Yoshito Okada's research while affiliated with Tohoku University and other places

Publications (78)

Article
Full-text available
As considerable amounts of welding are required during ship construction, robotic automation is being promoted. However, current welding robots do not automate work in high or narrow places. One reason is that welding cannot be performed with sufficient accuracy because a welding robot with a torch cannot tow a heavy cable and thus may go off path....
Article
This paper describes a plant inspection robot team consisting of three types of robots that won the World Robot Summit 2020 plant disaster prevention challenge. There is a social demand to use robots for industrial plant inspection tasks to decrease the workload and risks of human operators. In this study, the authors developed a plant inspection s...
Chapter
In recent years, 3D concrete printing (3DCP) systems have been extensively developed in the construction field as a promising new technology. In particular, additive manufacturing (AM) systems using mortar are among the most promising methods. 3DCP has great advantages such as labor work saving at labor-intensive construction sites and creating com...
Article
In transporting a heavy load, instead of utilizing a conventional unmanned aerial vehicle (UAV), this research introduces the new scalable UAV design for lifting and transporting applications. The main concept focuses on reconfigurable control layers with multiple UAVs arranged in hierarchical order. Data transmission across layers is responsible f...
Article
Our team developed mechanism that aims securing regidity and reducing weight of UAV by constructing with box-shape objects. It is a mechanism that feeds out box-shaped objects one by one, and the transfer efficiency is improved by performing multiple transfers. In this paper, we describe the trial production and operation test of the individual fee...
Article
The authors have been developing a swarm robot system to automate long distance welding in narrow and high places, which cannot be handled by existing welding robots. In welding operations, it is necessary to tow not only the welding torch but also the cables that supply welding wire and gas to the torch. In addition, when welding in a narrow space...
Article
The authors aim to build an autonomous system that works in factories and shopping malls. Objects layout are designed for supporting human activities in such environments. This paper proposes a method of SLAM using objects layout constrains. The proposed method improves the accuracy of the objects layout map by using the objects layout constraints....
Article
Most of the welding robots are either large and non-mobile manipulators or small vehicles that do not have an autonomous navigation function. Therefore, they cannot be used for long distance welding in narrow or high places. For this problem, this paper proposes a swarm robot system for automating long distance welding in narrow or high places. The...
Article
Although slopes or cliffs are needed to be inspected every 5 years, this law is not observed now. Due to few artisans and danger of dropping down, there are demands of using robots to inspect slopes or cliffs. Because the slope or cliffs surface is usually huge, rough, uneven, sometimes not easy to access, and has occasionally steps which have 300[...
Article
Currently, drone research and development has received significant attention worldwide. Particularly, delivery services employ drones as it is a viable method to improve delivery efficiency by using a several unmanned drones. However, regarding the takeoff and landing port of the drones, the continuous landing of multiple drones has not been realiz...
Article
In this paper, an autonomous spiral stair climbing method for tracked vehicles using the reaction force from side walls has been proposed. Spiral stairs are one of the most difficult terrains for tracked vehicles because of their asymmetrical ground shape and small turning radius. Tracked vehicles are expected to be used in industrial plant inspect...
Preprint
Currently, drone research and development has received significant attention worldwide. Particularly, delivery services employ drones as it is a viable method to improve delivery efficiency by using a several unmanned drones. Research has been conducted to realize complete automation of drone control for such services. However, regarding the takeof...
Article
Full-text available
This paper describes a wall deadlock evasion method for tracked vehicles. Wall deadlock is a phenomenon where the robot cannot rotate to the commanded direction when it collides with a wall, because the motion is restricted by the wall. The key idea behind solving this problem involves an adjustment of the rotation radius to generate sufficient rot...
Article
Our research team is developing a UAV with a passive rotating spherical shell whose purpose of inspecting bridge. The UAV with a passive rotating spherical shell can avoid crashes caused by contact with some objects. This UAV have been successful in inspecting under some bridges. But for now, there is no optimal controller that can be applied to th...
