A Novel Actuator System Combining Mechanical Vibration and Magnetic Wheels Capable of Rotational Motion Using Shape Memory Alloy Coils

Abstract

In every country, large steel bridges, such as cable-stayed bridges, are actively being constructed, and the number of such bridges has been progressively increasing. These bridges are often inspected using drones, but inspection techniques have not been established because of strong winds and thunder. Therefore, robots capable of working in difficult environments are desired. In the present study, a prototype of a rotary actuator system combining two iron disks and two electromagnetic-vibration-type actuators was fabricated. A new operation principle was developed that drives the system using the reaction force of the vibration-type actuator. Two shape memory alloy coils and two friction pads were integrated into the system to enable it to carry out turning operations, which were successfully demonstrated. The proposed actuator system can thus move in any direction. In addition, with this actuator system, both slide-on-ceiling and wall-climbing motions are possible.

A New Type of Rotary Magnetic Actuator System Using Electromagnetic Vibration and Wheel

“…By using the silicone rubber to reduce the interference between the vibration component, the propulsion characteristic of the actuator system could be doubled compared to that of the single-wheel actuator. Furthermore, when the same electric power was applied to the electromagnet of the vibration component, the result of the previous study [15] having a permanent…”

“…The operation principle has already been described in the previous study [15]. This paper has described it in more detail.…”

“…As adsorption methods for inspecting structures, the negative pressure of a pump [1], the wind force generated by a propeller [2], the force generated by a flexible rubber [3], a claw gripper [4][5][6], the adhesive force of a suction cup manufactured from a sponge [7], control of the attractive force of an electromagnet inserted in it [8], adhesive materials [9,10], and a permanent magnet and the magnetic wheel [11][12][13][14] have been proposed. The authors have proposed a new type of a magnetic-wheel-type actuator capable of movement with a new motion principle [15]. Especially, magnetic-wheel-type methods are an effective means for the movement of iron structures, such as cable-stayed bridges.…”

“…In the present study, a new type of a magnetic wheel actuator combining two iron disksan electromagnet and a vibration component proposed by the authors [16][17][18]-was developed. Compared to the previous study [15], the magnetic wheels were replaced with permanent magnet types from electromagnet types. A prototype system was developed in which two actuators were connected, and on-off control of attractive force was possible.…”

“…A prototype system was developed in which two actuators were connected, and on-off control of attractive force was possible. Compared to the previous study [15], it was designed so that an attractive force could be controlled on-off by replacing the permanent magnet type with an electromagnet type. In an experiment, a magnetic wheel actuator system with high-propulsion characteristics in which two actuators were connected by a flexible material was prototyped.…”