About the wheelchair motor reuse project

[laoshanren]

I have to pick up the project that has been on hold for a long time.

It is reusing the power wheel chair motors to drive a track with 433MHz RC controlled (picture ARDUINO RC).

Originally I planned to design a new connection manifold and set of H Bridge and get rid of the control modules from the chair (see picture MANIFOLD) , thanks Wood sent me lot of ideas on Bluetooth control.

There are two EBAY drivers have been burned after real motors test (see picture DRIVER).

I need help on few questions.
1. How can I separate the H Bridge from the chair’s power module (picture MODULE) and reuse it?
2. There is lot of functions on the module’s build in say tilt, I only need to control the motor speed and direction, how can I disable the surplus functions? I have the PC connection to the chair.
3. Measured the motor coil just has 0.8 Ω, what is the roughly wattage?
Thanks

[Burgerman]

Motor wattage?

A stalled or heavily loaded typical powerchair motor would draw 200 to 350A typically.
It never does, because the powerchair motors controller is current limited in software to between 80 to 120A in most chairs. Why is the motor low impedance? Because it improves control and torque at higher speeds than stall or low speed. And because it LOWERS the battery Amp load. If it is limited to just 100A by the controller, and thats at say 1/3rd of the pulsewidth (33% duty cycle) then the battery current is only 33.3A.

A simple H bridge wont work. Even if you have the steer mixing and everything correct. You also require complexities such as lowered turn rates, lowered reverse speeds, and motor load compensation is essential, as well as turn acceleration, and deceleration rates all independently of forward and reverse settings. And it gets complicated fast.

Motor WATTS tell you almost nothing useful.

Typical powerchair motor without current limiting is rated at 250 to 450Watts.
But in use it takes rather a lot more!
Without current limiting in the controller, it will easily draw 300A at stall or heavy load, and 24V so thats would be 7,200 watts approx. Which will burn it out in a few seconds. If limited to say 100A which is typical, thats 100 x 24V or 2400 watts per motor. This happens every time you climb a curb or a ramp, or accelerate hard from 0mph.

Your simple H bridge controllers stood zero chance of working. You not only need the ones in the powerchair controller but its very complex control algorythm, and it will be essential to program this to suit you application as well.

[Burgerman]

Also motor impedance. (resistance). For a 2 pole motor is typically 70 to 120MOhm. For a crappy one. 4 pole motors are usually 40 to 45mOhm. So basically your little H bridge will go into orbit without proper software and current limiting, and low acceleration levels. And its too small anyway.

[laoshanren]

Thank you Burgerman.
If the motor start current limitation can be done by software, can I done it by the Arduino sketch? also I can buy another H Bridge of 100A.
BTW, when I did testing hook up just 12V, the two motors running very well, the drivers burned by 24V.
I tested the driver by a little cycle at ~31KHz PWM.
How do you think this 100A driver, can be better?
https://www.ebay.com/itm/100-A-High-Pow ... :rk:1:pf:0

[Burgerman]

A free running motor at constant speed only takes 5A.
A loaded or stalled motor will draw 300A or maybe more... Transistor. Fastest fuse on 3 legs.

Does your H bridge have a current sensor, and can the H bridge limit the current to 100A or less? If not it will fry!

On top of this, you WILL need a script or software similar to this to make it usable.

http://www.wheelchairdriver.com/BM3-con ... Script.txt

Or it simply wont work or steer properly...
Inside that chair controller is something similar, but way more complex.

How do you think this 100A driver, can be better?
https://www.ebay.com/itm/100-A-High-Pow ... :rk:1:pf:0

No. On its own without all the software and current limiting and something like that script it will die fast and wont work properly anyway.

[laoshanren]

I didn't find the driver can limit the current. I was think that was burned by 'shoot through' .
is it OK to use sketch limit the current and use a 100A driver?

I'll take a look of the current limit page.

Another solution is to use the chair's control module, is it possible to directly input control signal to the 6 pins JACK like below?

[Burgerman]

What is sketch limit???

You must have a current sensor.
A low acceleration or slow speed start will not help. Nor will it work because you will not have adequate starting current for a turn etc.

Have a slow careful look at that script. Its required, as is a current sensor. Its not as simple as you think.

You already have a chairs controller and should think about usig it. Because it already does all the stuff you have yet to understand. About 3 years worth of work and thinking and development time...

[Burgerman]

You want it to be able to do this and be controllable right?
Then quite apart from current limiting. This REQUIRES
1. 2 current sensors
2. that complex script. (3 years of lennys work!)
3. motor compensation

Its not possible any other way. Skid steer and proper control is not simple!!! You may THINK it is. But you have not found all the problems yet!

http://www.wheelchairdriver.com/gopro/bot.mp4

And you HAVE all this in that wheelchair controller.

