http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Temperature-constrained topology optimization of nonlinear heat conduction problems
Zhuang Chungang,Xiong Zhenhua,Ding Han 한국CDE학회 2021 Journal of computational design and engineering Vol.8 No.4
This paper presents topology optimization of nonlinear heat conduction problems with multiple domains and multiple constraints, including regional temperature and material volume for reducing temperature. Maximum approximation temperatures in the constraint regions are accurately and dynamically calculated, though temperature and temperature-dependent thermal conductivity change with the update of material distribution. A temperature measure with constant error to approximate regional maximum temperature is adaptive to different temperature ranges. A strategy of hole nucleation generation combined with the regional temperature constraints is presented for the level set-based topology optimization. The solid isotropic material with penalization (SIMP) and parametrized level set methods are compared for the temperature-constrained topology optimization. Finally, several numerical examples are solved by the SIMP and parametrized level set methods. The results demonstrate that the proposed approach can obtain intricate topological details and reduce regional temperatures for the nonlinear heat conduction problems.
A fuzzy-based impedance control for force tracking in unknown environment
Yichao Shen,Yan Lu,Chungang Zhuang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.10
Industrial manufacturing operations, such as grinding and polishing, are characterized by relatively constant contact force. In this article, a fuzzy-based adaptive impedance is proposed, which can grind or polish workpieces of different materials with constant contact force. The environmental parameters are estimated by iterative calculation with recursive least squares (RLS). The impedance parameters, such as damping and stiffness, are taken as the outputs of the fuzzy controller. The proposed force controller can track the desired force without the prior knowledge of the environment information. Experiments are conducted in finishing tasks using the self-developed industrial robot to verify the adaptive impedance control. The environmental parameters are instantly estimated for the following adjustment of the impedance parameters, and the real time contact force shows that the adaptive fuzzy logic impedance controller can achieve better performance with the oscillation below 2 N as the machining surface of the workpiece is not predefined.