There is a serious caregiver shortage in Japan as a result of the country’s aging population and the corresponding rise in nursing care demand. Therefore, the most basic human activity, standing up, needs a robot that can teach the disabled person to stand up while relieving the burden on caregivers. In recent years, standing support robots have been developed for practical use to reduce the burden of caregivers and to support rehabilitation toward independence. However, there are issues such as the lack of motor learning for persons requiring nursing care that enables them to reacquire standing movements due to their center of gravity and posture that differ from normal standing movements, and the inability to apply the robot to persons requiring nursing care who have difficulty with standing movements. In this study, we developed a standing support robot that supports lifting of the trunk, which reduce a large burden of caregiving. Meanwhile enabling motor learning for those who require care. Specifically, the robot supports only the guidance of postural changes in the lower limbs without lifting the care receiver, thus the care receiver’s weight is supported by himself/herself. Finally, we verified the load on the care receiver plantar foot in an experiment in which an able-bodied person simulated assisting a care receiver in standing up motion and confirmed that the caregiver’s workload was reduced, which demonstrated the effectiveness of our proposal.

When cleaning the dirt pile around the conveyor with a vacuum car, there are problems that workers collide with falling iron ore and suffer health problems by breathing in dust. Therefore, it is necessary to develop a robot that performs the cleaning with a vacuum car instead of workers. Many studies on robots that perform cleaning work have discussed about automation and cleaning efficiency such as automatic mapping and coverage path planning. However, there is no discussion about cleaning efficiency and automation of robots that can perform the cleaning with a vacuum car. To perform the cleaning efficiently, it is necessary to avoid cleaning the same place several times and leaving uncleaned areas because it increases the cleaning time. Therefore, in this study, we first formulated the area where the hose sucks the dirt pile. Then, we proposed a method to derive the optimal path that minimizes the cleaning time. Furthermore, we developed a control system that realizes the optimal path. Finally, we conducted a verification experiment assuming an aisle next to the conveyor. In the experiment, it was confirmed that the coincidence rate with the optimal path was about 70% by the suction-port position control system.

Nowadays, it has been actively expanded to develop assist robots attached directly. In this study, we focused on developing an exoskeletal robot, specifically, a force transmission robot with a rotary drive type ratchet mechanism, to enable users with upper limb disability to make use of their residual function to achieve better function of their upper limbs. A lock/unlock mechanism on the elbow joint is effectively used to transmit the user’s residual function around the shoulder to the hand. We conducted verification experiments on whether the developed mechanism enables the user to transfer the remaining force in the shoulder joint to operation force in the hand. Three subjects with C5 and C6 spinal cord injury with disabilities affecting their hands, lower limbs, and trunk muscles performed the verification experiment with the developed device. We confirmed that they could operate a wheelchair on a slope and on grass when using the developed device, and they could use their residual function around the shoulder more strongly. It can be expected to rehabilitation effect.

Vehicle performance tests are conducted to evaluate factors of vehicle performance such as fuel consumption and durability. Robotic drivers are often used in these tests to ensure that performance evaluate is reproducible, and various types of vehicles have been tested. Manual transmission (MT) vehicles are widely used and represent about 50% of vehicles in the world. When the driver selects the gear ratio in MT, speed control performance is degraded during changing the gear. Because a torque transmission between the engine and wheels is cut during this sequence, the driver must drive the vehicle while considering the influence of changing the gear. Therefore, control performance in MTs depends on driver's technique. If robotic drivers are used with MT, there is a possibility that performance will be significantly degraded because the robot cannot adjust to change the gear while driving. In this paper, we realized the driving while considering shift changes by the robotic driver. First, we modeled the lack of a driving force using the dynamic characteristics of the vehicle and the deceleration during changing the gear. We then derived a target vehicle speed waveform using the lack of a driving force model. Finally, we performed vehicle tests using a robotic driver. We confirmed the effectiveness of the proposed system from the results of actual vehicle tests.

