How to get collective thrust in practice?

[cmakelabs]

I would like to know, how in practice one can get commanded collective thrust, force measurements?
How can I try VID-Fusion on a real quadrotor? In simulation it might be possible to have a topic that provides the collective thrust and forces, but in reality how could one get them?

I would be really grateful for your elaborate answer

[zmdingnav]

Hello! At the III-C Thrust Coefficient Identification section in VID-Fusion: Robust Visual-Inertial-Dynamics Odometry for Accurate External Force Estimation, we describe our way to get the Thrust Coefficient with a simple method which we control the quadrotor keep hovering to collect rotor speed $\omega_{i}$ by peoposed RMU. And then, we can calculate the Thrust Coefficient $(\tau_{f_i})$ for each rotor by ${T}^{b_i} = \tau_{f_i} \omega_{i}^2 = \frac{mg}{4}$ with known weight $m$. Thus, we can get commanded collective thrust ${T}^{b}$ by $\mathbf{T}^b = \frac{1}{m}\sum_{i=1}^{4}\big(\tau_{f_i} \omega_{i}^2)$. Thanks!