How to understand "Total torque" acting on a revolute joint ?

Hi, everyone.

I have trouble understanding the meaning of "Total torque".

In double pendulum (multi-body 2nd generation, Matlab) under gravity, when I tried to check the value of torque acting on the first revolute joint, there's 3 components. https://jp.mathworks.com/examples/simmechanics/mw/sm_product-sm_double_pendulum-assembling-parts-into-a-double-pendulum

I'd like to know the the torque around y axis as shown in this Figure... I think "tty" means the "τ" that I'd like to check... am I right ?

Answer 1

[Steve Miller]

The total torque acting at a joint includes contributions from actuation, constraint, and internal torques. For an explanation of those terms, look at this documentation page which explains them in detail.

https://www.mathworks.com/help/physmod/sm/ug/sense-forces-and-torques-at-joints.html

--Steve