CN1006328B - Billet length measuring method and embodiment - Google Patents

Abstract

The present invention relates to a method for measuring the length of a steal blank, which comprises: taking the self light of the hot steel blank as a signal source; imaging by using CCD sensitization and converting the signal into a video signal; making binaryzation processing and analogue-to-digital conversion; obtaining the steel blank physical length with high precision after processing by a microprocessor. Devices of the present invention comprise an improved CCD camera, a cable, a microprocessor, etc., and the present invention has the advantages of strong field adaptability, large measurement dynamic range, low cost, etc.

Description

Billet length measuring method and embodiment

The invention belongs to measuring technique.

Technology in Japan patented claim as a setting 142404/1981 discloses a kind of method of measuring the sheet metal width with linear array Charge Coupled Device (CCD) (Charge Coupled Device-is called for short CCD).The characteristics of this method are, by the tested sheet metal of his light source irradiation, utilize the signal source of the light of the light of its both sides of transmission or reflection thereon as measurement mechanism, and with the compensating signal source of reflection lasering beam as measurement mechanism.Although the measuring accuracy of this method is higher, still there is following shortcoming:

1. his light source of two kinds of sodium lamp and laser must be installed, the cost height;

2. can only measure the little measured object length of dynamic range, not the big online steel billet length of energy measurement dynamic range;

3. anti-water smoke of laser and metallic dust ability, the site environment of incompatibility hot rolling steel billet.

The objective of the invention is, at shortcoming of the prior art, proposing a kind of is signal source with hot rolling steel billet self light, uses CCD as the rectangular method of the survey of a signal detection device.

Another object of the present invention is to provide a kind of and can adapt to hot steel billet temperature variation, the device of the on-line measurement hot rolling steel billet length that the light that can conform again changes.

The said method of the present invention is, with hot steel billet self light as signal source; Become vision signal with the CCD photosensitive imaging and with signal transition; Vision signal is carried out " binaryzation " to be handled; Again its signal is carried out mould/number conversion; Automatically sample and data processing with microprocessor at last.

The said device of the present invention comprises CCD camera, cable, microprocessor etc., and CCD camera wherein comprises line array CCD, camera lens, driving circuit, signal processing circuit etc.Be added with a variable integration circuitry in the driving circuit, this circuit comprise two-stage cascade add synchronously counter, two-stage cascade can preset down counter, two 4 digital bit comparers, J-K flip flop, decimal system timing distributor, two R-S triggers, two with door, electronic switch etc., make CCD can export a vision signal that lower limit is constant.Be added with a follow circuit in the signal processing circuit, this circuit comprises four amplifiers, R-S trigger, emitter follower, reverser etc., makes the vision signal of CCD output be transformed into the constant vision signal of baseline level value.

Have a CCD camera at least, level is installed in roller-way one side, and its camera lens main shaft is vertical with steel billet direction of motion, is used to measure steel billet length.Because the steel billet motion time can depart from the roller-way center line, then above roller-way or oblique upper, at least one CCD camera is installed, the camera lens main shaft of this camera with transmit the roller axis normal, be used to revise the object distance of length camera.

Fig. 1 is the said device one embodiment synoptic diagram of the present invention;

Fig. 2 is the oscillogram that the vision signal of CCD output changes with the measured object light intensity.

Fig. 3 is the oscillogram that the vision signal of CCD output changes with surround lighting.

Fig. 4 is five road driving pulse phase diagrams of two-phase line array CCD.

Fig. 5 is a theory diagram embodiment illustrated in fig. 1.

Fig. 6 is the theory diagram of signal processing circuit in the said device of the present invention.

Fig. 7 is the theory diagram of driving circuit in the said device of the present invention.

Fig. 8 is a follow circuit schematic diagram in the said device of the present invention.

Fig. 9 is a variable integration schematic diagram in the said device of the present invention.

Figure 10 is the oscillogram of each monumented point in the schematic diagram shown in Figure 9.

Figure 11 is another embodiment synoptic diagram of the said device of the present invention.

