WEBVTT 00:00.140 --> 00:07.070 At this point, we have all the components needed to start the control system of our robot in the simulated 00:07.070 --> 00:13.640 environment of gazebo, and send commands to the robot to see how it responds to those commands. 00:13.730 --> 00:16.340 So let's open a new terminal here. 00:16.340 --> 00:22.430 Let's go to the workspace and let's build it with Qualcomm Build. 00:23.810 --> 00:24.650 Perfect. 00:24.650 --> 00:32.240 Then in a new window of the terminal let's source the file setup bash that is in the install folder. 00:32.240 --> 00:38.030 And let's start the gazebo simulation of our robot with Ros2 launch. 00:38.210 --> 00:44.720 And from the Arduino board description package let's start the gazebo launch dot Pi. 00:47.150 --> 00:51.440 So this will start the simulation of our robot in the empty gazebo world. 00:51.440 --> 00:52.790 So here we go. 00:52.820 --> 00:54.380 This is our robot. 00:54.380 --> 01:00.440 And now within this world, we want to see how we can activate the gripper of our robot. 01:00.440 --> 01:01.850 So this one here. 01:01.850 --> 01:05.220 And so we need to start also the control system of the robot. 01:05.250 --> 01:07.440 So let's make this one a little bit bigger. 01:07.440 --> 01:09.540 And let's open a new window of the terminal. 01:09.540 --> 01:18.390 Also here let's source the file setup bash, and let's launch with Ros2 launch from the Arduino bot 01:18.420 --> 01:19.590 controller package. 01:19.590 --> 01:24.570 Let's start the controller.launch.py file that we have created. 01:24.570 --> 01:26.460 So let's press enter. 01:26.460 --> 01:29.550 And now we can see that as we started the controller. 01:29.550 --> 01:35.340 So if we make this one a little bit bigger we can see that actually the ARM controller, the gripper 01:35.340 --> 01:40.260 controller and also the joint state broadcaster are properly configured. 01:40.260 --> 01:41.790 And also they are active. 01:41.790 --> 01:46.500 So this means that we can start using them in order to move the simulated robot. 01:46.500 --> 01:51.540 And so this actually interacted with here the controller manager. 01:51.570 --> 01:58.170 And so here we can see also that the controller manager was able to activate and configure all the controllers. 01:58.170 --> 01:59.910 Also we can confirm this. 01:59.910 --> 02:06.090 So we can confirm that actually the control system of the robot is up and running by opening a new terminal. 02:06.090 --> 02:10.530 And we can use the command rose to control. 02:10.530 --> 02:16.620 So this is a command that is available thanks to the Ros2 control library and which we can use in order 02:16.620 --> 02:18.330 to interact with this library. 02:18.360 --> 02:24.450 And so in order to get information about the current status of the Ros2 control for our robot. 02:24.450 --> 02:30.930 So if we press tab twice, for example, we can see that we have all of these commands that are available 02:30.930 --> 02:36.240 in order to inspect and in order to interact with the Ros2 control library. 02:36.240 --> 02:42.450 For example, let's use the list controllers command. 02:42.450 --> 02:44.010 So let's press enter. 02:44.010 --> 02:49.560 And here we can see that all of these are the controllers that are currently active. 02:49.560 --> 02:54.660 So we can see that we have the joint state broadcaster the gripper controller and also the ARM controller. 02:54.660 --> 02:56.520 Here we have their types. 02:56.520 --> 03:02.280 So for example we now are interested just in the gripper controller that is of type forward command 03:02.280 --> 03:02.850 controller. 03:02.850 --> 03:06.350 And also we can see that all of them are active. 03:06.350 --> 03:11.760 Also we can use the command Ros2 Control list. 03:15.870 --> 03:19.170 Hardware components. 03:19.170 --> 03:20.610 And we can use this command. 03:20.610 --> 03:22.080 So let's press enter. 03:22.800 --> 03:23.460 Perfect. 03:23.460 --> 03:29.550 And this one provides us with all the hardware components that are now loaded in the gazebo simulation. 03:29.550 --> 03:31.860 So in the Ros2 control library for gazebo. 03:31.860 --> 03:37.080 And we can see that we have the joint one, the joint two, the three and the four. 03:37.080 --> 03:39.660 And all of them are actually available. 03:39.870 --> 03:45.870 And also we can use the command list hardware interfaces. 03:45.870 --> 03:47.430 So let's press enter. 03:47.430 --> 03:51.330 And here we get a list of all the hardware interfaces that now we have loaded. 03:51.330 --> 03:53.820 So we have the command interface. 03:53.820 --> 03:58.530 That is the way that we can send commands to the joints. 03:58.560 --> 04:01.410 And so we can see that we can send position commands. 04:01.410 --> 04:03.330 So to all the joints. 04:03.330 --> 04:05.250 And also we have the state interface. 04:05.250 --> 04:10.410 And also in this case we can see that the type of the state interface is a position state interface 04:10.410 --> 04:11.580 for all the joints. 04:11.580 --> 04:18.310 And this means that we will get the state of the robot in form of position, so we will know the position 04:18.310 --> 04:19.270 of the robot. 