Dynamic speed regulation control method and system for automatic shearing of hot continuous rolling flying shear

Abstract

The invention provides a dynamic speed regulation control method and system for automatic shearing of a hot continuous rolling flying shear, and the method comprises the steps: firstly, when the flying shear receives the head and tail shearing length of a piece of strip steel set by a second stage, a first-stage machine stores and updates the set head and tail shearing length, and when the head of the strip steel is detected by front thermal detection of the flying shear, head tracking is started; when the distance of the flying shear from the starting position to the shearing position is larger than the sum of the distance from the head to the center line of the flying shear and the head cutting length, the flying shear starts head cutting; when the tail of the strip steel is detected by the flying shear front thermal detection, tail tracking is started, and when the distance from the starting position to the shearing position of the flying shear is larger than the difference between the distance from the tail to the center line of the flying shear and the tail cutting length, the flying shear starts tail cutting; in the starting process, when the speed of a slab changes, the distance between a shear point and the flying shear is updated in real time, a proportionality coefficient changing in real time is introduced according to the change of the distance, and finally calculated speed compensation is added to the set shear speed.

Description

Technical Field

[0001] The invention relates to the technical field of electrical automation control, and in particular to a dynamic speed regulation control method and system for automatic shearing of hot rolling flying shears. Background Art

[0002] During the hot rolling production process, the intermediate billet rolled out from the roughing mill usually has irregular shapes at the head and tail. If it enters the finishing mill directly, the risk of scrap steel will increase. Therefore, a flying shear must be used to shear the irregular parts of the head and tail before the strip enters the finishing mill.

[0003] Traditional flying shear control is usually based on the set cutting length. When cutting the head, the distance from the head of the strip to the center line of the flying shear is calculated. When the distance (arc length) traveled by the flying shear from the starting position of cutting the head to the cutting position is greater than the sum of the distance from the head of the strip to the center line of the flying shear and the set cutting length for cutting the head, the flying shear head is started; when cutting the tail, the distance from the tail of the strip to the center line of the flying shear is calculated. When the distance (arc length) traveled by the flying shear from the starting position of cutting the tail to the cutting position is greater than the difference between the distance from the tail of the strip to the center line of the flying shear and the set cutting length for cutting the tail, the flying shear tail cutting is started.

[0004] However, when performing tail shearing, in order to maintain the temperature of the strip at the finish rolling exit, the rolling mill sometimes dynamically adjusts the speed, resulting in the strip speed not being constant during tail shearing. When performing head shearing, the strip slips, which also leads to unstable strip speed during head shearing. At this time, if the flying shear still shears at a fixed speed, errors may occur. Therefore, it is very necessary to develop a variable speed shearing of the flying shear to improve the shearing accuracy in response to this situation.

[0005] The Chinese invention patent "A method for dynamically controlling the starting position of the head and tail shearing of hot-rolled flying shears" (application (patent number): CN201610361425.4, authorization announcement number: CN107433287B) discloses a method of controlling the detection area of ​​the head and tail positions of the strip by utilizing the finishing entrance area of ​​the hot rolling production line, combined with the setting of the strip head and tail position tracking stroke window, and adopting a method of dynamic shearing starting position switching control to achieve dynamic control of the strip starting shearing position control point. This technical solution uses the tracking stroke window method to exclude invalid data and correct the basic displacement of the strip, with the aim of ensuring that the true position of the intermediate billet in motion is obtained. However, this technical solution does not propose an effective solution for the intermediate billet that changes speed during the shearing process. Even if the true position of the intermediate billet can be obtained in real time, the accuracy of the flying shear shearing cannot be guaranteed when the moving intermediate billet changes speed in real time. Summary of the invention

[0006] In view of the defects in the prior art, the object of the present invention is to provide a dynamic speed control method and system for automatic shearing of hot rolling flying shears.

[0007] The dynamic speed control method for automatic shearing of hot rolling flying shear provided by the present invention comprises:

[0008] Step 1: When the flying shear receives the head and tail shearing length of the strip set by the process automation level 2, the basic automation level 1 machine stores and updates the set head and tail shearing length;

[0009] Step 2: When the heat inspection before the flying shear detects the strip head, the head tracking is started. When the distance from the starting position to the shearing position of the flying shear is greater than the sum of the distance from the head to the center line of the flying shear and the head cutting length, the flying shear starts the head cutting;

[0010] When the heat inspection before the flying shear detects the tail of the strip, the tail tracking is started. When the distance from the starting position to the shearing position of the flying shear is greater than the difference between the distance from the tail to the center line of the flying shear and the tail cutting length, the flying shear starts to cut the tail.

[0011] Step 3: When the slab speed changes during the startup process, the distance from the shear point to the flying shear will be updated in real time, and the real-time changing proportional coefficient will be introduced according to the change of the distance, and the speed compensation finally calculated will be added to the set shear speed;

[0012] The shorter the time from the intermediate billet shearing point to the flying shear shearing center line is than the expected time, the faster the flying shear is set, and vice versa.

[0013] Preferably, the shear calculation formula when the flying shear head is derived is:

[0014] During normal rolling, the secondary shear setting values ​​are sent down, including the cutting advance rate and cutting length;

[0015] Using C LEAD Indicates the cutting lead rate, L TOP Indicates the distance from the head of the intermediate billet to the center line of the flying shear, L H Indicates the cutting length;

[0016] When the head reaches the heat inspection before the flying shear, the strip head tracking is started, and the distance between the flying shear head knife and the shearing position is L CS1 , the acceleration of the flying shear is represented by a, and the traveling speed of the strip head itself is represented by V1;

[0017] When cutting, the flying shear needs to accelerate from 0 to the shearing speed for a certain distance, and this distance is fixed and set to L. ACC1 , calculate in real time the time required for the slab head to reach the center line of the flying shear and the time required for the flying shear to move from the starting position to the shearing position, and compare the two in real time; the specific formula is:

[0018]

[0019]

[0020]

[0021] (L TOP +L H )*C LEAD =L CS1 +L ACC1

[0022] When the left side < the right side, the flying shear starts to turn;

[0023] After the flying shear is started, the compensation speed is calculated, and the speed compensation proportional coefficient K is adjusted in real time according to the distance from the head shear point to the center line of the flying shear; the real-time speed compensation of the flying shear is determined according to the real-time speed of the flying shear, the leading rate / lag rate, and the real-time position of the flying shear. Finally, the actual speed compensation V of the flying shear head is calculated by multiplying the two. SPD COMPEN Therefore, the speed of the flying shear is set to V when it is automatically sheared. CS =C LEAD *V1+V SPD COMPEN .

