Some persons require assistance with their movements during meals. A support system for such persons would be invaluable. However, in designing such a system, crucial challenges such as freedom of movement arrangement and maneuverability of the system without disturbing human body movement have to be overcome. In this study, we extracted the major modes of human meal movement from meal movement motion-capture data and derived a suitable and feasible arrangement that reduces maneuverability variance in the workspace via iterative calculations based on inverse kinematics. The results of analyses indicate that the shoulder’s extension/flection and external/internal motions and the elbow’s extension/flection are suitable arrangements that give the freedom to equalize maneuverability in the workspace.

This paper describes a wearable encounter-type haptic device suitable for combined usage with a visual display. The features of the device lie in a driving mechanism that enables an encounter-type haptic display and the compact implementation of the entire device including the driving mechanism. The driving mechanism displays a natural haptic sense based on a smooth transition between follow-up and constraint of finger movements. The compactness is important because it contributes to preserving the quality of visual information when used together with a visual display. To test the basic performance of the device, the response of the driving mechanism was evaluated. The haptic display function was evaluated by a simulation in which the device is used to touch an object in a computer graphics (CG) space.

Practical ambulation must be realized by walking robots to enable social and industrial support by walking robots in human living environments. A four-legged robot that walks through rough terrain effectively does not erase the fact that most legged robots – particularly biped robots – have difficulty negotiating rough terrain. We focus below on a foot structure and landing control for enabling any type of legged robot to walk through rough terrain. When a walking robot lands on the ground, it is difficult to detect the detailed geometry and dynamic properties of the ground surface. The new foot structure we propose adapts to ground surfaces that have different geometries and hardness. The foot has four-part flat soles. The landing controller we apply to a robot with our proposed foot structure increases the stability of contact with the ground. We verify the effectiveness of our proposed foot structure in experiments.

Parallel-wire driven system, a kind of parallel-link mechanism, employs flexible and light wires in place of rigid links. By applying kinematics to parallel-wire driven systems, we seek to obtain the relationship between the end-effector’s position and wire length. Kinematics usually approximates the wire-contacting point of the winding reel (or guiding pulley) in the actuator unit to be a fixed point. Similar kinematic approximations, however, are likely to cause errors in controlling the end-effector position. In this study, therefore, we attempt to evaluate end-effector positioning errors due to inverse kinematic approximations. As the first step, we analyze end-effector positioning errors in two-degrees-of-freedom planar system and propose two methods to evaluate the positioning errors. Then, we conduct two case studies where we compare the errors due to inverse kinematic approximations and effects of wire’s elastic elements in order to confirm effectiveness of the proposed methods for evaluating end-effector positioning errors.

An extra degree of freedom to human body movement could assist people in a variety of tasks. To this end, we have previously proposed a human-ability extension system through a supernumerary limb. The system comprises of a manipulator that acts as a third arm, a feedback device that displays its status, and an interface that allows for its hands-free operation. Herein, we present this novel, intraoral interface that utilizes tongue motions and expiratory pressure. In contrast to the conventional intraoral interfaces that suffer from a lack of degrees of freedom and stability, our advanced interface is equipped with inertial measurement units and a pressure sensor to solve these problems without sacrificing the ease of use. The proposed interface is utile not only in our ongoing “Third Arm” project, but also in various other applications. We conclude with experimental evaluation of the system’s usability and its efficacy for human-ability extension systems.

In this study, we investigate the dynamic relationship between tension, contraction velocity, and length of the McKibben pneumatic actuators (MPAs) via experiments. Although MPAs are widely used in biomimetic robots or rehabilitation machinery, it has not been verified why they can exhibit stable motion from their simple structure. We analyze the relation of output tension, contraction velocity, and length. From the results of experiments, we conclude that the tension is related to both the velocity and the length of the actuator and the general form of this relation can be approximated as a plane. Moreover, we confirm that the parameters of the plane depend on the MPA pressure and valve condition.

