Transmission speed control method in dynamic specification changing process of tandem cold rolling mill

Abstract

The invention provides a method for controlling the transmission speed in the dynamic specification changing process of a tandem cold rolling mill, and relates to the technical field of electrical control of tandem cold rolling mills, and the method comprises the following steps: determining the speed of each rolling mill stand in the dynamic specification changing process to control a wedge-shaped adjustment coefficient; determining the total speed control wedge coefficient of each rolling mill rack in the dynamic specification changing process; the transmission speed coefficient of each rolling mill stand is determined according to the strip steel speed coefficient of the outlet of each rolling mill stand before wedge forming, the total wedge-shaped coefficient of the transmission speed and the forward slip coefficient before wedge forming; according to the transmission speed coefficient of each rolling mill rack and the outlet strip steel speed set value of the main speed slope, the transmission speed set value of each rolling mill rack is determined, and the transmission speed set value of each rolling mill rack is sent to a variable frequency controller of corresponding transmission; and the transmission speed control of each rolling mill stand is realized through the speed closed-loop control of the variable-frequency controller. According to the method, the speed and thickness control precision of the continuous mill in the dynamic specification changing process can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of electrical control of a cold rolling mill, and in particular to a method for controlling a transmission speed of a cold rolling mill during a dynamic specification change process. Background Art

[0002] Typical cold rolling mill equipment layout Figure 1 As shown, its main components include a correction roller 1 at the entrance of the rolling mill, a tension roller 2 at the entrance of the rolling mill (in the advanced second flow control, it is regarded as the 0# frame participating in the thickness control), 1-5# rolling mill frames 4-8, a flying shear 11 at the exit of the rolling mill, a clamping roller 10 in front of the flying shear at the exit of the rolling mill, a steering roller 12 at the exit of the rolling mill, a coiler 13, as well as large instruments such as a tension measuring roller 3 and a plate shape roller 9 at the exit of the rolling mill, a transmission reducer 14, a transmission motor 15, and a transmission speed encoder 16.

[0003] Before the pickled cold-rolled strip 17 reaches the rolling mill, the correcting roller 1 at the mill entrance ensures that the strip 17 is centered when entering the rolling mill; the tension roller 2 at the mill entrance is responsible for establishing the strip tension at the mill entrance, or participating in thickness control as a 0# frame; 1-5# rolling mill frames 4-8 achieve comprehensive control of the tension, thickness and speed of the target strip 17 by controlling the hydraulic pressure and frame transmission speed, so that the strip 17 at the mill outlet reaches the set thickness; the split coils or welds are cut at the mill outlet flying shear 11, and the finished strip 17 after rolling is wound into a coil by the coiler 13.

[0004] For cold rolling mills, the strip thickness at the mill exit is the most important control object. The secondary model distributes the load to each stand according to the strip raw material thickness and the target thickness, and pre-calculates the proportional relationship between the strip speed at the mill entrance and each stand exit, converting thickness control into speed control.

[0005] According to the secondary setting, the proportional coefficient between the strip speed at the mill entrance and each stand exit relative to the strip speed at the mill exit (hereinafter referred to as the strip speed coefficient) is obtained by the following calculation (taking the 1# stand as an example). This proportional coefficient clarifies the proportional relationship between each stand in eliminating the strip thickness difference. In the absence of manual intervention in the strip speed at the exit of each stand (i.e., manual adjustment of the load of each stand), this ratio is fixed. Thickness control and inter-stand tension control only fine-tune each transmission speed based on this proportional coefficient.

[0006]

[0007] Among them, PFX1 is the strip speed coefficient at the exit of 1# rolling mill stand 4; VX SDH 1 VX is the speed setting value of the strip at the exit of the 1# rolling mill stand 4 from the second level; SDH 5It is the set value of the exit strip speed of 5# rolling mill frame 8 coming from the secondary stage.

