Robot Dynamics Learning and Human-Robot Interaction
           

- 指導教授 黃漢邦 博士 研究生 鄭敬安

- Advisor :Dr.Han-Pang Huang Student : Ching-An Cheng


Lab. of Robotics., Department of Mechanical Engineering, National Taiwan University, Taiwan

Abstract:

The need of robots in industries or as the service robots grows significantly in recent decades. Recently, many researches are devoted in the human-robot interactions. For examples, the collaborative working, the service robots for touring or attentive home care, or the exoskeletons for augmenting human powers or assisting the patient for normal functionalities are of interests. In the human-robot interaction, the modeling and the control of the dynamics are essential. With better modeling of the dynamical system, the robot can sensor more and provide accurate and precise responses, whereas the control scheme ensures the safety robustly and let the robot react in a human-friendly way. For better development and the control of the robot in the next generation, this thesis is devoted to the robot dynamics learning and the control of the human-robot interaction with applications in the three topics: the learning of the robot dynamics with the structured kernels, the virtual impedance control for safe human-robot interaction, and the Bayesian exoskeleton.

To model the robot dynamics automatically and accurately, the structured kernel concerns the system identification with the machine learning techniques. It is well-known that the proper model of the robot can boost the performance of the control. The tradition parametric models based on the analytic formulation are often too complex for general systems, while the other methods such as the autoregressive-moving-average (ARMA) model or the general machine learning models introduce either bias or variance in learning. The interest here is how to design a general system identification scheme that enjoys the benefits of both. The proposed kernels are designed so that not only the structures of the analytic model is implicitly modeled but the system can be identified as the blackbox as in the machine learning approaches. In short, the proposed method is a system identification framework that learns the system automatically without any derivation of the system dynamics and yet converges to analytic model pointwisely as the number observations goes to infinity. For the control of the human-robot interaction, the virtual impedance control and the Bayesian exoskeleton system are proposed. For the robots with individual functionalities, the virtual impedance control is designed for the robust, smooth, and consistent collision avoidance that the robot can avoid all the possible collisions robustly while trying to accomplish the original task. Therefore, the robots can response the human nearby safely and compliantly. As for the robots on the human body, the Bayesian exoskeleton system assists human operators with the robust hybrid control. In the Bayesian exoskeleton system, the Bayesian estimator inferences the human intention adaptively, and the inner assistive torque control can ensure the robustness of the system by considering the ability of the operator. Therefore, the resultant exoskeleton system can ensure both the safety and the effective assistance.





中文摘要:


近幾年來,工業機器人以及服務機器人的需求正大幅增加,尤其人機互動的設計尤其受到重視,如機器人和人的偕同工作、用於導覽與居家看護的服務型機器人,或是能夠增強人類力量或是輔助病人復健的外骨骼機器人。而在人機互動的設計中,最重要的在於建模和控制,因為好的動態模型代表機器人能夠感測更多資訊並且能夠執行更精準的動作,而控制則關於安全、穩健的人機互動。為了下個世代機器人的發展和控制,本論文致力機器人動態學習以及人機互動的控制,並應用於以下三個主題:使用結構化再生核希爾伯特學習空間機器人動態、虛擬阻抗控制以及其在安全人機互動的應用、貝氏外骨骼系統。

為了能夠更準確以及更快速識別系統,結構核空間是一使用機器學習的技巧進行系統識別的架構。雖然適當的模型可以增加控制的效果,但傳統上,推導參數模型往往過於複雜,而廣義的機器學習方法則會引進偏差或是變異。因此,我們希望能夠設計一個方法綜合兩種方法的優點。所提出的核函數隱含了解析解並且能夠以黑盒子的方式學習,因此可以在不需推導系統的動態之下自動地識別系統,且所建構出的模型可以收斂至解析解。另外為了在非結構化空間中安全的人機互動,我們使用虛擬阻抗控制機器人,使得機器人在不論面對何種障礙物都以達到穩健、圓滑及一致的方式迴避障礙物,因此機器人可以在避免各種的碰撞下安全地進行它原本的任務。最後主題則是關於貝氏外骨骼系統的設計,運用適應性的輔助控制讓機器人可以最佳的回應操作者的意念。因此,外骨骼系統能夠同時兼顧安全以及有效的輔助控制。