四足ロボットの足姿勢を触覚遠隔操作で環境探索・操作する制御フレームワーク
Bounded haptic teleoperation of a quadruped robot's foot posture for sensing and manipulation
四足ロボットの1脚と胴体を協調制御し、7自由度触覚ジョイスティックで足先の力覚探索と操作を遠隔実行できるようにした。摩擦円錐とトルク制限を考慮した操作範囲の制限で転倒や滑りを防ぐ。
著者: Guiyang Xin, Joshua Smith, David Rytz, Wouter Wolfslag, Hsiu-Chin Lin, Michael Mistry
分類: cs.RO, cs.SY, eess.SY
原文アブストラクト
This paper presents a control framework to teleoperate a quadruped robot's foot for operator-guided haptic exploration of the environment. Since one leg of a quadruped robot typically only has 3 actuated degrees of freedom (DoFs), the torso is employed to assist foot posture control via a hierarchical whole-body controller. The foot and torso postures are controlled by two analytical Cartesian impedance controllers cascaded by a null space projector. The contact forces acting on supporting feet are optimized by quadratic programming (QP). The foot's Cartesian impedance controller may also estimate contact forces from trajectory tracking errors, and relay the force-feedback to the operator. A 7D haptic joystick, Sigma.7, transmits motion commands to the quadruped robot ANYmal, and renders the force feedback. Furthermore, the joystick's motion is bounded by mapping the foot's feasible force polytope constrained by the friction cones and torque limits in order to prevent the operator from driving the robot to slipping or falling over. Experimental results demonstrate the efficiency of the proposed framework.