Article
This paper proposed skidding movement method for tracked vehicle that uses the wall reaction force. There is a demand for tracked robot to inspect in the plant automatically. In the plant, usually there are many obstacles such as stairs, steps, and so on. So, tracked robot is proper for plant inspection, because crawler has high road abilities. How...
Article
In this paper, the authors construct a motion generation method to avoid wall deadlock problem. Wall deadlock is a phenomenon that the robot cannot leave from a wall once it collides on it because collision force inhibits the motion. The proposed method is constructed directory from a static model of the tracked vehicle colliding with a wall.
Article
Aerial robotics is a fast-growing field of robotics and has been successfully used in various applications. Still, it faces many challenges such as dealing with unavoidable obstacles in a cluttered environment. Recently, a flying robot with a protective shell that can rotate passively was introduced. The passive rotating mechanism is intended to re...
Article
In our study, we developed AED Gripping System for AED transport UAV in order to deliver quickly to remote places. This system is structured by grippers and a gripping determination system. We introduced Permanent Electromagnets as gripper. The gripping determination system is necessary to confirm that the AED is delivered at the destination, becau...
Article
There are many proposals of propeller protection mechanisms and wheel mechanisms for multi-copter which running and flying by propeller thrust. In addition to being capable of normal flight, the propeller guard can be used as a passive wheel to allow traveling on the ground, walls, ceiling, etc. As a characteristic required for such a propeller pro...
Article
In this paper, we aim to inspect the upper structure using the camera mounted on the multicopter. For this purpose, we changed the placement of the propulsion equipment to prevent the aircraft from appearing on the camera , and created a 3-DOF tether that does not disturb inspections to prevent runaway. By changing the arrangement of the propulsion...
Article
We propose a method to distinguish the robot itself from the surrounding environment in the camera image mounted on the robot.In this research, we aim to detect robot itself by using only images of multiple scenes in which the robot itself and the different background are shown for comparison, and extracting similar areas by feature value. In this...
Article
Full-text available
Following publication of the original article [1], the authors reported that one of the authors’ name is spelled incorrectly. In this Correction the incorrect and correct author name are shown. The original publication of this article has been corrected.
Article
Today, robots are expected to be used for the inspection of infrastructures such as bridges. One important task in bridge inspection is to acquire clear images of its various parts for further damage evaluation. However, this task has not yet been completely realized because of the complexity of bridge structures. For this situation, a UAV with a p...
Chapter
Inspections by mobile robots are required in chemical and steel plants. The robots are required to ascend and descend stairs because equipment components are installed on different-level floors. This paper proposes turning motion for tracked vehicles on stairs. A characteristic of the proposed turning motion is that it is generated using the reacti...
Article
Inspections by mobile robots are required in nuclear power and steel plants. The robots need to climb and descend stairs because equipments are installed on difference levels. This paper proposes a turning motion on the stairs for tracked vehicles. A characteristic of the proposed turning motion is by using the reaction force from the safety wall....
Article
In this paper, we propose a motion control method of differential-drive wheeled robot to avoid wall-deadlock. We define the wall-deadlock problem as the cases that the robot cannot rotate to the desired dirrection because of the collision force from an obstacle. The proposed method generates rotational moment to the desired direction by adjusting r...
Article
In order to inspect the structures using multicopter, it is necessary to maneuver out of sight. In this paper, we made prototype of first person view video transmission device with a small time delay using spherical camera to teleoperate the passive rotating spherical shell multicopter out of sight. The proposed system contains a head mount display...
Article
In this paper, we report on an inspection system integrating vertically moving winches and a prototype inspection carrier in the development of the robot system that inspects the inner wall of a large boiler for power generation. We develop a mechanism that can raise and lower while maintaining the horizontal level of an inspection carrier using tw...