[0024] Preferably, the speed compensation calculation process is as follows:

[0025] Assume that the real-time speed of the flying shear during the acceleration process is V PR , then the compensation speed calculation formula is:

[0026] C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)

[0027] The final speed compensation value is:

[0028] V SPD SPDCOMPEN =K*[C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)]*0.01

[0029] The actual shearing speed during the automatic shearing process of the flying shear is set as follows:

[0030] V CS ACTUAL =C LEAD *V1+K*[CLEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)]*0.01.

[0031] Preferably, the calculation formula for the shear tail is as follows:

[0032] During normal rolling, the secondary shear setting values ​​are sent down, including the cutting advance rate and cutting length;

[0033] Using C LAG represents the tail-cutting hysteresis rate, L TAIL Indicates the distance from the tail of the intermediate billet to the center line of the flying shear, L L Indicates the length of the cut tail;

[0034] When the tail reaches the heat inspection before the flying shear, the strip tail tracking is started, and the distance between the tail knife of the flying shear and the shearing position is L CS2 , the acceleration of the flying shear is represented by a1, and the travel speed of the strip head itself is represented by V2;

[0035] When cutting the tail, the flying shear needs to accelerate from 0 to the shearing speed for a certain distance, and this distance is fixed and set to L. ACC2 , calculate in real time the time required for the slab head to reach the center line of the flying shear and the time required for the flying shear to move from the starting position to the shearing position, and compare the two in real time; the specific formula is:

[0036]

[0037]

[0038]

[0039] (L TAIL -L L )*C LAG =L CS2 +L ACC2

[0040] When the left side < the right side, the flying shear starts to turn;

[0041] After the flying shear is started, the compensation speed is calculated, and the proportional coefficient K of the speed compensation is adjusted in real time according to the distance from the tail shear point to the center line of the flying shear; the real-time speed compensation of the flying shear is determined according to the real-time speed of the flying shear, the leading rate / lag rate, and the real-time position of the flying shear. Finally, the actual speed compensation V of the flying shear head is calculated by multiplying the two. SPD COMPEN Therefore, the speed of the flying shear is set to V when it is automatically sheared. CS =C LAG*V2+V SPD COMPEN .

[0042] Preferably, the speed compensation calculation process is as follows:

[0043] Assume that the real-time speed of the flying shear during the acceleration process is V PR1 , then the compensation speed calculation formula is:

[0044] C LAG *(L TAIL -L L )-L CS2 -(C LAG *V2-V PR1 ) 2 / (2*a1)

[0045] The final speed compensation value is:

[0046] V SPD SPDCOMPEN =K*[C LAG *(L TAIL -L L )-L CS2 -(C LAG *V2-V PR1 ) 2 / (2*a1)]*0.01

[0047] The actual shearing speed during the automatic shearing process of the flying shear is set as follows:

[0048] V CS ACTUAL =C LAG *V2+K*[C LAG *(L TAIL -L L )-L CS2 -(C LAG *V2-V PR1 ) 2 / (2*a1)]*0.01

[0049] Based on the characteristics of PLC high-speed scanning, the formula is scanned, calculated and executed every 8 to 10 ms, and the flying shear speed is adjusted according to the speed change of the strip, so that the flying shear speed matches the speed change of the strip, and finally the shearing point of the shear blade and the intermediate billet coincides and the shearing is completed.

[0050] The dynamic speed control system for automatic shearing of hot rolling flying shear provided by the present invention comprises:

[0051] Module M1: When the flying shear receives the head and tail shearing length of the strip set by the process automation level 2, the basic automation level 1 machine stores and updates the set head and tail shearing length;

[0052] Module M2: When the heat inspection before the flying shear detects the strip head, the head tracking is started. When the distance from the starting position to the shearing position of the flying shear is greater than the sum of the distance from the head to the center line of the flying shear and the head cutting length, the flying shear starts the head cutting;

[0053] When the heat inspection before the flying shear detects the tail of the strip, the tail tracking is started. When the distance from the starting position to the shearing position of the flying shear is greater than the difference between the distance from the tail to the center line of the flying shear and the tail cutting length, the flying shear starts to cut the tail.

[0054] Module M3: When the slab speed changes during the startup process, the distance from the shear point to the flying shear will be updated in real time, and the real-time changing proportional coefficient will be introduced according to the change of the distance, and the speed compensation finally calculated will be added to the set shear speed;

[0055] The shorter the time from the intermediate billet shearing point to the flying shear shearing center line is than the expected time, the faster the flying shear is set, and vice versa.

[0056] Preferably, the shear calculation formula when the flying shear head is derived is:

[0057] During normal rolling, the secondary shear setting values ​​are sent down, including the cutting advance rate and cutting length;

[0058] Using C LEAD Indicates the cutting lead rate, L TOP Indicates the distance from the head of the intermediate billet to the center line of the flying shear, L H Indicates the cutting length;

[0059] When the head reaches the heat inspection before the flying shear, the strip head tracking is started, and the distance between the flying shear head knife and the shearing position is L CS1 , the acceleration of the flying shear is represented by a, and the traveling speed of the strip head itself is represented by V1;

[0060] When cutting, the flying shear needs to accelerate from 0 to the shearing speed for a certain distance, and this distance is fixed and set to L. ACC1 , calculate in real time the time required for the slab head to reach the center line of the flying shear and the time required for the flying shear to move from the starting position to the shearing position, and compare the two in real time; the specific formula is:

[0061]

[0062]

[0063]

[0064] (L TOP +L H )*C LEAD =L CS1 +L ACC1

[0065] When the left side < the right side, the flying shear starts to turn;

[0066] After the flying shear is started, the compensation speed is calculated, and the speed compensation proportional coefficient K is adjusted in real time according to the distance from the head shear point to the center line of the flying shear; the real-time speed compensation of the flying shear is determined according to the real-time speed of the flying shear, the leading rate / lag rate, and the real-time position of the flying shear. Finally, the actual speed compensation V of the flying shear head is calculated by multiplying the two. SPD COMPEN Therefore, the speed of the flying shear is set to V when it is automatically sheared. CS =C LEAD *V1+V SPD COMPEN .

