This paper discusses biomimetic water strider robots that have microfabricated hydrophobic legs. Various kinds of supporting legs with hydrophobic microstructures on their surfaces were developed using MEMS (micro electromechanical systems) techniques. The lift and pull-off forces of these supporting legs were analyzed theoretically and then measured. The experimental results were in good agreement with the calculations. Two different mechanisms for autonomous water strider robots were developed. One robot with twelve microfabricated legs driven by a vibration motor successfully moved on a water surface and also made left/right turns by exploiting differences in the resonant frequencies of the legs. The other robot, with six microstructured legs, moved on water through elliptical motion of its middle legs, which is similar to the motion of actual water striders.

Minimally invasive surgery (MIS) has become very common in recent years, thanks to the many advantages it provides for patients. Since it is difficult for surgeons to learn and master this technique, several training methods and metrics have been proposed, both to improve the surgeon's abilities and also to assess his/her skills. This paper presents the use of the WB-1R (Waseda bioinstrumentation system no.1 refined), which was developed at Waseda University, Tokyo, to investigate and analyze a surgeon's movements and performance. Specifically, the system can measure the movements of the head, the arms, and the hands, as well as several physiological parameters. In this paper we present our experiment to evaluate a surgeon's ability to handle surgical instruments and his/her depth perception using a laparoscopic view. Our preliminary analysis of a subset of the acquired data (i.e. comfort of the subjects; the amount of time it took o complete each exercise; and respiration) clearly shows that the expert surgeon and the group of medical students perform very differently. Therefore, WB-1R (or, better, a newer version tailored specifically for use in the operating room) could provide important additional information to help assess the experience and performance of surgeons, thus leading to the development of a global performance index for surgeons during MIS. These analyses and modeling, moreover, are an important step towards the automatization and the robotic assistance of the surgical gesture.

Personal robots, which are expected to become popular in the future, are required to be active in joint work and community life with humans. Such robots must have no bad physical or psychical effect on humans. The psychical effect of a robot on humans has been subjectively measured using questionnaires. However, it has not been objectively measured yet. Human emotion and the consciousness direction can be measured by physiological parameters and body motion, respectively. Therefore, the bioinstrumentation system WB-1 was developed in order to objectively measure the psychical effect of a robot on a human. It can measure physiological parameters such as respiration, heart rate, perspiration and pulse wave, and arm motion. Analyzing human stress in the interaction with a robot from electrocardiogram, the robot could generate a motion for decreasing the stress

Presently, the simple head model (hereinafter referred to as phantom for practical training) with dentition models is used for dental therapy training. We suggested the patient robot for dental therapy training (hereinafter referred to as patient robot) as one of the practical applications of the humanoid robot technology, and we actually developed patient robots. One of them is the general model provided with 14 degrees of freedom (DOF) in addition to a tongue and lips that may interfere with treatment, allowing reflection of any change in simple expression. Also, active motions of the neck or hand allow various impediments so as to interfere with the actual potential treatment. The robot allowed trainees to do dental therapy training closer to the actual practice involving avoidance of these risks

This paper describes development of a new human-like talking robot WT-4 (Waseda Talker No. 4). WT-4 was developed to overcome the problems related to the lack of variation in the formant frequency of the sounds generated by the previous talking robot WT-3. These problems arose particularly on the first formant (F1) where frequencies of less than 500 [Hz] could not be reached. And the differences among WT-3’s vowels were not clear; which may have been caused by the sound source of the vocal cords and the lips. Therefore, the connection between the vocal cords and the vocal tract was improved, as well as the lips mechanism. As the result of these improvements, WT-4’s sounds were quite similar to a human’s, and WT-4 was able to reproduce suitable sounds using auditory feedback.

This paper describes the development and experimental results obtained using a silkworm handling robot. This study was performed to establish a system for the handling of silkworms, and to make use of automated breeding to produce usable materials. Silkworms are soft and amorphous. Therefore, gripping them is extremely difficult, and requires a specialized handling system. The authors devised a gripping strategy, taking into consideration damage of the very supple silkworms, which was used successfully for the handling of silkworms.

