Passivity-Based Control of Human-Robotic Networks with Inter-Robot Communication Delays and Experimental Verification

In this paper, we present experimental studies on a cooperative control system for human-robotic networks with inter-robot communication delays. We first design a cooperative controller to be implemented on each robot so that their motion are synchronized to a reference motion desired by a human operator, and then point out that each robot motion ensures passivity. Inter-robot communication channels are then designed via so-called scattering transformation which is a technique to passify the delayed channel. The resulting robotic network is then connected with human operator based on passivity theory. In order to demonstrate the present control architecture, we build an experimental testbed consisting of multiple robots and a tablet. In particular, we analyze the effects of the communication delays on the human operator's behavior

非接触計測による自己キャラクタ対面合成型実映像対話システムE-VChatの評価

Abstract – We previously proposed an embodied video communication system called“E-VChat” in which a CG avatar is superimposed on the other talker’s video image in aface-to-face scene in order to comprehend the talkers’ mutual interaction during remotecommunication. Remote talkers can communicate interactively via their own avatar withthe partner’s video image, which moves based on the talker’s motion and automaticallygenerates motion based on the on-off pattern of the talker’s voice. This system uses aheadset-type motion capture device that reflects the talker’s head movements directlyusing acceleration and gyro sensors. Further, we demonstrated the effectiveness of theE-VChat system through a communication experiment.　In this paper, we propose an advanced E-VChat system that uses image processingto sense the talker’s head motion without wearing sensors for practical use, and discussthe development of a prototype of this system. We demonstrate the effectiveness of theself-avatar that uses the talker’s head motion and auto-generated motion based on speechinput through a communication experiment in which 12 pairs of subjects are evaluatedin three separate communication modes. In one mode, only head motion is used; in thesecond mode, motion is auto-generated based on speech input; and in the third mode,both the head motion and the auto-generated motion based on speech input is used. Inaddition, we confirm through a communication experiment the effectiveness of the superimposedavatar for a face-to-face floating projection based on the partner’s face anglein comparison with a bottom-center projection of the partner’s image irrespective of thepartner’s angle

Model following control with discrete time SMC for time-delayed bilateral control systems

This paper proposes a new algorithm based on model following control to recover the uncompensated slave disturbance on time delayed motion control systems having contact with environment. In the previous works, a modified Communication Disturbance Observer (CDOB) was shown to be successful in ensuring position tracking in free motion under varying time delay. However, experiments show that due to the imperfections in slave plant Disturbance Observer (DOB) when there is rapid change of external force on the slave side, as in the case of environment contact, position tracking is degraded. This paper first analyzes the effect of environment contact for motion control systems with disturbance observers. Following this analysis, a model following controller scheme is proposed to restore the ideal motion on the slave system. A virtual plant is introduced which accepts the current from the master side and determines what the position output would be if there was no environment. Based on the error bet ween actual system and model system, a discrete time sliding mode controller is designed which enforces the real slave system to track the virtual slave output. In other words, convergence of slave position to the master position is achieved even though there is contact with environment. Experimental verification of the proposed control scheme also shows the improvement in slave position tracking under contact forces

The control theory of motion-based communication: problems in teaching robots to dance

