Shoichiro Takehara

A mobility system named TSMD has been proposed as new moving means under microgravity such as outer space. By winding tether that was extension, TSMD cause to move human. In this system that extend and wind tether under microgravity such as TSMD, contact force between the tether and the rigid body is expected to influence the motion of the system. Therefore, in this paper, the influence of contact force between a flexible body (tether) and slit that has elastic wall (outlet and inlet of tether) that gives the motion of the system is analyzed. The analytical model of the TSMD that moves in a two-dimensional plane was made and was simulated by changing the slit shape using this model. As a result, it was confirmed that the attitude control method focusing on rotational energy was effective under all conditions in which the shape of the slit at inlet was changed. In addition, it was confirmed that the shape of the slit affects the responsiveness of the control effect. Moreover, it was found that there are suitable slit shape that improves the responsiveness of the control effect.

The purpose of this paper is to build a selection index for tennis rackets. By investigating the effect of the racket on its stroke motion, derived motion indices were used to evaluate the tennis racket. During its swing, the feature points of the motion are derived by calculating the contribution of each part of the body in the tennis stroke motion, and the analysis is performed focusing on the feature points. The subjects of the study were three male senior tennis players and two male beginner players. Stroke motion and the three-dimensional information of each part of the human body was recorded with twelve motion capture cameras and six rackets with different characteristics. By using three-dimensional information, characteristic markers of the tennis strokes were derived. The vertical position of the marker was analyzed, and the change in the stroke motion of each racket was examined. Focusing on the swing variation from racket to racket, the sum of standard deviations was used. The analysis was performed by comparing the sum of standard deviation and swing speed. As a result, the relationship between the sum of the standard deviation and the swing speed for the stroke motion was shown.

This paper examined the influence of the racket on tennis strokes motion. In the experiments, 13 male subjects hit the balls with four kinds of rackets, and the tennis stroke was recorded and digitized by twelve motion capture cameras. After that, using three-dimensional coordinate value of the body, the contribution of the segments to the velocity of racket head was calculated to derive the distinctive marker of the body in the tennis strokes. The position in the vertical direction of the marker was analyzed, and the changes of the stroke motion using each rackets were examined. As a result, an index of tennis stroke motion was derived.

This paper examined the KANSEI evaluation of racket during tennis strokes. To analyze it, questionnaires of SD method on rackets were taken to 12 subjects after actual tennis strokes, and psychological estimations were gotten. Using them, analyses of radar chart, cluster analyses, and principal component analyses were taken. At the same time, the motions of tennis strokes were measured and digitized using the 12 motion capture devices and were compared with psychological estimations. At first, personal preferences were charted. Secondly, subjects were classified into the three groups of experienced persons and the one group of novices from result of cluster analysis. Thirdly, experienced persons emphasized different evaluation factors from those of novices from result of principal component analysis. Finally, it was confirmed that the sum of the standard deviations of the locus during tennis strokes was related to the racket's comfort in experienced persons. Therefore, the results clarified the relationship between psychological estimations on tennis rackets and motion of human bodies during tennis strokes.

In this study, we proposed a new mobility device using tether under the microgravity named Tether Space Mobility Device (TSMD). TSMD is the mobility device that moves user by winding tether which is attached to the structure in the destination. However, this system has problems that TSMD user moves with rotation because the center of gravity of the user deviates from tensile line of action of tether. Therefore, we focused on winding of tether and proposed the attitude control method of TSMD with controlled winding speed. The effectiveness of winding control was inspected by the experiment. The experiment is performed in the two-dimensional microgravity environment. Winding control is that winding speed becomes slow when the acceleration of the experiment equipment exceeded the acceleration threshold. In addition, winding acceleration set small just after the experiment start. In this paper, we producted an experimental equipment that excludes the arm mechanism installed for attitude control. We examined the effectiveness of this system by experiments simulating microgravity using an experimental equipment that was smaller and lighter than conventional equipment.