Personal robots, which are expected to become popular in the future, are required to be active in joint work and community life with humans. Therefore, we have been developing new mechanisms and functions for a humanoid robot that has the ability to express emotions and to communicate with humans in a human-like manner. In 2004, we introduced the "Behavior Model" and "Consciousness Model" to the robot mental model so that the robot generated various kinds of behavior and an object of the robot's behavior became clear. We implemented the mental model in the emotion expression humanoid robot WE-4RII (Waseda Eye No.4 Refined II). Also, we have been studying a system of multiple harmonic oscillators (neurons) interacting via chaotic force since 2002. Each harmonic oscillator is driven by chaotic force whose bifurcation parameter is modulated by the position of the harmonic oscillator. In this paper, we propose an associative memory model using mutually coupled chaotic neural networks for generating an optimum behavior to a stimulus. We implemented this model in the emotional expression humanoid robot WE-4RII (Waseda Eye No.4 Refined II).

We have developed a new talking robot, WT-5 (Waseda Talker No. 5), having novel vocal cords and lips based on human biological structures. The vocal cords are made from the thermoplastic rubber "Septon", available from Kuraray Co. Ltd, which has a similar elasticity to human tissue. The vocal cord model was constructed with a similar structure to the biological structure of the human vocal cords. The vocal cords vibrated like those of a human. The new lips were able to attain a large deformation in a similar manner to human lips, without the leakage of air. This allowed clear pronunciation of vowels. With these new mechanisms, the robot could reproduce human speech in a more biological manner and could produce voices closer to those of a human.

This paper describes the development of a multi-degrees of freedom (DOF) flexible robot based on the tongue. The authors focused on the tongue because of its "flexibility" and "soft motion." The robot performs motions characteristic of the tongue: i.e., up-down and right-left motion of tip, and up-down, right-left, twisting, and circular motion of the whole. The robot's forms were defined as a 1D form (a shape like a string), a 2D form (a shape like a sheet of paper), and a 3D form (a solid structure). In Stage 1, the robot consists of three parts: the tip, the body, and the base. This robot enabled realization of basic motion and 1-2D form. To transform 3D form, the whole robot will be built up from the basic units. Basic unit is tip part mechanisms in Stage 1. The basic formula for controlling the basic unit is indispensable in designing a robot from basic units. Thus, the basic formula was sought. Moreover, the basic unit was evaluated using the basic formula.

We have developed a multi-DOF flexible robot modeled on deoxyribonucleic acid (DNA), the basis of heredity. DNA consists of bases, phosphate, and sugars that form a double helix, which can form a superhelix. In the present study, this double helix was modeled as a serial mechanism of 3-DOF basic units. The results of simulations with this model showed that it can form a superhelix. In addition, we built a robot consisting of 10 units with shape memory alloy to demonstrate that a superhelix can be developed.

Since 1990, we have been developing anthropomorphic flutist robots, which are mechanically similar to human organs needed for playing the flute. The goal of this research is to clarify the flute playing mechanism from an engineering point of view and to enable the communication with humans at emotional level. The control of the air beam parameters for obtaining a good sound is very important. Such parameters are related mainly to the lips shape and its relative position respect to the flute embouchure hole. Then, the newest version of the anthropomorphic flutist robot WF-4 has been implemented by improving the design of each part of the robot (lips, lungs, neck, etc.). This new version has succeeded in the improvement of the flute sound quality and the sound conversion efficiency. We describe the mechanical features of the WF-4 and the experiments done for evaluating its musical performance.

The authors have been developing humanoid robots in order to develop new mechanisms and functions for a humanoid robot that has the ability to communicate naturally with a human by expressing human-like emotion. We considered that human arms play an important role. And, in 2003, we developed the 9-DOFs emotion expression humanoid arm. Then, we developed the emotion expression humanoid robot WE-4R (Waseda Eye No.4 Refined) by integrating the new arms into the human-like head robot WE-4. Moreover, we introduced the new control algorithm for robot arm with redundant DOF into WE-4R. The new control algorithm was described by the junction of geometric constraint and robot emotion. We describe the mechanical design and the control algorithm of 9-DOFs emotion expression humanoid arm.

