Proc. SPIE. 9446, Ninth International Symposium on Precision Engineering Measurement and Instrumentation
KEYWORDS: Phase shifting, Sensors, Error analysis, Field programmable gate arrays, Telecommunications, Signal processing, Signal generators, Dynamical systems, Information operations, Voltage controlled current source
The mechanical phase shifting method is often used to evaluate the accuracy of transmission error (TE) testing system, but the application scope of the mechanical phase shifting method is limited. This paper designed a new type of TE signal generator. Firstly, based on the principle analysis of the mechanical phase shifting method, the relationship between angle error from mechanical phase shifting and pulse signal of sensor is established, and then according to the TE’s synthesis formula we can obtained two displacement sensor signals which are used to replace real mechanical phase forming a special TE signal generator. The signal generator is composed of FPGA and ARM. The TE detection system is used to test the signal generator, after analysis, the error of the TE signal generator is 0.1%, which shows that the TE signal generator can be used to assess accuracy of TE system instead of the mechanical phase shifting method.
To realize the design of dynamic acquisition system for real-time detection of transmission chain error is very important to improve the machining accuracy of machine tool. In this paper, the USB controller and FPGA is used for hardware platform design, combined with LabVIEW to design user applications, NI-VISA is taken for develop USB drivers, and ultimately achieve the dynamic acquisition system design of transmission error
According to the Lambert-Bee law, we can see that the photic absorption coefficient is related to the matter's
concentration, the distance of the light through the absorption medium and the transmitted light intensity. The paper just
according to the physical phenomena and the theory make the reflex energy relate to the concentration testing of the
electrolyte, at the same time the electrolyte's concentration is related to the capacity of lead-acid battery on a
corresponding function relation, so we can know the capacity state of the lead-acid battery according to the measurement
on the electrolyte's concentration. According to the experiment and research the author deeply discussed how the
temperature change affects the capacity of lead-acid battery and the concentration's changing relation, according to the
analyses of the thermo-optic effect, we made a new reflecting fiber sensor based on the comparative temperature testing
theory and absorption which can eliminate the temperature effect on the tested signal namely the output signal just
related to the concentration, so really reflects the change of the capacity of the lead-acid battery when it is in the charge
and discharge process. The results of the experiment and theory analyses show that this method is easy to realize the online
testing of the capacity of lead-acid battery. This sensor has many merits such as precise measurement, sensitive
reaction, long-life use etc. It can be widely used in the electric capacity testing of the automobile lead-acid battery, the
electric capacity testing of the industry lead-acid battery, liquor's concentration testing and salinity testing of the sea and
have a bright future.
In a biological system which contains microbial bacterium liquid, we set a fiber attenuation measuring system. The
change of the biomass concentration will affect the change of the light absorption and light scattering, and then change
the receiving power. The paper bases on this physical phenomena and theory, makes the receiving power relate to the
biomass' concentration testing and set up a new method to measure the biomass concentration. The paper describes the
sensor's composing theory, the light path analyses and its theory explanation, at the same time deeply discusses that how
the biomass changes in the near infrared circumstance. The experiment results and analyses show that this method is
linear well to measure the microbial liquid concentration, it have many merits such as precise online testing, high
sensitivity and long life use etc. The sensor's design theory and method is meaningful to be used on the preparation,
making alcohol, microanalysis, biochemistry and environment protecting etc. It is a practical new style biomass
concentration sensor and has a bright future.
At present years, fuzzy control technique has been applied and extended on engineering control. The paper adopts 89C52
single chip (SCM) as the hardware platform and applies fuzzy control strategy and algorithm to realize the design of the
fuzzy controller. The controller composed to be a closed-loop real-time control system by computer, A/D, D/A, sensor,
executed motor and controlled object. The structure is a double closed-loop control structure. The system is a double
closed-loop control system. Inner loop adopts an analog current controller and outer loop adopts a digital controller. The
system applied fuzzy control strategy and algorithm. The controller takes Volts D.C. signal, pulse signal, analog
feedback current signal as its input and on-off magnetism team motor as its control structure. That is to say, the
controller is divided into basic fuzzy control and warp integral control, increases proportional integral, decreases the
fluctuation near the zero in order to improve the precision of controller.
The paper introduces a variable frequency power on permanent magnetism step rotation pulse-width modulation. It consists rectifier filter, computer control circuit and inverter. According to the equal-acreage principle, the computed width data of the chopped pulse of the frequency conversing power gets two-phase data in 60°, and the output wave of this mode make the motor magnetism constant, while each magnetism directions on two sides of each chopped wave keep invariable, so the magnetism is regarded as step rotating in microcosmic. If theoretic output plus is 100% standard pulse-width modulated sine wave, the harmonic distortion can be less than 5%. When they are working, the wave is double polar in two-third cycle and single polar in one-third cycle in order to make total power wastage reduce by one-third. If depress the frequency and keep the pulse width, output voltage whose fall is in proportion to the frequency's fall can be got, so as to realize variable frequency, variable voltage in order to certain the output of the unsaturated motor magnetic circuit and constant torque. The power can be widely applied in the fields of machinery, metallurgy, chemical industry, light industry, etc.