Article
This paper describes a method which make sharing search and rescue (SAR) dog's investigation activities. The search and rescue activity will be operated several organizations. Therefore, it is necessary for correct decision making to share SAR dog's investigation. The authors propose a sharing method using widespread high speed communication and in...
Article
In this chapter, we introduce modeling and control for wheeled mobile robots and tracked vehicles. The target environment is rough terrains, which includes both deformable soil and heaps of rubble. Therefore, the topics are roughly divided into two categories, wheeled robots on deformable soil and tracked vehicles on heaps of rubble. After providin...
Article
A typical UAV with a passive rotating spherical shell can provide protection while keeping the UAV stablethrough gimbal mechanism. However, the passive/random rotation and gimbal mechanism have some drawbacks when applied to a real-world mission such as for search and inspection in the event of a disaster. The random rotation of spherical shell wil...
Article
We propose a realtime image restoration method for aerial inspection images that are deteriorated by the occlusion of a passive rotating shall of an unmanned aerial vehicle (UAV). We use only one image as the input, detect joints of the UAV shell using feature-based object detection, reject outliers based on a sample consensus (SAC) approach and th...
Article
We have been developing the MAV with a passive rotating spherical shell for bridge inspection. However, there are issues such that the spherical shell occludes the environment in the on-board camera image, and can be hit by the hammering machine. Therefore, this paper proposes a method to estimate the rotation state of the passive rotating spherica...
Article
In this paper, we proposed an adhesion mechanism using an electro permanent magnet for unmanned aerial vehicles (UAVs). We aim to realize remote fixed-point observation by UAV with the proposed mechanism, by adhering to a metal object in the environment, instead of rotating propellers that consumes large amounts of power. We introduced the principl...
Article
We propose a method by which a micro air vehicle (MAV) can hover without propulsion power. In this paper, we describe the design of a magnetic adhesion mechanism and a winch mechanism for an MAV that is used to perform search operations inside buildings. An MAV equipped with these mechanisms can adhere to an iron ceiling and search for a long time...
Article
Quadrotor are expected to use in disaster investigation or infrastructure inspection. There are complex structure and narrow spaces in these field. In flight on such an environment, there is a high risk of crash due to contact with an obstacle. Therefore, this paper proposes a quadrotor with a rotating spherical shell. The shell can be rotated free...
Article
A battery powered MAV is used to search inside damaged building and plumbing. However, its flight time is from 10 to 15 minutes because of the limitation of battery. We proposed a MAV has adhesion mechanism to improve above problem. It can hover longer time without propelling by using adhesion mechanism and winch mechanism. In this paper, we evalua...
Article
On March 11, 2011, a massive earthquake (magnitude 9.0) and accompanying tsunami hit the Tohoku region of eastern Japan. Since then, the Fukushima Daiichi Nuclear Power Plants have been facing a crisis due to the loss of all power that resulted from the meltdown accidents. Three buildings housing nuclear reactors were seriously damaged from hydroge...
Article
We report recent results from field experiments conducted with a team of ground and aerial robots engaged in the collaborative mapping of an earthquake-damaged building. The goal of the experimental exercise is the generation of three-dimensional maps that capture the layout of a multifloor environment. The experiments took place in the top three f...
Conference Paper
We report recent results from field experiments conducted with a team of ground and aerial robots toward the collaborative mapping of an earthquake dam- aged building. The goal of the experimental exercise is the generation of 3D maps that capture the layout of the environment and provide insight to the degree of dam- age inside the building. The e...
Article
In disaster environments, rescue robots have been expected for searching victims and exploring target environments. Particularly, a mobile manipulator can be useful for exploration in unknown environment. However, in such target environments, there are chances to have a communication delay and narrow space problem for the manipulator activity. Ther...
Article
On March 11, 2011, a massive earthquake and tsunami hit eastern Japan, particularly the Tohoku area. Since then, the Fukushima Daiichi Nuclear Power Station has been facing a crisis. To respond to this situation, we began a project to redesign our mobile robots for disaster response missions. A key issue to be addressed was to check the radiation h...