[0067] Preferably, the speed compensation calculation process is as follows:

[0068] Assume that the real-time speed of the flying shear during the acceleration process is V PR , then the compensation speed calculation formula is:

[0069] C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)

[0070] The final speed compensation value is:

[0071] V SPD SPDCOMPEN =K*[C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)]*0.01

[0072] The actual shearing speed during the automatic shearing process of the flying shear is set as follows:

[0073] V CS ACTUAL =C LEAD *V1+K*[C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)]*0.01.

[0074] Preferably, the calculation formula for the shear tail is as follows:

[0075] During normal rolling, the secondary shear setting values ​​are sent down, including the cutting advance rate and cutting length;

[0076] Using C LAG represents the tail-cutting hysteresis rate, L TAIL Indicates the distance from the tail of the intermediate billet to the center line of the flying shear, L L Indicates the length of the cut tail;

[0077] When the tail reaches the heat inspection before the flying shear, the strip tail tracking is started, and the distance between the tail knife of the flying shear and the shearing position is L CS2 , the acceleration of the flying shear is represented by a1, and the travel speed of the strip head itself is represented by V2;

[0078] When cutting the tail, the flying shear needs to accelerate from 0 to the shearing speed for a certain distance, and this distance is fixed and set to L. ACC2 , calculate in real time the time required for the slab head to reach the center line of the flying shear and the time required for the flying shear to move from the starting position to the shearing position, and compare the two in real time; the specific formula is:

[0079]

[0080]

[0081]

[0082] (L TAIL -L L )*C LAG =L CS2 +L ACC2

[0083] When the left side < the right side, the flying shear starts to turn;

[0084] After the flying shear is started, the compensation speed is calculated, and the proportional coefficient K of the speed compensation is adjusted in real time according to the distance from the tail shear point to the center line of the flying shear; the real-time speed compensation of the flying shear is determined according to the real-time speed of the flying shear, the leading rate / lag rate, and the real-time position of the flying shear. Finally, the actual speed compensation V of the flying shear head is calculated by multiplying the two. SPD COMPEN Therefore, the speed of the flying shear is set to V when it is automatically sheared. CS =C LAG *V2+V SPD COMPEN .

[0085] Preferably, the speed compensation calculation process is as follows:

[0086] Assume that the real-time speed of the flying shear during the acceleration process is V PR1 , then the compensation speed calculation formula is:

[0087] C LAG *(L TAIL -LL )-L CS2 -(C LAG *V2-V PR1 ) 2 / (2*a1)

[0088] The final speed compensation value is:

[0089] V SPD SPDCOMPEN =K*[C LAG *(L TAIL -L L )-L CS2 -(C LAG *V2-V PR1 ) 2 / (2*a1)]*0.01

[0090] The actual shearing speed during the automatic shearing process of the flying shear is set as follows:

[0091] V CS ACTUAL =C LAG *V2+K*[C LAG *(L TAIL -L L )-L CS2 -(C LAG *V2-V PR1 ) 2 / (2*a1)]*0.01

[0092] Based on the characteristics of PLC high-speed scanning, the formula is scanned, calculated and executed every 8 to 10 ms, and the flying shear speed is adjusted according to the speed change of the strip, so that the flying shear speed matches the speed change of the strip, and finally the shearing point of the shear blade and the intermediate billet coincides and the shearing is completed.

[0093] Compared with the prior art, the present invention has the following beneficial effects:

[0094] The present invention provides an automatic shearing control function for adjusting the shearing speed of the flying shear according to the speed change of the slab speed, so as to dynamically adjust the shearing speed of the flying shear when the speed of the intermediate slab changes. When the shearing point of the slab reaches the shearing position, the shearing blade of the flying shear just coincides with the shearing point for shearing. When the speed of the intermediate slab from rough rolling on the hot rolling production line fluctuates, the use of this flying shear speed change control automatic shearing technology can effectively improve the shearing accuracy, increase the yield rate, and expand the profitability of the hot rolling enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0095] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0096] Figure 1It is a flow chart of the dynamic speed control method for automatic shearing of hot rolling flying shear;

[0097] Figure 2 This is the principle block diagram of the negative feedback control system for dynamic speed regulation during the flying shear shearing process;

[0098] Figure 3 This is the layout schematic diagram of the flying shear and the equipment before and after it in the hot rolling production line; DETAILED DESCRIPTION

[0099] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0100] Example 1

[0101] The present invention provides a dynamic speed regulation control method for automatic shearing of hot rolling flying shears, comprising:

[0102] First, when the flying shear receives the head and tail shearing length of the strip set by the second level (process automation, the same meaning below), the first level (basic automation, the same meaning below) machine stores and updates the set head and tail shearing length. When the heat detection before the flying shear detects the head of the strip, the head tracking is started. When the distance from the starting position to the shearing position of the flying shear is greater than the sum of the distance from the head to the center line of the flying shear and the head cutting length, the flying shear starts the head cutting; when the heat detection before the flying shear detects the tail of the strip, the tail tracking is started. When the distance from the starting position to the shearing position of the flying shear is greater than the sum of the distance from the tail to the center line of the flying shear When the difference between the distance and the tail cutting length is greater than 0.01mm, the flying shear starts to cut the tail; when the slab speed changes during the startup process, the distance from the shearing point to the flying shear will be updated in real time, and the real-time changing proportional coefficient will be introduced according to the change of the distance, and the speed compensation finally calculated will be added to the set shearing speed. The speed control of the automatic shearing of the flying shear follows the following principles for the slab: the shorter the time from the intermediate slab shearing point (i.e. the preparatory shearing point at the head or tail when cutting the head or tail, i.e. the contact position between the blade and the intermediate slab during shearing) to the flying shear shearing center line is than the expected time, the faster the flying shear set speed will be, and vice versa.

