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Author Topic: need help with a project  (Read 1014 times)

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Offline Cavazos.FTopic starter

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need help with a project
« on: March 21, 2011, 09:23:09 AM »
Hi I'm new to society of robots, and robots at all. I was always fascinated about this topic and started a computer science mayor because of this. But I'm totally blank, i know the most basic things just like what a circuit is, batteries, resistors, etc. however I haven't made any robot and lack the programming knowledge and all that. Well that's not the point.

The point is that I'm in a "freshman" project from college. We are trying to design a pedal depressor for a music mayor pianist that is disabled. The main idea is making a biteswitch using a transmitter and receiver and have an actuator press the pedal. We already got a bite switch thanks to a member. we are looking for a transmitter and receiver and already ordered an actuator based on the force needed, length timing etc.

The serious thing is that we don't know anything of automation, and little of everything else. I was about to start with the "50 bucks robot that is not 50 bucks" when we had this issue. We are totally blank on this subject, but I'm really willing to learn about everything, if you could instruct/help/advise/anything i would appreciate it a lot!

This is the actuator we bought
http://progressiveautomations.com/tubular-high-speed-linear-actuator-pa-15-/tubular-high-speed-linear-actuator-stroke-size-1-force-33-lbs-speed-5-51-/sec-/prod_129.html

We need to make it go certain length, and while the switch is still pressed keep pressing the pedal, when the switch is released make it go backwards.


Offline Soeren

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Re: need help with a project
« Reply #1 on: March 22, 2011, 08:36:56 PM »
Hi,

We are trying to design a pedal depressor for a music mayor pianist that is disabled. The main idea is making a biteswitch using a transmitter and receiver and have an actuator press the pedal. We already got a bite switch thanks to a member. we are looking for a transmitter and receiver and already ordered an actuator based on the force needed, length timing etc.
What is the output from the switch, discrete or binary?

For being useful as a piano pedal commander, you need to be able to translate the parameters velocity, timing and distance the pedal is... errm... bit down.

If the bite switch is indeed a switch (i.e. binary), rather than a linear sensor, then you might wanna consider a blow sensor (where you have a tube in your mouth) for the job.


The serious thing is that we don't know anything of automation, and little of everything else.
Oh my, you're in for a steep curve then.


We are totally blank on this subject, but I'm really willing to learn about everything, if you could instruct/help/advise/anything i would appreciate it a lot!
Willing's good, but it also matters whether the abilities of self tutoring is in place, as you'll need to pick up a lot yourself, to follow any help you get. It would be way too long winded to teach you all the underlying basics.


We need to make it go certain length, and while the switch is still pressed keep pressing the pedal, when the switch is released make it go backwards.
You'll need an H-bridge driving the actuator, to be able to make it go back and forth.

You'll need a sensor of sorts on the actuator, to tell the receiver/actuator circuit how far the pedal is pressed, so you can turn the actuator into a linear servo, to replicate the pianists jaw movement.

How much funding do you have for this project?
Does any of you have any experience in electronics construction, measuring, soldering, etc?
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline Cavazos.FTopic starter

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Re: need help with a project
« Reply #2 on: March 23, 2011, 05:57:00 PM »
What is the output from the switch, discrete or binary?
How much funding do you have for this project?
Does any of you have any experience in electronics construction, measuring, soldering, etc?
It is a binary switch, we just want to make version 0.1 and not messing with a lot of things.  because we need to show something tangible to get funding and improve the project. And also we have a little deadline kicking our buts. that's why we are not getting into a linear sensor, right now. well just keep it simple this time



A new member who has  experience with electronics came with a proto board having a circuit with a not gate so when the switch was off one led was on, when the switch was on that led turned off and turned on another one. like this one


or at least that's how he said it was. I suppose this could work right?, of course powering the leds/motor with a separate battery and adding the transmitter/receiver, but I think that's pretty good for our go/retract design.

what do you think?
« Last Edit: March 23, 2011, 05:58:45 PM by Cavazos.F »

Offline Soeren

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Re: need help with a project
« Reply #3 on: March 24, 2011, 11:35:38 PM »
Hi,

That won't retract the actuator.
As I wrote... You'll need an H-bridge driving the actuator, to be able to make it go back and forth.

If the deadline has got fangs, you could get away with using 2 relays instead of the H-bridge, but I don't thing a pianist will be too happy having a relay going *klonk-klonk* when hes playing Piano Pianissimo, so do this as a time saver, only if absolutely needed.
It will have to be a SPDT relay (Single Pole, Double Throw) or better and each contact should be able to stand the motor current (diodes over each contact will help a lot).

Do you need help on how to control 2 relays from the bite switch?
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

 


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