R V. User Manual. Remotely Operated Underwater Vehicle. Version 1.0 Author: Niklas Sundholm. Date: December 19, Status

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1 User Manual Version 1.0 Author: Niklas Sundholm Date: December 19, 2016 R V Status Reviewed Niklas Sundholm Approved Isak Nielsen

2 Project Identity Group Homepage: Client: Customer: Contact at SAAB: Course Responsible: Project Manager: Advisors: Isak Nielsen, Linköping University Phone: , Rikard Hagman, Combine Control Systems AB Phone: , Nicklas Johansson, SAAB Dynamics AB Phone: , Daniel Axehill, Linköping University Phone: , Isak Wiberg Phone: , Kristoffer Bergman, Linköping University Phone: , Group Members Name Responsibility Phone Elin Karlström Tests elika149 Klas Lindsten Hardware klali296 Fredrik Ljungberg Simulation frelj431 Erik Sköld Software erisk214 Niklas Sundholm Documentation niksu379 Isak Wiberg Project manager isawi527 Filip Östman Design filos433

3 Document History Version Date Changes made Sign Reviewer(s) First draft. EK, NS, KL, IW NS Second draft. NS, FÖ NS First version. EK EK

4 Contents 1 Software Requirements 1 2 Batteries and Battery Maintainance 1 3 Starting Up the ROV Hardware Setup Software Setup Shutting down the ROV 7 5 Operating the ROV Xbox Mode References by Script Mode Logging Data Displaying the Continuous Plots Setting Up the Aruco Markers Camera calibration Further Development of the ROV Parameter Estimation Known issues 16

5 User Manual 1 Notations GCS Global Coordinate System. GUI Graphical User Interface. LCS Local Coordinate System. MCS Marker Coordinate System. PCS Pool Coordinate System. ROV. 1 Software Requirements This section contains a list of software which is required to compile and operate the ROV. Ubuntu ROS Indigo Igloo rosserial (Indigo) rosserial arduino (Indigo) image common (Indigo) image transport (Indigo) joy (Indigo) 2 Batteries and Battery Maintainance This section describes how to use and maintain the Turnigy 5000mAh 4S 25C Lipo Pack battery, which is used to power the ROV. This is a high discharge battery, which means that it is possible to run all thrusters at the same time without disruptive voltage drops. The battery should only be used as long as the voltage is higher than 3.7 V per cell. The voltage for each cell can be read from the USB adapter display when the battery is connected to the USB adapter, which can be seen in Figure 1. The battery should never be charged unsupervised. See Figure 2 for instructions on battery charging.

6 User Manual 2 Figure 1: The voltage for each cell read from the USB adapter display when the battery is connected to the USB adapter.

7 User Manual 3 Figure 2: Charging the battery. Make sure that the battery is connected to the charger as displayed in the figure. 3 Starting Up the ROV This section describes the steps required to start and operate the ROV. 3.1 Hardware Setup 1. Connect the Ethernet cable to the workstation. 2. Connect the USB adapter to the battery as shown in Figure 3. Mind the polarity when connecting the USB adapter to the battery. The black cable from the battery should be connected to the (-) on the USB adapter. 3. Connect the Raspberry Pi to the USB adapter as shown in Figure Connect the ESC:s to the battery as shown in Figure Slide the electronics cradle, see Figure 6, gently into the ROV tube. 6. Remove the valve on the ROV tube cap, shown in Figure 9. If needed, apply some silicone grease on the O-rings of the cap. Slide the cap into the ROV tube and insert the valve again. 7. Fixate the ROV tube on the ROV with the velcro tape. An overview of the ROV and how the various parts are connected can be seen in Figure 7. Figure 8 shows how the different parts of the ROV cradle is connected underneath where the battery is fixed.

8 User Manual 4 Figure 3: Connecting the USB adapter to the battery. The black cable from the battery should be connected to the (-) on the USB adapter as shown in the figure. Figure 4: Connecting the Raspberry Pi to the USB adapter. Make sure that the Raspberry Pi is connected to the USB adapter as displayed in the figure.

9 User Manual 5 Figure 5: Connecting the ESC:s to the battery. Make sure that the ESC power cables are connected to the battery as displayed in the figure. Figure 6: How to slide the electronic cradle into the ROV.

10 User Manual 6 Figure 7: Overview of how the different parts of the ROV is connected. Figure 8: Overview of how the different parts of the ROV cradle is connected underneath.

