Precision passive range measurement

Image feature analysis to determine object distance can provide precision performance if the optical point-spread function is highly sensitive to range. In the method presented here, a specially designed mask imparts a quarter-wave phase shift over part of the input aperture, thereby inducing an interference effect with maximum sensitivity. The resultant image can be compared with a conventional image through deconvolution and least-squares fitting in order to extract a precise range estimate. This method is quantitatively examined through computer modeling and laboratory testing and is broadly applicable to a wide range of optical wave bands.     

一种新的基于颜色统计特征的判别跟踪方法

针对目前目标跟踪的大部分判别算法注重跟踪效率而没有考虑尺度变化这一问题,提出了一个简单而鲁棒的基于颜色统计特征的判别跟踪方法。这种新的颜色统计特征具有一定的光照不变性,同时保持较强的判别能力。建立了跟踪过程的仿射运动模型,利用优化参数来解决尺寸及角度变化等问题。此外,为了进一步提高跟踪速度,采用低维的颜色统计特征描述目标外观,利用颜色统计特征训练贝叶斯分类器,将置信值最大的样本作为跟踪结果,并在线更新分类器。与现有跟踪器的大量综合性的对比实验表明,该判别跟踪方法在不同挑战因素下均有明显优势。     

Viability study for a new measurement system

Conclusion The suggested methodical principles for the viability study of an introduced measurement system showed that the introduction of the graphicoanalytical method of testing results in a yearly saving of more than 8000 rubles.Translated from Izmeritel'naya Tekhnika, No. 11, pp. 22–24, November, 1974.     

A fiberoptic pressure measurement system

Translated from Izmeritel'naya Tekhnika, No. 8, pp. 31–33, August, 1991.     

A solid-state relative humidity measurement system

The implementation of a solid-state capacitive relative humidity (RH) sensing system which employs a polymer as the moisture-sensitive material is discussed. The sensing mechanism is based on the fact that the dielectric permittivity of the insulating polymer, polyimide (PI), is linearly related to the ambient relative humidity. Therefore, the capacitance of a parallel-plate device using PI as the dielectric is a linear function of ambient RH (because PI does not swell during moisture absorption). Standard IC processing techniques are used to fabricate the PI-based integrated sensor capacitor. In order for such as sensor to be useful in the field, a voltage, current, or frequency output is desirable. A discrete capacitance-to-voltage converter circuit using this sensor capacitor has been constructed. The performance of this system is reported     

一种被动双阵航迹关联新方法

在被动系统中,多传感器多目标数据关联一直是一个难解决的问题.对静态数据关联多维指派"组合爆炸"问题,许多外学者提出了像最小距离法、最大似然算法等多种解决方法,但它们或正确相关率较低,或计算量较大.基于上述问题,提出了一种基于运动目标在时间上具有连续性的先验知识的新的航迹关联算法,该算法根据数据列之间发展态势的相似或相异程度来衡量航迹间接近的程度,使航迹关联问题突破了样本容量和典型分布这两条限制.仿真结果表明该算法计算量小,正确关联率高,具有较高的工程应用价值.     

A new MOSFET output conductance measurement technique

A new technique is presented for accurate measurement of the output conductance of a metal-oxide semiconductor field effect transistor (MOSFET). This technique allows the measurement of output conductance down to the sub μS region with an accuracy of better than 1%. Measurements in this range of output conductance are plagued by stray capacitances and noise. The new technique effectively combats these sources of error. The above-mentioned accuracy is maintained even when the susceptance due to the stray capacitance is as much as five times the conductance being measured     

A new filter-bank configuration for harmonic measurement

In this paper a new adaptive filter-bank structure suitable for the accurate harmonic measurement in power supply systems is presented. This adaptive measurement technique is based on the resonator-in-a-loop filter-bank structure and includes a new modified Gauss-Newton gradient algorithm. Using this filter-bank structure and a least-squared-error approximation method, simulation results are presented to establish the performance of the technique. The effects of time-varying fundamental frequency are also investigated using this filter-bank structure. Simulation results show that the fundamental frequency can be tracked with very small error. The technique is also successfully applied to a measured voltage signal sampled from the mains to demonstrate performance     

A transmission replica system for strain measurement

A low cost, rapid replica method has been developed to monitor the whole strain field near for example, welds, cracks and other sharp stress raisers. The technique uses transparent replicas that can be combined in several different ways to produce optical interference patterns representing the strain information. Several examples of the use of the technique are described.     