[laoshanren]

When I say sketch limit means use ARDUINO's software to do the current limitation, sorry my English.

The reason I try to use gamepad joystick to do the control, is I need many buttons to do many actions, and the chair's joystick don't have that. If I can use my gamepad control directly link to the power module, it will be perfect.

[Burgerman]

Its way more complex than you have figured out so far. Does the arduino "sketch" use current sensors? How does it measure motor Amps?

I added more above take a look.

[Burgerman]

Also you can either inject a DC signal via a joystick, or interface via the bus, but not simple viewtopic.php?f=2&t=4867&start=570

[laoshanren]

Oh, a wonderful bot.
it's what I gonna to do see picture.
1. do you know what current sensor used in the control module?
2. can I disable the spare functions on the module?

[laoshanren]

[quote="Burgerman"]You want it to be able to do this and be controllable right?
Then quite apart from current limiting. This REQUIRES
1. 2 current sensors
2. that complex script. (3 years of lennys work!)
3. motor compensation

Is the current sensor like the ring in the picture?

[laoshanren]

Yes, the power module used the current sensor like this:

[woodygb]

https://drive.google.com/file/d/1BAIMF7 ... DfA-k/view

[laoshanren]

https://drive.google.com/file/d/1BAIMF7_iGYuHWxAfVyFmNA94pGMDfA-k/view

Thank you Wood, it is a great job.

When I planed to use wireless RC control cause of few reason:
1. I need many buttons to fulfill many actions in the future;
2. Is the wireless more reliable and longer control distance?
3. It is easy to get and modified because my friend has been doing RC for toys long time.

I almost done the test by my connection manifold that totally get rid of the chair modules, I pick up the modules now after burned two motor drivers bought from EBAY, I guess the chair modules be able to handle larger current, it used 16 pcs P150NF-55 N-channel 55V on their H Bridge.

But Burgerman told me that's not that simply as I figure out so far.

Is it possible to input control signal directly through the 6 pin JACK? is this JACK same as Burgerman mentioned 'BUS' ?

[woodygb]

Use the wheelchair controller.... it's very easy IF the joystick is an analogue type.

I have previously asked you for a picture inside your pod of your joystick...but it was not clear.

I have made R/C and Bluetooth using much the same Arduino hardware arrangement.


Fairly simple connection inside the pod from the Arduino interface .. just 4 wires and the interface plugged between the joystick and the pods board ribbon.

ON/OFF ( Black and White ) Positive 24v & GND.

IF your joystick is the same as shown below.

[laoshanren]

[quote="woodygb"]Use the wheelchair controller.... it's very easy IF the joystick is an analogue type.

I have previously asked you for a picture inside your pod of your joystick...but it was not clear.

I have made R/C and Bluetooth using much the same Arduino hardware arrangement.

Thank you Wood,

Yes, my friend said same, it is easy to replace the joystick signals and use the original sets.

My project need fulfill much many functions, and I need to add 6 more buttons beside the gamepad's 4, like my picture 'ARDUINO RC' shown, the only thing I need from the chair module is the H Bridge, if its easier than to build a new heavy duty one.

[woodygb]

ALL the extra functions that you require can be via R/C switches ...

E.G. This 2 way R/C switch uses just 1 channel.

https://www.ebay.co.uk/itm/Radio-Contro ... 3423150872

STOP mucking around with trying to build H bridges!

This one is Radio controlled.... uses 2 channels for driving .

https://www.dropbox.com/s/ql42k38v3jiew ... 9.MOV?dl=0

[Burgerman]

Its NOT easier because theres a reason that the powerchair controllers have current sensing, motor load compensation, and 101 control settings and a lot of computer code developed over many years. It is what makes them drivable!!!

Your tank steer device may only require 5A to go forwards. (5% pulsewidth. And will need at least 50 to 100 Amps to turn in place. The motor compensation means that you get all those amps ONLY WHEN REQUIRED to turn slowly with a small joystick movement. Remember that you wont want max power (volts) to turn at a safe controlled speed, just maybe 15%. But a 15% pulsewidth will not turn the thing at all. It wont draw adequate Amps. So full left stick? Nothing happens... Thats why you need motor load compensation for e.g. Only 1 of the many issues that you have yet to discover. Ever wondered why the robots on robot wars are barely controllable and can spin on the spot like a propellor? Its because they lack the things I am talking about. The chairs controller has that stuff built in. Its essential for proper control. Not to mention that script. Did you take a look? Thats whats needed for proper tank steer control without randomely zooming about while the robot more or less ends up wherever it wants like on TV...

