In this study, we propose an estimation model of the lumbar load which is a factor of lumbar disorders. Proposed method uses musculoskeletal model that has elastic elements between the vertebral bodies, and simulates the intervertebral disk pressure and the displacement of the vertebral bodies simultaneously. This paper reports on the comparison with the experimental value of the displacement of the vertebral body in static conditions.

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The aim of this research is to develop a musculoskeletal robot arm which has a similar mechanical structure to that of a human. In recent years, many musculoskeletal robots have been intensively studied to investigate advantages of their mechanical designs. In this research, we focus on a shoulder complex, which consists of several bones and joints, because it is the most difficult part to develop in humanlike musculoskeletal robot arms. In particular, we develop a shoulder complex linkage mechanism that can realize complex 3DOFs motions of the scapula. The validity is confirmed in terms of its range-of-motion comparing with that of humans.

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In this paper, we developed a subject-specific musculoskeletal hand model considering the differences in the inertia properties and muscle force parameters. We measured motion and force data from one subject; the reference hand posture, three postures while the subject was pinching objects with 28, 42 and 56 mm width, and the maximum pinching force for each posture. By using a digital hand model made from motion data and force data for 42 and 56 mm objects, we assigned several properties and parameters in order to make this model subject-specific. We estimated the maximum force while the subject was pinching objects with 28 mm. As a result of the simulation, the maximum force was estimated to be 29.5 N that was almost agreed with the measured maximum force (26.5 N). These results suggest that it is possible to perform musculoskeletal simulation considering individual differences.

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This paper presents an articulated wheeled in-pipe inspection robot with holonomic rolling motion. The proposed articulated wheeled type robot can pass through elbow and branch pipes smoothly, and rotate around the pipe axis by using rollable hemispherical wheels. The robot can even twist like screw in the pipe by keeping the roll angle of the hemispherical wheels. To verify the basic behavior of this robot, preliminary experiments in an elbow pipe and a T-branch pipe were conducted. The experiments to verify the holonomic rolling motion and twist motion in a straight pipe were also performed.

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A novel locomotion mechanism called Actively Lugged Wheel mechanism (ALW) has been developed. An ALW prototype module is tested on typical terrains in this study. Climbing experiments on step, slope, and obstacle have verified the terrestrial mobility of the proposed ALW prototype.

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The functionality of a novel eccentric paddle mechanism (ePaddle) for amphibious robots has been validated on terrestrial terrains. To further test its underwater performance, the water-proof protection is realized by shielding its motors and developing a underwater absolute encoder. In this study, the design of the underwater absolute encoder is discussed and experimentally verified.

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Sandy terrain can be seen in various environments. For instance, beaches and deserts, and the surface of other planets are covered by sandy soil. In these types of environments, investigational robots are usually equipped with wheel driving mechanism having some protrusions called lugs or grousers. However, because the lug's motion trajectory and soil deformation interact each other intricately, there is no theory that support the relationships between generated forces and soil deformation or lug's moving trajectory. Therefore, in this study, we isolate the lug from the wheel and focus on a single lug. Based on experiments, the prediction models of generated forces are built and demonstrated the validity as a prediction equation.

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In this paper, a guide rail is designed to realize the stable climbing for a wall climbing robot with passive suction cups. Since the suction cups move relatively to the guide rail, their internal volume will be increased with the variation of the guide rail shape. Therefore, the increase of the internal volume of the suction cup leads to the decrease of the internal pressure, which improve the adsorption performance of the wall climbing robot. Experiments are conducted to confirm the usefulness of the guide rail and the climbing stability of the wall climbing robot.

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To enhance travelling performance on soft terrains, a novel wheeled mechanism named Active Lugged Wheel (ALW) for accessing sandy terrains has been proposed in our previous study. Based on this concept, a dust-proof ALW prototype towards field experiments is developed in this paper. The superior performance is verified by experimentally comparing the new wheel to conventional fixed lugged wheel. It has been found that the ALW generates larger drawbar pull and vertical force over a wider range.