With reference to Fig. 1, this embodiment is a steel billet segment length measurement mechanism, and it comprises: the CCD camera 1 that level is installed, be positioned at a side of the hot steel billet 2 of tested on-line rolling, and its camera lens main shaft is vertical with steel billet 2 direction of motion; A CCD camera 3 of vertically installing is positioned at the top of steel billet 2, and its camera lens main shaft is vertical with the axial line of transmission roller 4; Transmit cable 5 and 6; Microprocessor 7.When steel billet 2 enters the visual field of camera 3, self light sensation photoimaging of 3 pairs of steel billet 2 Widths of camera, and light signal is transformed into vision signal, vision signal is carried out " binaryzation " to be handled, again the signal after handling is carried out mould/number conversion, with the mode of serial pulses export one with figure in the corresponding digital quantity △ of CD length.When steel billet 2 enters the visual field of camera 1, self light sensation photoimaging of 1 pair of steel billet 2 length direction of camera, again with the step identical with camera 3, export one with figure in the corresponding digital quantity l of FB length.△ and l send into microprocessor 7 through transmission cable 5 and 6 respectively, and it is with △ and l storage and carry out series of computation, draws the segment length of tested steel billet.Operational formula is determined by the following relationship formula:

After the package unit Installation and Debugging finished, the camera lens main shaft of length a, camera 1 of surveying out DE shown in Fig. 1 was to the horizontal range Lo between the big cutting edge mouth 8, and with the value write memory of a and Lo.

For any one line array CCD camera, the object distance when the figure place of lens focus, CCD photosensitive unit and imaging just can be calculated the resolution ρ under this measurement object distance state after determining.

Because camera 3 is the cross direction photosensitive imagings to steel billet 2, and the height of roller-way is constant, therefore 3 measurement object distance can be considered definite value.So, establishing 3 resolution is ρ ₃, the figure place of the setting height(from bottom) according to 3, lens focus and CCD photosensitive unit can be obtained ρ ₃, and ρ ₃Be definite value.Then:

CD＝ρ ₃·△ ……（1）

CE＝CD+DE

＝ρ ₃·△+a ……（2）

As shown in Figure 1, CE is exactly the measurement object distance of camera 1.So, after microprocessor 7 calculates CE by (2) formula, can calculate the resolution under this measurement object distance state according to the figure place of the lens focus of camera 1 and CCD photosensitive unit.If this resolution is ρ ₁, and the figure place of establishing CCD photosensitive unit in the camera 1 is n ₁So, AB shown in Fig. 1 is maximum field of view's length of camera 1, is then determined by following formula:

AB＝ρ ₁·n ₁……（3）

The length FB that camera 1 is surveyed is determined by following formula:

FB＝ρ ₁·l ……（4）

As can be seen from Figure 1, the segment length L of tested steel billet is then determined by following formula:

L＝L ₀- 1/2 AB+FB

＝L ₀- 1/2 ρ ₁·n ₁+ρ ₁·l……（5）

Line array CCD of the present invention is all used the negative output martingale.When tested steel billet changes because of the temperature difference light intensity, will the vision signal lower limit of CCD output be floated; When site environment light changes, its vision signal baseline is floated.

As shown in Figure 2, the tested steel billet 2 of same length different temperatures, himself luminous intensity difference, steel billet 2 is luminous when weak, and the output signal of CCD is a waveform 9; Otherwise, be waveform 10.As select threshold level V for use _KCarry out " binaryzation " to 9 and 10 and handle, will obtain two different analog quantity L ₁And L ₂, and L ₂Greater than L ₁, its result does not possess monambiguity.

As shown in Figure 3, the tested steel billet 2 of same temperature, himself luminous intensity is constant.When a little less than the surround lighting, the output signal of CCD is a waveform 11; Otherwise, be waveform 12.Still select threshold level V for use _KWaveform 11 and 12 is carried out " binaryzation " handle, also will obtain two different analog quantity L ₃And L ₄, and L ₄Greater than L ₃, its result does not possess monambiguity yet.

