CN105823442A - Method for angle measurement through coded disc signal subdivision and photoelectric collimator - Google Patents

Abstract

To satisfy ever-increasing customer demands, aiming at the technical condition of an existing grating coded disc, the invention provides a photoelectric collimation method for angle measurement through coded disc signal subdivision. The method performs subdivision processing on photoelectric collimator grating coded disc signals, and angle subdivision is performed through simulation fitting, thereby obtaining an angle value of a measured angle. While eliminating direct current component influence, the instrument resolution ratio and precision are improved.

Description

A kind of method and photoelectronic collimating instrument being carried out angle measurement by code-disc signal subdivision

Technical field

The present invention relates to surely take aim at technical field of mapping, more particularly, to a kind of method and photoelectronic collimating instrument being carried out angle measurement by code-disc signal subdivision.

Background technology

Photoelectronic collimating instrument be possess leveling, the heart, telescope are sighted, the output of photoelectricity collimated signal, azimuth determination and angle shows with communication function in light, mechanical, electrical equipment integrally, be widely used in multiple field such as space flight, aviation.Such as, as the application in fire control system of the photoelectronic collimating instrument, in present generation aircraft avionics system, only just can give full play to the ability of equipment when fire control radar and electro-optic radar collaborative work, make avionics system overall efficiency optimal.Generally, the fire control system having fire control radar and electro-optic radar has main channel and two duties of accessory channel, and major-minor passage is automatically determined by system according to major-minor channel control logic or manually selected by pilot.Target is searched for according to each self-defining working method at search condition, fire control radar and electro-optic radar.When manually intercepting and capturing target, only intercept and capture target interested by main channel.After following the tracks of target, main channel provides Target indication for accessory channel, and same target is intercepted and captured in the servo-actuated main channel of accessory channel.Photoelectronic collimating instrument is by the analogue signal (sine wave signal) changed by optical grating Moire fringe optical signal of collection, then is processed by hardware and software thus realize angular surveying.

In the case of not using segmentation, the resolution of photoelectronic collimating instrument and the grid number of grating encoder are directly proportional, and owing to being restricted by grating scribing process level and cost of manufacture, the grid number of conventional code-disc is general all below 20,000.Therefore to improve the resolution and precision measured, the cost of lowering apparatus equipment, precision angle system typically need to take the method for segmentation.

Summary of the invention

For meeting growing customer demand, for the technical situation of existing grating encoder, the invention provides a kind of photoelectronic collimating method being carried out angle measurement by code-disc signal subdivision, including:

(1) grating encoder Moire fringe analogue signal is gathered；

(2) the grating encoder Moire fringe analogue signal collected is carried out pretreatment, and set up the relation of grating disc groove and angle；

(3) the grating encoder Moire fringe analogue signal through pretreatment is modified；

(4) the grating encoder Moire fringe analogue signal through pretreatment is carried out waveform conversion, it is thus achieved that the big number of institute's measuring angle；

(5) the grating encoder Moire fringe analogue signal through pretreatment is finely divided and revises, it is thus achieved that the decimal of institute's measuring angle；

(6) according to equation below calculating institute measuring angle θ:

θ=80 " × N+ θ_a-θ_b；

In formula: N is the periodicity of sine wave signal, and N is integer, θ_aFor the decimal of destination county deficiency complete cycle, θ_bDecimal for starting point deficiency complete cycle.

Further, described step (1) including: uses 10 bit A/D converters to be acquired analog signals.

Further, described step (2) including:

(21) from the grating encoder Moire fringe analogue signal collected, two sinusoidal signal Asin θ and Acos θ are obtained；

(22) arrange 16200 grooves on grating disc circle, then grating disc groove often moves 1 spacing, in said two sinusoidal signal just 1 cycle of change, i.e. represents angle and moves 80 ".

Further, described step (3) including:

(31) to DC component UD by carrying out being modified as follows and controlling when structure is installed at grating encoder:

A) the installation end face end jumping value of code-disc the main axis of shafting；

B) indication grating glass surface and the difference in height concordance installing anchor ring complete cycle

C) key light grid end jumping value after gluing；

D) key light grid and indication grating gap width；

(32) DC component U is calculated_DAverage:

Wherein U_D1、U_D2DC component for the grating encoder Moire fringe analogue signal that multimetering obtains；

(33) to U_SIt is modified:

U_S=Asin Φ+U_D-D。

Further, described step (4) including:

(41) said two sinusoidal signal is converted through waveform, form the cyclic pulse signal consistent with the two sinusoidal signal；

(42) described pulse signal is counted, thus obtain the big number of institute's measuring angle: 80 " × N.

