仮想フィクスチャで強化された可変アドミタンス制御における安定性・感度・透明性の解析
On the Analysis of Stability, Sensitivity and Transparency in Variable Admittance Control for pHRI Enhanced by Virtual Fixtures
物理的人間-ロボットインタラクション(pHRI)向けのプロキシベース制約付きアドミタンス制御について、伝達弾性やモータ速度飽和、駆動遅延などの寄生効果を考慮して不安定性の原因を分析し、制御パラメータが安定性に与える影響を実験的に評価した。さらに透明性を最大化するプロキシパラメータ適応手法を提案し、シミュレーションと実験で検証した。
著者: Davide Tebaldi, Dario Onfiani, Luigi Biagiotti
分類: cs.RO, cs.SY, eess.SY
原文アブストラクト
The interest in Physical Human-Robot Interaction (pHRI) has significantly increased over the last two decades thanks to the availability of collaborative robots that guarantee user safety during force exchanges. For this reason, stability concerns have been addressed extensively in the literature while proposing new control schemes for pHRI applications. Because of the nonlinear nature of robots, stability analyses generally leverage passivity concepts. On the other hand, the proposed algorithms generally consider ideal models of robot manipulators. For this reason, the primary objective of this paper is to conduct a detailed analysis of the sources of instability for a class of pHRI control schemes, namely proxy-based constrained admittance controllers, by considering parasitic effects such as transmission elasticity, motor velocity saturation, and actuation delay. Next, a sensitivity analysis supported by experimental results is carried out, in order to identify how the control parameters affect the stability of the overall system. Finally, an adaptation technique for the proxy parameters is proposed with the goal of maximizing transparency in pHRI. The proposed adaptation method is validated through both simulations and experimental tests.