The H bridge is about 5% of the controller. Its the easy bit. But you need the rest.

http://www.wheelchairdriver.com/gopro/rc.mp4
http://www.wheelchairdriver.com/gopro/RC-BM3.mp4
http://www.wheelchairdriver.com/gopro/rc2.mp4

[woodygb]

Take our word for it!...

[laoshanren]

ALL the extra functions that you require can be via R/C switches ...

E.G. This 2 way R/C switch uses just 1 channel.

https://www.ebay.co.uk/itm/Radio-Contro ... 3423150872

STOP mucking around with trying to build H bridges!

This one is Radio controlled.... uses 2 channels for driving .

https://www.dropbox.com/s/ql42k38v3jiew ... 9.MOV?dl=0

Thank you Wood,
The attached picture shown my receiver side, I used 14 relays + 2 on pcb relays to do my actions.
Sorry about the mess.

[laoshanren]

Its NOT easier because theres a reason that the powerchair controllers have current sensing, motor load compensation, and 101 control settings and a lot of computer code developed over many years. It is what makes them drivable!!!

Your tank steer device may only require 5A to go forwards. (5% pulsewidth. And will need at least 50 to 100 Amps to turn in place. The motor compensation means that you get all those amps ONLY WHEN REQUIRED to turn slowly with a small joystick movement. Remember that you wont want max power (volts) to turn at a safe controlled speed, just maybe 15%. But a 15% pulsewidth will not turn the thing at all. It wont draw adequate Amps. So full left stick? Nothing happens... Thats why you need motor load compensation for e.g. Only 1 of the many issues that you have yet to discover. Ever wondered why the robots on robot wars are barely controllable and can spin on the spot like a propellor? Its because they lack the things I am talking about. The chairs controller has that stuff built in. Its essential for proper control. Not to mention that script. Did you take a look? Thats whats needed for proper tank steer control without randomely zooming about while the robot more or less ends up wherever it wants like on TV...

The H bridge is about 5% of the controller. Its the easy bit. But you need the rest.

http://www.wheelchairdriver.com/gopro/rc.mp4
http://www.wheelchairdriver.com/gopro/RC-BM3.mp4
http://www.wheelchairdriver.com/gopro/rc2.mp4

Thank you Burgerman,

You are right, the wheelchair is really a quality stuff.
any clue how the function of the interface of infineon saf-c167cr-lm is? is it take the PWM signal and push out to Bridge?

[laoshanren]

when I try to communicate from PC to Q6, got error message as below, nothing changed. what can be?

[woodygb]

You should supply the details like this ...

I am using a software program X on my P.C. to try and communicate with Q6 logic controller ( part number ) using USB interface type Y ( plugged into the pods charging port ? ) with settings Z.

I guess that your using Curtis 1314 programming software ?

[laoshanren]

You should supply the details like this ...

I am using a software program X on my P.C. to try and communicate with Q6 logic controller ( part number ) using USB interface type Y ( plugged into the pods charging port ? ) with settings Z.

I guess that your using Curtis 1314 programming software ?

Thank wood,
I'm using 1314 - 4402 try to modify the Q6 power module, the communication is OK, just don't know which function should be disable now.

Also, do you know what sensors these two round white are? how to disable them?

[woodygb]

Ha! ....I can see your confusion ....they are I believe plastic covers over the mono jack plugs.... not sensors.


e.g.



BTW ...My name is Woody .

[laoshanren]

Ha! ....I can see your confusion ....they are I believe plastic covers over the mono jack plugs.... not sensors.


e.g.



BTW ...My name is Woody .

Thank you Woody, sorry about.

I took one out, see the picture, the chair I have is much more fancy than others I saw. It give out any error in any time.

[woodygb]

Q-Logic Hand Control
The hand control is mounted to the controller bracket with four bolts. A programmer/charger port is located on the
underside of the module, as are two covered parallel jack for remote mode and on/off switches.

https://www.pridemobility.com/pdf/owner ... ic_boi.pdf

Have you a number for the pod ?

http://javafoundry.com/home/Q-Logic_Tec ... Manual.pdf

[laoshanren]

Q-Logic Hand Control
The hand control is mounted to the controller bracket with four bolts. A programmer/charger port is located on the
underside of the module, as are two covered parallel jack for remote mode and on/off switches.

https://www.pridemobility.com/pdf/owner ... ic_boi.pdf

Have you a number for the pod ?

http://javafoundry.com/home/Q-Logic_Tec ... Manual.pdf

Yes, the pad is : CTLDC 1467