CN107497864B - A strip tracking method suitable for thickness control in high-speed strip rolling process - Google Patents

Abstract

The present invention proposes a kind of Strip tracking suitable for high speed plate strip rolling process thickness control, this method: the distance of calibrator measurement point to the downstream rack center line of high speed board rolling is modified, obtain revised total tracking range, revised total tracking range is divided into the tracking section of n fixed length, and calculates revised tracking segment length；The average value for tracking Thickness sensitivity value in segment length at one by the Strip of calibrator, i.e. tracking section thickness value are calculated, using tracking section thickness value as tracking object；Open up the register for storing each tracking section thickness average value；Shifting function is carried out to register according to tracking section remainder and revised Strip tracking range；The data for exporting minimum offset address bit register, as track to the thickness value of the Strip at downstream rack roll gap.The present invention compensates in each tracking section since tracking remainder and execution period occupy the adverse effect to tracking accuracy, increases substantially Strip tracking accuracy.

Description

A kind of Strip tracking suitable for high speed plate strip rolling process thickness control

Technical field

The invention belongs to board rolling automatic control technology fields, and in particular to one kind is suitable for high speed plate strip rolling process The Strip tracking of thickness control.

Background technique

In plate strip rolling process, a kind of most common method for controlling thickness is by the calibrator before and after rack to strip Actual (real) thickness measure, and in turn by adjust respective execution mechanisms come to strip thickness carry out feedforward or feedback control, Due to the limitation of rolling mill structure, the maintenance of calibrator, and the band damage calibrator that breaks in order to prevent, calibrator be typically mounted at from The farther away place of roll gap of thickness change is directly generated, e.g., the entrance side calibrator of 1450mm cold continuous rolling requires installation site It disembarks frame center line about 2.5m~3.5m or so, the actual (real) thickness value and influence that this mounting means causes calibrator detected The roll gap actual value of thickness was occurred within the same time, this just needs to track Strip, to confirm it by surveying At the time of reaching calibrator measured place at the time of thick instrument measured place reaches at roll gap or by roll gap.The accuracy of Strip tracking Directly influence the thickness control effect of product.For example, feed forward type AGC (Automatic Gage Control) is for rack The spike thickness deviation that entrance side calibrator detects is eliminated, if Strip tracking inaccuracy, will result directly in shadow The roll gap position for ringing thickness is mismatched with corresponding spike thickness deviation measurement point, and original thickness deviation is caused to be put instead Greatly；Monitor-type AGC is then that the tendency thickness deviation detected for rack outlet side calibrator is eliminated, if Strip Tracking inaccuracy, will lead to the pure delay time mismatch that model calculates in closed loop feedback, then reduce the performance of Monitor Process.

The Strip following function of Modern High-Speed rolling line largely passes through as gauge automatic control function High performance programmable controller realizes, with the promotion to mill speed and the requirement of Product Precision, the controller of use Performance is also higher and higher.By taking certain 1450mm tandem mills as an example, in the tinning substrate of rolling very narrow thickness specification 0.18mm When, last rack outlet strip speed uses the SIMATIC of Siemens Company up to 1200m/min or more, thickness control system TDC (Technology and Drive Control) Series Controller, the controller most execute the period up to 1ms fastly.So And the calculating process of any controller is not totally continuous in the time, but based on the discrete calculation for executing the period, this will It is consistent with tracking length that the band tracking range for causing controller to calculate is difficult to " lucky ".For example, currently passing through the band of calibrator It is constant that material speed remains 18m/s, and it is 1ms that controller, which executes the period, and tracking length is 150mm, have passed through 8 execution periods Afterwards, the band tracking range that controller calculates is 144mm, and not up to tracks length, but using an execution period, band Tracking range is 162mm, then has been more than tracking length, and controller thinks that tracking is completed at this time, but produces the remainder of 12mm, With the extension of band tracking range and the increase of mill speed, which also will be increasing.In addition, calibrator is as biography There is the intrinsic response time in sensor and corresponding thickness control executing agency, calibrator generally between 10ms~30ms, Generally between 30ms~100ms, the response time is unobvious to the influence of tracking accuracy in low speed rolling for executing agency, but With the increase of mill speed, influence will be increasingly severe, for example, when mill speed is 1200m/min, the response time The tracking error of 800mm can at least be caused.By into current Strip tracking, the considerations of interfering above-mentioned factor, is equal Deficiency causes many product thickness deviations as caused by tracking inaccuracy especially in high-speed rolling.This is also many cold In the thickness control system of tandem rolling, the reason of feed forward type AGC is only applied to the 1st relatively low or 2 rack of rolling mill speed.