Fig. 4 is five road driving pulse phase diagrams of two-phase line array CCD.Make the CCD can operate as normal, must apply as shown in the figure Φ to its respective electrode ₁, Φ ₂, Φ _R, Φ _PAnd Φ _TG(the three-phase device need increase by one road Φ to five road driving pulses again ₃Pulse).Usually Φ ₁, Φ ₂Be called time clock.Φ _RBe reset pulse, Φ _PBe integrated pulse, Φ _TGCry and shift pulse.Φ _PTime t for high level _PBe called integral time, it and Φ _TGBe low level time t _GEquate; Φ _PPeriod T _PBe called integration period, it and Φ _TGPeriod T _GEquate.Said variable integration is meant T among the present invention _PAnd T _GSimultaneously variable; Said change integral time, be meant t _PAnd t _GValue increase and decrease simultaneously.

Fig. 5 is the theory diagram of measuring motion embodiment illustrated in fig. 1.CCD camera 1 and 3 inner structure are just the same, include: camera lens 13, CCD14, driving circuit 15, signal processing circuit 16 etc.Self light of online hot rolling steel billet 2 length directions focuses on through camera lens 13, images in the photosensitive area of CCD14.CCD14 is under the effect of driving circuit 15, to signal processing circuit 16 outputting video signals.Signal processing circuit 16 is followed processing with vision signal, and change integral time according to the level value control Driver Circuit 15 of signal Lower Limit Amplitude, finally export and the digital quantity l that possesses monambiguity corresponding to microprocessor 7 with steel billet 2 imaging length.The principle of work of camera 3 is identical with camera 1, and it is finally exported a digital quantity △ who possesses monambiguity and gives microprocessor 7.Microprocessor 7 carries out computing by (5) formula, draws the segment length of steel billet 2.

Fig. 6 is the theory diagram of signal processing circuit 16 in the said device of the present invention.It comprises: follow circuit 17, " binaryzation " circuit 18, sample circuit 19, timing distribution circuit 20, mould/number conversion circuit 21 etc.Follow circuit 17 can carry out baseline to the vision signal of CCD14 output and follow processing, and according to the level value of vision signal Lower Limit Amplitude, sends pulse to driving circuit 15, changes the integration period of driving circuit 15; Because integration period changes, the corresponding change integral time of CCD14, the invariable vision signal of energy bottoming value; Follow circuit 17 is sent to the vision signal of " binaryzation " circuit 18, can not be subjected to the influence that steel billet self light intensity changes and surround lighting changes, and its lower limit is constant, the baseline level value is constant, and warp " binaryzation " circuit 18 is with V _KAfter the threshold level cutting, then obtain possessing the constant square-wave pulse of cycle of monambiguity, the width of pulse is exactly the analog quantity of tested steel billet imaging length in camera lens 13 visual fields; After sample circuit 19 is received the automatic sampling pulse that microprocessor sends, time-delay sends out pulse to timing distribution circuit 20, timing distribution circuit 20 sends gating pulse to " binaryzation " circuit 18, then " binaryzation " circuit 18 can be selected a square wave from the treated square waves that obtains, and send mould/number conversion circuit 21; Mould/number conversion circuit 21 is given microprocessor 7 in the mode of string shape pulse with digital quantity.

Fig. 7 is a driving circuit theory diagram in the said device of the present invention.As shown in the figure, divider 23 is sent in main 22 pulses that frequency is constant of shaking; Divider 23 is sent to logical circuit 24 by phase relation shown in Figure 4 and is produced Φ ₁, Φ ₂, Φ _RThree tunnel control signals of pulse are sent generation Φ to variable integration circuitry 25 _PAnd Φ _TGPulse signal; After sample circuit 18 sent sampling pulse, as there not being steel on the roll line, or steel billet temperature was lower than specialized range, and then follow circuit 17 does not send pulse to variable integration circuitry 25, constant Φ of 25 generation cycle of variable integration circuitry _PAnd Φ _TG Logical circuit 24 is sent in the two-way pulse; In specialized range, then follow circuit 17 can send pulse to variable integration circuitry 25 as the tested steel billet temperature on the roll line, whenever sends a pulse, the Φ that variable integration circuitry is exported _PAnd Φ _TGCycle shorten once; Five road signals that logical circuit 24 will be imported make up, and level shifting circuit 26 is sent in output five tunnel pulses as shown in Figure 4, through regulating the respective electrode of working point input CCD14, driven CCD 14 operate as normal.

