Module: scanningInstrumentController
Executive Summary
Module to perform continuous instrument control if attitude error and attitude rate are within specified tolerances. If within the specified tolerances, the module will send an imaging command to the instrument. Applicable use case could be a continuous nadir imaging (scanning), where it must constantly check for attitude requirements.
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 |
|---|---|---|
accessInMsg |
Ground location access input message |
|
attGuidInMsg |
Attitude guidance input message |
|
deviceStatusInMsg |
(optional) Device status input message |
|
deviceCmdOutMsg |
Device status command output message |
Detailed Module Description
This module writes out a DeviceCmdMsgPayload to turn on an instrument, i.e. Module: simpleInstrument, continuously while the requirement conditions are met.
The module first checks if the instrument controller is active using the controllerStatus variable. This variable
defaults to 0 (inactive) due to swig initialization of the module, but the user may set the variable to 1 (active)
with the deviceStatusInMsg or controllerStatus variable. If the instrument controller is active, the module
then checks if the norm of the attitude error is less than the user specified tolerance and if the Module: groundLocation
is accessible. If both are true, the module sets the deviceCmd to 1. Otherwise, the deviceCmd is set to 0.
User Guide
Two variables must be set, attErrTolerance and useRateTolerance. The variable attErrTolerance is the norm
of the acceptable attitude error in MRPs; It must be set at the beginning of the sim. Also, useRateTolerance must
be set to specify if the module should check for attitude rate requirements (set useRateTolerance to 1 to check,
otherwise set to 0).
If useRateTolerance is set to 1, rateErrTolerance must be set to the norm of the acceptable attitude rate
in rad/s. Otherwise, if useRateTolerance is set to 0, rateErrTolerance is not used.
If the user desires to make the instrument controller inactive, the controllerStatus variable should be set to 0.
This may be done if the controller is to match the status of corresponding instrument data and power modules. This
may also be accomplished by writing out a DeviceStatusMsgPayload to the deviceStatusInMsg.
Functions
-
void SelfInit_scanningInstrumentController(scanningInstrumentControllerConfig *configData, int64_t moduleID)
This method initializes the output messages for this module.
- Parameters:
configData – The configuration data associated with this module
moduleID – The module identifier
- Returns:
void
-
void Update_scanningInstrumentController(scanningInstrumentControllerConfig *configData, uint64_t callTime, int64_t moduleID)
This method checks the status of the device and if there is access to target, as well if the magnitude of the attitude error and attitude rate are within the tolerance. If so, the instrument is turned on, otherwise it is turned off.
- Parameters:
configData – The configuration data associated with the module
callTime – The clock time at which the function was called (nanoseconds)
moduleID – The module identifier
- Returns:
void
-
void Reset_scanningInstrumentController(scanningInstrumentControllerConfig *configData, uint64_t callTime, int64_t moduleID)
This method checks if required input messages (accessInMsg and attGuidInMsg) are connected.
- Parameters:
configData – The configuration data associated with the module
callTime – [ns] time the method is called
moduleID – The module identifier
- Returns:
void
-
struct scanningInstrumentControllerConfig
- #include <scanningInstrumentController.h>
Module to perform continuous instrument control.
Public Members
-
double attErrTolerance
Normalized MRP attitude error tolerance.
-
unsigned int useRateTolerance
Flag to enable rate error tolerance.
-
double rateErrTolerance
Rate error tolerance in rad/s.
-
unsigned int controllerStatus
dictates whether or not the controller should be running
-
AccessMsg_C accessInMsg
Ground location access.
-
AttGuidMsg_C attGuidInMsg
Attitude guidance input message.
-
DeviceStatusMsg_C deviceStatusInMsg
Device status input message.
-
DeviceCmdMsg_C deviceCmdOutMsg
Device status output message.
-
BSKLogger *bskLogger
BSK Logging.
-
double attErrTolerance