Help with choosing the right hardware

[IMcata]

Hello,

I would like to know what hardware sollutions from NI are best suited for my Master's degree project, which is a motorized crane for a video camera (basically a robotic arm with 5 axes). What I need is something to control my 5 motors (DC/stepper) - both in position and velocity and also need some Digital inputs available for different sensors. In my previous project, I have succesfully built a motorized slider for camera (only 3 axes - 2 rcservo for pan/tilt and a DC motor for translation which was controlled in position) and I used Arduino development board to control it, encountering difficulties for controlling my entire system. In this upgraded version of the crane, I thought that NI hardware are more reliable, and I want to find something to match my application requirements. I just need something to control my motors using Labview, as I will make my own drivers for them (also something affordable for a student as the motion control modules are way out my bugdet).

On the other hand, I would also like to control my system from a smartphone and I was wondering why Labview has implemented applications for Android and Apple, but not Windows Phone? Are there policy issues or just not yet implemented? If not, I would gladly develop an application for WindowsPhone8, as it would help me remotly control my crane.

Thank you in advance,

Catalin Ionita

"Politehnica" University of Bucharest

[Joel-P]

Hello Catalin,

There are a few options that are available for this application, I'll start with the simplest hardware with the most difficult software and then progress from there.

The simplest implementation that I can think of would be a high channel count digital I/O device, where you power a custom H-Bridge or similar motor driving circuit. Based on a 6 or 4 pole stepper motor this would translate to 20-30 digital channels. Something as small as a NI USB-6504 (24-ch, 8.5mA) would work with very low performance. This implementation would only have software timed digital output with a significant amount of jitter and variability, as well as the 8.5mA max current drive per channel which would require extremely high input impedance on the drive circuit. 

The next step up in implementation would be a digital I/O device with Hardware timing such as a NI PCIe-6321 or a NI PCIe-6323. These cards will allow a buffered digital output which will significantly reduce jitter and increase the performance of this control.

Both of the above methods would require you to program the motion control for the stepper motors, and would also require an external drive for providing the power to the stepper. This could be something as simple as a custom built H-Bridge, a simple stepper motor driver such as this one available from sparkfun.com: Big Easy Driver.

The next option would be using the motion modules such as a NI 9501. This would be the most complicated hardware, however this would enable you to use the National Instruments SoftMotion Module for programming instead of writing all the code from scratch.

In regards to the implementation for LabVIEW implementation for Windows Phone, I am unsure of whether this will or will not be implemented. Please feel free to post your ideas on implementation on the NI Idea Exchange, and thanks for the feedback!

Cheers,

Joel