Summary of the invention

In view of the deficiencies of the prior art, the present invention proposes a kind of strip suitable for high speed plate strip rolling process thickness control Material tracking.

A kind of Strip tracking suitable for high speed plate strip rolling process thickness control, comprising the following steps:

Step 1: obtaining the response time T of calibrator_gWith the response time T of thickness control system executing agency_a, according to working as Preceding mill speed will be converted into band length the response time, to the calibrator measurement point of high speed board rolling to downstream rack center The distance l of line_sIt is modified, obtains revised total tracking range l_{S, cor}, by revised total tracking range l_{S, cor}It is divided into n The tracking section of a fixed length, and calculate revised tracking segment length l_unt；

Revised total tracking range l_{S, cor}Calculation formula it is as follows:

l_{S, cor}=l_s-V_a(T_g+T_a)；

Wherein, l_sFor calibrator measurement point to the distance of downstream rack center line, V_aFor the actual speed of current Strip.

Step 2: calculating the Strip by calibrator in a tracking segment length l_untThe average value of interior Thickness sensitivity value, Track section thickness value h_tra, section thickness value h will be tracked_traAs tracking object；

Step 3: opening up the register for storing each tracking section thickness average value: according to tracking section number n in thickness control The buffer area that register group number is n, length is 4 × nbyte is opened up in device processed, each register is according to its offset in the buffer area Address reduces direction and corresponds with the tracking section along rolling direction；

Step 4: shifting function is carried out to register according to tracking section remainder and revised Strip tracking range；

It is described that the specific of shifting function is carried out to register according to tracking section remainder and revised Strip tracking range Process is as follows:

According to the actual speed V of current Strip_aRemainder l is tracked with the preceding paragraph_rem(i-1) Strip tracking range is calculated l_{Tra, cor}(i), as Strip tracking range l_{Tra, cor}(i) it is greater than or equal to revised tracking segment length l_untWhen, it will be current The thickness value of each register memory storage is successively primary from high offset address to adjacent low offset address displacement in buffer area, This section tracking remainder l is calculated simultaneously_rem(i), and by the tracking section thickness value h of latest computed_traFormer storing data is stored in be moved The register for the highest offset address position walked resets tracking range l after the shifting function of register_{Tra, cor}(i)；

The actual speed V of the current Strip of basis_aRemainder l is tracked with the preceding paragraph_rem(i-1) Strip tracking is calculated Distance l_{Tra, cor}(i) calculation formula is as follows:

Wherein, l_{Tra, cor}(i) Strip tracking range when being shifted for tracking section i-th, T_mWeek is executed for gage controller Phase, l_rem(i-1) remainder is tracked for tracking section i-1；

The tracking section i-1 tracks remainder l_rem(i-1) calculation formula is as follows:

Wherein, l_{Tra, cor}(i-1) to track (i-1)-th displacement of section Strip tracking range when.

Step 5: exporting the data of minimum offset address bit register, as track to the Strip at downstream rack roll gap Thickness value.

