<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">%=====================================================================
\section{The GoToDepth Behavior}
%=====================================================================
\wikisec{grp=bhvsolo, file=BehaviorGoToDepth,short=GoToDepth Behavior}
\label{bhv_gotodepth}
\index{IvP Behaviors Implemented!\var{BHV\_GoToDepth}}
\index{GoToDepth Behavior}

This behavior will drive the vehicle to a sequence of specified depths
and duration at each depth.  This behavior merely expresses a
preference for a particular depth. If other behaviors also have a
depth preference, coordination/compromise will take place through the
multi-objective optimization process. A log of vehicle depth similar
to figure below may result.

\begin{figure}[H]
  \centering 
  \includegraphics[width=1.0\textwidth]{figs_bhvs/goto_depth.png}
  \caption{Depth log from simulation with the depth parameters shown
    in Listing \ref{lst_gotodepth_block}. The lighter, step-like line
    indicates the values of \mvar{DESIRED\_DEPTH} generated by the
    helm, and the darker line indicates the recorded depth value of
    the vehicle. The depth plateaus start from the moment the vehicle
    achieves depth. For example, the vehicle achieved a depth of 45
    meters at 119 seconds and retained that desired depth for another
    60 seconds as requested in the configuration shown in Listing
    \ref{lst_gotodepth_block}.}
  \label{goto_depth_fig}
\end{figure}
\vspace{0.11in}


%=======================================================================
\subsection{Configuration Parameters}

\input{includes/bhv_all_properties}

\vspace{0.15in}
\begin{listing}{Configuration Parameters for the GoToDepth Behavior}
\label{lst_bhv_gotodepth}
\small
\renewcommand{\arraystretch}{1.15}
\begin{longtable}{rp{0.76\textwidth}} 

  {\bf Parameter} &amp; {\bf Description} \\  

  \bvar{capture\_delta} &amp; The delta depth, in meters, between the
  current observed depth and the current target depth, below which the
  behavior will declare the depth to have been achieved. The default
  value is 1 meter. Section \ref{sec_gtd_param_capture_delta}. \\

  \bvar{capture\_flag} &amp; The name of a MOOS variable incremented each
  time a target depth level has been achieved. Section
  \ref{sec_gtd_param_capture_flag}. \\

  \bvar{depth} &amp; A colon-separated list of comma-separated pairs. Each
  pair contains a desired depth and a duration at that depth. Section
  \ref{sec_gtd_param_depth}. \\

  \bvar{repeat} &amp; The number of times the vehicle will traverse
  through the evolution of depths. Section
  \ref{sec_gtd_param_repeat}. \\

\end{longtable}
\end{listing}
\normalsize

\vspace{0.15in}
\begin{listing}{Example Configuration Block}
\label{lst_gotodepth_block}

\begin{fileverb}
Behavior = BHV_GoToDepth
{
  // General Behavior Parameters
  // ---------------------------
  name         = gotodepth                 // example
  pwt          = 100                       // default
  condition    = MODE==Alpha               // example
  updates      = GOTO_DEPTH_UPDATES        // example

  // Parameters specific to this behavior
  // ------------------------------------
    capture_delta = 1                      // default (meters)
     capture_flag = DEPTH_ACHIEVED         // example
            depth = 40,60:30,45:20,45      // example
           repeat = 0                      // default
}
\end{fileverb}
\end{listing}



%=======================================================================
\subsection{A Detailed Discussion of GoToDepth Behavior Parameters}

%-----------------------------------------------------------------------
\subsubsection{The \bvar{capture\_flag} Parameter}
\label{sec_gtd_param_capture_flag}

This parameter names a MOOS variable incremented each time a target
depth level has been achieved. It may be useful for logfile analysis
and also allows other behaviors to be conditioned on a depth event. If
this behavior is completed in {\em perpetual} mode, the counter is
reset to zero. If the behavior is repeating a set of depths by setting
\bvar{repeat} greater than zero, the counter will continue to
increment through evolutions. The default value is the empty string,
meaning nothing will be posted. Note the named MOOS variable will
automatically have the prefix \mvar{"GTD\_"} applied. 

%-----------------------------------------------------------------------
\subsubsection{The \bvar{capture\_delta} Parameter}
\label{sec_gtd_param_capture_delta}

When the GoToDepth behavior is running and actively influencing the
depth of the vehicle to a target depth level, it monitors the
discrepancy between the obvserved depth and the current target depth.
The \bvar{capture\_delta} parameter is the delta depth, in meters,
below which the behavior will declare the depth to have been
achieved. The default value is 1 meter. 

\pskip

As an example, consider a target depth of say 100 meters, and a
\bvar{capture\_delta} of 5. When a diving vehicle reaches 95 meters,
it will consider the depth achieved. However, it will continue to
influence the vehicle to a depth of 100 meters for as a long as
prescribed by the \bvar{depth} setting. The "achieving" of the depth
results in two things: (a) the duration clock for time spent at that
depth will begin, and (b) if there is a \bvar{capture\_flag} set, this
flag will be posted by the helm to the MOOSDB.


%-----------------------------------------------------------------------
\subsubsection{The \bvar{depth} Parameter}
\label{sec_gtd_param_depth}

The \bvar{depth} parameter is a colon-separated list of
comma-separated pairs. Each pair contains a desired depth and a
duration at that depth. The duration applies from the point in time
that the depth is first achieved. If a time duration is not provided
for any pair, it defaults to zero. Thus \bsvar{depth=20} is a valid
parameter setting.

\pskip

The duration is specified in seconds and reflects the time at depth
{\em after} the vehicle has first achieved that depth, where achieving
depth is defined by the \bvar{capture\_delta} parameter. The behavior
subscribes for \mvar{NAV\_DEPTH} to examine the current vehicle depth
against the target depth. If the current depth is within the delta
given by \bvar{capture\_delta}, that depth is considered to have been
achieved. The behavior also stores the previous depth from the prior
behavior iteration, and if the target depth is between the prior depth
and current depth, the depth is considered to be achieved regardless
of whether the prior or current depth is actually within the
\bvar{capture\_delta}.

%-----------------------------------------------------------------------
\subsubsection{The \bvar{repeat} Parameter}
\label{sec_gtd_param_repeat}

The number of times the vehicle will traverse through the evolution of
depths, proceeding to the 1st depth after the nth depth has been
hit. The default value is zero. 

%-----------------------------------------------------------------------
\subsubsection{The \bvar{perpetual} Parameter}

The \bvar{perpetual} parameter is defined at the superclass level, but
it's worth discussing its function here.  If equal to true, when the
vehicle completes its evolution of depths (perhaps several evolutions
if \bvar{repeat} is non-zero), the endflags will be posted. But rather
than setting the complete variable to true and thus never receiving
any further run consideration, the behavior is reset to its initial
state. Presumably the user sets endflags that will cause the condition
flags to be not immediately satisfied, thus putting the behavior in a
state waiting again for an external event flag to be posted.  The
default value of this parameter is false.

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