Ultrasonicrangingsystemdesign超声测距系统设计大学毕业论文外文文献翻译及原文.docx

1、Ultrasonicrangingsystemdesign超声测距系统设计大学毕业论文外文文献翻译及原文 毕 业 设 计（论文）外 文 文 献 翻 译文献、资料中文题目：超声测距系统设计文献、资料英文题目：Ultrasonic ranging system design文献、资料来源：文献、资料发表（出版）日期：院 （部）： 专 业： 班 级： 姓 名： 学 号： 指导教师： 翻译日期： 2017.02.14Ultrasonic ranging system designPublication title: Sensor Review. Bradford: 1993.Vol. ABSTRACT

2、: Ultrasonic ranging technology has wide using worth in many fields, such as the industrial locale, vehicle navigation and sonar engineering. Now it has been used in level measurement, self-guided autonomous vehicles, fieldwork robots automotive navigation, air and underwater target detection, ident

3、ification, location and so on. So there is an important practicing meaning to learn the ranging theory and ways deeply. To improve the precision of the ultrasonic ranging system in hand, satisfy the request of the engineering personnel for the ranging precision, the bound and the usage, a portable u

4、ltrasonic ranging system based on the single chip processor was developed. Keywords: Ultrasound, Ranging System, Single Chip Processor 1. Introductive With the development of science and technology, the improvement of peoples standard of living, speeding up the development and construction of the ci

5、ty. Urban drainage system have greatly developed their situation is construction improving. However, due to historical reasons many unpredictable factors in the synthesis of her time, the city drainage system. In particular drainage system often lags behind urban construction. Therefore, there are o

6、ften good building excavation has been building facilities to upgrade the drainage system phenomenon. It brought to the city sewage, and it is clear to the city sewage and drainage culvert in the sewage treatment system. Comfort is very important to peoples lives. Mobile robots designed to clear the

7、 drainage culvert and the automatic control system Free sewage culvert clear guarantee robots, the robot is designed to clear the culvert sewage to the core. Control system is the core component of the development of ultrasonic range finder. Therefore, it is very important to design a good ultrasoni

8、c range finder.2. A principle of ultrasonic distance measurementThe application of AT89C51: SCM is a major piece of computer components are integrated into the chip micro-computer. It is a multi-interface and counting on the micro-controller integration, and intelligence products are widely used in

9、industrial automation. and MCS-51 microcontroller is a typical and representative. Microcontrollers are used in a multitude of commercial applications such as modems, motor-control systems, air conditioner control systems, automotive engine and among others. The high processing speed and enhanced pe

10、ripheral set of these microcontrollers make them suitable for such high-speed event-based applications. However, these critical application domains also require that these microcontrollers are highly reliable. The high reliability and low market risks can be ensured by a robust testing process and a

11、 proper tools environment for the validation of these microcontrollers both at the component and at the system level. Intel Plaform Engineering department developed an object-oriented multi-threaded test environment for the validation of its AT89C51 automotive microcontrollers. The goals of this env

12、ironment was not only to provide a robust testing environment for the AT89C51 automotive microcontrollers, but to develop an environment which can be easily extended and reused for the validation of several other future microcontrollers. The environment was developed in conjunction with Microsoft Fo

13、undation Classes (AT89C51). 1.1 Features * Compatible with MCS-51 Products * 2Kbytes of Reprogrammable Flash Memory Endurance: 1,000Write/Erase Cycles * 2.7V to 6V Operating Range * Fully Static operation: 0Hz to 24MHz * Two-level program memory lock * 128x8-bit internal RAM * 15programmable I/O lin

14、es * Two 16-bit timer/counters * Six interrupt sources *Programmable serial UART channel * Direct LED drive output * On-chip analog comparator * Low power idle and power down modes 1.2 Description The AT89C2051 is a low-voltage, high-performance CMOS 8-bit microcomputer with 2Kbytes of flash program

15、mable and erasable read only memory (PEROM). The device is manufactured using Atmels high density nonvolatile memory technology and is compatible with the industry standard MCS-51 instruction set and pinout. By combining a versatile 8-bit CPU with flash on a monolithic chip, the Atmel AT89C2051 is a

16、 powerful microcomputer which provides a highly flexible and cost effective solution to many embedded control applications. The AT89C2051 provides the following standard features: 2Kbytes of flash, 128bytes of RAM, 15 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architectu

