Development of Data Acquisition and Processing System Based on DSP and USB 2.0

The data acquisition and processing system are proceeding towards faster, more powerful, easier to use and more cost effectiveness. This paper discuss the design of the high speed and convenient data acquisition and processing system based on DSP and USB 2.0, and expatiates the principle and method of the virtual instruments system in detail. The system employs an ADS8346 to sample the six channel signals simultaneously with a resolution of 16-bit.It utilizes EZ-USB FX2 as the USB2.0 interface, which can achieve the high speed communication between the host and the system. It uses TMS320VC33 (dsp) as the core chip, which can accomplish the function of the main control and real-time digital signal processing. The system enhances the virtual instruments' advantage more by the combination between software and hardware.     

Design of compatible processing and analyzing system for nuclear signals

To on line detect, store and process nuclear signals with multiple forms and multiple frequencies, a compatible processing and analyzing system for nuclear signals based on ultrahigh speed data acquisition card was constructed. When the source signal is at pulse form, the system records signal with the mode of time digital converting. When source signal is at continuous form, the system records signal with the mode of analog digital converting. The processing procedures and algorithms were designed for various signal forms. The results for nuclear random process such as correlation function and power spectrum were effectively obtained.     

Application of DMA in Realtime Image Processing

Direct memory access(DMA)is an important technology used for fast speed data transfer in data signal processor(DSP). DMA is able to move data block independent of CPU, and this capability meets real time image processing. TMS320C6201 DSP is taken as an example, and DMA controller characteristic is introduced. According to DMA application in realtime image processing, the specific control ways and realization steps are given out. The research result shows that the flexible control DMA can not only raise image data transfer efficiency but also improve DSP speed.     

PCI Bus Card and Its Applications in the Virtual Instrument

This paper analyses the PCI bus features, and introduces several developing tolls and the techniques, including PCI controller IC, driver development software and the key points of designing PCI cards with the main focus on IC S5933 and driver development software WinDriver. An example in the virtual instrument-a random signal generator, consisting of PCI card and software, is also given. DDS is realized by software, through the high transfer speed of PCI bus. The signal generator can produce sin, noise, frequency sweep and others complex waves. It can be used to adjust the wave, frequency, amplitude, phase and precision conveniently and accurately.     

Method of Measuring Rotational Speed for a High-speed Rotator Dynamic-balancing Testing System Based on DSP

The device of testing rotational speed is very important to dynamic-balancing testing system.Requirements for the device of testing rotational speed include: high-accuracy,stabilization,credibility,and shorter testing time.To the development of high-speed rotor dynamic-balancing testing system based on DSP(digital signal processing),the way of picking-up rotator reference signal,testing rotator speed based on DSP and the design of software are introduced.This new way of testing rotational speed in high-speed rotor dynamic-balancing testing system based on DSP is accurate,simple,convenient,the range of rotational speed which can test is broad,and the new way is very suitable to pick-up the amplitude and phase of vibration caused by unbalanced amount.     

High speed, high precision digital phase sensitive detector design for electrical impedance tomography

Electrical impedance tomography (EIT) system must have the properties of high precision and speed, thus the digital phase sensitive detector (DPSD) based on the field programmable gate array(FPGA) is developed for data collection of EIT. Based on the principle of DPSD, the relationship between signal to noise ratio (SNR) and sample resolution as well as total number of samples is deduced. An implementation scheme of this system and a method of designing analog to digital converter (ADC) clock based on direct digital synthesis (DDS) technology are provided. The system adopts high speed multi channel ADC and low jitter clock conditioner for ADC. Real time DPSD is implemented with FPGA. The experiments show that the measurement accuracy reaches 0.03% and the SNR reaches 85 dB. The agar phantom experiments prove that the performance of the DPSD meet the designing requirement for EIT.     

Sampling Technique of ECG Signal in Windows98

A method of real time sampling and data processing of ECG signal in Windows98 is introduced in this article. It makes the data collecting and processing easy by driving the A/D transforming card with the Vxd programmed with VtoolsD and VC++, drawing the curve of ECG on memory DC, and utilizing the virtual memory technique to realize the data storing.     

