CN112212974A

CN112212974A - Output method and device for accurately controlling spectrum of monochromator

Info

Publication number: CN112212974A
Application number: CN202011046668.1A
Authority: CN
Inventors: 杨松; 丛佳鑫; 丁金延; 马洪建
Original assignee: Jilin Yuanda Optics Detection Technology Co ltd
Current assignee: Jilin Yuanda Optics Detection Technology Co ltd
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2021-01-12

Abstract

A method and a device for accurately controlling the output of a monochromator spectrum relate to the technical field of spectrum control, and aiming at the technical problems in the prior art, the device is characterized in that a stepping motor is fixed on a gear bracket; a rotating shaft of the stepping motor penetrates through the gear bracket to fix the small synchronous belt gear; the small synchronous belt gear is meshed with the large synchronous belt gear through a synchronous belt; the first rotating shaft passes through the gear bracket to fix the large synchronous belt gear and the small straight-tooth conical gear; the small straight-tooth conical gear is meshed with the large straight-tooth conical gear; the large straight-tooth conical gear is fixed on the second rotating shaft; the upper end of the second rotating shaft is connected, and the lower end of the second rotating shaft is connected with an encoder; the second rotating shaft is fixedly arranged. The method greatly reduces the accumulated error caused by the inconsistency of the rotating angle of the synchronous motor and the pulse value when the synchronous motor outputs. The mechanical structure is simple, the production cost is low, and the performance is stable when in use, so the method has the significance of universal use.

Description

Output method and device for accurately controlling spectrum of monochromator

Technical Field

The invention relates to the technical field of spectrum control, in particular to a method and a device for accurately controlling the output of a monochromator spectrum.

Background

Monochromators are devices used to study and analyze substance spectra, and are currently widely used in various fields such as military, industry, agriculture, medical care, and scientific research. The monochromator capable of controlling the spectrum output is the most universal measuring instrument, whether the output spectrum of the monochromator can be rapidly and accurately controlled or not is an important index selected by the market for the monochromator.

The currently used methods for realizing the system for accurately controlling the rotation angle of the grating are probably as follows:

one is to directly drive the grating by a precise stepping motor, and the rotation angle of the grating is determined by the step number of the precise stepping motor. However, in the scheme, the precision stepping motor is easy to lose steps during working, so that the free error is large, and the scheme is difficult to realize accurate control of spectral output.

The method adopts a direct current brushless motor and a high-precision optical encoder to form a control system for direct drive control, and the rotation angle of the grating can be accurately controlled in the mode, but the accumulated error of the high-precision optical encoder is large, and meanwhile, the grating greatly improves the requirement on the resolution ratio of the optical encoder under the requirement on the high precision of the rotation angle, and the cost is high.

The grating is controlled by the combination of a stepping motor, a worm gear and a photoelectric switch, the step number of the stepping motor and the rotation angle of the grating are mainly displayed by the photoelectric switch, although the grating can be controlled by the method, errors are totally accumulated in 3600, so that the accumulated errors are overlarge, and the grating cannot be accurately controlled.

Disclosure of Invention

The invention provides a method and a device for accurately controlling the output of a monochromator spectrum, aiming at the technical problems in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

an output method for accurately controlling the spectrum of a monochromator is characterized by comprising the following steps:

step one, when a stepping motor works, electromagnetic pulse is converted into mechanical motion, a rotating shaft of the stepping motor drives a small synchronous belt gear connected with the rotating shaft to start rotating to drive a large synchronous belt gear meshed with a synchronous belt of the stepping motor to drive, and the small synchronous belt gear, the synchronous belt and the large synchronous belt gear form a primary speed reduction transmission structure; the transmission ratio of the synchronous belt gear set of the primary speed reduction transmission structure is K1;

and step two, the small straight-tooth conical gear connected with the first rotating shaft penetrating through the gear bracket rotates, and the large straight-tooth conical gear set and the small straight-tooth conical gear set are meshed with each other to form a secondary speed reduction structure. The transmission ratio of the conical gear set of the two-stage speed reducing structure is K2;

driving a second rotating shaft arranged on the fixed plate by a large straight-tooth conical gear meshed with a small straight-tooth conical gear, and driving a grating and an encoder which are connected up and down to rotate by the second rotating shaft;

and step four, detecting the pulse accumulated value of the stepping motor once when the encoder rotates the unit code value, and adjusting the pulse value of the stepping motor when the pulse accumulated value of the stepping motor is detected not to correspond to the code value when the encoder is driven to detect, so that the adjusted pulse value of the stepping motor is aligned to the code value of the encoder.