The said follow circuit 17 of the present invention, schematic diagram as shown in Figure 8.This circuit 17 comprises: four operational amplifiers 27,28,29 and 30, reverser 31, R-S trigger 32, potentiometer W, triode BG1, capacitor C 1 and three resistance R ₁, R ₂, R ₃Represent the vision signal that CCD14 is exported with S, S connects the in-phase input end of amplifier 27; Amplifier 27 is connected into follower, and CCD14 and late-class circuit are isolated and obtain a vision signal S who follows fully with the S signal at output terminal, and with S ₁Meet triode BG ₁Base stage and the in-phase input end of amplifier 28; BG ₁With R ₁, R ₂Be connected into and penetrate a grade follower, and penetrating a grade resistance R ₂Last large bulk capacitance C in parallel ₁; Because R ₂With C ₁Integral action, BG ₁Emitter will obtain a direct current signal I, the level value of this direct current signal I is than base signal S ₁The baseline level value low 0.6 volt.I sends into the in-phase input end of amplifier 29, and amplifier 29 is connected into follower, then can export a direct current signal I ' who follows fully with I, I ' is connect the reverse input end of amplifier 28; Amplifier 28 is connected into closed loop amplifier, and its enlargement factor is β, because the level ratio vision signal S of I ' ₁The baseline level value low 0.6 volt, then to export a baseline level value perseverance be the vision signal S that 0.6 β lies prostrate to amplifier 28 ₂No matter how site environment light changes S ₂Baseline will keep motionless.But its Lower Limit Amplitude remains unsteady, and the degree of floating is β times of the S signal.For this reason, with S ₂Connect the in-phase input end of amplifier 30, and 30 reverse input end is connect the center plug of potentiometer W; 35 are connected into comparer, as long as S ₂Lower limit be lower than W center tap level value Vo, negative pulse J of amplifier 30 output then; J oppositely exports a positive pulse in the back through phase inverter 31 If the iron black spot of tested steel billet 2 surface oxidations is serious, the then more than pulse of J, so R-S trigger 32 is set, to make the output Q end of trigger 32 be high level by the forward position of just jumping of J, and draws Φ by variable integration circuitry 25 again _TGMake 32 upsets, only export a positive pulse with the Q end that guarantees at each integration period internal trigger 32; Positive pulse of integrating circuit 25 every receptions just can make CCD driving pulse Φ _PAnd Φ _TGCycle shorten once, cause the Lower Limit Amplitude of the S signal of CCD14 output to rise once, so S ₂Lower Limit Amplitude also rise once thereupon; Such periodic duty situation will be performed until S ₂Lower Limit Amplitude equal V ₀Till, this moment S ₂Cycle can not shorten again.V ₀Value how to determine, be the debugging in key.As V ₀Value too low, then amplifier 30 can not be exported negative pulse; As V ₀Value too high, then the number of times of trigger 32 output positive pulses increases, and makes CCD driving pulse Φ _PAnd Φ _TGThe number of times that shortens of cycle increase, as unconfined increase, will cause integration period less than the short period that can keep CCD device operate as normal.V ₀Value is too low or too high, all can not reach the purpose of restriction S signal Lower Limit Amplitude.Therefore, when carrying out field adjustable, in addition counter to be connected on the Q output terminal of trigger 32, the count status of establishing counter is Nx; Preset several 41 and 42 value according to down counter in main 22 the frequency of shaking, the variable integration circuitry 25 in the photosensitive unit figure place of CCD, the driving circuit, calculate the maximum times Nmax that N can allow appearance; Adjust the centre tapped value of W V ₀, as long as tested steel billet temperature in specialized range, then must satisfy lower inequality:

1≤Nx≤Nmax ……（6）

As long as satisfy (6) formula, S ₂The Lower Limit Amplitude of signal must be constantly equal to V ₀, different with steel billet Yin Wendu and self luminous power irrelevant.Follow circuit 17 finally can be to vision signal S of " binaryzation " circuit 18 outputs ₂, S ₂Feature be: the baseline level value is constant, lower limit is constantly equal to V ₀, the cycle is for the different fixed cycle of the luminous power of steel billet self.