[0103] First, the shear calculation formula for the flying shear head is derived:

[0104] 1. During normal rolling, the secondary shear setting values ​​are issued, including the cutting advance rate and cutting length;

[0105] Using C LEAD Indicates the cutting lead rate, L TOP Indicates the distance from the head of the intermediate billet to the center line of the flying shear, L H Indicates the cutting length;

[0106] 2. When the head reaches the thermal inspection before the flying shear (scanning thermal inspection is recommended, which is more stable), start the strip head tracking, and the distance between the flying shear head knife and the shearing position is L CS1 (arc length), the acceleration of the flying shear is represented by a, and the travel speed of the strip head itself is represented by V1;

[0107] 3. When cutting, the flying shear needs to accelerate from 0 to the shearing speed for a certain distance, and this distance is fixed and set to L. ACC1 , calculate in real time the time required for the slab head to reach the center line of the flying shear and the time required for the flying shear to move from the starting position to the shearing position, and compare the two in real time;

[0108] The specific formula is:

[0109]

[0110]

[0111]

[0112] (L TOP +L H )*C LEAD =L CS1 +L ACC1

[0113] When the left side < the right side, the flying shear can start the transfer;

[0114] 4. After the flying shear is started, the compensation speed is calculated. The speed compensation proportional coefficient K is adjusted in real time according to the distance from the head shear point to the center line of the flying shear. The real-time speed compensation of the flying shear is determined according to the real-time speed of the flying shear, the leading rate (lag rate) and the real-time position of the flying shear. Finally, the actual speed compensation V of the flying shear head is calculated by multiplying the two. SPD COMPEN Therefore, the speed of the flying shear is set to V when it is automatically sheared. CS =C LEAD *V1+V SPD COMPEN ;

[0115] 5. The proportional coefficient K is determined by piecewise interpolation. The specific interpolation table is as follows:

[0116] L(mm) 855 610 490 300 200 150 -20 K 0 -300 -300 -200 -5 0 0

[0117] 6. The speed compensation calculation method is as follows:

[0118] Assume that the real-time speed of the flying shear during acceleration is V PR , then the compensation speed calculation formula is:

[0119] C LEAD *(L TOP+L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)

[0120] The final speed compensation value is:

[0121] V SPD SPDCOMPEN =K*[C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)]*0.01

[0122] 7. The actual shearing speed during the automatic shearing process is set as follows:

[0123] V CS ACTUAL =C LEAD *V1+K*[C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)]*0.01

[0124] Correspondingly, the calculation formula for the shear tail is as follows:

[0125] 1. During normal rolling, the secondary shear setting values ​​are issued, including the cutting advance rate and cutting length;

[0126] Using C LAG represents the tail-cutting hysteresis rate, L TAIL Indicates the distance from the tail of the intermediate billet to the center line of the flying shear, L L Indicates the length of the cut tail;

[0127] 2. When the tail reaches the thermal inspection before the flying shear (scanning thermal inspection is recommended, which is more stable), start the strip tail tracking, and the distance between the tail knife of the flying shear and the shearing position is L CS2 (arc length), the acceleration of the flying shear is represented by a1, and the travel speed of the strip head itself is represented by V2;

[0128] 3. When cutting the tail, the flying shear needs to accelerate from 0 to the shearing speed for a certain distance, and this distance is fixed and set to L. ACC2 , calculate in real time the time required for the slab head to reach the center line of the flying shear and the time required for the flying shear to move from the starting position to the shearing position, and compare the two in real time;

[0129] The specific formula is:

[0130]

[0131]

[0132]

[0133] (L TAIL -L L )*C LAG =L CS2 +L ACC2

[0134] When the left side < the right side, the flying shear can start the transfer;

[0135] 4. After the flying shear is started, the compensation speed is calculated. The speed compensation proportional coefficient K is adjusted in real time according to the distance from the tail shear point to the center line of the flying shear. The real-time speed compensation of the flying shear is determined according to the real-time speed of the flying shear, the leading rate (lag rate) and the real-time position of the flying shear. Finally, the actual speed compensation V of the flying shear head is calculated by multiplying the two. SPD COMPEN Therefore, the speed of the flying shear is set to V when it is automatically sheared. CS =C LAG *V2+V SPD COMPEN ;

[0136] 5. The proportional coefficient K is determined by piecewise interpolation. The specific interpolation table is as follows:

[0137] L(mm) 855 610 490 300 200 150 -20 K 0 -300 -300 -200 -5 0 0

[0138] 6. The speed compensation calculation method is as follows:

[0139] Assume that the real-time speed of the flying shear during acceleration is V PR1 , then the compensation speed calculation formula is:

[0140] C LAG *(L TAIL -L L )-L CS2 -(C LAG *V2-V PR1 ) 2 / (2*a1)

[0141] The final speed compensation value is:

[0142] V SPD SPDCOMPEN =K*[C LAG *(L TAIL -L L )-L CS2 -(C LAG *V2-V PR1 )2 / (2*a1)]*0.01

[0143] 7. The actual shearing speed during the automatic shearing process is set as follows:

[0144] V CS ACTUAL =C LAG *V2+K*[C LAG *(L TAIL -L L )-L CS2 -(C LAG *V2-V PR1 ) 2 / (2*a1)]*0.01

[0145] With the help of the high-speed scanning characteristics of PLC, the formula can be scanned, calculated and executed every 8 to 10 ms. The flying shear speed can be adjusted relatively quickly according to the speed change of the strip, so that the flying shear speed matches the speed change of the strip, and finally the shearing point of the shear blade and the intermediate billet coincides and the shearing is completed.

[0146] Figure 1 This is a flow chart of the dynamic speed control method for automatic shearing of hot rolling flying shears. The shearing position of the head and tail of the strip is calculated by the set shearing amount. When the head and tail reach the shearing start position, the flying shear is started, and the flying shear speed is dynamically adjusted according to the speed of the moving slab to perform shearing.

[0147] Figure 2 This is a principle block diagram of the negative feedback control system for dynamic speed regulation during the flying shear shearing process. According to the set speed of the flying shear, the distance from the flying shear blade to the pre-calculated shearing angle and the distance from the shearing point at the head or tail of the strip to the center line of the flying shear, the compensation speed of the flying shear is dynamically calculated to ensure that when the flying shear is turned to the shearing angle, the blade and the pre-set shearing point of the strip coincide with each other;

[0148] Figure 3 This is the schematic diagram of the layout of the flying shear and the equipment before and after it in the hot rolling production line, including laser velocimeter (accurately calculates the forward position of the strip), pyrometer (real-time detection of strip temperature and setting timing), HMD 2048 (high-precision scanning heat detection, accurate tracking of strip position), descaling inlet and outlet pinch roller encoder (calculates the tail position of the strip), etc.

[0149] Example 2

[0150] Application example: The thickness of the intermediate billet is 34mm, the target length of the head shearing is 80mm, the tail shearing length is 90mm, the speed of the intermediate billet during the tail cutting process increases from 0.7m / s to 0.9m / s, and the speed of the intermediate billet during the head cutting process increases from 1m / s to 1.2m / s.

