# Lecture 11

### video segment:


* Below arm is 6DOF and can carry 80 kg.
### Joint space dynamics:

* what is mass matrix and kinetic energy matrix?
* how to calculate kinematic energy matrix?
* Below M(q) is not mass matrix - kinectic energy matrix it is actually mass matrix or kinematic energy matrix.
* $\Gamma$ will be like ${\Gamma}_1\,{\Gamma}_2$ to q1,q2...
*


* What is this second Ni equation ? what is cenrifugal coriolis force ?
* To eliminate internal forces we will find component about joint axes.
* from kinetic energy equation we will find M , and with potencial enrgy we will find G, and if have M we will find V.
*


* i didn't understood below equation of $\tau$ and also of ni?

### Newton -Euler algoritm
* it propogates velocities,accelerations and intertial forces to end effector and back propogates (i.e, taking projection of these forces on axes ) and when we reach the ground we get torques ?


* inertia tensor?
* here we are looking at force equations for a particle and then we will extend it to the n particles.
*


* in context of rigid body
* here we are again using cross product operator
* so the whole integral is intertia tensor
*


* Didn't understood the equation of N (moment)
* we need to find $I$ of each of the rigid body of our robot.
*


* now we have got inertia tensor
* well in parallel axis we are finding inertia about outer axis A with below given formula.
*


* what does he mean of products of inertia?


* Didn't understood the second equation of rotational motion?


* here we have found linear acceleration but we also need to find velocity and acceleration at COM





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* here we have ignored G .