Advanced Materials Research Vols. 466-467

Abstract: Primary mirror’ surface figure is affected by supporting structure obviously. Especially for large-aperture telescope, the surface figure is significant because of primary mirror’ self-weight. For the requirement of the usage, it’s necessary to minimize the surface figure from self-weight by reasonable supporting scheme. The text optimized support point and force of radial support to minimize the surface figure by finite-element software. At the same time, it studied the relationship between support point and counterweight to reduce the weight of support structure. At last, it gave the optimal solution.

Abstract: In this paper, a four degrees of freedom half body vehicle suspension system is developed .The Radial-Basis Function network algorithm is used to control the suspension system. With the aid of software Matlab/Simulink , the simulation model is achieved. A lot of simulation work is done. Simulation results demonstrate that the proposed active suspension system proves to be effective in vibration reduction of the suspension system.

Abstract: Synchronization torsion bar is a key part in independent and dependent impression mechanism which ensures synchronization motion at both ends of blanket cylinder. Due to frequent action of the mechanism in high-speed printing, synchronization torsion bar would cause huge impact torque so as to affect parallel shifting of blanket cylinder and uniformity of printing impression. Based on structure features and force of synchronization torsion bar, finite element model of synchronization torsion bar was established by adopting structural mechanics and finite element method, then static stiffness of synchronization torsion bar was solved by adopting principle of minimum potential energy. The result of computation shows that the maximum torsion deformation of torsion bar in X direction happens at the left connection point. Because the deformation is very small, the bar can meet the requirements that blanket cylinder.

Abstract: In this paper, a method of embedded system with multi-processor is proposed, so as to satisfy the requirement of strong real-time property, high computational performance and multi-task function of the flight control system. In addition, in order to solve the problems of unknown aerodynamic disturbance and weight uncertainties during flight, a hybrid control method based on sliding mode control (SMC) and model referenced adaptive control (MRAC) is proposed. Through the Lyapunov stability analysis, it’s proved that the controller is stable. Various simulations were performed and several experiments on the quadrotor UAV validate the control strategies.

Abstract: This paper investigates symbolic reachability issue of multirate hybrid systems. To this end, a constraint system called multirate zone is formalized for the representation and manipulation of multirate automata. To represent multirate zones, a data structure difference bound matrix for multirate zones is defined. In addition, to handle unions of multirate zones and data sharing, a BDD-like data structure multirate hybrid diagram is also defined. These enable us to do symbolic reachability analysis of multirate automata in an efficient way.

Abstract: The traditional quality analysis system has many disadvantages such as the bulky, expensive, fixed functional modules, poor extension, monotonous display etc. Combined with the virtual instrument technology, the paper propose design ideas of instrument Virtual power quality analysis based on LabWindows/CVI, including design of hardware circuit and software, obtain harmonic amplitude and phase by making use of fast Fourier transform. The analyzer has high accuracy, stable, and good anti-jamming performance, meet the electric power system testing requirements.

Abstract: Circulating fluidized bed combustion is a widely used technology because of its ability to burn a wide variety of fuels efficiently and in an environmentally acceptable manner. To guarantee optimal combustion performances, combustion stability is essential. This paper proposes a comparative approach to define a suitable control strategy for an accurate control of fuel combustion. Several control laws are therefore defined and applied on a dynamic nonlinear model, based on a pilot plant and representative of the main combustion phenomena: a conventional PID, a linear optimal control, a robust H∞ approach and a nonlinear control.

Abstract: In order to study the force mechanism and reinforcement effect of high-pressure second grouting method in leading support of soft-fracture wall rock, with the example of Heishiling highway tunnel construction at the shallow depth and crushed zone of the tunnel’s exit, which belongs to Zhangshi highway in Hebei province, by Three-Dimensional Numerical Simulation of GTS (Ground and Tunnel Analysis System), monitoring and surveying method, force mechanism and wall rock convergence were simulated and measured experimentally. The results showed that ductule high-pressure second grouting combined with double side-wall heading excavation method achieved good results, the maximal vault subsidence is 18.5mm, the maximal uplift value of inverted arch is 17.8mm, and the maximum displacement value on both sides of the wall is 15.9mm.

Abstract: Aiming at the optimization design of spindle, this paper introduces deflection constraint, strength constraint, corner constraint, cutting force constraint, the limit of torsional deflection, boundary constraint of design variable, dynamic property constraint , realizes the expression of the mathematical model of the spindle optimization design. Through the introduction of the real number code rule, the selection operator is built by adopting the optimum maintaining tactics and proportional selection, the crossover operator is built by using the method of arithmetic crossover and the mutation operator is built by using the method of uniform mutation. In the platform of VC++, the system of spindle optimization design based on GA is built. The analysis of the example shows that using the genetic algorithm to optimize the spindle can ensure the convergence of the optimization course, expand the search space, and the effect of optimization is obvious.

Abstract: The transient flow field is needed in order to predict the aerodynamic noise of an automotive HVAC duck by conventional methods. However, it is time-consuming when are several improved schemes .To solve the problem, schemes with large sound power can be discarded using Broadband Noise Source (BNS) model at first. Then, the best scheme can be found after the transient flow simulation .In this paper, an automotive HVAC duck is used as an example. Firstly BNS is used to predict which scheme is noisier, secondly the aerodynamic noise is computed using Fluent coupled with Sysnoise. At last they come to the same conclusion. The simulation results indicate BNS model can be used to find which scheme is the best without computing the transient flow field. So it can shorten the cycle of developing new products.