In recent years, the importance of exercising habitually began to be recognized, then the number of people riding a bicycle is increasing. In such a situation, cycle trainers are popular as Equipment to ride a bicycle indoors for training. Cycle trainers that fix both wheels are widely used. Also, as cycle trainers that can ride with confidence and feel realism, front wheel fixed type have been developed. Developers are pursuing realism based on trial and error in consideration of experience about fixing method of front wheel fixed type. The design of the fixing method affects the movement of the bicycle and the human motion and is directly connected with the evaluation of the cycle trainer. Therefore it has significance that understands the relationship between the human motion and the sensibility which changes according to the fixing method of the cycle trainer. Furthermore, it is difficult to realize optimal design for each person to consider human diversity. In order to establish design guidelines on realism at the time of riding, it is necessary to understand the factors that users are evaluating and to consider the evaluation factors of cycle trainers in the design. An evaluation grid method is used to understand the user's evaluation factor. This design method is aiming at extracting the part related to evaluation from the cognitive structure of a person by the subject's own words. Questionnaires of Evaluation grid method was performed for three kinds of cycle trainers with different functions. As a result conglomerate evaluation tree was gotten.

Recently, increasing numbers of very small-sized vehicles like a personal mobility have been developed. As the mass of such small-sized vehicle is often comparable to that of their drivers, the coupling behavior between them is increasing in comparison with traditional vehicle types. Therefore, when developing small-sized vehicles, the dynamics of the human body riding inside them should be considered. In this research, a model of a human body inside a small-sized personal vehicle is proposed. However, whole body model has multiple degrees of freedom and property. Furthermore, the influence of parameters of human is uncertainty and it is difficult to set accurate parameters. Accordingly, the dynamics of only trunk of the human body on a vehicle has been studied. Thus, in order to evaluate the performance of personal mobility, vehicle-human dynamics model considering interaction is proposed. In particular, consider the influence on the vehicle design by the change of the parameter representing the reaction delay of the human body. Consequently, it is confirmed that safety is impaired in the condition that reaction delay is large. In control design of inverted pendulum type personal mobility, we found that it is necessary to consider the human control system.

This paper examined the changes of the motion during tennis stroke due to the difference of rackets. To analyze it, the actual tennis stroke using the 12 motion capture devices was measured. In the experiments, the strokes of 12 male subjects using 4 rackets were measured and were digitized. Analyzing a position in the vertical direction of each marker, the changes and characteristics of the stroke motion using each rackets were considered. At the same time, subjects answered to the questionnaires created basis on evaluation grid method. Comparing the obtained psychological evaluation with the measurement result of the motion, an indication of motion and psychology was derived. As a result, firstly, in the motion of tennis stroke, there were two characteristics by subjects. The first one was the characteristic to raise the racket during take-back operation, and nine subjects did this behavior. Another was the characteristic to lower the racket during take-back operation, and two subjects did this behavior. Secondly, it was confirmed that there were dispersions in the motion of tennis stroke using each racket. The dispersions were quantitatively expressed using the sum of the standard deviations and compared with the psychological evaluation. As a result, it was found that the sum of the standard deviations was an indication for experienced persons relating to the racket's comfort. On the other hand, it was shown that it was possible to objectively suggest the most suitable racket to not only experienced persons but also novices presenting the sum of standard deviations. Therefore, the result showed the sum of the standard deviations of the motion during tennis stroke was one indication of evaluation of rackets.

In recent years, some systems which contain a floating body, such as Unmanned Aerial Vehicle (UAV) connected with a tether, are used for transportation. However, the coupling motion of the system is not easily predicted with high accuracy and may induce instability of the floating body. Therefore, to control the system, comprehension of the motion of the whole system is of great importance to control the system. In this investigation, modeling and formulation of the tethered system which contains a floating body is presented using Absolute Nodal Coordinate Formulation (ANCF) and the result of the numerical simulation of the motion is discussed.

An increasing number of small-sized vehicles like a personal mobility are being developed these years since environmental and energy-saving performance have gained considerable importance on mobility developments. The feature of these vehicles is smaller and lighter than traditional vehicles. It is expected that motion of human body has a large influence on running performance of the vehicle, and this affects vehicle stability and human safety. This report examines interactions between a vehicle and a human from simulation results by a simulation model that consists of a vehicle model like a personal mobility and a human model that expresses human motion. It is demonstrated that interactions between the vehicle model and the human model depend on vehicle spec and mass ratio.

