Daisuke Chugo

Force assistance system for standing‐up motion

In our current research, we are developing a force assistance system for standing up motion. Our developing system realizes the standing up motion using the support bar with two degrees of freedom and the bed system which can move up and down. In this paper, we develop the force assistance system which realizes the natural standing up motion using remaining strength of the patient. Our key ideas are two topics. The first topic is distributed system which controls the support bar and the bed system with coordination among them. The second topic is the combination of force and position control. According to the patients posture during standing up, our control system selects more appropriate control method from them. We use the reference of standing-up motion which is based on the typical standing up motion by nursing specialist for realizing the natural assistance. The performance of our proposed control scheme is experimented by computer simulations

A rehabilitation walker with standing and walking assistance

This paper proposes a robotic walker system with standing and walking assistance function. Our system focuses on domestic use for aged person who needs nursing in their daily life. Our key ideas are two topics. The first topic is combination of standing assistance function and walking assistance function. In previous works, many assistance devices are specialized in only ldquostanding-up operationrdquo or ldquowalking operationrdquo. However, in their daily life, elderly person needs standing, walking and seating assistance continuously by a same device. Our developing assistance system can support both operations by a small sized mechanism with low cost for domestic use. The second topic is steady standing assistance operation using an assistance manipulator and an active walker. In order to use the remaining physical strength of the patient, it is required to maintain the patientpsilas body posture which enables him to use own strength easily. According to the patientpsilas posture during standing up, our proposed system selects more appropriate device and controller, and realizes the standing assistance with steady posture of the patient based on the nursing specialists. The performance of our proposed system is verified by experiments using our prototype.

Development of a control system for an omni-directional vehicle with step-climbing ability

This paper proposes a control method for wheels to pass over rough terrain. In our previous work, we have developed a holonomic mobile mechanism capable of running over steps. The mechanism realizes omni-directional motion on a flat floor and passes over uneven ground in forward and backward directions. The vehicle has seven special wheels with cylindrical free rollers and two passive body axes that can adapt to rough terrain. Seven actuators are located in each wheel; therefore, our vehicle system requires the rotation velocity of each wheel to be coordinated. However, it is difficult to keep such coordination among the wheels — as the vehicle passes over the step, the load applied to the wheel tends to heavy and irregular. Therefore, we propose a new control system for synchronization among the wheels. In this paper, the following two topics are discussed: the load adjustment so as not to exceed the maximum torque of the actuator in some of the wheels and keeping the balance of rotation velocity among the wheels. Our novel control method adjusts the output value by referring to the state of the other wheels. The performance of our system is investigated by means of computer simulations and experiments using our prototype vehicle.

Force Assistance Control for Standing-Up Motion

In our current research, we are developing a power assistance system for standing up motion. Our developing system realizes the standing up motion using the support bar with two degrees of freedom and the bed system which can move up and down. In this paper, we develop the control scheme which realizes the natural standing up motion with fewer loads to the patient. For developing control scheme, we investigate the standing-up motion of aged people who requires to power support and typical standing up motion by nursing specialist. Comparing with two motions, we set the reference of standing-up motion with our system and we discuss the required assistance force during standing up. Our key ideas are two topics. One topic is control reference using zero moment point. Zero moment point is useful index which shows stability of the patients posture. The other topic is combination of force and position control. According to the patients posture during standing up, our control system select more appropriate control method from them. The performance of our proposed control scheme is experimented by computer simulations

Rehabilitation Walker System with Standing Assistance Device

This paper proposes a walker system with power assistance device for standing up motion. Our system focuses on family use for aged person who needs nursing in their daily life. Our key ideas are two topics. The first topic is new assistance manipulator mechanism with four parallel linkages. Our proposed manipulator mechanism requires only smaller actuators and realizes rigid structure with lighter linkages comparing with general manipulator. Thus, we can design our assistance system compactly with low-cost using our mechanism. The second topic is the combination of force and position control. According to the patients posture during standing up, our control system selects more appropriate control method from them. We use the reference of standing-up motion which is based on the typical standing up motion by nursing specialist for realizing the natural assistance. The performance of our proposed assistance system is verified by computer simulations using the model based on our prototype.

