Unmanned Construction Research Articles

Achievement and Future Prospects of ICT Construction in Japan

[abstFig src='/00280002/02.jpg' width=""300"" text='Unmanned construction system' ]Population projections for Japan suggest that the production-age population, ages 15 to 64, will be 70% or less in 2045 than that of today. In the field of construction, such rapid reductions in the production-age population will bring about a severe reduction in the number of workers as well as budget cuts in infrastructure investment due to the decrease of tax revenue. At the same time, infrastructure, which has already been constructed, is now due for maintenance and approaching its renewal dates. Therefore, the task of stably providing infrastructure for society into the future will be more difficult than ever. In the field of construction, more complex projects will have to be carried out with limited manpower and budgets. This problem will be addressed, not by an extension of existing means, but by innovations in construction technology. ICT (Intelligent Construction Technology) is expected to be a promising tool to meet these future needs. This article discusses current conditions and future prospects for a new construction model utilizing ICT in Japan.

Research on Superimposed Terrain Model for Teleoperation Work Efficiency

[abstFig src='/00280002/08.jpg' width=""300"" text='Superimposed terrain model in operator's view image' ]In recent years, unmanned construction based on the teleoperation of construction equipment has increasingly been used in disaster sites or mines. However, operations based on teleoperation are based on 2D images, in which the lack of perspective results in considerably lower efficiency when compared with on-board operations. Previous studies employed multi-viewpoint images or binocular stereo, which resulted in problems, such as lower efficiency, caused by the operator's need to evaluate distances by shifting his or her line of sight, or eye fatigue due to binocular stereo. Thus, the present study aims to improve the work efficiency of teleoperation by superimposing a 3D model of the terrain on the on-board operator's view image. The surrounding terrain is measured by a depth image sensor and represented as a digital terrain model, which is generated and updated in real time. The terrain model is transformed into the on-board operator's view, on which an artificial shadow of the bucket tip and an evenly spaced grid projected to the ground surface are superimposed. This allows the operator to visually evaluate the bucket tip position from the artificial shadow and the distance between the excavation point and bucket tip from the terrain grid. An experiment was conducted investigating the positioning of the bucket tip by teleoperation using a miniature excavator and the terrain model superimposed display. The results showed that the standard deviations of the positioning errors measured with the superimposed display were lower by 30% or more than those obtained without the superimposed display, while they were approximately equal to those acquired using binocular stereo. We thus demonstrated the effectiveness of the superimposed display in improving work efficiency in teleoperation.

建機遠隔操縦に向けた車載カメラの防振性能の評価

建機遠隔操縦に向けた車載カメラの防振性能の評価

機械・土壌の相互力学モデルの構築を目的としたバケット掘削実験装置の開発と数値解析

The main scope of this research project is to establish a high-fidelity simulation framework for an unmanned construction system incorporated with an accurate interaction mechanics of bucket/crawler of the construction machine on loose terrain. The interaction mechanics in this research exploits two approaches: an empirical macroscopic method and a numerical microscopic one. The former one first measures dynamic responses of bucket excavation or crawler locomotion on terrain, and then formulates the dynamics with respect to terrain deformation. The latter one utilizes a computational method such as discrete/finite element methods to precisely clarify the physical response of terrain deformation. As a part of this project, this paper reports a development of a bucket experimental apparatus and its preliminary test results. A numerical simulation analysis using DEM/FEM of a bucket excavation is also presented.

土砂災害の初動対応を目指した無人建設機械の状態提示技術の研究開発

Our research goal is to improve a status display of information acquisition system for unmanned construction machines to conduct an initial response (within 1 month) of sediment disasters. One of our approaches is to fly a tethered multi-rotor UAV (unmanned aerial vehicle) that mounts a camera, and to obtain environmental information around the construction machine. In order to advance this idea, we conducted a simple flight test of our multi-rotor UAV around a constructed machine. In this paper, we report the initial test, and introduce our lessons learned.

