CN2423566Y

CN2423566Y - Remote approaching sersor

Info

Publication number: CN2423566Y
Application number: CN 00237376
Authority: CN
Inventors: 宋立昌; 王明杰
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-06-08
Filing date: 2000-06-08
Publication date: 2001-03-14
Anticipated expiration: 2010-06-08

Abstract

The utility model relates to a remote approaching sensor, which is composed of a central processing unit and an external connection circuit, wherein, the central processing unit comprises a single chip computer; the external connection circuit comprises a power supply, an analogdigital converter, a temperature sensor, a magnetic sensor and an interface. After the power is treated by initialization, the central processing unit can obtain operation threshold and magnetic flux datum; when the magnetic material is closed, the magnetic sensor can measure current magnetic flux which is changed by digital analog and then sent to the central processing unit; after the compensation of temperature and geomagnetism, the magnetic flux is compared with the reference magnetic flux, exceeding the operation threshold and the action of the sensor, and can be output by the interface. The utility model has the advantages of high sensitivity, small size and long operating distance.

Description

Remote proximity transducer

The utility model relates to a kind of sensor, particularly a kind of high sensitivity, small size, long operating distance, the proximity transducer that can work under rugged surroundings.

In daily life and producing, use proximity transducer in a large number, with object position detection, trigger corresponding actions.At present, proximity transducer mainly contains two kinds of implementations: 1. utilize the eddy effect of metal object in high-frequency electric field, the oscillation frequency of high-frequency oscillating circuits is changed or failure of oscillation, realize that the approaching of metal object detects.This mode detection range is shorter, is generally 2mm-20mm, strengthens detection range if desired, need add large volume, gives to install and use and makes troubles.2. utilize the reflection of object, be subjected to the light inspected object near distance by photosensitive device to probing light.This mode is affected by environment big, and dust, rainwater, snowflake, high light etc. all can influence its work.

For overcoming above-mentioned deficiency, the purpose of this utility model is providing a kind of remote proximity transducer.It can descend to work in rugged surroundings such as wind, rain, snow, and operating distance long (more than or equal to 200mm), and volume is little, the location accurately, the sensing sensitivity can be according to environment temperature and magnetic field of the earth from normal moveout correction, and resistance to wear, crashworthiness presses, can move stably in a long term.It is applicable to the various needs occasion of definite object relative position non-contactly, and especially suitable automobile line ball sensing, farm labourer make stroke near switch.

The purpose of this utility model realizes by following technical proposals:

Fig. 1 is a block scheme of the present utility model, as shown in Figure 1.The utility model is made up of central processing unit 3 and external circuits, and external circuits is made up of power supply 1, interface 2, A-D converter 4, temperature sensing 5, Magnetic Sensor 6.Central processing unit 3 comprises single-chip microcomputer U2, crystal oscillator X2, capacitor C 1, C2, and its input, output terminal link to each other with external circuits, and its effect is the inner program of operation, realizes every function of proximity transducer.External circuits comprises power supply 1, interface 2, A-D converter 4, temperature sensing 5, Magnetic Sensor 6.Power supply 1 includes socket J1, capacitor C 5, C6, regulator block T1, standard of precision voltage U4, and its input end links to each other with input socket, and output terminal links to each other with other circuit, and it supplies with each circuit after with the unsettled DC power voltage stabilizing of outside input.Interface 2 includes triode T2, luminotron D1, resistance R 7, RS485 transceiver U5, its input, output link to each other with central processing unit 3, power supply 1, input plug respectively, its effect is demonstration and transmission proximity transducer testing result, and is responsible for the communication data of transmitting-receiving central processing unit 3 and host computer.A-D converter 4 includes modulus conversion chip U1, crystal oscillator X1, capacitor C 3, C4, and its input links to each other with power supply 1, Magnetic Sensor 6, central processing unit 3, and output links to each other with central processing unit 3, and the simulating signal that it sends Magnetic Sensor here is transformed to digital signal.Temperature sensing 5 includes temperature sensing chip U6, and its input, output link to each other with central processing unit 3, and its effect is the temperature of gathering surrounding environment.Magnetic Sensor 6 includes magnetoresistive transducer U3, triode Q1, Q2, capacitor C 11, C12, C13, and its output links to each other with A-D converter 4, and input links to each other with central processing unit 3, power supply 1, and its effect is to gather magnetic flux.