This study aims to create a system that can evaluate railway vehicle characteristics while simultaneously controlling human body behavior using numerical simulations. The proposed system consists of a vehicle model, a human motion generation model, and a musculoskeletal model. The vehicle model first calculates the vehicle motion in various situations and then calculates the human motion by imputing the acceleration data of the vehicle seat to the human model. At this point, the human motion is calculated by inverse and forward dynamics with a reaction force at the contact point between the human body and the seat. Finally, muscle activation and loading are calculated by inverse dynamics with the human body position, and the reaction force is determined from the above calculations. Using these data, it is possible to examine and evaluate the human body posture. Note that this paper limits discussion to the relationship between the human body motion generation and the railway vehicle. The muscle force will be left for a future study. To demonstrate the effectiveness of the human motion generation model, a simple human dummy model that consists of only a spring and damper was created. Comparing this dummy model (which simulates the experimental model used for experiments such as automobile collisions) with the human motion generation model, it can be concluded that the human motion generation model can simulate details of human motion that the simple dummy model cannot. Thus, the control system in the human motion generation model is important for human motion evaluations.

An increasing number of small-sized vehicles like a mobility scooter are being developed these years since environmental and energy- saving performance have gained considerable importance on mobility developments. When the mass of a vehicle becomes small, it is expected that motion of human body has a large influence on running performance of the vehicle, and this affects vehicle safety. Accordingly, it is important to study effects of mass ratio of a vehicle and a human on driving stability by focusing on interactions between them. This study for a personal mobility evaluation examines interactions between a vehicle and a human from simulation results by a simulation model that consists of a vehicle model like a personal mobility and a human model that expresses human motion.

In this study, we proposed a new mobility device using tether under the microgravity named Tether Space mobility Device (TSMD). TSMD is the mobility device that moves user by winding tether which is attached to the structure in the destination. We focused on winding of tether and proposed the posture control method of TSMD which combined with the winding control and the aim control. The experiment in the two-dimensional microgravity environment is performed. As a result of the experiment, it is confirmed that the proposed control methods decrease rotational motion, and it is found that they makes it possible to control posture of the system. In addition, it is found that winding control makes it possible to control posture of the system when a simulated disturbance by the moving of TSMD user act on the system.

An increasing number of small-sized vehicles like a personal mobility are being developed these years since environmental and energy saving performance have gained considerable importance on mobility developments. When the mass of a vehicle becomes small, it is expected that motion of human body has a large influence on running performance of the vehicle, and this affects vehicle safety. Accordingly, it is important to study effects of mass ratio of a vehicle and a human on driving stability by focusing on interactions between them. This study for a personal mobility evaluation examines interactions between a vehicle and a human from simulation results by a simulation model that consists of a vehicle model like a personal mobility and a human model that expresses human motion.

In this study, we proposed a new mobility device using tether under the microgravity named Tether Space mobility Device (TSMD). TSMD is the mobility device that moves user by winding tether which is attached to the structure in the destination. We focused on winding of tether and proposed the posture control method of TSMD which combined with the winding control and the arm control, the experiment in the two-dimensional microgravity environment is performed. As a result of the experiment, it is confirmed that the proposed control methods decrease rotational motion, and it is found that they makes it possible to control posture of the system.

Recently, increasing numbers of very small-sized vehicles like a personal mobility have been developed. As the mass of such small-sized vehicle is often comparable to that of their drivers, the coupling behavior between them is increasing in comparison with traditional vehicle types. Therefore, when developing small-sized vehicles, it is necessary to give ample consideration to the dynamics of the human body riding inside them. In this research, a model of a human body inside a small-sized personal vehicle is proposed. However, attempting to implement a whole body model would necessitate dealing with multiple degrees of freedom and give rise to distracting phenomena. Furthermore, the influences of human motion are uncertain and difficult to set into parameters. Accordingly, in this research, the human model is limited to the head and trunk of a human body riding inside a vehicle, and numerical simulations were used to investigate conditions that exist when lateral acceleration is applied. Then the parameters of numerical simulation is identified by Genetic Algorithm (GA). Additionally, the effect of motion control model is considered.

