SIP is a national project for science, technology and innovation, spearheaded by the Council for Science, Technology and Innovation as it exercises its headquarters function to accomplish its role in leading science, technology and innovation beyond the framework of government ministries and traditional disciplines. The SIP addresses the most important social problems facing Japan, as well as contributes to the resurgence of the Japanese economy.
A large portion of today's infrastructure was built during the period of our high economic growth several decades ago and in recent years numerous cases of infrastructure deterioration have surfaced, presenting the danger of devastating accidents and other serious related issues. Infrastructure Maintenance, Renovation, and Management program will take advantage of world-leading information and robotics technologies to create systematized infrastructure management to restrain infrastructure lifecycle costs through preventive maintenance.
Passive Rotating Spherical Shell (PRSS) UAV＆Spider-copter
・Passive Rotating Spherical Shell UAV
Passive rotating spherical shell (PRSS) UAV is an unmanned aerial vehicle that can inspect floor slab and girders interval of aged bridges. PRSS can protect the MAV from the collision. Therefore, PRSS-UAV can fly even when it collides to the floor slab and the girders. PRSS-UAV can observe the close-up surface. These image data can be used to find crack, injury, and corrosion.
Spider-copter is a micro aerial vehicle that can relay radio and pictures for PRSS-UAV. It can adhere to girders of steel bridges by using a magnet. By stopping propelling motion, it can relay the radio and the pictures a long time at same position. Wide-view angle camera images, which are taken from on-board camera, can be used for the tele-operation of PRSS-UAV. It can expand the relay area by changing the location.
Laser Ultrasonic Visualizing Inspector「LUVI」
Laser ultrasonic visualization detection technology,using irradiation and scanning bya laser,visualizing ultrasonic wave propagation,analyzing the propagation image, detects defects inside the object. As a new testing technology,LUVI has attracted widely attention,since it can be applied to more ranges as well as used to test any complex shape.
Ultrasound is excited by a very weakly thermal strain,which occurrences when a pulse laser irradiates a surface of the object. The synchronized control to the laser,mirror and high-speed A/D converter on a PC，laser scans on the surface of the object in high-speed simultaneously, using a receiving sensor attached to a fixed point and a non-contact receivable laser probe to detect the ultrasonic wave propagation signal,which can be recorded on the PC through an ultra-low-noise amplifier as well as the high-speed A/D converter.Recorded ultrasonic signals which are a plurality of waves toward the receiving sensor from the laser excitation point, the propagation image can be reconstructed by utilizing the reciprocity of the ultrasonic wave propagation.In the visualization method,neither the incident angle nor the focal distance keep a constant.This system evaluates the ride comfort of roads in terms of International Roughness Index (IRI) at low cost by using MEMS-type sensors of smartphones installed on ordinary vehicles.
This system consists of the measurement hardware/software and analysis software. Measurement software,i-DRIMS,developed as iOS application program,obtains acceleration,angular velocity,GPS information and other data.
Bridge monitoring system ／ Bridge trafficability assessment system
・Bridge monitoring system
This system is developed to evaluate performance differences among structures,which are usually not observed in visual inspections.Wireless sensor networks installed on bridges of similar designs collect acceleration responses of the bridges. Vibration frequencies, amplitudes,and deflections of these bridges are estimated and compared with each other to find outliers.Highway bridges constructed around the same time and local bridges are the main target. The outliers,once found,will be further investigated in detail by other means. Elemental technologies of low-power wireless sensor network and outlier screening are the key points of this system.Wireless sensor network hardware include ultralow-power version,high-accuracy version,and general purpose version.These versions cover different sensor lifetimes and structural characteristics.A robust and simple multihop communication protocol is developed considering complex communication environment in and around structures.
・Bridge trafficability assessment system
This system assesses bridge trafficability right after earthquakes remotely.
This system can be installed on multiple bridges, which allows the management of bridges in large areas all together. The system can also be used to obtain natural frequencies when installed at mid span points.
Tsukuba Technology Co., Ltd