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.

Most range-only simultaneous localization and mapping (RO-SLAM) algorithms have considered direct measurements between robot and its neighbor nodes only, even though other inter-node measurements can be actively used to improve the performance. In addition, most of them assume nodes are static, i.e., fixed on one place and cannot be applied to dynamic environments where some or all of nodes are moving. To address the aforementioned issues, a cooperative dynamic RO-SLAM (CDRO-SLAM) is proposed in this paper, which is a RO-SLAM algorithm based on sum of Gaussian (SoG) filter with cooperative measurements in dynamic environments. The proposed CDRO-SLAM integrates all the inter-node measurements for localization, which results in a smaller map estimation error with a faster convergence speed than the conventional ROSLAM. Moreover, the proposed CDRO-SLAM can also track movement of any nodes under the dynamic environment by resetting and updating the SoG variables. Such advantages of the proposed CDRO-SLAM algorithm are verified with the real experimental data.

This paper provides a robust fusion algorithm for accurate position estimation under uncertain large errors in range measurements. Many researchers have studied UWB, IMU, odometry integration algorithms for estimating position, velocity, attitude and IMU biases. However, the fused results of these conventional algorithms are likely to be affected by the unusual ranging measurement errors. Therefore, in order to improve the positioning accuracy under the large errors of the UWB range, a robust fusion algorithm is required. In this paper, instead of using the range directly, the estimated range that the errors is reduced is used. Reducing the errors is possible by using the odometry velocity that is relatively accurate and is independent of range measurement. The robustness and accuracy of the proposed algorithm is verified by a mobile robot with real-time positioning and trajectory control under large range errors which are occurred randomly.

In the received signal strength (RSS) based localization, a model-based calibration approach has been usually done by relating RSS-to-distance among anchor nodes. In this paper, an improved calibration method is proposed. For that purpose, RSS and estimated distance between any pairs of an-chor/unknown nodes is considered under the linear regression model. Unfortunately in this model, partial input elements are erroneous due to the inaccurate localization of unknown nodes. To obtain its solution under consideration of such an error, the weighted total least squares (WTLS) techniques are employed here. With the help of the WTLS techniques, several errors involved in the model can be effectively compensated. To show the efficiency of the proposed calibration, it is combined with several localization algorithms and its performance is verified by various simulations. The results show that the proposed calibration can give a very similar localization performance to that of each localization algorithm when true model parameters are known.

In order to control a robot, motion data obtained from various interface devices such as haptic and tele-operating interfaces, and a motion capture system, or from predefined parametric equations are needed. It is hard to store and transmit the data because of their high control frequency and synchronization problem. In addition, usually, all these data are only for one target robot system, i.e., it is hard to use them to other robot system with different hardware limits. In order to solve the problems, the reduction of the original data is conducted with two stage magnitude quantization and the restoration without violating the hardware limits, such as maximum velocity, acceleration, etc., is conducted with the convolution interpolation, in this paper. The proposed method can be used in on-line data transmission and for off-line data storage.

This paper proposes a strategy for grasp and manipulation of unknown objects. In order to derive force relations of fingers, the groped shape of soft fingers is introduced. The groped shape is not equal to the real object shape, but is tightly related to the force equilibrium of fingers. By considering contact forces of the groped shape, a simple control parameters can be derived. The manipulation of an object is easily accomplished by embedding the concept of virtual centroid into the grasp control to redistribute internal forces. With these concepts, an object can be easily translated, rotated, and manipulated by relocating fingers. The proposed method is verified with experiments.

This paper presents a development of an anthropomorphic robot hand, `KITECH Hand' that has 4 full-actuated fingers. Most robot hands have small size simultaneously many joints as compared with robot manipulators. Components of actuator, gear, and sensors used for building robots are not small and are expensive, and those make it difficult to build a small sized robot hand. Differently from conventional development of robot hands, KITECH hand adopts a RC servo module that is cheap, easily obtainable, and easy to handle. The RC servo module that have been already used for several small sized humanoid can be new solution of building small sized robot hand with many joints. The feasibility of KITECH hand in object manipulation is shown through various experimental results. It is verified that the modified RC servo module is one of effective solutions in the development of a robot hand.

In recent, control approaches for the human-like behavior in the field of service robotics have been attracting considerable attention, since most humans or animals perform various tasks uncomplicatedly. Hence simple control methods based on gaining a physical insight into human reaching movement in redundancy of DOFs have been proposed. In comparison with the conventional approaches, the proposed method tries to control directly robotic systems in task-space with the control signal composed of linear superposition of three terms 1) joint-damping, 2) virtual spring, and 3) virtual damper in task-space. In particular, our work contains a muscle tension effect of a human under the gravity. This give birth to energy efficient natural motions avoiding problems on repeatability of the motion and ill-posedness problems emerged in most of redundant DOF systems. Thus, this paper exhibits expendability of the position control into the orientation control and compliant behavior. It is verified with a real robotic arm that satisfies human-like movements and motion repeatability under kinematic redundancy of joints.