Fig. 9 is a variable integration schematic diagram in the said device of the present invention.As shown in the figure, variable integration circuitry 25 is made of the medium-scale integration assembly, mainly comprise: J-K flip flop 33,34, two 4 in decimal system divider adds counter 35 and 36, two 4 digital bit comparers 37 and 38, two 4 can be preset down counter 39 and 40, two R-S triggers 43 and 46, two and door 44 and 45, triode BG ₂Deng.

J-K flip flop 33 is connected into T ' trigger, with decimal system divider 34 common 20 frequency dividers of forming, with the signal frequency split that divider 23 is sent here, exports a signal CP+ as the count pulse that adds counter 35, establishes CP ₊Cycle be T ₀; The dispense-pulse that divider 34 one-output terminals are exported is made as M, and the forward position of M is forever than CP ₊/ 10th T lag behind ₀Therefore, by M control and door 44,45, allow it make 43 upsets of R-S trigger again, then the Φ that exported of trigger 43 _PThe back edge of pulse and forward position are than the Φ that is exported by the R-S trigger 46 that CP controlled _TGThe forward position of pulse and edge, back lag behind 1/10th respectively, to satisfy the requirement of phase relation shown in Figure 4; Two 4 digital bit comparer 37,38 cross-over connections are in adding counter 35,36 and can presetting between the down counter 39,40, and they are all by the two-stage cascade wiring; If the signal of " A＞B " of high position 38 end output is R; If it is CP that follow circuit 17 is sent to the signal of low level down counter 39 input ends _-, its pulse number is represented with N; If several values of 41,42 that preset of down counter 39,40 are added up and are n ₀; If it is Y that sample circuit 19 mails to the sampling pulse of down counter 39 and 40 control PE ends; After establishing sampling pulse Y again and sending and recover low level, CP ₊The moment that first pulse front edge of signal arrives is t ₀, and tested steel billet is at t ₀Constantly just enter the visual field of CCD camera.The above-mentioned waveform of respectively setting monumented point as shown in figure 10.After steel billet enters the camera visual field, at first integration period T ₁In, CCD no-output, CP _-Do not produce positive transition, down counter 39 and 40 is subtrahend not, and its state value is n ₀; Receive CP when adding counter 35 and 36 ₊Count up to greater than n ₀Moment t ₁Constantly, positive transition appears in the output signal R of a comparer high position 38, makes J-K flip flop 33, decimal system divider 34, adds counter 35 and 36 " zero clearing " simultaneously; A spike only appears in R, can be at t in order to guarantee trigger 46 ₁The Φ of upset output constantly _TG, BG is set ₂, BG ₂With R ₄Be connected into switch working state, its effect is equivalent to electronic switch, as long as the spike effective value of R reaches 0.6V, the emitter of BG2 just occurs one and just jumping and make trigger 46 upsets.So far, finish from t ₀First Φ that constantly starts at _TGCycle; Periodic quantity T ₁For:

T ₁＝n ₀·T ₀……（7）

Φ _PCompare Φ _TG/ 10th T lag behind ₀, the value in its first cycle equals T ₁Because steel billet is from t ₀Constantly enter the camera visual field, so from t ₀In second integration period of starting at, CCD has signal output, if CP-is 3 pulses, be that N equals 3, the input end of down counter 39 will obtain one respectively at second, third, in the 4th integration period and just jump so, make " subtracting 1 " counting successively, and its state value will be by n ₀Become (n successively ₀-1), (n ₀-2), (n ₀-3); Count up to greater than (n respectively when adding counter 35 and 36 ₀-1), (n ₀-2), (n ₀-3) t ₂, t ₃, t ₄Constantly, just jumping appears respectively in the output terminal R of a comparer high position 38.Therefore, second and third, the value T of four integration periods ₂, T ₃, T ₄Be respectively:

