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This technical paper reports the development of an automatic defect detector utilizing deep learning for “polished skins”. Materials with a “polished skin” are used in the fabrication of the external plates of commercial airplanes. The polished skin is obtained by polishing the surface of an aluminum clad material, and they are visually inspected, which places a significant burden on inspectors to find minute defects on relatively large pieces of material. Automated inspection of these skins is made more difficult because the material has a mirror finished surface. Defects are broadly classified into three categories: dents, bumps, and discolorations. Therefore, a defect detector must be able to detect these types of defects and measure the defects’ surface profile. This technical paper presents details related to the design and manufacture of an inexpensive automated defect detector that demonstrates a sufficiently high level of performance.

The traction-drive integrated drive generator (T-IDG®) has been developed since 1999 to replace current hydrostatic transmission drive generators mounted on Japanese military aircraft. The T-IDG® consists of a generator and a half-toroidal traction-drive continuously variable transmission (CVT), which maintains a constant output speed of 24000 rpm, that is, a 400 Hz AC power supply. To cope with recent trends of more electric aircraft (MEA) and the need for weight reduction, a high-speed traction-drive CVT is advantageous over other transmissions. The torque on the half-toroidal variator is transmitted through multiple power rollers. The equal load sharing among power rollers is typically controlled by a mechanical hydraulic feedback system, whose stability is one of the main issues for the high-speed traction-drive CVT. Previous studies have shown that insufficient damping and stiffness of the mechanical hydraulic feedback system cause self-induced vibration.

In the development of a motorcycle frame, the balance between high performance and reliability and a short development period are important. In this study, a fatigue durability evaluation technique for a motorcycle frame was developed to enable highly accurate development within a short period of time. Furthermore, we developed a shaking table excitation system as a means to supplement the road test.

In the modern aircraft manufacturing, the cost reduction, the manufacturing time reduction, and the weight saving of aircraft are strongly demanded. The Refill Friction Spot Joining [1,2](FSJ, in other words FSSW, Friction Stir Spot Welding), which is one of innovative solid-state joining methodologies based on the Friction Stir Welding[3], is a promising technology that can replace rivets and fasteners. This technology is expected to offer cost reduction and weight saving for the aircraft manufacturing. In this study, to make stronger and reliable joints, the shoulder-plunging process of Refill FSJ was employed. The weldability of the Alodine or Chromic Acid Anodize coated materials along with a faying-surface sealant was investigated. The joint properties, such as tensile shear strengths and corrosion resistance, were evaluated.

The Advanced ECS is under development for the purpose of saving fuel, improving safety, and cabin comfort. In FY2006 study, basic components (i.e. MDC, OBNOGS, desiccant units, and CO2 removers) have been improved and their performances evaluated including resistance to environmental condition (i.e. vibration). In addition, the suitable system configuration for a 90-seats aircraft has been considered to evaluate the feasibility of the system. In this paper, we show the results of the evaluated performances based on prototype components, and the analytical study of a revised system configuration.

Hydraulic fluid (HF) specifications for mobile construction equipment called JCMAS HK and HKB have been established by the Fuels and Lubricants Committee of Japan Construction Mechanization Association (JCMA). The specifications are designated by two viscosity categories of single grade and multigrade. Each category has ISO viscosity grade (VG) 32 and 46. The JCMAS HK oils are recommended for use in hydraulic systems designed at pressure up to 34.3MPa(5000psi) and to heat hydraulic fluid up to 100 °C. These oils also provide wear control, friction performance, oxidation and rust protection, seal swell control and filterability performance. Two piston pump test procedures were developed to evaluate lubricating performance of these oils under high pressure conditions. The JACMAS HKB oils are classified as environmentally friendly oils due to the additional requirement for biodegradability.

In line with the increase in the output of motorcycle engines, there has been an increase in incidents of the seizure between shift fork and gear because of the increased thrust force. We designed a test method that uses actual shift forks to simulate actual sliding conditions, then used that test method to evaluate the feature of the shift fork sliding and the different shift fork surface treatments. The shift fork slid against the gear not as surface contact but as tilted contact. We selected the candidates from the view that the surface treatment of the shift fork contact surface to give it higher seizure resistance when in tilted contact is required. We evaluated chromium nitride thin film, diamond-like carbon thin film, molybdenum sprayed coating, and sulphonitriding, and molybdenum sprayed coating exhibited the highest seizure resistance. The conformability plays a significant role in the sliding between the shift fork and the gear.

Structures and Materials Research Center of the National Aerospace Laboratory of Japan (NAL) conducted vertical drop tests of fuselage sections of a NAMC YS-11 A-200 transport airplane. This test program is a part of research activities in NAL on the structural crashworthiness of transport aircraft. In addition a cooperative research related to this test program has been carried out by NAL and Kawasaki Heavy Industries, Ltd.(KHI). The main objectives of this program are to develop optimal numerical models for crash simulation of aircraft fuselage and to obtain background data by drop tests of full-scale fuselage sections under a controlled impact condition. Two sections of the fuselage structure with seats and passenger dummies were tested at different drop velocity to a rigid impact surface(concrete). Finite element models of the test articles for simulation of vertical drop tests were developed using a nonlinear dynamic analysis code, LS-DYNA3D.

