PINNED - Roboteq Controller - developing for powerchairs

Power wheelchair board for REAL info!

POWERCHAIR MENU! www.wheelchairdriver.com/powerchair-stuff.htm

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby LROBBINS » 04 Jan 2023, 13:55

Hi Snaker,

I did see your PM and will send you all the files - as soon as I get on top of the combination of things broken, bureaucratic hassles, and a terrible backlog of correspondence. Please be patient. In the meantime I'll answer one of your questions. For brushed motors, the HDC24x0 remains the best choice, but the 2450 has been upgraded to 2460 with a higher max voltage and some fairly substantial internal changes. While waiting for the stuff from me, do download the Roboteq manual and read the installation instructions with great care; there's important safety information there.

Ciao,
Lenny
LROBBINS
 
Posts: 5543
Joined: 27 Aug 2010, 09:36
Location: Siena, Italy

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby snaker » 09 Jan 2023, 10:03

I see several versions of a manual:
Roboteq Controllers User Manual (v2.1, v2.1a, 3.0)
MicroBasic Scripting Manual (v2.1, v2.1a)
CAN Networking Manual (v2.1, v2.1a)

Which ones should I use? Is the highest version the better?
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby LROBBINS » 09 Jan 2023, 22:44

I suspect that the important installation and safety parts are the same in all of the user manuals. I have version 2.1 and have not yet looked at 3, but that's probably the one you should download. The basic scripting manual will probably be useful later on, the CAN manual almost surely not at all, at least if you end up with something like my system which uses basic CAN protocols yet does much more wheelchair-specific stuff than would be possible with Roboteq's implementation. For now, what you should be working on is understanding the hardware installation requirements.
LROBBINS
 
Posts: 5543
Joined: 27 Aug 2010, 09:36
Location: Siena, Italy

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby snaker » 13 Jan 2023, 10:12

@lenny: Could you send me the latest script?
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby snaker » 26 Jan 2023, 10:07

I have read all 117 pages and roboteq manuals. I figured out the way to build a 48v powerchair and also components needed. Before diving into more detail and starting the build, I need some info:
1. I intend to build a powerchair that uses hdc2460 and 4-pole 6mph motors and 16s lifepo4 pack (I hope 16x120Ah). I estimate the max speed will be about 14mph. Is my calculation right?
2. The pack voltage will be 57.6v (16x3.60) when full charged. Does hdc2460 support that voltage? I ask this because while the name hdc2460 means supporting 60v but its datasheet says max VMot is only 50v (see the image underneath). I do not know if it is a typo fault in datasheet?
3. Is possible to completely stop the caster shake at the high speed (14mph)? Because if the caster shake problem remains, my main purpose of a fast powerchair will become meaningless.
Attachments
vmot.png
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby Burgerman » 26 Jan 2023, 14:57

I did 13S for 45V which gives more than double the speed of the 22v from a mobility controller. And probably will not damage motors so easily. That gave me 15 to 16mph (24kph) with 8.5mph motors. Torque not a problem with 150A. And it was very hard to stop caster shake. But I did. But its too much speed. Vehicle is too short... 10 to 12mph max makes more sense. 15 or 16 mph feels way faster!
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby Burgerman » 26 Jan 2023, 15:02

Turn sound up. Sounds like a motorcycle at 13S and this isnt full speed.
https://www.wheelchairdriver.com/BM3-co ... g-test.mp4

Caster shake before I lowered REAR tyre pressures. This is 12 to 14mph, uphill. Downhill = no shake!
https://www.wheelchairdriver.com/BM3-co ... -shake.mp4

This is 15mph, thats 23kph.
https://www.wheelchairdriver.com/BM3-co ... /15mph.mp4
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby LROBBINS » 26 Jan 2023, 19:42

57.6 V is too high, and would be too close to the limit even if the HDC2460 had a 60 V motor limit.

Caster shake is something aircraft designers have been fighting since at least the 30's when nose-gear layouts started to replace tail wheels. There is no analytic solution for this and designers have sometimes had to go to extremes to get rid of, or at least control it: many airplanes have hydraulic shimmy dampers (can't use that for a caster that has to go full way round), Grumman light planes have the caster stem running in a large fiber-filled cylinder saturated with a silicone grease, at least one British fighter used a nose wheel that had tread on both sides and a channel down the middle - scrubbing of those outside treads provided extra friction if shimmy started. It usually can be licked, but can take a lot of experimenting with air pressure, tread design, bearing pre-load etc. It can also be quite destructive if not controlled.
LROBBINS
 