[0151] First, the verification and implementation instructions of the flying shear head are as follows:

[0152] 1. In normal rolling, the second-level setting head advance rate is 10%, the head target shearing length is set to 80mm, the flying shear head knife waiting angle is 50°, and the intermediate billet thickness is 34mm. According to the angle calculation formula, the target shearing angle can be calculated as: 165.71°;

[0153] 2. Before the flying shear is started, the pre-calculated acceleration distance is fixed, and the acceleration is set at 1.9m / s 2 , according to the formula It can be pre-calculated that the acceleration distance of the flying shear is 318.4210mm;

[0154] Among them, v t and v0 respectively represent the shear speed of the flying shear (the shear setting speed multiplied by the advance rate, both issued by the second level) and zero speed (i.e. the speed is 0 m / s);

[0155] The distance that the flying shear travels from the waiting angle to the cutting angle is: (165.71-50) / 360*3370.92=1083.46mm, so the time required for the flying shear to start cutting can be calculated as:

[0156]

[0157] Wherein, V represents the secondary preset shearing speed, which is also the slab transport speed before the flying shear head; C represents the shearing head advance rate, which is the ratio of the shear blade speed to the slab speed when the flying shear head is in operation; L ACC Indicates the distance traveled by the flying shear when accelerating from 0 to the shear speed;

[0158] Correspondingly, the distance from the tail shear point to the flying shear when the flying shear is started can be calculated as:

[0159] L=V*tL H =1.274437*1000=1274.437mm

[0160] Among them, t represents the time required for the flying shear to start cutting;

[0161] That is, when the head moves forward at a speed of 1m / s, the flying shear starts to start when the tail shearing point is 1274.437mm away from the center line of the flying shear.

[0162] 3. After the flying shear is started, it starts to move in a way of accelerating first and then uniform speed. At the same time, the intermediate billet continues to move forward at a speed of 1m / s. After 1 second, the speed of the intermediate billet begins to increase from 1m / s to 1.2m / s. At this time: the flying shear has accelerated to the shearing speed (i.e. 1.1m / s). At this time, the intermediate billet has traveled 1m, that is, the head shearing point is about 274.437mm away from the center line of the flying shear. According to the segmented interpolation table, the speed compensation coefficient can be calculated as: -150.152. At the same time, the arc length of the flying shear from the shearing point is: 765.039mm. Correspondingly, according to the speed compensation formula, the real-time compensation speed can be calculated as:

[0163] V SPD COMPEN =K*[C*LL CS1 -(VV PR ) 2 / 2a]*0.01

[0164] =-150.152*(1.1*274.437-781.579-(1100-1723.3689) 2 / (2*1900))*0.01

[0165] =566.7308mm / s

[0166] 4. According to the speed compensation of the flying shear calculated by the above formula, the corrected target shear speed of the flying shear can be calculated as:

[0167] V=C*V 中间坯 +V SPD COMPEN

[0168] =1.1*1000+566.7308

[0169] =1666.7308m / s

[0170] 5. At every moment, the flying shear is making speed compensation by comprehensively considering the change of the distance from the shear point to the flying shear and the change of the position of its own shear blade, so as to correct the flying shear speed. When the intermediate billet moves to 170mm from the target shear point at a speed of 1.2m / s, the flying shear speed compensation is:

[0171] V SPD COMPEN =K*[C*LL CS -(C LEAD *VV PR ) 2 / 2a]*0.01

[0172] =-2*(1.1*170-893.749-(1320-1842.890) 2 / (2*1900))*0.01

[0173] =12.6959mm / s

[0174] Correspondingly, the flying shear speed is:

[0175] V=C*V 中间坯 +V SPD COMPEN

[0176] =1.1*1200+12.6959

[0177] =1332.6959mm / s

[0178] 6. When the intermediate billet moves at a speed of 1.2m / s to a distance of 151mm from the target shearing point, the flying shear speed compensation is:

[0179] V SPD COMPEN =K*[C*LL CS -(C LEAD *VV PR ) 2 / 2a]*0.01

[0180] =-0.1*(1.1*151-914.85-(1.1*1200-1864.5187) 2 / (2*1900))*0.01

[0181] =0.6707mm / s

[0182] Correspondingly, the set speed of the flying shear can be calculated as:

[0183] V=C*V 中间坯 +V SPD COMPEN

[0184] =1.1*1200+0.6707

[0185] =1320.6707mm / s

[0186] 7. Finally, when the shear point at the tail of the intermediate billet reaches the predetermined shear position from 151mm away from the center line of the flying shear, the elapsed time is:

[0187]

[0188] Among them, v represents the transmission speed of the intermediate billet;

[0189] Correspondingly, the arc length of the flying shear is:

[0190] x'=L CS +V*t

[0191] =914.85+1320*0.12583

[0192] =1080.9456mm

[0193] As can be seen from Figure 2, the pre-calculated target distance that the flying shear passes when it reaches the target position is 1080.9456 mm, and the difference between the two is about 3 mm. This better achieves the goal of improving the shearing accuracy and yield rate by dynamically adjusting the flying shear speed when the intermediate billet changes speed.

[0194] Then the verification and implementation of the flying shear tail is described:

[0195] 1. In normal rolling, the tail lag rate is set to 10% in the second stage, the tail target shearing length is set to 90mm, the flying shear waiting angle is 50°, and the target shearing angle can be calculated as 165.71° according to the angle calculation formula when the intermediate billet thickness is 34mm;

[0196] 2. Before the flying shear is started, the pre-calculated acceleration distance is fixed, and the acceleration is set at 1.9m / s 2 , according to the formula The acceleration distance of the flying shear can be calculated in advance as: 104.4473mm, and the distance that the flying shear passes from the waiting angle to the shearing angle is: (165.71-50) / 360*3370.92=1083.46mm, so the time required for the flying shear from starting to shearing can be calculated in advance as:

[0197]

[0198] Correspondingly, the distance from the tail shear point to the flying shear when the flying shear is started can be calculated as:

[0199] L=V*t=1.88557*700=1319.899mm

[0200] That is, when the tail moves forward at a speed of 0.7m / s, when the tail shearing point is 1319.899mm away from the center line of the flying shear, the flying shear starts to start.

