Lexus GS450H VCU Support Thread

[Jack Bauer]

Excellent work.

[xp677]

Also I need to add sensor to allow me to monitor amount of braking force requested as my car does not have brake pressure sensor.

I used a gear shifter from a Toyota Auris hybrid (2017+), it has an analog x/y output, and features a "B" straight-back position which springs back to the centre. I mapped this to a regen request, so I just pull back on the shifter for regen.

The issue with adding a brake pressure sensor is that the hydraulic brakes are actuated by the same pedal - you would need to convert to brake-by-wire for this to be effective, something I won't consider touching!

Alright, working regen has been demonstrated on the bench using the code posted in my github repo!

This looks great! Glad to see some more progress on this unit. We've come a long way with this unit over the last few years!



Next up, the two-speed transmission! I've posted about it before and listed the steps we would need to program in to have it function, but I'm still not in a position to try it for myself

[Bryson]

Perhaps I can help there. Do we have documentation for the solenoids and how to actuate them for each gear? The torque mapping shouldn’t be too difficult, just need to kill mg2 torque during the shifting window.

[xp677]

It should be covered in this document: https://www.osti.gov/servlets/purl/947393

This is the same transmission as the GD450h, except this has a transfer case attached, and uses a different inverter.

Check out page 47.

I believe the SP solenoid is controlled via PWM to adjust line pressure. SL1 and SL2 control the clutches within the ravigneaux gearset. PB1,2,3 are feedbacks from various places, likely feedback to show clutch position, etc.

The system will likely need oil pressure to function, but once this is set up, it should be simple to run through the four SL combinations to see which ratios are available. The default is 1 : 1.9 (high), a low gear at 1 : 3.9 is available.

[Bryson]

I tried playing with SL combinations the other day but wasn’t able to observe any changes in speed. I’m going to table it for now while I work on getting the hardware into the car

[Jack Bauer]

Merged the pull request thanks.

[Domt177]

How much cooling does the inverter need, i.e what sized radiator will do?

[Jack Bauer]

I used a little 10 row oil cooler in the E65 for both inverter and gearbox. Couldn't get them to warm up.

[Bryson]

Regen code is merged as Damien said above. It would be great to have another user test this under some different conditions. I haven’t tested in car yet as my install is half baked.

[Bryson]

Alright, I was able to get the drivetrain installed in the car and the software seems to work as expected on the road, except for one thing…

I’m getting surging in throttle back/forth at somewhere around 2Hz. It happens at all tested speeds, up to about 3500rpm MG2 speed. Frequency doesn’t seem to change too much with speed. At first I thought it might be the regen code, but the prior file without regen exhibited the same symptoms after a reflash.

Has anyone else seen this before? I’ve got a pretty long throttle cable, so maybe I just need an RC filter on the throttle pedal?

[Bassmobile]

Has anyone else seen this before? I’ve got a pretty long throttle cable, so maybe I just need an RC filter on the throttle pedal?

What type of accelerator actuator are you using? Do the conductors have any shielding?

[Bryson]

One of these guys - https://www.evwest.com/catalog/product_ ... 83074e19da - apparently a 5k pot inside

I've terminated the shield to the same ground as the 5V ground, which I knew better than to do, but it worked fine with my last drivetrain. I'll re-terminate the shield to the inverter case tomorrow and cross my fingers.

[Bassmobile]

I've terminated the shield to the same ground as the 5V ground

There's your problem. Throw and RF choke on each end near termination also for good measure.

[Bryson]

Well I terminated the shield to chassis ground and added a common mode choke with two wraps, and the symptoms persist. No perceptible change unfortunately.

With some more seat time, it does seem related to lower throttle inputs, and goes away under heavier throttle. Maybe I’m fighting drivetrain slack?

[Bassmobile]

With some more seat time, it does seem related to lower throttle inputs, and goes away under heavier throttle. Maybe I’m fighting drivetrain slack?

Awe man sorry to hear that! Was hoping it was a simple fix. At least by adding the shielding you've reduced the variables.

Can you make video to help illustrate what is occurring when this "surging" as you called it happens.

Btw, What inverter model number are you using?

[Bryson]

By the numbers, it looks like I'm in low gear. Damien's videos show similar MG1 and MG2 speeds, slightly lower for MG2 than MG1. Perhaps that is related? It definitely caught me by surprise when the car laid down rubber from a stop!

Now how the hell do I get it into high gear is the question..

[arturk]

Now how the hell do I get it into high gear is the question..

High gear is default mode without any solenoids energized.

[Bryson]

Hm, maybe I'll just temporarily disconnect the pins, as I'm started up in the default LOW state for each solenoid. Is this what yours looks like when it's powered up?

Inverter is a G9200-30040 (Toyota) / G9201-30020 (Denso) part number

[arturk]

I have my own custom version so we cannot directly compare results.

However, at some point I did play with switching gears. I was able to switch between Low and High without any problems by energizing appropriate solenoids at stand still. I did some test switching gears while driving and while it was possible I learned it is very tricky to do it in smooth fashion while driving. I have abandoned this for now because High is really way to go unless you really need to make some tire smoke.