This paper describes the mechanisms and the speech production of a new advanced talking robot WT-3 (Waseda Talker-No.3) that improves on WT-2 (Waseda Talker-No.2) and is based on human acoustic theory for the reproduction of human speech. WT-3 consists of 1-DOF lungs and 3-DOF vocal cords and articulators (the 7-DOF tongue, 5-DOF lips, 1-DOF teeth, nasal cavity and 1-DOF soft palate), and can reproduce human-like articulatory motion; the total DOF is 18. The oral cavity is designed based on the MRI images of the human sagittal plane, although the cross section of the vocal tract is rectangular in shape except for the mouth. The width of the vocal tract is 30 [mm]. The average length of the vocal tract is approximately 175 [mm] and the same as that of a human's. Compared to the previous robots, WT-3 can produce vowels more clearly, and produce stops, fricatives and nasal sounds with the new flexible mechanisms that function as the human vocal tract area and the other mechanisms. WT-3 can mechanically reproduce human speech.

We developed a jaw movement training robot system implementing a 6-degree of freedom (DOF) parallel mechanism, and applied it to jaw opening and closing training, which is one of the therapies for temporomandibular joint disorders. As one application of this system, we developed an intermaxillary traction therapy system that provides non-physiological movements, whereby the patients' jaws receive traction to regenerate healthy temporomandibular joint tissue. This therapy is especially effective for patients with a symptom called "open bite", i.e. those who cannot completely close their jaws. Additionally, the previously developed mastication robot was applied to this robot system as a patient model, and the training movements of the training robot were evaluated.

This paper describes the development of a multi-DOF (degrees of freedom) flexible robot based on the tongue. The authors focused on the tongue because of its "flexibility" and "soft motion". Motion of this robot is realized mechanically, and flexibility is achieved by covering the mechanism with a flexible structure. This robot consists of three parts: the tip, the body, and the base. In future, it would be applied in medical fields, e.g., for assistance in dysphemia, or in industrial fields, etc.

The authors have been developing humanoid robots in order to develop new mechanisms and functions for a humanoid robot that has the ability to communicate naturally with a human by expressing human-like emotion. We considered that human hands play an important role in communication because human hands have grasping, sensing and emotional expression abilities. Then, we developed the emotion expression humanoid robot WE-4RII (Waseda Eye No.4 Refined II) by integrating the new humanoid robot hands RCH-1 (RoboCasa Hand No.1) into the emotion expression humanoid robot WE-4R. Furthermore, we confirmed that RCH-1 and WE-4RII had effective emotional expression ability because the correct recognition rate of WE-4RII's emotional expressions was higher than the WE-4R's one. In this paper, we describe the mechanical features of WE-4RII.

This paper describes an autonomous control method of an anthropomorphic talking robot WT-4 (Waseda Talker No.4) to mimic continuous human speech sounds by auditory feedback. WT-4 consisted of 1-DOF lungs, 4-DOF vocal cords and articulators (the 7-DOF tongue, 5-DOF lips, 1-DOF teeth, nasal cavity and 1-DOF soft palate), and could reproduce human-like articulatory motion; the total DOF was 19. In this method, the trajectory of each robot parameter was controlled so that the acoustic parameters (pitch, sound power, formant frequencies that are resonant frequencies of the vocal tract and have the peak of the output spectrum, and the timing of the switch between voiced and voiceless sounds) generated from the robot were close to those of human speech sounds. The trajectory of each robot parameter was optimized by inputting the acoustic parameters. This method would help to clarify the human speech mechanism and to create a new speech production system.

This paper describes the development and experimental results of a silkworm handling robot. Silkworm handling robot was developed for the purpose of automated breeding of silkworm larvae. The silkworm larvae are soft and amorphous. Therefore, gripping them is extremely difficult, and requires a specialized handling system. The authors succeeded in handling of a silkworm larva.