17、re, a full duplex serial port, a precision analog comparator, on-chip oscillator and clock circuitry. In addition, the AT89C2051 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The idle mode stops the CPU while allowing the

18、RAM, timer/counters, serial port and interrupt system to continue functioning. The power down mode saves the RAM contents but freezer the oscillator disabling all other chip functions until the next hardware reset. 1.3 Pin Configuration 1.4 Pin Description VCC Supply voltage. GND Ground. Prot 1 Prot

19、 1 is an 8-bit bidirectional I/O port. Port pins P1.2 to P1.7 provide internal pullups. P1.0 and P1.1 require external pullups. P1.0 and P1.1 also serve as the positive input (AIN0) and the negative input (AIN1), respectively, of the on-chip precision analog comparator. The port 1 output buffers can

20、 sink 20mA and can drive LED displays directly. When 1s are written to port 1 pins, they can be used as inputs. When pins P1.2 to P1.7 are used as input and are externally pulled low, they will source current (IIL) because of the internal pullups. Port 3 Port 3 pins P3.0 to P3.5, P3.7 are seven bidi

21、rectional I/O pins with internal pullups. P3.6 is hard-wired as an input to the output of the on-chip comparator and is not accessible as a general purpose I/O pin. The port 3 output buffers can sink 20mA. When 1s are written to port 3 pins they are pulled high by the internal pullups and can be use

22、d as inputs. As inputs, port 3 pins that are externally being pulled low will source current (IIL) because of the pullups. Port 3 also serves the functions of various special features of the AT89C2051 as listed below. 1.5 Programming the Flash The AT89C2051 is shipped with the 2 Kbytes of on-chip PE

23、ROM code memory array in the erased state (i.e., contents=FFH) and ready to be programmed. The code memory array is programmed one byte at a time. Once the array is programmed, to re-program any non-blank byte, the entire memory array needs to be erased electrically. Internal address counter: the AT

24、89C2051 contains an internal PEROM address counter which is always reset to 000H on the rising edge of RST and is advanced applying a positive going pulse to pin XTAL1. Programming algorithm: to program the AT89C2051, the following sequence is recommended. 1. power-up sequence: Apply power between V

25、CC and GND pins Set RST and XTAL1 to GND With all other pins floating , wait for greater than 10 milliseconds 2. Set pin RST to H set pin P3.2 to H 3. Apply the appropriate combination of H or L logic to pins P3.3, P3.4, P3.5, P3.7 to select one of the programming operations shown in the PEROM progr

26、amming modes table. To program and Verify the Array: 4. Apply data for code byte at location 000H to P1.0 to P1.7.5.Raise RST to 12V to enable programming. 5. Pulse P3.2 once to program a byte in the PEROM array or the lock bits. The byte-write cycle is self-timed and typically takes 1.2ms. 6. To ve

27、rify the programmed data, lower RST from 12V to logic H level and set pins P3.3 to P3.7 to the appropriate levels. Output data can be read at the port P1 pins. 7. To program a byte at the next address location, pulse XTAL1 pin once to advance the internal address counter. Apply new data to the port

28、P1 pins. 8. Repeat steps 5 through 8, changing data and advancing the address counter for the entire 2 Kbytes array or until the end of the object file is reached. 9. Power-off sequence: set XTAL1 to L set RST to L Float all other I/O pins Turn VCC power off2.1 The principle of piezoelectric ultraso

29、nic generator Piezoelectric ultrasonic generator is the use of piezoelectric crystal resonators to work. Ultrasonic generator, the internal structure as shown, it has two piezoelectric chip and a resonance plate. When its two plus pulse signal, the frequency equal to the intrinsic piezoelectric osci

30、llation frequency chip, the chip will happen piezoelectric resonance, and promote the development of plate vibration resonance, ultrasound is generated. Conversely, it will be for vibration suppression of piezoelectric chip, the mechanical energy is converted to electrical signals, then it becomes t

31、he ultrasonic receiver.The traditional way to determine the moment of the echos arrival is based on thresholding the received signal with a fixed reference. The threshold is chosen well above the noise level, whereas the moment of arrival of an echo is defined as the first moment the echo signal sur

32、passes that threshold. The intensity of an echo reflecting from an object strongly depends on the objects nature, size and distance from the sensor. Further, the time interval from the echos starting point to the moment when it surpasses the threshold changes with the intensity of the echo. As a consequence, a considerable error may occur even two echoes with different intensities arriving exactly at the same time will surpass the threshold at different moments. The stronger one will surpass th