Development of Virtual Sweep Signal Source

A new kind of virtual sweep signal source which can be used to output specific sweep signal according to(users') configuration and can be widely applied to frequency characteristics measurement in the field of mechanics,electrics and electronics,is developed by using Dot Net software engineering technique,C/S architecture and general data acquisition platform.The virtual instruments not only make up the intrinsic defect of traditional instruments based on hardware components in high performance,remote control and data processing,but also indicate the powerful life and nice future of virtual instrument technologies.     

Application on Extracting Feature in State Monitoring and Fault Diagnosis

With the development and application of information and internet and virtual instrument technology ,the virtual globular company based on internet arises .To study remote state monitoring, remote fault detection and diagnosis about large scale, complicated and integrative equipment become very important. In the whole fault diagnosis system , the detecting ,data acquisition is original ,processing; transform and extracting features with the signal detected is a key factor. The theories and methods used in mechanical fault diagnosis is stated. The application of signal process and its feature extracting methods is introduced which are time domain, frequency domain and time frequency domain analysis, in state monitoring and fault diagnosis with its signal analysis. The processing method of random time variant special signal is given also.     

Study on the Difference Phase Degree Division Displacement Transducer

Pointing out the shortages of the traditional bar thread displacement transducer, brings forward new thought of designing difference phase degree division displacement transducer, which transforms the problem of measuring displacement directly in angle into the problem of measuring the difference between the phases of two signals which have the same frequency and then gets the displacement in angle indirectly. The theories on designing the phase difference calculation displacement transducer and correlation displacement transducer is suggested. Because the difference phase degree division displacement transducer, supported by the computer technology and the signal processing technology, adapts to the development of instrument's fictionzing and intelligentizings, it is an advanced technology.     

Digital Filtering with Zero Phase Error

Aiming at the problem of phase error caused by normal filters in signal processing , summarizes the important meaning of digital filtering with zero phase error. Puts forward RRF Filtering which is a new way to realize digital filtering with zero phase error through reversing the time serials of the signal. Another way to realize digital filtering with zero phase error is suggested through reversing the time serials of normal filter. Testifies the way to realize digital filtering with zero phase error. Points out how to design the digital filter with zero phase frequency peculiarity. Solves the problem of phase error in DSP.     

牧草观测自动化技术研究与系统设计

针对内蒙古自治区生态观测需求,特别是草地生态系统观测需求,选取牧草观测为研究内容,提出基于嵌入式技术和并行计算技术的实时远程可控可视的牧草观测自动化技术思路。采用特征像素图像识别方法,实现牧草覆盖度的自动测量、牧草的发育期图像自动识别。利用摄影测量技术结合图像处理技术获得像高转物高变换算法,实现层高与株高的自动测量。结合现代电子技术以及DSP技术、图像处理技术设计了牧草自动观测智能传感器,传感器在观测前端完成图像采集、处理与模式识别后,再将处理后的结果通过网络传向服务器端,可通过智能手机或PC访问服务器远程查看观测数据,实现牧草覆盖度、层（株）高以及牧草生长期的自动观测。测试结果表明,图像处理与实测覆盖度数值显著相关检验R_0.05>0.90,与实测株高数值显著相关检验R_0.05>0.85。相对于在后端PC系统进行图像处理,不但可以提高观测系统的数据运算处理速度,而且鲁棒性好,同时能够大大减轻数据传输压力,适合对体积、功耗、工作环境及稳定性要求极高的场合。     

Embedded Intellingent Dynamic Balance Testing System and Its Digital Filter Designing

A lot of information needs processing in time in dynamic balance testing, but the current intelligent dynamic balance instruments and the controlling box of dynamic balance machines made up ofsinglemicrocontroller do not meet the request.A method isgioen that the DSP-Microcontroller will be useddiredtlyinthe system of the intelligent dynamic balance instrumentby using embedded design technique. A principal and subordinate control system compose of DSP and microcontroller. The Microcontroller the system as a principal controller and the DSP implements digital filtering and FFT in dynamic balanc by means of its fast operation. The system develoyed according tothe method can do more analysisin time areaand frequency area.     

Virtual FFT Spectrum Analyzer Based on DSP Technology

Virtual Instrument has become an important direction of instrument development, now it has been widely used in many fields. FFT analysis is a widely used method in mechanical engineering, fault detection and many other fields. However, the traditional FFT analyzer is expensive and is not easy to upgraded. The birth of virtual FFT Spectrum Analyzer gets rid of the limit of traditional FFT analyzer, and paves the way for the application of FFT analyzer. The uses of DSP technology make the future broadened of Virtual Instrument. This article ,based on the deep study of DSP system, designs a virtual FFT Spectrum analyzer based on DSP technology. The design is new and of great practicality, which indicates the important role of Virtual Instrument in the development of instruments.     

