PHM in Automated Manufacturing and TransportationPHM in Automated Manufacturing and TransportationPHM in Automated Manufacturing and Transportation
Chair: Prof. Jaewook LEE (GIST)
Fault Detection of Gearboxes in an Industrial Robot under Various Operating Conditions Mr. Yunhan KIM, Jungho PARK, Jong M. HA, Byeng D. YOUN and Jin-Gyun PARK (Seoul National University, Hyundai Heavy Industries)
In recent years, industrial robots have been widely used for manufacturing automation. The unexpected failures of the robots could bring about a significant amount of downtime loss due to suspension of the production lines. Fault detection and diagnosis for an industrial robot become one of the backbone technologies in the Industry 4.0. However, the industrial robots operate under variable speeds and loads. This makes fault detection for the industrial robot more challenging. Moreover, signals generated from one arm joint affect those from other joints mutually due to the multiple degree-of-freedom (DOF) motions of the robots. In this paper, we develop a fault detection method for a gearbox, which is one of the most critical components of an industrial robot. Both control and acceleration signals are used for the fault detection. Health data that represent a health state of the robot system are defined as the failure mechanisms of the gears are understood. The effectiveness of the proposed health data is demonstrated using a 6-DOF industrial robot with normal and faulty cases under various operating conditions in terms of rotating speed, rotating directions, number of DOF, different postures of robot arms, and loading condition.
A Solenoid Valve Multi-physics Model for Railway Braking System Diagnosis: Development and Validation Mr. Soo-Ho JO, Dongki LEE, Byeng D. YOUN and Hyunseok OH (Seoul National University, Gwangju Institute of Science and Technology)
Solenoid valves are an electromagnetically-operated valve that can be used to control the movement of air in railway braking systems. To develop a physics-based diagnostic model for fault detection, it is critical to build a valid model that describes the behavior of solenoid valves accurately. This study presents an experimentally-validated multiphysics analytical model to predict solenoid valve behaviors. The activation of solenoid valves is associated with multi-physics mechanisms that are coupled together. Electromagnetic, fluidic, and mechanical mechanisms are modeled with ordinary differential equations. The results from the multi-physics analytical models are validated with those from the experiments. The undefined parameters of the model are statistically calibrated. The proposed model can be promising for solenoid valve diagnostics in two aspects. First, the computational cost of the analytical model is extremely low in comparison with that of a commercial finite element method (FEM). Second, the model provides an insight regarding explicit relationship between the inputs and outputs of solenoid valves.
Design of Cyber-Physical Systems Architecture for Prognostics and Health Management of High-speed Railway Transportation Systems Mr. Zhiqiang ZHANG, Zongchang LIU, Guanji XU, Wenjing JIN and Jay LEE (CRRC Sifang Co., Ltd., University of Cincinnati, CyberInsight Technologies Co. Ltd)
The high-speed railway (HSR) transportation system in China has been growing rapidly during the past decade. In 2015, the total length of HSR in China has reached to 19,000 kilometers, and there are about 2,000 pairs of high speed trains operating daily. With the advancement of design and manufacturing technologies, the reliability and construction costs have been improved significantly. However, there is still great need for reduction of their operation and maintenance costs. With such incentive, a pilot project has been launched in CRRC to develop prognostics and health management system for rolling stock and railway infrastructures to transform the maintenance paradigm from preventive to predictive maintenance. With the expectation of task variety and big data environment in real-time monitoring of HSR operation, a Cyber-physical system (CPS) architecture is proposed as the framework for its PHM system. This paper first reviews the needs of HSR subsystems for predictive maintenance, and then present a concept design of the CPS-enabled smart operation and maintenance system.
Rub-impact and Misalignment induced Vibration of HP Rotor System in Aero-Engine Prof. Qingkai HAN, Pingping MA, Meiling WANG and Jingyu ZHAI (Dalian University of Technology, Dalian Jiaotong University)
The numerical simulations of vibration induced by rub-impact and misalignment happening on the high pressure (HP) rotor system of an aero-engine are achieved, and also confirmed by experimental measurements on a special designed test-rig. The simulation model of the rotor dynamics is set up by using of ADAMS, composes of both effective stiffness elements of two different elastic supportings and s rigid shaft. The local rub-impact happening between one disc and the casing shell, the front supporting misalignment are involved in the model. In the model, the rub-impact mechanism is expressed by the parameters of its stiffness and damping and friction, and the misalignment is simulated by changing the position of the front supporting. To change the running speed and the rub-impact or misalignment levels, the transverse vibrations of the discs and shaft of the HP rotor are calculated. The numerically simulated time-domain responses, the frequency spectra and the shaft-center trajectories are plotted and compared on the above different operating conditions. These simulation results are compared to explore the efforts on rotor vibrations of the rotating speed, rubbing stiffness or friction, and the misalignment displacement or angle. Finally, the simulation results are also consistent with the measured vibrations on the HP rotor test-rig, which confirms that the established model and simulation method and typical results are acceptable.