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Design and simulation for a hydraulic actuated quadruped robot
Xuewen Rong,Yibin Li,Jiuhong Ruan,Bin Li 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.4
This paper describes the mechanical configuration of a quadruped robot firstly. Each of the four legs consists of three rotary joints. All joints of the robot are actuated by linear hydraulic servo cylinders. Then it deduces the forward and inverse kinematic equations for four legs with D-H transformation matrices. Furthermore, it gives a composite foot trajectory composed of cubic curve and straight line,which greatly reduces the velocity and acceleration fluctuations of the torso along forward and vertical directions. Finally, dynamics cosimulation is given with MSC.ADAMS and MATLAB. The results of co-simulation provide important guidance to mechanism design and parameters preference for the linear hydraulic servo cylinders.
Planning and Execution of Dynamic Whole-body Locomotion for a Wheeled Biped Robot on Uneven Terrain
Yaxian Xin,Jiuhong Ruan,Yibin Li,Hui Chai,Xuewen Rong 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.4
To improve the adaptability of the wheeled biped robot (WBR) to uneven terrain, firstly an integrated modeling method for wheeled-legs is proposed. The under-actuated part is effectively restrained by defining the interaction force between the WBR and the trunk. The mapping relationship between the wheeled leg’s end force and the joint torques in the balanced state is built. Based on this premise, a control framework that does not rely on external sensors is proposed, and the trunk pose is used as the task space to plan the generalized force output of the wheeled legs and calculate the joint torques. Since the joint space position is not constrained, the leg wheels will be based on the terrain conditions and are adaptively stretched and adjusted back and forth. To further improve the terrain adaptability, a slope estimator and a stabilizer are constructed to deal with the attitude fluctuation caused by the sudden change of terrain. The control framework is proved to verify by simulations and experiment.
Resveratrol promotes mitochondrial energy metabolism in exercise-induced fatigued rats
Lou Xujia,Hu Yulong,Ruan Rong,Jin Qiguan 한국영양학회 2023 Nutrition Research and Practice Vol.17 No.4
BACKGROUND/OBJECTIVES: To investigate the effect and regulator y mechanism of resveratrol supplementation on the mitochondrial energy metabolism of rats with exercise- induced fatigue. MATERIALS/METHODS: Forty-eight Sprague-Dawley male rats were divided randomly into a blank control group (C), resveratrol group (R), exercise group (E), and exercise and resveratrol group (ER), with 12 rats in each group. Group ER and group E performed 6-wk swimming training with 5% wt-bearing, 60 min each time, 6 days a wk. Group ER was given resveratrol 50 mg/kg by gavage one hour after exercise; group R was only given resveratrol 50 mg/kg by gavage; group C and group E were fed normally. The same volume of solvent was given by gavage ever y day. RESULTS: Resveratrol supplementation could reduce the plasma blood urea nitrogen content, creatine kinase activity, and malondialdehyde content in the skeletal muscle, increase the total superoxide dismutase activity in the skeletal muscle, and improve the fatigue state. Resveratrol supplementation could improve the activities of Ca2+-Mg2+-ATPase, Na+-K+- ATPase, succinate dehydrogenase, and citrate synthase in the skeletal muscle. Furthermore, resveratrol supplementation could up-regulate the sirtuin 1 (SIRT1)-proliferator-activated receptor gamma coactivator-1α ( P G C -1 α)-nuclear respirator y factor 1 pathway. CONCLUSIONS: Resveratrol supplementation could promote mitochondrial biosynthesis via the SIRT1/PGC-1α pathway, increase the activity of the mitochondrial energy metabolism- related enzymes, improve the antioxidant capacity of the body, and promote recover y from exercise-induced fatigue.
Xudong Wu,Jingyu Huang,Shuhui Yu,Panpan Ruan,Rong Sun,Ching-Ping Wong 한국고분자학회 2020 Macromolecular Research Vol.28 No.4
Dielectric materials with self-healing property after the occurrence of detrimental events such as tearing or scratch are highly desired, which guarantees reliability and lifetime of the electric and electronic systems. Here, a self-healing covalently bonded titanium dioxide/polyurethane (TiO2/PU) nanocomposite with enhanced dielectric constant was prepared by in-situ polymerization based upon Diels-Alder reaction. The PU prepolymer was prepared from TiO2, poly(tetramethylene glycol) and 4,4-diphenylmethane diisocyanate. Then the linking between the prepolymer and Diels-Alder adducts of bifunctional maleimide blocked by furfuryl alcohol was carried out. The in-situ polymerization method allows the TiO2 filler, the PU polymer matrix, and the DA healing portion to be tightly connected, resulting in a stable nanocomposite system. Due to the reversibility of covalent bonds, the TiO2/PU nanocomposites exhibited thermal self-healing properties after being cut. The dielectric constant and loss, mechanical properties can be effectively restored to their original state after damage.
Direct ethanol production from dextran industrial waste water by Zymomonas mobilis
Ming-xiong He,Han Qin,Xiao-bo Yin,Zhi-yong Ruan,Fu-rong Tan,Bo Wu,Zong-xia Shui,Li-chun Dai,Qi-chun Hu 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.11
The direct production of ethanol from dextran industrial waste water was investigated by using Zymomonasmobilis via batch and semi-continuous fermentation mode. In batch fermentation, pretreated waste water (unsterilizedand sterilized), pH value (3.8 and 6.0), and Mg2+(with and without) was compared with OD600, sugar and ethanol con-centration. After 24 h fermentation, sugar in the dextran waste water was almost exhausted, and the amount of ethanolaccumulated reached 24.33-29.92 g/l, which is nearly 99% of the theoretical yield of ethanol. Kinetic parameters ofZ. mobilis in batch fermentation were also investigated. The raw dextran waste water was also used in semi-continuousfermentation. After 48 h fermentation, the production of ethanol was 28.65 g/l. These results indicated that dextranwaste water may be used as a candidate substrate and Z. mobilis could convert the raw material into ethanol directly.
Jiang-Ning Hu,Bin Shan,Ze-Yuan Deng,Jing Li,Ya-Wei Fan,Rong Liu,Zheng Ruan 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.6
A high-speed counter-current chromatography (HSCCC) method was developed for isolation of 5alkaloids from lotus (Nelumbo nucifera Gaertn.) leaves. The 2-phase solvent system of HSCCC composed of light petroleum-ethyl acetate-methanol-water was set up in 2-step separation process in the proportion of 3:5:3:5 for isolation of N-nornuciferine and armepavine, and in the proportion of 1:5:1:5 for that of anonaine, pronuciferine,and nuciferine. The purity of anonaine (14.6mg), pronuciferine (29.7 mg), N-nornuciferine (31.4 mg), nuciferine (22.1 mg),and armepavine (23.3 mg) isolated from 150 mg crude extract of lotus leaves were examined as 95.6, 88.2, 92.5,94.3, and 92.1%, respectively.