T ₂＝（n ₀-1）·T ₀……（8）

T ₃＝（n ₀-2）·T ₀……（9）

T ₄＝（n ₀-3）·T ₀……（10）

From the 5th integration period of starting at, if CP _-No longer produce and just jump, then down counter will be kept (n ₀-3) count status value; So as long as when adding counter 35 and 36 every counting greater than (n ₀-3) t ₅, t ₆... t _nConstantly, once just jumping all appears in the output terminal R of a comparer high position 38.Therefore, the value of n integration period is:

T _n=T _N-1=(n ₀-3) T ₀(wherein n 〉=5) ... (11)

This shows that variable integration circuitry 25 has and changes Φ simultaneously _PAnd Φ _TGThe function in cycle, 17 1 pulses of every reception follow circuit are just with Φ _PAnd Φ _TGCycle shorten once, the amount of shortening is T ₀, when follow circuit 17 no longer when down counter 39 sends pulses, Φ _PAnd Φ _TGCycle no longer change.

Figure 11 is another embodiment synoptic diagram of the said device of the present invention.As shown in the figure, this embodiment is a steel billet total length measurement mechanism, it than embodiment illustrated in fig. 1 installed a horizontal camera 1 ', camera 3 is not vertical installation, its camera lens main shaft and perpendicular line have an angle α.Camera 3 can utilize field apparatus to make The Cloud Terrace and arbitrarily install, as long as the wide face of the tested steel billet of assurance is in the visual field and the camera lens main shaft is vertical with the axial line of roller 4.Camera 1 and 1 ' level are installed, and are positioned at steel billet one side, both camera lens main shafts all with the axis parallel of roller 4.If the resolution of camera 3 is ρ ^' ₃, the digital quantity of its output is △ ', then camera 1 and 1 ' measurement object distance C ' E ' be:

C′E′＝ρ ^′ ₃·△′+α′ ……（11）

The camera 1 and 1 ' CCD of the same model of employing and the camera lens of same focal length, the photosensitive unit number of establishing its CCD is n ^' ₁Calculate object distance C ' E ' afterwards according to (11) formula, can calculate camera 1 and 1 ' measuring object distance is resolution ρ under C ' E ' state ^' ₁, the digital quantity of establishing its output is respectively l ₁And l ₂, the distance of establishing again between camera 1 and 1 ' camera lens main shaft is L ^' ₀Derive by Fig. 1 embodiment above and to survey the method for segment length's computing formula, can draw the mathematic(al) representation of steel billet total length:

L′＝L ^′ ₀-ρ ^′ ₁（n ^′ ₁-l ₁-l ₂） ……（12）

The present invention compared with prior art has following advantage:

1. his light source need not be installed, directly utilize online hot rolling steel billet self photoimaging, saving equipment, reduce investment outlay.

2. environmental suitability is strong, shows:

Can overcome hot rolling steel billet self light intensity and change the measuring error of bringing;

Can overcome surround lighting and change the error of bringing;

Can overcome the measuring error that steel billet deflects and causes on roller-way;

CCD device sensitivity height, on-the-spot water smoke and dust do not influence measurement result.

3. shock resistance is strong, as long as tested steel billet in the field range of camera, does not then influence measuring accuracy.

4. maintenance is little, and because of CCD is the self-scanning device, burn in no surface, and the life-span is long, and is reliable.

5. precision height, dynamic range is big, and on-line measurement steel billet segment length scope embodiment illustrated in fig. 1 is 3.2m-6.2m, and maximum heat size absolute error is less than 20mm, and relative error is less than 6/1000ths.