Because the utility model has adopted technology such as the hermetically sealed high-sensitiivty magnetic sensor of noncontact, Single-chip Controlling, temperature compensation, reduced instruction (RISC), non-volatile EEPROM storage, make and the utlity model has the sensing sensitivity, operating distance is long, volume is little, resistance to wear, crashworthiness is pressed, can be in the advantage of reliably working under the rugged surroundings.

Below will be described in further detail the utility model by specific embodiment:

Fig. 1 is a block scheme of the present utility model;

Fig. 2 is a working state schematic representation of the present utility model;

Fig. 3 is circuit theory diagrams of the present utility model;

Fig. 4 is a flow chart of the present utility model.

Divide several aspects to describe the utility model course of work below: (1) power-up initializing, external unstable power supply is added by plug J1, through capacitor C 5, C6 filtering, after the regulator block T1 voltage stabilizing, be transformed into+working power of 5V, standard of precision voltage provides+reference voltage of 2.5V simultaneously.RISC (reduced instruction set computer) single-chip microcomputer U2 get electric after, operation is solidificated in the program in its FLASH (flash) storer, at first in the electricity erasable memorizer EEPROM of U2 inside, take out operational factor, comprise local magnetic field of the earth magnetic flux, action threshold values, response magnetic field polarity, output form (latch, pulse) etc., in the random access memory ram of these data conversion storages in U2.Secondly by the 17 pin output pulse of U2, through triode Q1, Q2, capacitor C 11, C12, C13 are transformed to the required reset pulse of Magnetic Sensor U3, and U3 is resetted.Start 16 analog to digital converter U1 of high resolving power then the aanalogvoltage of Magnetic Sensor output is carried out the A/D conversion.After repeatedly measurement is averaged, as current magnetic field magnetic flux benchmark.(2) working cycle, at first start-up temperature sensor U6 is the temperature inversion of surrounding environment a digital quantity, U1 looks into the temperature inside compensation meter according to current temperature value, obtain the temperature compensation coefficient under the different temperatures, start analog to digital converter U1 then the aanalogvoltage of Magnetic Sensor output is carried out the A/D conversion, obtain the magnetic flux of current magnetic field, according to temperature compensation coefficient and local geomagnetic data benchmark magnetic flux and current magnetic flux are compensated and corrected, whether the absolute value of then judging (current magnetic flux-benchmark magnetic flux) carries out corresponding operating greater than the action threshold values.Differentiate whether receive the instruction of host computer at last, if instruction is arranged then instruct the operation of regulation.Restart to gather environment temperature then, said process is just finished a working cycle.(3) absolute value of (current magnetic flux-benchmark magnetic flux) is less than the action threshold values, and sensor does not move output, and the 18 pin output low levels of U2,19 pin are exported high level.Luminotron D1 extinguishes, triode T2 open circuit.(4) absolute value of (current magnetic flux-benchmark magnetic flux) is greater than the action threshold values, and the sensor action is exported, the 18 pin output high level (or pulse) of U2,19 pin output low levels.Luminotron D1 lights, and triode T2 is according to parameter setting conducting certain hour (output pulse) or lasting conducting.(5) receive the host computer instruction, the RS485 signal that host computer is sent here is input to serial input port 2 pin of single-chip microcomputer U2 after transceiver U5 conversion, U2 to the data of input carry out CRC check correct after, analysis instruction, if query State instruction, just after the additional CRC check of data such as each operational factor of sensor, Current Temperatures, current magnetic flux by serial delivery outlet 3 pin, be transformed into anti-interference, as to be beneficial to long-distance transmissions RS485 signal by transceiver U5 again and give host computer.If receive the adjustment parameter instruction, then adjust operational factor, and new argument is preserved among the nonvolatile memory EEPROM again according to the data received, reinitialize after being used to lose electricity.(6) be subjected to strong jamming, cause program fleet (deadlock).Single-chip microcomputer U2 inside has watchdog circuit, when program is normally moved (circulation), regularly reset to watchdog circuit, watchdog circuit can not exported reset signal, in case program fleet, watchdog circuit can not receive reset signal and overflows, and sends reset signal at once, forces single-chip microcomputer to reset and reinitializes.(7) be subjected to high-intensity magnetic field and disturb, cause magnetoresistive transducer to be magnetized and lose measuring accuracy.If the magnetic flux data that single-chip microcomputer U2 collects surpass a certain ultimate value, promptly differentiate automatically for being subjected to strong magnetic interference, recalibrate magnetoresistive transducer at 17 pin output reset pulse simultaneously.(8) be in the magnetic field of different directions, 1,4 pin of magnetoresistive transducer U3 can be exported positive and negative differential values according to magnetic direction, A-D converter U1 output valve is the upper end or the lower end of the value of mediating respectively, again through the single-chip microcomputer U2 calculating that takes absolute value, can differentiate the magnetic field of different directions, determine according to the action magnetic direction of parameter setting whether sensor moves again.