11 User Manual 7 Figure 9: Valve located on the ROV s tube cap. 3.2 Software Setup To start the ROV, open a terminal window on the workstation and navigate to the catkin ws folder on the workstation and run the following scripts in this order:. / s t a r t r o v. sh Open a new terminal window and navigate to the catkin ws folder and run the following script:. / s t a r t w o r k s t a t i o n. sh Running this script will start the Aruco initiation, described in Section 6. In order to initialize the bias states to zero, open a new terminal and navigate to the catkin ws folder and run the script below while the ROV is standing still on the ground.. / c a l i b r a t e s e n s o r s. sh 4 Shutting down the ROV To shut the ROV down, run the following command in the terminal:. / shutdownrasp. sh If the ROV is not shut down correctly, the micro SD card in the Raspberry Pi could be damaged.

12 User Manual 8 Figure 10: Layout of the rqt GUI. The Dynamic Reconfigure tab can be found at the bottom of the window. Plotting of topics can be done by typing and adding the wanted topic in the Topic field located at the top of the window. 5 Operating the ROV There are two ways of generating reference signals for the ROV. By default, the references are set using the Xbox controller. This will be referred to as the Xbox mode. The other way to input reference signals is by running a script file, setreferences.sh (located in the catkin ws directory), referred to as the References by Script mode. To switch between these two modes, click the Dynamic Reconfigure tab in the bottom center of the workstation rqt window, see Figure 10. Select controller in the vertical column to the left. After selecting controller, a number of options for the controller will appear to the right of the column. Click the check box named controllers to make all options visible. The active control mode can be set by opening the controller dropdown menu and selecting the wanted controller. In the dropdown menu named Xbox the user can select between Xbox Mode (option named Yes) and References by Script (option named No). For a screenshot of these menus, see Figure 11. The controller parameters are adjusted by opening the file setcontrollerparameters.sh (located in the catkin ws directory) with a text editor. To load the parameters into the controller, run the file in a terminal window by typing:. / s e t C o n t r o l l e r P a r a m e t e r s. sh This must be done when the controller node is started (that is, after./startworkstation.sh has been run). 5.1 Xbox Mode To enable the Xbox mode, select Yes in the Xbox dropdown menu in Dynamic Reconfigure. In Xbox mode ManualControl should be enabled in the controller dropdown menu, see Figure 11. In this mode the ROV is controlled manually with the Xbox-controller.

13 User Manual 9 Figure 11: Example of how to set Xbox mode and controller ManualControl in Dynamic Reconfigure. Table 1 shows the Xbox-controller s various buttons/triggers configurations and description. Button/stick Left trigger Right trigger Left bumper Right bumper Left stick Right stick A button B button X button Y button Description Increase depth velocity reference. Decrease depth velocity reference. Roll rate negative. Roll rate positive. Translational velocities. Angular velocities. Enable the thrusters. Disable the thrusters. Disable depth velocity mode. Enable depth velocity mode. Table 1: Xbox-controller button/trigger configuration and description. The buttons A, B, X and Y need to be used in both Xbox Mode and References by Script Mode in order to enable/disable the thrusters and depth velocity reference channel. 5.2 References by Script Mode To enable References by Script mode, select No in the xbox dropdown menu in Dynamic Reconfigure, see Figure 12. The references are adjusted by opening the file setreferences.sh (located in the catkin ws directory) with a text editor. To load the references into the controller, run the file in a terminal window by typing:. / s e t R e f e r e n c e s. sh

14 User Manual 10 Figure 12: Example of how to set References by Script mode and controller LinVelAngVel in Dynamic Reconfigure. This must be done when the controller node is started (which it is when./startworkstation.sh has been run) and the References by Script mode has been selected. Note that the enable thrusters master switch (Xbox controller button A) must be used in this mode as well to run the system. If a reference in depth velocity is given, make sure that the active controller is LinVelAngVel and that the depth velocity reference channel has been enabled by pressing button Y on the Xbox controller. 5.3 Logging Data In order to record data write the following command in a new terminal:. / l o g. sh This enables logging of the topics sensor fusion/states, rovio/water pressure/data, rovio/- magnetometer/data, rovio/imu/data, rovio/thrusters and reference. Before the data recording starts it is possible to name the log file. Press ctrl+c to end the recording of data. 5.4 Displaying the Continuous Plots To plot data published on various topics the rqt GUI that shows up when running./startworkstation.sh can be used. Another option is to run the command rqt plot in a new terminal and a new rqt plot window will appear. To display a reference signal, write /reference/data in the topic field at the top of the window as is shown in Figure 10. To display states write /sensor fusion/states. To access certain data, add the wanted index number in hard brackets, see the example below. The index of the various references are presented in Table 2 and the index of the various states are presented in the Table 3.