Posts: 5543
Joined: 27 Aug 2010, 09:36
Location: Siena, Italy

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby snaker » 27 Jan 2023, 09:11

Thanks BM and Lenny. I have a more question. My current chair is 24V and uses 2-pole 14km/h motors. I used to run continuously in 9-10 hours without problem. Can I do the same with 48V, 4-pole motors? I mean if those 4-pole motors can operate continuously with 48V in 9-10 hours (supposing the battery pack has enough energy)?
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby Burgerman » 27 Jan 2023, 09:29

Its not about voltage. As long as the RPM does not cause them to fly apart internally then volts is irrelivant. I tested a set of AMT motors at 60V for 5 mins and they stayed cold, and didnt fly apart. So running on 45V max at full charge is safe. In fact the added air circulation internally helps cool the spinning part of the motor and brushes by transfering heat to the casing.

What causes damage is current. Which causes heat. Heat is caused then by load. The highest load is when turning, curb climbing etc but this is intermittent. And limited by whatever current the roboteq is set to.

If a motor was 100% efficient there would be no heat. So all sounds safe?

BUT when you climb a hill, load increases markedly. For long periods. Allowing a motor to heat up. Now consider that doubling the voltage means the motor can and will take 4x the power in watts as you climb a hill at double the speed. Its current loading doubles. But the voltage also doubles. So now you have 4x the watts being wasted as heat due to the motor being less than 100% efficient.

So here is your danger. Speed + hills. That can burn your motors. So as long as you are aware of this, you should be OK. As long as you set speed to 6mph as you hill climb... So its as it was before as far as heat loading is concerned. Running at double the speed on level ground doesent seem to be a problem. At least at 45V. 13S. But it does mean more heat. But on level ground that is quite low amps still.

See woody GBs estimation on the bottom of this page:
It shows battery range, motor load, watts at various speeds etc. As you can see this is on level ground. THIS is where you continuous rated motor watts comes into play. This is where they are rated for and safe continuous usage.
This is for my 13S battery and 8.5mph motors.
Attachments
range.gif
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby ex-Gooserider » 31 Jan 2023, 02:20

Might not hurt to put temp sensors on the motors and a way to monitor them... (I could be wrong, but I think the Lenny control hardware would have the bandwidth to manage adding a readout or at least a warning flag to the display?) I know that there is an Arduino library for working with Dallas One Wire sensors, as well as ones for thermocouples of different sorts...

ex-Gooserider
T-5, ASIA-B
Jazzy 1100
Jazzy Select 6
Quickie Q-7
Invacare Mariner
Want to make / get a better chair, ideally one that stands.
User avatar
ex-Gooserider
 
Posts: 5962
Joined: 15 Feb 2011, 06:17
Location: Billerica, MA. USA

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby snaker » 10 Mar 2023, 08:48

The HDC2460 is just restocked after long time out stock. I am going to order one for experimenting. Does the power module already include a programming usb cable? Do I need to add any accessory below into the cart?
2023-03-10_14-35-01.png
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby Burgerman » 10 Mar 2023, 10:54

Dsub is all custom, so DIY. USB cable (long) is useful, RC interface you can DIY or buy ready done. You will need it at least initially.
Dont know about the rest...
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby LROBBINS » 10 Mar 2023, 11:20

To protect your PC it would be a good idea to have isolators for either USB or RS232, whichever you use for downloading scripts. At one time the HDC could not use CAN and USB simultaneously, so download had to be by RS232. Newer production may not have this restriction. There may be cheaper sources for the isolators, however.
LROBBINS
 
Posts: 5543
Joined: 27 Aug 2010, 09:36
Location: Siena, Italy

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby snaker » 11 Mar 2023, 09:21

So I will need a HDC2460 + rs232 isolator + rs232-usb cable (buy later)?

In VN, I see some shops selling rs232 isolator called "DTECH RS232" for very cheap price, about $5. Is it Ok?
https://shopee.vn/Thi%E1%BA%BFt-b%E1%BB ... e39efc1342

Image
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby snaker » 11 Mar 2023, 10:19

And this usb isolator ADUM3160 costs only $6.

