Double threshold ultrasonic distance measurement technique and its application

et al. 2020

Sensors

Aiming at the problems of substantial pressure loss, small range ratio and contact measurement in traditional gas flowmeters, this paper designs a new type of data-filtering ultrasonic gas flowmeter. The flowmeter is composed of hardware circuits such as STM32F407 (ARM Cortex 32-bit microcontroller) main control chip and high-precision timing chip TDC-GP22 (time to digital converter). The software uses a new data-filtering algorithm combining Kalman filtering algorithm and arithmetic average algorithm to improve the measurement accuracy of ultrasonic gas flowmeter. Through experimental comparison, we find that the filtering algorithm effectively reduces the measurement error of the system. Within the flow range of 0.025–4 m3/h, the maximum relative error of the system measurement is 2.7404%, which meets the national standard for the measurement error of the 1.5-level instruments. Moreover, it reduces the zero-drift to about one half of the original, which significantly improves the stability of the system. The gas flowmeter has the characteristics of high accuracy, good stability, low power consumption, and the overall performance is significantly improved.

Section: Methods Of Time-difference Measurementmentioning

confidence: 99%

Section: Principle Of Time Difference Measurementmentioning

confidence: 99%

Design of a High Precision Ultrasonic Gas Flowmeter

Chen

Zhang

et al. 2020

Sensors

“…Where, t u_i and t d_i are the times corresponding to the i-th synthetic peak point in Figure 10. After, gas velocity can be calculated by substituting t u and t d into Equation (3). Figure 11 presents the complete flow chart of the UDCSP method to process the ultrasonic received signals.…”

Section: The Ultrasonic Signal Dbscan Clustering Synthetic Peak Methodsmentioning

confidence: 99%

A new method for processing ultrasonic gas flowmeter signal in wet gas

IET Science Measure & Tech

Zheng

Mei

et al. 2020

Gas velocity as an important characteristic parameter of wet gas has become a very active research issue in engineering field. Among many gas velocity measurement techniques, the ultrasonic flowmeter technique is more suitable for actual working conditions. However, the traditional signal processing methods of ultrasonic flowmeter are only proposed for single‐phase gas. In wet gas, the ultrasonic signals fluctuate greatly, are easily distorted and even lost, so the single‐phase ultrasonic signal processing methods are not applicable. Therefore, a new ultrasonic signal DBSCAN clustering synthetic peak method is proposed to solve the above problems. To verify the feasibility of this new proposed method, three real flow experiments are carried out on horizontal pipe at ambient temperature and pressure. Additionally, comparing the gas velocity results using ultrasonic signal double threshold method and ultrasonic empirical model method for single‐phase gas and the new proposed method for wet gas, it is shown that the measurement results using new proposed method accord with the theoretical law and can accurately measure the gas velocity. Furthermore, the three real flow experimental results show that the repeatability of gas velocity in wet gas by the new proposed method is mostly <0.5%.

“…The ultrasonic velocity is easily affected by environmental temperature. If the environmental temperature is unknown, a non-ignorable measurement error will occur in practical applications [16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

A New Positioning Method Based on Multiple Ultrasonic Sensors for Autonomous Mobile Robot

Shen

Jiang

et al. 2019

Sensors

This work proposes a new positioning method based on multiple ultrasonic sensors for the autonomous mobile robot. Unlike the conventional ultrasonic positioning methods, this new method can realize higher accuracy ultrasonic positioning without additional temperature information. Three ultrasonic sensors are used for positioning. A generalized measurement model is established for general sensor configuration. A simplified measurement model, which considers the computational complexity, is also established for linear/simplified sensor configuration. Three time-of-flight signals are obtained from the three ultrasonic sensors. The coordinates of the target are calculated by the ratios of time-of-flights. Positioning experiments were carried out to verify the feasibility and effectiveness of the proposed method. Experimental results show that the new ultrasonic positioning method is effective, both the two established models can implement positioning successfully, and the positioning accuracy is satisfactory. Compared with the conventional ultrasonic positioning method with the default ultrasonic velocity, the positioning accuracy is greatly improved by the proposed method. Compared with the ultrasonic positioning method with additional temperature compensation, the results obtained by the proposed method are comparable.Huang and Young presented an accurate ultrasonic distance measurement system which had a self-temperature compensation with the environmental average temperature in space [25]. Although these methods can improve the positioning performance, they need to introduce additional temperature sensors and a calibration process, which make the positioning system more complex.This work aims to propose a new positioning method based on multiple ultrasonic sensors (three sensors in this work). The new method can implement higher accuracy ultrasonic positioning without additional temperature information or calibration process. The coordinates of the target are calculated according to the ratios of three time-of-flights measured by the three ultrasonic sensors, which means the influence of environmental temperature on positioning is avoided. Different from the previous/conventional methods using time-of-flights directly for positioning [12,[20][21][22][23][24][25][26][27], this work features in a novel idea which uses the ratios of time-of-flights to realize ultrasonic positioning and hence to improve the positioning accuracy. Figure 1 shows the basic measurement principle of ultrasonic ranging. New Ultrasonic Positioning Method