Beneficial effects of the present invention:

The present invention proposes a kind of Strip tracking suitable for high speed plate strip rolling process thickness control, root of the present invention Tracking range is modified according to sensor and executing agency's response time, and is compensated in each tracking section due to tracking remainder And adverse effect of the period occupancy to tracking accuracy is executed, Strip tracking accuracy is increased substantially, Strip is helped to improve The thickness and precision of product；The present invention does not need transformation rolling line equipment and instrument arrangement simultaneously has without the investment in cost It is able to achieve, can be widely popularized in band mill on the rolling line of thickness control function.

Detailed description of the invention

Fig. 1 is the Strip track side for being suitable for high speed plate strip rolling process thickness control in the specific embodiment of the invention Method flow chart；

Fig. 2 is that tracking section divides schematic diagram in the specific embodiment of the invention；

Fig. 3 is the schematic diagram for carrying out shifting function in the specific embodiment of the invention to the register of gage controller.

Specific embodiment

The specific embodiment of the invention is described in detail with reference to the accompanying drawing.

In the present embodiment, certain five Stands Cold Tandem Mill group automatic gauge control system of 1450mm is using Siemens company SIMATIC TDC (Technology and Drive Control) controller, the execution cycle T of gage controller_mIt is set as 1ms；Be provided with calibrator before 5# rack, be Thermo Fisher company X-ray formula calibrator, producer provide response when Between T_gFor 10ms, measurement point and 5# frame central line distance l_sFor 3.15m；5# rack thickness control system is with the main biography of milling train Dynamic system is executing agency, and field-responsive test obtains the response time T of main transmission_aFor 50ms；Milling train maximum rolling Speed is 1350m/min；Rolling steel grade is MRT4, and finished product thickness 0.18mm, 5# rack reduction ratio is set as 25%, exports band Material speed is set as maximum mill speed 1350m/min, in stable state constant speed rolling, by the band speed of calibrator before 5# rack Spend V_aFor 1011~1015m/min (average speed 1013m/min, i.e. 16.88mm/ms).

A kind of Strip tracking suitable for high speed plate strip rolling process thickness control, as shown in Figure 1, including following Step:

Step 1: obtaining the response time T of calibrator_gWith the response time T of thickness control system executing agency_a, according to working as Preceding mill speed will be converted into band length the response time, to the calibrator measurement point of high speed board rolling to downstream rack center The distance l of line_sIt is modified, obtains revised total tracking range l_{S, cor}, by revised total tracking range l_{S, cor}It is divided into n The tracking section of a fixed length, and calculate revised tracking segment length l_unt。

In present embodiment, calibrator detection thickness of strip is translated into electric signal again and is sent to controller needs centainly Time, which is referred to as the response time of calibrator, and equally, thickness control system executing agency receives controller transmission Control command be adjusted in place be also required to the regular hour again, which is referred to as the response time of executing agency.In general, The response time is definite value, and the response time of calibrator is provided by producer, and the response time of executing agency can be surveyed by response The methods of examination obtains.It needs to compensate the response time during Strip tracking, to guarantee the standard of thickness control position True property.

Major part tracking is that will track time shortening to compensate the response time at present, this will be unable to adapt to rolling speed Degree variation influences tracking time bring.Therefore, band length is converted according to current mill speed by the response time, and The partial-length is subtracted on total tracking range, when compensating calibrator response time and the response of thickness control system executing agency Between on tracking generate hysteresis quality influence.

Revised total tracking range l_{S, cor}Calculation formula such as formula (1) shown in:

l_{S, cor}=l_s-V_a(T_g+T_a) (1)

Wherein, l_sFor calibrator measurement point to the distance of downstream rack center line, unit m, V_aFor the reality of current Strip Border speed, unit m/s.

In present embodiment, thickness control system executing agency can be rack transmission system or be hydraulic roll gap control system System.

It is rack main transmission in the present embodiment when thickness control system executing agency is rack main transmission, l_{S, cor}As shown in formula (2).

l_{S, cor}=l_s-V_a(T_g+T_a)=3150-16.88 × (10+50)=2137.2mm (2)

Wherein, T_aFor the response time of thickness control system executing agency, unit ms.

