Evaluation of line-tracing controller of intelligently controllable walker

Abstract

Caster walkers are supporting frames with casters and wheels that are regularly used as walking-aids in hospitals, nursing homes, and by individuals. The casters and wheels of the walker provide mobility to elderly users. However, when the walker moves in unexpected directions, falling accidents often occur. These accidents pose a very serious problem and are one of the leading causes of secondary injuries and disorders. Caregivers support patients with impaired motor or sensory functions by standing next to them when they walk. The main interests of this study are the development of an intelligent walker and the realization of a safe walker for the elderly and disabled. In our previous study, we developed the intelligently controllable walker (i-Walker) that utilized compact MR fluid brakes in its wheels and a web camera. In addition, we had proposed a line-tracing controller for i-Walker, whose performance was evaluated by healthy subjects. In this study, three elderly subjects suffering from different disabilities used i-Walker, and we evaluate the effects of the line-tracing control in the elderly gaits. To perform this task, we installed on i-Walker a gait measurement sensor. The gait sensor measures the step lengths and stride widths of subjects, which we use in our evaluation. Each gait was evaluated on the basis of the positional error, reaching time, step length, and stride width. The results show that the line-tracing controller of i-Walker reduced positional errors, but increased reaching times. Moreover, the line-tracing control of i-Walker improved the balance in the step length and reduced the stride width of a subject suffering from imbalance motion caused by a fracture.

Hierarchical Shared Control of Cane-Type Walking-Aid Robot

“…A wearable Power-Assist Locomotor (WPAL) was invented for the lower limb [ 6 ]. Kikuchi et al [ 7 ] proposed an intelligently controllable walker (i-walker). Hirata et al invented a passive intelligent walker called “RT-Walker” [ 9 ].…”

Shape-Controlled Syntheses of Magnetite Microparticles and Their Magnetorheology

“…A magnetorheological (MR) fluid is a magneto-responsive soft material that undergoes a reversible transition from a liquid-like to a near-solid state under the influence of an external magnetic field (i.e., the MR effect) [1]. This property makes MR fluids good candidates for applications in mechanical systems such as passive MR dampers [2], haptic interfaces [3], and human-friendly robots [4]. This material is a two-phase system consisting of magnetic particles and a carrier liquid [1].…”

A clinical pilot study on posture stabilization via light contact with cane-type companion robot

“…These non-wearable robots do not constrain the leg movement of the user, and the walking ability of the elderly people can be evaluated in situations closer to the natural gait motions (unlike wearable systems with active forced assistance) using vital information. In [16], a device called intelligently controllable walker (i-Walker) has been introduced, which can analyze users' risk of falling with the force and position sensing information. In [17], a passive intelligent walker called RT-Walker has been proposed, which is composed of only passive elements such as servo-brakes to control the velocity of the walker according to the operation force applied by the user.…”