一种精密电容测试系统设计

该文介绍一种基于自动平衡电桥的精密电容测试系统设计方法,通过对激励信号与自动平衡电桥输出信号进行鉴相分析,给出被测电容值的计算方法。为使鉴相器处于最佳工作点,得到精度更高的电容值测量结果,系统对自动平衡电桥输出信号进行反馈,并根据反馈结果,结合标准电阻选择与程控放大器对信号进行调理。最后,在1 MHz的测试频率下对系统的电容测试精度进行验证,得出设计的电容测试系统具有较高的测试精度。     

A digital-signal-processor-based measurement system for on-linefault detection

This paper deals with the design, construction, and setting up of a measurement apparatus, based on an architecture using two parallel digital signal processors (DSP's), for on-line fault detection in electric and electronic devices. In the proposed architecture, the first DSP monitors a device output on-line in order to detect faults, whereas the second DSP estimates and updates the system-model parameters in real-time in order to track their eventual drifts. The problems which arose when the proposed apparatus was applied to a single-phase inverter are discussed, and some of the experimental results obtained in fault and nonfault conditions are reported     

A new type of grounding resistance measurement method

This paper discusses the measuring methods of grounding resistance. A new measuring method, which uses a higher order spectrum, is suggested. Compared with a power spectrum-based method, the new method can reduce the effect at Gaussian noise, and therefore can measure the grounding resistance more accurately. Simulation and experimental results demonstrate the effectiveness of the new method     

A new DSP method for group delay measurement

After a review of methods available for group delay measurement and their primary errors, a digital signal processing (DSP) method with excellent accuracy is proposed. The method is described, and a comparison is made with other methods. An example using the new method is given. When compared with the methods available, the new method does not involve compromises of the frequency intervals, and it eliminates the defects caused by the assumption of linearity of phase-frequency characteristics, the calculation of the phase-frequency characteristics, and the evaluation of the difference quotient, whose measurement accuracy depends only on the hardware and software used for measurement. It has the advantages of high precision and forthright computation     

一种测定润滑油总碱值的新技术

润滑油氧化变质是一个在所难免的问题，氧化致使润滑油的性能下降，进而导致设备故障。为防止润滑油过度使用，人们通常通过测定总碱值以了解润滑油中和酸性物质的能力。测定润滑油的总碱值的标准方法的化学试剂毒性较大，且滴定终点不易判断。这里介绍了一种新的测定技术一循环伏安法。研究表明，具有测定结果，准确、自动化程度高、操作简单、测定时间短等优点，适合进行现场润滑油测定。     

A new cryogenic memory system

The recently developed "current stretch" technique, a low temperature integration and amplification of sense signals, offers new freedom in the design of cryogenic memory cells. This scheme makes the sense voltage independent of cell switching speed and gives a good signal-to-noise ratio. A memory system using a double hole tin film storage cell driven by cryotron trees is described. Current stretch sensing is done through the trees so that no sense line is required. The cell operating range, which can be made arbitrarily large, has been set at 40 percent in the present study. Cells have been tested at densities of 10³bit/in²and switching speeds of 100 ns. Densities of 10⁴bit/in²appear feasible with existing fabrication techniques. In sizes of 10⁸cells or above, this memory system appears cheaper than any known room temperature technique of equal speed.     

Estimating particle concentration using passive ultrasonic measurement of impact vibrations

A method of obtaining particle size and concentration information, from ultrasonic transducer measurements of particle-wall interactions in a particle laden fluid, is presented. A mathematical model of the flexural vibrations of the vessel wall due to the particle impact is constructed. The key component of this model is the derivation of an analytic expression for the impact force amplitude. An analytic expression for the power spectrum is then obtained that shows its explicit dependency on the system parameters. This spectrum is then integrated over a specific frequency range and a comparison with experimental results is reported.     

A new current measurement method in resistance spot welding

A method of measuring the high current in resistance welding processes is investigated. A measuring unit is developed by using a strain gage attached on the outer surface of a steel ring. The steel ring is placed around a section of the secondary loop of the welding machine and is deformed by electromagnetic forces induced by the high welding current. The circumferential constituent of the ring deformation is then used to obtain a signal voltage proportional to the secondary welding current. The strain gage signal of ring deformation is enough to determine the welding current in resistance spot welding, especially when direct current is used for the welding