Simple and novel idea for machine control
John M Bond
Posts: 29
Say you have a factory with 150 individual machines. It is impossible for the shop-floor management to know what each machine is doing. Because of this, even a good batch processing factory seldom get's their machine efficiency above 60%. The accountants tell us that if you could improve this by just 10%, you would more than double the end of year profits, Oh what to do, what to do?
Say you have a bunch of indicator lamps on each machine, showing the foreman what the machine was doing. Say you used green for producing, red for quality problems, yellow for machine problems, Blue for shortage of parts and white for operator missing. You'd probably need a column of about 6 or 8 lamps to be effective.
I say the basic idea is novel but it's been used before, this is just a "better mousetrap", Ford first tried it in about 1955 and the Japanese Auto makers demand them on their suppliers machines. The Japanese systems have only two colours, green or red. If it is red, the foreman must go and sort out the problem. With 10 or 15 red lamps on at a time, which does he tackle first.
A Green lamp is even worse, the machine may be running, but at 30% of its designed speed. You may as well switch it off but it has got its green light.
I have made a small, discreet and inexpensive light column. I used a big RGB LED which can produce a bright, annoying flash rate to attract attention, or a subtle relaxing colour when all is OK. The column is smaller than a fifth of the size of the old unit yet is able to display dozen's of different colours and flash rates to indicate the state of each individual machine.
I control each colour using a one byte PWM signal. This means the colours are very similar to the RGB colours on your computer screen. This makes choosing and setting up individual colours much easier. There is still a bit of tweaking needed.
Everything about the light column is variable, colour, flash, brightness and you can flash two colours at the same time, for example red-green-red-green-red...
You're collecting the production information for the column so why not also use it to display the number of items produced in the last hour and the number of rejects. The foreman can now see where his production problems are and how severe they are - for each individual machine.
Add a RS485 or Wireless link or network cable and the management big cheeses can sit in their offices and watch how their factory is running.
I have done production control before, first using PCs which weren't rugged enough then PLC which were expensive and lacked the power. I have done this type of system twice with Parallax products and both systems are still working. The trouble with all my previous systems and all those I have studied is that none help the foreman to manage his machines better.
The photo doesn't do the light column Justice, the colours are amazing!!!
This project uses a (Very good) Parallax legacy controller. The controller is in the run-out phase so I'm not going to post schematics, software etc (if anyone want's it, they are welcome but I think it may be better to use the current stuff). The idea would work well with either Stamps or Propellers.
As usual, the reason I am here is I had a technical query, nothing to do with the controller, and the forum response was almost instantaneous. This is a very important aspect of Parallax products. The time and frustration you save is worth gold. I then saw a concern over how we never post our projects - fair criticism...
Say you have a bunch of indicator lamps on each machine, showing the foreman what the machine was doing. Say you used green for producing, red for quality problems, yellow for machine problems, Blue for shortage of parts and white for operator missing. You'd probably need a column of about 6 or 8 lamps to be effective.
I say the basic idea is novel but it's been used before, this is just a "better mousetrap", Ford first tried it in about 1955 and the Japanese Auto makers demand them on their suppliers machines. The Japanese systems have only two colours, green or red. If it is red, the foreman must go and sort out the problem. With 10 or 15 red lamps on at a time, which does he tackle first.
A Green lamp is even worse, the machine may be running, but at 30% of its designed speed. You may as well switch it off but it has got its green light.
I have made a small, discreet and inexpensive light column. I used a big RGB LED which can produce a bright, annoying flash rate to attract attention, or a subtle relaxing colour when all is OK. The column is smaller than a fifth of the size of the old unit yet is able to display dozen's of different colours and flash rates to indicate the state of each individual machine.
I control each colour using a one byte PWM signal. This means the colours are very similar to the RGB colours on your computer screen. This makes choosing and setting up individual colours much easier. There is still a bit of tweaking needed.
Everything about the light column is variable, colour, flash, brightness and you can flash two colours at the same time, for example red-green-red-green-red...
You're collecting the production information for the column so why not also use it to display the number of items produced in the last hour and the number of rejects. The foreman can now see where his production problems are and how severe they are - for each individual machine.
Add a RS485 or Wireless link or network cable and the management big cheeses can sit in their offices and watch how their factory is running.
I have done production control before, first using PCs which weren't rugged enough then PLC which were expensive and lacked the power. I have done this type of system twice with Parallax products and both systems are still working. The trouble with all my previous systems and all those I have studied is that none help the foreman to manage his machines better.
The photo doesn't do the light column Justice, the colours are amazing!!!
This project uses a (Very good) Parallax legacy controller. The controller is in the run-out phase so I'm not going to post schematics, software etc (if anyone want's it, they are welcome but I think it may be better to use the current stuff). The idea would work well with either Stamps or Propellers.
As usual, the reason I am here is I had a technical query, nothing to do with the controller, and the forum response was almost instantaneous. This is a very important aspect of Parallax products. The time and frustration you save is worth gold. I then saw a concern over how we never post our projects - fair criticism...