[0201] 3. After the flying shear is started, it starts to move in a way of accelerating first and then uniform speed. At the same time, the intermediate billet continues to move forward at a speed of 0.7m / s. After 1.5 seconds, the speed of the intermediate billet increases from 0.7m / s to 0.9m / s. At this time: the flying shear has accelerated to the shearing speed (i.e. 0.63m / s). At this time, the intermediate billet has traveled 1.05m, that is, the tail shearing point is about 269.899mm away from the center line of the flying shear. According to the segmented interpolation table, the speed compensation coefficient can be calculated as: -136.30305. At the same time, the arc length of the flying shear is: 840.5582mm. Correspondingly, according to the speed compensation formula, the real-time compensation speed can be calculated as:

[0202] V SPD COMPEN =K*[C*LLCS -(VV PR ) 2 / 2a]*0.01

[0203] =-136.06*(0.9*269.899-840.5582-(630-1787.210) 2 / (2*1900))*0.01

[0204] =333.6805mm / s

[0205] 4. According to the speed compensation of the flying shear calculated by the above formula, the corrected target shear speed of the flying shear can be calculated as:

[0206] V=C*V 中间坯 +V SPD COMPEN

[0207] =0.9*700+338.6805

[0208] =968.6805mm / s

[0209] 5. At every moment, the flying shear is comprehensively considering the change of the distance from the shear point to the flying shear and the change of the position of its own shear blade to compensate for the speed and correct the flying shear speed. When the intermediate billet moves to 170mm from the target shear point at a speed of 0.9m / s, the flying shear speed compensation is:

[0210] V SPD COMPEN =K*[C*LL CS -(VV PR ) 2 / 2a]*0.01

[0211] =-2*(0.9*170-929.7516-(810-1879.6425) 2 / (2*1900))*0.01

[0212] =9.513mm / s

[0213] Correspondingly, the flying shear speed is:

[0214] V=C*V 中间坯 +V SPD COMPEN

[0215] =0.9*900+9.513

[0216] =819.513mm / s

[0217] 6. When the intermediate billet moves at a speed of 0.9m / s to a distance of 151mm from the target shearing point, the flying shear speed compensation is:

[0218] V SPD COMPEN =K*[C*LL CS -(VV PR ) 2 / 2a]*0.01

[0219] =-0.1*(0.9*151-946.8516-(810-1896.850) 2 / (2*1900))*0.01

[0220] =0.5mm / s

[0221] Correspondingly, the set speed of the flying shear can be calculated as:

[0222] V=C*V 中间坯 +V SPD COMPEN

[0223] =0.9*900+0.5

[0224] =815.4956mm / s

[0225] 7. Finally, when the shear point at the tail of the intermediate billet reaches the predetermined shear position from 151mm away from the center line of the flying shear, the elapsed time is:

[0226]

[0227] Correspondingly, the arc length of the flying shear is:

[0228] x=L CS +V*t

[0229] =946.8516+810*0.168

[0230] =1082.9316mm

[0231] As can be seen from Figure 2, the pre-calculated target distance that the flying shear passes when it moves to the target position is 1083.46 mm, and the difference between the two is about 0.52 mm. This perfectly achieves the goal of improving the shearing accuracy and yield rate by dynamically adjusting the flying shear speed when the intermediate billet changes speed.

[0232] From the above calculation results, it can be found that when the speed of the intermediate billet strip changes, the flying shear will autonomously adjust the speed (accelerate or decelerate) through speed compensation. Based on the excellent transmission performance of the flying shear motor, the PLC scans and executes the speed compensation formula once every 8 to 10 ms, allowing the flying shear speed to adapt to the speed change of the intermediate billet, thereby ensuring that the shear blade and the set shear point are in the same position during shearing, thereby improving the success rate and stability of shearing.

[0233] Those skilled in the art know that, in addition to implementing the system, device and its various modules provided by the present invention in a purely computer-readable program code, it is entirely possible to implement the same program in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps. Therefore, the system, device and its various modules provided by the present invention can be considered as a hardware component, and the modules included therein for implementing various programs can also be considered as structures within the hardware component; the modules for implementing various functions can also be considered as both software programs for implementing the method and structures within the hardware component.

[0234] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A dynamic speed control method for automatic shearing of hot rolling flying shears, characterized in that: include: Step 1: When the flying shear receives the head and tail shearing length of the strip set by the process automation level 2, the basic automation level 1 machine stores and updates the set head and tail shearing length; Step 2: When the heat inspection before the flying shear detects the strip head, the head tracking is started. When the distance from the starting position to the shearing position of the flying shear is greater than the sum of the distance from the head to the center line of the flying shear and the head cutting length, the flying shear starts the head cutting; When the heat inspection before the flying shear detects the tail of the strip, the tail tracking is started. When the distance from the starting position to the shearing position of the flying shear is greater than the difference between the distance from the tail to the center line of the flying shear and the tail cutting length, the flying shear starts to cut the tail. Step 3: When the slab speed changes during the startup process, the distance from the shear point to the flying shear will be updated in real time, and the real-time changing proportional coefficient will be introduced according to the change of the distance, and the speed compensation finally calculated will be added to the set shear speed; The shorter the time from the intermediate billet shearing point to the flying shear shearing center line is than the expected time, the faster the flying shear is set, and vice versa.

2. The dynamic speed control method for automatic shearing of hot rolling flying shear according to claim 1 is characterized in that: Derivation of the shear calculation formula when flying shear head: During normal rolling, the secondary shear setting values ​​are sent down, including the cutting advance rate and cutting length; Using C LEAD Indicates the cutting lead rate, L TOP Indicates the distance from the head of the intermediate billet to the center line of the flying shear, L H Indicates the cutting length; When the head reaches the heat inspection before the flying shear, the strip head tracking is started, and the distance between the flying shear head knife and the shearing position is L CS1 , the acceleration of the flying shear is represented by a, and the traveling speed of the strip head itself is represented by V1; When cutting, the flying shear needs to accelerate from 0 to the shearing speed for a certain distance, and this distance is fixed and set to L. ACC1 , calculate in real time the time required for the slab head to reach the center line of the flying shear and the time required for the flying shear to move from the starting position to the shearing position, and compare the two in real time; the specific formula is: (L TOP +L H )*C LEAD =L CS1 +L ACC1 When the left side is smaller than the right side, the flying shear starts to turn; After the flying shear is started, the compensation speed is calculated, and the speed compensation proportional coefficient K is adjusted in real time according to the distance from the head shear point to the center line of the flying shear; the real-time speed compensation of the flying shear is determined according to the real-time speed of the flying shear, the leading rate / lag rate, and the real-time position of the flying shear. Finally, the actual speed compensation V of the flying shear head is calculated by multiplying the two. SPD COMPEN Therefore, the speed of the flying shear is set to V when it is automatically sheared. CS =C LEAD *V1+V SPD COMPEN .

