I mean, keys are always in the place where you expect them to be, so what is the challenge here? (Yes, too lazy to read the article).
If you know the precise state of each motor in a robot hand, you can compute the absolute position of its fingertip, right?
To make a robot play piano, you need to solve the reverse problem of it i.e. to compute the motor states from the target robot position. This problem is called "Inverse Kinematics" and not fully resolved to this day.
Reinforcement Learning (RL) people claim that, if you let a robot move randomly, and give it apporopriate rewards depending on the resulting state, eventually it learns to solve the problem by itself (just like a human baby eventually learns how to walk through trial & error).
Now, you are looking at the state of the art of RL in 2023.
IK to my knowledge is well known in every setting I am aware of.
No, a state-based RL research like this is essentially an IK problem. Given a goal position in the world frame, you need to find out the motor configuration to move your EEF to that goal position.
> IK to my knowledge is well known in every setting I am aware of.
Really? When I was working in this field, I've actually never seen anyone who used numerical/analytical IK methods on real robots.
Granted that I was not a Robotics engineer (I was a Deep Learning engineer in the team), but my impression at the time was that no practical IK solution was available for a robot with 8 DOF, let alone a 20 DOF robot like Shadow Hand.
If you provide the 6DoF trajectory (+ gripper joints), a lot of robotics (manipulation in particular) is basically solved. The problem is, we don’t have these good trajectories.
Sure, joint space is commonly used for learned policies, but cartesian space isn’t uncommon either.
IK is really just not a major focus on the learning side of robotics because it’s not the problem. The problem is we don’t know what to do even at the slightly higher level.
The reinforcement learning algorithm takes in the state of the fingers and piano keys, and outputs the required motor actions to perform well.
Also, as you are too lazy to read an article but still feel entitled to comment on it, I herby give you -1 reward. Let's see if that helps to improve your character.