WEBVTT 00:00.200 --> 00:06.280 Finally, everything is ready to start the control system of our simulated robot in gazebo. 00:06.920 --> 00:14.920 The Urdf model is configured to load the gazebo Ros2 control plugin and the interface the simulated 00:14.920 --> 00:18.920 robot arm during gazebo with the Ros2 control library. 00:19.440 --> 00:25.840 We have defined the input and the output interfaces of each joint of the robot, and also we have configured 00:25.840 --> 00:32.840 the controller manager to interact with the robot's hardware and also with the other two applications. 00:33.480 --> 00:39.560 In this lesson, we will create a new launch file that starts all of this logic and functionalities. 00:40.120 --> 00:47.920 So let's open the Visual Studio Code and in the Arduino board controller let's create the new folder 00:47.920 --> 00:50.160 called launch. 00:50.440 --> 00:58.280 And here within this folder let's add a new file called controller dot launch dot pi. 00:58.600 --> 01:00.190 Since this is our a rush to launch. 01:00.230 --> 01:00.630 File. 01:00.990 --> 01:08.230 It is composed of a launch description object that we import from the launch library. 01:08.230 --> 01:11.350 So the launch description. 01:11.350 --> 01:18.390 And then we need to define the function generate launch. 01:20.870 --> 01:23.070 Description that returns. 01:25.230 --> 01:31.670 An object of type launch description which takes as input the list of all the functionalities that we 01:31.670 --> 01:33.550 want to start with this launch file. 01:34.030 --> 01:40.870 So let's start by launching the Robot State publisher node, which reads the Urdf model and publish 01:40.870 --> 01:43.310 its information into our Ros2 topic. 01:44.110 --> 01:50.430 We have already done this inside the Arduino bot description package inside the display dot launch, 01:50.430 --> 01:52.110 so let's copy this one. 01:52.150 --> 01:59.170 The node that is in charge of launching the robot state publisher and let's paste it here. 01:59.530 --> 02:02.850 Also let's remember to import the class node. 02:03.730 --> 02:08.170 So this one this instruction here to import the node. 02:08.610 --> 02:14.170 And now instead of using the model argument in the launch file as we did here. 02:14.570 --> 02:21.170 So where we enable the possibility to use a different model here in the controller launch, let's directly 02:21.170 --> 02:26.010 indicate the directory where the Urdf model of our robot is located. 02:26.370 --> 02:30.530 So let's import the OS library. 02:30.930 --> 02:40.490 And also let's import from the launch rose from the parameter description. 02:41.050 --> 02:48.410 Let's import the parameter value class and also from launch substitutions. 02:48.410 --> 02:57.190 So from launch substitutions let's import the class command. 02:58.510 --> 03:02.590 Now we need to assign a value to the robot. 03:05.390 --> 03:06.430 Description variable. 03:06.430 --> 03:09.030 So before it is used let's assign a value. 03:09.790 --> 03:15.550 And so here we need to indicate the directory where the Urdf model of the robot is located. 03:16.230 --> 03:19.070 So let's use a parameter value. 03:19.070 --> 03:21.590 So let's create a new object of this type. 03:21.910 --> 03:27.950 Within this one let's run a new command and the command that we want to run. 03:28.310 --> 03:30.630 Let's insert this one within a list. 03:31.190 --> 03:38.310 And so we want to run the command zero to convert first the model into a plain urdf model. 03:38.550 --> 03:44.910 And then we need to pass the full path of the Urdf model so we can use the function join. 03:47.030 --> 03:47.510 Okay. 03:47.830 --> 03:52.710 And here let's also remember to import the get package share directory. 03:52.710 --> 03:54.870 So from amend. 03:54.870 --> 03:57.660 Int index Python. 03:58.500 --> 04:08.060 From the packages module, let's import the get package share directory and we can use it here within 04:08.060 --> 04:09.180 the join function. 04:12.380 --> 04:16.700 To get access to the Arduino bot. 04:18.980 --> 04:20.020 Description. 04:23.460 --> 04:26.980 Package in which we have created the Urdf model. 04:27.540 --> 04:35.540 Then once we are in the Arduino bot description package, let's access to the Urdf folder and then within 04:35.540 --> 04:42.940 this folder let's access to our file that we called Arduino bot dot u. 04:44.980 --> 04:45.260 Dot. 04:46.540 --> 04:48.660 And also we want this command. 04:48.700 --> 04:56.210 So here we want this to be loaded with a value type Value type of a string. 04:56.210 --> 04:57.770 So str. 04:58.690 --> 05:02.010 Now the robot state publisher is completed. 