Image
Image
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby LROBBINS » 11 Mar 2023, 10:29

The purpose of an isolator is simple: keep a short circuit in the Roboteq from frying the port in the PC. Any, even cheap ones, should be suitable. I suggest wiring your own DB connectors for the Roboteq rather than a dedicated Roboteq connector so you have all the pins available for CAN, I/O etc. to use as needed.
LROBBINS
 
Posts: 5543
Joined: 27 Aug 2010, 09:36
Location: Siena, Italy

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby snaker » 22 Mar 2023, 02:15

I am gathering needed components. The first thing is an emergency relay. I only find this TE connectivity relay. It supports 900V/500A, coil voltage = 9-36V/0.2A. It costs about $35. Does it suit HDC2460?

Image
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby Burgerman » 22 Mar 2023, 06:14

Does it stay on or off when power is removed?
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby snaker » 22 Mar 2023, 09:11

I think it's in the link below. The datasheet says NO. So is it unsuitable? Will I need a NC relay?
https://uk.rs-online.com/web/p/contacto ... DwId1AMEtQ

I am confused between a relay vs a contactor. What's the difference between them?
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby Burgerman » 22 Mar 2023, 11:25

You can see a lot of details inc the contactor I used here.
https://www.wheelchairdriver.com/BM3-co ... CTRICS.jpg PART wired.
https://www.wheelchairdriver.com/BM3-co ... E_4069.JPG Also shows motor current sensors. You can do it without. But control is rough. I found that it was essential.

You will need to make this too from an old joystick shell. All intrnals are replaced and a 12 core cable used. Its all just switches (momentary and latched), resistors, led's, and a 4.5v swing apem joystick. https://www.wheelchairdriver.com/BM3-co ... e-made.jpg

Might help to carefully look at most of these pics etc.
Script is out of date.

https://www.wheelchairdriver.com/BM3-construction/
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby LROBBINS » 23 Mar 2023, 04:32

That relay is overkill. Burgerman uses a latching relay - pulse to on/pulse to off. I am using a TE V23132-B2002 non-latching relay on/off controlled by the script. The script only switches the relay state when virtually no current is flowing to prolong the life of the contacts (this way of doing things was approved by TE application engineering). It also serves as the emergency contactor because the 24 volts to the control traces of the circuit board is connected to a simple toggle switch at the joystick.

Both relays and contactors use a coil to pull in an armature to close or open the contacts. What are sold as "contactors" usually have solenoids rather than simple coils and many can interrupt very high currents without being damaged. However, they usually have a shorter life cycle - fewer operations before failure - than ones sold as "relays". The TE Burgerman and I have used are sort of in between - high current capacity (but not as high a breaking current rating as a contactor) and a relatively long cycle life if treated as described in the data sheet. Very high current capacity isn't really needed and even these TE relays are oversized. Except in an emergency it will not be switched when much current is flowing, and even in an emergency the current will be high only if it happens during a turn in place or starting out on a steep hill. To site a commercial example, the Dynamic DX90 power module uses just a single 40 Amp automotive relay even though it is rated as a 90 Amp power module.
LROBBINS
 
Posts: 5543
Joined: 27 Aug 2010, 09:36
Location: Siena, Italy

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby snaker » 01 Apr 2023, 10:33

I am still stuck in the emergency relay. I do not understand why BM and others prefer using a latching relay instead of a non-latching NC relay.

Firstable, I quote the description of the SW2 in the roboteq manual as below. Please notice the bold text. Does roboteq recommend using a NC relay? Because a NC relay works exactly what they say "closed at all times and open only in case of an emergency". A latching relay can work too but its behavior is not as exact as the description. In VN I found some latching AC relays but here they are called "alternating relay". Because they are mainly used to alternate 2 or more devices. E.g a plumping system uses a latching relay to switch between 2 pumps. If pump 1 is switched ON, pump 2 is switched OFF automatically and vice versa. Latching relays are not used for emergency cases.
The battery must be connected in permanence to the controller’s Red wire(s) or VMot terminal via a high-power emergency switch SW2 as an additional safety measure. Partially discharged batteries may not blow the fuse, while still having enough power left to cause a fire. Leave the switch SW2 closed at all times and open only in case of an emergency. Use the main On/Off switch SW1 for normal operation. This will prolong the life of SW2, which is subject to arcing when opening under high current with the consequent danger of contact welding.

