MP 2128G2 Heli Sensors calibration

[Janusz Ochoński]

Hello Everyone!

I try to run the autopilot MP2128HeliG2 in trueHWIL setup. After load a simulation to the xPC Target computer I run the Autopilot and I got a lots of errors from sensors. The message gathered from Terminal is:
[1B][2J[1B][0;0HFATAL ERRORS:
Watchdog CRC Mismatch[1B][K
x accl failed [1B][K
Accl Temperatures Failed[1B][K
GPS config error[1B][K
Compass is enabled but is not installed.[1B][K
[1B][K
WARNINGS:
Autopilot loaded with non-release code.[1B][K
[1B][K
Lockd 11.3V 0.0V
spd= 17
z acc=854
compass hdg=0 0 0 0
I tried to run the calibration trueHwil Control Centre program to calibrate sensors. When I load the callibration_2128.thprj file and tried to load it to run the simulation I got the error of different numbers of parameters between downloaded model to target PC and parameter file. In result I cannot load the model to xPC Target computer to run the calibration. In xPC Target I have this message:

Download started...
Download finished
Mismatch between model and kernel versions

Is the calibration proces necessary for those Horizon fatal errors? If Yes then how I can solve the problem with calibration program problem? 

Thanks for any advices
Regards

Janusz

[Kevin Surminski]

Hi Janusz,

Great! Let's focus on the AGL fatal error now. After performing the standard startup procedure and connecting in Horizon, open sensor monitor and add field 1089. This is the raw AGL reading in the units of ft*36.5. Let me know what the value is.

[Janusz Ochoński]

Hi Kevin, 

The values goes wild, more or less it looks like random numbers. I stored logs from two short runs. 

[Kevin Surminski]

Hi Janusz,

Field 1089 is not what it should be.
1) Can you connect an oscilloscope to J17 pin 3 and send me some screenshots of what this signal looks like? It's supposed to be a PWM signal.
2) Here's the AGL signal path: Digital interface J33 pin 53 to J17 pin 3 to sensorless autopilot P2 wiring harness AGL connector pin 3 to P2 pin 19. Verify this signal path.
3) Verify continuity between AGL connector pin 1 (ground) and sensorless autopilot PWR connector pin 1 (ground).

[Janusz Ochoński]

Hi Kevin, 

It's looks like this was the sinusoidal wave, not a random numbers. The files with numbers 0, 2 and 3 was measured at J17 pin 3, the  newfile1 was measured on J33 pin 53. There is a continuity between J33 pin 53 and J17 pin 3 up to the P2 pin 19. Also there was a continuity between AGL pin 1 and PWR pin 1. 

We were wondering about the calibration process that we perform earlier. When We get from You the Calibration_2015b project there was THWIL_Fixed_Wing.vrs file that we upload to the autopilot. Is there a difference in calibration process when we use Helicopter version of autopilot? If i understand correctly the calibration process is for finding parameters of sensors in TrueHWIL setup, and the same sensors should be simulated independly of the autopilot version. 

Best regards,

Janusz

[Kevin Surminski]

Hi Janusz,

Can you remove the lid of the digital interface box and send me a screenshot of the jumper locations?

Perform the standard start up procedure, then in the digital interface box, probe S16 with an oscilloscope and send me a screenshot of signal you see there. 

"We were wondering about the calibration process that we perform earlier. When We get from You the Calibration_2015b project there was THWIL_Fixed_Wing.vrs file that we upload to the autopilot. Is there a difference in calibration process when we use Helicopter version of autopilot? If i understand correctly the calibration process is for finding parameters of sensors in TrueHWIL setup, and the same sensors should be simulated independly of the autopilot version. "

There is no difference in the calibration process. 

[Janusz Ochoński]

Hi Kevin, 

You can download photo of the digital interface from :
https://drive.google.com/file/d/1PdpLFsUP5mEWKKemn2kXTdTnQ18CPmyW/v...

And the screenshots from oscilloscope are in attachment.