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A novel cable reel named "Unicorn Reel" had been developed for mobile robots working in hostile environments. The Unicorn reel uses the Oscillating Level Winder Arm to lead the cable from the pipe to the winding system, which needs a constant cable tension to perform constant neatly winding. In this paper, we propose a control method to keep the cable tension constant for the Unicorn reel, which uses a leaf spring and a micro-displacement sensor. After the calibration of the leaf spring is performed, we also measure the cable tension by a force sensor and demonstrate the validity of the control method.

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Due to the unique and highly effective gaits used by snakes to traverse in unstructured environments, development of snake-inspired robot has garnered great interest in the bio-inspired robotics community. In this paper, we present a novel snake-like robot able to realize various gaits including three different patterns: undulation, rectilinear and rolling locomotion. Among these gaits, we specially describe the rolling locomotion that conventional robots and snakes in the nature do not possess. We report the design of wireless control system for four modules consisting three motors, which drive rotational, translational and rolling joints. Thus, the robot may be able to work through remote control, which promises that when robot realizes rolling motion, control cable won't enwind the body. We also achieve experiments to show that the robot is capable of turning around rapidly utilizing special rolling motion pattern on horizontal plane, and the snake robot is able to perform in complex environments utilizing composition gaits.

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This article shows a method for the derivation of a contact point for a passive suction cup with plate spring. First, the buckling shape of a plate spring is analyzed by the variational principle in statics. Next, the force balance of plate spring is calculated. Finally, the works of each contact point are compare. The reliability of the calculated results is then discussed through a comparison with the results obtained using simulations with the RecurDyn software package.

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The integrated robot design method designs a robot body and a robot motion simultaneously. In this method, not only the motion pattern, but also the robot body parameters are designed to maximize (or minimize) a given evaluation function which defines the robot motion performance. The proposed method also considers motion conditions which contain dynamical consistency, self-collision avoidance, limitations of joint angle, angular velocity and torque, etc.. These conditions are utilized as the constraints to obtain the feasible robot motion. In this paper, an integrated robot design method is validated by experiments of ball throwing motion. A ball throwing motion performed by a human is transformed to a motion pattern of the 9 degrees of freedom (DOFs) arm robot, and the robot body parameters are designed simultaneously. As a result, the robot motions are realized, and effectiveness of the integrated robot design method is demonstrated.

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This paper presents methods to ameliorate the hardware mechanism of the bipedal robot for the running experiment system based on high-speed visual feedback, called ACHIRES. In a new robot (Test Unit 2), we succeeded in enlarging the movable range of waist joints, enhancing the power of the actuators in each joint, and reducing the risk of cable interference around knees, which are keys to achieve more dynamic movements of the robot. As a first step of assessing the effect of above stated changes, we conducted the running experiment, in which we accomplished 4.2 km/h running and longer duration of air-staying time, leading to less risk of tumbling over. On the other hand, increased weight of the upper body brought new issue; larger pitch moment while jumping. In order to achieve further stable running, improvement of control method is needed which is capable of subduing the crucial moment while in the air and of calculating the optimum body angle at the moment of jumping.

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This paper proposes a novel concept called COG impedance matrix of a humanoid robot, which provides an explicit relationship with the joint impedance or joint PD controller. Using the COG impedance matrix, we can calculate the macroscopic feedback gain which approximates the joint impedance, and compute the maximal output admissible (MOA) set for falling detection. First-lag-order COP dynamics is also proposed to compensate the nonlinearity in the whole body dynamics.

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In the presence of humans, biped robots must avoid falling because falling down can lead to serious accidents. This paper presents a fall avoidance control method for biped robots under unknown disturbances that is based on real-time trajectory planning. First, a biped robot is modeled as an inverted pendulum. The robot generates in real time the trajectories of its center of mass and center of pressure, taking into account the dynamics and kinematics of the robot and the direction and magnitude of disturbances. By using the planning result, the robot returns to its stationary state after taking a few steps without falling. The experimental results show the effectiveness of the proposed method.

