\page md_doc_a-features_g-dynamic Dynamics algorithms

Inverse dynamics

The Recursive Newton-Euler Algorithm (RNEA) computes the inverse dynamics: given a desired robot configuration, velocity and acceleration, the torques required to execute this motion are computed and stored. The algorithm first performs a forward pass (equivalent to second-order kinematics). It then performs a backward pass, computing the wrenches transmitted along the structure and extracting the joint torques needed to obtain the computed link motions. With the appropriate inputs, this algorithm can also be employed to compute specific terms of the dynamic model, such as the gravity effects.

Joint-space inertia matrix

The Composite Rigid Body Algorithm (CRBA) is employed to compute the joint space inertia matrix of the robot. We have implemented some slight modifications of the original algorithm that improve the computational efficiency.

Forward dynamics

The Articulated Body Algorithm (ABA) computes the unconstrained forward dynamics: given a robot configuration, velocity, torque and external forces, the resulting joint accelerations are computed.

Additional algorithms

Beside the algorithms above, other methods are provided, most notably for constrained forward dynamics, impulse dynamics, inverse of the joint space inertia and centroidal dynamics.