Further, described step (5) including:

(51) cycle 2 π of Moire fringe analogue signal being divided into S part, S is segmentation sum；

(52) Asin θ and Acos θ is converted into digital quantity US and UC；

(53) tg θ or ctg θ are tried to achieve according to digital quantity US and UC:

$tg\mathrm{\θ}=\left|\frac{U_S}{U_C}\right|$

$ctg\mathrm{\θ}=\left|\frac{U_C}{U_S}\right|;$

(54) θ is judged according to tg θ or ctg θ_bInterval at which, and then draw θ_b；

(55) the decimal θ of destination county deficiency complete cycle is calculated_a, i.e.

θ_a=X × K

Wherein K=W/S, W are grating pitch, 0≤Φ≤2 π.

Further, described S value is the integer of 4≤S≤8.

Further, for each subdivided interval, DC component max value of error understands:

Subdivision error is maximum

The invention provides a kind of photoelectronic collimating instrument being carried out angle measurement by code-disc signal subdivision, including:

Grating encoder Moire fringe collection of simulant signal unit, is used for gathering grating encoder Moire fringe analogue signal；

Pretreatment unit, for the grating encoder Moire fringe analogue signal collected is carried out pretreatment, and sets up the relation of grating disc groove and angle；

Amending unit, for being modified the grating encoder Moire fringe analogue signal through pretreatment；

Big number computing unit, for carrying out waveform conversion to the grating encoder Moire fringe analogue signal through pretreatment, it is thus achieved that the big number of institute's measuring angle；

Decimal computing unit, for being finely divided the grating encoder Moire fringe analogue signal through pretreatment and revise, it is thus achieved that the decimal of institute's measuring angle；

Institute's measuring angle computing unit, for according to equation below calculating institute measuring angle θ:

θ=80 " × N+ θ_a-θ_b；

In formula: N is the periodicity of sine wave signal, and N is integer, θ_aFor the decimal of destination county deficiency complete cycle, θ_bDecimal for starting point deficiency complete cycle.

Further, described grating encoder Moire fringe collection of simulant signal unit is 10 bit A/D converters.

The invention have the benefit that

(1) while analyzing segmentation DC component influence, processed by numeral optimization, improve accuracy of instrument and performance, meet the growing market demand；

(2) employing is finely divided process to signal, it is possible to obtains high-resolution, can reach 0.1 "；

(3) angle measurement accuracy and precision are high；

(4) subdivision error is processed, reduce technique manufacture difficulty, save instrument cost.

Accompanying drawing explanation

Fig. 1 shows the flow chart of the photoelectronic collimating method being carried out angle measurement by code-disc signal subdivision of the present invention.

Fig. 2 shows subdivided interval scattergram；

Fig. 3 shows that angle emulates schematic diagram；

Fig. 4 shows DC component influence schematic diagram.

Detailed description of the invention

Below in conjunction with accompanying drawing, technical scheme is described.

As it is shown in figure 1, carried out the photoelectronic collimating method of angle measurement by code-disc signal subdivision, including:

(1) grating encoder Moire fringe analogue signal is gathered；

(2) the grating encoder Moire fringe analogue signal collected is carried out pretreatment, and set up the relation of grating disc groove and angle；

(3) the grating encoder Moire fringe analogue signal through pretreatment is modified；

(4) the grating encoder Moire fringe analogue signal through pretreatment is carried out waveform conversion, it is thus achieved that the big number of institute's measuring angle；

(5) the grating encoder Moire fringe analogue signal through pretreatment is finely divided and revises, it is thus achieved that the decimal of institute's measuring angle；

(6) according to equation below calculating institute measuring angle θ:

θ=80 " × N+ θ_a-θ_b；

In formula: N is the periodicity of sine wave signal, and N is integer, θ_aFor the decimal of destination county deficiency complete cycle, θ_bDecimal for starting point deficiency complete cycle.

Preferably, described step (1) including: uses 10 bit A/D converters to be acquired analog signals.

Preferably, described step (2) including:

(21) from the grating encoder Moire fringe analogue signal collected, two sinusoidal signal Asin θ and Acos θ are obtained；

(22) arrange 16200 grooves on grating disc circle, then grating disc groove often moves 1 spacing, in said two sinusoidal signal just 1 cycle of change, i.e. represents angle and moves 80 ".

Preferably, described step (3) including:

(31) to DC component UD by carrying out being modified as follows and controlling when structure is installed at grating encoder:

A) the installation end face end jumping value of code-disc the main axis of shafting；

B) indication grating glass surface and the difference in height concordance installing anchor ring complete cycle

C) key light grid end jumping value after gluing；

D) key light grid and indication grating gap width；

(32) DC component U is calculated_DAverage:

Wherein U_D1、U_D2DC component for the grating encoder Moire fringe analogue signal that multimetering obtains；

(33) to U_SIt is modified:

U_S=Asin Φ+U_D-D。

General sampled point takes 4 to 8 (every 45 ° or 90 ° samplings in full circle weeks), then brings, as instrument parameter, result of calculation of sampling into angle calculation and can eliminate the impact of DC component.