[0008] Taking the actual strip speed setting value V_MR1 at the outlet of the last stand as the benchmark, the speed setting value of each stand transmission is calculated through the strip speed coefficient at the outlet of each stand and the forward slip setting value of each stand, so as to realize the speed control of the transmission by the basic automation system. The calculation formula (taking the 1# rolling mill stand 4 as an example) is as follows:

[0009]

[0010] Among them, VS1 is the speed setting value of the 1# rolling mill frame 4 transmission; V_MR1 is the speed setting value of the strip steel at the mill outlet of the main speed ramp; PFX1 is the strip steel speed coefficient at the 1# rolling mill frame 4 outlet; SLA SDH 1 It is the forward slip setting value of the 1# rolling mill frame 4 from the second level.

[0011] In the continuous rolling process, when passing the weld, recalculating the secondary setting value, or passing the thick strip head, the wedge control should be used to dynamically switch the rolling specifications, such as Figure 2 As shown. Before dynamic specification change, the second level sends the wedge parameters to the basic automation system, including: the starting position of the wedge area, and the total length of the wedge area after each stand L_WDG_setp. When the starting position of the wedge area reaches the 1# rolling mill stand 4, the wedge rolling is started, and the wedge tracking of the 1# rolling mill stand 4 is first performed: the length value L_WDG_act1 of the wedge area passing through the 1# rolling mill stand 4 is calculated by the speed of the strip after the 1# rolling mill stand 4, and the actual number of wedge steps WDG_STEP1 after the 1# rolling mill stand 4 is calculated using the following formula:

[0012]

[0013] Among them, L_WDG_setp1 is the total length of the wedge area from the second level after passing through the 1# rolling mill stand 4; WDG_STEP_n is the total step value of the wedge (a fixed value, such as 20 steps). Then the wedge coefficient WDG1 of the 1# rolling mill stand 4 is calculated using the following formula:

[0014]

[0015] If the length of the wedge area passing through the 1# rolling mill stand 4 is greater than the distance between the 1# rolling mill stand 4 and the 2# rolling mill stand 5 (i.e. the starting position of the wedge area reaches the 2# rolling mill stand 5), then the wedge tracking of the 2# rolling mill stand 5 is triggered. The wedge rolling process from the 2# rolling mill stand 5 to the 5# rolling mill stand 8 is similar to that of the 1# rolling mill stand 4. If the actual number of wedge steps after the 5# rolling mill stand 8 is greater than or equal to the set total number of steps, then the wedge rolling is completed.

[0016] This traditional wedge control method takes a single stand as the control object and only generates a wedge coefficient WDG when the wedge area reaches the stand for the wedge transition control of the stand's press, speed, roll bending and roll shifting. For a continuous rolling mill, this control method fails to consider the impact of the stand's wedge transition on the front and rear stands, so it cannot be directly applied to continuous rolling mill control. Summary of the invention

[0017] The purpose of the present invention is to provide a method for controlling the transmission speed of a cold rolling mill during the dynamic specification change process. According to the wedge coefficient, the change of the set value before and after the wedge, and the mutual influence of the speed control of the front and rear racks, the speed set value of all transmissions in the rolling mill area during the dynamic specification change process is calculated, thereby improving the control accuracy of the speed and thickness of the rolling mill during the dynamic specification change process, ensuring the stability of the wedge control process, reducing the probability of belt breakage, ensuring the stability of the unit, and improving production efficiency. The specific technical scheme is as follows:

[0018] A method for controlling the transmission speed during the dynamic specification change process of a cold rolling mill, the method comprising the following steps:

[0019] S100, determining the speed control wedge adjustment coefficient of each rolling mill stand itself during the dynamic gauge change process: determining the wedge adjustment coefficient of the inlet strip speed of each rolling mill stand, the rolling mill stand transmission speed and the outlet strip speed of the rolling mill stand according to the following wedge setting values ​​including the wedge coefficient of each rolling mill stand, the strip thickness before and after the wedge at the inlet and outlet, the forward slip coefficient before and after the wedge, and the strip speed coefficient before and after the wedge at the outlet;

