Some studies have reported that movements of forearm and wrist has several rolls to perform a baseball pitching. However dynamical mechanism of the forearm and the wrist are still unclear. As a step toward understanding the rolls of forearm and hand in baseball pitching, we investigated how non-muscular (e.g. centrifugal. Coriolis, and gravity) forces of the each link generates, absorbs, and transfers mechanical energy in order to produce maximum velocity. This was accomplished using multi-body power analysis derived entirely from dynamical equations of a 3D double pendulum with moving pivot model. In order to analyze based on this model, collegiate male baseball pitchier arm movements were captured by motion capture system with IkHz sampling. The analysis clarified that mechanical energy of the hand segment was transferred through internal force which was mainly dominated by centrifugal force, although muscle torque applied to the wrist joint absorbed the mechanical energy of the hand segment rather than increasing the energy.

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The mechanism of hammer head acceleration was understood by a simulation based on a parametric excitation of its handle movement. It was also important for this simulation to adjust initial conditions of differential equations at the start of first turn after preliminary winds. Head speed fluctuation per turn was basically determined by a principle of a parametric excitation from first turn to fourth turn, especially head speed increment was resulted from the accumulation of more positive power translated into the head through its handle and wire during delivery phase. If negative work which caused decrease of head speed was done with a little decreasing wire tensile force during single support phase of fourth turn, some reserves up to the maximum wire tensile force or handle power in actual throwing would augment release speed during delivery phase.

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This study aims to reveal the effect on motion and ground reaction force of presence of selective reaction in changing direction while running. The participants were instructed to make directional changes on a force plate on two conditions (With an advance instructions, or without). The motion was then studied by using three-dimensional motion analysis and force plate data. According to the results, the average value of all subjects had no significant trend. On the other hand, there are individual differences in the effect of giving instruction before trial Thus, that made difficult to see a clear trend in all subjects by these variations affect each other.

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The purpose of this study is to develop an instruction system for supporting to inherit skills on buffing process. As the first step, the technical characteristics of skilled worker were investigated in order to find the effective information for instructing to unskilled person or trainees in this system. Polishing load and relative rotation/translation between workpiece and buff were measured simultaneously by using 3-component load-cells and a motion capture system. Contact states between workpiece and buff were estimated from these data, and then compared with skilled and unskilled workers. During buffing, cyclic movement of workpiece to sideward direction was observed by each subject; however, it was found that the fluctuations of vertical polishing load and workpiece tilt per cycle obtained by skilled subject were significantly smaller than unskilled subjects.

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Kyudo is a competition which applies an arrow on a target, and a series of operations which shoot an arrow are important. This study will focus on one of their drawing motion. Draw become different a school and by individual physique and thought, but it is not analyzed numerically, and almost of the experience to know what the athlete. In this study, consider the optimization of drawing motion for multipurpose genetic algorithm. We analyzed from the perspective of the forward dynamics, using a human and bow model of Japanese archery for even large deformation beam and the rigid link.

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Pole vaulting is a sport in which an athlete clears the highest jump heights achievable in a competition. Pole vaulting has progressed rapidly in terms of improved mechanical properties and better appearance by using poles made of flexible fiberglass material. Competitive pole vaulting requires specific characteristics that promote higher jumps. In this research, dynamic analysis using a spring mass pole model of three-dimensional. Spring mass pole model are composed of particle, structural springs and shear springs. Pole deformation at the time of changing a spring constant is investigated. From the results, optimization of the pole characteristic in the pole vault using spring mass pole model is considered.

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The purpose of this study was to propose a simulation method for pole vault jump motion to reduce computing time compared to conventional pole vault simulation. The whole-body was modeled as a virtual rigid body, and the pole was modeled as rigid bodies connecting to its adjacent segments with rotary spring elements. The equation of motion of the virtual rigid body was derived under the condition where the forces exerting on the pole grip act on each hand. An equivalent stifmess matrix at grip-end of pole was derived from the joint stifmess matrix to calculate pole reaction force and moment exerted on the virtual rigid body as the external force and moment.

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This paper deals with an analysis of a double leg circle of a side horse exercise in gymnastics performed by two gymnasts who are different in the level of performance quality. Two different types of the circle were performed: one was a circle keeping a gravitational center of the body at a higher position and the other was a kind of conventional circle. We obtained three-dimensional position data using 35 markers attached to the player's body, and detected muscle activity using 16 sensors. From the analysis of the data, we concluded that (1) Deltoideus Pars and Triceps Brachii Capt are the essential muscles to perform a circle. (2) In the performance of a circle keeping gravitational center at a higher position, the activities of Rectus Femoris, and Obliquus Externus Abdominis were detected. (3) Training for a quick twisting motion of hips is the key to the effective performance of a circle.