The purpose of this study was to quantitatively evaluate the physiological response when riding the personal mobility vehicle (PMV). To investigate the influence to the autonomic nervous activity due to the difference in the type of PMV, comparative experiments bicycle and Segway^[○!R], one of the inverted pendulum type PMV, have been carried out. The indices of autonomic nervous activity were calculated from the power spectrum, obtained by heart rate variability analysis. The Visual analog scale (VAS) as a sensory tests were also conducted for the 4 items (fun, fear, excitement, relax) and the correlation between the autonomic nervous activity index and the results of the VAS were examined. As a result, in the sympathetic nerve activity, a significant difference was found between the two, 1.73 times greater than that of the bicycle while riding activity indexes of the sympathetic nervous system when riding Segway. On the other hand, a significant difference between the two for the parasympathetic activity was not found. For the four items of sensory test, significant differences were observed in items other than relax, Segway was above all. However strong correlation with sympathetic nerve activity was not observed in any item.

Recently, in human centered design of the car seat, it is needed that mutual cooperative relationship based on principle and structure of human-machine system dynamics has been analyzed by the experimental results and this technique is applied to the methodology for the automobile design. However, these topics have been studied for only vibration measurement in a steady state and studies to analyze human body behavior in practical lateral-directional transient acceleration have not been performed yet. The purpose of this study is to simulate biomechanical body behavior of vehicle occupant in lateral-directional transient acceleration. The proposed experimental device has characteristics of low cost and simplicity of use. Used experimental device is composed of the carriage, the car seat, rubber band, cushion, motion capture system and mobile force plate. In this paper, the seated body behavior with lateral-directional acceleration is simulated. Moreover, each joint angle and each ground reaction moment through the experiments are calculated and quantitatively evaluated by using this experimental device and singular value decomposition. As a result of the experiments, the patterns of each movement in lateral-directional transient acceleration are obtained as the remarkably different feature quantities because the influence of the lateral-directional acceleration on human body and the characteristic behavior of the human body are shown. Finally, the effectiveness of the proposed measurement technique and method to analyze biomechanical behavior of vehicle occupant during lateral-directional transient motion on the car seat and its quantitative evaluation based on singular value decomposition of those data are validated.

Recently, increasing numbers of very small-sized vehicles like a personal mobility have been developed. As the mass of such small-sized vehicle is often comparable to that of their drivers, the coupling behavior between them is increasing in comparison with traditional vehicle types. Therefore, when developing small-sized vehicles, it is necessary to give ample consideration to the dynamics of the human body riding inside them. In this research, a model of a human body inside a small-sized personal vehicle is proposed. However, attempting to implement a whole body model would necessitate dealing with multiple degrees of freedom and give rise to distracting phenomena. Furthermore, the influences of human motion are uncertain and difficult to set into parameters. Accordingly, in this research, the human model is limited to the head and trunk of a human body riding inside a vehicle, and numerical simulations were used to investigate conditions that exist when lateral acceleration is applied. Then the parameters of numerical simulation is identified by Genetic Algorithm (GA). Additionally, the influence of human behavior parameters is considered.

Recently, increasing numbers of very small-sized automobiles like a personal vehicle have been developed. As the mass of such small-sized vehicles is often comparable to that of their drivers, the coupling motions between them is increasing in comparison with traditional vehicle types. Therefore, when developing small-sized vehicles, it is necessary to give ample consideration to the dynamics of the human body riding inside them. In this research, a model of a human body inside a small-sized personal vehicle is proposed. However, attempting to implement a whole body model would necessitate dealing with multiple degrees of freedom and give rise to distracting phenomena. Furthermore, the influences of human motion are uncertain and difficult to set into parameters. Accordingly, in this research, the human model is limited to the head and trunk of a human body riding inside a vehicle, and numerical simulations were used to investigate conditions that exist when lateral acceleration is applied. Additionally, the influence of human behavior parameters is considered.

For comfortable vehicle design, understanding the body behavior of the occupant is important. The purpose of this study was to quantify the motion response of the body to transient lateral acceleration input. In this experiment, lateral acceleration was simulated by adding the acceleration to the carriage with a fixed vehicle seat by the tension of the rubber. The body behavior at that time was measured by the force plate and motion capture system. It was confirmed that the roll angle of the head showed a large response the most, yaw angle rotation was also seen by the posture change.