Force Assistance System for Standing-Up Motion

In our current research, we are developing a force assistance system for standing up motion. Our developing system realizes the standing up motion using the support bar with two degrees of freedom and the bed system which can move up and down. In this paper, we develop the force assistance system which realizes the natural standing up motion using remaining strength of the patient. Our key ideas are two topics. The first topic is distributed system which controls the support bar and the bed system with coordination among them. The second topic is the combination of force and position control. According to the patients posture during standing up, our control system selects more appropriate control method from them. We use the reference of standing-up motion which is based on the typical standing up motion by nursing specialist for realizing the natural assistance. The performance of our proposed control scheme is experimented by computer simulations.

The Analysis of Excavator Operation by Skillful Operator

In recent years, some unmanned operation systems for the hydraulic excavator are required and some systems are already developed. However, it is difficult to realize effective operation utilizing such systems, because the operator cannot sense ground condition. The skillful operator adaptive their operation to the excavating environment based on the experience, and realizing the efficient excavating. In this paper, we described the experiment for extracting operators skill for controlling unmanned hydraulic excavator. We compare the operation of skillful with non-skillful operator and discuss the result for the modeling of operators skill. From these results, we have revealed that skillful operator realizes unified trajectories of the bucket with quick moving and this causes the efficient performance.

The analysis of excavator operation by skillful operator - extraction of common skills -

In general, the hydraulic excavator is used on many construction sites, but in many cases, these construction sites are bad environmental conditions. Therefore, the unmanned excavator system is required. In recent years, the teleoperation systems have been developed and some of them are in practical use. In these systems, the operator cannot sense condition of site directly, so the work efficiency decreases comparing to a direct control by human operator. On the other hands, there is an approach to realize the unmanned excavator operation based on the autonomous machine control system. However, it is difficult to make its model and plan the excavating trajectories because it is difficult to make an excavating environmental modeling. Besides, it is thought that the skillful operator adaptive their operation to the excavating environment based on their empirical knowledge, and realizing the efficient excavating. In this study, we are developing an autonomous excavator control system with efficient operation function based on analyzed skills of operation by the skillful operator.

A robotic walker with standing assistance

This paper proposes a walker system with power assistance device for standing up motion. Our system focuses on family use for aged person who needs nursing in their daily life. Our key ideas are two topics. The first topic is new assistance manipulator mechanism with four parallel linkages. Our proposed manipulator mechanism requires only smaller actuators and realizes rigid structure with lighter linkages comparing with general manipulator. Thus, we can design our assistance system compactly with low-cost using our mechanism. The second topic is the combination of force and position control. According to the patientpsilas posture during standing up, our control system selects more appropriate control method from them. We use the reference of standing-up motion which is based on the typical standing up motion by nursing specialist for realizing the natural assistance. The performance of our proposed assistance system is verified by computer simulations and experiments using our prototype.

Improvement of assistive wheelchair caster unit for step climbing

The objective of this study is to develop the mechanism which assists the wheelchair user to climb a step. The wheelchair caster unit with an assistive mechanism is developed. This unit is easily replaced with the conventional wheelchair caster. The proposed caster unit has two functions to assist the step climbing. One is the assistive plates to enlarge the caster radius imaginarily. The other is a lock-function to yaw axis caster rotation, which realize easy climbing with oblique approach. Our first prototype shows good performance for above mentioned two functions, and can assists step climbing. However, the first prototype is heavy, because of the electromagnetic tooth clutch is used for the lock-function. Therefore this paper improve the lock-function of first prototype, and report the outline of the new prototype. The new lock-function was composed by the solenoid, the rack and pinion gear. By using the solenoid, the unit realizes weight and cost saving and low power consumption, and it is more practical design than first prototype.