CN101476869A - Multi-point type displacement meter for monitoring displacement of earth historic relics cliff body and its use method - Google Patents

Abstract

The invention relates to a multipoint displacement meter for monitoring the displacement of a relic cliff body and a using method thereof. The multipoint displacement meter for monitoring the displacement of the relic cliff body comprises a measuring tube, a movable magnetic ring and a detection device, wherein a measuring bar consists of two coaxial circular tubes; an outer tube is made of anticorrosive materials; the center of the measuring bar is a waveguide tube which is made of magnetostrictive materials; the movable magnetic ring is an annular magnet and sleeved on the measuring bar and can freely slide; and one end of the movable magnetic ring is fixed on an object to be detected, namely the soil relic cliff body, and the other end of the movable magnetic ring is connected with the detection device. Displacement monitoring of the soil relic cliff body is realized by utilizing the magnetostrictive principle and the action of magnetic fields on magnetostrictive wires, namely by calculating the accurate position of a magnetic field crosspoint through utilization of the time that strain pulse signals generated when two different magnetic fields are intersected are detected. The displacement monitoring device has the advantages of high precision, non-contact, long service life, high stability, convenient assembly and the like. Because a detection element is non-contact, a sensor cannot be worn even under the condition of continuous repeated detection, the detection reliability and the service life can be greatly improved, and the safety of staffs and cultural relics during reinforcement is guaranteed.

Description

A kind of multipoint mode displacement meter and using method thereof of monitoring precipice, native ruins displacement body

Technical field

The invention belongs to the displacement monitoring technical field, concretely, relate to a kind of multi-point displacement device and using method thereof that is used to monitor the distortion of surface, precipice, native ruins.

Background technology

The domestic Silk Road ancient site of China mainly contains the Cave Temple and earth construction site two big classes, and totally 1200 many places wherein except that the world cultural heritage Mo kao grotto at Dunhuang, also have up to a hundred State Protected Historic Sites.These ancient sites are with a long history, and culture and scientific meaning are very abundant, and high archaeology, history culture and scientific value are arranged.The main disease that present native ruins suffer is that serious weathering and wind erosion, weathering are destroyed, and forms many gullies and precipice body on sheer, and severe patient makes the partial collapse of native ruins, causes catastrophic collapse.For example be positioned at the Ruins of the Ancient City of Jiaohe of west, Turpan, Xinjiang Uygur Autonomous Regions 10km, be built in before B.C. 3rd century, occupy an important position on China's Western Regions history, because nature and human factor, the historical relic body and the precipice body of Ruins of the Ancient City of Jiaohe have produced severe diseases.State Cultural Relics Bureau's project verification in 2006 implements to speedily carry out rescue work reinforcing engineering to Ruins of the Ancient City of Jiaohe, and wherein body reinforcing engineering in precipice accounts for the overwhelming majority of this reinforcing engineering amount.

Find through literature search prior art; Chinese patent discloses " mao bamboo reinforcement Composite Bolt " (publication number: CN2793196Y;); this technology provides a kind of native ruins bolt anchorage technology that is suitable for the big scale of construction, the soft soil body, good endurance, has been widely used at present in the reinforcing and protection engineering of native ruins crag bodies (precipice body).

But because the limit that some precipice bodies to be reinforced are on the verge of avalanche or drop in order to ensure the safety of personnel in the reinforcing process and historical relic, need be implemented distortion (displacement) monitoring to reinforcing precipice body overall process.

Summary of the invention

The objective of the invention is to provides a kind of multipoint mode displacement meter of monitoring precipice, native ruins displacement body at the characteristics in the body reinforcement protection engineering of precipice, native ruins, is used for the displacement monitoring of native ruins reinforcing engineering, guarantees the safety of personnel and historical relic in the reinforcing process.

Another object of the present invention provides a kind of using method of monitoring the multipoint mode displacement meter of precipice, native ruins displacement body.

The objective of the invention is to be achieved through the following technical solutions:

A kind of multipoint mode displacement meter of monitoring precipice, native ruins displacement body is made up of measuring staff, movable magnet ring and pick-up unit.Measuring staff is made up of two coaxial pipes: outer tube is made by anticorrosive; The center is the waveguide that is made of magnetostriction materials, and movable magnet ring is a ringshaped magnet, is enclosed within on the measuring staff to be free to slide, and an end is fixed on the measured target thing---on the body of precipice, native ruins, the other end is connected on the pick-up unit.