There are many difficulties in operating a humanoid which has high degree-of-freedom and instability in balancing its body. In addition, due to the shape of a humanoid, it is expected to have motions like a human. In order to overcome its operational difficulties and to provide a humanlike motion, a teleoperation with the motion imitation is studied in this paper. Specifically, a framework for online generation of a footprint from a human walking motion is proposed. The human walking motions acquired from a motion capture device are parameterized and normalized to give a human independent foot motion. The normalized parameters are restored by a humanoid considering its hardware limit. The restored footprints generate a walking trajectory of a humanoid, which imitates the human walking motion in terms of the footprint. Experiments are conducted with MAHRU-R, a humanoid robot developed in KIST.

This paper presents a characterization of the Hokuyo UBG-04LX-F01 laser rangefinder (LRF). The Hokuyo LRFs are suitable for a small mobile robot due to their small size and light weight. In particular, the scan frequency of Hokuyo UBG-04LX-F01 is higher than those of the previous LRFs in its price range. However, there is no research on characterizing this LRF for the convenience of practical use. Therefore, this paper characterizes the Hokuyo UBG-04LX-F01 and analyzes the effect of the target properties, such as incidence angle, color, brightness, and material, by measuring the distance to a target. The experimental results show that the measurement error is strongly influenced by the incidence angle and the brightness of the target surface. From the experimental results, a calibration model is also proposed to measure the accurate distance to a target.

This paper proposes a new walking pattern generation method for humanoid robots. The proposed method consists of feedforward control and feedback control for walking pattern generation. The pole placement method as a feedback controller changes the poles of system in order to generate more stable and smoother walking pattern. The advanced pole-zero cancellation by series approximation (PZCSA) as a feedforward controller plays a role of reducing the inherent property of linear inverted pendulum model (LIPM), that is, non-minimum phase property due to an unstable zero of LIPM and tracking efficiently the desired zero moment point (ZMP). The efficiency of the proposed method is verified by three simulations such as arbitrary walking step length, arbitrary walking phase time and sudden change of walking path.

This paper proposes a new walking pattern generation method for humanoid robots. This paper uses the linear inverted pendulum model (LIPM) which is composed of zero moment point (ZMP) and center of mass (CoM). Based on LIPM, the proposed method consists of feedforward control and feedback control for walking pattern generation of humanoid robots. The linear quadratic regulator(LQR) as a feedback controller tracks the desired ZMP according to footprints of humanoid robots and makes poles of LIPM stable. The feedback controller, pole-zero cancelation by series approximation (PZCSA) plays a role of reducing the inherent property of LIPM and approximating the transfer function of the overall system including LIPM and controllers to be unity. The usefulness of the proposed method is verified by simulations such as arbitrary time intervals of support phases, arbitrary desired ZMP position and sudden changed desired ZMP position. And the validity of the proposed method is confirmed by the experiment of a humanoid robot using a joystick.

This paper presents balance and vibration control algorithm for bipedal humanoid robots in the motion embedded CoM Jacobian framework. The vibration control is employed during a single supporting phase, which can suppress residual vibration of the un-modelled flexibility. Because the previously proposed walking control method in the resolved momentum control framework is based on the rigid body motion, vibration control algorithm which compensates for residual vibration can make the humanoid motion into rigid body motion. The vibration control consists of the modified global planning CoM trajectory and modified ankle joint controller in the motion embedded CoM Jacobian framework. The parameters of the controller are acquired easily using MATLAB System Identification Tool box. Also, balance control algorithm which controls body orientation is applied to the whole body coordination framework. By dynamic walking experiments using a humanoid robot MAHRU-R, the validity of the proposed control methods is verified.

Research on human-robot interaction has recently been getting increasing attention. In the research field of human-robot interaction, speech signal processing in particular is the source of much interest. In this paper, we report on a speaker localization system with six microphones for a humanoid robot called MAHRU of KIST and propose a time delay of arrival (TDOA)-based feature matrix with its algorithm based on the minimum sum of absolute errors (MSAE) for sound source localization. The TDOA-based feature matrix is defined as a simple database matrix calculated from pairs of microphones installed on a humanoid robot. To verify the solid performance of our speaker localization system for a humanoid robot, we present the various experimental results for the speech sources at all directions within 5 m distance and the height divided into three parts.

A network-based robot is a robot that explores service servers in the network environment for analyzing sensor data and making decision. Since network-based humanoid architecture was proposed, it's possible to reduce costs of robots. We hope robots will be all around at each home. Therefore, normal users who are not experts need to be able to control various robots with easy commands. We developed a scripting language, named CCSLR (Common Command-Scripting Language for network-based Robots) to help users and developers who control various robots in ubiquitous environments. If a user composes a script in CCSLR commands, CCSLR translator system translates the script into suitable low-level command. Therefore, with a set of high-level commands, CCSLR is able to represent low-level commands in common way. Before making the robotic system understand commands that a user input, first, we need to determine what command is. High-level command should lit into both a user intention and a low-level control for heterogeneous robots. We developed the CCSLR and its translator system within the network-based humanoid architecture [1].