[0020] S200, determining the total speed control wedge coefficient of each rolling mill stand during the dynamic specification change process: starting from the last rolling mill stand, reversely calculating the total wedge coefficient of the inlet strip steel speed, the frame transmission speed and the outlet strip steel speed of each rolling mill stand; for the last rolling mill stand, the total wedge coefficient of its inlet strip steel speed, the frame transmission speed and the outlet strip steel speed is determined by the wedge adjustment coefficient of its inlet strip steel speed, the rolling mill frame transmission speed and the rolling mill frame outlet strip steel speed; for the rolling mill stands before the last stage, the total wedge coefficient of its inlet strip steel speed, the frame transmission speed and the outlet strip steel speed is determined by the wedge adjustment coefficient of its inlet strip steel speed, the rolling mill frame transmission speed and the rolling mill frame outlet strip steel speed and the wedge adjustment coefficient of the inlet strip steel speed, the rolling mill frame transmission speed and the rolling mill frame outlet strip steel speed of the subsequent rolling mill stands;

[0021] S300, determining the transmission speed coefficient of each rolling mill frame according to the strip speed coefficient before the wedge at the exit of each rolling mill frame, the total wedge coefficient of the transmission speed and the forward slip coefficient before the wedge;

[0022] S400, determine the speed setting value of each rolling mill frame transmission according to the speed coefficient of each rolling mill frame transmission and the outlet strip speed setting value of the main speed ramp, send the speed setting value of each rolling mill frame transmission to the frequency conversion controller of the corresponding transmission, and realize the speed control of each rolling mill frame transmission during the dynamic specification change process through the speed closed-loop control of the frequency conversion controller.

[0023] Furthermore, in step S100, the calculation formula of the wedge adjustment coefficient of the strip speed at the entrance of the final rolling mill stand, the transmission speed of the rolling mill stand and the strip speed at the exit of the rolling mill stand is as follows:

[0024]

[0025] Among them, K is the series number of the last rolling mill stand of the multi-stand cold rolling mill, FVH K FVS is the wedge adjustment coefficient of the strip speed at the entrance of the final rolling mill stand; K FVX is the wedge adjustment coefficient of the transmission speed of the final rolling mill stand; K HNN is the wedge adjustment coefficient of the strip speed at the exit of the final rolling mill stand; K HXN is the strip thickness after the wedge at the entrance of the final rolling mill stand; K The strip thickness after the wedge at the exit of the final rolling mill stand; SLN K is the forward slip coefficient of the wedge-shaped stand of the final rolling mill; HNA K HXA is the strip thickness before the wedge at the entrance of the final rolling mill stand; K SLA is the strip thickness before the wedge at the exit of the final rolling mill stand; K PFXA is the slip coefficient before the wedge of the final rolling mill stand; K PFXN is the strip speed coefficient before the wedge at the exit of the final rolling mill stand; K WDG is the strip speed coefficient after the wedge at the exit of the final rolling mill stand; K is the wedge coefficient of the final rolling mill stand;

[0026] The calculation formula for the wedge adjustment coefficient of the strip speed at the entrance of each stage of the rolling mill stand before the last stage, the transmission speed of the rolling mill stand and the strip speed at the exit of the rolling mill stand is as follows:

[0027]

[0028] FVX J =1.0

[0029] Where J is the serial number of each rolling mill stand before the last stage of the multi-stand cold rolling mill, ranging from 1 to (K-1), FVH J FVS is the wedge adjustment coefficient of the strip speed at the entrance of each stage of the rolling mill stand before the last stage; JFVX is the wedge adjustment coefficient of the transmission speed of each stage of the rolling mill stand before the last stage; J HNN is the wedge adjustment coefficient of the strip speed at the exit of each stage of the rolling mill stand before the last stage; J The thickness of the strip after the wedge at the entrance of each stage of the rolling mill stand before the last stage; HXN J The thickness of the strip after the wedge at the exit of each stage of the rolling mill stand before the last stage; SLN J HNA is the forward slip coefficient of the wedge-shaped rolling mill stands in front of the last stage; J HXA is the strip thickness before the wedge at the entrance of each stage of the rolling mill stand before the last stage. J SLA is the strip thickness before the wedge at the exit of each stage of the rolling mill stand before the final stage; J WDG is the forward slip coefficient of the wedge-shaped rolling mill stands in front of the last stage; J It is the wedge coefficient of each stage of rolling mill frames before the last stage.