In this paper, we describe an anthropomorphic flutist robot that it's expected to have human-like organs from the mechanical hardware and control functions. We developed a "General Position" searching algorithm, which is based on the relative distance between the robot's mouth and the flute mouthpiece. It is possible for the robot, using the General Position, to blow a whole tone. Thereafter, we developed an autonomous searching algorithm for the lip part parameters after setting the General Position, and an algorithm for evaluating the blowing sound. The robot could stably play a flute using these algorithms.

The authors have been developing human-like head robots in order to develop new head mechanisms and functions for a humanoid robot that has the ability to communicate naturally with a human by expressing human-like emotion. Furthermore, the interaction between humans and robots is one of the essential factors for the Neuro-Robotics. We believed that the Mental Dynamics caused by the stimuli from the internal and external environment is important in expressing emotion. Therefore, we newly developed a human-like head robot WE-4 (Waseda Eye No.4) in 2002. The "Learning System", the "Mood Vector" and the "Second Order Equations of Emotion" were introduced to the mental model of the robot. Moreover, an internal clock was introduced as an autonomic nerve system to express the activation component of the Mood Vector. And, we realized the expression of mental transition caused by the stimuli from the internal and external environment of the robot. In this paper, we describe the new mental model of a human-like head robot WE-4.

This paper describes a jaw movement training robot system implementing a 6 degrees of freedom (DOF) parallel mechanism, and its application for lateral movement raining. Temporomandibular joints (TMJ) problem is a disorder, whereby patients are not able to open their mouths nor move their jaws easily because of the problems with the mandibular joints, mastication muscles, and other organs concerning food chewing. Conventional therapy has been done with simple mouth opening apparatuses based on a doctor's technique through their own experiences, while this is still common. The authors have developed and improved a jaw movement training robot system, which provides not only jaw open and close training but also consists of a 6-DOF slave manipulator as a patient working manipulator and a 3-DOF master manipulator as a doctor commanding manipulator.

The authors have been developing human-like head robots in order to develop new head mechanisms and functions for a humanoid robot that has the ability to communicate naturally with a human by expressing human-like emotion. We believe that in the future, it will be necessary for personal robots to generate active behavior to interact bilaterally between human and robot. Therefore, we developed an emotion expression humanoid robot WE-4R (Waseda eye no.4 refined) in 2003. The need model consisting of the "appetite," the "need for security" and the "need for exploration" was introduced to the mental model for humanoid robots. We also defined the "need matrix" and introduced the "equations of need" to describe the robot needs. Robots with the need model can generate and express active behavior according to their need. This paper describes the need model that is implemented in the emotion expression humanoid robot WE-4R.

This paper describes the development of a new talking robot WT-2 that improved on WT-1R and has advanced vocal tract mechanisms for the reproduction of human vocal movement. WT-2 consists lungs, vocal cords, a vocal cavity and nasal cavity; the total DOF is 15. The length of the vocal tract is about 175 mm and is almost the same as that of an adult male. Compared to WT-1 or WT-1R developed previously, WT-2 could utter Japanese vowels more clearly, and produce stops, fricatives and nasal sounds by a new flexible tongue mechanism as well as decrease sound leaks from the tongue except those from the lips or nostrils.

This paper describes the modeling and analysis of an elastic tongue mechanism of a talking robot WT-2 and the development of an acoustic simulator for the construction of the computational model of human speech production. WT-2 consists of lungs, vocal cords and articulators. It is essential to accurately estimate and analyze the shapes of these organs to develop an acoustic simulator. However, it was difficult to estimate and analyze the mechanisms, because they were composed of an elastic rubber to make various shapes and to seal the air and sound. Therefore, we constructed a modeling method to simulate the shape of the elastic mechanisms. This method is applicable to all the elastic body. We developed an acoustic simulator using this modeling method in the process of constructing the speech production model.