The Structures and Materials Research Center of the National Aerospace Laboratory of Japan (NAL) conducted a vertical drop test of a fuselage section from a NAMC YS-11 transport airplane in December2001. This test program is a part of research activities in NAL on the structural crashworthiness of transport aircraft. In addition a cooperative research related to this test program was carried out between NAL and Kawasaki Heavy Industries, Ltd.(KHI). The main objective of this program is to develop optimal numerical models for crash simulation of aircraft fuselage and to obtain background data by drop tests of small-scale structural models and a full-scale fuselage section. Prior to the drop test of a full-scale fuselage structure, a trial numerical simulation on the crash behavior of a small-scale sub-floor structure was conducted by NAL using the explicit, nonlinear dynamic analysis code, LS-DYNA3D.

The authors developed an air-to-air surveillance system that acquires mutual position and informs the position to the pilot. This system transmits position information obtained by GPS via TDMA (Time Division Multiple Access) datalink. Position information received from other aircraft is shown on a display. If proximity condition exists, voice alert is activated. This system can be used as an support system for collision avoidance. This paper describes the outline of the system and flight test result. Two prototype systems were installed on two helicopters. The third system was installed on a ground vehicle. Flight tests were performed using these three systems.

The impact of inlet unstart phenomena on supersonic transport (SST) was investigated by wind tunnel testing. Inlet unstart condition was simulated by controlling the captured mass flow by the inlet. Unsteady pressures on the lower surface of wing and unsteady forces of the wind tunnel model were measured. Unsteady pressure measurement was carried out to detect shock wave motion. Unsteady force measurement by using both internal balance and accelerometers was to estimate axial/angular acceleration of airframe when inlet unstart was occurred. The pressure measurement data revealed that shock location fluctuated with dominant frequency although the controlled mass flow was steady. And it was analytically shown that the dominant frequency is corresponding to the first order frequency of organ pipe resonance.

This paper describes results of the thermal-hydraulic performance experiment system (THYPES) of the two-phase flow loop thermal control system using the test rocket which can maintain a gravity level of 10-4G for about six minutes. Feasibility study of this system had been conducted for loading into a experiment module of test rocket TR-IA No. 3. In 1991, engineering model of the experiment system was designed and manufactured in order to investigate its function, performance, and endurance against launching conditions. In 1992, flight model of the experiment system was designed and manufactured. The following tests were conducted so as to ensure the capability and compatibility of THYPES; functional test, performance test, environmental test, and interface tests between the experiment system and rocket avionics section. The experiment was performed on September 17, 1993 and the results are evolved.

The Japanese Quiet Short Take Off and Landing experimental aircraft named ASKA was developed and flight tested during 1977 till 1989. The control system hard and software were examined by the functional mock-up with using the actual hardware. The small longitudinal limit cycle was observed in the closed loop test when the Pitch Control Wheel Steering software was on in the mock-up testing. In this paper, first, the method to analyze and to expect the limit cycle based on the describing function was shown. The limit cycle was induced due to the nonlinearities in the automatic control mechanism. The nonlinearities in the hardware were examined to make the model to simulate the system on the computer. The method was shown effective to predict the limit cycle in the mock-up. Second, with using the flight measured dynamics, the limit cycle was concluded as on border line between existing and not, which coincides with the actual flight result.

“ASKA” developed by National Aerospace Laboratory (NAL) is a quiet, short take-off and landing (QSTOL) research aircraft adopting upper surface blowing (USB) concept as a powered high lift system. To achieving sufficient STOL performance by augmenting stall angle of attack and roll control power, blowing BLC technique was applied to the outboard leading edges and ailerons.Supplied high pressure air to save the BLC piping space,the BLC system which was fit for use of high pressure air was developed. The BLC system, in which BLC air is discharged by a series of discrete jets from small drilled holes (0.8 ∼ 3.0 mm in diameter) arranged in a raw, is one of the unique features of the aircraft. In this paper, the summaries of aerodynamic development of the BLC system are described except for the air piping system.

“ASKA” is a STOL airplane with Upper Surface Blown type (USB) flaps used to perform research on powered lift technology developed by the National Aerospace Laboratory (NAL). ASKA has four high bypass ratio turbofan engines mounted above and forward of the wings, hydraulically actuated flight controls, and the Stability and Control Augmentation System (SCAS). The SCAS is a triple redundant system with three digital computers. In order to develop and evaluate its control laws, flight simulator tests have been conducted for 9 years during the design phase. Four flights have been devoted to evaluate functions of the SCAS and the control laws. The significant features of the control laws are to realize satisfactory flying qualities in the deep backside region at low airspeeds.