The magnetoresistive transducer that the utility model adopts has very wide magnetic field range (± 6 Gauss), very high sensitivity (85 microgasusses, magnetic field of the earth are 0.5 Gauss), very little volume.The analog to digital converter that adopts has 16 high resolving power.The single-chip microcomputer that adopts is based on reduced instruction RISC, and instruction cycletime is 100ns (10MHZ).The temperature sensor temperature-measuring range that adopts big (55 ℃---+125 ℃), resolution height (0.25 ℃).Make the utility model highly sensitive, detection range long (more than or equal to 200mm), the location is accurate, volume is little, and is strong to environmental suitability, can descend to work in rugged surroundings such as rain, snow, dirt.

Detection of magnetic field principle of the present utility model also can be used for the measurement in magnetic field.The mensuration that can be widely used in related items such as trap for automobile driving test, urban construction, environmental protection.

Claims

1. remote proximity transducer is characterized in that it is made up of central processing unit and external circuits, and central processing unit includes single-chip microcomputer, and external circuits includes power supply, analog to digital converter, temperature sensor, Magnetic Sensor and interface.

2. remote proximity transducer according to claim 1 is characterized in that: include Magnetic Sensor U3, to survey the magnetic field of sending near object, realize the position differentiation.

3. remote proximity transducer according to claim 1 is characterized in that: central processing unit comprises by single-chip microcomputer U2, is connected with external circuits with each port of U2, realizes the magnetic field differentiation with digital manner of comparison.

4. remote proximity transducer according to claim 1 is characterized in that: external circuits includes temperature sensor U6, to gather environment temperature, the detecting error that compensation temperature causes.

5. remote proximity transducer according to claim 1 is characterized in that: external circuits includes analog to digital converter U1, arrives digital quantity with the converting analogue amount.

6. remote proximity transducer according to claim 1 is characterized in that: Magnetic Sensor U3 is external by triode Q1, Q2, capacitor C 11-C14, the reset circuit that resistance R 1-R3 forms.

7. remote proximity transducer according to claim 1 is characterized in that: interface includes RS485 transceiver U5, can be at a distance and upper machine communication.

8. remote proximity transducer according to claim 1 is characterized in that: interface includes triode T2, exports transducing signal in the open collector mode.

9. remote proximity transducer according to claim 1 is characterized in that: operational factors such as the sensitivity of sensor can be adjusted in real time by the communication interface Data transmission.

10. remote proximity transducer according to claim 1 is characterized in that: single-chip microcomputer U2 preserves operational factor with nonvolatile memory.

11. remote proximity transducer according to claim 1 is characterized in that: single-chip microcomputer U2 eliminates the deviation that earth magnetism causes with the local magnetic field of the earth data of preserving in the nonvolatile memory.