05:02.450 --> 05:09.210 Before spawning the controllers that we defined in the Arduino bot controllers YAML configuration file. 05:09.650 --> 05:13.890 So actually before loading all the controllers that we defined here. 05:13.890 --> 05:20.530 So the arm controller and the gripper controller we first need to start another node that is available 05:20.530 --> 05:23.010 in the controller manager package. 05:23.010 --> 05:27.570 And that actually manages and supervises all of these controllers. 05:28.010 --> 05:29.450 So let's start a new node. 05:30.210 --> 05:33.690 So let's create a new instance called controller Manager. 05:34.090 --> 05:36.850 And this is an instance of the node class. 05:37.130 --> 05:37.810 Perfect. 05:37.810 --> 05:45.970 And we can use this one in order to start from the package that is the controller manager package. 05:46.130 --> 05:54.270 So from this one here we can start the executable that is the Ros2 Control node executable. 05:54.710 --> 05:57.430 And for this one here we can set some parameters. 05:57.870 --> 06:02.190 So we can set a list of parameters in order to configure this node here. 06:02.190 --> 06:05.510 So the Ros2 control node starting from the parameter. 06:05.870 --> 06:07.910 So here let's create a dictionary. 06:08.190 --> 06:14.310 And let's define the parameter that is called the robot description parameter. 06:14.470 --> 06:18.790 And this one will contain the urdf description of the robot. 06:19.070 --> 06:21.750 And so we can actually use this variable here. 06:21.750 --> 06:25.310 So we already loaded the urdf of our robot. 06:25.310 --> 06:26.270 So this one here. 06:26.270 --> 06:28.910 And we have already stored it in this variable. 06:28.910 --> 06:30.670 So in the robot description variable. 06:30.910 --> 06:35.550 And now we can use it in order to set a value for this parameter here. 06:35.550 --> 06:41.150 So we can simply set this variable so the robot description variable equal to the robot description 06:41.150 --> 06:41.750 parameter. 06:41.750 --> 06:44.670 So equal to this variable here then also. 06:44.710 --> 06:48.230 So finally after this variable here we can also set. 06:48.230 --> 06:52.700 So we can also provide the full directory to this configuration file here. 06:52.700 --> 06:53.900 So to the Arduino board. 06:53.940 --> 07:00.580 Controllers YAML so that the controller manager can be configured using these parameters here. 07:00.580 --> 07:05.740 So using these parameters here that we have defined in this configuration file. 07:06.540 --> 07:16.020 So here in order to provide the full directory to this file here we can use the OS path join function. 07:16.220 --> 07:22.980 And now here we can use the get package share directory in order to access the directory of the Arduino 07:22.980 --> 07:24.260 bot controller package. 07:27.660 --> 07:33.700 And then from this package so we can go to the config folder and from the config folder. 07:33.940 --> 07:36.340 So here we want to load this file here. 07:36.620 --> 07:43.860 So the Arduino bot controllers dot YAML file. 07:44.300 --> 07:44.980 Perfect. 07:45.140 --> 07:51.360 And now here with this one here we have correctly started and configured the controller manager. 07:51.680 --> 07:57.520 And now finally, for each of the controllers that we created and that we configured here. 07:57.720 --> 08:03.280 So for the ARM controller, for the gripper controller and also for this one here. 08:03.280 --> 08:08.960 So for the joint state broadcaster we can create a new node that actually starts. 08:08.960 --> 08:13.240 So that spawns each controller in the controller manager. 08:13.800 --> 08:19.320 So back here let's create a new instance that is called joint state. 08:23.240 --> 08:23.920 Spawner. 08:24.440 --> 08:26.440 So this is an instance of the node class. 08:26.880 --> 08:31.920 And we can use this node in order to start again from the package. 08:34.360 --> 08:35.920 That is the controller manager. 08:36.040 --> 08:43.480 So from this package here we can start the executable that is called the spawner executable. 08:43.800 --> 08:47.560 And so now we want to use this first instance of this node. 08:47.560 --> 08:51.020 So this instance of the spawner node in order to spawn. 08:51.020 --> 08:53.380 So in order to start this one here. 08:53.380 --> 08:56.260 So the joint state broadcaster controller. 08:56.820 --> 08:58.980 So here we can set some arguments. 09:00.820 --> 09:02.420 And this is a list of arguments. 09:02.660 --> 09:05.140 And so here let's start. 09:05.140 --> 09:12.420 So let's set the name of the controller that we want to start using this node which is the joint state. 09:14.700 --> 09:15.620 Broadcaster. 09:15.740 --> 09:19.860 And so actually this name here should match this one here. 09:19.860 --> 09:24.380 So the one that we have defined in the controller manager and also that we have configured. 09:24.420 --> 09:28.220 And so that we have specified which is the controller that it should load. 09:28.820 --> 09:39.060 Also here are the arguments that we need to set so we can set the flag controller manager perfect. 