\documentclass[onecolumn,letterpaper,11pt]{article} %=================================================================== % Include common packages, environments, counters etc \input{./common_latex/common_latex_packages} \input{./common_latex/common_latex_lab_format} \input{./common_latex/common_latex_definitions} %=================================================================== \begin{document} \wikidoc{file=MCP.Lab03IntroHelm} \wikidoc{auth=mikerb@mit.edu} %=================================================================== % Build the Cover Page in an environment style easy for wiki parsing \begin{labcover} \labtitle{Lab 3 - Introduction to the Helm} \vspace{0.1in} %\labcourse{2.680 Unmanned Marine Vehicle Autonomy, Sensing and Communications} \vspace{0.1in} \labpng{0.7}{figs_common/header.png} \labdate{Nov 17-21 2025} \vspace{0.1in} \labauth{Michael Benjamin, mikerb@mit.edu} \labauth{Dept of Mechanical Engineering, MIT, Cambridge MA 02139} \labtoc{footnotesize} \end{labcover} %=================================================================== % Add a blank page so first body page is on the right when doubleside \blankpage %=================================================================== % Begin the body of the text %=================================================================== \section{Overview and Objectives} \label{sec_overview} %=================================================================== This lab will introduce the IvP Helm to new users. It assumes nothing regarding prior experience with the Helm, other than the material included in the accompanying lecture "Introduction to the IvP Helm". The goals of this lab are to (a) understand the role of mission files (.moos) and behavior files (.bhv) in constructing new missions, (b) get comfortable with different ways to generate mission changing events, with endflags, \app{pMarineViewer} and the \app{uTimerScript}, (c) explore the \app{iSay} MOOS App, (d) explore the StationKeeping behavior. \begin{labinfo} %\labinfoheader{Topics:} \begin{packed_itemize}[2] \item Mission and Behavior Files \item Adding new behaviors to a mission \item Behavior endflags \item Waypoint behavior wptflags \item SationKeep behavior \item The iSay MOOS App \item The uTimerScript MOOS App \end{packed_itemize} \end{labinfo} \subsection*{Preliminaries} \label{prelims} All exercises begin by copying an existing mission folder (containing an \var{alpha.moos} and \var{alpha.bhv} file. Each folder contains a new mission variation. In this lab we will create the following missions: \begin{packed_itemize} \item \var{s2\_alpha}: By copying \var{s1\_alpha}, then modifying \item \var{s3\_alpha}: By copying \var{s2\_alpha}, then modifying \item \var{s4\_alpha}: By copying \var{s3\_alpha}, then modifying \item \var{s5\_alpha}: By copying \var{s2\_alpha}, then modifying \item \var{s6\_alpha}: By copying \var{s1\_alpha}, then modifying \item \var{s7\_alpha}: By copying \var{s6\_alpha}, then modifying \end{packed_itemize} \vspace{0.1in} \noindent To prepare, create your own missions folder, \var{missions\_lab}, and put all your work in this folder. The folder and the first mission variation can be created as below: \vspace{0.1in} \begin{consoleverb} $ cd $ mkdir missions_lab $ cp -rp moos-ivp/ivp/missions/s1_alpha missions_lab/s2_alpha \end{consoleverb} %====================================================================== \newpage \section{Exercises} %====================================================================== %====================================================================== \subsection{Exercise 1 - Add a New Behavior to the Alpha Mission} \label{sec_s2} In this exercise the goal is make a version of the Alpha mission that uses another waypoint behavior to perform a second survey before returning. It should look something like: \vspace{0.1in} \begin{figure}[H] \centering \includegraphics[width=0.75\textwidth]{figures/s2_alpha.png} \caption{{\bf s8\_alpha:} Using the Loiter