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Recently, a lot of researches for bipedal locomotion have been conducted. The high-speed running, which means that a Froude number is more than 1 so the robot can conduct only it, has not been achieved until now. In this research, we develop a humanoid robot that achieves the high-speed running, named rapid running robot (R3). The development and control of this robot need an accurate model to analyze the robot's locomotion. We then model R^3 after a real robot, which has already achieved the running, in a dynamic simulator V-REP.

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This paper presents the method to retarget human motion, which can evaluate the ability of the preservation of the original characteristics of human motion data. It enables to compute the joint trajectories of the human corresponding with the retargeted ones of the robot at the same time, by utilizing the geometric identification techniques for human motion capturing. The proposed method are efficient for such applications that the robot need to mimic human motion without modifying the detailed features of the original movement of each body segment. The results of the retargeted motions to a humanoid robot are to be shown.

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In order to decrease landing shock on axial-driven jumping humanoids by electronic control instead of hardware elasticity, it is necessary to improve the response speed of the inner control systems. We have developed a Node-to-Node distributed control system for the high-power humanoids by connecting the high-power motor drivers with the real-time distributed communication link, "Responsive Link". In addition, we developed a shock detecting system with accelerometers instead of force sensors necessarily installed via rubber bushes. We proved that the proposed systems are effective improving the response speed of high-power humanoids against input shock, and we realized the reflex action with the proposed systems.

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In this paper, we propose a method to search possible trajectory that maintains the balance of an actual humanoid robot, by using pressure distribution obtained from the sensor. First, data acquisition is performed to gather sample for observation. After then, estimated Jacobian matrix from collect data, is used to perform trajectory search considering the balance. To verify our method, experiments were conducted by installing the robot on a sheet type pressure sensor.

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Passive dynamic autonomous control (PDAC) for bipedal walking has excellent efficiency. PDAC, however, can control walking direction only in the previous research, and not be used for 3-D walking currently. We then propose a 3-D walking method of PDAC by using a walking speed controller based on a swing-leg motion. The reference walking speed to reach the goal is achieved by adjusting the touchdown position and speed of the swing leg. As a result, the 3-D walking is achieved with the high energy efficiency, although the footstep is hardly controllable.

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This paper describes the development of a one-legged jumping robot that can mimic the muscular and skeletal system of a human leg. A balance system that is developed in this study is installed on the waist to control the orientation of the robot. The robot has a hip, a knee and an ankle. The effectiveness of the mechanism of the robot are verified through attitude and jumping experiments.

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In order to use humanoid robots as a substitute for the human, we have to be able to generate any kinds of humanoid robots' motion. However generating motion for humanoid robots is complicated because we have to generate as many input variables as the number of their joints. Thus in many cases, human motion data is used to generate humanoid robots' motion. However, since capturing all kinds of human motion is not practical, we need to generate various motions by interpolating finite number of motion data. In addition, typically generated motion has to fulfill some kinds of constraint conditions with end effectors. In this paper we use smoothing added constraint conditions as a penalty and Functional PCA to implement motion blending which enables to generate intermediate motion of some motion data.

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A 5-DOF anthropomorphic shoulder mechanism is presented. A combination of two four-bar links mimics elevation-depression and horizontal abduction-adduction motions of a scapular-clavicle in addition to a spherical rotation of the root of the upperarm. It provides a humanlike movement and contributes to enlarge the workspace of the arm without reducing the support rigidity. The mechanism was analyzed with a help of the compliance ellipsoid.

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In order to enable a humanoid robot to drive vehicles, it is important for the robot to recognize environment autonomously to a certaing degree. It is also significant that a humanoid robot can correct its body tilt in accordance with its postural change. In this paper, we propose the way for a humanoid robot to determine how much to turn a steering wheel by environment perception and practical local path planner for driving vehicles. Force control method is also presented in order to correct its body tilt when a humanoid robot drives vehicles. Effectiveness of these methods is confirmed in an experiment in which a humanoid robot drives Polaris vehicle along complicated road with six corners.