15 User Manual 11 Example. To plot the data with the index 1 on topic /reference/data, type /reference/data[1] in the topic field and press the green plus symbol. Index Description 0 x-position in GCS 1 y-position in GCS 2 z-position in GCS 3 Roll angle of LCS in GCS 4 Pitch angle of LCS in GCS 5 Yaw angle of LCS in GCS 6 Linear velocity in LCS x direction, u lcs 7 Linear velocity in LCS y direction, v lcs 8 Linear velocity in LCS z direction, w lcs 9 Angular velocity around LCS x axis, p 10 Angular velocity around LCS y axis, q 11 Angular velocity around LCS z axis, r 12 Depth velocity Table 2: Description of the content in the messages sent on /reference/data. Index State description 0 Roll angle of LCS in GCS 1 Pitch angle of LCS in GCS 2 Yaw angle of LCS in GCS 3 Angular velocity around LCS x axis, p 4 Angular velocity around LCS y axis, q 5 Angular velocity around LCS z axis, r 6 Bias state for p 7 Bias state for q 8 Bias state for r 9 Depth 10 X position in PCS 11 Y position in PCS 12 Z position in PCS 13 Linear velocity in PCS x direction, u pcs 14 Linear velocity in PCS y direction, v pcs 15 Linear velocity in PCS z direction, w pcs 16 Linear velocity in LCS x direction, u lcs 17 Linear velocity in LCS y direction, v lcs 18 Linear velocity in LCS z direction, w lcs Table 3: Description of the content in the messages sent on /sensorfusion/states.

16 User Manual 12 6 Setting Up the Aruco Markers To navigate, the ROV uses so called Aruco markers. In order for the ROV to navigate, the markers positions need to be known by the ROV beforehand. The Aruco initiation will start after running./startworkstation.sh. All markers then have to be shown to the ROV. When the markers are shown to the ROV it is of great importance that the first seen marker is placed on a wall. It is also important that the first marker is not placed upside down. The arrow that is drawn on the backside of each marker should be pointing up. This is important since the first detected marker decides the orientation of the MCS. The other markers need to be placed up-right on a wall or can be placed on the bottom. When they are shown to the ROV it is necessary that a previously seen marker is visible simultaneously.

17 User Manual 13 Figure 13: Example of how to set up the Aruco markers in a pool.

18 User Manual 14 Figure 14: Aruco markers attached to ropes. It is important that the markers are mounted with the correct side up. This can be verified by checking that the small painted arrows on the back of the markers are pointing up.

19 User Manual Camera calibration A camera calibration needs to be performed when the ROV is in a new environment in order to achieve high performance from the vision system. This is done by running./startrov.sh followed by./startworkstation and then type the following command rosrun c a m e r a c a l i b r a t i o n c a m e r a c a l i b r a t o r. py s i z e 7x5 square image :=/ camera/ image raw camera :=/ then a GUI appears and the calibration can be started. Show a checkerboard to the camera and move the checkerboard around the entire image. When enough data is collected, press Calibrate and wait for the calibration parameters to show up in the terminal. Copy and paste the parameters to a file with the ending.ini. This calibration needs to be added to path to catkin ws/src/bluerov/launch/aruco mapping.launch. More information about the camera calibration can be found at calibration. 7 Further Development of the ROV When new code has been written and one wants to compile the code, navigate to the catkin ws folder on the workstation and run the command below to build the complete catkin workspace. catkin make To create a new ROS-package, navigate to the catkin ws/src folder on the workstation and run the following: c a t k i n c r e a t e p k g <package name> [ depend1 ] [ depend2 ] [ depend3 ] More information can be found on The package headers are in the folder < package name >/include and the source code is in the folder < package name >/src. Compilation options can be changed by modifing the file CMakeLists.txt in the folder /package name. 7.1 Parameter Estimation To estimate the unknown parameters in the ROV s motion model an extended Kalman filter is used. The main idea behind this method is to extend the state vector with some of the unknown parameters and hence let the parameters change each iteration. This is done in Matlab using the file EKF Estimator.m. The first user-modified input to this script is the name of the test-files that should be used. This is done by modifying bag filepaths to include the name of the called file and two time indices, corresponding to the desired start and final time. The script can handle multiple files simultaneously and by setting the variables nr sets and nr iter the user can choose the amount of data sets and the number of times the filter should run over each set. It is also easy to change which parameters that are currently being estimated by modifying the vector of strings called est names. To control the number of printouts the user can set the variable PRINT PROGRESS to either 0, 1 or 2, where 2 corresponds to the highest number of printouts. Other user set design parameters are the usual Kalman covariance matrices P 0, R and Q alongside the vector σ. A higher value of σ i decreases the sensitivity of the outlier rejection for the i:th measurement.

20 User Manual 16 8 Known issues The usage of Aruco under water has proven difficult at times since it only functions well under certain circumstances. In order to get good performance from Aruco it is important that the water environment is properly lit up, the markers are flat and not moving. The reflection of Aruco markers in the water s surface can be a big problem if they are detected, as it will give false measurements. Aruco tends to crash at times and the reason for this is unknown. In some pools this barely ever happens, while in others it happens often. Attempts to re-create the crash scenarios has been done without success. If Aruco crashes it has to be initialised again.