K8055 - Dual Wiper Motor Control with Variable Speed

Another HUGE leap forwards thanks to SirNoName!

Thank you so much to SirNoName for unlocking the mystery of how to get Profiler2 to recognise more than one K8055... :

in fact... how to get UP TO 4 k8055s, driving up to 8 wiper motors with full direction and speed control!!! (as you can probably tell, I am more than a little excited about this!!)

I was looking for a complicated solution, but the answer is so simple I can't believe I missed it:
It's another jumper issue with the K8055! - if anyone has never set jumpers before, let me know and I will post a short video...
For those who are familiar with jumpers, all you have to do is set the card address using jumpers SK5 and SK6
(you cant miss them... they are right in the middle next to the table printed on the pcb giving the settings for the card addresses : )

The following combinations of settings give up to 4 card addresses:
For address 0, Set SK5 to ON and SK6 to ON (This is the manufacturers default for the prebuilt board)
For address 1, Set SK5 to OFF and SK6 to ON
For address 2, Set SK5 to ON and SK6 to OFF
For address 3, Set SK5 to OFF and SK6 to OFF

The pictures below show what happened when I plugged in both of my K8055s set to 0, and then changed the jumper setting to 1 for the second board... (unplugging it first of course )

A quick click of the Start HW Rescan button, and as if by magic, the second set of inputs and outputs appeared!

There is no way I'm gonna sleep tonight now ... I have ordered another wiper motor, and fully intend to build another two actuators this weekend - for sure I am at least going to test controlling the two motors I have with the two different K8055s... then it is just a matter of connecting another motor through the other channel on one of the boards to achieve a 3dof sim build for less than £140 all in!

I LOVE THIS SITE!!! :thbup: :thbup: :thbup:

Tim 8)

Re: Connecting Position Indicating Pots to K8055...

Hi
i see you talk about PId, i mvery interesting to understand and see your setting!
i use the same configuration hard and i 'm not use the PId, how make the setting, can you show me the PId in XSIM setting with a sceen or a video? ( dynamic speed with the PId setting)

thank you for your help

Hi bigtalltim,
Hi riton,

Same question as riton, I would be really interested in a good setup using dynamic function.
As you already know, I've managed to connect the K8055 to the Sabertooth 2 x 10A (the diagram is simple), and the configuration should be normally easy in X-sim. But, I can't understand why it doesn't work. I'm not able to do like you with the tablet-test on your video. My platform doesn't keep the position compared to the consign, Why ? (I'm using a linear pot of 10k).

Many many thanks in advance for your explanations Bigtalltim

Regards

Well, theoretically. I guess you will struggle to run even 3 axis, as the performance demand for on-pc PID calculation is pretty huge.
Thanos AMC controller, in comparance, does those calculations, including pot read-out, in the Atmega mp. Without any antivirus programms or system tasks interferring continously.
I am quite curious how your K8055 setup will perform in the final stage.

Great actuator build btw :thbup:

Regards

PID (or Proportional-Integral-Derivative) control is a useful way of fine tuning a control loop.
In this case, the movement caused by driving the motor loops back through the feedback pot and provides a value. Profiler runs a series of calculations to decide whether the system has met the desired state. if not, the PID algorythm works out how far off the target the current state is, and makes a further adjustment to compensate until the desired state is reached.

Here is a link to a much better description of the overall concept than I could ever come up with...
...it has been far too many years since I studied control systems!

http://en.wikipedia.org/wiki/PID_controller

I particularly recommend that you look at the section on Manual Tuning about halfway down - effectively, this will show you how to use the Kp, Ki and Kd offsets in profiler to fine tune your system on the fly.

The dynamic output I use controls the PWM signal, and really the only adjustment I have needed to make so far is to adjust the signal using the Global Minimum Analogue Output option so that the motor moves straight away - I have a long way to go before fine tuning is realisically an issue! The video I posted has Kp, Ki and Kd set at 1 (the default settings)

Tim

THANKS

I'm nearly the good config I think. I've try something, and with I was lucky, I found almost the good setup, I think.
Now, I can reach the consign and the platform keep it. There is still a little yo-yo, but because of my poor quality platform. An other point not solved, the dynamic option doesn't seem to work very well. The motor moves but still at the same speed...not really what I expected.

THANKS AGAIN

Hi Adbgg

I am going to do some reading into the sabretooth boards to try to understand them better... in the mean time, try adjusting your sensitivity and speed trigger value - this screenshot below shows the setup I was using for the actuator in the last video... I had to turn the sensitivity right down to stop the platform being jumpy



One other thing - have you set to Move and hold, or Move and stop?
If move and stop, what does your stop routine say? mine just sets PWM to 100%... that may not be enough if you are able to turn your motors by hand or under the weight of the platform... I believe that move and hold will continually adjust the position rather than just getting there and turning off!... Move and Hold might work better for you...

Let me know if any of that helps... I'll see wht I can find from Sabretooth

Tim

I will test tomorrow...and I will keep you informed of course. Thanks again for your Help and your advice, I really appreciate.
Maybe, I will post some pictures of my setup in X-sim, to show what I did. It may help other members of this forum.
See you.

Hi Christian

You make a good point and it is one that I am keen to test later on today - I have been wondering myself about the ability of PC software to keep up with the AMC controller... with a fast PC, I am confident that the processing power will be suitable.
My reasoning is simply that the PC is way more powerful than the AMC board, and is specifically designed to cope with masses of multithreaded calculations simultaneously... The test will help to determine whether a second pc controlling the sim would be necessary in my setup to back up the PC running the game.

