Abstract:
An actuator includes a displaceable portion, first to fourth artificial muscles, a pressure adjuster that changes a pressure of a fluid filled in the first and second artificial muscles, an open-close valve that allows a fluid to flow into or out of the third and fourth artificial muscles, and a controller that drives the pressure adjuster and controls the open-close valve. Each of the first to fourth artificial muscles includes a coiled elastic tube. In an outer circumferential surface of the tube, grooves are helically formed about an axis of the tube. The tube is filled with a fluid. In the first artificial muscle, a direction in which the tube is coiled is opposite to a direction in which the grooves extend helically. In each of the second to fourth artificial muscles, a direction in which the tube is coiled is the same as a direction in which the grooves extend helically.
Abstract:
An actuator converts the pressure of a fluid into a change in the length of the actuator and is formed such that an elastic tube is spirally wound. The tube is wound around the axis of the actuator. One or more grooves are spirally formed on the outer surface of the tube along the axial center of the tube. When the fluid contained in the inside of the tube is pressurized, a torsional force is applied to the tube along the spirals of the one or more grooves and causes the actuator to contract in the axial direction. Even when an external force acts in a direction in which the actuator is bent, the volume of the inside of the tube is not substantially varied. Accordingly, the actuator can be allowed to freely move in a bending direction.
Abstract:
An assist wear item is worn on a portion of a living body and has an inner surface brought into contact with the portion. The assist wear item includes assisting actuators, contact sensors, and a controller. Each assisting actuator is driven to expand and contract. The assisting actuators are linearly arranged along an expansion/contraction direction of a muscle at the portion. Each contact sensor detects a contact with an outer surface of the assist wear item. The contact sensors include a first contact sensor and a second contact sensor. The controller increases or decreases a driving power of expansion/contraction driving of an assisting actuator corresponding to a region ranging from the first contact sensor to the second contact sensor if the controller continuously receives a detection result indicating a contact from at least one contact sensor between the first and second contact sensors during a certain time period.