[0030] Furthermore, in step S200, the calculation formula of the total wedge coefficient of the inlet strip speed of the final rolling mill frame, the frame transmission speed and the outlet strip speed is as follows:

[0031] WDG_H K =1.0×FVH K =FVH K

[0032] WDG_S K =1.0×FVS K =FVS K

[0033] WDG_X K =1.0×FVX K =FVX K

[0034] Among them, WDG_H K is the total wedge coefficient of the strip speed at the entrance of the final rolling mill stand; WDG_S K is the total wedge coefficient of the transmission speed of the final rolling mill stand; WDG_X K is the total wedge factor of the strip speed at the exit of the final rolling mill stand;

[0035] The calculation formula for the total wedge coefficient of the inlet strip speed, rack transmission speed and outlet strip speed of each stage of the rolling mill stand before the final stage is as follows:

[0036] WDG_H J =WDG_H J+1 ×FVH J =FVH K ×FVH K-1 ×…×FVHJ+1 ×FVH J

[0037] WDG_S J =WDG_H J+1 ×FVS J =FVH K ×FVH K-1 ×…×FVH J+1 ×FVS J

[0038] WDG_X J =WDG_H J+1 ×FVX J =FVH K ×FVH K-1 ×…×FVH J+1 ×FVX J

[0039] Among them, WDG_H J WDG_S is the total wedge coefficient of the strip speed at the entrance of each stage of the rolling mill stand before the last stage; J is the total wedge coefficient of the transmission speed of each stage of the rolling mill stand before the last stage; WDG_X J It is the total wedge coefficient of the exit strip speed of each stage of the rolling mill stands before the last stage.

[0040] Furthermore, in step S300, the speed coefficient of the final rolling mill frame transmission is calculated as follows:

[0041]

[0042] Among them, PFS WDG_K is the speed coefficient of the final mill stand drive during the wedge process;

[0043] The calculation formula for the speed coefficient of each stage of rolling mill frame transmission before the final stage is as follows:

[0044]

[0045] Among them, PFS WDG_J PFXA is the speed coefficient of the rolling mill rack transmission in the wedge process before the final stage; J SLA is the strip speed coefficient before the wedge at the exit of each stage of the rolling mill stand in front of the last stage; J It is the forward slip coefficient in front of the wedge of each stage of rolling mill stands in front of the last stage.

[0046] Furthermore, in step S400, the calculation formula of the speed setting value of the final rolling mill frame transmission is as follows:

[0047]

[0048] Among them, VS WDG_K is the speed setting value of the final rolling mill stand transmission in the wedge process; V_MR1 is the exit strip speed setting value of the main speed ramp;

[0049] The calculation formula for the speed setting value of each stage of the rolling mill frame transmission before the final stage is as follows:

[0050]

[0051] Among them, VS WDG_J It is the speed setting value of the rolling mill frame transmission at each stage before the last stage in the wedge process.

[0052] Furthermore, the strip speed coefficient at the outlet of the final rolling mill frame is determined according to the strip speed coefficient before the wedge at the outlet of the final rolling mill frame and the total wedge coefficient of the outlet strip speed; the speed setting value of the transmission after the final rolling mill frame is determined according to the strip speed coefficient at the outlet of the final rolling mill frame and the outlet strip speed setting value of the main speed ramp, the speed setting value of the transmission after the final rolling mill frame is sent to the frequency conversion controller of the corresponding transmission, and the speed control of the transmission after the final rolling mill frame during the dynamic specification change process is realized through the speed closed-loop control of the frequency conversion controller.