Behavior} \label{fig_s8} \end{figure} \vspace{0.1in} \noindent You will need to do the following steps: \begin{packed_itemize} \item Copy the \var{s1\_alpha} mission, naming it \var{s2\_alpha} \item Add second Waypoint survey behavior \item Make the end flags for the first behavior trigger the second survey behavior. \item Make the end flags for the second behavior trigger the return behavior \end{packed_itemize} \vspace{0.1in} \noindent For the second survey behavior, give it the name \var{"west\_wpt\_survey"}. And give it the survey points below. Give a run condition requiring the survey region mode (given by the \var{REGION} MOOS variable) is \var{"west"}. Finally give it an end flag that triggers the return home behavior. The relevant parameters are: \begin{fileverb} //---------------------------------------------- Behavior = BHV_Waypoint { . . . name = west_wpt_survey condition = REGION = west endflag = RETURN = true points = -35,-65 : -35,-125 : 20,-125 : 20, -65 . . . } \end{fileverb} \vspace{0.1in} \noindent For the first survey behavior, give it the name \var{"east\_wpt\_survey"}. Give a run condition requiring the survey region is \var{"east"}. Finally give it an end flag that triggers the second survey behavior. The relevant parameters are: \begin{fileverb} //---------------------------------------------- Behavior = BHV_Waypoint { . . . name = east_wpt_survey condition = REGION = east endflag = REGION = west points = 60,-40 : 60,-160 : 150,-160 : 180,-100 : 150,-40 . . . } \end{fileverb} \vspace{0.1in} \noindent Lastly, you need to initialize the survey region to be east initially. At the top of the behavior file: \vspace{0.1in} \begin{fileverb} //-------- FILE: alpha.bhv ------------- initialize DEPLOY = false initialize RETURN = false initialize REGION = east \end{fileverb} \vspace{0.1in} \noindent The end result when properly working should look like: \begin{figure}[H] \centering \includegraphics[width=0.88\textwidth]{figures/s2_alpha_gif.png} \caption{The \var{s2\_alpha} mission in final working state.} \label{fig_s2_alpha_gif} \gif{figures/s2_alpha.gif} \end{figure} %====================================================================== \newpage \subsection{Exercise 2 - Add Command and Control Switches to pMarineViewer} \label{sec_s3} In this exercise the goal is make a version of the Alpha mission that requires the user to command the vehicle between the east and west regions. Otherwise the vehicle will remain surveying in its current region indefinitely. \vspace{0.1in} \noindent You will need to do the following steps: \begin{packed_itemize} \item Copy the \var{s2\_alpha} mission, naming it \var{s3\_alpha} \item Reconfigure each survey behavior to repeat forever \item Configure \app{pMarineviewer} to have two new buttons for commanding the vehicle between the east and west regions \end{packed_itemize} \vspace{0.1in} \noindent To change the survey behaviors to repeat forever, change the repeat paramter to be \var{"forever"} \begin{fileverb} //---------------------------------------------- Behavior = BHV_Waypoint { . . . repeat = forever . . . } \end{fileverb} \vspace{0.1in} \noindent The \app{pMarineViewer} app can be configured to add additional buttons besides the \var{DEPLOY} and \var{RETURN} buttons in the Alpha mission. The documentation for \app{pMarineViewer} can be found here: \urlx{http://oceanai.mit.edu/ivpman/apps/pMarineViewer} \vspace{0.1in} \noindent The \app{pMarineViewer} buttons are added as below. \begin{fileverb} //---------------------------------------------- ProcessConfig = pMarineViewer { . . . button_three = WEST # REGION=west button_four = EAST # REGION=east . . . } \end{fileverb} \vspace{0.1in} \noindent The end result when properly working should look like below. Note the buttons and the button pushes by the user. \begin{figure}[H] \centering \includegraphics[width=0.88\textwidth]{figures/s3_alpha.png} \caption{The \var{s3\_alpha} mission in final working state.