<?xml version="1.0" encoding="UTF-8"?>
<Mission xmlns="Tethys"
       xmlns:Control="Tethys/Control"
       xmlns:Guidance="Tethys/Guidance" 
       xmlns:Units="Tethys/Units"
       xmlns:Universal="Tethys/Universal"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="Tethys http://okeanids.mbari.org/tethys/Xml/Tethys.xsd
                           Tethys/Control http://okeanids.mbari.org/tethys/Xml/Control.xsd
                           Tethys/Guidance http://okeanids.mbari.org/tethys/Xml/Guidance.xsd
                           Tethys/Units http://okeanids.mbari.org/tethys/Xml/Units.xsd
                           Tethys/Universal http://okeanids.mbari.org/tethys/Xml/Universal.xsd"
       Id="mind_the_drift">

    <Description>
        This mission drifts level at a depth while running the backseat and
        sending acomms data. Originally it was written for the Big Business of
        getting ayeris images transferred over the acomms link. The Drift: You
        start sinking, better grab an oar and row. And please take a path that
        you know You start thinking, making up the images as you go, as you go.
    </Description>

    <DefineArg Name="MissionTimeout"><Description>
        Maximum duration of mission
    </Description><Units:minute/><Value>120</Value></DefineArg>

    <DefineArg Name="NeedCommsTime"><Description>
        How often to surface for commumications
    </Description><Units:minute/><Value>60</Value></DefineArg>

    <DefineArg Name="AcousticModemCommsInterval"><Description>
        How often to trigger acoustic modem communications
    </Description><Units:minute/><Value>5</Value></DefineArg>
        
    <DefineArg Name="Depth"><Description>
        How deep to drift.
    </Description><Units:meter/><Value>35</Value></DefineArg>

    <DefineArg Name="DepthDeadband"><Description>
        How much vertical drift from the specified depth is allowed durnig the
        mission.
    </Description><Units:meter/><Value>1</Value></DefineArg>

    <DefineArg Name="ApproachSpeed"><Description>
        Enables vehicle thruster at the commanded speed to reach target depth
        (set to 0 m/s to drift).
    </Description><Units:meter_per_second/><Value>1</Value></DefineArg>

    <DefineArg Name="ApproachDepthTimeout"><Description>
        Maximum wait time for the vehicle to reach the targeted depth.
    </Description><Units:minute/><Value>20</Value></DefineArg>

    <DefineArg Name="ApproachPitchLimit"><Description>
        Max vehicle pitch (+/-) when decending from the surface.
    </Description><Units:degree/><Value>20</Value></DefineArg>

    <DefineArg Name="SurfaceThreshold"><Description>
        Surface threshold depth.
    </Description><Units:meter/><Value>2.5</Value></DefineArg>

    <DefineArg Name="MinAltitude"><Units:meter/><Value>5</Value></DefineArg>

    <DefineArg Name="MaxDepth"><Units:meter/><Value>52</Value></DefineArg>

    <DefineArg Name="MinOffshore"><Units:kilometer/><Value>2</Value></DefineArg>

    <DefineArg Name="CheckDepths"><Units:bool/><Value>1</Value></DefineArg>

    <Timeout Duration="MissionTimeout"/>

    <Insert Filename="Insert/Science.xml"/>

    <Insert Filename="Insert/NeedComms.xml" Id="NeedComms"/>

    <Assign><Sequence/><Arg Name="NeedComms:DiveInterval"/><Arg Name="NeedCommsTime"/></Assign>

    <Insert Filename="Insert/StandardEnvelopes.xml"/>

    <Assign><Sequence/><Arg Name="StandardEnvelopes:MinAltitude"/><Arg Name="MinAltitude"/></Assign>

    <Assign><Sequence/><Arg Name="StandardEnvelopes:MaxDepth"/><Arg Name="MaxDepth"/></Assign>

    <Assign><Sequence/><Arg Name="StandardEnvelopes:MinOffshore"/><Arg Name="MinOffshore"/></Assign>


    <Insert Filename="Insert/AcousticModemComms.xml" Id="AcousticComms">
        <RedefineArg Name="CommsInterval"><Arg Name="AcousticModemCommsInterval"/></RedefineArg>
    </Insert>

    <Aggregate Id="CheckTargetDepths">

        <Sequence/>

        <Break>
            <Not><Arg Name="CheckDepths"/></Not>
        </Break>

        <Aggregate Id="CheckDepth">

            <Sequence/>

            <Break>
                <Not><Arg Name="Depth"/><Gt><Arg Name="MaxDepth"/></Gt></Not>
            </Break>

            <Syslog Severity="Important">Aborting mission. Target depth exceeds the mission's MaxDepth setting (review mission parameters).</Syslog>

            <Guidance:Execute>
                <Sequence/>
                <Setting><Guidance:Execute.command/><String>stop</String></Setting>
            </Guidance:Execute>