A kind of using method of monitoring the multipoint mode displacement meter of precipice, native ruins displacement body is the steps include:

1), at the scene movable magnet ring is fixed and the both sides, crack (k) that may be subjected to displacement;

2), measuring staff is passed movable magnet ring, and assurance activity magnet ring can move freely on measuring staff, and an end is fixed in the measured target thing, and the other end is connected on the pick-up unit;

3), pick-up unit 3 inserts computer management systems, signal enters the PLC system by the RS-485 bus through 485 modules of PLC, the deal with data of PLC is sent into Siemens OS77 active station (CELSIUS400) by the Profibus bus, does further processing by software;

4), input instruction on computers, make pick-up unit 3 just produce pulse excitation at set intervals at interval, caudad advance with the light velocity certainly along waveguide in the magnetic field that pulse excitation produces, when intersecting with movable magnet ring, waveguide produces a mechanical strain pulse in joining, and from then on puts with the velocity of sound and to return to pick-up unit through measuring staff, and strain-pulse detects with regard to detected device; When movable magnet ring moves to new position, redefine above-mentioned measurement, just can obtain the displacement continuous curve of surface, precipice, native ruins;

5), rate of displacement is if reach per hour 3mm, the precipice body that shows reinforcing has the danger of avalanche of being on the verge of or drop, take corresponding emergency measure, to ensure workmen's safety.

6), contrast is implemented the displacement curve before and after the reinforcing engineering, the effect of evaluation reinforcing engineering.

Principle of work of the present invention mainly is to utilize the combination of magnetic effect and ultrasonic effect to reach the measurement purpose.As shown in Figure 1, the pulse producer in the pick-up unit at first gets on the magnetostrictive waveguide pipe in measuring staff and applies an electric impulse signal, and this electric pulse is followed a ring-like magnetic field simultaneously, transmits downwards along waveguide with the light velocity.When this magnetic field runs into the longitudinal magnetic field that magnet in the movable magnet ring produces, will carry out vector superposedly with it, form a spiral magnetic field.When the resultant magnetic field changed formation spirality magnetic field, the magnetostrictive waveguide pipe can produce along the dilatation in spirality magnetic field, causes waveguide to produce torsional deformation, thus excitement of torsional ripple (or returning pulse).This torsional wave passes back in the pick-up unit with hyperacoustic form along waveguide.According to Villari effect, during magnetostriction materials generation physical deformation, can in magnetostriction materials, cause the variation of magnetic field intensity, therefore, magnetic flux by cell winding will change, and will produce an induction electromotive force that can be detected in pick-up unit.The ultrasonic velocity of wave propagation of reversing is a constant (about 2838m/s).Therefore, be carved into the mistiming that detects induction electromotive force from one of pulsed emission current and multiply by this fixed speed, just can accurately calculate the exact position of magnet (movable magnet ring).

The present invention has following technological merit:

1, high precision

Because multipoint displacement meter of the present invention is to determine tested displacement by measuring transponder pulse with the mistiming of returning pulse, so measuring accuracy is high.It is non-linear less than 0.05%FS, and repeatability is less than 0.001%FS, and resolution is less than 0.002%FS, and precision is much higher than other displacement monitors.

2, multimetering

Because the pick-up unit in the multipoint displacement meter of the present invention can detect the continuous magnetic wave that is produced by same transponder pulse,, realize multimetering so on same measuring staff, can be equipped with 2-10 movable magnet ring.

3, reliability height, failure rate is low, and the life-span is long

Because the sensing element (waveguide) and the measured medium noncontact of multipoint displacement meter of the present invention, so, can not cause any wearing and tearing to sensor though measuring process is constantly to repeat yet.Therefore, it has the advantage that functional reliability height, fault are low, the life-span is long, is fit to various rugged surroundings.

4, be convenient to automatic management

The general output signal interface of pick-up unit in the multipoint displacement meter of the present invention adopts normalized current signal or the RS-485 digital signal interface of 4 ~ 20mA, can directly insert PLC, DCS system or other computer management systems, be convenient to microcomputer signal is handled, realize monitoring automatically.

Description of drawings

Fig. 1 is the multipoint mode displacement meter scheme of installation at the scene of monitoring precipice, native ruins displacement body.

Fig. 2 is the structural representation of the multipoint mode displacement meter of monitoring precipice, native ruins displacement body.

Fig. 3 is native ruins field measurement displacement curve figure.

Embodiment

Below in conjunction with embodiment and accompanying drawing the present invention is further described again:

Embodiment

As shown in Figure 1 and Figure 2, a kind of multipoint mode displacement meter of monitoring precipice, native ruins displacement body is made up of measuring staff 1, movable magnet ring 2 and pick-up unit 3.Measuring staff 1 is made of two coaxial pipes: the outer tube that anticorrosive is made is the polyflon cover; The center is the waveguide that is made of magnetostriction materials (NWDZ-L, Changzhou receive Microtronics A/S produce), movable magnet ring 2 is a ringshaped magnet, be enclosed within on the measuring staff 1 and be free to slide, one end is fixed on the measured target thing---and on the body of precipice, native ruins, the other end is connected on the pick-up unit 3 (model: KYCM-L, last Haikang space measure and control instrument company limited produce).

