Papers by Keyword: Dynamic Performance

Abstract: The components of spindle system are key components in ultra precision machine tool. According to the characteristics of the machining process of vertical hydrostatic spindle system for ultra-precision fly cutting machine, the mass- stiffness model of the spindle system is established. This paper describes a system for the analysis of the spindle system under the action of external shocks. The use of the state space method is discussed and an example is given. The influence law of vibration frequency is obtained for the various mass and stiffness value of the spindle system components.

Abstract: In order to improve the dynamic characteristic of regulating valve system based on traditional fuzzy PID, a control strategy was presented and this method combines fuzzy PID and improved GA (genetic algorithm) to optimize fuzzy rules. Finally a simulation was carried on in MATLAB. The results show that: Compared with the traditional PID, the fuzzy PID enables the system to achieve better dynamic characteristics.

Abstract: The dynamic performance of the 12m span prestressed concrete beam is analyzed by finite element method. Based on the finite element analysis, with the change of the peak dynamic load, the risetime of dynamic load and the reinforcement ratio of prestressed reinforcement, the change laws of mid-span maximum deflection and the maximum stress of prestressed reinforcement in prestressed concrete beam are studied. At the same time, have further understanding to the stress and deformation of the prestressed concrete beam under explosive load. It can provide references for study on dynamic performance of the prestressed concrete beam under explosive load.

Abstract: For a plug-in hybrid electric vehicle equipped with Automated Manual Transmission (AMT), Dynamic Programming (DP) algorithm is used to improve the energy economy of the vehicle under the dynamic performance. Meanwhile, the energy consumption curve of vehicle and the operating points of engine under the driving cycle are obtained. From the results, the operation can be divided into two phases which are pure electric driving mode and hybrid driving mode. Then, compare the consumption in the two phases of hybrid electric vehicle with that of pure electric vehicle and traditional fuel vehicle separately. Finally, through calculation, the dynamic performance of the plug-in hybrid electric vehicle is also verified.

Abstract: The control system performance requirement was divided into three parts. They were the stability, rapidity and accuracy. The time-frequency domain analysis in the requirements of three performance were measured through quantitative performance index. The mutual restriction of time-frequency performance and system characteristic parameters of normal second order was discussed. The correlation of system time-frequency performance index was established. The relationship between time-frequency performance indexes in standard two order system was extended to higher order system. The mutually constraining and time-frequency correlation between each performance index was obtained by analysis and calculation. The work had been done above had practical significance to reflect the system dynamic performance in different analytical domains.

Abstract: The stiffness of transmission mechanism, assembled joints and moving platform, the compressibility of oil, and the load inertia of hydraulic Stewart mechanism will cause synthetically mechanical and hydraulic resonance problems, which will directly influence the system dynamic performance. The natural frequency and local dynamic isotropy index are adopted to evaluate dynamic performance. The variation trends of performance indices with configuration and inertia parameters are analyzed, and general optimal design rules and conclusions are obtained.

Abstract: In order to reduce fuel consumption and ensure dynamic performance of the car, an automotive powertrain optimization algorithm was presented in the paper. Firstly, the evaluation index of automobile dynamic performance and fuel economy were introduced. Then, the objective function was built, and the transmission and main reducer transmission ratios were designed as variables, and parameters of the vehicle transmission system were optimized by using the genetic algorithm. Finally, a vehicle simulation model by SimulationX software was established, and the power and economy performance before and after optimization were compared and analyzed.

Abstract: Knowledge about dynamic performance is very important for a control system. When carrying out static performance of a mobile robot, the sensing distance of various materials is established. However, based solely on this factor for controlling the mobile is not exact. Because in fact, many factors will influence to mobile robot controlling, they are determined by the relationship between the physical quantity in the measurement. Through a detailed study of theoretical knowledge and by some empirical methods of the conveyor system, we can determine the relationship of the dynamic parameters, such as: velocity, sensing distance, dimension of material, thickness of material, and so on. Experimental results demonstrate that the shape as the output signal depends on the type of sensor being used. To research the scope of the mobile robot, an analog proximity sensor is optimal, and to identify the output signal ON or OFF, the selection of digital sensor is better than an analog sensor. This is as a basis to improve the theoretical knowledge of mobile robot controller through the proximity sensor. Simultaneously, with these results, mobile robot is able to sense its world and change its behaviour on that basis.

Abstract: Designed new table for large floor boring and milling machine, used ANSYS to optimize the structure of the table as a whole. According to the contours of removable material the materials which can be removed, obtained the inner ribs layout of table and the sand holes location of rib plate. Dynamic optimization variables on basic ribs cell, studied the effect of steel lattice structure parameters influenced on the natural frequency of the lattices and the related parameter of lattices influenced on whole table, to get the ideal rib lattice structure after optimizing again. Optimized bench can reduce quality, increase rigidity and dynamic performance.

Abstract: In this paper, In view of body frame of a flying car, the dynamic performance was studied.Firstly, geometry model of the body frame was built by CATIA software. Secondly, plotted in girding form was established by ANSYS software. Thirdly, loading and restraint were added on model and dynamic characteristic was analyzed. Finally, a better conclusion was obtained.