Module: attTrackingError¶
Executive Summary¶
This module is intended to be the last module in the guidance module chain. It’s input is the reference motion message generated by a prior module. It’s output is at the guidance attitude tracking errors relative to a moving reference frame. This module applies the body to corrected body attitude correction. 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.
Msg Variable Name |
Msg Type |
Description |
---|---|---|
attGuidOutMsg |
attitude guidance output message |
|
attNavInMsg |
attitude navigation input message |
|
attRefInMsg |
attitude reference input message |
Functions
-
void SelfInit_attTrackingError(attTrackingErrorConfig *configData, int64_t moduleID)¶
This method initializes the configData for this module. It checks to ensure that the inputs are sane and then creates the output message
- Parameters
configData – The configuration data associated with the attitude tracking error module
moduleID – The ID associated with the configData
- Returns
void
-
void Update_attTrackingError(attTrackingErrorConfig *configData, uint64_t callTime, int64_t moduleID)¶
The Update method performs reads the Navigation message (containing the spacecraft attitude information), and the Reference message (containing the desired attitude). It computes the attitude error and writes it in the Guidance message.
- Parameters
configData – The configuration data associated with the attitude tracking error module
callTime – The clock time at which the function was called (nanoseconds)
moduleID – The Basilisk module identifier
- Returns
void
-
void Reset_attTrackingError(attTrackingErrorConfig *configData, uint64_t callTime, int64_t moduleID)¶
This method performs a complete reset of the module. Local module variables that retain time varying states between function calls are reset to their default values.
- Parameters
configData – The configuration data associated with the attitude tracking error module
callTime – The clock time at which the function was called (nanoseconds)
moduleID – The ID associated with the configData
- Returns
void
This method performs the attitude computations in order to extract the error.
- Parameters
sigma_R0R – Reference frame state
nav – The spacecraft attitude information
ref – The reference attitude
attGuidOut – Output attitude guidance message
- Returns
void
-
struct attTrackingErrorConfig¶
- #include <attTrackingError.h>
Data structure for module to compute the attitude tracking error between the spacecraft attitude and the reference.
Public Members
-
double sigma_R0R[3]¶
MRP from corrected reference frame to original reference frame R0. This is the same as [BcB] going from primary body frame B to the corrected body frame Bc.
-
AttGuidMsg_C attGuidOutMsg¶
output msg of attitude guidance
input msg measured attitude
-
AttRefMsg_C attRefInMsg¶
input msg of reference attitude
-
BSKLogger *bskLogger¶
BSK Logging.
-
double sigma_R0R[3]¶