The paper describes results on two components of a research program focused on motion-based communication mediated by the dynamics of a control system. Specifically we are interested in how mobile agents engaged in a shared activity such as dance can use motion as a medium for transmitting certain types of messages. The first part of the paper adopts the terminology of motion description languages and deconstructs an elementary form of the well-known popular dance, Salsa, in terms of four motion primitives (dance steps). Several notions of dance complexity are introduced. We describe an experiment in which ten performances by an actual pair of dancers are evaluated by judges and then compared in terms of proposed complexity metrics. An energy metric is also defined. Values of this metric are obtained by summing the lengths of motion segments executed by wheeled robots replicating the movements of the human dancers in each of the ten dance performances. Of all the metrics that are considered in this experiment, energy is the most closely correlated with the human judges' assessments of performance quality. The second part of the paper poses a general class of dual objective motion control problems in which a primary objective (artistic execution of a dance step or efficient movement toward a specified terminal state) is combined with a communication objective. Solutions of varying degrees of explicitness can be given in several classes of problems of communicating through the dynamics of finite dimensional linear control systems. In this setting it is shown that the cost of adding a communication component to motions that steer a system between prescribed pairs of states is independent of those states. At the same time, the optimal encoding problem itself is shown to be a problem of packing geometric objects, and it remains open. Current research is aimed at solving such communication-through-action problems in the context of the motion control of mobile robots.Support for this work is gratefully acknowledged to ODDR&E MURI07 Program Grant Number FA9550-07-1-0528, the National Science Founda tion ITR Program Grant Number DMI-0330171, and the Office of Naval Research, and by ODDR&E MURI10 Program Grant Number N00014-10- 1-0952. (FA9550-07-1-0528 - ODDRE MURI07; DMI-0330171 - National Science Foundation ITR Program; Office of Naval Research; N00014-10-1-0952 - ODDRE MURI10

Monitoring of atopic dermatitis using leaky coaxial cable

In our daily life, inadvertent scratching may increase the severity of skin diseases (such as atopic dermatitis, etc.). However, people rarely pay attention to this matter, so the known measurement behavior of the movement is also very little. Nevertheless, the behavior and frequency of scratching represent the degree of itching, and the analysis of scratching frequency is helpful to the doctor's clinical dosage. In this paper, a novel system is proposed to monitor the scratching motion of a sleeping human body at night. The core device of the system are just a Leaky coaxial cable (LCX) and a router. Commonly, LCX is used in the blind field or semi blind field in wireless communication. The new idea is that the leaky cable is placed on the bed, then the state information of physical layer of wireless communication channels is acquired to identify the scratching motion and other small body movements in the human sleep process. The results show that it can be used to detect the movement and its duration. Channel state information (CSI) packet is collected by card installed in the computer based on the 802.11n protocol. The characterization of the scratch motion in the collected channel state information is unique, so it can be distinguished from the wireless channel amplitude variation trend

A soft actuation system for segmented reflector articulation and isolation

Segmented reflectors have been proposed for space based applications such as optical communication and large diameter telescopes. An actuation system for mirrors in a space based segmented mirror array was developed as part of NASA's Precision Segmented Reflector program. The actuation system, called the Articulated Panel Module (APM), provides 3 degrees of freedom mirror articulation, gives isolation from structural motion, and simplifies space assembly of the mirrors to the reflector backup truss. A breadboard of the APM was built and is described

E-VChat : 頭部動作連動型音声駆動身体引き込みキャラクタを対面合成した実映像対話システム

Abstract – We proposed an embodied video communication system in which a humantypeavatar called “VirtualActor” which represents interactive behavior is superimposedon the other speech partner’s video image in a virtual face-to-face scene. The effectivenessof a video communication system was demonstrated in an experiment of comparisonwith the scene in which a reduced own video image is superimposed on the other talker’svideo image using the picture-in-picture method. However, this system had some problems,such as the detailed adjustment of video images and the lack of portability of sensors.In this paper, we develop a headset-type motion-capture device which reflects the talker’shead movements directly using an acceleration sensor and gyro sensor, and employ a CGcharacter which moves based on talker’s own motion and generates motion automaticallybased on the on-off pattern of talker’s voice. Further, we propose the concept ofan embodied video communication system in which the CG character is superimposedon the other talker’s video image in a face-to-face scene, and develop a prototype called“E-VChat”. A communication experiment is performed to confirm the effectiveness ofthe E-VChat system for 12 pairs of subjects using three communication modes: “Headset,”“Headset + Generated motion automatically as a talker’s avatar,” and “Headset+ Generated motion automatically as an talker’s support agent.” The results show thatall communication modes tested are affirmatively assessed by sensory evaluation, andthe “Headset + Generated motion automatically as a talker’s avatar” mode is evaluatedhighly by a paired comparison. Finally, we develop a multiple-character E-VChat systemusing an audience that nods in response to the talker’s voice, and confirm the effectivenessof the system in an interview-style communication experiment