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A communication between a human and a robot is an important issue when they live in the same space. If a communication is smoothly performed between them, robot working fields will be greatly expanded in a human living space. In this paper, a humanoid robot aiming to realize a smooth communication with a human was proposed. The robot consists of an upper body with the same D.O.F as to that of a human and a wheeled inverted pendulum type mobile platform. The upper body has 22 D.O.F including 2 D.O.F scapula joint in its manipulator. A mechanism and a control system was described in this paper.

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Humanoid robots with a large number of compliant joints with wide ranges of motion is durable, because they can avoid postures that may destroy their surroundings and their own bodies. However, it is difficult to equip robots with such joints similar to humans due to space limitation. For this problem, a child type robot " Affetto " has been developed and a large number of compliant joints has been realized in its small body by using both rotary and linear pneumatic cylinders. However, particularly in its shoulder, ranges of motion is not sufficient to show several human-like postures. In this paper, we aim at the development of compact shoulder mechanism having five degree of freedom and wide range of motion by using air cylinders.

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Recently, robots are expected to work in real environment to support our daily lives. However, there are a lot of disturbances in such a environment. A robot with many degrees of freedom might be beneficial in coping with various disturbances in a real environment, because it can generate many kinds of motion. However, because of its complicated structure, it is difficult to estimate its dynamics which is necessary to design the control rule. In this paper, we discuss about 3 data-driven methods (k-nearest neighbor, support vector regression and Gaussian process regression) for estimation of a human-like upper body musuculoskeletal robot driven by air actuators.

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We present the mechanical design of our new hydraulic humanoid robot RL-H2. Compare to our previous model, the robot is installed with the upper half of the body and arms. The joint specification is determined by dynamic full-body simulations including the falling motion. To make the robot have the same mass distribution as the human, the main parts of the robot is made out of CFRP plate. This paper describes the design process, simulation results, and mechanical specifications.

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Visual-feecback balance experiments on compliant life-sized humanoid robot is conducted. A 120 fps camera is mounted on a base frame of the robot, and visual feature points are given by LED arrays on a vertical plane in front of the robot, and the positon and orientation of the base are estimated at every 10 ms. The experimental results show that the robot can dynamically keep its balance while pushed from the side, and the vision performs almost equally as the forward kinematics using IMU and joint position sensors in this simple experimental setup.

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This paper presents a one-sheet type biped soft robot using shape memory alloys(SMAs) for not to damage cultural assets. A sheet structure is assembled from one polyethylene plate only. The paper shows a SMA actuators consisting of a thin polyethylene plate and biped soft robot like paper folding, or "Origami". In this study, we attempted to improve the mechanisms for walking by the improvement of nails and stopper.

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Optimal feedforward trajectories of a carriage are derived in an overhead hoist transfer machine for quick suppression of residual oscillation in a hoisting load by using vibration manipulation function. By deciding the route of the load as that of linear rotational oscillation, proper carriage trajectory can be determined under the influence of nonlinearity and the elevation/descendent of the load. Since intermittent acceleration function can decide discrete positions and velocities of the load, trajectory of the carriage realizes quick suppression of residual vibration under non-approximated situation. To confirm the method, some results of simulations and simple experiments will be shown.

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For social advancement of robots, robots using deformable objects as tool similar to the rigid tools are important. In a prior research, robots used deformable tool by iterative learning. And another research, robots manipulate a string using a complex deformable object model. However, it is important to succeed in one time trial and decreasing calculation and measurement cost by simplifying models for adaptive action. Here, we propose a new method that robots measure a natural period of deformable object, estimate stiffness of simplified model and generate motion to perform retrieval tasks adaptively. As a result, we showed validity of the proposed method in various stiffness of model and efficacy with non-uniform model in simulation. Moreover, we constructed a real robot performing retrieval task with real deformable objects. By our research, we expect that robots advance into human society more and more.

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This paper proposes an inflatable robotic arm controlled by a joystick for welfare robots. The robot arm is constructed of inflatable links, pneumatic bag actuators, and ABS joints. The robot arm has softness and lightness in comparison with general robotic arms which made of metal and heavy elements. The softness and lightness realize intrinsic safety. Therefore, the robot is expected to apply for the welfare robots. In this paper, we propose a new control method for joystick operation. The method is robust to errors of physical parameters of the robot. Thereby, the method is suitable for the inflatable robot arm whose links are easily deformed. Some experiments using the robot arm is demonstrated to confirm the usefulness of the proposed method.