The tracking control problem for the uncertain nonlinear feedback systems is considered in this paper by using passivity-based robust right coprime factorization method. Concerned with the passivity for the nonlinear feedback system, two stable controllers are designed such that the nonlinear feedback system is robust stable and the plant output asymptotically tracks to the reference output. A numerical example is given to show the validity of the control scheme as well as the tracking performance.

In this study, a novel robotic joint mechanism is developed for enabling a robotic joint to rotate around the axis by twisting a small-diameter round belt. This twist drive actuator mechanism is composed of two small-diameter round belts with opposite configurations located near the joint. The two round belts are twisted by using individual DC motors; thus, the joint is activated because of the contraction forces generated by the twisting process. Experimental results, obtained using the proposed single-link robot, demonstrate that the joint can be controlled with a high position resolution by increasing and decreasing the amount of twisting. Using the experiments, we reveal that the antagonistic twist drive actuator system has a secondary role in speed reduction, which is capable of decreasing the velocity of the joint movement significantly. In addition, we indicate a linear relationship between the twist rotation and the joint angle of the robot. Furthermore, this paper formulates the Young’s modulus of the round belt used in the twist drive actuator. We demonstrate that the Young’s modulus decreases gradually with respect to the increase in the twisting of the round belt. Finally, we demonstrate a successful position control of the robotic joint, and the traditional PI controller is capable of suppressing the oscillatory motion by using a one-sided twin-twisted configuration.

On-chip cell analysis is an important issue for microtechnology research, and microfluidic devices are frequently used in on-chip cell analysis systems. One approach to controlling the fluid flow in microfluidic devices for cell analysis is to use a suitable pumps. However, it is difficult to control the actual flow-rate in a microfluidic device because of the difficulty in placing flow-rate sensors in the device. In this study, we developed a real-time flow-rate control system that uses syringe pumps and high-speed vision to measure the actual fluid flow in microfluidic devices. The developed flow-rate control system was verified through experiments on microparticle velocity control and microparticle sorting.

This manuscript describes a scalable tabletop Manzai robot system that has been developed using distributed software components. Manzai is a style of traditional Japanese stand-up comedy that is typically performed by two comedians – a stooge and a straight man. Manzai script refers to the dialogues exchanged between the two comedians. Manzai robots automatically generate their Manzai scripts from web news articles based on keywords provided by audiences and search results on the Internet. Then, the robots perform according to these Manzai scripts. This study focuses on the flexibility and scalability of a robot system based on distributed Robot Technology (RT) components. The results of the implementation experiments demonstrate the flexibility of the Manzai performing robots and the scalability of the functions of the robot system.

This paper describes a road area detection method using a support vector machine (SVM) and histogram of oriented gradient (HOG) features. The boundary lines have many features, such as changes in height, color, and brightness, but these are sensitive to noise. In terms of robustness, it is difficult to match road boundary lines with the boundary lines on 2D maps. Localization methods using texture matching are accurate, but they have disadvantages related to adapting to changes in the environment. We therefore decided to make a classifier to differentiate road areas from other areas by detecting the road plane. First, we calculate the HOG features from range data acquired by 3D LiDAR. We then create the road area classifier by applying SVM. Finally, we evaluate the basic performance of the proposed method in simulation and in the real world.

In this work, we present a system to estimate the state of and control an Unmanned Air Vehicle (UAV) from a ground-based 3D laser scanner. The main contributions of this work are on data fusion between a low-frequency 3D laser scanner with considerable delay and an on-board 6-DOF IMU, and on automatic position control of a UAV using state estimate obtained from the fusion. We measured laser delay using data from a manually controlled flight. We have devised a method to perform online estimation and compensation of accelerometer offset using delay-corrected laser measurement. We then use the UAV state estimation in a nested controller with a high-frequency velocity control inner loop and a low-frequency position control outer loop. We demonstrated the state estimation and control in a series of experiments on velocity control and position control, including a comparison between position control using fusion data and only laser data.

