In previous section, we have learned how to generate trajectory for the robotic manipulators.
And this was pretty interesting actually how we didn't learn trajectory planning in order to plan and
plot them and look how beautiful they are.
This is not a drawing lesson.
We have learned them in order to do trajectory planning and then make a robot manipulator to track these
trajectories.
We have seen the first part, namely trajectory planning.
Now it's time to learn how to do the second part.
Namely, in this second part, we will riot control algorithms in order to make robot manipulator track
to give trajectory with as small errors as possible, ideally zero.
So before going on, let's see some terminologies.
First of all, we can categorize controller into controllers in two ways.
The centralized control algorithms and centralized ones.
The difference between them is the centralized control algorithms take each one as individual and try
to control it separately and accept more minorities and couplings in robot dynamics as disturbances.
And they are tried to be rejected.
This assumption can be accepted under low velocities.
However, as the velocity increases, the coupling effects in robot dynamics increases in that level
that it cannot be taken as a disturbance to be rejected.
Indeed, there has to be some method to handle them at this moment.
Centralized control methods come to the help.
They don't take each joint individually but try to provide control to the whole robot together, so
it takes into account more minorities and the couplings in robot dynamic model.
Because of that, centralized metal, centralized control methods are superior.
However, as we will see in the future, these methods will also not solve the problem completely.
This is because while they are considering robot dynamics model non-linear this uncoupling, we assume
that we have perfect model, which models disturbances perfectly with the perfect knowledge of dynamic
parameters.
Additionally, we don't take into account external disturbances that affect the robot manipulator.
All these factors will affect the stability of the robot control algorithm, which we will see in future
lessons.
In order to solve these issues, we will introduce advanced control algorithms such as robust control
and adaptive control method.
They will take into account external disturbances and uncertainties in the knowledge of dynamic parameters.
Robust control will try to reject disturbances and parameter uncertainties with high energy input,
while adaptive control will accept disturbances as changes in model dynamic parameters and so control
parameters.
So control parameters will be adapted based on these changes.
So without further ado, let's jump into the robot control methods.