CN101556138A - Time-grating straight-line displacement sensor - Google Patents

Abstract

The invention provides a time grating linear displacement sensor, which belongs to displacement precision measuring devices. The sensor has two linear substrates with equal grooves to form the skeleton of the coil, which is used as a long or short ruler; it is characterized in that an excitation coil is wound on one substrate, and an induction coil is wound on the other substrate; the induction coil and the excitation coil Relative movement; the excitation coil is connected to the excitation power supply, the excitation signal and the electrical signal output by the induction coil are respectively connected to the amplifier circuit, and then after being shaped by the shaping circuit, the phase comparison is performed by a digital phase comparator; the phase difference of the two signals is determined by the interpolation The number of clock pulses is displayed, and then converted into a linear displacement value, and displayed as linear displacement data directly or after processing by the microprocessor and memory. The sensor has the advantages of simple structure, low cost, high resolution, strong anti-interference ability and easy commercialization.

Description

Grating straight-line displacement sensor when a kind of

Technical field

The invention belongs to displacement precision measurement sensor.

Background technology

Straight-line displacement and angle displacement measurement are the most basic, prevailing measurements.In order to take into account Measurement Resolution and range, many displacement transducers have adopted the grid formula structure of accurate groove on matrix, as grating, magnetic grid etc., its pulse signal that sends in motion process are carried out accumulated counts, promptly realize displacement measurement.The highdensity groove of high precision causes a lot of problems, and on the one hand groove is close more, just easy pollution the more.Seal protection no matter how, under the bad working environments of production scene, its small dust aqueous vapor all may be polluted grid line, makes it counting loss.On the other hand, groove can not be ad infinitum close, and existing density far can not satisfy the requirement of resolving power, therefore is forced to generally adopt electronic features branch mailbox, system architecture complexity.Add high-precision groove technology, make cost high.In sum, the shortcoming that exists of existing grid formula displacement transducer is: complex structure, price height, interference resistance are poor.

Summary of the invention

The objective of the invention is at above-mentioned the deficiencies in the prior art, a kind of time grating straight-line displacement sensor that straight-line displacement is measured that is used for is provided, need not accurate groove, without the electronic features branch mailbox, and with time clock as displacement mete-wand, thereby simple in structure, cost is low, resolving power is high, interference resistance is strong.

Technical scheme of the present invention is:

Grating straight-line displacement sensor when a kind of, as Fig. 1 (a), Fig. 2 and shown in Figure 5, the linear matrix that sensor has two parts to wait branch to slot constitutes the skeleton of coiling, as long chi and short chi; Be wound with drive coil on one matrix, be wound with inductive coil on another matrix; Inductive coil and drive coil relative motion; Drive coil connects excitation power supply, the electric signal of pumping signal and inductive coil output is connected respectively to amplifying circuit, again after the shaping circuit shaping, carry out the phase bit comparison by digital phase comparator, the phase differential of two paths of signals is represented by the time clock number of interpolation, be converted into the straight-line displacement value again, directly or after microprocessor and memory processes, make the straight-line displacement data presentation.

Described sensor also has two kinds of forms in addition.Sensor has the skeleton of the linear matrix formation coiling of branch flutings such as 2 or 3 parts, as long chi or short chi.A kind of form is: shown in Fig. 1 (b), be wound with the drive coil and first inductive coil on the matrix jointly; Another kind of form is: shown in Fig. 1 (c), the drive coil and first inductive coil are respectively on the motionless matrix of two relative positions.On another matrix, be wound with second inductive coil then.For these two kinds of forms, first inductive coil and drive coil all keep the locus constant, second inductive coil and drive coil relative motion.Drive coil connects excitation power supply, on two groups of inductive coils, obtain respectively the identical and phase place of frequency fixing with the two path signal that changes, the electric signal of two-way output connects amplifying circuit respectively, after the shaping circuit shaping, carries out the phase bit comparison by digital phase comparator again; The phase differential of two paths of signals is represented by the time clock number of interpolation, is converted into the straight-line displacement value again, directly or make the straight-line displacement data presentation after microprocessor and memory processes.

Above-mentioned three kinds of structures, second and third kind structure is because the inductive coil that is consistent with the locus of drive coil produces the frequency of induced signal and the frequency and the phase place of phase place and excitation power supply is consistent, so this inductive coil can omit, and become first kind of structure, directly provide or provide one road signal to participate in comparing phase by excitation power supply by certain electrical part (as transformer), so, structure is more simplified, but precision may be subjected to some disturbing effects, is applicable to the occasion that some accuracy requirements are not high.