This paper describes the speech planning of the anthropomorphic talking robot WT-1R (Waseda Talker-No.1 Refined) for the production of consonant sounds. WT-1R has articulators (the tongue, lips, teeth, nasal cavity and soft palate) and vocal organs (the lungs and vocal cords), and can reproduce human vocal movement. Its total DOF (degrees of freedom) is 15. The vocal movement of WT-1R for vowels is steady. We produced Japanese vowels (/a/, /i/, /u/, /e/, /o/) using the first robot WT-1 in 2000. However, the vocal movement for consonant sounds is transient. We must control the 15-DOF talking robot coordinately in the space and time to reproduce the complicated phenomena of the consonant sounds. Therefore, because the Japanese voice generally consists of two phonemes of the first consonant sound and the last vowel, we proposed the speech planning of WT-1R by considering the phenomenon of the voice as three parts (steady consonant sound, transient consonant sound and vowel). WT-1R could produce Japanese vowels (/a/, /i/, /u/, /e/, /o/) and some consonant sounds (/s/, /h/, /m/, /p/ and /waseda/).

Conventional medical/dental systems have developed only doctor or patient models. However, two models are needed to quantify the dental/medical therapy; these are the patient model and the doctor model. The authors focus on the mouth opening and closing training done for the patients who have disorders on their jaw joints. The mastication robot as a patient model and the mouth opening-closing training robot as a doctor model are developed. The paper describes two robots that quantitatively evaluate the mouth opening and closing training. Force data using these two robots showed that robot training's force acting on the patient is smaller than the conventional training using a wooden device.

The authors have been developing human-like head robots in order to develop new head mechanisms and functions for a humanoid robot that has the ability to communicate naturally with a human by expressing human-like emotion. We were able to simulate four sensations (the visual, auditory, cutaneous and olfactory sensations) of a human five senses by developing WE-3 (W_aseda E_ye No.3_) series since 1995. However, the robot system of WE-3 has become too complex and big from added improvements. Therefore, in 2002, we developed a new human-like head robot WE-4 (W_aseda E_ye No. 4_). We newly added a waist to WE-4, and realized emotional expression with not only the face, but also the upper-half part of the robot body. Also, WE-4 is smaller and lighter from revisions in mechanisms of the robot head In this paper we describe the mechanical features of the human-like head robot WE-4.

This paper describes the 6-degrees of freedom (6-DOF) jaw training robot that manipulates the patient's jaw to move sideway. Patients with jaw disorders who can not only control the opening/closing of their jaws, but also sideway movements are the target of this research. The authors developed a 6-DOF slave manipulator and 3-DOF master manipulator for these patients. The natural jaw's sideway motion was simulated by changing the center of rotation according to the rotational direction of the mandible. A real training for a jaw disorder patient using the robot was done, and the resulting distance to sideway was increased 9 to 15 mm in the right jaw joint and 7 to 12 mm in the left.

The authors have been developing new head mechanisms and functions for a humanoid robot that has the ability to communicate naturally with a human by expressing human-like emotion. In this paper, they focus on the olfactory sensation and facial color that humans use to communicate with each other. Human's olfactory sensation recognizes over thousand different smells. The WE-3RIV (Waseda eye No.3 refined IV) developed can recognize the smell of alcohol, ammonia and cigarette smoke. The olfactory sensor consists of four semiconductor gas sensors. WE-3RIV is able to recognize certain smells within a few seconds of being presented with the smell stimuli by using the sensor output and the rate of changing of output. Further, we developed the facial color expression using red electro-luminescent sheets. By adding the facial color expression, the expressiveness of the robot and its facial expression are improved.

The authors deal with human-like head robots in order to develop new head mechanisms and functions for a humanoid robot that has the ability to communicate naturally with a human by expressing human-like emotion. When humans communicate through auditory or visual sensations, they estimate their mental state through not only the information of each sensation but also their mental model. A robot's mental model consists of a 3D mental space having a pleasantness, and activation and a certainty axes. When the robot senses the stimulus, a mental vector moves in this mental space based on the equations of emotion. We also propose a robot personality which consists of sensing personality and expression personality. Further, we assign and load various sensing personalities.