Preferably, described step (4) including:

(41) said two sinusoidal signal is converted through waveform, form the cyclic pulse signal consistent with the two sinusoidal signal；

(42) described pulse signal is counted, thus obtain the big number of institute's measuring angle: 80 " × N.

Preferably, described step (5) including:

(51) cycle 2 π of Moire fringe analogue signal being divided into S part, S is segmentation sum；

(52) Asin θ and Acos θ is converted into digital quantity US and UC；

(53) tg θ or ctg θ are tried to achieve according to digital quantity US and UC, as shown in Figure 2:

$tg\mathrm{\θ}=\left|\frac{U_S}{U_C}\right|$

$ctg\mathrm{\θ}=\left|\frac{U_C}{U_S}\right|;$

Φ is carried out 8 segmentations at 0 °～360 °, as shown in table 1 by polarity and absolute value according to digital quantity US and UC.

The interval distribution table of table 1

Interval	Φ	US	UC |	US|-|UC|	Segmentation number
						0	0 °～45 °	+	+	-	X=tg Φ
1	45 °～90 °	+	+	+	X=1+ctg Φ
						2	90 °～135 °	+	-	+	X=2+tg Φ
3	135 °～180 °	+	-	-	X=3+ctg Φ
						4	180 °～225 °	-	-	-	X=4+tg Φ
5	225 °～270 °	-	-	+	X=5+ctg Φ
						6	270 °～315 °	-	+	+	X=6+tg Φ
7	315 °～360 °	-	+	-	X=7+ctg Φ

In each interval, by MATLAB Curve fitting simulation tg Φ value and set up form, as it is shown on figure 3, according to digital quantity US and UC result of calculation thus calculate Φ angle value.

Pointing instrumentation uses 10 bit A/D converters to be acquired analog signals, every 10 " subdivided interval sets up form, and form segmentation value is 512, and angular resolution can reach 0.1 ".

(54) θ is judged according to tg θ or ctg θ_bInterval at which, and then draw θ_b；

(55) the decimal θ of destination county deficiency complete cycle is calculated_a, i.e.

θ_a=X × K

Wherein K=W/S, W are grating pitch, 0≤Φ≤2 π.

Preferably, described S value is the integer of 4≤S≤8.

Preferably, as shown in Figure 4, therefore digital subdividing requires that grating signal eliminated DC component before A/D changes, if DC component is U_D, the subdivision error that this component causes is error delta.

${\mathrm{tg\Φ}}_1=\frac{Asin\mathrm{\Φ}+U_D}{Acos\mathrm{\Φ}}$

Then

$\mathrm{\Δ}y={\mathrm{tg\Φ}}_1-tg\mathrm{\Φ}=\frac{U_D}{Acos\mathrm{\Φ}}.$

For each subdivided interval, DC component max value of error understands:

Subdivision error is maximum

The invention provides a kind of photoelectronic collimating instrument being carried out angle measurement by code-disc signal subdivision, including:

Grating encoder Moire fringe collection of simulant signal unit, is used for gathering grating encoder Moire fringe analogue signal；

Pretreatment unit, for the grating encoder Moire fringe analogue signal collected is carried out pretreatment, and sets up the relation of grating disc groove and angle；

Amending unit, for being modified the grating encoder Moire fringe analogue signal through pretreatment；

Big number computing unit, for carrying out waveform conversion to the grating encoder Moire fringe analogue signal through pretreatment, it is thus achieved that the big number of institute's measuring angle；

Decimal computing unit, for being finely divided the grating encoder Moire fringe analogue signal through pretreatment and revise, it is thus achieved that the decimal of institute's measuring angle；

Institute's measuring angle computing unit, for according to equation below calculating institute measuring angle θ:

θ=80 " × N+ θ_a-θ_b；

In formula: N is the periodicity of sine wave signal, and N is integer, θ_aFor the decimal of destination county deficiency complete cycle, θ_bDecimal for starting point deficiency complete cycle.

Preferably, described grating encoder Moire fringe collection of simulant signal unit is 10 bit A/D converters.

Although describing the present invention with reference to specific embodiment, it will be understood by those skilled in the art that and can carry out various change on the basis of without departing from the scope of the invention or carry out equivalence replacement.It addition, the content that present invention teach that can be carried out various adjustment on the basis of without departing from the scope of the invention thus adapt to specific environment or material.Therefore, the present invention should not necessarily be limited by disclosed specific embodiment, but should include all embodiments belonging to scope.