3. The dynamic speed control method for automatic shearing of hot rolling flying shear according to claim 2 is characterized in that: The speed compensation calculation process is as follows: Assume that the real-time speed of the flying shear during the acceleration process is V PR , then the compensation speed calculation formula is: C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a) The final speed compensation value is: V SPD SPDCOMPEN =K*[C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)]*0.01 The actual shearing speed during the automatic shearing process of the flying shear is set as follows: V CS ACTUAL =C LEAD *V1+K*[C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)]*0.01。 4. The dynamic speed control method for automatic shearing of hot rolling flying shear according to claim 3 is characterized in that: The calculation formula for the shear tail is as follows: During normal rolling, the secondary shear setting values ​​are sent down, including the cutting advance rate and cutting length; Using C LAG represents the tail-cutting hysteresis rate, L TAIL Indicates the distance from the tail of the intermediate billet to the center line of the flying shear, L L Indicates the tail cutting length; When the tail reaches the heat inspection before the flying shear, the strip tail tracking is started, and the distance between the tail knife of the flying shear and the shearing position is L CS2 , the acceleration of the flying shear is represented by a1, and the travel speed of the strip head itself is represented by V2; When cutting the tail, the flying shear needs to accelerate from 0 to the shearing speed for a certain distance, and this distance is fixed and set to L. ACC2 , calculate in real time the time required for the slab head to reach the center line of the flying shear and the time required for the flying shear to move from the starting position to the shearing position, and compare the two in real time; the specific formula is: (L TAIL -L L )*C LAG =L CS2 +L ACC2 When the left side is smaller than the right side, the flying shear starts to turn; After the flying shear is started, the compensation speed is calculated, and the proportional coefficient K of the speed compensation is adjusted in real time according to the distance from the tail shear point to the center line of the flying shear; the real-time speed compensation of the flying shear is determined according to the real-time speed of the flying shear, the leading rate / lag rate, and the real-time position of the flying shear. Finally, the actual speed compensation V of the flying shear head is calculated by multiplying the two. SPD COMPEN Therefore, the speed of the flying shear is set to V when it is automatically sheared. CS =C LAG *V2+V SPD COMPEN .

5. The dynamic speed control method for automatic shearing of hot rolling flying shear according to claim 4 is characterized in that: The speed compensation calculation process is as follows: Assume that the real-time speed of the flying shear during the acceleration process is V PR1 , then the compensation speed calculation formula is: <h2 style=";text-align:left;direction:ltr">C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *(L<h2 style=";text-align:left;direction:ltr"> TAIL <h2 style=";text-align:left;direction:ltr"> -L<h2 style=";text-align:left;direction:ltr"> L <h2 style=";text-align:left;direction:ltr"> )-L<h2 style=";text-align:left;direction:ltr"> CS2 <h2 style=";text-align:left;direction:ltr"> -(C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *V2-V<h2 style=";text-align:left;direction:ltr"> PR1 <h2 style=";text-align:left;direction:ltr"> )<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> / (2*a1) The final speed compensation value is: <h2 style=";text-align:left;direction:ltr">V<h2 style=";text-align:left;direction:ltr"> SPD SPDCOMPEN <h2 style=";text-align:left;direction:ltr"> (K*[C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *(L<h2 style=";text-align:left;direction:ltr"> TAIL <h2 style=";text-align:left;direction:ltr"> -L<h2 style=";text-align:left;direction:ltr"> L <h2 style=";text-align:left;direction:ltr"> )-L<h2 style=";text-align:left;direction:ltr"> CS2 <h2 style=";text-align:left;direction:ltr"> -(C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *V2-V<h2 style=";text-align:left;direction:ltr"> PR1 <h2 style=";text-align:left;direction:ltr"> )<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> / (2*a1)]*0.01 The actual shearing speed during the automatic shearing process of the flying shear is set as follows: <h2 style=";text-align:left;direction:ltr">V<h2 style=";text-align:left;direction:ltr"> CS ACTUAL <h2 style=";text-align:left;direction:ltr"> =C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *V2+K*[C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *(L<h2 style=";text-align:left;direction:ltr"> TAIL <h2 style=";text-align:left;direction:ltr"> -L<h2 style=";text-align:left;direction:ltr"> L <h2 style=";text-align:left;direction:ltr"> )-L<h2 style=";text-align:left;direction:ltr"> CS2 <h2 style=";text-align:left;direction:ltr"> -(C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *V2-V<h2 style=";text-align:left;direction:ltr"> PR1 <h2 style=";text-align:left;direction:ltr"> )<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> / (2*a1)]*0.01 Based on the characteristics of PLC high-speed scanning, the formula is scanned, calculated and executed every 8 to 10 ms, and the flying shear speed is adjusted according to the speed change of the strip, so that the flying shear speed matches the speed change of the strip, and finally the shearing point of the shear blade and the intermediate billet coincides and the shearing is completed.

6. A dynamic speed control system for automatic shearing of hot rolling flying shear, characterized in that: include: Module M1: When the flying shear receives the head and tail shearing length of the strip set by the process automation level 2, the basic automation level 1 machine stores and updates the set head and tail shearing length; Module M2: When the heat inspection before the flying shear detects the strip head, the head tracking is started. When the distance from the starting position to the shearing position of the flying shear is greater than the sum of the distance from the head to the center line of the flying shear and the head cutting length, the flying shear starts the head cutting; When the heat inspection before the flying shear detects the tail of the strip, the tail tracking is started. When the distance from the starting position to the shearing position of the flying shear is greater than the difference between the distance from the tail to the center line of the flying shear and the tail cutting length, the flying shear starts to cut the tail. Module M3: When the slab speed changes during startup, the distance from the shear point to the flying shear will be updated in real time. The real-time changing proportional coefficient will be introduced according to the change of the distance, and the speed compensation finally calculated will be added to the set shear speed: The shorter the time from the intermediate billet shearing point to the flying shear shearing center line is than the expected time, the faster the flying shear is set, and vice versa.