Article
On March 11, 2011, a massive earthquake and tsunami hit eastern Japan, particularly affecting the Tohoku area. Since then, the Fukushima Daiichi Nuclear Power Station has been facing a crisis. To respond to this crisis, we considered using our rescue robots for surveillance missions. Before delivering a robot to TEPCO (Tokyo Electric Power Company)...
Article
Tracked vehicles are frequently used as search-and-rescue robots for exploring disaster areas. To enhance their ability to traverse rough terrain, some of these robots are equipped with swingable subtracks. However, manual control of such subtracks also increases the operator's workload, particularly in teleoperation with limited camera views. To e...
Article
In urban search arid rescue situations, a 3D mapping technology by rescue robots is very useful to plan rescue missions. Furthermore, it is important to obtain temperature information for discovering victims in disaster scenes. Therefore, we set our research object to construct a 3D thermography map by mobile robots. To realize the above, we fuse b...
Article
In the future, mobile robots may be able to assist rescue crews in search and rescue missions that take place in the dangerous environments that result from natural or man-made disasters. In 2006, we launched a research project to develop mobile robots that can rapidly collect information in the initial stages of a disaster. One of our important ob...
Conference Paper
Full-text available
Tracked vehicles are frequently used as search-and-rescue robots for exploring disaster areas. To enhance their traversability on rough terrain, some are equipped with “active flippers.” However, manual control of such flippers also increases the operator's workload, particularly for teleoperation with limited camera views. To eliminate this tradeo...
Article
Tracked vehicles are frequently used as search-andrescue robots for exploring areas affected by disasters. To enable good locomotion during search-and-rescue operations on rough terrain, some of those robots are equipped with active flippers. However, the manual control of such flippers requires a highly skilled operator, particularly when teleoper...
Conference Paper
Mobile rescue robots used in search and rescue missions must be able to navigate in unknown environments and map these environments. In such situations, three-dimensional (3D) data obtained by a laser range finder is very useful for supporting teleoperation of robots to locate victims and aid rescue crews in devising rescue strategies. However, whe...
Conference Paper
Full-text available
Mobile robots may be able to aid rescue crews in dangerous environments during search and rescue missions after natural or man-made disasters. In 2006, we began a research project to realize mobile robots that can gather information rapidly at the first stage of a disaster. 3D mapping, which can be an important aid for rescue crews in strategizing...
Conference Paper
Full-text available
For tracked vehicles moving over rough terrain, it is important to avoid rollovers and rapid motion. To realize smooth locomotion on rough terrain, some tracked vehicles are equipped with ¿active flippers.¿ Such flippers increase the traversability and stability of tracked vehicles. However, their control increases the operator workload, especial...
Article
For search and rescue mission, it is important for mobile rescue robots to navigate in unknown environments and to map them. In such situation, three dimensional information is very useful to support robotic teleoperations used in locating victims and aid rescue crews in strategizing. However, to obtain this 3-D information, the operators must wait...
Conference Paper
Full-text available
Localization and mapping are essential elements in the design of mobile robots used for search and rescue mission. Localization is a key-function of remote control and mapping in an unstructured environment. However, in general, odometry in tracked vehicles is ambiguous because of the track slippage. To solve this problem, we developed a three-dime...
Article
Gyro-based odometry is a robust and easy-to-use localization method for mobile robots. However, the Gyro-based odometry for tracked vehicles has difficulties to estimate its exact localization because of track-terrain slippage and gyroscopes' bias-drifts. To solve these problems, we propose an extended 3-dimensional odometry method for tracked vehi...
Conference Paper
Full-text available
Tracked vehicles have the advantage of stable locomotion on uneven terrain, and, as a result, such mechanisms are used for locomotion on outdoor robots, including those used for search and rescue. However, such mechanisms always slip when a tracked vehicle follows a curve, and the slippage generates large accumulated positioning errors in the vehic...