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The purpose of this paper is to discuss the relation between interactivity and the degree of KAWAII for characters. It is also our problems that whence comes the 'KAWAII, fun' or 'amiability' of a 'character'? It is shown that we propose the visual communication model from the Shannon and Weaver process model of communication, and the interaction exists between the character and the audience. The element that can decide the interactive degree of the character shows the relation to the story that the character has. Interest appears as a result of interactivity of characters. It is also shown that KAWAII proposes to appear as a function of interactivity.

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It is important to evaluate the performance of shoes functions, including fitting, shock-absorbing, and stability. Especially, shoe fitting is one of the most significant factors because it profoundly influences other factors. In previous studies, after each shape of feet and shoes was measured separately by using three-dimensional measurement device, these data were superimposed in computer and shoe fitting was evaluated in virtual space and thus the deformation of feet when wearing shoes was not taken into consideration. To solve this problem, we investigated shoe fitting by using MRI to take feet images when wearing shoes and constructed three-dimensional foot models. We could observe the deformation of feet when wearing shoes by using MRI, and there was relationship between the deformation of feet and results of sensory test for shoe fitting when wearing shoes.

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It is known that the golden and silver ratios of about 1:1.5 give the human brains comfort. Then, there is also the symmetric ratio of 1:1 in ORIGAMI. The present report clarifies the reason why the human beings feel comfort in these ratios. Moreover, we find the aqua ratios for inducing well-being in the human brains, which also include the ratios around the golden and silver ones. Actual experimental data on the brains gives an evidence for the relation between feeling of comfort and brain structure.

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Based on the results of psychological evaluation by Iyashi measuring system, we try to make clear the Iyashi structure for each person. From 20 face images used in the system the factors by which the subjects judge "iyashi" and "non-iyashi" are extracted. Then, the correlation of the judgment results among the attributes such as age and sex and the influence which each part efface has on the judgment are analyzed.

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Kansei design of comfortable and beautiful tableware for camping, traveling, and picnics is the interesting task. This tableware should be light, compact and convenient. In this paper, we suggest to use origami-based approach for designing this kinds of tableware. Cylindrical origami structure is used for creating the patterns for the tableware design. By changing the shape of bottom polygon and angles of folding lines, the different designs are created. Patterns for creating the different model shapes are constructed by applying software "ORIPA". For 3D simulation "Freeform Origami" software is used.

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The new NPB Ball was adapted to the Japanese NPB from this year. Compared with the old NPB ball and new one, seem height and width became 0.2[mm] lower and 1.0[mm] wider respectively. In this report, aerodynamics characteristics are measured by using wind tunnel tests. Some calculations of flight trajectory for pitcher's throwing ball and batter's hitting one are conducted.

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We investigate the maximum projection angle of a ball acting on drag and lift with constant coefficients. The equation of motion for a particle with drag and lift proportional to the speed is derived from that with the quadratic law of drag and lift. The linearized equation provides the second order perturbed solution of the maximum projection angle. Comparing the perturbed solution with numerical ones obtained from the equation with the quadratic drag and lift, the following results are obtained. (1) Both the drag and lift decrease the maximum projection angle. (2) The decrease due to lift is stronger than that due to drag. (3) The maximum projection angle has a concave curve according to drag while it has a convex shape for lift. (4) The second-order formula of drag and lift gives a good approximation to the maximum projection angle.

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The aerodynamic forces acting on a discus were measured by wind tunnel tests, and the optimization study on discus throw was carried out by using a genetic algorithm. It was found that the stalling angle is about 30°, and the higher the spin rate the smaller the stalling angle. From the optimization study, it was revealed that the spin rate on its transverse axis should be maximized, and the angle of attack should increase from the negative value to the positive value with increasing time. The absolute value of the angle of attack should be less than the stalling angle during the whole flight.

