金属三维打印能够实现复杂功能零件直接制造与净近成型,具有广阔的应用前景和重要的研究价值.在高精度金属三维打印领域目前以选择性激光烧结(SLS)工艺为主,但由于选择性激光烧结工艺的设备成本高、模型成型时间长、金属粉末材料选择范围窄等原因,限制了其应用范围.本文提出一种"基于数字微喷与UV光固化相结合的金属粉末三维打印"实现方法,开发出一套完整的硬件平台与软件系统,并进行了相关的实验,验证了工艺的可行性和开发系统的可靠性.该方法为金属三维打印提供了新的实现方法,具有较高的研究价值和意义.

将微粒群优化(PSO)算法应用于3D打印喷头温度检测系统的非线性特性校正.在温度传感器特性无法准确获取的情况下,给出了基于PSO算法和逆模型实现非线性特性的线性化校正的一般实现思路和步骤.首先对采集到的样本进行特征分析,提炼出温度传感器非线性特性的逆模型,再利用PSO算法对逆模型中未知参数进行优化求解,从而实现了3D打印喷头温度非线性特性的线性化校正.最后,对3D打印喷头温度检测系统进行了实验研究,对比了逆模型的PSO参数优化求解和Matlab曲线拟合求解的实验结果,验证了本文基于PSO的喷头温度非线性特性的线性化校正方法的可行性,并可以扩展到一般非线性传感器的线性化校正应用中.

The phase inductance character of permanent magnet synchronous motor (PMSM) is closely related to its saliency, which has significantly influence on the position estimation using high frequency signal injection at low speed. In this paper, the relationship between phase inductance harmonics and position estimation error is discussed with qualitative and quantitative analysis, which is helpful for improving position estimation accuracy and supervising PMSM design. The validity of the analysis is verified by simulation and experiment tests.

无刷直流电动机直接转矩控制系统中定义开关管全关对应的电压矢量为零矢量.分析了全关条件下无刷直流电动机的电压电流变化规律,指出由于电感电流的连续性以及续流二极管的存在,全关条件下作用在电机上的电压矢量实际为对应导通条件下的反矢量,根据全关条件下电机电压电流的变化规律,提出了适用于两相导通无刷直流电动机直接转矩控制系统的新的零矢量.仿真结果验证了理论分析的正确性,以及引入新定义的零矢量对降低转矩脉动的有效性.

Universal serial bus (USB),simple in structure,easy to expand,suitable for wide-ranging data transmission,fast to process has been widely used.Based on Digital Signal Processor (DSP) chip TMS320F28335,the USB communication system module of hardware circuit and software program design is presented in this paper.

The double closed loop structure of stator flux linkage and torque is used to realize direct control of motor torque in traditional direct torque control of permanent magnet synchronous motor. Because flux amplitude is kept as constant,dynamic performance of the motor is not only restricted,but also reactive current is increased. When reactive current is increased,motor power factor is reduced and system loss is increased. From the points of perspective of optimal control of the torque and reactive current,a novel direct torque control method is presented in this paper. Voltage vectors are merely selected according to the requirement of the torque control in the period of control. In the control process, stator flux amplitude can be dynamically adjusted and rotor position is less demanded. So dynamic performance of the motor and power factor are significantly improved. The correctness and feasibility of the proposed method are verified by the simulation results.

The paper investigates the problem of robust stabilization for a class of nonlinear time-delay systems with polytopic uncertainties.Based on a parameter-dependent Lyapunov functional,state feedback controllers are designed such that the closed-loop system is robustly asymptotically stable for all admissible uncertainties.The main results were presented by linear matrix inequality.A desired state feedback controller can be constructed by solving a set of linear matrix inequalities.The conservatism is smaller because the result is delay-dependent.

A improving scheme of realizing the precision and the stability of the multi-sensor electron balance is presented.Considering the conditions of weighing system,the forces of sensors are analyzed and the system structure is improved to enhance the system stability by the research of the factors which affect the weighting system precision.The causes of nonlinear of the multi-sensor system are discussed.According to the sensor input-output characteristic curve,linear of multi-sensor is processed by the dynamic compensative circuit.The system is optimized by the means of hardware.System precision and stability is greatly improved.

This paper considers the problem of stabilization of neutral delay systems via output feedback controllers, aims to design such a dynamic output feedback controller that the resulting closed-loop system is asymptotically stable, obtains a sufficient condition for the solvability of the problem with the linear matrix inequality (LMI) approach,and gives an explicit expression of desired dynamic output feedback controllers when the given LMIs are feasible. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed method, and at the same time, its simulated curve is given.

The problem builds database librarise by SQL Server 2000 , and manage medicine in/out warehouse and finance in web pages form , by ODBC link database. It uses Recordset object of ADO to build data source nonius. This system can make vaniety hands of user share and architecture same database. It realizes data sharing and refresh. The type is a kind of medicine management system based on client/servers.

用硬件描述语言VHDL对SR电动机比例因子自调整模糊控制器进行了数字设计,并用FPGA加以实现,制成了高可靠性的单片SRD控制电路.实验表明:用VHDL设计的SRD模糊控制器不仅可靠性高,而且还支持众多的硬件模型,具有较强的通用性.

论述某邮局悬挂分拣机分拣系统的设计与实现,以及PLC,InTouch组态软件的运用.

研究不确定离散线性系统的保成本控制问题, 目的是设计状态反馈控制律,使时乘二次成本函数有一个确定的上界.同时还给出了期望状态反馈控制律的存在条件及其解析表达式.