CN202057790U

CN202057790U - Vehicle-mounted ultrasonic range finder

Info

Publication number: CN202057790U
Application number: CN2011201082301U
Authority: CN
Inventors: 石钊欣
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-04-01
Filing date: 2011-04-01
Publication date: 2011-11-30
Anticipated expiration: 2021-04-01

Abstract

The utility model discloses a vehicle-mounted ultrasonic range finder, consisting of an ultrasonic emitting circuit, an ultrasonic receiving circuit, a singlechip and a displayer, wherein the singlechip is an ATmega16 singlechip; the OC1 port of the singlechip outputs 40kHz square wave signals; the ultrasonic emitting circuit is a push-pull type amplification circuit; the ultrasonic receiving circuit is characterized in that the front stage of the circuit forms an amplifier of 10000 times by NE5532 so as to amplify the receiving signals; the rear stage of the circuit adjusts the receiving signals by an LM311-8 comparator so that the signals are converted into the square wave signals and sent to a PD2 port of the singlechip by a seventh pin of the LM311-8 comparator. The vehicle-mounted ultrasonic range finder has the greatest advantages of low cost and higher system stability, has the cost of less than 50RMB and is extremely beneficial for wide generalization.

Description

Vehicle-mounted ultrasonic distance measuring apparatus

Technical field

The utility model relates to automobile mounted instrument, especially vehicle-mounted stadimeter.

Background technology

At present during automobile normal running, the place ahead safe distance relies on driver's range estimation, meets the sleet greasy weather or is difficult for judging when travelling in the tunnel, gives and drives to bring many inconvenience and some potential safety hazards.For this reason, many vehicle-mounted ultrasonic distance measuring apparatus have appearred on the market.Mostly form by ultrasonic transmit circuit, ultrasound wave receiving circuit, single-chip microcomputer and display.Because their circuit design is comparatively complicated and element is chosen problem, price is more expensive, should not promote.

Summary of the invention

The purpose of this utility model provides a kind of vehicle-mounted ultrasonic distance measuring apparatus of cheapness.

A kind of vehicle-mounted ultrasonic distance measuring apparatus is made up of ultrasonic transmit circuit, ultrasound wave receiving circuit, single-chip microcomputer and display, it is characterized in that:

Described single-chip microcomputer is the ATmega16 single-chip microcomputer, and what single-chip microcomputer OC1 end was exported is the 40kHz square-wave signal;

Described ultrasonic transmit circuit is an amplifying circuit of recommending form, this amplifying circuit is divided into two-way with the 40kHz square-wave signal that single-chip microcomputer sends, one the tunnel delivers to an electrode of ultrasonic transducer behind one-level reverser CD4049, another electrode of ultrasonic transducer is delivered on another road behind forward and backward two-stage reverser CD4049, and back level reverser CD4049 is by two reverser CD4049 parallel connection;

Described ultrasound wave receiving circuit is, this circuit prime adopts NE5532 to constitute 10000 times of amplifiers, amplify to received signal, the back level adopts the LM311-8 comparer to adjust to received signal, makes signal become the PD2 mouth that square-wave signal is delivered to the signal that receives through the 7th pin of LM311-8 comparer single-chip microcomputer.Number deliver to the PD2 mouth of single-chip microcomputer.

In order to improve the driving capability of reverser CD4049 output high level, increase the damping of ultrasonic transducer, shorten its free-running time, improve hyperacoustic emissive porwer, also can design two pull-up resistors in the described ultrasonic transmit circuit.

Principle of work is that the square-wave signal by a 40khz of ATmega16 single-chip microcomputer generation utilizes phase inverter CD4049 to carry out power amplification then, thereby improves ultrasonic signal intensity.Signal input ultrasonic transducer after the amplification produces ultrasound wave.Ultrasound wave returns after running into barrier, is received by ultrasonic detector, and is converted to electric signal.Electric signal is amplified 10000 times by the NE5532 chip after filtering, be admitted to single-chip microcomputer after the filtering.Utilize single-chip microcomputer that the time between reception and the emission is calculated, finally obtain obstacle distance, and demonstrate obstacle distance on light-emitting diode display, degree of accuracy is the cm level.Used frequency is higher than 20khz, and its good directionality is easy to obtain concentrated acoustic energy, can be used for precision ranging.

Great advantage of the present utility model is cost and the higher system stability that it is cheap.The laser range finder of selling on the market (600 yuan-3000 yuan), the cost of this product are beneficial to extensively and popularize only less than 50 yuan very much.

Description of drawings

Fig. 1 is vehicle-mounted ultrasonic distance measuring apparatus circuit structure diagram.

Among the figure: the 1-ultrasonic transmit circuit, 2-ultrasound wave receiving circuit, the 3-single-chip microcomputer, the 4-display, the 5-pull-up resistor,

Embodiment

As shown in Figure 1, vehicle-mounted ultrasonic distance measuring apparatus of the present utility model is made up of ultrasonic transmit circuit 1, ultrasound wave receiving circuit 2, single-chip microcomputer 3 and display 4, as can be seen from the figure:

Single-chip microcomputer 3 is ATmega16 single-chip microcomputers, and what the OC1 end of single-chip microcomputer 3 was exported is the 40kHz square-wave signal; Ultrasonic transmit circuit 1 is an amplifying circuit of recommending form, this amplifying circuit is divided into two-way with the 40kHz square-wave signal that single-chip microcomputer 3 sends, one the tunnel delivers to an electrode of ultrasonic transducer behind one-level reverser CD4049, another electrode of ultrasonic transducer is delivered on another road behind forward and backward two-stage reverser CD4049, and back level reverser CD4049 is by two reverser CD4049 parallel connection; Ultrasound wave receiving circuit 2 primes adopt the NE5532 operational amplifier to constitute 10000 times of NE5532 operational amplifiers, amplify to received signal, the back level adopts the LM311-8 comparer to adjust to received signal, makes signal become the PD2 mouth that square-wave signal is delivered to the signal that receives through the 7th pin of LM311-8 comparer single-chip microcomputer 3.Two pull-up resistors 5 in ultrasonic transmit circuit 1, also can designing.

Claims

1. vehicle-mounted ultrasonic distance measuring apparatus, it is accepted circuit, single-chip microcomputer and display by ultrasonic transmit circuit, ultrasound wave and forms, and it is characterized in that:

Described single-chip microcomputer is the ATmega16 single-chip microcomputer, and what single-chip microcomputer 0C1 end was exported is the 40kHz square-wave signal;

Described ultrasound wave is accepted circuit, this circuit prime adopts NE5532 to constitute 10000 times of amplifiers, amplify to received signal, the back level adopts the LM311-8 comparer to adjust to received signal, makes signal become the PD2 mouth that square-wave signal is delivered to the signal that receives through the 7th pin of LM311-8 comparer single-chip microcomputer.

2. vehicle-mounted ultrasonic distance measuring apparatus as claimed in claim 1 is characterized in that, also designing in the described ultrasonic transmit circuit has two pull-up resistors.