lambertSecondDV#
Executive Summary#
This module computes the required Delta-V to change the spacecraft velocity to the desired velocity \({}^N\mathbf{v}_{desired}\) at maneuver time \(t_{maneuver}\). The desired velocity and maneuver time are obtained by the DesiredVelocityMsgPayload input message. The expected velocity \({}^N\mathbf{v}_{expected}\) at maneuver time is obtained from the second velocity in LambertSolutionMsgPayload. That is, this module computes the Delta-V that is required at the end of a Lambert problem transfer arc (at the second position vector of Lambert problem) to obtain some desired velocity. The DvBurnCmdMsgPayload output message is zeroed if the LambertSolutionMsgPayload message indicates that the Lambert solution is not valid.
Message Connection Descriptions#
The following table lists all the module input and output messages. The module msg connection is set by the user from python. The msg type contains a link to the message structure definition, while the description provides information on what this message is used for.
Msg Variable Name |
Msg Type |
Description |
|---|---|---|
lambertSolutionInMsg |
LambertSolutionMsgPayload |
lambert problem solution input message |
desiredVelocityInMsg |
DesiredVelocityMsgPayload |
desired inertial velocity input message |
dvBurnCmdOutMsg |
DvBurnCmdMsgPayload |
Delta-V command output message |
User Guide#
The module is first initialized as follows:
module = lambertSecondDV.LambertSecondDV()
module.modelTag = "lambertSecondDV"
unitTestSim.AddModelToTask(unitTaskName, module)
The input messages are then connected:
module.lambertSolutionInMsg.subscribeTo(lambertSolutionInMsg)
module.desiredVelocityInMsg.subscribeTo(desiredVelocityInMsg)
Class LambertSecondDV#
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class LambertSecondDV : public SysModel#
This module computes the second Delta-V maneuver for the Lambert problem.
Public Functions
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LambertSecondDV()#
This is the constructor for the module class. It sets default variable values and initializes the various parts of the model
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~LambertSecondDV()#
Module Destructor
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void reset(uint64_t currentSimNanos) override#
This method is used to reset the module and checks that required input messages are connected.
- Parameters:
currentSimNanos – current simulation time in nano-seconds
- Returns:
void
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void updateState(uint64_t currentSimNanos) override#
This is the main method that gets called every time the module is updated.
- Parameters:
currentSimNanos – current simulation time in nano-seconds
- Returns:
void
Public Members
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ReadFunctor<LambertSolutionMsgPayload> lambertSolutionInMsg#
lambert solution input message
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ReadFunctor<DesiredVelocityMsgPayload> desiredVelocityInMsg#
desired velocity input message
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Message<DvBurnCmdMsgPayload> dvBurnCmdOutMsg#
Delta-V burn command message.
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BSKLogger bskLogger#
— BSK Logging
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double lambertSolutionSpecifier = 1#
[-] which Lambert solution (1 or 2), if applicable, should be used
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LambertSecondDV()#