Hi all,
I am a university student interested in systems engineering / new to the EA software and wanted to ask if what I am trying to achieve would be possible with this tool (currently using the trial version). I am looking into making use of EA for Model Based Systems Engineering (MBSE), namely behaviour modelling, using SysML. I have previously been able to use Cameo Systems Modeler successfully for a similar task. However, I have found it difficult to find comprehensive tutorials / webinars / documentation to help with developing in EA.
The model I envision can be broken down into several aspects, I will try to explain them concisely.
Firstly, the system I am looking to model (a small CubeSat satellite) would be made up of a simple architectural model that breaks the system into a few high level subsystem components (payload, power control unit, antennas, thermal control etc.) – first picture
<img src="
https://i.ibb.co/7GkZ054/EA.png" alt="EA" border="0">
Secondly, the system can be in a variety of states to reflect the various operating phases of the satellite during nominal operations (carrying out scientific ops, communicating with ground station etc.). The various subsystems would then have their own individual states to reflect the different modes that they are placed in during the various phases of the mission (i.e. the antenna is only powered on during communications with the ground station) – second and third picture
<img src="
https://i.ibb.co/hXjRXm4/Sat-Modes.png" alt="Sat-Modes" border="0">
<img src="
https://i.ibb.co/m9WzvgN/XBand.png" alt="XBand" border="0">
The end goal of this would be to create a model that makes it possible to monitor the current state of the system and relate this to the states of the various subsystems to aid in explaining the mission Concept of Operations (ConOps). I also hope to potentially be able to monitor power consumption depending on the state of the system (i.e. if “x” components are powered-on, then the overall power consumption will be “y”) by allocating “power” property values to the various subsystem architectural blocks and states.
When previously attempting this modelling exercise in Cameo System Modeller, I achieved this from a combination of Activity, StateMachine, BDD and IBD diagrams. The StateMachine was made from the various modes the satellite could be in, with transitions between each mode. The transitions were triggered by the reception of signals. When the overall satellite transitioned between high level modes, it would cause entryBehavior that then sent further signals to trigger the subsystems to change their respective modes – fourth picture
<img src="
https://i.ibb.co/L8Rr8WT/Modes.png" alt="Modes" border="0">
These signals were generated by an activity diagram that read in data from an external Excel file line by line – fifth picture
<img src="
https://i.ibb.co/WNhQCrX/Excel-SIm.png" alt="Excel-SIm" border="0">
The data from the Excel file related to the order in which the mode transition signals would be sent, which data value corresponded to which transition signal (i.e. the value “2” led to the “PowerOn” signal being sent) , and the associated duration (to calculate the power consumption during a mode) – sixth picture
<img src="
https://i.ibb.co/PNc13xV/Excel.png" alt="Excel" border="0">
The overall model was contained in a high-level BDD to allow the necessary proxy ports to be created between the segments of the model to allow Value Properties and Signals to be carried between the various blocks using ports and IBDs – seventh and eighth picture
<img src="
https://i.ibb.co/rt4GXpK/Overall.png" alt="Overall" border="0">
<img src="
https://i.ibb.co/TWmzDBg/IBD.png" alt="IBD" border="0">
There are several aspects I am having trouble with:
• Running multiple StateMachine / Activity diagrams at once - in Cameo System Modeler I was able to simulate several diagrams at the same time, but in EA I can only seem to have a single StateMachine or Activity diagram “running” at a given time, so I can’t properly model the overall behaviour of the system in real time
• Sending signals between blocks – as I am using signals to trigger the state transitions, I need the signals to act on the relevant ports in the block IBDs so that they are received by the relevant StateMachine diagram, however, the manner in which this is achieved in EA appears to be different to Cameo Systems Modeller, and I can’t seem to find a resource that explains this comprehensively
• Reading the external data from the Excel file – Cameo Systems Modeler allowed data to be extracted line by line relatively easily using an Excel Import Profile, however I am struggling to find any such functionality or profile for EA
Apologies for the long post, but I wanted to ask if anyone might be able to give me some guidance of the feasibility of what I am hoping to achieve, and if I could get some advice / direction to resources to help with my modelling efforts.
I have tried to include all appropriate information, but I am still very new to using EA so please ask if I need to clarify anything.
Thanks!!