[0053] Furthermore, the calculation formula of the strip speed coefficient at the exit of the final rolling mill stand is as follows:

[0054] PFX WDG _ K =PFXA K ×WDG_X K =PFXA K ×FVX K

[0055] Among them, PFX WDG_K is the strip speed coefficient at the exit of the final mill stand during the wedge process;

[0056] The calculation formula for the speed setting value of the transmission after the final rolling mill stand is as follows:

[0057] VX WDG_K =V_MR1×PFX WDG_K =V_MR1×PFXA K ×FVX K

[0058] Among them, VX WDG_K It is the speed setting value of the transmission after the final rolling mill stand during the wedge process.

[0059] Furthermore, it also includes determining the wedge adjustment coefficient of the inlet strip speed, transmission speed and outlet strip speed of the inlet tension roller of the rolling mill during the dynamic specification change process; determining the total speed control wedge coefficient of the inlet tension roller of the rolling mill during the dynamic specification change process: the total wedge coefficient of its inlet strip speed, transmission speed and outlet strip speed is determined by the wedge adjustment coefficients of its inlet strip speed, transmission speed and outlet strip speed and the inlet strip speed, rolling mill frame transmission speed and outlet strip speed of the subsequent rolling mill frames at all levels respectively; determining the speed coefficient of the inlet tension roller transmission of the rolling mill according to the strip speed coefficient before the wedge at the outlet of the inlet tension roller of the rolling mill, the total wedge coefficient of the transmission speed and the forward slip coefficient before the wedge; determining the speed setting value of the inlet tension roller transmission of the rolling mill according to the speed coefficient of the inlet tension roller transmission of the rolling mill and the outlet strip speed setting value of the main speed slope, sending the speed setting value of the inlet tension roller transmission of the rolling mill to the frequency converter controller of the corresponding transmission, and realizing the speed control of the inlet tension roller transmission of the rolling mill during the dynamic specification change process through the speed closed-loop control of the frequency converter controller.

[0060] Furthermore, the wedge adjustment coefficients of the inlet strip speed, transmission speed and outlet strip speed of the inlet tension roller of the rolling mill are as follows:

[0061] FVH0=1.0

[0062] FVS0=1.0

[0063] FVX0=1.0

[0064] Among them, FVH0 is the wedge adjustment coefficient of the strip speed of the entrance tension roller of the rolling mill; FVS0 is the wedge adjustment coefficient of the transmission speed of the entrance tension roller of the rolling mill; FVX0 is the wedge adjustment coefficient of the strip speed of the exit tension roller of the rolling mill;

[0065] The total wedge coefficient calculation formula of the inlet strip speed, transmission speed and outlet strip speed of the rolling mill entrance tension roller is as follows:

[0066] WDG_H0=WDG_H1×FVH0=FVH K ×FVH K-1 ×…×FVH J ×…×FVH2×FVH1×FVH0

[0067] WDG_S0=WDG_H1×FVS0=FVH K ×FVH K-1 ×…×FVH J ×…×FVH2×FVH1×FVS0

[0068] WDG_X0=WDG_H1×FVX0=FVH K ×FVHK-1 ×…×FVH J ×…×FVH2×FVH1×FVX0

[0069] Among them, WDG_H0 is the total wedge coefficient of the strip speed at the entrance of the rolling mill tension roller; WDG_S0 is the total wedge coefficient of the transmission speed of the entrance of the rolling mill tension roller; WDG_X0 is the total wedge coefficient of the strip speed at the exit of the entrance of the rolling mill tension roller;

[0070] The speed coefficient calculation formula of the rolling mill entrance tension roller transmission is as follows:

[0071]

[0072] Among them, PFS WDG_0 is the speed coefficient of the mill entrance tension roller transmission during the wedge process; PFXA0 is the strip speed coefficient before the wedge at the mill entrance tension roller outlet; SLA0 is the forward slip coefficient before the wedge at the mill entrance tension roller, which is always 1.0;

[0073] The calculation formula for the speed setting value of the tension roller transmission at the rolling mill entrance is as follows:

[0074] VS WDG_0 =V_MR1×PFS WDG_0 =V_MR1×PFXA0×FVH5×FVH4×FVH3×FVH2×FVH1

[0075] Among them, VS WDG_0 It is the speed setting value of the mill entrance tension roller drive during the wedge process.