Visibility Enhancement using Autonomous Multicamera Controls with Situational Role Assignment for Teleoperated Work Machines

The aim of this study is to provide a machine operator with enhanced visibility and more adaptive visual information suited to the work situation, particularly advanced unmanned construction. Toward that end, we propose a method for autonomously controlling multiple environmental cameras. Situations in which the yaw, pitch, and zoom of cameras should be controlled are analyzed. Additionally, we define imaging objects, including the machine, manipulators, and end points; and imaging modes, including tracking, zoom, posture, and trajectory modes. To control each camera simply and effectively, four practical camera roles with different combinations of the imaging objects and modes were defined: overview machine, enlarge end point, posture‐manipulator, and trajectory‐manipulator. A real‐time role assignment system is described for assigning the four camera roles to four out of six cameras suitable for the work situation (e.g., reaching, grasping, transport, and releasing) on the basis of the assignment‐priority rules. To test this system, debris‐removal tasks were performed in a virtual reality simulation to compare performance among fixed camera, manual control camera, and autonomous control camera systems. The results showed that the autonomous system was the best of the three at decreasing the number of grasping misses and erroneous contacts and simultaneously increasing the subjective usability and time efficiency.

Modeling of Operation Function of the Unmanned Excavator in the Deterministic Surfacing Process

Unmanned excavator has been developed for the improvement of operation efficiency and the decrease of economics cost, on which the researches have attracted widely research enthusiasms. Deterministic surfacing method is an effective technique for the intelligent control of the unmanned excavator, and the key point is modeling of operation function. Through analysis of operation process, kinematic trajectory of the relieving tool is obtained. By simplifying structures and parameters of the operation system, both cross-sectional line and 3D feature which represent character of the operation function are obtained. Modeling of the operation function will promote application of the unmanned excavator and supply experience for advanced control of other unmanned construction machines.

無人化施工におけるヒューマンインタフェースの作業効率評価

無人化施工におけるヒューマンインタフェースの作業効率評価

無人化施工用俯瞰映像提示システムの開発

無人化施工用俯瞰映像提示システムの開発

Visual Attention to Appropriate Monitors and Parts Using Augmented Reality for Decreasing Cognitive Load in Unmanned Construction

Visual Attention to Appropriate Monitors and Parts Using Augmented Reality for Decreasing Cognitive Load in Unmanned Construction

2P1-P04 遠隔重機作業の高度化に関する研究 : 拡張現実感を利用した映像の注視・解釈支援手法の開発

2P1-P04 遠隔重機作業の高度化に関する研究 : 拡張現実感を利用した映像の注視・解釈支援手法の開発

Modeling of Three-Dimensional Terrain Data for Intelligent Control of Unmanned Construction Machine in Deterministic Surfacing Process

Deterministic surfacing technique is an effective method for intelligent control of operation planning of the unmanned construction machine, and its foundation is the accurate modeling of the three-dimensional terrain data. According to the digital elevation model based on regular grid, the modeling of 3D terrain surface data is obtained. The evaluation of residual error is further investigated, which is quite important for the iterated operation in deterministic surfacing. Through revealing flow chart of the deterministic surfacing method, the importance of the modeling of terrain data and that of the evaluation of residual error are emphasized. The study on modeling of terrain data will promote application of the deterministic surfacing in intelligent control of unmanned construction machine.

Technology of Unmanned Construction System in Japan

<div class=""abs_img""><img src=""[disp_template_path]/JRM/abst-image/00260004/01.jpg"" width=""300"" />Bird's-eye view system</div> This paper describes the application of Japan’s most advanced unmanned construction technologies to disaster recovery operations. These technologies were originally R&D focused, but have continued to become increasingly sophisticated with invaluable realworld applications. This paper focuses on robotic and autonomous operations and ultra long-distance remote control. We detail unmanned construction equipment and systems operating in radiationcontaminated environments and examine the effectiveness of monitoring-image technology in improving the operational safety of construction machinery. Finally, future directions and prospects are described. </span>