7. The dynamic speed control system for automatic shearing of hot rolling flying shear according to claim 6 is characterized in that: Derivation of the shear calculation formula when flying shear head: During normal rolling, the secondary shear setting values ​​are sent down, including the cutting advance rate and cutting length; Using C LEAD Indicates the cutting lead rate, L TOP Indicates the distance from the head of the intermediate billet to the center line of the flying shear, L H Indicates the cutting length; When the head reaches the heat inspection before the flying shear, the strip head tracking is started, and the distance between the flying shear head knife and the shearing position is L CS1 , the acceleration of the flying shear is represented by a, and the traveling speed of the strip head itself is represented by V1; When cutting, the flying shear needs to accelerate from 0 to the shearing speed for a certain distance, and this distance is fixed and set to L. ACC1 , calculate in real time the time required for the slab head to reach the center line of the flying shear and the time required for the flying shear to move from the starting position to the shearing position, and compare the two in real time; the specific formula is: (L TOP +L H )*C LEAD =L CS1 +L ACC1 When the left side is smaller than the right side, the flying shear starts to turn; After the flying shear is started, the compensation speed is calculated, and the speed compensation proportional coefficient K is adjusted in real time according to the distance from the head shear point to the center line of the flying shear; the real-time speed compensation of the flying shear is determined according to the real-time speed of the flying shear, the leading rate / lag rate, and the real-time position of the flying shear. Finally, the actual speed compensation V of the flying shear head is calculated by multiplying the two. SPD COMPEN Therefore, the speed of the flying shear is set to V when it is automatically sheared. CS =C LEAD *V1+V SPD COMPEN .

8. The dynamic speed control system for automatic shearing of hot rolling flying shear according to claim 7 is characterized in that: The speed compensation calculation process is as follows: Assume that the real-time speed of the flying shear during the acceleration process is V PR , then the compensation speed calculation formula is: C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a) The final speed compensation value is: V SPD SPDCOMPEN =K*[C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)]*0.01 The actual shearing speed during the automatic shearing process of the flying shear is set as follows: V CS ACTUAL =C LEAD *V1+K*[C LEAD *(L TOP +L H )-L CS1 -(C LEAD *V1-V PR ) 2 / (2*a)]*0.01。 9. The dynamic speed control system for automatic shearing of hot rolling flying shear according to claim 8 is characterized in that: The calculation formula for the shear tail is as follows: During normal rolling, the secondary shear setting values ​​are sent down, including the cutting advance rate and cutting length; Using C LAG represents the tail-cutting hysteresis rate, L TAIL Indicates the distance from the tail of the intermediate billet to the center line of the flying shear, L L Indicates the tail cutting length; When the tail reaches the heat inspection before the flying shear, the strip tail tracking is started, and the distance between the tail knife of the flying shear and the shearing position is L CS2 , the acceleration of the flying shear is represented by a1, and the travel speed of the strip head itself is represented by V2; When cutting the tail, the flying shear needs to accelerate from 0 to the shearing speed for a certain distance, and this distance is fixed and set to L. ACC2 , calculate in real time the time required for the slab head to reach the center line of the flying shear and the time required for the flying shear to move from the starting position to the shearing position, and compare the two in real time; the specific formula is: (L TAIL -L L )*C LAG =L CS2 +L ACC2 When the left side is smaller than the right side, the flying shear starts to turn; After the flying shear is started, the compensation speed is calculated, and the proportional coefficient K of the speed compensation is adjusted in real time according to the distance from the tail shear point to the center line of the flying shear; the real-time speed compensation of the flying shear is determined according to the real-time speed of the flying shear, the leading rate / lag rate, and the real-time position of the flying shear. Finally, the actual speed compensation V of the flying shear head is calculated by multiplying the two. SPD COMPEN Therefore, the speed of the flying shear is set to V when it is automatically sheared. CS =C LAG *V2+V SPD COMPEN .

10. The dynamic speed control system for automatic shearing of hot rolling flying shear according to claim 9, characterized in that: The speed compensation calculation process is as follows: Assume that the real-time speed of the flying shear during the acceleration process is V PR1 , then the compensation speed calculation formula is: <h2 style=";text-align:left;direction:ltr">C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *(L<h2 style=";text-align:left;direction:ltr"> TAIL <h2 style=";text-align:left;direction:ltr"> -L<h2 style=";text-align:left;direction:ltr"> L <h2 style=";text-align:left;direction:ltr"> )-L<h2 style=";text-align:left;direction:ltr"> CS2 <h2 style=";text-align:left;direction:ltr"> -(C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *V2-V<h2 style=";text-align:left;direction:ltr"> PR1 <h2 style=";text-align:left;direction:ltr"> )<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> / (2*a1) The final speed compensation value is: <h2 style=";text-align:left;direction:ltr">V<h2 style=";text-align:left;direction:ltr"> SPD SPDCOMPEN <h2 style=";text-align:left;direction:ltr"> (K*[C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *(L<h2 style=";text-align:left;direction:ltr"> TAIL <h2 style=";text-align:left;direction:ltr"> -L<h2 style=";text-align:left;direction:ltr"> L <h2 style=";text-align:left;direction:ltr"> )-L<h2 style=";text-align:left;direction:ltr"> CS2 <h2 style=";text-align:left;direction:ltr"> -(C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *V2-V<h2 style=";text-align:left;direction:ltr"> PR1 <h2 style=";text-align:left;direction:ltr"> )<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> / (2*a1)]*0.01 The actual shearing speed during the automatic shearing process of the flying shear is set as follows: <h2 style=";text-align:left;direction:ltr">V<h2 style=";text-align:left;direction:ltr"> CS ACTUAL <h2 style=";text-align:left;direction:ltr"> =C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *V2+K*[C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *(L<h2 style=";text-align:left;direction:ltr"> TAIL <h2 style=";text-align:left;direction:ltr"> -L<h2 style=";text-align:left;direction:ltr"> L <h2 style=";text-align:left;direction:ltr"> )-L<h2 style=";text-align:left;direction:ltr"> CS2 <h2 style=";text-align:left;direction:ltr"> -(C<h2 style=";text-align:left;direction:ltr"> LAG <h2 style=";text-align:left;direction:ltr"> *V2-V<h2 style=";text-align:left;direction:ltr"> PR1 <h2 style=";text-align:left;direction:ltr"> )<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> / (2*a1)]*0.01 Based on the characteristics of PLC high-speed scanning, the formula is scanned, calculated and executed every 8 to 10 ms, and the flying shear speed is adjusted according to the speed change of the strip, so that the flying shear speed matches the speed change of the strip, and finally the shearing point of the shear blade and the intermediate billet coincides and the shearing is completed.

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