Constrained EKF

[aceglia]

Could be very usefull to have a EKF for inverse kinematics which is constrained into the joint angle range of motion like in : https://ieeexplore.ieee.org/document/7523749.
Not urgent but great enhancement I think.

[aceglia]

Add sigmoid function to add bound to states : Constrained Dynamic Parameter Estimation using the Extended
Kalman Filter. I think more easy than the previous article.