Electrical Engineering & Electronics Design

I am not an expert on this topic however I would start by looking at stepper motor solenoid valves to precisely control air flow to your pneumatic cylinder. The valve can then easily be controlled by a simple stepper motor driver and arduino micro controller setup. You can then use simple forward and backward stepper motor code to control your pneumatic cylinder with precision.

How big is your required stroke? You might be able to accomplish what you want with some gearing unless you already have your actuator.

If you already have a linear actuator just use a sin(theta) function and vary theta linearly

If you are doing this without a microcontroller let me know, you would likely need an oscillator circuit and a voltage follower opamp configuration

thanks for replying , i have thought about a part of what you said but i didn t get what you want to say about how the valve (solenoid ) can be controlled by a stepper motor can you explain more please ?

thanks again

thanks for replying

the stroke must be controlable (extends amplitude ) , i will use an arduino microcontroller with a relay but if there are better ways i m readdy to change it

what do you think which way is more simple ?

and i hope you can explain me more about the sin(theta) because the idea is exactly like you said but how can i do that function in real please?

Hi Amy,

Firstly have you acquired an actuator yet? If so, what kind?

Is this what you are trying to do? https://www.youtube.com/watch?v=SwYYysxuIfA

To control any motor via arduino you should open the IDE and click include to add in a new header file which makes motor/actuator control easy (e.g. servo, stepper, etc)

The math header file should have trigonometry functions like sin, cos, and tan.

To linearly increment you can just define a variable equal to zero initially (x)

to increase x by one you can type

x++;

or

x = x+1:

this should be done in a loop so that it increases in value by one every iteration of the loop.

To change the rate just change the scaling of x

sin(x*scalingfactor)

Let me know if you have any more questions

Hello again,

Pneumatic cylinders are usually controlled by air. For this you need to control the air you are pushing in and out of the cylinder. They are not really designed for precision sine wave movement however can be controlled by stepper motor solenoid valve to control the air flow going in and out.

A much better and more precise method is to use a linear actuator or linear rail controlled in exactly the same way by a single stepper motor.

Just look up arduino stepper motor on how to control it.

You can buy these off Ebay good luck

thank you very much it s very useful for me

about the actuator i will give what kind if it and exactly what i wanna make is shomwn in this video

https://www.youtube.com/watch?v=ilE2GfB0XPI

yeah you right but my problem with stepper motors and electric actuator is the low speed , ineed a very high speen for the actuator

https://www.youtube.com/watch?v=ilE2GfB0XPI

in this video you can see exactly what i want

I would check out the link below for ways to cause linear actuation.

https://www.servocity.com/motion-components/linear-motion

You can make or buy very fast linear actuators that work with stepper and electric motors. It really just depends on the gearing. The real limitation is weight and expense.

You could also make something similar to a locomotive engine which has a bar attached to a drive wheel to cause sinusoidal linear motion. https://en.wikipedia.org/wiki/Driving_wheel

So you want a servo controlled pneumatic cylinder setup.

These are readily available on the market.

https://www.youtube.com/watch?v=4hIlLzCneDg

https://www.enfieldtech.com/portfolio/accurate-force-control

it s exactly what i want

thank yuo very much

have a good day :)

thanks :)

have a good day

Glad to help. Good luck Amytech