In present embodiment, in high speed plate strip rolling process, as shown in Fig. 2, the installation site of calibrator is apart from downstream The distance of frame central line is fixed and invariable, but is according to actually rolling in the thickness measured signal number apart from interior generation Speed processed and change.By taking certain 1450mm tandem mills thickness control system as an example, the thickness that controller receives calibrator is real Survey signal period be 1ms, 5^#The distance of calibrator measurement point to downstream rack center line is 2.5m before rack, when 5^#Rack enters When mouth mill speed is 1100m/min, only about need to track 136 thickness measured signals, but when 5^#Rack entrance rolling speed When degree drops to 100m/min, 1497 thickness measured signals of tracking are taken around, this needs to waste controller and largely stores Space.Therefore, the method is by the way of dividing the band tracking section of fixed length, according to calibrator measurement point to downstream rack center Band is divided into the tracking section of n fixed length by the distance of line, and the thickness measured value tracked in section is averaged as tracking section Thickness value, track number of segment n value it is too small, make track section it is too long, will affect thickness measure precision, n value after being averaged It should not be too large, need to guarantee that track segment length is all larger than what band in controller one execution period passed through under any mill speed Length.

In present embodiment, total tracking range is divided into 16 sections by setting tracking number of segment n=16.

Revised tracking segment length l_untFormula such as formula (3) shown in:

The length about 133.6mm of every section of tracking section, because length is very short, thickness will not occur to become on a large scale within this range Change, will not influence thickness measure precision after being averaged；When strip speed be maximum speed 1015m/min when, by each with Track Duan Yuexu 8ms executes period 1ms much larger than controller, therefore the tracking number of segment n value is reasonable.

Step 2: calculating the Strip by calibrator in a tracking segment length l_untThe average value of interior Thickness sensitivity value, Track section thickness value h_tra, section thickness value h will be tracked_traAs tracking object.

In the present embodiment, revised tracking segment length l_untFor 133.6mm, the actual speed V of current Strip_aFor 16.88mm/ms, the then measurement that calibrator completes a tracking segment length need about 8ms, the execution cycle T of gage controller_m For 1ms, then it is 8 that gage controller, which tracks the thickness value number that segment length internal feedback number is sampling at one, specific sampled value As shown in table 1.

Calibrator thickness sampled value in 1 one, table tracking segment length

The thickness average value h in a tracking segment length is calculated after sampling_traFor 0.242mm, as shown in formula (4):

In present embodiment, h_{Act, 1}For first Thickness sensitivity value of calibrator, h_{Act, 2}For second thickness of calibrator Detected value, h_{Act, j}The last one Thickness sensitivity value of calibrator within the scope of segment length is tracked for one, j is a tracking segment length The Times of Feedback of interior calibrator, numerical value are the h of 0.242mm_traFor tracking object.

Step 3: opening up the register for storing each tracking section thickness average value: according to tracking section number n in thickness control The buffer area that register group number is n, length is 4 × nbyte is opened up in device processed, each register is according to its offset in the buffer area Address reduces direction and corresponds with the tracking section along rolling direction.

In present embodiment, buffer area being opened up in gage controller and is used as register, buffer area need to store 16 groups Floating number, respectively corresponds register 1~16, and buffer area byte length is 4 × 16=64byte.It deposits highest offset address position Device 1 stores the thickness value for being located at tracking section 1, and so on, the register n storage of minimum offset address is located at the thickness of tracking section n Angle value.

Step 4: shifting function is carried out to register according to tracking section remainder and revised Strip tracking range.

In present embodiment, displacement behaviour is carried out to register according to tracking section remainder and revised Strip tracking range The detailed process of work, as shown in Figure 3.

