Full inverse-dynamics realization with three Screw Attention layers

Develop a three-layer Screw Attention construction that exactly reproduces the full recursive Newton–Euler inverse-dynamics algorithm, including the successive computation of body velocities, accelerations, and wrenches.

Background

The paper establishes that Screw Attention can exactly represent the rigid-body velocity recursion with one layer and the Jacobian-transpose control law with an appropriate attention sweep and readout. It further argues that stacking three layers should reproduce the three dependent stages of the recursive Newton–Euler algorithm: computing body velocities, computing accelerations, and accumulating and projecting wrenches toward the base.

However, the experiments use only two layers, and the paper does not implement or validate the complete three-layer inverse-dynamics construction. The unresolved task is therefore to construct and verify a full inverse-dynamics realization within the Screw Attention architecture.