2. The device for accurately controlling the output method of the monochromator spectrum according to claim 1, wherein the device comprises a stepping motor, a small synchronous belt gear, a synchronous belt, a large synchronous belt gear, a gear bracket, a first rotating shaft, a small straight-tooth conical gear, a large straight-tooth cone, a second rotating shaft, an encoder, a grating and a fixing plate; the stepping motor is fixed on the gear bracket; a rotating shaft of the stepping motor penetrates through the gear bracket to fix the small synchronous belt gear; the small synchronous belt gear is meshed with the large synchronous belt gear through a synchronous belt; the first rotating shaft passes through the gear bracket to fix the large synchronous belt gear and the small straight-tooth conical gear; the small straight-tooth conical gear is meshed with the large straight-tooth conical gear; the large straight-tooth conical gear is fixed on the second rotating shaft; the upper end of the second rotating shaft is connected, and the lower end of the second rotating shaft is connected with an encoder; the second rotating shaft is fixedly arranged.

The invention has the beneficial effects that: the invention adopts the encoder with lower precision to control the stepping motor, so that the encoder and the stepping motor form a semi-closed loop control system, and the system is used for accurately controlling the output of the monochromator spectrum. The method greatly reduces the accumulated error caused by the inconsistency of the rotating angle of the synchronous motor and the pulse value when the synchronous motor outputs. The invention has simple mechanical structure, low production cost and stable performance when in use, thus the method has the significance of universal use.

Drawings

Fig. 1 is a structural view of an apparatus for precisely controlling an output method of a monochromator spectrum according to the present invention.

Fig. 2 is a side view of fig. 1.

In the figure: 1. the device comprises a stepping motor, 2, a small synchronous belt gear, 3, a synchronous belt, 4, a large synchronous belt gear, 5, a gear bracket, 6, a first rotating shaft, 7, a small straight-tooth conical gear, 8, a large straight-tooth conical gear, 9, a second rotating shaft, 10, an encoder, 11, a grating, 12 and a fixing plate.

Fig. 3 is a schematic diagram of the wavelength precision and angle precision conversion relationship of the grating 11.

In fig. 3, H1 is the position of the grating 11 at 00, P1 is the spectral value 275NM output by the grating 11 at H1, H2 is the position at which the grating 11 is rotated 100, and P2 is the spectral value 550NM output by the grating 11 at H1.

Fig. 4 is a schematic view of the principle of increasing the accuracy of the stepping motor 1.

In fig. 4, D is a rotation angle value of the rotating shaft of the stepping motor 1 when the stepping motor 1 outputs the unit pulse, and B is a rotation angle value of the unit pulse output by the stepping motor 1 after the unit pulse passes through the primary deceleration structure and the secondary deceleration structure to increase the angle accuracy.

Fig. 5 is a schematic diagram of the encoder 10 controlling the stepping motor 1.

In fig. 5, the length of the arc a represents the code value number (i.e. the start point and the end point of the discrete value) corresponding to the unit pulse of the encoder 10, and the length of the arc B represents the code value (i.e. the insertion value) of the stepping motor 1 that the unit pulse is output after the angular precision is increased to drive the encoder 10 to move.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1 and 2, a device for accurately controlling an output method of a monochromator spectrum includes a stepping motor 1, a small synchronous belt gear 2, a synchronous belt 3, a large synchronous belt gear 4, a gear bracket 5, a first rotating shaft 6, a small straight bevel gear 7, a large straight bevel gear 8, a second rotating shaft 9, an encoder 10, a grating 11, and a fixing plate 12.