According to the actual speed V of current Strip_aRemainder l is tracked with the preceding paragraph_rem(i-1) Strip tracking range is calculated l_{Tra, cor}(i), as Strip tracking range l_{Tra, cor}(i) it is greater than or equal to revised tracking segment length l_untWhen, it will be current The thickness value of each register memory storage is successively primary from high offset address to adjacent low offset address displacement in buffer area, This section tracking remainder l is calculated simultaneously_rem(i), and by the tracking section thickness value h of latest computed_traFormer storing data is stored in be moved The register for the highest offset address position walked resets tracking range l after the shifting function of register_{Tra, cor}(i)。

The actual speed V of the current Strip of basis_aRemainder l is tracked with the preceding paragraph_rem(i-1) Strip tracking is calculated Distance l_{Tra, cor}(i) shown in calculation formula such as formula (5):

Wherein, l_{Tra, cor}(i) Strip tracking range when being shifted for tracking section i-th, T_mWeek is executed for gage controller Phase, l_rem(i-1) remainder is tracked for tracking section i-1.

The tracking section i-1 tracks remainder l_rem(i-1) shown in calculation formula such as formula (6):

Wherein, l_{Tra, cor}(i-1) to track (i-1)-th displacement of section Strip tracking range when.

Numerical value is the thickness value of 0.242mm, is shifted by 16 times, the 1st displacement posting for deposit highest offset address position The 1, the 2nd~15 shifting function of storage is that it is primary to the low offset address position deposit closed on, and last time tracking operation is will It is stored in minimum offset address position (0~4byte) register 16.

The band tracking range calculated value l of 1st displacement_{Tra, cor}(1) as shown in formula (7):

Tracking remainder l after 1st displacement_rem(1) as shown in formula (8):

L at this time_{Tra, cor}(1) > l_unt, controller carries out the 1st shifting function, i.e., by thickness value 0.242mm deposit deposit Device 1, while resetting l_{Tra, cor}(1).The tracking process passes through 7 execution periods, in addition executing 1 execution that shifting function occupies Period, tracking time are 8ms.

The band tracking range calculated value l of 2nd displacement_{Tra, cor}(2) as shown in formula (9):

Tracking remainder l after 2nd displacement_rem(2) as shown in formula (10):

L at this time_{Tra, cor}(2) > l_unt, controller carries out the 2nd shifting function, i.e., by thickness value 0.242mm by register 1 Register 2 is read and is stored in, numerical value is substituted by the tracking section thickness average value of latest computed in former register 1, is reset simultaneously l_{Tra, cor}(2).The tracking process passes through 7 executions periods, in addition 1 execution period of shifting function occupancy is executed, when tracking Between be 8ms.

The band tracking range calculated value l of 3rd displacement_{Tra, cor}(3) as shown in formula (11):

Tracking remainder l after 3rd displacement_rem(3) as shown in formula (12):

L at this time_{Tra, cor}(3) > l_unt, controller carries out the 3rd shifting function, i.e., by thickness value 0.242mm by register 2 Register 3 is read and is stored in, numerical value is by upstream tracking section thickness value substitution in former register 2, while resetting l_{Tra, cor}(3).It should Tracking process passes through 7 execution periods, in addition executing 1 execution period that shifting function occupies, the tracking time is 8ms.

4th~15 displacement:

Strip tracking range calculated value and track the calculation of remainder and tracking and 3 times shifts phase at mode of operation Together, it repeats no more, process data is specifically as shown in table 2.

The 4th~15 secondary tracking operating process data of table 2

The band tracking range calculated value l of 16th displacement_{Tra, cor}(16) as shown in formula (13):

Tracking remainder l after 16th displacement_rem(16) as shown in formula (14):

L at this time_{Tra, cor}(16) > l_unt, controller carries out the 16th shifting function, by thickness value 0.242mm deposit deposit Device 16, while resetting l_{Tra, cor}(16), l_rem(16) the 16th displacement meter of upstream tracking section thickness value is participated in as tracking remainder It calculates.The tracking process passes through 7 execution periods, in addition executing 1 execution period that shifting function occupies, the tracking time is 8ms.