        </Aggregate>

        <Assign><Sequence/><Arg Name="CheckDepths"/><Units:bool/><Value>0</Value></Assign>

    </Aggregate>

    <Call Id="StartingMission" RefId="NeedComms"/>

    <Syslog>Powering up backseat...</Syslog>

    <Guidance:BackseatDriver>
        <Parallel/>
    </Guidance:BackseatDriver>

    <Syslog>Backseat powered.</Syslog>

    <Aggregate Id="TheDrift">

        <Sequence/>

        <Break>
            <IsNaN><Arg Name="Depth"/>
            </IsNaN>
        </Break>

        <Assign><Parallel/><Control:VerticalControl.kpPitchMass/><Units:ratio/><Value>0.005</Value></Assign>

        <Assign><Parallel/><Control:VerticalControl.kiPitchMass/><Units:reciprocal_second/><Value>0.00075</Value></Assign>

        <Assign><Parallel/><Control:VerticalControl.kdPitchMass/><Units:second/><Value>0</Value></Assign>

        <Assign><Parallel/><Control:VerticalControl.depthDeadband/><Arg Name="DepthDeadband"/></Assign>

<!--     DO NOT REMOVE the syslog entry below. The MissionManager seems to ignore the value of ApproachSpeed and does not evaluate the SetSpeed statement properly. Adding the syslog call somehow fixes it. -->

        <Syslog Severity="Info">Going to target depth. Speed set to <Arg Name="ApproachSpeed"/><Units:meter_per_second/></Syslog>

        <Aggregate Id="GoToTargetDepth">

            <Assign><Parallel/><Control:VerticalControl.pitchLimit/><Arg Name="ApproachPitchLimit"/></Assign>

            <Aggregate Id="ActuatorHold">

                <Description>
                    Hold the positions of the mass, VBS, and rudder while going
                    to the target depth with the thruster on.
                </Description>

                <While>
                    <Arg Name="ApproachSpeed"/>
                    <Gt><Units:meter_per_second/><Value>0</Value></Gt>
                </While>

                <Guidance:Point>
                    <Parallel/>
                    <Setting><Guidance:Point.rudderAngle/><Units:degree/><Value>13</Value></Setting>
                </Guidance:Point>

                <Guidance:Buoyancy>
                    <Parallel/>
                    <Setting><Guidance:Buoyancy.position/><Control:VerticalControl.buoyancyNeutral/></Setting>
                </Guidance:Buoyancy>

                <Guidance:Pitch>
                    <Parallel/>
                    <Setting><Guidance:Pitch.massPosition/><Control:VerticalControl.massDefault/></Setting>
                </Guidance:Pitch>

            </Aggregate>

            <Aggregate Id="ApproachDepth">

                <Sequence/>

                <Syslog>Moving to <Arg Name="Depth"/><Units:meter/></Syslog>

                <Guidance:SetSpeed>
                    <Parallel/>
                    <Setting><Guidance:SetSpeed.speed/><Arg Name="ApproachSpeed"/></Setting>
                </Guidance:SetSpeed>

                <Guidance:Pitch>
                    <Sequence/>
                    <Timeout Duration="ApproachDepthTimeout">
                        <Syslog Severity="Important">Timed out trying to reach the target depth. Stopping mission at current depth of <Universal:depth/><Units:meter/></Syslog>
                        <Guidance:Execute>
                            <Sequence/>
                            <Setting><Guidance:Execute.command/><String>stop</String></Setting>
                        </Guidance:Execute>
                    </Timeout>
                    <Setting><Guidance:Pitch.depth/><Arg Name="Depth"/></Setting>
                </Guidance:Pitch>

            </Aggregate>

        </Aggregate>

        <Aggregate Id="DriftAtDepth">

            <Description>
                Drift at 0 speed at target depth.
            </Description>

            <Sequence/>

            <Assign><Parallel/><Control:VerticalControl.depthDeadband/><Arg Name="DepthDeadband"/></Assign>

            <Guidance:SetSpeed>
                <Parallel/>
                <Setting><Guidance:SetSpeed.speed/><Units:meter_per_second/><Value>0</Value></Setting>
            </Guidance:SetSpeed>

            <Guidance:Pitch>
                <Parallel/>
                <Setting><Guidance:Pitch.depth/><Arg Name="Depth"/></Setting>
                <Setting><Guidance:Pitch.elevatorAngle/><Units:degree/><Value>0</Value></Setting>
                <Setting><Guidance:Pitch.pitch/><Units:degree/><Value>0</Value></Setting>
            </Guidance:Pitch>

            <Syslog Severity="Info">Holding at depth. Depth = <Universal:depth/><Units:meter/></Syslog>

            <Guidance:Wait>
                <Sequence/>
                <Setting><Guidance:Wait.duration/><Arg Name="MissionTimeout"/></Setting>
            </Guidance:Wait>

        </Aggregate>

    </Aggregate>

</Mission>
