[雙語翻譯]超聲波測距外文翻譯--低成本超聲波測距系統(tǒng)的設計考慮和性能

1、3000 英文單詞， 英文單詞，1.6 萬英文字符，中文 萬英文字符，中文 5050 字文獻出處： 文獻出處：Zivkovic D S , Markovic B R , Rakic D , et al. Design considerations and performance of low-cost ultrasonic ranging system[C]// Positioning Navigation & Communic

2、ation. IEEE, 2013.Design Considerations and Performance of Low-Cost Ultrasonic Ranging SystemDragan S. Zivkovic, Bogdan R. Markovic, Dejan Rakic, Srdjan TadicAbstractNumerous systems for reliable, low-cost, indoor, ultra

3、sonic sensing have been demonstrated during the past few decades. Existing solutions span very low-cost transducers to high-grade equipment. This paper presents design details of a low-cost, single-tone, ranging system.

4、A set of experimental results is included in order to evaluate consistency between ranging results obtained from receivers with various architectures. The effects of channel equalization and signal pre- coding evaluated

5、show how these systems can deal with realistic reflectors.Index Terms— ultrasonic transducers, Cramer-Rao bounds, time of arrival estimation, indoor environments, CFAR, Tomlinson-Harashima pre-coderI. INTRODUCTIONRANGING

6、 is an essential element in many robotics, industrial, and ambient-intelligence applications. Ultrasonic sensing is a potential solution for reliable and low- cost indoor localization and ranging. In the experiments desc

7、ribed within this paper, ultrasonic transducers, acting as both emitters and receivers, were used to locate reflectors based on the Time-of-Flight (ToF) of sound waves. The performance of ultrasonic distance measurement

8、depends on employed signal bandwidth, which directly limits the amount of available information. The presented system uses low-cost, narrow-band, piezoelectric transducers (PZT). A focus of the work was to consider rangi

9、ng consistency and investigate the benefit of bandwidth extension by channel equalization and a constant-false alarm rate (CFAR) [1] based detection of quality of ranging measurements. The system suggested presents core

10、technology for more complex, sensor-array based localization or bearing estimation [2][3]. Such systems ordinarily use Direct Sequence Code Division Multiple Access (DS-CDMA) to manage the multiple access of a number of

11、transducers. This was stimulus to additionally explore the impact of Pseudo-random Noise (PN) signaling to the system[4].A. OrganizationThe paper's organization is as follows: Section II briefly introduces the ultras

12、onic sensing problem and related prior work. Section III presents design details of the developed system. Experimental results are described in Section IV. Section V gives an overview of processing hardware and related p

13、ractical considerations. The conclusions are given in Section VI.II. ULTRASONIC SENSING AND RELATED WORKThe ultrasonic sensor will measure distance by emitting a sound wave and then “l(fā)istening“ for a set period of time,

14、allowing for the return of echoes bouncing off the target, before re-transmitting. Due to the phenomenon called ringing– a continued vibration of the transducer after its excitation pulse – the sensor cannot reliably mea

15、sure within a so-called “dead zone” in its proximity. The accuracy of measurement depends on the accuracy of the speed of sound used in calculation. The speed of sound (c) can be derived assignal bandwidth”. The transmit

16、ted signal is a short Kasami code modulated by the carrier at 40 kHz. The transducers’ 6dB beam angle is 80 degrees (Fig. 1). The receiver sampling rate was 100 kHz. 8000 samples (80ms) were used in order to analyze echo

17、 and detect surrounding obstacles. Distance is estimated by the Round Trip Time of Flight (RT-ToF). This limits setup for measuring distances up to 12.5m, due to necessary guard intervals between consecutive pulses. The

18、matching maximum signal rate was 12.5Hz.Fig.1. Nominal values of a transmitter sound pressure levelRanging was done using 1 kHz or 4 kHz pulses. As a sampling frequency of 100 KSPS was applied, the receiver reduced proce

19、ssing burden and matched the same effective sampling frequency, as it was constructed with two different down-sampling ratios (1 kHz - 20, 4 kHz – 5). As RT-ToF ranging is used, the resulting system resolution, calculate

20、d according to (2), of a 1 kHz system is 33mm, while a 4 kHz system should be capable of detecting obstacles of 8.25mm (Fig. 2.). Various ToF methods are presented in [7][8]. The impulse response of the transducer sampl