With the development of computing technology in recent years, numerical simulation system is developed to calculate the body behavior on a computer. There are some advantages of applying numerical simulation in vehicle development. For example, the cost reduction, safety and easiness of changing parameters. Furthermore, development of small-sized vehicle has been investigated. As the mass of vehicle comes close to that of occupant, coupling behavior between them is increasing. Therefore, it is very important to consider dynamic property of the human body in the vehicle development. In this research, we simulate the dynamics of the human body riding on a vehicle, and we construct a system for generating the body motion. The model is optimized by applying genetic algorithm to the parameter. Moreover we modified parameter to consider the effect of analysis result.

Recently more and more small-sized vehicles like a personal vehicle have been developed. As the mass of small-sized vehicle is similar to that of driver, coupling motion between them is increasing compared with traditional type of vehicle. Therefore, it is necessary for developing small-sized vehicle to give ample consideration to the dynamics of the human body riding on a vehicle. In this research, model of the human body ridding on a vehicle is proposed. But whole body model is multiple degrees of freedom and obscurity phenomenon. Furthermore, the influence of parameters of human motion is uncertainty and it is difficult to set parameters. Therefore, in this research, human model is treated as only trunk of the human body riding on a vehicle. Then the numerical simulation is shown under the condition when lateral acceleration applied. Moreover the influence of parameter of human behavior is considered.

With the increasing use of the International Space Station, humans have more opportunities to work in outer space. In outer space, a mobility device that operates efficiently is needed. In this research, a new mobility device using tether for outer space named Tether Space Mobility Device (TSMD) is proposed. TSMD moves human by winding the tether which is attached to the wall of the structure. In this study, the numerical model of TSMD and the method of attitude control are proposed. The TSMD model is composed of three rigid bodies and one flexible body is formulated by Absolute Nodal Coordinate Formulation (ANCF). The attitude control suppresses the rotational motion of TSMD by operating the angle of the arm. In this paper, the numerical results of angular velocity with attitude control and without attitude control are compared. From the results, the attitude control is found to be effective.

The rope is used for various machines. For example, a crane is a representative machine to use rope. To use these machines more safely, it is necessary to perform the behavior analysis of the rope and pulley. Therefore the contact behavior analysis of rope and a pulley is important. In this study, numerical model is composed of a flexible body that can express motion with large deformation and large displacement. This flexible body is expressed in Absolute Nodal Coordinate Formulation (ANCF). And this model is built into normal reaction force and friction force between rope and the pulley. By performing numerical simulation, the method that demonstrates the contact between rope and pulley was confirmed. Changing the differences of quantities which added to the both edges of the rope and the coefficient of friction between rope and pulley, it is certain that the behavior of the rope has changed.

With the increasing use of the International Space Station, humans have more opportunities to work in space. In space, a mobility device that operates efficiently is needed. In this research, a mobility system called the "Tether Space Mobility Device" (TSMD) is proposed. In general, the tether is a cable or a wire rope. This system has the mechanism that uses the tether for moving. In this paper, the numerical simulation model using multibody dynamics is proposed. This numerical model is composed of two rigid bodies and one flexible body that can express motion with large deformation and large displacement. The flexible body is formulated by absolute nodal coordinate formulation. In this model, winding motion is expressed. And the experimental setup of TSMD is made. This system has arm control system and winding control system. This experimental setup can move under two-dimensional microgravity. Then, the validation of numerical simulation model is discussed.

With the development of computing technology in recent years, numerical simulation system is developed to calculate the body behavior on a computer. This technology is applied in vehicle development. More and more small-sized vehicles for small-group have been investigated. As the mass of vehicle is similar to that of occupant, coupling behavior between them is increasing. In this research, the dynamics of the human body riding on a vehicle are simulated. Then the numerical simulation is compared with experimental result under the condition when lateral acceleration applied. Moreover the influence of parameter of human behavior is considered.

We propose a mobility device using tether for human under the microgravity. This mobility device (TSMD) which makes a user moved by winding the tether, so it does not pollute air in the structure like ISS. It is advantageous to use the tether under the microgravity for its extensibility and easiness of storing. Then we have developed a prototype of TSMD and verified the availability of using the TSMD. In this paper, we improved the prototype to be able to observe its behavior against disturbance that is considering human motion. As a result of experiments to verify the effectiveness of the winding control, it was confirmed that the position control can decrease the rotation of TSMD, and in experiments input disturbance, it is found that human motion has significant influence on position control.

