Isolation wards operate in quarantine rooms to prevent cross-contamination caused by infectious diseases. Behind the benefits, medical personnel can have the infection risk from patients and the heavy workload due to the isolation. This work proposes a robot-assisted system to alleviate these problems in isolation wards. We conducted a survey about the medical staff's difficulties and envisioning robots. Using the investigation result, we devised three valuable services using two kinds of heterogeneous robots: telemedicine, emergency alert, and delivery services by care robots and delivery robots. Our system also provides user-interactive components such as a dashboard for medical staff and a patient app for inpatients. To manage the services efficiently, we suggest the robotic system based on a central control server and a hierarchical management architecture. Through a user study, we reviewed the usability of the developed system and its future directions.

Verbal interaction between a human and a robot may play a key role in conveying suitable directions for a robot to achieve the goal of a user's request. However, a robot may need to correct task plans or make new decisions with human help, which would make the interaction inconvenient and also increase the interaction time. In this paper, we propose a new verbal interaction-based method that can generate plan models and execute proper actions without human involvement in the middle of performing a task by a robot. To understand the verbal behaviors of humans when giving instructions to a robot, we first conducted a brief user study and found that a human user does not explicitly express the required task. To handle such unclear instructions by a human, we propose two different algorithms that can generate a component of new plan models based on intents and entities parsed from natural language and can resolve the unclear entities existed in human instructions. An experimental scenario with a robot, Cozmo, was tried in the lab environment to test whether or not the proposed method could generate an appropriate plan model. As a result, we found that the robot could successfully accomplish the task following human instructions and also found that the number of interactions and components in the plan model could be reduced as opposed to the general reactive plan model. In the future, we are going to improve the automated process of generating plan models and apply various scenarios under different service environments and robots.

This study proposes an actuator whose design relies on a coordinated approach to control and hardware design: impedance control is supplemented with the introduction of a spring-damper coupler between the actuator and reference (ground). The coupler between the actuator and reference has the effect of further reducing the impedance apparent to the environment. Unlike traditional series elastic actuation, where the deformation of a physical spring coupler introduced between an actuator and link is fed back for control, our coupler is located between actuator and reference and its deformation is not fed back for control. The proposed control further employs time-delay estimation to account for the system dynamics that include both the physical and virtual couplers and to realize accurate and robust control over end-effector position and contact forces. We present a simple method for estimating interaction forces and regulating the contact force without a priori knowledge of the environment. A numerical simulation demonstrates the efficacy of the proposed approach.

An accurate and robust impedance control technique is developed based on internal model control structure and time-delay estimation: the former injects desired impedance and corrects dynamics estimation error; the latter estimates and compensates the nonlinear dynamics of robot manipulators. Owing to the simple structure, the proposed control is designed without requiring entire dynamics computation or complex algorithms. The accuracy and robustness of the proposed control are verified using a two degrees of freedom robot with stiff wall simulation. The proposed control realizes desired impedance accurately compared with other competent controllers throughout the task, i.e., free motion, constrained motion, and transition between these motions. Further, proposed control realizes four sets of desired impedance accurately. Thus, accuracy and robustness of proposed control is confirmed.

This paper presents stability analysis and experimental results of the nonlinear bang-bang impact controller for robotic manipulators. A stability condition has been derived based on the analysis in Ln ∞ space and its physical interpretation has been given. The analysis shows that the stability of nonlinear bang-bang impact control depends on sampling time and the accuracy of inertia estimation. Stability is enhanced with the decrease of changes in the Coriolis, centrifugal, and disturbance forces. The stability condition is verified by simulations and experiments. Experiments show that overall performance is comparable to or better than existing impact control techniques which employ more complicated control strategies.