Smooth real-time motion planning based on a cascade dual-quaternion screw-geometry MPC
Ainoor Teimoorzadeh, Frederico Fernandes Afonso Silva, Luis F. C. Figueredo, Sami Haddadin
TL;DR
The paper addresses real-time, coordinate-invariant trajectory tracking for robotic manipulators under end-effector twist, acceleration, and jerk constraints. It couples screw-linear interpolation (ScLERP) in a dual-quaternion framework with a discrete-time MPC to enforce kinodynamic bounds along the path, producing a smooth, constraint-satisfying trajectory on $Spin(3)⋉R^3$. The key contributions are the integration of ScLERP with a QP-based MPC over horizons $n_c$ and $n_p$, a cascade architecture with outer twist-smoothing and inner-pose-tracking, and experimental validation on a $7$-DoF Franka Emika Panda showing constraint enforcement in real time. The approach enables safe, smooth real-time motion planning in cluttered or human-shybrid environments by preserving coordinate invariance and avoiding representation singularities.
Abstract
This paper investigates the tracking problem of a smooth coordinate-invariant trajectory using dual quaternion algebra. The proposed architecture consists of a cascade structure in which the outer-loop MPC performs real-time smoothing of the manipulator's end-effector twist while an inner-loop kinematic controller ensures tracking of the instantaneous desired end-effector pose. Experiments on a $7$-DoF Franka Emika Panda robotic manipulator validate the proposed method demonstrating its application to constraint the robot twists, accelerations and jerks within prescribed bounds.
