automotive power window regulator test system using CompactDAQ

[brandi]

I am currently trying to do some test automation (control + data acquisition) for an automotive power window regulator test stand using NI compact DAQ platform.  Basically there’s a car door module(or up to 4 doors at a time) and my compact daq is supposed to control the motor to go up and down continuously (theres a time delay between up and down motion) for about 30,000 cycles all the while logging current and voltage data as well. I am a labview Noob but willing to learn.

Modules being used

•    N.I 9178 chassis

•    NI 9205 Analog out

•    NI 9476 Digital Out

•    NI 9425 Digital In

•    NI 9421 Timer module

•  NI industrial controller 3110 Fan-less & Rugged Industrial Controller, dual core with 80GB internal HDD

Sensors + Actuators

• Hall effect current sensor
• Voltage Transducers
• Photo Sensors
• Reversing contactors

I believe it can be done using the modules mentioned as I have an application note on NI for the exact same situation (Using LabVIEW and DAQ to Create a Car Window Regulator Testing System http://sine.ni.com/cs/app/doc/p/id/cs-13517). However the application note just provides a summary with no details.

I have already ordered the parts mentioned above and while waiting (can’t change to cRio), I am doing some back ground study etc. to understand things better and I have gone through a lot of discussion forums before deciding to post this… any comments are welcome… I hope to post more specific questions when my hardware comes in and I start developing the code.

A] The Basic test sequence for one door

On a real car door module sensors are placed at strategic points.  Photo sensor placed at glass top dead position and bottom dead position of the glass.

1. Photo sensor detects glass at top dead position (digital input)
2. Drive relay to turn window motor anticlockwise (to roll glass down)digital output
3. Photo sensor detects glass down position.
4. 5 second delay timer (timer needs to be a user input)
5. Drive relay to turn window motor clockwise (to roll glass up)
6. Photo sensor detects glass at top position.
7. 5 second delay timer.
8. Increment cycle count.
9. Repeat from 1.

B] Requirements

1. User inputs number of cycles to complete at a time
2. User able to add up to 4 doors to the test sequence at a time. But not while a test is running
3. Real time display of current voltage speed etc from sensors
4. Real time plot of current and voltage (graph must refresh after each cycle)
5. Complete datalogging of all parameters for 30,000 cycles (TDMS or write to measurement file) in simple row column format
6. After n number of cycles (e.g. 1, 100, 500,1000..etc) a table is updated showing certain parameters like max current for up and down, travelling speed etc.
7. Customized Report generation in Microsoft Excel for an overall test report summary.

C] Current Concerns

1. Software timing sequence or Hardware timing sequence? : Is software (pc) timer reliable to run for 30,000 cycles or more? Hardware timing is more reliable? If yes, can we use the timers in the cDAQ chassis (PFI) or use the NI 9421 Timer module? I need some examples on how to do this.

2. How to create a software trigger to add doors to the test. For example, to test one door, 3 Analog Input channels, 2 Digital Out Channels and 2 Digital Input Channel required. If the user wants to test 2 doors at a time, some input (button, radio button, input prompt) is provided which should trigger more analog ,digital channels as mentioned above.  Only the channels which are required should be triggered to avoid unnecessary polling .

3. What if the pc shuts down mistakenly. 

I have created a sample interface to give u an idea of wat i am trying to do ( i have not wired it up though).

[brandi]

sorry if the post is too long... just wanted to decribe the whole project in a single post.