Monitor the using method of the multipoint mode displacement meter of precipice, native ruins displacement body:

The about 20m of precipice, native ruins height that is reinforced, ground surface has 2 observable cracks that are about 15m, wide about 1cm, for the safety that guarantees reinforcing engineering and check reinforcing engineering effect, the precipice body has been carried out the multi-point displacement monitoring, the steps include:

1), at interval 5m beats the timber of the 1m degree of depth on the body of precipice, and movable magnet ring 2 usefulness screws are fixed on the timber.

2), have the measuring staff 1 of waveguide to pass movable magnet ring 2 inside, movable magnet ring 2 can move freely on measuring staff 1, and an end is fixed in measured target, and the other end is connected on the pick-up unit 3.Pick-up unit 3 is pulse producers, and the output signal interface adopts normalized current signal or the RS-485 digital signal interface of 4～20mA, can directly insert PLC, DCS system or other computer management systems.

3), pick-up unit 3 inserts computer management systems, signal enters the PLC system by the RS-485 bus through 485 modules of PLC, the deal with data of PLC is sent into Siemens OS77 active station (CELSIUS400) by the Profibus bus, does further processing by software;

4), input instruction on computers, make pick-up unit 3 every 1 hour by producing pulse excitation, caudad advance from top with the light velocity along waveguide in the magnetic field that this pulse excitation produces, when intersecting with movable magnet ring 2, because magneto-striction phenomenon, waveguide produces a mechanical strain pulse in joining, and from then on puts through measuring staff 1 to pick-up unit 2 passbacks with the velocity of sound, and this strain-pulse detects with regard to detected device 3.Therefore, from launching an active pulsating wave to receiving a strain-pulse ripple, time between this is exactly (the time of having ignored the operation of active ripple herein time that the velocity of sound is transmitted in waveguide (1), actual influence has only 0.0001%), the known velocity of sound (fixed amount is 3000m/s) and passing time, this distance just can be determined.When movable magnet ring moves to new position, redefine above-mentioned measurement, just can obtain surface, precipice, native ruins every 1 hour displacement continuous curve (see figure 3).

5), because the generation of pulse excitation is sent every 1 hour automatically by computing machine, can realize 24 hours automatic displacement monitorings of all-weather.

6) if rate of displacement reaches per hour 3mm, the precipice body that shows reinforcing has the danger of avalanche of being on the verge of or drop, take corresponding emergency measure, to ensure workmen's safety, does not reach this displacement limits value among this embodiment.

7), as shown in Figure 3, along with the progress of reinforcing engineering, the displacement trend of surface, precipice is time period A＜time period B〉time period C, i.e. finishing along with reinforcing engineering, displacement is reducing gradually, tend towards stability substantially in C time period displacement, thereby the effect of proof reinforcing engineering is very significant.

Claims (3)

1, a kind of multipoint mode displacement meter of monitoring precipice, native ruins displacement body is made up of measuring staff, movable magnet ring and pick-up unit, and it is characterized in that measuring staff is made up of two coaxial pipes: outer tube is made by anticorrosive; The center is the waveguide that is made of magnetostriction materials, and movable magnet ring (2) is a ringshaped magnet, is enclosed within on the measuring staff (1) to be free to slide, and an end is fixed on the measured target thing---on the body of precipice, native ruins, the other end is connected on the pick-up unit (3).

2, a kind of device multipoint displacement meter of monitoring the displacement of native ruins according to claim 1, the outer tube that above-mentioned anticorrosive is made is the polyflon cover.

3, a kind of using method of monitoring the multipoint mode displacement meter of precipice, native ruins displacement body as claimed in claim 1 is:

1) at first movable magnet ring (2) is fixed in the both sides, crack (k) that precipice, native ruins body may be subjected to displacement at the scene;

2) measuring staff passes movable magnet ring (2), and movable magnet ring (2) moves freely on measuring staff (1), and an end is fixed in the measured target thing, and the other end is connected on the pick-up unit (3);

3), pick-up unit (3) inserts computer management system, signal enters the PLC system by the RS-485 bus through 485 modules of PLC, the deal with data of PLC is sent into Siemens OS77 active station (CELSIUS400) by the Profibus bus, does further processing by software;

4), to input instruction on the computing machine, make pick-up unit (3) just produce pulse excitation at set intervals at interval, caudad advance from top with the light velocity along waveguide in the magnetic field that pulse excitation produces, when intersecting with movable magnet ring (2), waveguide produces a mechanical strain pulse in joining, and from then on put through measuring staff (1) to pick-up unit (3) passback with the velocity of sound, strain-pulse detects with regard to detected device (3); When movable magnet ring (2) moves to new position, redefine above-mentioned measurement, just can obtain the displacement continuous curve of surface, precipice, native ruins;

5), rate of displacement reaches per hour 3mm, the precipice body that shows reinforcing has the danger of avalanche of being on the verge of or drop, should take corresponding emergency measure, to ensure workmen's safety;

6), contrast is implemented the displacement curve before and after the reinforcing engineering, the effect of evaluation reinforcing engineering.

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