Sensor Fusion Block

To create a block that runs using the sensor fusion code already in the ZP3.5 code base, a C function. More about them can be read here: https://www.mathworks.com/help/simulink/slref/cfunction.html?s_tid=mwa_osa_a, (there is also a link to youtube guide at the bottom of this page). This was also paired with some modification to the C++ code, such that the data that was previously retrieved through instances of the various sensors’ drivers, is now passed into the function.

Moreover, when talking about “the function” this refers to the ‘SF_GenerateNewResult’ function in the ZP3.5 sensor fusion code, as this is the block we care about.

Simulink Block Inputs & Outputs:

Note that all data types are automatically generated as Simulink.Bus types based on the struct definitions in the code. Within each struct however, each data type essentially gets translated to the equivalent data type in MATLAB.

Inputs:

• imuData

  • Input for IMU data readings into sensor fusion block.

  • Of type IMU_Data_t.

• GpsData

  • Input for GPS data readings into sensor fusion block.

  • Of type Gps_Data_t.

• altimeterData

  • Input for altimeter data readings into sensor fusion block.

  • Of type Altimeter_Data_t.

• iterData

  • Input for the values stored between iterations.

  • Of type SFIterationData_t.

• SFoutput

  • Doesn’t need an input, just used so that an output can be created for this (I believe).

  • Of type SFOutput_t.

• twoKi

  • Input for Ki constant for MahonyAHRS.

  • Of type single (equivalent to float).

• twoKp

  • Input for Kp constant for MahonyAHRS.

  • Of type single (equivalent to float).

Outputs:

• out

  • Can be ignored (created because of input)

• imuData

  • Can be ignored (created because of input)

• GpsData

  • Can be ignored (created because of input)

• altimeterData

  • Can be ignored (created because of input)

• iterData

  • Output of the changed iteration data.

  • Of type SFIterationData_t.

• SFoutput

  • Output of the sensor fusion block (all the estimated values)

  • Of type SFOutput_t

Errors List (will keep expanding on it):

(From the errors I still remember while documenting this)

• Compilation errors:

  • Had trouble with extern C functions being called from the sensor fusion c++ file. This was just fixed by moving these functions into the sensor fusion file and it seemed to work. (Still not fully sure what the issue was).

• Simulink runtime errors:

  • Had issues running the Simulink model with the block imported using the Code importer wizard, but now works fine when importing the code using a c function block.

  • “’Sensor_Fusion_ZP.sldd’ was not found” error on running Simulink model. This can occur when opening the project for the first time or when reopening it, and can be fixed by relinking the Sensor Fusion data dictionary file (’Sensor_Fusion_ZP.sldd’).

  This can be done through the model explorer, which can be accessed from the bottom left corner of the Simulink window (picture of the symbol attached below).
  

  

Testing

Will document testing procedure and how it goes here.

How to create a C Function Block