09:39.340 --> 09:47.170 And also we can set the namespace which is again controller Manager. 09:47.210 --> 09:48.970 And so this is just to set. 09:49.010 --> 09:51.530 So in order to link this one here. 09:51.530 --> 09:52.650 So this is pointer. 09:52.650 --> 09:57.570 So we are saying that we want to spawn this controller here into the controller manager. 09:57.970 --> 10:01.090 Now actually we need to use the same instruction. 10:01.090 --> 10:04.770 So we need to use the same node in order to start. 10:04.770 --> 10:07.810 So in order to spawn the remaining two controllers. 10:08.010 --> 10:11.170 So the arm controller and the gripper controller as well. 10:11.650 --> 10:15.850 So we can copy this instruction and we can paste it twice. 10:16.250 --> 10:17.330 So here we go. 10:17.370 --> 10:20.690 We have paste it twice and let's call the first one. 10:21.530 --> 10:25.770 Let's call it our controller spawner. 10:26.010 --> 10:29.810 And here we want to use this one in order to spawn the controller. 10:29.810 --> 10:31.930 So this one here the ARM controller. 10:32.050 --> 10:33.130 So we can copy it. 10:33.410 --> 10:36.370 And we can paste it here in the list of the arguments. 10:36.570 --> 10:40.130 And also in this case we want to spawn it into the controller manager. 10:40.570 --> 10:42.610 Now for the last node here. 10:42.610 --> 10:49.440 So let's call it instead Gripper controller spawner. 10:49.680 --> 10:52.040 And with this note here we want to start instead. 10:52.040 --> 10:54.240 So we want to spawn this one here. 10:54.240 --> 10:55.800 So the gripper controller. 10:55.800 --> 10:58.840 So let's copy it and let's paste it here. 10:58.840 --> 11:03.520 So in order to spawn the gripper controller into the controller manager. 11:04.120 --> 11:07.080 Now with this we have declared all the instructions. 11:07.080 --> 11:12.080 So all the nodes that we need in order to start the control system for our robot. 11:12.440 --> 11:19.240 So now in order to actually start using all of these classes so all of these objects, we need to declare 11:19.240 --> 11:20.000 them here. 11:20.240 --> 11:23.840 So in the list of the launch description class constructor. 11:24.320 --> 11:27.640 So let's start with the robot state publisher node. 11:27.640 --> 11:29.360 So let's first start this node. 11:29.840 --> 11:31.160 Then we can start. 11:31.200 --> 11:33.640 So as you can see here the controller manager. 11:35.520 --> 11:43.040 Then after the controller manager we can spawn the three controllers namely the joint state broadcaster 11:43.460 --> 11:49.020 Then the ARM controller and finally also the gripper controller spawner. 11:49.460 --> 11:50.140 Perfect. 11:50.500 --> 11:54.940 So with this we have completed our controller launch.py file. 11:54.940 --> 11:59.980 So this one here that in the order starts the controller manager. 12:00.260 --> 12:04.540 And then it spawns the three controller that we have configured. 12:04.540 --> 12:10.540 So the ARM controller, the gripper controller and the joint state broadcaster that simply will publish. 12:10.540 --> 12:13.580 So will provide the current state for each joint. 12:13.940 --> 12:17.220 So we can save this file and we can install it. 12:17.220 --> 12:23.220 So as we have created a new folder namely the launch folder in which we have created this file, we 12:23.260 --> 12:27.020 also need to install it so we can open the file cmake list. 12:27.300 --> 12:33.420 And here along with the config folder we also want to install the launch folder. 12:33.420 --> 12:39.460 So apart from installing the Arduino bot controllers let's also install here the controller launch dot 12:39.460 --> 12:45.410 Pi so that we can use the Ros2 launch command in order to start this file here. 12:45.810 --> 12:53.210 Then also as here in this launch file here, we have used some dependencies from the robot estate publisher 12:53.210 --> 12:55.250 and from the controller manager package. 12:55.410 --> 12:57.290 We need to declare them here. 12:57.530 --> 13:00.650 So we need to go in the package dot XML. 13:01.090 --> 13:09.210 And so we need to add a execution dependency from the Ros2 launch package. 13:09.610 --> 13:17.090 Then also we need another execution dependency from the robot estate publisher node. 13:17.330 --> 13:18.050 Perfect. 13:18.090 --> 13:19.330 We also need another one. 13:19.330 --> 13:26.610 So another execution dependency from the package which we have used in order to convert the exact model 13:26.610 --> 13:29.290 of our robot into a plain Urdf model. 13:29.690 --> 13:32.490 And finally, let's add another execution dependency. 13:34.850 --> 13:36.770 From the Controller manager node. 13:37.050 --> 13:37.730 Perfect. 13:37.730 --> 13:40.850 So with this also this file is completed and we can save it.