Aya Kaisumi

Regenerative brake control of cycling wheelchair with passive behavior

In this study, we propose a cycling wheelchair that assists the movement of patients with impairment of lower extremities. The wheelchair is a pedal-driven system, similar to a bicycle, moved by the pedaling force of the patients legs. Although the lower extremities of patients are impaired, they can use both legs to smoothly rotate the pedal. However, there are several barriers to use the cycling wheelchair in an outdoor environment such as steep slopes, steps, and obstacles. In this study, we develop a cycling wheelchair controlled by a regenerative brake system. The braking control provides several assistive functions including velocity control, gravity compensation, and step/obstacle avoidance. The regenerative brake system can also charge a battery during the braking control. However, in situations such as steep-slope climbing and emergency stopping, the regenerative brake cannot generate the required force/moment and an active control is required. In these situations, the control mode is altered from braking to active, and the assistive functions are invoked using the energy charged by the braking control. For safety reasons, we propose a passive motion control method of the cycling wheelchair, even if the wheelchair operates under active control. The proposed cycling wheelchair is validated in a series of experiments in this study.

Design of handling device for caging and aligning circular objects

In this study, we consider the development of a device for handling small parts for automatic product assembly in factories. Many robotic hands and one-degree-of-freedom grippers have been proposed as grasping parts; here, we focus on the shape of the tips of a handling device for picking up small parts robustly and agilely. In this research, we propose a concept for a handling device for picking up small round parts. In this concept, the handling device cages an object without letting the object escape from its tips before closing them completely and then grasps the object robustly at a unique position of the tips. Using this caging and self-alignment concept, the handling device can pick up objects robustly and agilely. In this paper, we focus on a method for designing the shape of the devices tips using the concept of caging and self-alignment of objects. We also develop the robust and agile pick-up device (RAPiD) with tips designed by the new method and present experimental results that illustrate the validity of the concept and the ability of RAPiD to handle small parts.

Pedaling assistive control method of cycling wheelchair for hemiplegia patients

The cycling wheelchair is a new type of mobility aid for lower-limb-disabled individuals. Patients can drive the cycling wheelchair by pressing the front pedals with their lower limbs. The device enables patients to effectively rehabilitate their disabled legs and partake in outdoor activities. However, lower-limb-disabled individuals cannot move both legs with equal ease. Typical hemiplegia patients can voluntarily move their healthy leg, but not their disabled leg. Consequently, some of these individuals pedal the cycling wheelchair mainly with their healthy leg, leading to overuse of the limb during their daily activities. This study proposes a pedaling assistive control method that adjusts the different capabilities of the healthy and disabled legs of hemiplegia patients. The proposed control method was applied to a cycling wheelchair with a servo motor for power assist. In experiments, the proposed method reduced the work required for pedaling in two common environments; a planar floor and an upward inclined surface.

Design of parts handling and gear assembling device

Many one-degree-of-freedom (1-DOF) grippers have been used in factories. This paper focuses on the design of the 1-DOF parts handling device for picking up small objects robustly and agilely and realizing assembly tasks. In our conventional research, we proposed a concept for the handling device, which cages an object without letting the object escape from its tips before closing them completely and then grasps the object robustly at a unique position of the tips. In this paper, we propose a method for designing the shape of the devices tips by considering not only the caging and self-alignment of the object but also the gear assembly task. We also develop the robust and agile pick-up device (RAPiD) with tips designed by the new method and present experimental results that illustrate the ability of RAPiD to handle and assemble gears.

Assistance control method for one-leg pedaling motion of a cycling wheelchair

Since the cycling wheelchair was introduced in the 2000s, we have focused on alleviating the over-use of healthy limbs that presents a problem to users. To this end, we have been developing assistance control for everyday users of cycling wheelchairs. In our previous research, we found that user load varies in different environments. Traveling resistance compensation control proved successful in counteracting in a range of environments. In the user-load investigation on cycling wheelchairs, the crank torque generated by pedaling was observed to be problematic for hemiplegic patients, who must pedal mainly with their healthy side. Futhermore, for patients able to bend one leg only, because the opposite limb is stiffened at the knee joint or physically absent, the cycling wheelchair is difficult to maneuver. This paper focuses on the crank torque during one-leg-pedaling and proposes a new assistance control.

Assistive motion control of cycling wheelchair based on investigation of load on user

Though several kinds of equipment such as wheelchairs and electrical wheelchairs exist to support lower limb disabilities, there were still problems because of disuse of lower limbs that limits effect of rehabilitation and also cause disuse syndrome. To overcome these problems, cycling-wheelchair was invented by Handa et al. It is a pedal-driven wheelchair and can be applied to most of the patients whose lower limbs could be bent. It is mainly used for rehabilitation in facilities that have plane floor and uphill with small angle. However, the device has a problem in everyday use, which it needs more force to travel through steeper uphill or level differences. In this paper, we conduct an investigation that targets lower limb disabilities and unimpaired persons to clarify the load on users when they overcome difficult environments by measuring tread force on pedals. The result showed that uphill costs the user large load that some of the users could not overcome the uphill. To overcome this situation, for the first step, we designed a travel-resistance compensation control for a cycling-wheelchair.