Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control

[MPaulHolmes]

And just like that, regen is solved! haha

[thingstodo]

Originally Posted by e*clipse

BTW, I found one for you on E*bay:
AWD Rear Carrier Differential Engine 2008 Lexus RX400 with 76 500 Miles | eBay

The Lexus RX400 is mechanically the same as the Highlander Hybrid. This one looks a little rough; like it's been on salty roads a lot. You probably could find one in better condition...

If this would be good enough for Paul's testing .. that would be AWESOME! Anyone else want to split the cost/shipping?

If the unit is sealed, does the salt make a difference? Or is it not sealed?

[thingstodo]

Originally Posted by MPaulHolmes

Sure, if you use 1200v IGBTs, and 650v worth of batteries (or a boost converter on the front).

Hey, how should we do regen? In a perfect world, the throttle would be a wig wag, where you twist forward to command positive torque, twist backward to regen. But this is a crazy messed up world. So, what do we do instead? haha.

What component values change to adjust the boost you discussed earlier, with the battery + having an inductor in series to the controller?

[thingstodo]

Originally Posted by e*clipse

Another method ( My Honda Insight ) Two different inputs, on on the brake pedal, one on the throttle. The throttle is straight forward. The brake allows the regen to work in that "dead zone" where the pads haven't touched the rotors yet and aren't doing anything. I would still want my brakes to respond quickly, like a normal car, so I wouldn't suggest an extended "dead zone."

Good description of regen on the brake pedal

[e*clipse]

Is that pin accessable, even if it means soldering on some sort of auxilliary board?

The funny thing about the QEA, QEB and index pins is they all interchange for AtoD pins. Fortunately for my resolver requirements, I can probably just change out the code; the safetie circuitry Paul designed around them might just work for the resolver...

One option for regen might be a "rocker" gas pedal - it has a centering spring and can move mostly forward like a normal gas pedal, and rock backward or lift for regen. Controls like this were used on some industrial equipment. A neat thing about the RTY sensor I mentioned is the range of sensing angles: +/- 25 degrees to +/- 180 degrees. One sensor on a rocker throttle could work with one +/-25 degree sensor for brake and PART of the regen signal.

I think something like that pressure sensor Astro found would be great in combination with standard hydraulic brakes.

Originally Posted by MPaulHolmes

There is one more A/D. How would the brake be a variable signal? I've only heard of pressure switches, but not linear things, so more pressure gives a "more pressure" output. Are there 0-5v brake signal things? We would have to add a little RC filter, and connect to the unused A/D with a wire. Not a big deal.

The dang Index, QEA, QEB are hogging 3 of the A/Ds unfortunately. I had used a 40 pin thru hole dspic30f4011 because the tqfp or whatever they are called chips are hard for most people to solder.

I wonder if it would be mechanically possible for the brake to pull the throttle one way (regen territory), and the gas pedal to push it the other way.

EDIT: OK, I found a brake pressure switch. Basically a throttle. ground, 5v, and 0-5v as a function of PSI.
Brake Pressure Sensor (DSC/ABS/BRAKE Trifecta) - Bimmerfest - BMW Forums

[Astro]

Originally Posted by MPaulHolmes

And just like that, regen is solved! haha

I found the data sheet / product specifications.

It is a 5v supply.

Online-Katalog Sensoren

There is even an example circuit for interfacing it to a micro controllers ADC.

Seems to be quite a few sellers selling used ones on eBay.

[freebeard]

??? Buyer ???

I've got a line of credit at the last good VW shop in town, Rich's German Motorwerks. The 'buyer' is the son of the owner who works the front counter. I found out today that I was his first customer, about 30 years ago. In exchange he's getting the '61 VW panel van I've owned since 1978.

The instruction I left them with was pick one as good as the $650 one, at the $400 price.

I've worked in software development but I don't write code, so I'm trusting that you guys can deliver a suitable controller. I do have questions about the process. As it's an 'open' project, what licensing is it released under? Creative Commons?

Are you affiliated with any makers? For instance I searched on http://www.google.com/search?q=makerspace+Maricopa,+AZ and see there is a facility at ASU and at Maricopa High School.

As for regen, one of my driving postures is left hand on the wheel at six o'clock and right hand on the parking brake lever. Since I don't like a mushy brake pedal, but the parking brake has 6-7 clicks until it engages (max about 12 clicks) I would use that. And reverse the button so it's push to set. So basically three inputs.

[MPaulHolmes]

Dang it it's so much fun when a bunch of people are sharing ideas!

EDIT: I'm not aware of any license for anything. I'm just hanging out at home, making stuff up as I go. haha. Thankfully, I don't teach at Maricopa HS. I used to teach at a high school for one horrible year. I don't actually have much of any sort of plans for anything. I'm just trying to make an AC controller that people can adapt and change the code how they see fit for their own needs. I don't see the software as too bad. The boost stage addition stuff, I'm told (by the EVTech list), will work, but it does add a level of complexity.

For the boost stage, since the board that's on its way wasn't for driving 4 half bridges (only 3),you would just need one more dual igbt, and two isolated power supplies/drivers. Then, you just need a fixed "duty" and "1-duty" that would give you the right output voltage (+/-, ignoring sag). Maybe you could send 5v, ground, +24v, etc... over to that board. Then, maybe it could have a little 8 pin micro that does nothing but spits out that fixed duty and 1-duty. Maybe I could make a little driver & isolated supply board. It will already have an ATTiny25 micro on there acting as an oscillator for the isolated supply. Maybe it could optionally (using jumpers) also generate the 2 fixed duties. so it could be a standalone boost/isolated supply/driver board, or just an isolated supply/driver board if you leave off the jumper.

At the moment, I only have 600v 600amp IGBTs. If people were wanting to drive that 650v motor, you would also need a different ring cap, and 1200v IGBTs. They have an 800v ring cap now.

[Astro]

Originally Posted by freebeard

As for regen, one of my driving postures is left hand on the wheel at six o'clock and right hand on the parking brake lever. Since I don't like a mushy brake pedal, but the parking brake has 6-7 clicks until it engages (max about 12 clicks) I would use that. And reverse the button so it's push to set. So basically three inputs.

As soon as i read that i was visualising you pulling up to some traffic lights but instead of stopping you end up doing a big handbrake drift right through the intersection.

Adding the hydraulic pressure sensor to the brake line shouldn't give mushy brakes. Actually they should seem more responsive as the braking (regen) would engage at a higher pedal than normal. Also the brakes wouldn't suffer from brake fade like disk brakes do as they heat up.

[Astro]

Originally Posted by MPaulHolmes

... Maybe I could make a little driver & isolated supply board. It will already have an ATTiny25 micro on there acting as an oscillator for the A/D. Maybe it could optionally (using jumpers) also generate the 2 fixed duties. so it could be a standalone boost/isolated supply/driver board, or just an isolated supply/driver board if you leave off the jumper...

I don't think i will need the boost feature (motor has been rewound for a lower voltage) so the board that you have ordered will be sufficient for me.
If i boosted the voltage then i am sure i would end up grenading my motor from too high an RPM.
Do any of the other prototypers/beta testers need voltage boost? If not then developing the controller with 4 IGBT capability may be the way to go and save the 3 IGBT controller boards for people who don't need the voltage boost.