Recent Trends and Issues of Volcanic Disaster Response with Mobile Robots

<div class=""abs_img""><img src=""[disp_template_path]/JRM/abst-image/00260004/04.jpg"" width=""300"" />Volcano observation robots </span></div> Typically, volcanic eruptions cause heavy damage in its vicinity area, and the eruption often continues for years. During this period, a restricted area is set up in the vicinity of the crater, in order to ensure the safety of people. Therefore, it is important for mitigation of volcanic disaster to realize observation of the eruption and mudslide-control construction based on teleoperation-type robotic technology. To promote development of such technologies, various types of volcano exploration robots have been researched and developed in Japan and overseas. With regard to volcanic observations, this paper presents conventional methods for volcanic teleoperated observation, and discusses technical issues and research topics for the future technologies, particularly, mobile robotics and flying robotics. With regard to mudslide-control construction, the paper describes the teleoperated construction system that has been developed at Fugendake of Mount Unzen, and discusses technical problems in current unmanned construction system to be solved in the near future. </span>

1P1-K02 遠隔重機作業の高度化に関する研究 : 作業状況に応じたロールアサインメントに基づく環境カメラの向き・画角調整(建設・解体ロボット・メカトロニクス)

1P1-K02 遠隔重機作業の高度化に関する研究 : 作業状況に応じたロールアサインメントに基づく環境カメラの向き・画角調整(建設・解体ロボット・メカトロニクス)

1P1-M01 ステレオカメラを搭載した移動ロボットによるオンライン三次元環境地図の構築に関する検討(建設・解体ロボット・メカトロニクス)

Execution in hazardous area needs teleoperation system, and unmanned construction system are adopted into many scenes. This system use many unredeemable cameras and a lot of onboard camera for understanding robots environment. Operators have to learn depth form a multitude of the screen shows robots or the surroundings. The operator needs good skill and experiences. To solve this problem, we must show environment to know something intuitively. In dealing with such situation, we will report about the system of make three dimensional map sequentially, using a remote control robot load with stereo camera, and also it shown by polygon mesh.

實現無人工地首部曲－塔吊機器人

實現無人工地首部曲－塔吊機器人

無人化施工におけるテレロボティクス

無人化施工におけるテレロボティクス

The Heisei Eruption of Mt. Unzen-Fugendake and Measures Against Volcanic Disasters

The Heisei-eruption of Mt. Unzen had started on November 17 in 1990 and continued in the beginning of 1995. Dangerous volcanic phenomena such as pyroclastic flows and debris flows had occurred intermittently during the eruption, resulting in 44 of casualties and 2,511 destroyed houses. Though no one had experienced and estimated the occurrences of such events, the central government of Japan and the Nagasaki prefecture government soon started to ensure the appropriate measures for reducing the expansion of disasters. The first approaches were preparation of hazard-map for evacuation and execution of temporary works such as sediment removal and sensor installation. Furthermore, they had developed many new methods such as unmanned construction and executed the measures to mitigate debris flows and pyroclastic flows disasters. The measures were based on three viewpoints; (1) We have to cope with various phenomena by them. (2) They should be executed in short term. (3) The safety of workers has to be ensured. Inhabitants, academic persons and administrators had coped with the Mt. Unzen volcanic disaster in cooperation. As a result of the execution of the measures, the safety zone of life in the Shimabara city was restored and the communities were reconstructed. Thus, the preventive measures in Mt. Unzen were successful. Recently there is destruction of social infrastructures by volcanic disasters in the world. I can introduce the volcanic sabo work executed by the central and local governments in Mt. Unzen as a model case of the mitigation or prevention measures against volcanic disasters.

Disaster restoration work for the eruption of Mt Usuzan using an unmanned construction system

(2002). Disaster restoration work for the eruption of Mt Usuzan using an unmanned construction system. Advanced Robotics: Vol. 16, Cutting Edge of Robotics in Japan 2002 (Disaster Response Robotics), pp. 505-508.