[0076] Furthermore, the tandem cold rolling mill is a five-stand tandem cold rolling mill.

[0077] The present invention provides a method for controlling the transmission speed of a cold rolling mill during dynamic specification change, which has the following beneficial effects:

[0078] (1) The present invention determines the wedge adjustment coefficient of the inlet strip speed, frame transmission speed and outlet strip speed of each frame according to the wedge coefficient and the strip thickness setting value at the inlet and outlet of the frames before and after the wedge, the forward sliding setting value and the strip speed coefficient at the frame outlet, and reversely determines the total wedge coefficient of the inlet strip speed, frame transmission speed and outlet strip speed of each frame starting from the last rolling mill frame. When determining the total wedge coefficient of the frame, the influence of the wedge control of the latter frame on its inlet strip speed is taken into account. The transmission coefficient of each frame is determined according to the total wedge coefficient. The speed coefficient calculates the speed setting value of the transmission according to the area where all the transmissions in the rolling mill area are located, and sends the speed setting value to the frequency converter of the corresponding transmission. The speed control of the transmission during the dynamic specification change process is realized through the speed closed-loop control of the frequency converter. When calculating the wedge coefficient of the speed control of each frame, the influence of the wedge control of the rear frame on the speed control of the current frame is fully considered, which improves the calculation accuracy of the speed setting value of the rolling mill during the unstable transition process of dynamic specification change, ensures the stability of the unit speed control, reduces the probability of belt breakage, and improves the stability of the unit.

[0079] (2) Moreover, the wedge coefficients of the strip speed at the rack entrance, the rack transmission speed, and the strip speed at the rack exit during the dynamic specification change process are calculated separately. For the control object - the transmission speed and the strip speed in the rolling mill area, the relationship between them is more intuitive and more conducive to process optimization in the production process.

[0080] (3) In addition, this control method is well adapted to the current mainstream control concept of cold rolling mills. The control idea is clear and the calculation process is complete, so that the speed control of the rolling mill transmission during the dynamic specification change process can be well realized through basic automatic control. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 This is a typical equipment layout diagram of a cold rolling mill.

[0082] Figure 2 Schematic diagram of wedge control.

[0083] Figure 3 The figure is a flow chart of a method for controlling the transmission speed during the dynamic specification change process of a cold rolling mill.

[0084] Figure 4 Schematic diagram of wedge-shaped speed control during dynamic specification change.

[0085] In the figure: 1-rolling mill entrance deviation correction roller; 2-rolling mill entrance tension roller; 3-tension measuring roller; 4-1# rolling mill frame; 5-2# rolling mill frame; 6-3# rolling mill frame; 7-4# rolling mill frame; 8-5# rolling mill frame; 9-rolling mill exit flatness roller; 10-rolling mill exit front pinch roller of flying shear; 11-rolling mill exit flying shear; 12-rolling mill exit steering roller; 13-coiler; 14-transmission reduction box; 15-transmission motor; 16-transmission speed encoder; 17-cold rolled strip. DETAILED DESCRIPTION

[0086] The following will be combined with the accompanying drawings provided by the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. According to the following description, the advantages and features of the present invention will be more clear. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0087] This embodiment provides a method for controlling the transmission speed during the dynamic specification change process of a cold rolling mill. Figure 3 As shown, the method comprises the following steps:

[0088] S100, determining the speed control wedge adjustment coefficient of each rolling mill stand itself during the dynamic gauge change process: determining the wedge adjustment coefficient of the inlet strip speed of each rolling mill stand, the rolling mill stand transmission speed and the outlet strip speed of the rolling mill stand according to the following wedge setting values ​​including the wedge coefficient of each rolling mill stand, the strip thickness before and after the wedge at the inlet and outlet, the forward slip coefficient before and after the wedge, and the strip speed coefficient before and after the wedge at the outlet;