} \label{fig_s3_alpha} \gif{figures/s3_alpha.gif} \end{figure} %====================================================================== \newpage \subsection{Exercise 3 - Use uTimerScript to Control Mission State} \label{sec_s4} In this exercise the goal is to further modify the previous Alpha mission where the vehicle changes between east and west based on the output of a script, running in the \app{uTimerScript} MOOS Application. \vspace{0.1in} \noindent You will need to do the following steps: \begin{packed_itemize} \item Copy the \var{s3\_alpha} mission, naming it \var{s4\_alpha} \item Add \app{uTimerScript} to the list of apps launched in the mission, inside the Antler configuration block of alpha.moos. \item Configure \app{uTimerScript} with a simple script to switch between east and west mission every 90 seconds. \end{packed_itemize} \vspace{0.1in} \noindent The \app{uTimerScript} documentation can be found here: \urlx{http://oceanai.mit.edu/ivpman/apps/uTimerScript} \vspace{0.1in} \noindent The timer script for this exercise is below: You can copy it into your mission file, but try to understand the configuration parameters by reading the documentation. \begin{fileverb} //------------------------------------------ // uTimerScript config block ProcessConfig = uTimerScript { AppTick = 4 CommsTick = 4 condition = DEPLOY = true event = var=REGION, val="west", time=90 event = var=REGION, val="east", time=180 reset_max = nolimit reset_time = all-posted } \end{fileverb} \vspace{0.1in} \noindent The end result when properly working should look like below. Note, at every 90 seconds, the vehicle toggles between the East and the West regions. \begin{figure}[H] \centering \includegraphics[width=0.84\textwidth]{figures/s4_alpha.png} \caption{The \var{s4\_alpha} mission in final working state.} \label{fig_s4_alpha} \gif{figures/s4_alpha.gif} \end{figure} %====================================================================== \newpage \subsection{Exercise 4 - Integrate the iSay App to Behavior Events} \label{sec_s5} In this exercise the goal is to further modify the previous Alpha mission to generate audio events when the vehicle completes surveying in either region. Audio events will be generated with the \app{iSay} MOOS App. \vspace{0.1in} \noindent You will need to do the following steps: \begin{packed_itemize} \item Copy the \var{s2\_alpha} mission, naming it \var{s5\_alpha} \item Add \app{iSay} to the list of apps launched in the mission, inside the Antler configuration block of alpha.moos. \item Configure \app{iSay} with its default configuration block and add it to alpha.moos. \item Download to audio files \var{shipbell.wav}, and \var{buzzer.wav} from the MIT server. \vspace{0.1in} \begin{consoleverb} $ wget http://oceanai.mit.edu/pavlab/txt/shipbell.wav $ wget http://oceanai.mit.edu/pavlab/txt/buzzer.wav \end{consoleverb} \vspace{0.1in} \item Configure the east survery mission to sound the shipbell sound upon completion. \item Configure the west survery mission to sound the buzzer sound upon completion. \end{packed_itemize} \vspace{0.1in} \noindent The \app{iSay} documentation can be found here: \vspace{0.1in} \urlx{http://oceanai.mit.edu/ivpman/apps/iSay} \vspace{0.1in} \noindent You will need to add an iSay event as an endflag for each behavior. For example: \begin{fileverb} //-------------------------------------- Behavior = BHV_Waypoint { name = east_waypt_survey pwt = 100 condition = RETURN = false condition = DEPLOY = true condition = REGION = east endflag = REGION = west endflag = SAY_MOOS = file=shipbell.wav . . . } \end{fileverb} \vspace{0.1in} \noindent And: \begin{fileverb} //-------------------------------------- Behavior = BHV_Waypoint { name = west_waypt_survey pwt = 100 condition = RETURN = false condition = DEPLOY = true condition = REGION = east endflag = REGION = west endflag = SAY_MOOS = file=buzzer.wav . . . } \end{fileverb} %====================================================================== \newpage \subsection{Exercise 5 - Station Keeping at Waypoints} \label{sec_s6} In this exercise the goal is to