Vocal movement is not only a movement of the vocal organs, it is also a movement that produces acoustic signals received by hearing as linguistic information through hydroacoustic phenomena along with the formation of the vocal way. The purpose of this research is to study the human vocal mechanism from the engineering point of view by simulating the vocal movement with a robot, and to create the dynamic model. The authors developed an anthropomorphic talking robot WT-1 (Waseda Talker-No.1) in 1999. It simulates human vocal movement, and has articulators (a 6-DOF tongue, 4-DOF lips, 1-DOF teeth, a nasal cavity and 1-DOF soft palate) and vocal organs (1-DOF lungs and 1-DOF vocal cords); the total DOF of the robot is 14. We experimented with it on Japanese vowels. However, the voice produced was not natural. In this paper we describe an improvement of the mechanisms for the realization of natural vowels and consonant sounds.

The authors have been developing human-like head robots in order to develop new head mechanisms and functions for a humanoid robot that has the ability to communicate naturally with a human by expressing human-like emotions. We think that the personality of the robot is extremely important in attaining smooth and effective communication. We introduced a robot personality that consists of the sensing personality and the expression personality. The sensing personality determines how a stimulus works for a robot's mental state. A 3D mental space was defined in the robot. Seven emotions were mapped out in the 3D mental space. After the robot determines its emotion, it expresses its emotion by the expression personality. We expressed the expression personality using a matrix. Moreover, we assigned and loaded six robot personalities into the robot. The robot can express various personalities.

This research attempts to clarify the human vocal mechanism from engineering viewpoints by simulating the vocal movement with a robot, and to create a dynamic model. The authors developed an anthropomorphic talking robot, WT-1 (Waseda Talker-No.1) in 1999. It simulated the human vocal movement,. and had articulators and vocal organs. WT-1 could speak Japanese vowels (|a|, |i|, |u|, |e|, |o|). However, the vowels produced were not natural. Therefore, we develop a refined talking robot WT-1R that improves the realization of natural vowels and consonant sounds. WT-IR has articulators (the 6-DOF tongue, 4-DOF lips, 1-DOF teeth, a nasal cavity and a 1-DOF soft palate) and vocal organs (the 1-DOF lungs, 2-DOF vocal cords). The total DOF of the robot is 15. This paper describes the improved mechanisms of WT-IR and the realization of the fluctuation for the natural voice and the clearness of vowels.

Describes a skull robot as a patient simulator for mouth opening and closing training. The rehabilitation for patients who have problems on the jaw joint have been done primarily based on the doctor's qualitative experience and technique that is unknown to other people. The authors developed a skull robot WOJ-1R as a mechanical patient simulator This skull robot will be useful for the doctor to develop the strategy of training for the real human patient. Also, it will quantitatively clarify the effectiveness of the robots therapy compared with therapy by human. Experimental results of biting force comparison show that robot therapy force data acting on the skull robot was smaller than the conventional therapy by human.

This paper describes the remote training between Tokyo and Yamanashi with 6 degrees of freedom (DOF) parallel robot that is designed for the mouth-opening and -closing training. Remote training is useful for the patients who have difficulties to go to hospitals frequently. The authors have developed a master-slave training system using ISDN lines because ISDN is not difficult to come by in patients home. Mouth-opening and -closing training robot WY-5R (Waseda Yamanashi-5 Refined) realized the remote training via two ISDN lines with 128 kbps. As a result of remote therapy using WY-5R, two patients' mouth-opening and -forward distances increased.

The authors have been developing anthropomorphic head-eye robots, in order to elucidate the human vision system from an engineering point of view, and to develop a new head mechanism and function for a humanoid robot having the ability to communicate naturally with a human. We developed an anthropomorphic head-eye robot "WE-3R III" (Waseda Eye No.3 Refined III) having auditory sensation, cutaneous sensation and a facial expression mechanism with eyes, eyelids, eyebrows, lips, a jaw and a neck. It is said that the human cutaneous sensations include contact, pressure, cold, warmth and pain, so a tactile sensor and a temperature sensor were mounted on the robot. For the tactile sensor, we adopted a force sensing resistor. We think that the difference in touching methods such as 'push', 'stroke' and 'hit' have an effect on emotion, therefore we developed the method for recognizing those differences, and installed it in the robot. By improving and rebuilding the artificial psychological model of WE-3RII using a new concept-equations of emotion-in a 3D mental space, we realized expression of the mental state affected by various stimuli with WE-3R III.

