# Simulating Manual Control using Mavros **URL:** \ **Category:** Blue Robotics Software\ **Tags:** sitl, simulate\ **Created:** [November 16, 2017, 6:27am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745 "2017-11-16T06:27:26Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![MavNav](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@MavNav](https://discuss.bluerobotics.com/u/MavNav)\ **Post date:** [November 16, 2017, 6:27am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/1 "2017-11-16T06:27:26Z")
Hello, Let me start off by saying im a rookie at this pixhawk and mavros stuff. I am using Ardusub V3.5.1. My ultimate goal here is to make the pixhawk move my motors in any of the axes, X, Y and Z. Im running Ubuntu Mate on an ARMv7 chip. (ODroid XU3) Note that i am not using any localisation techniques. I simply want to command a movement in a certain direction. I have tried publishing to “/mavros/setpoint\_velocity/cmd\_vel” with no results. Of course, i armed it beforehand with “rosrun mavros mavsafety arm” Here is the code i got online to publish cmd\_vel: #include \ #include \ #include \ #include “geometry\_msgs/TwistStamped.h” #include “geometry\_msgs/Vector3Stamped.h” int M = 0; int L = 0; int main(int argc, char \*\*argv) { geometry\_msgs::TwistStamped msg; ros::init(argc, argv, “move\_pix”); ros::NodeHandle nh; ros::Publisher velocity\_message = nh.advertise\(“/mavros/setpoint\_velocity/cmd\_vel”,100); ros::Rate loop\_rate(10); while(ros::ok()){ msg.header.stamp = ros::Time::now(); msg.header.seq=1; ``` msg.twist.linear.x = 1; msg.twist.linear.y = 1; msg.twist.linear.z = 1; msg.twist.angular.x = 0; msg.twist.angular.y = 0; msg.twist.angular.z = 0; velocity_message.publish(msg); ros::spinOnce(); loop_rate.sleep(); M++; L++; ``` } return 0; } Can someone advise on how i should go about achieving my goal? Thanks a bunch 🙂 ---
**Author:** ![patrickelectric](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/patrickelectric/32/2162_2.png) [@patrickelectric](https://discuss.bluerobotics.com/u/patrickelectric)\ **Post date:** [November 16, 2017, 11:00am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/2 "2017-11-16T11:00:51Z")
Hi @MavNav, I’ll itemize each step to make sure that everything is correct 🙂 Probably will work with the real ROV, but I’ll write a simple guide to you to test with [SITL](http://ardupilot.org/dev/docs/sitl-simulator-software-in-the-loop.html). - Start SITL - `cd ardupilot/ArduSub` - `sim_vehicle.py -j4` - Connect mavros with SITL - `roslaunch mavros apm.launch fcu_url:=udp://0.0.0.0:14550@` - Arm the ROV and put it on guided mode. - `rosrun mavros mavsafety arm` - `rosrun mavros mavsys mode -c GUIDED` - It’ll appear `Mode changed.` Now, we should have everything prepared to send linear and angular messages. To make sure that everything is correct, we can subscribe in odom to see the drone position. - `rostopic echo /mavros/local_position/odom/pose` ```auto pose: position: x: -15.353191375732417 y: -2.969302654266354 z: -39.34264373779297 orientation: x: 0.0005757744895501046 y: 0.0023029090765363785 z: -0.4099183091346866 w: -0.9121191506210589 ``` Now, we can send a linear and angular reference with rospub. - `rostopic pub -r 10 /mavros/setpoint_velocity/cmd_vel geometry_msgs/TwistStamped "{header: auto, twist: {linear: {x: 10.0, y: 0.0, z: 0.0}, angular: {x: 0.0, y: 0.0, z: 0.0}}}"` And with this, you’ll [see the x go up](https://asciinema.org/a/TsR2jxvxLy4JYlcSpwdXjLsEk). ---
**Author:** ![MavNav](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@MavNav](https://discuss.bluerobotics.com/u/MavNav)\ **Post date:** [November 16, 2017, 2:09pm UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/3 "2017-11-16T14:09:48Z")
Hey! Thanks for replying. I do have a real ROV on hand to test with. If so where do i start off? Also another thing, I’m using an Odroid XU3 as my companion computer connected to the Pixhawk using USB so i’d presume no need for the URL IP thingy? ---
**Author:** ![patrickelectric](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/patrickelectric/32/2162_2.png) [@patrickelectric](https://discuss.bluerobotics.com/u/patrickelectric)\ **Post date:** [November 16, 2017, 2:19pm UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/4 "2017-11-16T14:19:28Z")
Are you using the /dev/ttyACM0 right ? that’s the default communication device of mavros, no need to set the ip address. You should: Start mavros normally, arm the vehicle and set guided mode, like in [Arm the ROV and put it on guided mode.](http://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/2) I recommend to test your code with SITL first, just to make sure that your part is running without problems. Odroid XU3 is a powerful computer, any special reason for using it ? ---