In vehicle performance tests, fuel consumption, the components of exhaust gas, and mileage are measured on a chassis dynamometer that simulates the road load. It is difficult even for a professional driver to maintain speeds within the tolerance band of driving test cycles. Thus, there has long been an expectation that robotic drivers will be able to test vehicle performance with high reproducibility. In previous studies of robotic drivers, the improvement of tracking performance has been studied for each driving test cycle. In this study, we proposed a control system for realizing a driving test with smooth pedal use and low fuel consumption. We derived a set reference speed profile within a tolerance band from a driving test cycle standard. First, we performed a vehicle pre-test with a professional driver. From this driving test, we found that the square value of the power consumed by the vehicle was effective for driving with smooth pedal operation. Therefore, we proposed an objective function considering the square value of the power. We then derived the reference speed in a driving test cycle tolerance band for the robotic driver by the proposed method. Finally, we performed the vehicle test using the robotic driver. In the test, we used a standard JC08 chassis dynamometer, a moving averaged JC08 waveform, and the proposed speed waveform. We made sure that the proposed system was effective using the results of the actual vehicle tests.

We previously proposed a motion support robot and conducted experiments in which a C5-level cervical cord injury patient used the system. This paper proposes to offer motion support to a C4-level spinal cord injury patient who suffers from paralysis of the limbs. Electromyogram (EMG) signals are used to determine the user's intentions. The proposed motion assist robot can then support flexion and extension at the elbow joint. Using frequency analysis of the EMG signal, the patient's intention can be estimated in real time, and the coefficient of viscosity is varied in an admittance controller. With the proposed motion assist method, we were able to realize arbitrary upper limb motion of a C4-level cervical cord injury patient.

Thousands of individuals of all ages are living with a spinal cord injury as a consequence of a traffic, or sports accident or other calamity, and many of these individuals incurred a C5-level spinal cord injury, with a loss of the ability to use their legs and exert extension force from the elbow joints. Many of the motions that are necessary in daily life are difficult or impossible to perform with this level of spinal cord injury, and it is expected that wearable motion-assist robots will someday be available for use by individuals with C5 injuries. In order to be wearable, an assist robot must not limit the user's range of motion while being used, and it must be suitable for a wide range of situations. In the present study, we developed an extension force support system that acts in accord with the operator's intentions under the effect of external force as the operator use a wearable motion-assist robot for an upper limb. The effectiveness of the developed system was demonstrated experimentally.

Creative activities, such as painting and music, are one source of satisfaction and fulfillment for people with disabilities. However, some individuals with a disability can not satisfactorily enjoy such activities because of involuntary movement or spasms. In this study, we developed a drawing assist system for patients with cerebral palsy of the tension athetosis type, who experience spasticity that makes it difficult for the assist system to distinguish involuntary movement from voluntary movement. We designed a variable filter to attenuate involuntary movement on the basis of the behavioral characteristics of the velocity component with respect to in voluntary movement. Our system enabled drawing based on the participant's own senses and motor control, even when experiencing involuntary movement.

Many people of all ages have sustained cervical cord injury in traffic accidents or sport accidents, and con sequently suffered physical impairment. For individuals with paralysis of the lower limb who have also lost the ability to extend the elbow, many motions become difficult to perform in daily life, for example, independently operating a wheelchair or pushing open doors. In the future, wearable assist robots are expected to be incorporated into daily life. In order to be wearable, the assist robot must not limit the user's range of motion while being carried or used, and must be suitable for a wide range of situations. In this study, we developed an assist robot for upper limb movement which can assist wheelchair operation. To achieve this, we constructed a model of the upper limb during wheelchair operation with a manipulating force ellipsoid, and we developed an assistance control method for the upper limb using the device to apply force vectors. The effectiveness of the developed system is demonstrated experimentally.

