-Omni-Directional Mobile Wheelchair-


@We are developing the wheelchair equipped with the capability to move in all the directions. Since this project started in 1998, several systems, such as operational support system of users, control system for comfortable driving and novel mobile mechanism, have been developed.

Study of Operational Support Systems

@Wheelchair is used by not only disability person (while sitting in the seat) but also care-giver. There are barriers, such as collision to obstacle or wall, increase of the load for nursing and discomfort of operation, to realize comfortable and safety operation. Therefore, in our laboratory, the operational support system for both users is developed.

‘Obstacle Avoidance using Haptic Joystick

@This is a system which can provide safety operation for "self-operation" passenger. We developed a system that combines environmental recognition system with Laser Range Finder and Haptic (active) Joystick. Haptic sense is effective to make a passenger notice the existence of danger of collision during the operation. The passenger can detect the environmental condition through the haptic joystick and it would have an effect to encourage to avoid a collision.

‘Power-assist System for Care

@Wheelchair is used by care-giver. Power-assist control system is effective to such a person who does not have enough power to push the wheelchair. Especially, this system produces an effect at movement on the slope. Our study concentrates to development of the system which can control the system without discomfort. It contains the directional or intentional reasoning and skill-level evaluation of human being.

Study of Omni-directional Mobile Mechanism

@Omni-wheel is the most common mechanism to realize the omni-directional movement because it can realize such a movement very easily, and it is an advantage of this mechanism. However, this kind of mechanism contains disadvantages that it can not climb the difference in level on the floor and it generates vibration and noise because of its structure. For that reasons, we developed a novel mechanism named "Differential Drive Steering System: DDSS". High mobility capability and energy saving are realized by combining the caster drive mechanism that can realize omni-directional movement by usual tire, and the differential gearing that is used as a power-distributing mechanism. Although planetary gearing mechanism or bevel gear mechanism is usually used to the differential gearing mechanism, we developed spur-gear typed differential gearing mechanism to realize more effective distribution ratio of loads as shown below.
in the case of "Driving"
in the case of "Steering"

Other Omni-Directional Mobile Robots

@As other applications of omni-directional mobile robot, we are developing "Omni-Directional Mobile Bed" and "Omni-Carrier".

‘Omni-Directional Mobile Bed

@We developed Omni-Directional Mobile Bed which can be controlled with power-assist system. If we want to carry the bed to another room at the hospital or nursing-care facility etc., we would carry it by more than two people. This system provides the system which can carry the bed alone. Furthermore, safety operation in narrow space or doorway can be realized by combining the collision avoidance.


@Omni-Carrier is a novel omni-directional mobile platform. The round shape body does not make the front direction of a mobile robot determine, the operator can decide the front direction arbitrarily. Power-assist control system is applied as an operational interface, and by combining with the round shape body, intuitive operation is brought in the operator.

Omni-Directional Mobile Bed

Research Theme



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