Methods of Software Optimization in Real-time Tracking System Based on DSP

The DSP(digital signal processor) of TMS320C6000 series,has a special structure VLIW(very long instruc-tion word),which makes the functions of hardware depend on the efficiency of software.Therefore,when DSPs of thisseries are used to design a real-time tracking system,the executing efficiency of software will directly affect the real-timespeciality of the system.Several methods of optimizing software based on C6000 DSPs are researched,including choo-sing compiler options,use of DS Pkey words and intrinsics,data packed and software pipelining.Optimizing software ofthe whole system by using these methods,primely can solve the problem of bad real-time in processing.Consequently,the stability of the whole system is improved.     

Design of nondestructive examination system for bridge cables surface defect

Aiming at the drawbacks of the current detecting methods, a nondestructive examination system design for bridge cables based on high speed digital signal processors chip DM642 is presented, and the hardware platform of the system is built. This examination system mainly consists of four parts: the image defaults acquisition part, DM642 hardware platform, creeping part and defaults locating equipment. The designed system is tested on the hardware platform based on digital image processing algorithm. The experimental results show that the detecting system has the advantages of high stability and reliability, real time, mass storage, and nondestructive examination, etc. This system uses high technology and has significant meaning on detecting the current bridge cables health, furthermore, this method can be used in other examination fields.     

电液驱动式变量施肥闭环控制系统研究

变量施肥技术是精准农业技术的重要组成部分。由于施肥机是通过液压马达驱动的,本文设计相应驱动方式下的基于单片机的控制器。该控制器通过串口RS232接收来自田间计算机的控制命令,进行解析处理后,生成相应的I/O口信号,经过驱动电路放大后控制执行元件动作。同时,控制器利用车速度传感器、排肥轴磁阻转速传感器通过采样获得排肥轴转速信息,反馈给控制器实现闭环控制。变量施肥试验表明,所设计的变量施肥控制器能满足变量作业的要求。     

ECG Signal Acquisition Instrument Based on USB 2.0

An electrocardiogram (ECG) is an essential way for diagnosing the heart disease, and the test theories and systems work well with the practice application, whereas, as new technologies and devices come forth one after another, it allow us to acquire the ECG data more conveniently, more accurately, more comprehensively. The authors discuss the design of ECG data acquisition system based on the USB 2.0 protocol, and expatiates the system principle in detail. The system employs two AD73360 to sample the standard 12-lead signal simultaneously, which has a resolution of 16-bit. They utilize EZ-USB FX-2 as the USB interface device, which can transfer the data conveniently and quickly, and also permit the configuration of multi-system controlled by just one host. Considering the DSP as a powerful tool in the field of digital signal processing, ADSP-2181 has been chosen.     

Flowmeter Based Virtual Instrument

The flowmeter based virtual instrument is a new test instrument, which has more advantages than the traditional flowmeter. This flowmeter is based on Qin's model. Apply to the flowrate measurement realm the virtual instrument technique. The design method has been introduced from hardware, software and panel, modelize the different flowrate measure way, with the virtual instrument's figural calculation and show to replace the traditional flowrate measurement, realize multi-threading long-distance flowrate measure easily.     

汽车转弯自动照明控制系统数据采集滤波方法

为了减少汽车转弯自动照明控制系统数据滤波处理中的延时,在滑动中值滤波方法基础上,提出了一种带补偿的限幅滑动中值滤波算法,通过补偿的方式跟随信号的变化趋势。该算法通过2个步骤完成滤波,先对数据进行带补偿方式的限幅处理,再进行滑动中值滤波处理。该算法综合了滑动中值滤波法的实时性以及限幅滤波法对偶然性干扰滤除的有效性,实现更准确的滤波。仿真与实测结果表明,与滑动中值滤波方法相比较,改进后的算法滤波能够实时地滤除数据中的干扰,处理时间可减少62%,滤波效果较好,且速度信号的数据滞后时间较短,实时性较高,满足系统设计要求。