Claims (10)

1. a photoelectronic collimating method for angle measurement is carried out by code-disc signal subdivision, including:

(1) grating encoder Moire fringe analogue signal is gathered；

(2) the grating encoder Moire fringe analogue signal collected is carried out pretreatment, and set up the relation of grating disc groove and angle；

(3) the grating encoder Moire fringe analogue signal through pretreatment is modified；

(4) the grating encoder Moire fringe analogue signal through pretreatment is carried out waveform conversion, it is thus achieved that the big number of institute's measuring angle；

(5) the grating encoder Moire fringe analogue signal through pretreatment is finely divided and revises, it is thus achieved that the decimal of institute's measuring angle；

(6) according to equation below calculating institute measuring angle θ:

θ=80 " × N+ θ_a-θ_b；

In formula: N is the periodicity of sine wave signal, and N is integer, θ_aFor the decimal of destination county deficiency complete cycle, θ_bDecimal for starting point deficiency complete cycle.

Method the most according to claim 1, it is characterised in that described step (1) including: use 10 bit A/D converters that analog signals is acquired.

Method the most according to claim 1, it is characterised in that described step (2) including:

(21) from the grating encoder Moire fringe analogue signal collected, two sinusoidal signal Asin θ and Acos θ are obtained；

(22) arrange 16200 grooves on grating disc circle, then grating disc groove often moves 1 spacing, in said two sinusoidal signal just 1 cycle of change, i.e. represents angle and moves 80 ".

Method the most according to claim 1, it is characterised in that described step (3) including:

(31) to DC component U_DBy carrying out being modified as follows and controlling when structure is installed at grating encoder:

A) the installation end face end jumping value of code-disc the main axis of shafting；

B) indication grating glass surface and the difference in height concordance installing anchor ring complete cycle

C) key light grid end jumping value after gluing；

D) key light grid and indication grating gap width；

(32) DC component U is calculated_DAverage:

Wherein U_D1、U_D2DC component for the grating encoder Moire fringe analogue signal that multimetering obtains；

(33) to U_SIt is modified:

U_S=Asin Φ+U_D-D。

Method the most according to claim 1, it is characterised in that described step (4) including:

(41) said two sinusoidal signal is converted through waveform, form the cyclic pulse signal consistent with the two sinusoidal signal；

(42) described pulse signal is counted, thus obtain the big number of institute's measuring angle: 80 " × N.

Method the most according to claim 1, it is characterised in that described step (5) including:

(51) cycle 2 π of Moire fringe analogue signal being divided into S part, S is segmentation sum；

(52) Asin θ and Acos θ is converted into digital quantity US and UC；

(53) tg θ or ctg θ are tried to achieve according to digital quantity US and UC:

$tg\mathrm{\θ}=\left|\frac{U_S}{U_C}\right|$

$ctg\mathrm{\θ}=\left|\frac{U_C}{U_S}\right|;$

(54) θ is judged according to tg θ or ctg θ_bInterval at which, and then draw θ_b；

(55) the decimal θ of destination county deficiency complete cycle is calculated_a, i.e.

θ_a=X × K

Wherein K=W/S, W are grating pitch, 0≤Φ≤2 π.

Method the most according to claim 6, it is characterised in that described S value is the integer of 4≤S≤8.

Method the most according to claim 4, it is characterised in that for each subdivided interval, DC component max value of error understands:

Subdivision error is maximum

9. the photoelectronic collimating instrument being carried out angle measurement by code-disc signal subdivision, it is characterised in that including:

Grating encoder Moire fringe collection of simulant signal unit, is used for gathering grating encoder Moire fringe analogue signal；

Pretreatment unit, for the grating encoder Moire fringe analogue signal collected is carried out pretreatment, and sets up the relation of grating disc groove and angle；

Amending unit, for being modified the grating encoder Moire fringe analogue signal through pretreatment；

Big number computing unit, for carrying out waveform conversion to the grating encoder Moire fringe analogue signal through pretreatment, it is thus achieved that the big number of institute's measuring angle；

Decimal computing unit, for being finely divided the grating encoder Moire fringe analogue signal through pretreatment and revise, it is thus achieved that the decimal of institute's measuring angle；

Institute's measuring angle computing unit, for according to equation below calculating institute measuring angle θ:

θ=80 " × N+ θ_a-θ_b；

In formula: N is the periodicity of sine wave signal, and N is integer, θ_aFor the decimal of destination county deficiency complete cycle, θ_bDecimal for starting point deficiency complete cycle.

Method the most according to claim 9, it is characterised in that described grating encoder Moire fringe collection of simulant signal unit is 10 bit A/D converters.