Module: velocityPoint

Executive Summary

This attitude guidance module computes the velocity reference frame states.

The orbit can be any type of Keplerian motion, including circular, elliptical or hyperbolic. The module PDF Description. contains further information on this module’s function, how to run it, as well as testing.

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.

Module I/O Messages

Msg Variable Name

Msg Type

Description

attRefOutMsg

AttRefMsgPayload

attitude reference output message

transNavInMsg

NavTransMsgPayload

incoming spacecraft translational state message

celBodyInMsg

EphemerisMsgPayload

(optional )primary celestial body information input message

Functions

void SelfInit_velocityPoint(velocityPointConfig *configData, int64_t moduleID)

self init method

Parameters:

  • configData – The configuration data associated with RW null space model

  • moduleID – The ID associated with the configData

Returns:

void

void Update_velocityPoint(velocityPointConfig *configData, uint64_t callTime, int64_t moduleID)

This method creates a orbit velocity frame reference message. The desired orientation is defined within the module.

Parameters:

  • configData – The configuration data associated with the null space control

  • callTime – The clock time at which the function was called (nanoseconds)

  • moduleID – The ID associated with the configData

Returns:

void

void Reset_velocityPoint(velocityPointConfig *configData, uint64_t callTime, int64_t moduleID)

This method performs the module reset capability. This module has no actions.

Parameters:

  • configData – The configuration data associated with this module

  • callTime – The clock time at which the function was called (nanoseconds)

  • moduleID – The ID associated with the configData

Returns:

void

void computeVelocityPointingReference(velocityPointConfig *configData, double r_BN_N[3], double v_BN_N[3], double celBdyPositonVector[3], double celBdyVelocityVector[3], AttRefMsgPayload *attRefOut)
struct velocityPointConfig
#include <velocityPoint.h>

Data structure for module to compute the orbital velocity spinning pointing navigation solution.

Public Members

double mu

Planet gravitational parameter.

AttRefMsg_C attRefOutMsg

The name of the output message.

NavTransMsg_C transNavInMsg

The name of the incoming attitude command.

EphemerisMsg_C celBodyInMsg

The name of the celestial body message.

int planetMsgIsLinked

flag if the planet message is linked

BSKLogger *bskLogger

BSK Logging.