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We developed an antagonistic variable elastic mechanism (AVEM) which can control the elasticity and the equilibrium position of the joint. However, the elasticity and the equilibrium position of the AVEM change depending on the joint angle. Therefore, it was difficult to precisely make the elasticity and the equilibrium position. To overcome this difficulty, we propose a new AVEM in this paper. The elasticity and equilibrium position of the proposed mechanism do not depend on the joint angle. Moreover, we propose a new control method in which motions are generated by adjusting the equilibrium position. The performances of the proposed mechanism and the control method are demonstrated by some experimental results.

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Many robots and machines advance into our society recently, and the necessity of making sure of improving safety is more and more increasing. We develop a new shape-changing robotic exterior. This robotic exterior is made of air bladders, and able to change its shape via inflation and deflation. It is soft, light, economical, and not disturbing primarily behavior of an objective which wear this robotic exterior. And we apply it to a real robot and do some experiments in order to evaluate performance of it. Consequently, we show that this robotic exterior has many functions such as shock mitigation and improvement of grasping behavior.

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This paper discusses a dynamic nonprehensile manipulation by using a vibrating plate. The omnidirectional manipulation for an object on the plate surface by a single active joint, is proposed. For the plate vibration mechanism, we introduce the nonparallel type active-passive hybrid joint with viscoelasticity. We show that the omnidirectional manipulation can be achieved by controlling three input parameters of the active joint: the frequency, the amplitude, and the offset angle. After showing the relationship between three control parameters and the object's translational velocity, we further discuss the optimum design parameters, including the viscoelasticity of the passive joint. Finally, we show experimental result by using the prototype robot, for confirming the validity of the proposed method.

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Tactile walking surface indicators (TWSIs) are necessary devices for independent walk of visually impaired person. However, if these blocks installed following guidelines for constructing TWSIs, it's unkindness to users. Therefore, we propose LED blocks installed at crosswalk entrance for blind and visually impaired persons. These blocks can be detected through the soles of shoes and through use of residual vision. This study is conducted experiment that invited amblyopic examinees. In this study, we evaluate the visibility of the LED blocks.

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The main purpose of this project-based study is to develop robot with human- and eco-friendly smart materials. The project was executed by several researchers whose special fields are not necessarily limited to robotics and mechatronics. In this paper, the impact reduction robot system is mainly developed, and the related technologies such as green composite materials, noise and vibration analysis method, and so on. Moreover, the resultant outcome is introduced via social researches and the exhibition held in Tokyo International Exhibition center.

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This paper provides a miniature flexible robot hand in consideration of the universal design. Our flexible robot hand is composed of a palm and three fingers. Each finger has one degree of freedom of motion and the arrangement of fingers can be changed. We conducted the experiment for the ability of grasping in order to clarify the effectiveness of our robot hand system.

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In the near future, it is expected that people using wearable power assist device will increase. As a result, appearance of the product of various variations will be expected. These products need to ensure sufficient safety. In this study, we consider a mechanism that can ensure safety in hardware. The mechanism can be transferred joint stiffness of robot mechanically. So far, we developed the joint stiffness adjustment mechanism using a non-linear spring SAT. In this study, fundamentally review the joint stiffness adjustment mechanism using a SAT. We propose a flexible joint mechanism joint stiffness is transferred to the three modes. The single joint experimental apparatus using the three modes SAT for rotating joints are actually designed and manufactured. It was verified the operation principle by actual experiment. From actual experiments, the characteristics of the three modes SAT is confirmed to be transferred to three stages in accordance with the rotation angle of the rotating joint. Eventually, this study aims to develop wearable power assist device with low output and using a spring element for the purpose of compensation of physical ability of people.

