ACRO mode and yaw rate commands

Blue Robotics Software
1

We are using the blue rov with a custom configuration - Imagine a four thruster quadcopter configuration underwater with the Pixhawk at pitch = 270 (pointing down).

In ACRO mode we are finding that yaw rate commands are disabled at certain angles and we are unable to control yaw rate. Pitch and roll rate control work fine at any angle, however.

We have disabled the Trainer in ACRO mode. I do not see any other parameters that may affect this problem in ACRO mode.

Is there a place in the ArduSub firmware where this is getting disabled?

Thanks in advance,
Tim

2

Can you please describe the situation more with details on how to reproduce the problem, or with a video?

4

Please provide your modified source code.

Also, Cool!

5

Source code is Ardusub 3.5.2 with only the following modification of the frame definition found in AP_Motors.cpp:

58%20PM
58%20PM1916×356 134 KB

Also changed the AP orientation in QGC to pitch270. Finally, note that all rate commands (pitch, yaw, roll and throttle) work perfectly in MANUAL mode as one would expect. It’s in ACRO that we are having an issue no yaw rate output in the above shown horizontal flight attitude.

6

Can you make a video demonstrating the operation in both modes?
Can you paste text that I can copy instead of typing these numbers in if I wanted to try?

If you are asking for help with a piece of software, then you should make it possible for others to run the same software in order to reproduce the problem and find answers.

7

PM’d you Jacob!

8

Here is a simple example of trying to set some yaw while in ACRO mode that doesn’t appear to be working.

from pymavlink import mavutil

#def main():
mavutil.set_dialect("ardupilotmega")
# Create the connection
#master = mavutil.mavlink_connection('udpin:192.168.2.1:14550')
master = mavutil.mavlink_connection('udpin:0.0.0.0:14550')
# Wait a heartbeat before sending commands
master.wait_heartbeat()

# Set all rc chans pwm to 1500 before arming:
data = [ 1500 ] * 8
master.mav.rc_channels_override_send(
	master.target_system, master.target_component, *data)

#############################################################set mode:
# Choose a mode
mode = 'ACRO'
# Get mode ID: return value should be 1 for acro mode
mode_id = master.mode_mapping()[mode]
# Set new mode
master.mav.set_mode_send(
master.target_system,
mavutil.mavlink.MAV_MODE_FLAG_CUSTOM_MODE_ENABLED,
mode_id)

############################################################## Arm
# http://mavlink.org/messages/common#MAV_CMD_COMPONENT_ARM_DISARM
master.mav.command_long_send(
master.target_system,
master.target_component,
mavutil.mavlink.MAV_CMD_COMPONENT_ARM_DISARM,
1,
1, 0, 0, 0, 0, 0, 0)


## Test setting some yaw
    
data[3] = 1600
master.mav.rc_channels_override_send(
	master.target_system, master.target_component, *data)
9

Note that same code works in MANUAL mode.

10

Is anyone able to get this simple bit of code working in ACRO mode?

Thanks in advance for any help!

11

Confirmed, as the roll/pitch approach +/- 90 degrees, the yaw controller output approaches zero. This is not how it should behave in acro. This is a bug.

https://github.com/bluerobotics/ardusub/issues/154

12

That link doesn’t work.

13

Hi @SaferHarbors,

That issue link is from when ArduSub was being developed by Blue Robotics as an unofficial fork of the ArduPilot repo. It has since been merged into the mainstream ArduPilot project, and the old issues were transferred over as well. In this case the link to the transferred issue is here - it seems it has still not been addressed.

I can bump it with our main ArduSub developer if it’s affecting something you’re trying to do, but can’t guarantee we’ll be able to spend time on it.