Abstract: This paper has introduced electromechanical coupling characteristics in portable facility for bearing load, considered model ,according to legs supporting gait when people walking, established the load torque compensation model , and a mathematical model of knee position control system which is made of the servo valve, hydraulic cylinders and other hydraulic components, designed hydraulic cylinder position control loop in case of existing load force interference compensation, and used the method of combining the PID and lead correction network for frequency domain design ,ensured system to meet a certain stability margin. The simulation results show that this position control method can servo on the knee angular displacement of normal human walking, reached a certain portable facility bearing load and assistant power effect, at the same time, met the needs of human-machine coordinated motion.
Abstract: Aiming at the defects of current thermal mass flow sensor, we developed a novel thermal gas mass flowmeter based on the principle of constant power, which consists of semiconductor sensors and a microcontroller as the core controller. The design plan is carried out on the basis of simple structure and reasonable cost, which maximizes accuracy and reliability of the flowmeter. The experimental results verify that the flow meter is running well and achieves the overall performance goals of the plan.
Abstract: Based on the building of non-stationary road surface excitation mode, a study on the active suspension control under non-stationary running condition was conducted using control, state feedback control strategy for linear systems with time-domain hard constraints was propose. The proposed approach was applied to design active suspension systems on the basis of a two-degree-of-freedom quarter car mode, Simulation results show that the proposed constrained controller can achieve a promising improvement on ride comfort, while keeping dynamic suspension deflections, dynamic tire loads and control forces within given bounds, even non-stationary running.
Abstract: Enterprise Information, especially in the manufacturing process, material information management is a key technology. If some companies or individuals need to communicate or exchange the material information between them and they use incompatible systems, what style of data file will be chosen to exchange? Converting the data to XML can greatly reduce this complexity and create data that can be read by many different types of applications. This paper describes basic principle about XML(Extensible Markup Language) and its security, then analyzes an application of its security.
Abstract: Based on the principle of virtual prototype reality design and combined with the desired improvement of the user individuation in current product development. The system structure model of virtual prototype reality design of numerical control machine for Users is proposed. The main contents of the virtual prototype reality design system support environment in this model are discussed. The key technique of design process realization is provided.
Abstract: Based on VB.NET and ArcEngine, this paper aims at achieving the conversion of ArcGIS raster data to FLAC3D hexahedral grid data. On the analysis of the formats of ArcGIS raster data and FLAC3D hexahedral grid data, a conversion program is prepared and the former is converted to the latter, at last an application example is given. The result shows that this method can not only achieve three-dimensional geological model quickly but also simulate the real terrain. Thus providing a new method for three-dimensional geological modeling and the pretreatment of FLAC3D is simplified.
Abstract: With some increase in capacity, load and runtime, running safety of geotechnical centrifuge becomes more and more grim. General layout and structure of geotechnical centrifuge are introduced. Main fault and fault components of geotechnical centrifuge are analyzed. A new distributed equipment condition monitoring and fault diagnosis network system based on RS485 field bus and industrial Ethernet is designed. Key technologies of this system are researched. Real-time signals of vibration, temperature and strain can be synchronously collected and processed. The application of this system can provide a reliable basis for running safety and maintenance timely of centrifuge.
Abstract: This paper presents a two-stage DC-DC converter for electric vehicles that controlled by using a digital MCU with a lag algorithm. Because the fuel vehicle causes many environmental issues, the electric vehicle becomes a new tendency in vehicle fields. The voltage of power battery is very high and can’t charge for lead-acid battery directly, so DC-DC converter is an essential device. In order to absorb the advantage of digital converter and meet the requirement of widely range input voltage, a digital DC-DC converters for electric vehicle is proposed. The BUCK and half bridge topology was analysis in detail and chosen for the DC-DC converter. A digital DC-DC converter system which includes the hardware and software was designed. The sample circuit, driven circuit and how to make the power transformer is described in detail in hardware design. The software mainly consist the voltage regulate program and CAN communication program. A lag compensator was designed for the voltage regulate. A prototype was made and test in the charge of the lead-acid battery. The result shows the correctness of the topology selection and circuit design. It proved that the DC-DC converter can charge the lead-acid battery within working voltage of power battery and meet the specification basically.
Abstract: On the basis of analyzing folding method of the pantyhose available on market, this passage describes pantyhose automatic folding process in the automated packaging system, and focus on description of stereotyping board adding process. Then, it proposes a new adding stereotyping board method for the existing method, and describes the new method in detail. Finally, it compares the two methods, showing that the new method can solve the main problems in the former method, helping to improve the stability of automatic pantyhose packaging.
Abstract: In this paper, a new discretization method to obtain the sampled data representation of the nonlinear state delay control system is proposed. This discretization method is based on the matrix exponential computation. The mathematical structure of the new discretization scheme is explored. Then it is applied to obtain the discrete form of the nonlinear state delay continuous systems. The resulting time discretization method provides a finite dimensional representation for nonlinear control systems with state delay, thereby enabling the application of existing controller design techniques to such systems. The performance of the proposed discretization procedure is evaluated by means of the simulation study. In the simulation various sampling rates and time delay values are considered. The results demonstrate that the proposed discretization scheme can assure the system’s accuracy requirements.