PX4 SITL command takeoff not taking off in a stable manner

[ndepal]

I'm trying to control a drone (the iris model) in Gazebo through mavros. For this I have written a ROS node that sends commands/service requests on the mavros/cmd/arming, mavros/set_mode, mavros/cmd/takeoff, and mavros/mission/... to mavros.

I start the simulation with make posix_sitl_default gazebo and run mavros with roslaunch mavros px4.lauch fcu_url:=udp://:14540@127.0.0.1:14557, I can see that mavros can talk to PX4.

The problem that I have is that when I issue the command

ros::ServiceClient takeoff_client = ros_node_ptr_->serviceClient<mavros_msgs::CommandTOL>("mavros/cmd/takeoff");
        mavros_msgs::CommandTOL srv;
        srv.request.latitude = 0;
        srv.request.longitude = 0;
        srv.request.altitude = 10;
        srv.request.yaw = 0;
        srv.request.min_pitch = 0;

        if (!takeoff_client.call(srv)) {
            ROS_ERROR("Failed to takeoff.");
        } else {
            // still a failure
            if (!srv.response.success) {
                ROS_ERROR("Failed to takeoff (Error Code: %d)", srv.response.result);
            } else {
                ROS_INFO("Takeoff command sent");
            }
        }

The drone takes off and immediately pitches up, flying backwards at around 5 m/s. Sometimes it also scrapes the ground and flips.

If I just do commander takeoff in the PX4 shell, the drone takes off as expected. I have the same problem when I try to take off with rosrun mavros mavcmd takeoffcur 0 0 2.

Is there something I am doing wrong?

[Jaeyoung-Lim]

If you are running gazebo, I guess your initial local position (x,y,z)=(0,0,0) is not actually the (0,0,0) in the UTM coordinates( have you checked? )

Why not use the ~setpoint_position/local topic?

[LiYuanxing]

First, you have to go into the guided mode and take off.

[TSC21]

First, you have to go into the guided mode and take off.

@LiYuanxing wrong. First, PX4 does not have Guided mode. Second, does not have nothing to do with this issue.

[padmashree9110]

Hi, I am also facing this issue. As per above suggestion, I checked setpoint_position/local topic. But it is empty!

$ rostopic echo /mavros/setpoint_position/local

I tried setting this to (0,0,0), Still takeoff is not working as expected.