Car parking control and monitoring

[LasJ]

Hi all,

I'm wondering if you can help me, I have a car parking model I want to control and monitor with labview but I don't know where to start. If has a barrier and a senor, how can I get to work with labview?

[PatrickLye]

What kind of sensor(s)? What signals do they generate? Are there any outputs such as lifting gate, turning on lights, etc...

[_Bryan]

Question 1:  Is this a school project?

Question 2:  Have you used LabVIEW before?  If not, have you done any of the free online tutorials/training?

Question 3:  What have you done so far?  People are more willing to help if you have already done some work on your own and show it to us.

And of course anybody wanting to help would need much more information about what you have (equipment) and what exactly you want the program to do.  To start with you mention a barrier and a sensor.  What barrier and what sensor?  What is the output of each?  Then you can figure out how to get that output into LabVIEW.  Then you will need to decide what the program is supposed to do with the input from the barrier and sensor and any other logic you might need.

It could be a simple project, but even simple projects need some type of planning.

[LasJ]

Thanks for your reply, im just going to give you few details maybe you can send me to the right direction. I have been looking everywhere but can't find anything similar where I can say i know where to start and where to go with it.

The model has is 23 spaces car park and has LCD display to display the infomation to drivers goin in only, the message should number of spaces or full no space.

4 sensor (1,2,3,4)

ticket

paid

help in (this is emergency in)

help out (emergency emergency out)

lihgt in

light out

barrier up

Barrier down

it uses a stepper motor for the barrier which has DRIVE IN 1, DRIVE IN 2, DRIVE IN 3, DRIVE IN 4 for the DAQ connections

This is how is should operate:

CAR IN

If the ticket botton is pressed the lights in, should turn green and car goes in,  if sensor  3 beam is broken the barrier should open, and should close when sensor 2 beam is broken and the light in should change to red. when sensor 1 beam is broken the count should be ( - 1)

CAR OUT

If the paid botton is pressed the lights out, should turn green and car goes out,  if sensor  2 beam is broken the barrier should open, and should close when sensor 3 beam is broken and the light out should change to red. when sensor 4 beam is broken the count should be (+ 1 )

HELP IN / HELP OUT

In emergency ( help in / help out ) the barrier should be manually control with a switch by the controller.

It is a one way system, if a car is coming out a car cannot go in and /  if a car is goin in a car cannot go out.

I hope you understand what i am trying to explain and any suggestions will be much appreciated.

Thanks

[PatrickLye]

Do you have Visio or anything similar?

A simple project like this could be done directly in code, but it is a good idea to do state diagrams or flow charts to see where to go.

It looks like you have Display, Gate, Enter Light, ticket, and Exit light for outputs.

It looks like you have Emergency in, Emergency out, Entrance area entrance sensor, Entrance area exit sensor, Exit area entrance sensor, Exit area exit sensor.

Simply pick an output and model out all of the items that can make it operate, and when more than one case can make any one event happen as your logic grows you have a set of parallel logic to an OR gate to make the single event happen.

Your sign is a simple case statement with a text value in two cases. IF cars in parking garage is less than 23 you convert the number to a string and feed it out of the case statement and into the sign display. IF cars parking in garage are greater than or equal to 23 a "Full" string would be output on the same wire to the sign.

If you have no software available you can do the same sort of flow or state diagrams on paper. Normally it is a simple thing to work from outputs to analyze the inputs that make things happen.

Sometimes straight boolean logic gets to be a pain and you need to step it up into a state machine design. You should look at the training available under the Tutorials link in the right column on the NI Forum main page.

Once you have your design down on paper or on the computer it is easy to use this to apply logic in your program if you understand how to use LabVIEW.

What kind of logic used may be driven by the class you're in. If you are studying boolean and you use state machines your professor probably won't like that.

Like I said before it is sometimes simple enough that you just put down an output and the inputs that affect it. Then you can wire in a few easy items to get what you need, but starting out in at least some sort of logical design instead will get you to understand things better when you hit harder to achieve goals.

[LasJ]

Yes i understand i have inputs and outputs But is it neccessary to have two seperate DAQ ASSISTANCE in the program to assign one for input and the other for the output?

[LasJ]

Hi all I'm stuck in a section of a code, and wondering if can anyone tell me how to de-energise a stepper motor using barrier up and down sensors, with a case structure?