult to do,,,, thats the whole point of a challenge, to help you learn..

 

[occult5]

i know i thank you but i am gonna try first that way whireing the motors with the sensor and see how it works ... while im waitng for the L239 IC then i`ll try to make him reverse.yeah it is a 4 wheeld robot but it has only 2 motors in the front i think its more power that putting them on the back

 

[occult5]

hey any pro around here can help me with a little problem with my bot? i apply 5v to the sensor ... but on the output i only have 1.5V.thats obvious that it's not enough to power one motor.any idea how can i amplify from 1.5V to at least 5V again? :S