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In this study, an exoskeletal biped robot which consists of flexible members is proposed. The mass and height of the robot are 0.9 kg and 320 mm. The exoskeletal flexible robot walks using static walking techniques. We evaluate the walk through the step length and speed of the robot. We also investigate the impact resistance of the robot through several experiments. Prom results of drop experiments to the robot by weights, the robot is not broken out up to 8.2 J of potential energy. From results of drop experiments of the robot to floor, the robot is not broken out up to 850 mm height.

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In order to copy beautiful motions from human dancers, it is important for robots to have the flexible spine structure. In this paper, we describe the method to build an elastic spine structure from a single carbon rod. This spine structure has 3 characteristics, (1) the seamless S-curve, (2) simple composition and (3) light weight. We added 9 motor actuator modules to this structure and developed a ultrahigh-DOF wire-driven carbon rod spine robot to test our design principle.

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In this paper, we propose a position and orientation measurement system based on shape estimation of elastic rod. The proposed system consists of an elastic rod, a 6-axes force/torque sensor and a PC with a display for real time measurement and display. The tip end of the elastic rod is attached to an object to be measured while its base end is fixed to the ground through the force/torque sensor. The system calculates the position and orientation of the object in real-time through estimating the shape of the elastic rod from the force and torque information. The shape estimation can be achieved by a simple recursive computation from force/torque information at the base end, based on a discretized model which approximates a continuum elastic rod with a serial-chain of rigid bodies connected with passive elastic joints. We show a numerical example to verify the effectiveness of the proposed calculation method.

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This paper discusses the evaluation method for a flexible tail which has a function to memorize its spatial shape. If the flexible tail is memorized its shape during swing, the flexible tail give larger inertial force to a robot body than a rigid link tail. In order to evaluate the developed tail with variable stiffness mechanisms which uses the friction between particles, the evaluation method about the time until memorize its shape is discussed in this paper.

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This paper describes object transportation with sheet type soft robot with a magnetic fluid. We propose this robot with indication that the robot can transport a sphere on its surface deformation. However, to obtain practical use with this robot we must consider the method in which the robot transports several objects and a non-rotating object. Therefore, we verify the ransportation ability of this robot by making the robot move two spheres and a thin circular plate on its surface. By exploiting the surface deformation, the robot can transport these objects.

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This paper proposes a flexible motion control based wave theory. In robotic applications, vibrations due to mechanical resonances often occur because of use of some flexible mechanism or reduction of mass. Additionally, the rapid motion which have been possible to be realized by development of the motion control theory induces the mechanical resonances. Therefore, it is important to consider the vibration suppression of resonant systems for achieving the precise motion control on robotic systems. In this paper, the resonant system is modeled as a wave equation to consider high-order vibrations. Based on the wave model, the reflected wave rejection to suppress the vibration with considering the bandwidth of a disturbance observer is proposed. The validity of the proposed method is verified by the numerical simulations.

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A dementia which one of the higher brain dysfunction is reduces quality of life. To protect this, outside support can advance conation of dementia patients and self-efficacy. On the other hand, remote operation of robot can keep interest of dementia patients. But, it is impossible to advance self-efficacy because this isn't an active participation. To advance self-efficacy of dementia patients, we germinated the robot race game, and developed robot operate system which dementia patients can operate with themselves physical exercise. To advance self-efficacy of dementia patients was recommended because they laughed for operating robot in this study.

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We have developed an evaluation environment of the control device of a robot arm by computer simulation to realize the smart control device for the robot. Thus, a displacement input device, a joystick, a keypad, and a tactile sensor were evaluated according to the difference in size and operation method. For the simple pick and place task of the simulation, a keypad was the best performance. However, the evaluation task and control method of each device are to be improved. We describe the developed simulation system and the evaluation result.

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This paper describes the face tracking control for the facial recognition using optical zoom camera. It is a purpose that the system can recognize a face regardless of distance by using a zoom camera. When zooming in, the face of the target is to go out from an angle of view, but it is the characteristic of the system to control a pan-tilt mount so that the face is projected in the center of the image by using facial recognition library, Neoface. We have confirmed the effectiveness of this method by experiment, but a tracking target must walk slowly. The improvement of the system became the future work.

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