The stepping motor 1 is fixed on the gear bracket 5; a rotating shaft of the stepping motor 1 penetrates through a gear bracket 5 to fix a small synchronous belt gear 2; the small synchronous belt gear 2 is meshed with the large synchronous belt gear 4 through a synchronous belt 3; the first rotating shaft 6 penetrates through the gear bracket 5 to fix the large synchronous belt gear 4 and the small straight-tooth conical gear 7; the small straight-tooth conical gear 7 is meshed with the large straight-tooth conical gear 8; the big straight bevel gear 8 is fixed on the second rotating shaft 9.

The upper end of the second rotating shaft 9 is connected with a grating 11, and the lower end of the second rotating shaft 9 is connected with an encoder 10.

The second rotating shaft 9 is mounted on the fixed plate 12.

The connection between the machinery in this device all has the nut to fix, and can carry out the tensioning between big and small hold-in range gear and handle, can eliminate mechanical clearance and transmission after the tensioning and slide, eliminate the transmission error in the one-level transmission device promptly. In the secondary speed reducer, the large straight-tooth conical gear 8 and the small straight-tooth conical gear 7 are in a split assembly mode, and the small straight-tooth conical gear 7 can translate along the axis direction of transmission, so that the small straight-tooth conical gear 7 is pushed tightly and fixed. This adjustment replaces the traditional worm and gear form. The mechanical clearance between the straight bevel gear sets can be eliminated, and gapless precision transmission is realized.

A method for accurately controlling the output of a monochromator spectrum comprises the following steps:

step one, when the stepping motor 1 works, the electromagnetic pulse is converted into mechanical motion. The small synchronous belt gear 2 connected with the stepping motor 1 through the rotating shaft drive starts to rotate, the large synchronous belt gear 4 meshed with the synchronous belt 3 is driven to transmit, and the small synchronous belt gear, the synchronous belt and the large synchronous belt gear form a primary speed reduction transmission structure. The transmission ratio of the synchronous belt gear set of the primary speed reducing transmission structure is K1.

And step two, a small straight bevel gear 7 connected with a first rotating shaft 6 penetrating through the gear bracket 5 rotates. The big and small straight-tooth conical gear sets are meshed with each other to form a two-stage speed reduction structure. The transmission ratio of the conical gear set of the two-stage speed reduction structure is K2.

And step three, a second rotating shaft 9 arranged on a fixed plate 12 is driven by a large straight-tooth conical gear 8 meshed with a small straight-tooth conical gear 7, and the grating 11 and the encoder 10 which are connected up and down are driven by the second rotating shaft to rotate.

And step four, detecting the pulse accumulated value of the stepping motor 1 once when the encoder 10 rotates the unit code value, and adjusting the pulse value of the stepping motor 1 when detecting that the pulse accumulated value of the stepping motor 1 does not correspond to the code value detected by driving the encoder 10, so that the adjusted pulse value of the stepping motor 1 is aligned to the code value of the encoder 10.

In order to more clearly control the output of the monochromator spectrum, we will list the examples below. The invention is not to be considered as limited to the particular embodiments shown, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

A stepping motor 1 which needs X (X12000) pulses to rotate one circle is adopted, and the stepping motor 1 is used as a prime mover of the whole system. The angular accuracy D of the unit rotation of this stepping motor 1 is:

the grating 11 with wavelength precision of 0.1NM, spectral range of λ 1- λ 2(λ 1-275 NM- λ 2-500 NM) and effective rotation angle α (α -100) is used, and the angle J required for the grating 11 to rotate per wavelength is:

the encoder 10 of Y (215) BIT is used, and the encoder 10 of this accuracy is used as a controller of the entire system. The required rotation angle a of the encoder 10 when changing the unit code value is:

A＝360×3600÷Y＝360×3600÷2¹⁵＝39S

step one, when the stepping motor 1 of 12000 works, the electromagnetic pulse is converted into mechanical motion. A rotating shaft of a stepping motor 1 drives a small synchronous belt gear 2 connected with the rotating shaft to start rotating, and drives a large synchronous belt gear 4 meshed with a synchronous belt 3 to drive, so that a primary speed reduction transmission structure is formed. The transmission ratio of the synchronous belt gear set of the primary speed reducing transmission structure is K1(K1 is 8).