Many people of all ages have sustained cervical cord injury in traffic accidents, falls, or sport accidents, which has resulted in their physical impairment. Among such individuals, dysfunction of the upper limb is of particular concern, even though recovery from dysfunction is possible through rehabilitation. In this study, we developed a wearable assistive robot for the upper limb; this robot can be used to perform various tasks involving upper limb motion in daily life. To achieve this, we devised an algorithm for assisting extension motion. Individuals with C5-level Cervical Cord Injury (CCI) cannot perform extension of the elbow on their own. Therefore, we calculated the reference velocity curve and the angle of extension only from the force in the direction of flexion. In this way, the wearer can autonomously adjust the movement.

In the near future, there will be a significant problem obtaining workers in the fields of welfare and nursing care because of a labor shortage. To solve this problem, many welfare robots, such as an upper extremity motion assistance robot and a meal assistance robot, have been studied. The purpose of this paper is to avoid spilling of the liquid when the spoon is transferred. In order to avoid spilling of the liquid, a spilling model was evaluated by using a CFD simulator. Thus, it was not necessary to build an exact model of the spilling model mechanism. The effectiveness of the proposed control is shown by CFD simulations and experiments.

This paper presents a new redundancy resolution approach based on the gradient projection method, which allows to avoid man-machine and machine-machine collisions as well as singularities of a redundant haptic interface. On this account cost functions for singularity and collision avoidance are formulated. Hereby the collision avoidance cost function is derived from a kinematic analysis of the human arm. Appropriate weighting factors are used to guarantee a simultaneous optimization of all defined side criteria. The performance of the presented method is analyzed by simulation.

In the near future, a labor shortage will constitute a significant problem in the fields of welfare and nursing care. To solve this problem, researches are working to develop welfare robots such as an upper extremity motion assistance robot. Our goal is to develop a meal assistance robot that can help a disabled person. Meal environment information is transmitted to an operator by haptic control. For better operational feeling, variable impedance control using the potential method is applied. The potential field was derived by a diffusion equation to construct an algorithm of velocity restriction for haptic feedback.

In this work, we present novel VR training strategies that incorporate a hybrid trainer model to train force. For modeling the trainer skill, weighted K-means algorithm in parameter space with LS optimization is implemented. The efficiency of the training strategies is verified via user tests in frame of a bone drilling training application. An objective evaluation method based on n dimensional Euclidean distances is introduced to assess user tests results. It is shown that the proposed strategies improve the student skill and accelerate force learning.

The purpose of this paper is to explore the development of a semi-automatic obstacle avoidance control system that combines manual instructions from an operator with the automatic control of a machine. First, in order to obtain operational support, we employed a special joystick system which provided suggestive information to a crane operator via haptic feedback. The information imparted included such factors as the application of impedance control, gravity compensation, and restriction on the crane's velocity. Second, an integrated system comprised of a restriction system for rotational angle and boom-luffing angle, as well as an obstacle avoidance system was built. Finally, the effectiveness of the proposed obstacle avoidance control system using haptic control was validated through experiments, testing whether or not the present system could transfer a load easily and safely to any target position without colliding with obstacle.

In this work a virtual reality medical training system (MTS) for bone drilling skill training is presented. For this purpose a novel controller algorithm, two graphical user interfaces for teaching and simulating purposes are developed. A 3 DOF haptic display that is developed in our laboratory is used for force feedback. Several user tests are performed to validate how the developed MTS helps for skill improvement. The effects of adding acoustic feedback and the advantages of using a 3 DOF haptic display instead of 1 DOF are investigated. Preliminary user studies suggest that the proposed system can be a powerful tool for teaching how to drill into bone.

This paper introduces a system of advanced control of the automatic pouring process, including the control of liquid level in the sprue cup, the flow control as the liquid is poured into a mold and sloshing (liquid vibration) suppression in the ladle. Through the pouring process model built in this paper, we calculated a forward tilting control input to hold the liquid in the sprue cup at a constant level. A backward tilting input is obtained by means of the Hybrid Shape Approach applied to suppress the slosh after backward tilting. We also designed a model by which supervisory control can take into account the After-Flow that occurs when switching the forward tilting input to the backward tilting input, and thus achieve the accurate poured quantity. The validity of the proposed total control system was demonstrated through experiments.