CAELUS Digital Twin

This repo consists of all components for the Digital Twin architecture (CAELUS).

Installation

The installation script install_all.sh will take care of installing all dependencies. Issue sh install_all.sh to install every dependency.

WARNING: After any change to a dependency you must re-install that dependency (for simplicityt, re-run sh install_all.sh).

GIT Workflow

This repository uses the git-subrepo package to track multiple repos. Editing a subrepo (all folders in Dependencies) and pushing it to the upstream will result in the code for that subrepo's repo to be updated.

The used subrepos are the following:

• CAELUS_SmartSkies
• CAELUS_ProbeSystem
• CAELUS_ThermalModel
• CAELUS_PowerModels

Pulling new changes

To pull all changes from all the dependencies & the main repo, issue git subrepo pull --all. One can additionally pull from a single subrepo with the command git subrepo pull Dependencies/<subrepo_name>

Pushing New Changes

To push all changes from all the dependencies & the main repo, issue git subrepo push --all. One can additionally push from a single subrepo with the command git subrepo push Dependencies/<subrepo_name>

Development

Writing startup scripts

Drone configurations

Drone configurations are stored in the available_drones folder. By default the supported vehicle types are QUADCOPTER and EVTOL_FW (This value is used across the simulation stack to determine the vehicle type).

Adding a new drone

To add a new drone configuration:

1. Add a .json file in the available_drones folder with the example specified below:

{
    "id": "evtol_fw_large",
    "name": "EVTOL FW Large",
    "px4_airframe_reference": "custom_evtolfw_large",
    "type": "EVTOL_FW",
    "px4_airframe_parameters": {
        "FW_THR_CRUISE": 0.54
    },
    "aerodynamics": {
        "wing_span": 2.1,
        "wing_area": 0.8,
        "mean_aerodynamic_chord": 0.357,
        "m_CL_0": 0.0477,
        "m_CL_alpha": 4.06,
        "m_CL_delta_e": 0.7,
        "m_CL_q": 3.87,
        "m_CD_0": 0.0107,
        "m_CD_alpha": -0.00955,
        "m_CD_alpha2": 1.1,
        "m_CD_delta_e2": 0.0196,
        "m_CD_beta2": 0,
        "m_CD_beta": 0.115,
        "m_CD_q": 0,
        "m_CS_0": 0,
        "m_CS_beta": -0.194,
        "m_CS_delta_a": 0.0439,
        "m_CS_delta_r": 0,
        "m_CS_p": -0.137,
        "m_CS_r": 0.0839,
        "m_Cm_0": 0.00439,
        "m_Cm_alpha": -0.227,
        "m_Cm_delta_e": -0.325,
        "m_Cm_q": -1.3,
        "m_Cl_0": 0,
        "m_Cl_beta": -0.0751,
        "m_Cl_delta_a": 0.202,
        "m_Cl_delta_r": 0,
        "m_Cl_p": -0.404,
        "m_Cl_r": 0.0555,
        "m_Cn_0": 0,
        "m_Cn_beta": 0.0312,
        "m_Cn_delta_a": -0.00628,
        "m_Cn_delta_r": 0,
        "m_Cn_p": 0.00437,
        "m_Cn_r": -0.012
    },
    "drone_config": {
        "mass": 2.0,
        "arm_length": 0.25,
        "max_rpm": 13000,
        "max_torque": 0.10,
        "propeller_specs": {
            "diameter_cm": 18.0,
            "pitch_cm": 13.0,
            "blades_n": 3
        },
        "drag_move": 0.028,
        "Ixx": 0.335,
        "Iyy": 0.14,
        "Izz": 0.4,
        "Ixz": -0.029,
        "Izx": -0.029
    }
}

NOTE: "px4_airframe_parameters" contains non-standard parameters for the new airframe. Dependeing on the drone type there are some defaults specified in the PX4 fork airframe files 4200_custom_quad and 4201_custom_evtol.

2. Run the sync_custom_px4_vehicles.py script: python3 sync_custom_px4_vehicles.py

The new configuration will now be available in the digital twin. See Writing startup scripts for the appropriate parameter to use.

Tooling