The validity of navigation using an autonomous traveling algorithm based on loose localization (the lax localization algorithm) for an autonomous mobile robot with view sequences [1] was studied, and autonomous travel of the robot in a general town environment with people walking was experimentally demonstrated. The autonomous mobile robot was assumed to be a general cart-type robot with steering wheels and fixed wheels, which was able to make a translational motion in the traveling direction and a rotational motion around the midpoint between the fixed wheels (Fig. 1). The lax localization algorithm estimates only the distance in the traveling direction and the orientation of the cart, to make the robot follow the teaching path. The algorithm does not estimate the position in the transverse direction normal to the traveling direction. The cart orientation is estimated based on the direction in which a reference image can be viewed, and the position relative to the reference image in the robot traveling direction is estimated based the change in matching score. An autonomous travel experiment was conducted on the course of Tsukuba Challenge 2015 [a], and based on the estimation results, the robot could travel successfully in almost all the location of the course.

This paper presents a fault-tolerant approach for the propulsion systems of hexacopters (i.e., rotors and propellers) to overcome failures during outdoor autonomous flight missions. In this study, we used an explicit control allocation method for each stopped motor, and an asymmetrical motor rotation arrangement is applied in order to guarantee the controllability of the yaw. Finally, the developed fault diagnosis and isolation system is tested during a global-positioning-system-based autonomous flight of a hexacopter with a failed motor.

In recent years, a medical procedure called interventional radiology (IR) has been attracting considerable attention. Doctors can perform IR percutaneously while observing the fluoroscopic image of patients. Therefore, this surgical method is less invasive. In this surgery, computed tomography (CT) equipment is often used for precise fluoroscopy. However, doctors are exposed to strong radiation from the CT equipment. In order to overcome this problem, we have developed a remote-controlled surgical assistance robot called Zerobot. In animal puncture experiment, the operation of Zerobot was based on joint control. Therefore, during a surgery, the tip of the needle moves when a surgeon orders for a change in the direction of the needle. This makes the robot less user-friendly because the surgeon tracks the trajectory of the tip of the needle. This problem can be solved by using remote center control.

Concerning variable speed wind turbines, this study suggests a control scheme that combines integral sliding mode control (I-SMC) and fuzzy logic. The control task is to maintain the output power at the rated value for variable operating points. Wind turbines suffer from serious nonlinearities that challenge the control task. To attack the issue, the nonlinear turbine model is linearized at some typical operating points. Then, pitch-angle and generator-torque controllers based on the linearized turbine models are formulated by the I-SMC approach. Meanwhile, a fuzzy inference system is designed to weight those controllers. Not only the scheme can stabilize nonlinear wind turbines, but also the control system is robust to resist wind-speed variations. Some results are presented to show the performance of the control scheme.

The advanced aircraft has those technological characteristics: stealth, supersonic cruise, super maneuverability, multi-target attack, multi-role, high load, long range cruise, integrated avionics, short takeoffs and vertical landings. These characteristics need multi-subsystem integration in the advanced aircraft. In order to meet the need of advance aircraft, the nonlinear control system is necessary. In this paper, the nonlinear structure adaptive model inversion system was first used for the nonlinear control problem of super-maneuver aircraft. The sufficient and necessary condition of the control law was analyzed. Finally the results of the height-angle maneuver simulation show that the designed control system has good performance.

This study presents a fault-tolerance approach for hexacopters with failed propulsion systems (i.e., motors and propellers) using sliding mode control theory. In this study, we use an explicit control allocation method with linear constraints for allocating the control input to redundancy actuators, as well as a new sliding model controller designed to stabilize the attitude and maintain the basic flight performance of a vehicle with a single failed motor during an outdoor autonomous flight mission. An asymmetrical motor rotation arrangement is applied in order to ensure controllability for all degrees of freedom. We verify the developed system on a real hexacopter suffering propulsion-system failure. Finally, the comparative results between the linear-quadratic-integral controller and model reference sliding mode controller are presented to evaluate the robustness of each controller against the failure of redundancy actuators.

Workers in logistics sorting centers stand up by stretching their bent knees in order to pick up parcels. They use this method to prevent lower back pain. To assist these operations, an exoskeleton can support this motion of bending the knee joint. Therefore, to reduce the burden on the body during loading and unloading operations, we developed and performed the primary evaluation of power-assist technology consisting of a wearable exoskeleton that supports the knee joint motion.