Can independently become an assembly of elements by traditional approach as the matrix of the signal generation apparatus of sensor and coil etc., and the follow-up signal treatment circuit is formed an electric appliance box.Also can be integrated into a sensor integral body to treatment circuit together with microprocessor.The counter result can be directly output as data or figure, also can transfer to microprocessor processes, thereby constitutes intelligentized sensor.This sensor can with for example high-precision grating sensor experiment of comparing of high-precision other same type of sensor, when comparing experiment, its omnidistance systematic error can be noted, be solidificated in the storer of this sensing system, carry out error correction.When reality was used, the displacement data that provides will be the more exact value after the sensing system error having been deducted, and sensor accuracy is further improved.

That this sensor has is simple in structure, cost is low, resolving power is high, interference resistance is strong, be easy to the advantage of commercialization.

Description of drawings

Three kinds of textural association form synoptic diagram of grating straight-line displacement sensor bobbin matrix when Fig. 1 is;

The schematic diagram of generation of the signal of grating straight-line displacement sensor and data handling system when Fig. 2 is;

The long chi bobbin three-view diagram of grating straight-line displacement sensor when Fig. 3 is;

The long and short chi unitized construction synoptic diagram of grating straight-line displacement sensor when Fig. 4 is;

The coiling synoptic diagram of grating straight-line displacement sensor when Fig. 5 is.

Embodiment

Referring to Fig. 1 (a), this is first kind of structural principle of this sensor, it has first matrix 1 of relative motion and the skeleton that second matrix 2 constitutes coiling, be wound with drive coil 3 on first matrix 1, be wound with second inductive coil 4 on second matrix 2, the also relative motion of inductive coil and drive coil directly generates one the tunnel than phase signals by driving source, compares mutually with second inductive coil, 4 signals.

Referring to Fig. 1 (b), this is second kind of structural principle of this sensor, it has first matrix 1 of relative motion and the skeleton that second matrix 2 constitutes coiling, be wound with the drive coil 3 and first inductive coil 5 on first matrix 1, be wound with second inductive coil 4 on second matrix 2, drive coil 3 is relative motionless with first inductive coil 5, but second inductive coil 4 and drive coil 3 and 5 relative motions of first inductive coil, generate one road signal by first inductive coil 5, compare mutually with second inductive coil, 4 signals with drive coil 3 cobasis bodies.

Referring to Fig. 1 (c), this is the third structural principle of this sensor, it has first matrix 1 of relative motion and the skeleton that second matrix 2 constitutes coiling, also have and first matrix, 1 relative the 3rd motionless matrix 6 in addition, be wound with drive coil 3 on first matrix 1, be wound with first inductive coil 5 on the 3rd matrix 6, be wound with second inductive coil 4 on second matrix 2, drive coil 3 is relative motionless with first inductive coil 5, but second inductive coil 4 and drive coil 3 and 5 relative motions of first inductive coil, by on the 3rd matrix 6 and consistent with first matrix, 1 holding position first inductive coil 5 generate one road signal, compare mutually with second inductive coil, 4 signals.

This principle of sensors as shown in Figure 2, when drive coil passes through polyphase alternating current, to on two inductive coils, obtain the alternating signal with the excitation power supply same frequency respectively, during measurement and drive coil keeps same position and the inductive coil signal phase that do not have a relative motion is maintained fixed constant; Another inductive coil signal then produces phase shifts with the displacement of the matrix that reacts tested motion.Drive coil connects excitation power supply, on two groups of inductive coils, obtain respectively the identical and phase place of frequency fixing with the two path signal that changes, the electric signal of two-way output connects amplifying circuit respectively, after the shaping circuit shaping, carries out the phase bit comparison by digital phase comparator again; The phase differential of two paths of signals is represented by the time clock number of interpolation, is converted into the straight-line displacement value again, makes the straight-line displacement data presentation after microprocessor and memory processes.If be not provided with and the relatively-stationary inductive coil of drive coil, then can directly adopt the electric signal of pumping signal and inductive coil output to be connected respectively to amplifying circuit, it is the same that follow-up signal is handled.

Referring to Fig. 3, Fig. 4 and Fig. 5, the time grating straight-line displacement sensor constitute the metal or the nonmetal basal body 7 of branches such as the matrix adopting of coiling fluting by long chi (or scale) and short chi (or moving chi).When branches such as processing are slotted, in order to improve halving precision and to simplify technology, also can adopt the right cylinder 8 or the spheroid of two kinds of different-diameters, arrange and lay shown in Fig. 3 (a), Fig. 3 (b) and Fig. 3 (c).Cylinder that diameter is big or ball are closely arranged the one deck that fixedly becomes near matrix, and the arrangement that diameter is little is fixed in each groove between two large diameter right cylinders or the spheroid, forms another layer, thus branch such as formation bobbin of slotting naturally.Scale and moving chi adopt same structure to form, and are sample different in size.