**Author:** ![MavNav](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@MavNav](https://discuss.bluerobotics.com/u/MavNav)\ **Post date:** [November 17, 2017, 2:59am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/5 "2017-11-17T02:59:54Z")
Yes im using /dev/tty/ACM0. I start mavros using “roslaunch bluerov apm.launch” and it succesfully connects. However, when i try to change the mode to guided, it times out with “TImed Out!”. I’ll try to work on SITL in the following days just as a proof of concept. No real reason for the Odroid except i just happen to have one on hand and i eventually plan to make my AUV fully autonomous with smach. ---
**Author:** ![MavNav](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@MavNav](https://discuss.bluerobotics.com/u/MavNav)\ **Post date:** [November 23, 2017, 5:24am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/6 "2017-11-23T05:24:39Z")
UPDATE 23/11/17: I’ve managed to get it working in SITL and it does move. I can’t get it to change modes when i just connect to the pixhawk directly. Could you help? ---
**Author:** ![patrickelectric](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/patrickelectric/32/2162_2.png) [@patrickelectric](https://discuss.bluerobotics.com/u/patrickelectric)\ **Post date:** [November 23, 2017, 11:55am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/7 "2017-11-23T11:55:15Z")
@MavNav take a look in `/diagnostics` for problems or check the [mavproxy](http://ardupilot.github.io/MAVProxy/html/index.html) console, probably something is restricting the mode. ---
**Author:** ![MavNav](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@MavNav](https://discuss.bluerobotics.com/u/MavNav)\ **Post date:** [December 2, 2017, 11:44am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/8 "2017-12-02T11:44:22Z")
Hey sorry it took awhile. These are my results when i echo the /diagnostics topic: ## header: seq: 104 stamp: secs: 1512215007 nsecs: 470157004 frame\_id: ‘’ status: ``` level: 0 name: mavros: FCU connection message: connected hardware_id: /dev/pixhawk:115200 values: - key: Received packets: value: 36094 - key: Dropped packets: value: 0 - key: Buffer overruns: value: 0 - key: Parse errors: value: 0 - key: Rx sequence number: value: 25 - key: Tx sequence number: value: 157 - key: Rx total bytes: value: 1022089 - key: Tx total bytes: value: 2983 - key: Rx speed: value: 11458.000000 - key: Tx speed: value: 17.000000 ``` - ## level: 0 name: mavros: Heartbeat message: Normal hardware\_id: /dev/pixhawk:115200 values: ``` key: Heartbeats since startup value: 133 ``` - key: Frequency (Hz) value: 1.037217 - key: Vehicle type value: Submarine - key: Autopilot type value: ArduPilotMega / ArduCopter - key: Mode value: MANUAL - key: System status value: Critical - ## level: 0 name: mavros: System message: Normal hardware\_id: /dev/pixhawk:115200 values: ``` key: Sensor present value: 0x0020FC07 ``` - key: Sensor enabled value: 0x00209C07 - key: Sensor helth value: 0x0020FC07 - key: 3D gyro value: Ok - key: 3D accelerometer value: Ok - key: 3D magnetometer value: Ok - key: 3D angular rate control value: Ok - key: attitude stabilization value: Ok - key: yaw position value: Ok - key: motor outputs / control value: Ok - key: AHRS subsystem health value: Ok - key: CPU Load (%) value: 32.6 - key: Drop rate (%) value: 0.0 - key: Errors comm value: 0 - key: Errors count #1 value: 0 - key: Errors count #2 value: 0 - key: Errors count #3 value: 0 - key: Errors count #4 value: 0 - ## level: 1 name: mavros: Battery message: Low voltage hardware\_id: /dev/pixhawk:115200 values: ``` key: Voltage value: 0.00 ``` - key: Current value: -0.0 - key: Remaining value: -1.0 I have observed that the system status is “Critical”. Does it have any effect on the mode change command timing out? ---
**Author:** ![patrickelectric](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/patrickelectric/32/2162_2.png) [@patrickelectric](https://discuss.bluerobotics.com/u/patrickelectric)\ **Post date:** [December 2, 2017, 1:01pm UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/9 "2017-12-02T13:01:12Z")
Hi @MavNav, critical appears when one of the failsafes are enable: battery, ekf and others. First, you’ll need to disable then to arm, after that try to send some rc commands via `/mavros/rc/override`. ---
**Author:** ![MavNav](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@MavNav](https://discuss.bluerobotics.com/u/MavNav)\ **Post date:** [December 2, 2017, 1:24pm UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/10 "2017-12-02T13:24:01Z")
Ah alright. How do i disable them? And i was sending messages to setpoint\_velocity/cmd\_vel. So do i just change the topic name to mavros/rc/override? ---
**Author:** ![patrickelectric](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/patrickelectric/32/2162_2.png) [@patrickelectric](https://discuss.bluerobotics.com/u/patrickelectric)\ **Post date:** [December 2, 2017, 1:39pm UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/11 "2017-12-02T13:39:23Z")
You can disable then with QGC. ![Screenshot from 2017-12-02 11-24-16](https://us1.discourse-cdn.com/flex019/uploads/bluerobotics/original/2X/1/1f6cfc9214725cf7cecaecf91b278d21a66ac8e6.png) (This parameters are only for test ! Do not use in a real case.) Try first to control the rc output using the manual mode to test what you are doing. ---