Step 5: exporting the data of minimum offset address bit register, as track to the Strip at downstream rack roll gap Thickness value.

In present embodiment, the thickness value 0.242mm read by register 16 is exported.

The tracking time of thickness value 0.242mm is 127ms, strip speed 16.88mm/ms altogether, then Strip tracks Distance should be 2143.76mm, subtract the tracking remainder 6.88mm of the 16th secondary tracking, in addition uncompensation distance 1012.8mm, then for 3149.68mm.With measurement point and 5^#The distance l of rack rolling centerline_sDeviation between=3150mm is less than 0.5mm.

Claims (2)

1. a sheet and strip tracking method suitable for high-speed strip rolling process thickness control, is characterized in that, comprises the following steps: Step 1: Obtain the response time T _g of the thickness gauge and the response time _Ta of the actuator of the thickness control system, convert the response time into the strip length according to the current rolling speed, and measure the thickness gauge measuring points for high-speed strip rolling Correct the distance l _s to the center line of the downstream frame to obtain the corrected total tracking distance l _{s, cor} , divide the corrected total tracking distance l _{s, cor} into n fixed-length tracking segments, and calculate the corrected total tracking distance the length of the trace segment l _unt ; Step 2: Calculate the average value of the thickness detection value of the sheet and strip passing through the thickness gauge within a tracking section length l _unt , that is, the tracking section thickness value h _tra , and use the tracking section thickness value h _tra as the tracking object; Step 3: Open up a register for storing the average thickness of each tracking segment: According to the number of tracking segments n, a buffer area with n register groups and a length of 4×nbyte is opened in the thickness controller, and each register in the buffer area is One-to-one correspondence with the tracking segment along the rolling direction according to its offset address decreasing direction; Step 4: Shift the register according to the remainder of the tracking segment and the corrected tracking distance of the plate and strip. The specific process is as follows: Calculate the plate and strip tracking distance l _{tra, cor} (i) according to the actual speed V _a of the current plate and strip and the tracking remainder l _rem (i-1) of the previous segment, when the plate and strip tracking distance l _{tra, cor} (i) When it is greater than or equal to the corrected length of the trace segment, l _unt , shift the thickness value currently stored in each register in the buffer from the high offset address to the adjacent low offset address, and calculate the trace of the segment at the same time. Remainder l _rem (i), and store the newly calculated trace segment thickness h _tra into the register of the highest offset address bit where the original storage data has been removed, and clear the tracking distance l _{tra after the shift operation of the register is completed, cor} (i); The calculation formula for calculating the tracking distance l _{tra, cor} (i) of the plate and strip according to the actual speed V _a of the current plate and strip and the tracking remainder l _rem (i-1) of the previous segment is as follows: Among them, l _{tra, cor} (i) is the tracking distance of the sheet and strip during the i-th displacement, T _m is the execution period of the thickness controller, and l _rem (i-1) is the tracking remainder of the tracking segment i-1; The calculation formula of the tracking remainder l _rem (i-1) of the tracking segment i-1 is as follows: Among them, l _{tra, cor} (i-1) is the tracking distance of the sheet and strip during the i-1th displacement; Step 5: Output the data of the lowest offset address bit register, which is the thickness value of the sheet and strip tracked to the roll gap of the downstream frame. 2. The sheet and strip tracking method suitable for high-speed strip rolling process thickness control according to claim 1, is characterized in that, the total tracking distance 1 _{s after the correction, the calculation formula of cor} is as follows: l _{s, cor} = l _s -V _a (T _g +T _a ); Among them, _ls is the distance from the measuring point of the thickness gauge to the center line of the downstream frame, and _Va is the actual speed of the current plate and strip.