This paper proposes the walking pattern generation method, the kinematic resolution method of center of mass (CoM) Jacobian with embedded motions, and the design method of posture/walking controller for humanoid robots. First, the walking pattern is generated using the simplified model for bipedal robot. Second, the kinematic resolution of CoM Jacobian with embedded motions makes a humanoid robot balanced automatically during movement of all other limbs. Actually, it offers an ability of whole body coordination to humanoid robot. Third, the posture/walking controller is completed by adding the CoM controller minus the zero moment point controller to the suggested kinematic resolution method. We prove that the proposed posture/walking controller brings the disturbance input-to-state stability for the simplified bipedal walking robot model. Finally, the effectiveness of the suggested posture/walking control method is shown through experiments with regard to the arm dancing and walking of humanoid robot.

This paper proposes the walking pattern generation method, the kinematic resolution method of CoM (center of mass) Jacobian with an embedded motion, and the walking controller design method for humanoid robots. First, the walking pattern is generated using the simplified model for bipedal robot. Second, the kinematic resolution of CoM Jacobian with embedded motion makes a humanoid robot balanced automatically during the movement of the all other limbs. Actually, it offers the ability of whole body coordination to the humanoid robot. Third, the walking controller is composed of the CoM controller minus the ZMP (zero momentum position) controller. Also, we show that the proposed walking controller brings the disturbance input-to-state stability (ISS) for the simplified bipedal walking robot model. Finally, the effectiveness of the proposed kinematic resolution method and walking controller is shown through experiments in regard to humanoid robot dancing and walking

Humanoids have a large set of basis behaviors and could perform various tasks. Controlling a humanoid with many degrees of freedom and behaviors consumes a lot of resources. By exploring the external service servers on the network, the ability of a humanoid is extendable beyond its resource constrains. This system is named network-based humanoid. In this paper, the network-based humanoid architecture (NBHA) is proposed to provide a core framework to develop this network-based humanoid system. It creates a system where humans, robots, and external service servers can interact without complicated configuration. Using this architecture, behaviors can be created, added and removed dynamically. A number of experiments have been conducted successfully by using JadeLeap middleware, FIPA standard and JESS rule engine on our humanoid. Experimental results show that the proposed architecture provides the extendable behavior control system in the network environment, decreases the development time for adding new services and it decreases the time for network connection of robots and user devices

In this paper, a network-based humanoid architecture (NBHA) is proposed. NBHA is a distributed architecture that based on multi-agent technology to provide a systematic method for developing humanoid software system, external services and coordinating them in an effective manner. Behaviors of these humanoids and their surrounding network environment can be created, added and removed dynamically via a simple scripting method. Some experiments on our network-based humanoid are presented in this paper. Experimental results show that the multi-agent architecture is a good selection for developing this system. It provides an extendable behavior control method in the network environment and it decreases the development time for adding new services. Using this distributed multi-agent architecture, roles of a humanoid, method for coordination and performing scenario can be changed easily

A general formulation to obtain an analytic Jacobian matrix for in-parallel manipulators has not been developed yet, although several authors addressed it. This paper suggests a consistent approach to obtain the instantaneous kinematic relation of in-parallel manipulators, by extending the results of screw theory to the forward and inverse instantaneous relations, and gives a formula that can obtain a reciprocal screw analytically without considering geometric relations.

An analytic expression for the singularities of a six-degree of freedom Stewart-platform type parallel manipulator (six-DOF SPM) is obtained using the concept of a local structurization method (LSM) with extra sensors. The resulting equation, however, does not include sensor values. It is only a function of design variables. The equation is basically a third-degree polynomial and it exactly provides singularity information of general SPMs. Several symbolic examples are shown to verify the exactness of the singularity equation by comparing it with previously reported singularities. Some other numerical examples are also shown using the proposed singularity equation.

The analytic expression for the singularities of 6-DOF SPM (Stewart-platform type parallel manipulator) is obtained using the concept of LSM (local structurization method) with extra sensors. The resulting equation, however, does not include sensor values, but is a function of design variables. The equation is basically a third-degree polynomial and it exactly provides singularity information for general SPMs. Several symbolic examples are shown to verify the exactness of the singularity equation by comparing it with the previously reported singularities.

Since parallel manipulators have relatively small workspace when compared to serial manipulators, it is important to determine the workspace in the design stage. However, due to the complexity of the closed-loop chain mechanism, the determination of the workspace is difficult. In this paper, a fully geometrical method for the determination of the workspace of 6-DOF parallel manipulators is presented using the concept of a 4-bar linkage. The reachable and dexterous workspace can be determined from the proposed algorithm. In order to evaluate the workspace, each leg is considered as an open chain, and two kinematic constraints-position and mechanism constraints-are developed. The proposed method is verified by simulation.

Generally, singularity analysis of 6-DOF parallel manipulators is very difficult and, as a result, the velocity relation has many uncertainties. Many researchers have reported that the forward position kinematics can be solved more easily with extra sensors. However, the relation of the velocity kinematics with extra sensors has not been fully studied yet. In this paper, an alternative method using the local structuralization method (LSM) for the analysis of singular configurations is presented. With LSM, the velocity relation can be represented in a simple form, and the result is totally equivalent to the conventional velocity relation. The velocity relation suggested in this paper gives a closed-form solution of singularities.