This paper describes a 6 degrees freedom (DOF) parallel robot that is designed for the mouth opening and closing training. The rehabilitation for the patient who have problems on the jaw joint, mastication muscles, and other organs concerning the food chewing have been done primarily based on the doctor's technique. Conventional mouth opening apparatuses (such as wooden screws, bite blocks and clothespins-type apparatus) only increases mouth opening distance and do not have actuators, sensors, and/or control systems. Moreover, during therapy, the quantitative force data is unknown in spite of its importance for the standardization of mouth opening and closing training. Mouth opening and closing training robot WY-5 (Waseda Yamanashi No. 5) consists of mechanical, actuation, sensor and control systems. As a result of therapy using WY-5, the mouth opening distance increased.

The authors have been developing anthropomorphic head robots in order to develop a new head mechanisms and functions for a humanoid robot having the ability to communicate naturally with a human by expressing human like emotion. We developed the anthropomorphic head-eye robot "WE-3RIV" (Waseda Eye No.3 Refined IV) which has four sensations and facially expresses emotions in 2000. We have recently added the olfactory sensation and the facial color expression function to its previous model, WE-3RIII, and we improved and rebuilt its artificial psychological model that consists of a 3D mental space having pleasantness, activation and certainty axes. When the robot senses the stimulus, a mental vector moves in the mental space based upon a set of differential equations in the mathematical formulation. We named it "equations of emotion. " We also introduced the robot personality, which consists of the sensing personality and the expression personality. WE-3RIV was realized to express the mental state affected by various stimuli based on the equations of emotion and the robot personality.

The vocal movement isn't only a movement of the vocal organs. It is also a movement that produces acoustic signals received by hearing as linguistic information through hydroacoustic phenomena along with the formation of the vocal way. The purpose of this research is to make clear human vocal mechanism from the view of engineering by reproducing the vocal movement using a robot, and to make the dynamic model. Therefore, the authors developed an anthropomorphic talking robot, WT-1 (Waseda Talker-No.1). It simulates human voice movement, and has articulators (the 4-DOF lips, 1-DOF teeth, 6-DOF tongue, nasal cavity and 1-DOF soft palate) and the vocal organs (the 1-DOF vocal cords, 1-DOF lungs); Total DOF of the robot is 14.

Describes remote training with a 6-degrees-of-freedom (DOF) parallel robot that is designed for training patients in mouth opening and closing. Rehabilitation for patients who have problems with their jaw joint, mastication muscles or other organs concerned with chewing food has been done primarily based on their doctor's qualitative experience and technique. Conventional mouth-opening apparatus (such as wooden screws, bite blocks and clothes-pin-type apparatus) only increases the mouth-opening distance and does not have any actuators, sensors and/or control systems. Moreover, during therapy, the quantitative data is unknown, inspite of its importance for the standardization of mouth-opening/closing training. The mouth-opening/closing training robot WY-5R (Wadaseda Yamanashi-5 Refined) realized the remote training via an ISDN line. As a result of remote therapy using WY-5R, the patient's mouth-opening distance increased.

The authors have been developing anthropomorphic head-eye robots, in order to elucidate the human vision system from an engineering point of view, and to develop a new head mechanism and function for a humanoid robot having the ability to communicate naturally with a human. We developed the anthropomorphic head-eye robot "WE-3RII" (Waseda Eye No.3 Refined II), with eyes, eyelids, eyebrows, lips, jaw and a neck. The robot has the ability to express an autonomous facial expression using three independent parameters of a psychological model. With the robot, the mechanism of changing eye movement from smooth pursuit eye movement to saccadic, and the control of scanning eye movement like that of a human's can be achieved. The robot is also able to express more human-like motion in pursuing a target by changing its eyeball control parameters, rather than that of WE-3R which we developed in 1996. Therefore, the authors have confirmed that WE-3RII has the ability to realize a pursuing motion in three dimensional space with its autonomous facial expression adapting to the target position and brightness like a human.