Regards,
Janusz

[Kevin Surminski]

Hi Janusz,

Your oscilloscope screenshots show a PWM signal with a high time of about 1.6 ms. For an AGL input, this corresponds to about 0.8 feet which seems right. Also I looked at the model and it specifies that the AGL signal is output on pin 16, NOT pin 53. It looks like there's an older version of the wiring harness where J33 pin 53 went to the AGL input on the sensorless autopilot. You have this version. And a newer version where J33 pin 16 went to the AGL input on the sensorless autopilot. So the newer model (which you are using) has the AGL on pin 16.

Therefore you need to make a couple of changes to the jumpers in your digital box.
1) Remove the jumper on AD53/S53.
2) Attach a jumper wire from S16 pin 1 or 2 to AD53 pin 1 or 2.
Send me a screenshot after you've done this so I can verify.

Then re-test. Connect the oscilloscope to J16 pin 3 and hopefully it will be the PWM signal now. And hopefully field 1089 will be around 30.

[Janusz Ochoński]

Hi Kevin, 

Here You have the photo:
https://drive.google.com/file/d/1Q09iMsK3I96TjNJpz1VmZPx399ce23_N/v...

And just for confirmation: "Then re-test. Connect the oscilloscope to J16 pin 3 and hopefully it will be the PWM signal now."
Did You meen AGL plug J17 pin 3? 

Regards,
Janusz

[Kevin Surminski]

Hi Janusz,

Your jumper wire looks correct. 

"Did You meen AGL plug J17 pin 3? "

Yes, I meant AGL plug J17 pin 3. Sorry about that.

[Janusz Ochoński]

Hi Kevin, 

The AGL fatal error finaly is gone, the values in signal monitor jumps between 0 and 34 but it looks like the Horizon interprete it correctly. I uploaded the screen from osciloscope and short log from the sensor monitor. The last fatal error is now only Pitch gyro. 

Best regards,
Janusz

[Janusz Ochoński]

And another questions about the modyfication in TrueHWIL interfaces. If we swith back to our old autopilot for the Fixed Wing that we bought in 2015, then we need to reverse those changes in the analog and digital interfaces, or it should work with those modifications? Also we now use the Horizon 3.7 then do we need an update of the firmware of this Fixed Wing autopilot to newer version (previously we used version 3.6)? 

Regards
Janusz

[Kevin Surminski]

Hi Janusz,

Regarding the AGL, the signal in the oscilloscope screenshot doesn't look as "square" as it should. And in your sensor log, I don't like how inconsistent the values are. The 0 values are expected. Let's keep an eye on it for now and move on solving the pitch gyro issue. 

Let's first determine if it's an issue with the self test or not. When the autopilot is powered on, it performs a self test of the gyros. There are self test (ST) lines that go high during this time. J21 pin 3 is ST2, J21 pin 4 is ST1_33. J21 pin 5 is ST1. I'd like you to connect your oscilloscope to these, perform the standard startup procedure. At the step where you power on the autopilot, watch the oscilloscope screen for activity in the 30 seconds after powering on the autopilot. Let me know what you find.  

I'd also like to see the pitch gyro raw and processed readings. Perform the standard startup procedure. Instead of connecting in Horizon, open a terminal program and record a log. After the POST report, type RRRR and wait 1 minute. Then type SSSS and wait 1 minute. If you see all zeros in the SSSS report, wait until the autopilot finishes initializing then you should see numbers. Wait 1 minute after you start seeing non-zero values. Send me this log. 

"And another questions about the modyfication in TrueHWIL interfaces. If we swith back to our old autopilot for the Fixed Wing that we bought in 2015, then we need to reverse those changes in the analog and digital interfaces, or it should work with those modifications?"

For the change in the analog interface, you should keep that change. For the change in the digital interface, it depends on what model is used. If you use the newer model where AGL is output on S16, then you keep those changes. If you use an older model where AGL is output on S53, then you need to revert that change. 

"Also we now use the Horizon 3.7 then do we need an update of the firmware of this Fixed Wing autopilot to newer version (previously we used version 3.6)? "

No. You can still connect to an autopilot running firmware version 3.6 with Horizon 3.7. I don't recommend transmitting or receiving a VRS using Horizon 3.7 to an autopilot running firmware 3.6. You should use Horizon 3.6 to do that. You can have Horizon 3.7 and 3.6 installed at the same time. They are separate.