计（论文）英文翻译 Ultrasonic ranging system design Publicationtitle: Sensor Review. Bradford: 1993. Vol. 13ABSTRACT：Ultrasonic ranging technology has wide using worth in many fields，such as the industriallocale，vehicle navigation and sonar engineering．Now it has been used in level measurement，self-guided autonomous vehicles fieldwork robots automotive navigation，air and underwater targetdetection，identification，location and so on．So there is an important practicing meaning to learn theranging 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，aportable ultrasonic ranging system based on the single chip processor was developed．Keywords：Ultrasound r，Ranging System，Single Chip

Processor1.Introductive With the development of science and technology the improvement of peoplesstandard of living speeding up the development and construction of the city. urbandrainage system have greatly developed their situation is constantly improving. Howeverdue to historical reasons many unpredictable factors in the synthesis of her time the citydrainage system. In particular drainage system often lags behind urban construction.Therefore there are often

good building excavation has been building facilities to upgradethe drainage system phenomenon. It brought to the city sewage and it is clear to the citysewage and drainage culvert in the sewage treatment system. comfort is very important topeoples lives. Mobile robots designed to clear the drainage culvert and the automaticcontrol system Free sewage culvert clear guarantee robot the robot is designed to clear theculvert sewage to the core. Control System is the core component of the development ofultrasonic range finder. Therefore it is very important to design a good ultrasonic rangefinder.2. A principle of ultrasonic distance measurement ‐7‐ 毕业设计（论文）英文翻译2.1 The principle of piezoelectric ultrasonic 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 aresonance plate. When its two plus pulse signal the frequency equal to the

intrinsicpiezoelectric oscillation frequency chip the chip will happen piezoelectric resonance andpromote the development of plate vibration resonance ultrasound is generated. Converselyif the two are not inter-electrode voltage when the board received ultrasonic resonance itwill

be for vibration suppression of piezoelectric chip the mechanical energy is convertedto electrical signals then it becomes the ultrasonic receiver. The traditional way to determine the moment of the echos arrival is based onthresholding the received signal with a fixed reference. The threshold is chosen well abovethe noise level whereas the moment of arrival of an echo is defined as the first moment theecho signal surpasses that threshold. The intensity of an echo reflecting from an objectstrongly depends on the objects nature size and distance from the sensor. Further the timeinterval from the echos starting point to the moment when it surpasses the thresholdchanges with the intensity of the echo. As a consequence a considerable error may occurEven two echoes with different intensities arriving exactly at the same time will surpass thethreshold at different moments. The stronger one will surpass the threshold earlier than theweaker so it will be considered as belonging to a nearer object.2.2The principle of ultrasonic distance measurement Ultrasonic transmitter in a direction to launch ultrasound in the moment to launch thebeginning of time at the same time the spread of ultrasound in the air obstacles on his wayto return immediately the ultrasonic reflected wave received by the

receiver immediatelystop the clock. Ultrasound in the air as the propagation velocity of 340m / s according tothe timer records the time t we can calculate the distance between the launch distancebarrier s that is: s 340t / 23.Ultrasonic Ranging System for the Second Circuit Design ‐8‐ 毕业设计（论文）英文翻译 System is characterized by single-chip microcomputer to control the use of ultrasonictransmitter and ultrasonic receiver since the launch from time to time single-chip selectionof 8751 economic-to-use and the chip has 4K of ROM to facilitate programming. Circuitschematic diagram shown in Figure 2. Figure 1 circuit principle diagram ‐9‐ 毕业设计（论文）英文翻译3.1 40 kHz ultrasonic pulse generated with the launch Ranging system using the ultrasonic sensor of piezoelectric ceramic sensors UCM40its operating voltage of the pulse signal is 40kHz which by the single-chip implementationof the following procedures to generate.puzel: mov 14h 12h ultrasonic firing continued 200mshere: cpl p1.0 output 40kHz square wave nop nop nop djnz 14h here ret Ranging in front of single-chip termination circuit P1.0 input port single chipimplementation of the above procedure the P1.0 port in a 40kHz pulse output signal afteramplification transistor T the drive to launch the first ultrasonic UCM40T issued 40kHzultrasonic pulse and the

continued launch of 200ms. Ranging the right and the left side ofthe circuit respectively then input port P1.1 and P1.2 the working principle and circuit infront of the same location.3.2 Reception and processing of ultrasonic Used to receive the first launch of the first pair UCM40R the ultrasonic pulsemodulation signal into an alternating voltage the op-amp amplification IC1A and afterpolarization IC1B to IC2. IC2 is locked loop with audio decoder chip LM567 internalvoltage-controlled oscillator center frequency of f0 1/1.1R8C3 capacitor C4 determinetheir target bandwidth. R8-conditioning in the launch of the carrier frequency on theLM567 input signal is greater than 25mV the output from the high jump 8 feet into alow-level as interrupt request signals to the single-chip processing. Ranging in front of single-chip termination circuit output port INT0 interrupt thehighest priority right or left location of the output circuit with output gate IC3A accessINT1 port single-chip while single-chip P1.3 and P1. 4 received input IC3A interrupted ‐10‐ 毕业设计（论文）英文翻译by the process to identify the source of inquiry to deal with interrupt priority level for thefirst left right after. Part of the source code is as follows:receive1: push psw push acc clr ex1 related external interrupt 1 jnb p1.1 right P1.1 pin to

0 ranging from right to interrupt serviceroutine circuit jnb p1.2 left P1.2 pin to 0 to the left ranging circuit interruptservice routinereturn: SETB EX1 open external interrupt 1 pop acc pop psw retiright: ... right location entrance circuit interrupt service routine Ajmp

Returnleft: ... left Ranging entrance circuit interrupt service routine Ajmp Return3.3 The calculation of ultrasonic propagation time When you start firing at the same time start the single-chip circuitry within the timerT0 the use of timer counting function records the time and the launch of ultrasonicreflected wave received time. When you receive the ultrasonic reflected wave the receivercircuit outputs a negative jump in the end of INT0 or INT1 interrupt request generates asignal single-chip microcomputer in response to external interrupt request theimplementation of the external interrupt service subroutine read the time differencecalculating the distance . Some of its source code is as follows:RECEIVE0: PUSH PSW PUSH ACC CLR EX0 related external interrupt 0 .