modify the original Alpha mission to station-keep each time it arrives at one of its waypoints. The user then re-clicks the DEPLOY button in \app{pMarineViewer} to send the vehicle in motion again. \vspace{0.1in} \noindent You will need to do the following steps: \begin{packed_itemize} \item Copy the \var{s1\_alpha} mission, naming it \var{s6\_alpha} \item Add a StationKeep behavior to the behavior file. \item Add a wptflag configuration to the Waypoint behavior, such that it turns {\em off} the Waypoint behavior, and turns {\em on} the StationKeeping behavior. \item Modify the \app{pMarineViewer} DEPLOY button such that it also turns off StationKeeping when it is clicked. \end{packed_itemize} \vspace{0.1in} \noindent The end result when properly working should look like below. Note the buttons and the button pushes by the user. \begin{figure}[H] \centering \includegraphics[width=0.88\textwidth]{figures/s6_alpha.png} \caption{The \var{s6\_alpha} mission in final working state.} \label{fig_s6_alpha} \gif{figures/s6_alpha.gif} \end{figure} %====================================================================== \newpage \subsection{Exercise 6 - Station Keeping at Waypoints, for Fixed Durations} \label{sec_s7} In this exercise the goal is to modify the previous Alpha mission, which will station-keep each time it arrives at one of its waypoints, to automatically resume its deployment after a short period of time. No user involvement required. \vspace{0.1in} \noindent You will need to do the following steps: \begin{packed_itemize} \item Copy the \var{s6\_alpha} mission, naming it \var{s7\_alpha} \item Modify the StationKeep behavior to have a duration. \item Add an endflag to the StationKeep behavior such that it shuts itself off after the duration expires. \item Declare the StationKeep behavior to be perpetual - so that it can be used again after it completes. \end{packed_itemize} \vspace{0.1in} \noindent The end result when properly working should look like below. Note that no buttons are being pushed by the user. \begin{figure}[H] \centering \includegraphics[width=0.88\textwidth]{figures/s7_alpha.png} \caption{The \var{s7\_alpha} mission in final working state.} \label{fig_s7_alpha} \gif{figures/s7_alpha.gif} \end{figure} %====================================================================== \newpage \section{Where to Find the Solutions} %====================================================================== All solutions can be dowloaded from the class server (after the end of the class): \vspace{0.1in} \noindent Exercise 1: \begin{packed_itemize} \item \urlx{https://oceanai.mit.edu/minicourse-pisa/missions/s2\_alpha/alpha.moos} \item \urlx{https://oceanai.mit.edu/minicourse-pisa/missions/s2\_alpha/alpha.bhv} \end{packed_itemize} \vspace{0.1in} \noindent Exercise 2: \begin{packed_itemize} \item \urlx{https://oceanai.mit.edu/minicourse-pisa/missions/s3\_alpha/alpha.moos} \item \urlx{https://oceanai.mit.edu/minicourse-pisa/missions/s3\_alpha/alpha.bhv} \end{packed_itemize} \vspace{0.1in} \noindent Exercise 3: \begin{packed_itemize} \item \urlx{https://oceanai.mit.edu/minicourse-pisa/missions/s4\_alpha/alpha.moos} \item \urlx{https://oceanai.mit.edu/minicourse-pisa/missions/s4\_alpha/alpha.bhv} \end{packed_itemize} \vspace{0.1in} \noindent Exercise 4: \begin{packed_itemize} \item \urlx{https://oceanai.mit.edu/minicourse-pisa/missions/s5\_alpha/alpha.moos} \item \urlx{https://oceanai.mit.edu/minicourse-pisa/missions/s5\_alpha/alpha.bhv} \end{packed_itemize} \vspace{0.1in} \noindent Exercise 5: \begin{packed_itemize} \item \urlx{https://oceanai.mit.edu/minicourse-pisa/missions/s6\_alpha/alpha.moos} \item \urlx{https://oceanai.mit.edu/minicourse-pisa/missions/s6\_alpha/alpha.bhv} \end{packed_itemize} \vspace{0.1in} \noindent Exercise 6: \begin{packed_itemize} \item \urlx{https://oceanai.mit.edu/minicourse-pisa/missions/s7\_alpha/alpha.moos} \item \urlx{https://oceanai.mit.edu/minicourse-pisa/missions/s7\_alpha/alpha.bhv} \end{packed_itemize} \end{document}