Describes the development of a mouth-opening and -closing training robot WY-3 (Waseda Yamanashi-3) that has been designed and developed by combining oral-maxillofacial surgery and robotics. Mouth-opening training is useful for the rehabilitation of patients who have problems opening and closing their mouths. Conventional mouth-opening apparatus (such as wooden screws, bite blocks and clothespins type apparatus) only increase mouth-opening distance and do not have actuators, sensors, and/or control systems. Moreover, during therapy the quantitative force data is unknown in spite of its importance for the standardization of mouth-opening and -closing training. The mouth-opening and -closing training robot WY-3 consists of mechanical, actuation, sensor, and control systems. As a result of therapy using WY-3, the mouth-opening distance increased from 36 to 41 mm.

This paper describes the quantification of masticatory efficiency by using a mastication robot that was developed as a mechanical simulator of human masticatory jaw motion on the basis of dental robotics. The masticatory efficiency is evaluated on the basis of human mastication and the quantification of masticatory efficiency is studied experimentally. In this paper, the authors use the sifting test to quantify efficiency. The results of chewing experiments with robot by comparing the differences in chewing motion between clenching and grinding showed that the masticatory efficiency of the latter was higher than that of the former.

This paper describes the mathematical and mechanical models that simulate the nonlinearity of human's masticatory muscle. In addition, the experimental results of a real food chewing experiment by a mastication robot is described. When the lower jaw rapidly closes during the chewing motion, it may come in hard contact with the upper jaw if the food is a crushable one. To clarify the mechanism of this reflective jaw motion, the authors focused on the nonlinearity of human's masticatory muscle. The authors propose a feasible mathematical model of the muscle and its nonlinearity. A nonlinear viscoelastic mechanism is designed based on the mathematical model. From the result of chewing experiment, the authors confirmed the effectiveness of the proposed mechanism for the control of the robot jaw.

Describes mathematical models that simulate the nonlinearity of the human muscle, and the results of a real food chewing experiment by a mastication robot. When the lower jaw rapidly closes, it may come in hard contact with the upper jaw if the food is a crushable one. To clarify the mechanism of rapid jaw motion, the authors focused on the nonlinearity of the human muscle that is known in the field of the physiology or biomechanisms. The authors propose a feasible mathematical model for the muscle and its nonlinearity. A nonlinear spring mechanism is then designed based on the mathematical model. As a result of chewing experiment, the authors confirmed control of the rapid closing motion of the robot jaw using the nonlinear spring mechanism. This work was done as part of the "Humanoid Project" at HUREL (Humanoid Research Laboratory).

A mastication robot is a jaw motion simulator that has similar structure and function to the human masticatory system. This paper describes an optimal reduction of the jaw joint force focusing on the fan shape of the musculus temporalis (M.temporalis) spreading around the side of skull. The shape of M.temporalis is simplified as two independent lines, and the jaw joint force is computed by using linear programming. Furthermore the actuators corresponding to the anterior and posterior parts of M.temporalis are assigned separately. The 28% reduction of jaw joint force was confirmed experimentally by using robot.>

This paper describes a mechanism for a mastication robot using a human skull model. Since 1986 the authors have been developing the WJ (Waseda Jaw) series of mastication robots by using a dental study model, a duralumin mandibular, DC motors, wires, etc. From 1986 to 1991 the authors developed mastication robots with a mechanical mandibular model, and experimented with these robots. However, in order to analyze the human masticatory system, the authors needed a model closer to the human. The characteristics of the new mastication robot mechanism developed in 1992 are, that this robot has a structure similar to the human by using a skull model and, that the argument of the temporalis muscle force vector is variable by using two actuators. On the basis of this robot, the authors will be able to clarify and construct a quantitative and dynamic masticatory model for human mastication because it has human-like structures.