摘要：This paper presents a control algorithm for push recovery, which particularly focuses on the hip strategy when an external disturbance is applied on the body of a standing under-actuated biped. By analyzing a simplified dynamic model of a bipedal robot in the stance phase, it is found that horizontal stability can be maintained with a suitably controlled torque applied at the hip. However, errors in the angle or angular velocity of body posture may appear, due to the dynamic coupling of the transla- tional and rotational motions. To solve this problem, different hip strategies are discussed for two cases when （1） external dis- turbance is applied on the center of mass （CoM） and （2） external torque is acting around the CoM, and a universal hip strategy is derived for most disturbances. Moreover, three torque primitives for the hip, depending on the type of disturbance, are designed to achieve translational and rotational balance recovery simultaneously. Compared with closed-loop control, the advantage of the open-loop methods of torque primitives lies in rapid response and reasonable performance. Finally, simulation studies of the push recovery of a bipedal robot are presented to demonstrate the effectiveness of the proposed methods.

摘要：The tokamak start-up is a very important phase during the process to obtain a suitable equalizing plasma, and its governing model can be described as a set of nonlinear ordinary differential equations（ODEs）. In this paper, we first estimate the parameters in the original model and set up an accurate model to express how the variables change during the start-up phase, especially how the plasma current changes with respect to time and the loop voltage. Then, we apply the control parameterization method to obtain an approximate optimal parameters selection problem for the loop voltage design to achieve a desired plasma current target. Computational optimal control techniques such as the variational method and the costate method are employed to solve the problem, respectively. Finally, numerical simulations are performed and the results obtained via different methods are compared. Our numerical parameterization method and optimization procedure turn out to be effective.

摘要：With the development of high-speed railways in China,more than 2000 high-speed trains will be put into *** and efficiency of railway transportation is increasingly *** have designed a high availability quadruple vital computer (HAQVC) system based on the analysis of the architecture of the traditional double 2-out-of-2 system and 2-out-of-3 *** HAQVC system is a system with high availability and safety,with prominent characteristics such as fire-new internal architecture,high efficiency,reliable data interaction mechanism,and operation state change *** hardware of the vital CPU is based on ARM7 with the real-time embedded safe operation system (ES-OS).The Markov modeling method is designed to evaluate the reliability,availability,maintainability,and safety (RAMS) of the *** this paper,we demonstrate that the HAQVC system is more reliable than the all voting triple modular redundancy (AVTMR) system and double 2-out-of-2 ***,the design can be used for a specific application system,such as an airplane or high-speed railway system.

摘要：In order to enhance the glutathione peroxidase（GPX） catalytic activity of the selenium-containing single-chain variable fragments（Se-scFv）, a novel human scFv was designed on the basis of the structure of human antibody and optimized via bioinformatics methods such as homologous sequence analysis, three-dimensional（3D） model building, binding-site analysis and docking. The DNA sequence of the new human scFv was synthesized and cloned into the expression vector pET22b（＋）, then the scFv protein was expressed in soluble form in Escherichia coli BL21（DE3） and purified by Ni2＋-immobilized metal affinity chromatography（IMAC）. The serine residue of scFv in the active site was converted into selenocysteine（Sec） with the chemical modification method, thus, the human Se-scFv with GPX activity was obtained. The GPX activity of the Se-scFv protein was characterized. Compared with other Se-scFv, the new human Se-scFv showed similar efficiency for catalyzing the reduction of hydrogen peroxide by glutathione. It exhibited pH and temperature dependent catalytic activity and a typical ping-pong kinetic mechanism.