And step two, a small straight bevel gear 7 connected with a first rotating shaft 6 penetrating through the gear bracket 5 rotates. The big and small straight-tooth conical gear sets are meshed with each other to form a two-stage speed reduction structure. The transmission ratio of the conical gear set of the two-stage speed reduction structure is K2(K2 is 10). The rotation precision of the stepping motor is improved to the control grating rotation which can be accurate by the primary speed reduction transmission structure and the secondary speed reduction structure in the transmission process, and the improved precision B is as follows:

B＝D÷k₁÷k₂＝108÷8÷10＝1.3s。

and step three, the large straight-tooth conical gear 8 meshed with the small straight-tooth conical gear 7 drives a second rotating shaft 9 arranged on a fixing plate 12, and the second rotating shaft 9 drives a grating 11 and an encoder 10 which are connected up and down to rotate.

When the encoder 10 rotates 39S, the number N of theoretical pulses that the stepping motor 1 needs to output is:

N＝A÷B＝39÷1.3＝30。

and step four, detecting the pulse accumulated value of the stepping motor 1 for 30 times every time the encoder 10 rotates for 39S, and when the pulse accumulated value of the stepping motor 1 is detected not to correspond to the code value of the encoder 10 in detection, adjusting the pulse value of the stepping motor 1 to align the adjusted pulse value of the stepping motor 1 with the code value of the encoder 10, namely, aligning the rotation angle of the grating 11 with the code value of the encoder 10, so that the accumulated error of the rotation of the grating 11 is greatly reduced, and the output precision of the spectrum is improved.

Claims

1. An output method for accurately controlling the spectrum of a monochromator is characterized by comprising the following steps:

step one, when a stepping motor (1) works, electromagnetic pulses are converted into mechanical motion, a rotating shaft of the stepping motor (1) drives a small synchronous belt gear (2) connected with the rotating shaft to start rotating to drive a large synchronous belt gear (4) meshed with a synchronous belt (3) to transmit, and the small synchronous belt gear, the synchronous belt and the large synchronous belt gear form a primary speed reduction transmission structure; the transmission ratio of the synchronous belt gear set of the primary speed reduction transmission structure is K1;

and step two, a small straight-tooth conical gear (7) connected with a first rotating shaft (6) penetrating through the gear bracket (5) rotates, and the large straight-tooth conical gear set and the small straight-tooth conical gear set are meshed with each other to form a secondary speed reduction structure. The transmission ratio of the conical gear set of the two-stage speed reducing structure is K2;

a large straight-tooth conical gear (8) meshed with the small straight-tooth conical gear (7) drives a second rotating shaft (9) arranged on a fixing plate (12), and the second rotating shaft drives a grating (11) and an encoder (10) which are connected up and down to rotate;

and step four, detecting the pulse accumulated value of the stepping motor (1) once when the encoder (10) rotates the unit code value, and adjusting the pulse value of the stepping motor (1) when the pulse accumulated value of the stepping motor (1) is detected not to correspond to the code value when the encoder (10) is driven to detect, so that the adjusted pulse value of the stepping motor (1) is aligned to the code value of the encoder (10).

2. The device for accurately controlling the output method of the monochromator spectrum according to claim 1, wherein the device comprises a stepping motor (1), a small synchronous belt gear (2), a synchronous belt (3), a large synchronous belt gear (4), a gear bracket (5), a first rotating shaft (6), a small straight-tooth conical gear (7), a large straight-tooth cone (8), a second rotating shaft (9), an encoder (10), a grating (11) and a fixing plate (12);

the stepping motor (1) is fixed on the gear bracket (5); a rotating shaft of the stepping motor (1) penetrates through the gear bracket (5) to fix the small synchronous belt gear (2); the small synchronous belt gear (2) is meshed with the large synchronous belt gear (4) through a synchronous belt (3); the first rotating shaft (6) penetrates through the gear bracket (5) to fix the large synchronous belt gear (4) and the small straight-tooth conical gear (7); the small straight-tooth conical gear (7) is meshed with the large straight-tooth conical gear (8); the large straight-tooth conical gear (8) is fixed on the second rotating shaft (9);

the upper end of the second rotating shaft (9) is connected with the first rotating shaft (11), and the lower end of the second rotating shaft (9) is connected with the second rotating shaft (10);

the second rotating shaft (9) is arranged on the fixing part (12).