**Author:** ![MavNav](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@MavNav](https://discuss.bluerobotics.com/u/MavNav)\ **Post date:** [December 2, 2017, 5:49pm UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/12 "2017-12-02T17:49:31Z")
I’ve disabled arming checks as seen here: ![image](https://us1.discourse-cdn.com/flex019/uploads/bluerobotics/original/2X/7/7688c85de178ce507e7f3f657dcb6f2ac4b71d19.png) I get this on the terminal running mavros when i run the mode change command: “[WARN] [1512236670.910592758]: CMD: Unexpected command 11, result 4” Mode change to Guided still times out. I’m usng QGC on Windows to change parameters because i can’t get QGC to work in Linux. ---
**Author:** ![patrickelectric](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/patrickelectric/32/2162_2.png) [@patrickelectric](https://discuss.bluerobotics.com/u/patrickelectric)\ **Post date:** [December 4, 2017, 11:17am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/13 "2017-12-04T11:17:31Z")
Hi @MavNav, I have sent you a private message, probably this will be the fastest way to understand and solve your problem. ---
**Author:** ![frozeneye](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/frozeneye/32/2927_2.png) [@frozeneye](https://discuss.bluerobotics.com/u/frozeneye)\ **Post date:** [August 22, 2018, 5:48am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/14 "2018-08-22T05:48:22Z")
Hi @patrickelectric I have encounter the same problem. would you like to sent me the fastest way to understand and solve the problem?🤣🤣🤣 ---
**Author:** ![patrickelectric](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/patrickelectric/32/2162_2.png) [@patrickelectric](https://discuss.bluerobotics.com/u/patrickelectric)\ **Post date:** [December 4, 2017, 11:12am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/15 "2017-12-04T11:12:16Z")
Hi, Are you running a new version of ArduSub ? Are you able to send RC values in _rc/override_ in MANUAL mode ? My best regards, ---
**Author:** ![MavNav](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@MavNav](https://discuss.bluerobotics.com/u/MavNav)\ **Post date:** [December 5, 2017, 9:30am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/16 "2017-12-05T09:30:29Z")
Yes i am running the new version of Ardusub, 3.5.2. I don’t know what to send to Rc/Override so perhaps you could advise? On a side note, I thought i have to use guided mode to send cmd\_vel? ---
**Author:** ![patrickelectric](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/patrickelectric/32/2162_2.png) [@patrickelectric](https://discuss.bluerobotics.com/u/patrickelectric)\ **Post date:** [December 5, 2017, 10:32am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/17 "2017-12-05T10:32:32Z")
Ok, To send rc commands, try to use `rostopic pub -r 1 /mavros/rc/override mavros_msgs/OverrideRCIn '[1300, 1300, 1300, 1300, 0, 0, 0, 0]'` Yes, you’ll need to change the mode before sending cmd\_vel, try first to do basic communication, like sending rc commands and etc. Just to make sure that everything will work. ---
**Author:** ![MavNav](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@MavNav](https://discuss.bluerobotics.com/u/MavNav)\ **Post date:** [December 6, 2017, 7:19am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/18 "2017-12-06T07:19:59Z")
Good news! I have managed to get it to run as per your steps, in Manual mode, publishing the rc override code. How do i progress from here, to get to guided mode cmd vel? ---
**Author:** ![patrickelectric](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/patrickelectric/32/2162_2.png) [@patrickelectric](https://discuss.bluerobotics.com/u/patrickelectric)\ **Post date:** [December 6, 2017, 11:02am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/19 "2017-12-06T11:02:15Z")
Good ! Now, try first to set the guided and then arm the vehicle, maybe this can trick mavros to set the vehicle. ---
**Author:** ![MavNav](https://avatars.discourse-cdn.com/v4/letter/m/8c91f0/32.png) [@MavNav](https://discuss.bluerobotics.com/u/MavNav)\ **Post date:** [December 7, 2017, 3:29am UTC](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745/20 "2017-12-07T03:29:06Z")
Minor Problem: I cannot control the speed of Main Out 2 on the pixhawk using that command, it just runs at full speed. I got it to output correctly with speed control with only 1 ESC plugged in. But when i plug 2 in it runs it on Max output. Bigger Issue: Guided mode still times out when i try to initialise it both when running, and not. Mavros Terminal: [WARN] [1512617445.197459316]: CMD: Unexpected command 11, result 4 Command Terminal: ~$ rosrun mavros mavsys mode -c GUIDED Timed out! [Next page](https://discuss.bluerobotics.com/t/simulating-manual-control-using-mavros/1745.md?page=2)