Following the description, I drew a wiring diagram as below (I temporarily ignore the fuse and the precharge resistor to simplify the diagram). Please help me to check if the wiring is correct? This diagram can be used for a latching relay too. Just replace the toggle switch by a momentary switch.
EmergencyRelay_New.jpg
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby Burgerman » 01 Apr 2023, 11:15

When the robotec senses a shorted mosfet it sends a signal to disconnect the power. And that cuts off the roboteq too. And so its FAILED signal goes away. And on a normally closed relay that means it then gets power all ovr again. You want no power to the roboteq until you turn it back on with a button. As it should be.

Also, you want the contactor to not suck up your battery power all day long. So you have an on and off button too. That way its takes no energy when parked up, or in use all day long. But it can still turn itself off via the mosfet failed pin. Without it just turning back on again.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby snaker » 02 Apr 2023, 09:02

I thought the safety pin DIN14 is kept ON until the roboteq is restarted and the problem has gone. I missed at this point. So, the pin is only switched ON in an unknown time and then OFF. We will need a latching relay to cut off the power, a NC relay will not work.

BM, do you remember the part number of your relay? And I have some more questions:
1. When the relay is ON, does it consume power? If so, how much is its consuming power?
2. When the relay is OFF, does it consume power? If so, how much is its consuming power?
3. Is your relay wiring is similar as my picture above (just replace the red toggle switch by a momentary one)?
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby Burgerman » 02 Apr 2023, 09:18

BM, do you remember the part number of your relay? And I have some more questions:
1. When the relay is ON, does it consume power? If so, how much is its consuming power?

None. Its just a sliding switch. So it takes a short pulse of power to operate in either direction. Then nothing. In on or off positions
.
2. When the relay is OFF, does it consume power? If so, how much is its consuming power?

Non.

3. Is your relay wiring is similar as my picture above (just replace the red toggle switch by a momentary one)?

Not sure I follow your wiring.
On my system, there is a 12V 10A capable supply inverter, which pulls just 6mA at idle that is always powered. This has its own 5A fuse connected to its input. It is always supplied with power unless I pull out an anderson loop to totally disconnect battery. Which is only needed on long term storage.
This powers the 12V brakes on the motors via an SSR, and the MOSfet fail trigger on the roboteq is also connected to this 12V via another SSR. The relay powers the roboteq. The roboteq on/off as well as relay on off are by latched an momentary buttons on the joystick. So I can turn the roboteq off. Or the complete power off. Or the RC reciever on/off.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby snaker » 16 Apr 2023, 09:50

I finally found a suitable latching relay for emergency and tested it Ok. It's probably a clone or fake of TE relay V23130-C2021-A412 but it works, I just do not know how long it will last :cussing

Now I move to next step: the fuse and the precharge resistor.
1. What amps rating should I use for the fuse?
2. Should I put a diode in series with the precharge resistor? If so, what diode should I use? I ask this because in the manual roboteq strongly recommends using a diode when connecting an inductive load to a DOUT pin (see the first image below). But I do not see BM used a diode. And in a diagram, roboteq does use a diode but it's put at the fuse, not at the relay (see the second image below). That confuses me :cussing

diagram2.png

diagram1.png
User avatar
snaker
 
Posts: 1193
Joined: 23 May 2015, 10:45
Location: Vietnam

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby Burgerman » 16 Apr 2023, 10:56

I used bi directional TVS diodes.
And I didnt allow the roboteq to control the relay OR the brakes directly. I used a pair of eBay SSRs DC to DC instead to take the load. The 12V inverter feeds these SSRs directly.

What size fuse? The roboteq can provide 150A x2 to the motors. So on the face of it that means 300A. But that wont happen because you areusing a high input voltage and so a 150A fuse is already overkill.
You also want a diode across the relay. So as to allow regeneration power to stll reach the battery if that relay trips or is turned off with motors running. Or the regen spike has nowhere to go and the spike will kill the roboteq.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby Burgerman » 16 Apr 2023, 10:58

The futher you get into this the more involved it gets...
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: PINNED - Roboteq Controller - developing for powerchairs

Postby Vitolds » 16 Apr 2023, 13:42

Hello. read this AN70614 https://www.roboteq.com/support/documentation-download
This file has more explanation on how to turn off the controller.
Vitolds
 
Posts: 531
Joined: 26 Mar 2014, 22:12
Location: Moscow Russia

PreviousNext

Return to Everything Powerchair

Who is online

Users browsing this forum: LROBBINS and 65 guests

 

  eXTReMe Tracker