So, as I mentioned, without any solenoids engaged, my transmission is always in High.

I looked at the code I think you are running and it looks like that shifting is not implemented and all solenoids are off in both Low and High. Therefore you should be in High mode. I am little puzzled why not.
One interesting thing I see in your screenshot is PB1:ON, I do not remember what it indicates and unfortunately I cannot check at the moment what it is in my setup.

As far as RPM goes, in my setup I would be reaching 10000 RPMs around 60 MPH in Low and in High I can get up to around 130 MPH. Your results will differ but probably not by much.

[Bryson]

Yep, same here. 60mph max speed in low and it’s a little noisy. Would you mind sending me your code so I can see which solenoid combinations you’re energizing to shift gears? That might shed some light for me.

Edit: looks like in Damien’s videos all PB1,2,3 are ON. Odd

[Bassmobile]

I have my own custom version so we cannot directly compare results.

Please commit your contributions to a branch in the master repository and PUSH THE CODE!

There is less value added to this discussion if your code is off in a silo, inaccessible to the rest of us engineers. The only way that open source software survives is through open contributions. Keep that GIT cache clear and your commits up to date. Push!

Okay, stepping off my soapbox now. Hope you're feeling better btw.

[arturk]

Here is my the function for selecting gears:

Code: Select all

void setGear()
{
  if (RequestedGear ^ CurrentGear)    //gear shift requested
  {
    TorqueRestoreOK = false;          //put torque restore on hold
    TorquePercent = 0;                //reduce torque
    if (GearShiftInit = 0)
    {
      GearShiftInit = millis();
    }
    
    if(RequestedGear)                 //upshift into "High Gear"
    {
                                      //TODO: confirm torque reduction reading from MTH data
      //if (since_last_packet > 1000)   //wait for next 2 packages to be send to Inverter (1 every 1000us)
      if (millis() - GearShiftInit > 10)//wait 10ms
      {
        digitalWrite(TransSL1,LOW);
        digitalWrite(TransSL2,LOW);
      }
    
      //if(!digitalRead(TransPB1) ||    //when pressure is present on Brake 2
      //  abs(mg2_speed) < 100)         //or low RPM
      if (millis() - GearShiftInit > 20)//wait 10ms
      {
        CurrentGear = RequestedGear;  //update current 
        TorqueRestoreOK = true;       //allow to restore torque
        GearShiftInit = 0;
      }
    }
    else                              //downshift into "Low Gear"
    {
      if (millis() - GearShiftInit > 10)
      {
        digitalWrite(TransSL1,HIGH);
        digitalWrite(TransSL2,HIGH);
      }

      //if(!digitalRead(TransPB2) ||    //when pressure is present on Brake 2
      //  abs(mg2_speed) < 100)         //or low RPM
      if (millis() - GearShiftInit > 20)//wait 10ms
      {
        CurrentGear = RequestedGear;  //update current 
        TorqueRestoreOK = true;       //allow to restore torque
        GearShiftInit = 0;
      }
    }
  }
}

It worked fine at stand still and also while driving gently at modest speeds but was not smooth enough.
It needs refining for sure so use it as a guideline only, some comments may be useful.
One thing that is missing here I did not have time to test is control of the "SP" solenoid which I believe allows to modulate pressure. Perhaps it is a key to smooth shifting.

As I mentioned this comes from my highly customized software based on Damien's v7 which came way before "User friendly" version became available.
I do not have ability at the moment to integrate it with current codebase therefore I cannot push this code into repository.
Bryson if you cant tweak it to work with latest version of the code then go ahead and integrate it.

BTW, I am feeling better but it will take many more weeks before I can actually do something productive. I will get there though, thanks!

[Bryson]

Well it looks like I may have a hardware or software bug - both pins were being held to ground regardless of the state in software. I pulled the pins from the VCU and we’re now running in high gear B).

Would either of you mind sending your pin assignments for SL1 and SL2? I’m trying to rule out software and hardware simultaneously. Hope you’re well.

edit: Looks like hardware failure, which seems odd. Both gate voltages were at ground level and the mosfets were still on. I've ordered these as replacements: https://www.mouser.com/ProductDetail/ON ... BRjw%3D%3D

[arturk]

I am glad you are in High gear now

Here is pinout:

[Bryson]

Hey Damien, others,

You might want to check the whole batch of VCUs as it appears the wrong part was installed in locations IC1,3,4,7 on my board. The BSP75N installed components are internally shorted across the ground/source pin and tab by design instead of the drain pin. This led my controller to command the gearbox to always be in low gear, and for out1 and oil pump power to be always on. I’ll be replacing those on the board with the correct part numbers this weekend.

Is: BSP75N https://www.mouser.com/datasheet/2/196/ ... 225579.pdf

Should be: NCV8402ASTT1G (per V2 excel BOM) https://www.mouser.com/ProductDetail/ON ... BRjw%3D%3D

In other news, I’ve added software to use the Brake_In pin B2 as a low gear shift input, and to use Out_1 pin A17 as a brake light output to drive a relay whenever I’m using regen. This will hopefully prevent me from getting rear ended. Code is in my repo linked earlier in the thread.