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The purpose of this paper was to clarify the effect of the arms position on the aerodynamic forces and moment during the early flight phase in ski jumping. The early flight phase is defined as 0.4 to 0.5 seconds after the take-off. We studied the aerodynamic effect caused by the arms positions during early flight phase by wind tunnel experiments and computer simulation. The results showed that the arms raised backward position during the early flight phase produced less lift and more nose-down pitching moment than the arms fitted to trunk position did. In the early flight phase, the arms fitted to trunk position could be more effective style than the arms raised backward position in terms of aerodynamics point of view.

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Unicycle is dynamically unstable system. However, Human can stabilize posture of unicycle. It is difficult to clarify control algorithm. Therefore, the purpose of this study is to develop a unicycle robot for emulating a human riding behavior and to stabilize posture of the unicycle robot. From the unicycle riding experiment of a human, pitching moment, rolling moment, yawing moment that generated by pedal control known to be exerted influence by posture angle of unicycle. However, control algorithm remains to be elucidated. We manufactured unicycle robot recreating pedal motion of a human. This paper reports on result of pitch angle control as initial stage of our work.

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We have formulated a successive three-link and three-joint optimal control model that reproduces human squat movements. The model successively optimizes the half-crouching process and the rising-up process of squat movements, and its criterion function consists of three kinds of energy costs, an center-of-gravity cost, and an input (torque-change) cost. We clarify its fundamental performance and factors indispensable for reproducing the same squat movements as humans. Consequently, the following results were obtained: (1) experimentally measured squat movements were successfully reproduced by appropriately adjusting the switching time when the half-crouching process ends and the rising-up process starts; (2) the energy costs and the center-of-gravity cost hardly affected the model's performance; (3) there existed the optimum switching time for each squat condition. These results suggest that the proposed model is effective as a model of the human squatting mechanism and that the switching time can be a factor involved strongly in human squat movements.

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The modeling of human/machine interaction involves both the dynamics of human response to achieve task demand and the machine compensation dynamics acquired in advance by hard practice in the machine control. This paper presents the human motion model x" = a - Cx' to achieve task demands derived from Weber's Law of stimulus/response and the human motion control model consisting of the human motion model x" = a - Cx' and the inverse model of the target machine and it can apply broadly ranging from control of cars, aircrafts, ships and spaceships. As a control example, the model controls an instability vehicle maintaining desired high cornering acceleration under large slip angle run in a fully nonlinear vehicle computer simulation of CarSim with MATLAB/Simulink.

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We discuss a new optimal control model for human arm's via-point movements from the viewpoint that human arm's reaching movements are produced based on the cooperative relation between the human vision system and the arm control mechanism. The cooperative relation is clarified by deriving two kinds of reaction time of the eye-movement and arm control mechanisms during two-point reaching movements and via-point movements. Consequently, the following results were obtained: (1) for the two-point reaching movements, the reaction time for the eye-movement mechanism was shorter than that for the arm control mechanism; (2) for the via-point movements, the relation of reaction time between the two mechanisms was the same as in the result (1) in the two kinds of half movements divided by the via-point. These mean that the human vision system acquires the position information of the via-point and the target through its eye-movement, and the arm moves after the eye-movement. The results suggest the possibility of a successive two-point reaching movement model that successively reproduces two kinds of two-point reaching movements divided by the via-point.

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Wearable technology has been advanced for the purpose of physiological monitoring system during daily life. In measuring ground reaction force, the method to estimate plantar pressure from output of compact force sensors on the insole in shoe has been used. However, compact sensors which are used in the method is expensive, it is hard to use the sensors in daily monitoring of sports activity and rehabilitation. In this paper, we have made wearable plantar pressure measuring device which adapted inexpensive thin-film force sensors instead of compact sensors. To evaluate the usefulness of this measuring device, we have measured planter pressure with 5 different cadence and estimated ground reaction force.

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This paper proposes the measurement method of 3D orientation using inertial sensors. The method estimates the SDorientation of the local coordination by inertial sensors attached to the two link body segment. The sensor fusion that is established in this study estimate 3D orientation compensated drift error of gyro sensor output by translational and gravity acceleration of accelerometer output. The nonlinear state equation in the sensor fusion can estimate 3D orientation (Roll-Pitch-Yaw angle) by applying to extended Kalman filter. In order to indicate the performance of the proposed method, we have conducted the experiment to confirm precision of the proposed method using the system installed the rotary encoder. As the result, the proposed methods have estimated 3D orientation compensated drift error of gyro sensor output. The result of method by unscented Kalman filter has indicated higher precision than the result of method by extended Kalman filter. The proposed method can be used to the orientation measurement in various motions.

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