04:19.390 --> 04:28.150 Now I invite you also to try here all the other commands that are available in the Ros2 control library. 04:28.150 --> 04:33.250 So here, as you can see, all of these are other comments that you can use in order to interact with 04:33.250 --> 04:33.910 the library. 04:33.910 --> 04:38.320 As for sure, you will find yourself using this library. 04:38.320 --> 04:42.760 So the Ros2 control library for all your future projects. 04:42.760 --> 04:47.980 For now, let's just see how can we use the gripper controller? 04:47.980 --> 04:52.600 So this one here, in order to move our gripper in the simulated environment. 04:52.630 --> 04:58.240 To do so, we can use the Ros two topic list command. 04:58.270 --> 04:59.020 Perfect. 04:59.020 --> 05:04.480 And now among all the topics that are available we can see that here we have the gripper controller 05:04.480 --> 05:05.230 commands. 05:05.230 --> 05:08.950 And also here we have the ARM controller joint trajectory. 05:08.950 --> 05:13.690 And this means that we can move the arm by sending a full trajectory. 05:13.690 --> 05:20.010 So here with this interface here Or we can move the gripper by sending just a command. 05:20.010 --> 05:21.870 So let's do so. 05:21.900 --> 05:30.120 Let's move the gripper by publishing with Ros two topic poop in the gripper. 05:30.210 --> 05:32.220 Controller commands. 05:32.220 --> 05:32.880 Topic. 05:32.910 --> 05:33.450 Perfect. 05:33.480 --> 05:35.250 Now let's use tab twice. 05:35.250 --> 05:38.220 And so we can see that this one here is the interface. 05:38.220 --> 05:41.310 So the message that is accepted in this topic. 05:41.580 --> 05:43.950 So let's publish a message of this type. 05:43.950 --> 05:45.720 Then let's use the double quotes. 05:45.720 --> 05:47.910 Then let's press tab twice. 05:48.060 --> 05:48.780 Perfect. 05:48.810 --> 05:52.470 And so we can see that this is the empty prototype of this message. 05:52.470 --> 05:56.160 So let's type the letter L and let's press tab again. 05:56.160 --> 05:57.210 And so perfect. 05:57.210 --> 06:01.680 So this is an empty prototype of the float 64 Multiarray. 06:01.680 --> 06:07.920 And here the only field that we need to change is here the data field in which we want to send the command 06:07.920 --> 06:10.500 for the joint for of the robot. 06:10.500 --> 06:14.520 So the one that activates the gripper, this one here. 06:14.520 --> 06:18.030 And actually for example let's set it to minus one. 06:18.030 --> 06:23.440 We don't need to set a command for the joint five as it will move along with the joint four. 06:23.440 --> 06:29.740 So basically we are asking the joint four to move one radius so minus one radian. 06:29.890 --> 06:31.690 So let's press enter. 06:31.810 --> 06:37.660 And as we send this command we can see that both the fingers of the robot are opening. 06:37.780 --> 06:42.250 And so until they reach the position of minus one radian. 06:42.250 --> 06:46.840 And so we can see also that we send a command just for the joint four. 06:46.840 --> 06:53.200 So this one here, but also the joint five was moved because it simply copying the behavior of the joint 06:53.200 --> 06:53.860 four. 06:53.890 --> 06:58.900 Now we can also close the gripper by sending the message zero. 06:58.900 --> 07:02.410 So it will go back to the position zero. 07:02.410 --> 07:05.560 And as we can see here now the gripper is closing. 07:05.560 --> 07:09.190 So it's reaching the angle zero radians. 07:09.190 --> 07:10.120 Perfect. 07:10.120 --> 07:15.220 And so this confirms us that the control system of our robot and in this case the control system of 07:15.220 --> 07:18.400 the gripper is perfectly working. 07:18.400 --> 07:25.650 Now before closing this lesson however, remember that here in the Arduino bot controller, in the config 07:25.650 --> 07:27.510 and in the Arduino bot controllers. 07:27.510 --> 07:34.770 We are using a different interface for the gripper controller that is an interface of type forward command 07:34.770 --> 07:35.610 controller. 07:35.610 --> 07:39.780 And so thanks to this interface, we were able to simply send a command to the gripper. 07:39.780 --> 07:41.250 And the gripper was moving. 07:41.250 --> 07:47.130 But from now on instead of this we want to use this other interface here. 07:47.130 --> 07:49.050 So let's uncomment this row. 07:49.050 --> 07:54.420 And so we are going to use the same interface both to actuate the arm controller and also the gripper 07:54.420 --> 07:55.110 controller. 07:55.140 --> 07:57.990 And so this is a joint trajectory interface. 07:57.990 --> 08:01.290 Basically we will send a trajectory to the gripper. 08:01.290 --> 08:04.740 And this trajectory will tell the gripper where to be. 08:04.740 --> 08:07.200 So how to move at any moment in time. 08:07.320 --> 08:11.040 Also here we need to uncomment these parameters. 08:11.100 --> 08:12.000 Perfect. 08:12.000 --> 08:18.120 And instead we can remove this one that was only useful for the forward controller. 08:18.120 --> 08:20.100 So we can save also this file. 08:20.100 --> 08:25.950 And now from now on we are going to use the same interface for the gripper and also for the arm.