I am going to set up my test actuator again this evening as follows using 2 x K8055s to run the following tests:

In the first test, only one actuator will be used to allow comparison with the reactions in the last video.
The other channels will be set up as if they had acuators connected so that they are pushing the processing capacity of the PC with two boards to the max!

K8055_1. PWM Channel 1: TestTablet 21 driving Motor 1 in actuator with feedback from Pot 1 - this is the TestTab slider I will move.
K8055_1. PWM Channel 2: TestTablet 22 on fast sine wave. No motor connected, but PID algorythm receiving positioning feedback from Pot 1
K8055_2. PWM Channel 1: TestTablet 23 on fast sine wave. No motor connected, but PID algorythm receiving positioning feedback from Pot 1
K8055_2. PWM Channel 2: TestTablet 24 on fast sine wave. No motor connected, but PID algorythm receiving positioning feedback from Pot 1

As a second test, I will connect the other motor (in its own actuator if I can get it built today ) to Channel 1 on the second K8055.
This will test the processing power of the system, and also the ability of the system to effectively drive 2 K8055s.
In this test, both actuators will be driven by the same TestTable slider.

Each of the sine waves will be at a different postion before automation, and because the feedback relates to a different control loop, they will never achieve their target position... That means that the PID algorythm, for these channels will be constantly working flat out - should be a pretty intense test of system capacity!

Tim

PS. Thank you - I am very pleased with how the actuator turned out... particularly with the positional control working so well!

Please do! :thbup:

This thread is about how to use the K8055 as a controller for wiper motors - any hardware option or frame setup is very welcome!

It is all great stuff for anyone starting out on a budget or with limited electronics knowledge - the more options the better

It will also give anyone already using this solution a chance to compare and maybe upgrade or tune their own setup...

Tim :

thanks
i already use this config, with dynamic speed.
i not see a big difference with or without PID in my last test;
i finally put Off the PId setting.
but with your help and setting, i try again to find a setting.

it possible my old computer was not powerful enough
no i have a new special for the simulator.

i test again .

thank for your help

er...ok...maybe it will be sooner than I said that I will have my project started...lol. I ordered a K8055 (assembled), all the parts for three relay boards, a new Weller soldering station (bout time I replaced my old weller pencil iron), two 12v 57A server PSUs (in series for 24v 57A), and my three 24v wheel chair motors arrived yesterday! (I was lucky enough to find two for 45.00 in an auction and another matching motor for 29.00 in another auction). I prototyped an actuator today, based on yours (Tim) and the example that Frakk posted on page six. Perhaps I will have a short video later this week but I doubt it will add anything to the discussion. Thanks again for starting this thread, I believe it will become a bible of sorts for those wishing to use the K8055. I will order an additional K8055 after I have this one set up properly and working. I think I might order an unassembled unit, as I need to justify to my wife the cost of the Weller soldering station, lol.

Edit: I have a circuit board layout almost ready for my CNC table. I just need to have the relay socket in hand to make sure everything will fit properly. I did a test cut yesterday (In laminate coutertop material) and everything seemed to be perfect.

Good stuff! :thbup:

What components did you go for in the end? (I'm thinking diodes, resistors and relay for 24V)

Just make sure that you protect the input on the K8055 if you are using more voltage - I have posted a question on the Velleman forum to get their recommendation for resistance necessary to protect the inputs if increasing the voltage to 24V...

Tim

Honestly...I hadnt thought about that. I look forward to any response that you might get from their forums.

As to the components, the relays are 24v 12a DPDT with a DIN socket, the diodes are just standard fast recovery 100v units, and the resistors are 1k

Edit: I forgot to mention that the transistors are 100v/15A (max)

Hi Historiker

Apparently the inputs of the K8055 are rated for up to 50V @ 100mA...

What is the current draw of your relay coil?

I will happily look this detail up for you if you cant find it... theres bound to be a data sheet somewhere on the web!
Just post the model number of your relays and I'll dig it out for you

Tim

37ma but here is the entire spec sheet:

Specification Value
Coil Voltage (V) 24
Maximum Current Rating 12A
Coil Current 37mA
Coil Resistance 650Ohm
Contact Arrangement DPDT
DC Coil Voltage 24V
Family LB
Maximum Pick-Up Voltage 18VDC
Minimum Dropout Voltage 2.4VDC
Contact Material Silver Cadmium Oxide
Minimum Operating Temperature -40°C
Maximum Operating Temperature 60°C
Mounting Plug-In
Termination Style Quick Connect
Specification Value
Contact Form DPDT
Pin Count 8
Package Type Dust Cover
Product Depth 21.5mm
Product Height 35mm
Product Length 28mm
Product Type Electromechanical Relay
Type Power Relay
Relay Construction Non-Latching
Coil Resistance (ohms) 650
Maximum AC Voltage Rating 240V
Maximum DC Voltage Rating 30V

Good progress guys!

Historiker: If you connect the power supplies in series, you will have to isolate their grounds, otherwise they will short circuit and shut down the minute they are powered.

Frakk, correct. I will also have to isolate them from each other. In case there is a ground fault I will solder a small neon light to both cases (it will light up in case there is a short). I have researched them alot but thanks for the heads up anyway. I should have mentioned the dangers of using two or more server PSUs in this way.

Something here for anyone wanting to go beyond 12V.

The values of the relay coil I am using in my solution are as follows:
Nominal voltage: DC12V
Operating range (V): 9.6-13.2
Coil resistance: 160Ω±5%
Current at nominal voltage: 75mA

This is within tollerance, and ok...

If the current draw of your 24V relay coil goes beyond 100mA CliffyK (another velleman expert) offers the following:

Tim

Great information Tim!! Thanks!