Further as shown in Figure 4, long and short chi two part matrixes combine in the mode of rail plate.Shown in Fig. 4 (a), long chi matrix 9 provides a, b, three reference fields of c simultaneously by a metallic object, and wherein a, c face are parallel, and b face and a, c face are vertical (according to actual conditions, also can adopt modes such as dovetail groove or arc groove, then the b face is inclined-plane or arc surface etc.).The a face is long chi bobbin reference field, is used to lay the two-layer right cylinder of long chi, constitutes long chi bobbin; B, c face then are used to short chi slide block that slip helical pitch reference field is provided.Shown in Fig. 4 (b), short chi matrix 10 parts are and the b of long chi, the chute that c matches that a part is then arranged two-layer right cylinder again, constitutes short chi bobbin.Partly fit together shown in Fig. 4 (c) and Fig. 4 (d) two, short chi is installed on the long chi by the helical pitch reference field on the long chi, combine together with long chi, and can relative motion.Its simple in structure, easy processing, good integrity.Also can be according to operating position with long chi as moving chi, short chi is as scale, and the two keeps relative motion to get final product.

As shown in Figure 5, be wound with drive coil 3 and the relative first motionless inductive coil 5 on the long chi matrix, be wound with second inductive coil 4 of relative motion on the short chi matrix.The method for winding of common multipole alternating current generator is adopted in coiling, or the figure of eight, " several " word winding method and form the multipole winding that distributes along straight line.The synoptic diagram of Fig. 5 for adopting single turn line and " several " font winding method on the matrix of five equilibrium fluting, to wind the line, for clarity sake, the phase in the three phase excitation of only drawing, employing be that above-mentioned second kind of form is Fig. 1 (b) structure.When moving, scale generation relative motion, the induced signal generation phase differential on two induction windings, it is represented that with mistiming Δ T then its formula for calculating displacement is:

$x=B\frac{W}{T}\mathrm{\ΔT}=\mathrm{BfW\ΔT}=\mathrm{BfW\Σ}{p}_t---\left(2\right)$

Wherein: x-straight-line displacement, B-constant, W-coil pitch (unit is a length value), T-signal period, f-excitation power supply frequency, the mistiming that Δ T-records, ∑ p _t-time clock cumulative number.

Claims (6)

1. Two parts that have grating straight-line displacement sensor when 1, a kind of, sensor wait the linear matrix of branch fluting to constitute the skeleton of coiling, as long chi or lack chi; It is characterized in that being wound with drive coil on the matrix, be wound with inductive coil on another matrix; Inductive coil and drive coil relative motion; Drive coil connects excitation power supply, and the electric signal of pumping signal and inductive coil output is connected respectively to amplifying circuit, after the shaping circuit shaping, carries out the phase bit comparison by digital phase comparator again; The phase differential of two paths of signals is represented by the time clock number of interpolation, is converted into the straight-line displacement value again, directly or make the straight-line displacement data presentation after microprocessor and memory processes.
2. Grating straight-line displacement sensor when 2, a kind of, sensor have 2-3 partly to wait the linear matrix of branch fluting to constitute the skeleton of coiling, as long chi or lack chi; It is characterized in that being wound with the drive coil and first inductive coil on one matrix jointly, be wound with second inductive coil on another matrix for the situation that adopts two parts matrix; For the situation that adopts three part matrixes, the drive coil and first inductive coil are respectively on the motionless matrix of two relative positions, be wound with first inductive coil on the 3rd matrix, first inductive coil and drive coil keep the locus constant, second inductive coil and drive coil relative motion; In both cases, drive coil connects excitation power supply, and it is identical and phase place is fixing and the two path signal that changes to obtain frequency on two groups of inductive coils respectively, and the electric signal of two-way output connects amplifying circuit respectively, after the shaping circuit shaping, carry out the phase bit comparison again by digital phase comparator; The phase differential of two paths of signals is represented by the time clock number of interpolation, is converted into the straight-line displacement value again, directly or make the straight-line displacement data presentation after microprocessor and memory processes.
3. Grating straight-line displacement sensor when 3, as claimed in claim 1 or 2 is characterized in that inductive coil is made up of one or more inductive coil serial or parallel connections, and coil position is uniform by the space.
4. Grating straight-line displacement sensor when 4, as claimed in claim 3 is characterized in that five equilibrium fluting on the matrix is to divide two-layer arrangement and form with the right cylinder of two kinds of different-diameters or spheroid, and the tight arrangement that diameter is big fixedly becomes the one deck near matrix; The arrangement that diameter is little is fixed in each groove between two large diameter right cylinders or the spheroid, forms another layer, thus the fluting of formation five equilibrium naturally.
5. 5. grating straight-line displacement sensor when as claimed in claim 3, it is characterized in that, on the conduct matrix of long chi, both had long chi bobbin reference field, has the helical pitch reference field that slides for short chi again, short chi is installed on the long chi by the helical pitch reference field on the long chi, combines together with long chi, and slides relatively along long chi.
6. 6. grating straight-line displacement sensor when as claimed in claim 3 is characterized in that being solidified with in the described storer this time displacement transducer and other high-precision sensor omnidistance systematic error data of comparing and obtaining after the experiment, is used for error correction.

Images