Stundent Project- Remote Controlled Microphone Stand

[mish]

Hey guys i am working on a student project which involves putting together a business plan for a product. the product i have chosen is a Remote controlled microphone stand for sound recording facilities. If anyone has any ideas on what i might use to put something like this together snd how much it would cost please share them.

Basically the stand will have two moving parts, the height of the centrepiece, and the microphone clip which is at the end of an arm. This ideally would be hinged on a ball and socket. but thats about it. I am totally new to this area of motion control so anything would be helpfull thanks!

[Ali84]

Do you have a diagram of your system that you could send ? Also, if you are planning on using LabView for the control, it might be helpful if you tell us how are you planning to send the signal (DAQ? Port? etc).

[mish]

The movements that need to take place are the hieght which is adjusted next to the red sticky band on the image. The next is the arm just above it which needs to move forward and back, maybe 4 inches. Lastly is the mic clip up the top which should be hinged on a ball and socket.

I dont really know much more about it so an help will help... cheers~

[mish]

oh yeah and an another thing i am wondering is that when motion control devices are not moving does the circuitry still have power flowing through it? because that might cause electromagnetic buzzing while recording which doesnt help.

[Ali84]

As for your question about the devices still having power flowing through them it really depends on the device your planning to use. Should you decide upon stepper motors (which I recommend) the IC drivers usually have an option to deactivate (no flow) and another one for pausing (constant flow). As for the second option, it is used to mantain the motor in one position despite the load. A DC voltage is sent, though its value doesn't vary until you change the mode.

I suggest you use a stepper at least for the forward-backward movement since it allows a high level of control and inertia is not a problem. For controlling such a motor from Labview, take a look at this page: http://etidweb.tamu.edu/projects/labview/stepper/vi.htm

As for the ball and socket I suppose you chose that mechanism because you need a 360° movility. Perhaps you want to consider using a ball bearing instead, it would be easier to control, mechanically speaking.

Please let me know if you had other mechanisms in mind for moving your system.

Cheers.

Ali

[jamrite]

Mish,

Ali is absolutely right in recommending stepper motors. They are usually the best (also the cheapest) means of motion and position control. However, in order for the stepper to maintain position (i am assuming that you would need it to) it needs to be energized the whole time. This could possibly be circumvented by having the user clamp down the position after it is set automatically. I can think of many ways in which this can be done (manually or programmatically) and I would be happy to explain if you want me to.

National Instruments has products that help you develop a whole stepper control system. Here is a link if you are interested in the details: http://zone.ni.com/devzone/cda/tut/p/id/4165

Also, in order to convert the rotational motion of the motors to linear motion, you need a "linear stage". You would need a really small stage, the likes of which are used in benchtop microscopes. Look at this website for such products - http://www.mechatronictechniques.com/products. To perform this translation from rotational to linear motion, stages use the principle of a "ball screw". To learn more about these, you can read this: http://en.wikipedia.org/wiki/Ball_screw.

Hope this information helps.

Jaidev Amrite

Applications Engineer,

National Instruments

[mish]

Awesome, that helps a lot!

I have the basic idea which is all i need at this stage. I would like to know more about how i could create a system that will stop the flow of current when idle and still hold its position. Ideally the engineer should not have to adjust anything on the mic stand. thanks

[jamrite]

Mish,

You can use some sort of "solenoid" to hold poition, once its set by the stage.  Take a look at this link: http://www.thesolenoidcompany.com/bi-stable.php. These solenoids will lock into place once energized; you can then remove power to the motor. 

Jaidev Amrite

Applications Engineer

National Instruments