Simple script using mavros setpoint_position

@sprained_ankle wrote:

Hi i'm new to mavros, and I'm trying to use mavros's setpoint_position command. I understand it is a translation of mavlink's SET_POSITION_TARGET_LOCAL_NED. I cam across PX4's tutorial on how to use it, but I can't seem to for the life me get it to work on APM. I am testing using SITL with gazebo. Here is my code
/**
* @file nedTest.cpp
*/

#include <fstream>

#include <ros/ros.h>
#include <mavros_msgs/CommandBool.h>
#include <geometry_msgs/PoseStamped.h>
#include <mavros_msgs/SetMode.h>
#include <mavros_msgs/State.h>

mavros_msgs::State current_state;
void state_cb(const mavros_msgs::State::ConstPtr& msg){
    current_state = *msg;
}

int main(int argc, char **argv)
{
    ros::init(argc, argv, "offb_node");
    ros::NodeHandle nh;

    ros::Subscriber state_sub = nh.subscribe<mavros_msgs::State>("mavros/state", 1, state_cb);
    ros::Subscriber rng_sub = nh.subscribe<sensor_msgs::Range>("mavros/rangefinder/rangefinder",1,rng_cb);

    ros::Publisher local_pos_pub = nh.advertise<geometry_msgs::PoseStamped>
            ("mavros/setpoint_position/local", 10);
    //ros::Publisher att_pub = nh.advertise<mavros_msgs::AttitudeTarget>("mavros/setpoint_raw/attitude", 10);

    ros::ServiceClient arming_client = nh.serviceClient<mavros_msgs::CommandBool>("mavros/cmd/arming");
    ros::ServiceClient set_mode_client = nh.serviceClient<mavros_msgs::SetMode>("mavros/set_mode");

    //the setpoint publishing rate MUST be faster than 2Hz
    ros::Rate rate(20.0);

    // wait for FCU connection
    while(ros::ok() && current_state.connected){
        ros::spinOnce();
        rate.sleep();
    }

    geometry_msgs::PoseStamped pose;
    pose.pose.position.x = 0;
    pose.pose.position.y = 0;
    pose.pose.position.z = 2;


    //send a few setpoints before starting
    for(int i = 100; ros::ok() && i > 0; --i){
	local_pos_pub.publish(pose);
        ros::spinOnce();
        rate.sleep();
    }

    mavros_msgs::SetMode offb_set_mode;
    offb_set_mode.request.custom_mode = "GUIDED";

    mavros_msgs::CommandBool arm_cmd;
    arm_cmd.request.value = true;

    ros::Time last_request = ros::Time::now();

    while(ros::ok()){
        if( current_state.mode != "GUIDED" && (ros::Time::now() - last_request > ros::Duration(5.0))){
            if( set_mode_client.call(offb_set_mode)){
                ROS_INFO("Offboard enabled");
            }
            last_request = ros::Time::now();
        } else {
            if( !current_state.armed && current_state.mode == "GUIDED" && (ros::Time::now() - last_request > ros::Duration(5.0))){
                if( arming_client.call(arm_cmd) && arm_cmd.response.success){
                    ROS_INFO("Vehicle armed");
                }
                last_request = ros::Time::now();
            }
        }

	local_pos_pub.publish(pose);

    ros::spinOnce();
    rate.sleep();
    }

    return 0;
}

I substituted "OFFBOARD" mode for APM's "GUIDED" mode. The original tutorial I followed is https://dev.px4.io/en/ros/mavros_offboard.html

I am either doing something really simple wrong, or I have a big misconception of what should work. Thanks in advance!

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