Copter: in angle control GUIDED mode the drone keeps rotating on its yaw axis when told not to do so

[deb0ch]

Issue details

In GUIDED mode, using angle control with the SET_ATTITUDE_TARGET messages, the drone keeps rotating on its yaw axis.

It will first quickly go to a yaw angle (presumably the one set in the command's quaternion), and then will keep turning at a more or less constant rotation speed.

During another flight we even had a crash right when we passed the vehicle from LOITER to GUIDED, using the included code example with the yaw_rate at 2 in the parameters of send_attitude_target: the drone leaned very hard (maybe 45°) on both its pitch and roll axes, quickly losing altitude.

The WP_YAW_BEHAVIOR was set to 0 (WP_YAW_BEHAVIOR_NONE) for all those tests.

I took a couple videos using the example code below to illustrate the problem, I will include them if requested. Same with the logs, will try to find them if requested 😄

Version

3.4.6

Platform

• All
• AntennaTracker
• Copter
• Plane
• Rover

Airframe type

quad

Hardware type

Erle Brain 3

Code

import math
import time

import dronekit

copter = dronekit.connect('udp:10.0.0.42:5762', wait_ready=True)


def send_attitude_target(self, roll_angle=0.0, pitch_angle=0.0,
                         yaw_angle=0.0, yaw_rate=10, thrust=0.5):
    msg = copter.message_factory.set_attitude_target_encode(
        0,
        0,                                         # target system
        0,                                         # target component
        0b00000000,                                # type mask: bit 1 is LSB
        to_quaternion(roll_angle, pitch_angle, yaw_angle),    # q
        0,                                         # body roll rate in radian
        0,                                         # body pitch rate in radian
        yaw_rate,                                  # body yaw rate in radian
        thrust)                                    # thrust
    copter.send_mavlink(msg)


def to_quaternion(self, roll=0.0, pitch=0.0, yaw=0.0):
    """Convert degrees to quaternions."""
    t0 = math.cos(yaw * 0.5)
    t1 = math.sin(yaw * 0.5)
    t2 = math.cos(roll * 0.5)
    t3 = math.sin(roll * 0.5)
    t4 = math.cos(pitch * 0.5)
    t5 = math.sin(pitch * 0.5)
    w = t0 * t2 * t4 + t1 * t3 * t5
    x = t0 * t3 * t4 - t1 * t2 * t5
    y = t0 * t2 * t5 + t1 * t3 * t4
    z = t1 * t2 * t4 - t0 * t3 * t5
    return [w, x, y, z]


while True:
    if(copter and copter.mode == dronekit.VehicleMode("GUIDED")):
        send_attitude_target(0,  # roll
                             0,  # pitch
                             0,  # yaw_angle
                             0,  # yaw_rate
                             0.5)  # thrust
        print("attitude command sent")
    time.sleep(0.1)

With this sample code constantly running, we took off in LOITER mode and then passed to GUIDED during the flight.

[deb0ch]

Nevermind, this is not a bug but just us misusing the SET_ATTITUDE_TARGET command.

We did not know back then that depending on the type mask you can control the yaw with EITHER a rate OR an absolute angle, and wrongly assumed that we could request a specific angle to be reached at a specified rate.

Closing as not a bug and not related to Dronekit.

[ghost]

Can Erle Brain 3 perform connection with raspberry pi 3 alogn 4G ?

[borhanreo]

@ARPIT355 i completed connect raspberry pi 3 using 3G. and Control with Android application (Tower App)