The rope is used for various machines. For example, a crane is a representative machine using rope. To use these machines more safely, it is necessary to analyze contact behavior between the rope and pulley. Therefore the contact behavior analysis between rope and a pulley is important. In this study, numerical model is composed of a flexible body that can express motion with large deformation and large displacement. This flexible body is expressed in Absolute Nodal Coordinate Formulation (ANCF). This model is considered for normal reaction force and friction force between rope and the pulley. By performing numerical simulation, a contact phenomenon between rope and pulley is investigated.

With the development of computing technology in recent years, numerical simulation system is developed to calculate the body behavior on a computer. There are some advantages of applying numerical simulation in vehicle development. For example, the cost reduction and safety. But the validity of numerical model needs to be shown. The experiment of human behavior was performed under stationary vibration but it does not cover the body behavior such as the movement caused by the influence of lateral acceleration that can be seen in the driving car. Furthermore, motion of body may be affected Mental Workload (MWL). In this research, we have tested experiment on the relationship between MWL and motion of body.

With the increasing use of the International Space Station, humans have more opportunities to work in outer space. In outer space, a mobility device that operates efficiently is needed. In this research, a new mobility device using tether for outer space named Tether Space Mobility Device (TSMD) is proposed. TSMD moves human by winding the tether which is attached to the wall of the structure. In this study, the numerical model of TSMD is proposed. The TSMD model is composed of three rigid bodies and one flexible body. The flexible body is formulated by absolute nodal coordinate formulation. In this paper, the numerical results of the TSMD model are compared with experimental results to investigate of the validity of proposed model. As a result of comparison between the experimental results and the analysis results, the TSMD model is found to be effective.

With the development of computing technology in recent years, numerical simulation system is developed to calculate the body behavior on a computer. There are some advantages of applying numerical simulation in vehicle development. For example, the cost reduction, safety and easiness of changing parameters. On the contrary, it is difficult to validate the numerical model. Therefore, the experiment to measure the behavior of the human body it is necessary. In this research,s fundamental experiment is performed in order to investigate the body behavior when seated in a vehicle. A fundamental experiment is performed for investigating the influence of the lateral acceleration on human body and the characteristic behavior of the human body is found.

The rope is used for various machines. For example, a crane is a representative machine to use rope. To use these machines more safely, it is necessary to perform the behavior analysis of the rope and pulley. Therefore the contact behavior analysis of rope and a pulley is important. In this study, numerical model is composed of a flexible body that can express motion with large deformation and large displacement. This flexible body is expressed in Absolute nodal coordinate formulation (ANCF). And this model is built into normal reaction force and friction force between rope and the pulley. By performing numerical simulation, the method that demonstrates the contact between rope and pulley was confirmed. Changing the differences of quantities which added to the both edges of the rope and the coefficient of friction between rope and pulley, it is certain that the behavior of the rope has changed.

In this study, we propose a new mobility device using tether (Tether Space Mobility Device, TSMD) for outer space. TSMD is the mobility device that moves user by taking-up the tether which is attached to the wall of the structure. This system has to contain the control system. So we applied two types of control system, arm control and taking-up control. Arm control reduces variation of posture by changing direction of tensile force autonomously. Taking-up control helps arm control by cause deflection and tension of tether deliberately. In this study, we designed the prototype of TSMD and produced it. The fundamental experiments of TSMD are performed by duplicated two-dimensional microgravity with the air bearing and the flight-table. From the result of experiment, it is found that proposed control system is effective. The effectiveness of control gain is also investigated.

Various vehicles are produced according to the development of the industrial technology. The driver will take a different driving posture for vehicles of these various vehicles. Moreover, not only the driving posture but also driver itself diversifies because of increases of the senior citizen and female drivers. The combinations of the driving posture and drives become vast number. In the future, the system that can simulate various driving posture and physical characteristic to develop the vehicle is necessary. Then, the study develops postural evaluation system based on biomechanics simulation. In this paper, the introduction of the outline of the postural evaluation system and the consideration of the posture evaluation result are done. From the results of numerical simulation, Muscle activity could be obtained according to running situation.