879 x 1200 - 126K
Comments
-Phil
Thanks,
-Phil
- For other members, Just look at the "boat fitting top" view and note the heat-sink, just visible under the LED.
- I've also attached the Datasheet. It's a Chinese "No Name" brand.
The heavy "spun plastic" white cover disperses the light very well (even down right to the edge of the base - a bit like light guides). On the other fillings I tried, you tended to get a greeny, red, blue kind of colour because the LEDs aren't central to the component base but this lense deals with that. (sounds confusing but I don't know how else to explain it, the colours aren't properly mixed by the LED lens on its own.)
Nice, practical project.
Reminds me of working at a noisy tissue converting plant and trying to figure out which machine siren was going off. We ended up with a very similar system to help the maintenance guys.
Cheers,
We say out here in Southern Africa ... and praise from St Christopher is praise indeed. I gather he was the patron saint of something or other.
Getting a kind word from Tom Sisk makes me feel fantastic. Tom, as you and I both know, its a very simple circuit, simple software. Many High school kids could build it.
The frightening part is the device will probably pay for itself in a couple of days. Businessmen world wide measure the effectiveness of a system using ROI. A good project has an ROI of perhaps 70%. This has an ROI well over 400%!!! MONEY FOR JAM AND YOU DONT EVEN HAVE TO BOTTLE THE JAM.
This is the power of the stamp and the other toys that Parallax sells.
Take care and happy stamping----
MikeK, you're giving your age away! Tape drives (...or do you mean the tape drives used in the textile industry?)
...but building on your idea, the technicians at our local water works "forget" to reset pumps that trip at night and our town then runs out of water. There is a little dark grey guy who wanders round here at night (3Ft 6" high I am told, dark blue hair too). He has a pointed head and long fingers and catches those that stray in the night. This gnome like chap bewitches people and they die (YES - They die!!! - it is a recognized form of bi-polar depression, our local hospital see dozens a year). Only light or sunrise can save you, If he manages top drag you off in the dark, you'll return in the morning, but to a doomed existence. Tokoloshi is bad, real bad, worse than the gutter monsters!
Now with a bunch of lights like this on the technician's desk and some bright spot-lamps on the offending motor, he won't have to face this naughty little chap...
Isn't technology amazing...
Isn't Africa wonderful...
I wonder what sort of heady mix we'll get by combining them.
BOOM!!!:smhair:
Thanks for the Tokoloshi story. My son is interested in cryptids & mythical creatures.
Using an RGB led for the light column is a great idea!
How do you collect the data for the machine status - sensors, operator panel?
Inputs - The idea is to make it as transparent to the machine as possible. Where spare inputs are available, we use them. In some cases the information is collected by the operator pressing a button. In some cases we use some pretty weird stuff
- PIR Detector to see if the operator is at his machine
- Current clamp on those expensive German machines where Herr Teknition doesn't want to give us an input
- Hall Effect sensor with comparator on those electric motors we can't get access to.
- An array of micro switches etc
It get's very expensive if I blow a circuit on a German machine and we have to fly in a technician (to replace a fuse!!!). We just don't have the skills here to do really simple stuff.
Below are some of the more fun stuff...
http://www.parallax.com/Store/Accessories/CommunicationRF/tabid/161/ProductID/710/List/0/Default.aspx?SortField=ProductName,ProductName
Use that to monitor the machines and send that info over the network to a computer that could display the status of all machines on one display.
-dan
I hadn't seen this, very interesting - AND it comes from Parallax!
There are many similar devices available, my latest South African electronics weekly magazine lists no fewer than 5. Most are proprietary, meaning they are designed to work with Siemens, or Allen Bradley or Omron. Over the years, I've built two myself, using a Stamp and later an SX. (Using a Stamp, you can adapt them to work with any control system)
The problem in the 3rd world isn't getting the information onto the PC but getting the machine to run ON THE SHOP FLOOR. SCADA (computerised production control) hasn't lived up to my high expectations of ten years ago. Improvements seldom cover the cost of the software.
It takes a shift, sometimes even a day to find out your production line stood yesterday because the mechanic never got there to fix it or you had run out of nuts, available from the local hardware store, 5 minutes away!
Generally, our profit margins, unlike western economies, are too slim to absorb a lost shift.
Japan, when they were a third world country in the 1950's stole an idea from Ford where lights on the production line showed the status of that line. The Japanese called it Andon (lanterns in remembrance of the dead). Andon is used extensively in the automotive manufacturing industry. These systems have been hijacked by us technological geeks and are now just an unimportant part of the SCADA system. They seldom tell the production supervisor why his line is standing or that this stoppage needs to be fixed NOW or the production manager will be visiting him in the morning.
Mine is just a VERY simple but VERY POWERFUL way to show everyone what the current status of machine are - at this very moment.
On the dark continent (Africa), we need simple solutions. If it was good enough to help Ford cope with production pressures during World War 2, it's good enough for us.
Thanks again
John