Claims (4)

1, detect length of billets device comprises CCD camera [1], [3], cable [5], [6], microcomputer [7] etc.; CCD camera [1], [3] are connected with microcomputer [7] by cable [5], [6] respectively; CCD camera [1] or [3] comprise line array CCD [14], camera lens [13], driving circuit [15], signal processing circuit [16] etc.; Line array CCD [14] is connected with driving circuit [15], is input signal with the light signal of camera lens [13] imaging, and it exports termination signal processing circuit [16]; Signal processing circuit [16] is connected with microcomputer [7] with driving circuit [15] respectively; Feature of the present invention is, is added with variable integration circuitry [25] in the driving circuit [15], is added with follow circuit [17] in the signal processing circuit [16]; Variable integration circuitry [25] is arranged in driving circuit [15], is connected with follow circuit [17], the sample circuit [19] of divider [23], logical circuit [24] and signal processing circuit [16] of driving circuit [15] respectively; Follow circuit [17] is arranged in signal processing circuit [16], respectively with CCD[14], " binaryzation " circuit [18] of driving circuit [15], signal processing circuit [16] is connected;

2, as the said device of claim 1, it is characterized in that, variable integration circuitry (25) comprising: J-K flip flop (33), decimal system divider (34), 4 add counter (35), (36), 4 digital bit comparers (37), (38), and 4 can be preset down counter (39), (40) R-S trigger (43), (46), with door (44) (45), electronic switch etc.; J-K flip flop (33) is connected into T ' trigger, and its input end is connected with divider (23), and its output terminal is connected with the input end of decimal system divider (34); Add counter (35), (36) and be connected into the two poles of the earth utmost point connection and add counter synchronously, its input end is connected with " CO " output terminal of decimal system divider (34); Down counter (39), (40) are connected into two-stage cascade and can preset down counter, and its input end is connected with the Q output terminal of R-S trigger (32) in the follow circuit (17), and its PE control end is connected with sample circuit (19); The wiring cross-over connection is in adding between counter (35), (36) and down counter (39), (40) routinely for 4 digital bit comparers (37), (38), and its " A＞B " output terminal is connected with the control end of J-K flip flop (33), decimal system divider (34), the clear terminal that adds counter (35), (36) and electronic switch respectively; The output terminal that the S termination electronics of R-S trigger (46) closes, its R end and be connected to the Q1 output terminal that adds counter (35) again after an input end of door (44) is in parallel, its Q output terminal respectively with logical circuit (24), follow circuit (17) in R-S trigger (32) the R end and be connected with an input end of door (45); With the one-output terminal that is connected to decimal system divider (34) after another input end of door (44), (45) is in parallel again, two output terminal is connected with two input ends of R-S trigger (43) respectively; The Q output terminal of R-S trigger (43) is connected with logical circuit (24);

As the said device of claim 2, it is characterized in that 3, follow circuit (17) comprising: four amplifiers (27), (28), (29) and (30), penetrate a grade follower, R-S trigger (32), phase inverter (31) etc.; Amplifier (27) is connected into follower, and its input end is connected with the output terminal of CCD (14), and its output terminal is connected to the in-phase input end of amplifier (28) and the input end of emitter follower respectively; Amplifier (29) is connected into follower, the output terminal of its input termination emitter follower, the inverting input of its output termination amplifier (28); Amplifier (28) is connected into closed loop amplifier, and its output terminal connects the in-phase input end of amplifier (30) and the input end of " binaryzation " circuit (18) respectively; Amplifier (30) is connected into comparer, and its output terminal is connected with the input end of phase inverter (31); The output terminal of the S termination phase inverter (31) of R-S trigger (32), its R end is connected with the Q end of R-S trigger (46) in the variable integration circuitry (25), can preset the input end of down counter (39) in its Q termination variable integration circuitry (25);

4, as claim 3,4 said devices, it is characterized in that having at least a camera level to be installed in roller-way one side, its camera lens main shaft is vertical with steel billet direction of motion; Have at least a camera to be installed in roller-way top or oblique upper, its camera lens main shaft and transmission roller axis normal.

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