[0089] S200, determining the total speed control wedge coefficient of each rolling mill stand during the dynamic specification change process: starting from the last rolling mill stand, reversely calculating the total wedge coefficient of the inlet strip steel speed, the frame transmission speed and the outlet strip steel speed of each rolling mill stand; for the last rolling mill stand, the total wedge coefficient of its inlet strip steel speed, the frame transmission speed and the outlet strip steel speed is determined by the wedge adjustment coefficient of its inlet strip steel speed, the rolling mill frame transmission speed and the rolling mill frame outlet strip steel speed; for the rolling mill stands before the last stage, the total wedge coefficient of its inlet strip steel speed, the frame transmission speed and the outlet strip steel speed is determined by the wedge adjustment coefficient of its inlet strip steel speed, the rolling mill frame transmission speed and the rolling mill frame outlet strip steel speed and the wedge adjustment coefficient of the inlet strip steel speed, the rolling mill frame transmission speed and the rolling mill frame outlet strip steel speed of the subsequent rolling mill stands;

[0090] S300, determining the transmission speed coefficient of each rolling mill frame according to the strip speed coefficient before the wedge at the exit of each rolling mill frame, the total wedge coefficient of the transmission speed and the forward slip coefficient before the wedge;

[0091] S400, determine the speed setting value of each rolling mill frame transmission according to the speed coefficient of each rolling mill frame transmission and the outlet strip speed setting value of the main speed ramp, send the speed setting value of each rolling mill frame transmission to the frequency conversion controller of the corresponding transmission, and realize the speed control of each rolling mill frame transmission during the dynamic specification change process through the speed closed-loop control of the frequency conversion controller.

[0092] In the embodiment of the present invention, the wedge adjustment coefficients of the inlet strip speed, the frame transmission speed and the outlet strip speed of each frame are determined according to the wedge coefficient and the strip thickness setting values ​​at the inlet and outlet of the frames before and after the wedge, the forward sliding setting value and the strip speed coefficient at the frame outlet, etc., and the total wedge coefficient of the inlet strip speed, the frame transmission speed and the outlet strip speed of each frame is reversely determined starting from the last rolling mill frame. When determining the total wedge coefficient of the frame, the influence of the wedge control of the latter frame on its inlet strip speed is taken into account, and the transmission coefficient of each frame is determined according to the total wedge coefficient. Speed ​​coefficient, calculate the speed setting value of the transmission according to the area where all the transmissions in the rolling mill area are located, send the speed setting value to the frequency converter of the corresponding transmission, and realize the speed control of the transmission in the process of dynamic specification change through the speed closed-loop control of the frequency converter; because when calculating the wedge coefficient of the speed control of each frame, the influence of the wedge control of the rear frame on the speed control of the frame is fully considered, the calculation accuracy of the speed setting value of the rolling mill in the unstable transition process of dynamic specification change is improved, the stability of the unit speed control is guaranteed, the probability of strip breakage is reduced, and the stability of the unit is improved. Moreover, the wedge coefficients of the frame inlet strip speed, frame transmission speed and frame outlet strip speed in the process of dynamic specification change are calculated separately. For the control object-the transmission speed and strip speed of the rolling mill area, the relationship between them is more intuitive, which is more conducive to process optimization in the production process. In addition, this control method is well adapted to the current mainstream control idea of ​​cold rolling mills, with clear control ideas and complete calculation process, so that the speed control of the rolling mill transmission in the process of dynamic specification change can be well realized through basic automation control.

[0093] In one embodiment, in step S100, the calculation formula of the wedge adjustment coefficient of the strip speed at the entrance of the final rolling mill stand, the transmission speed of the rolling mill stand and the strip speed at the exit of the rolling mill stand is as follows:

[0094]

[0095] Among them, K is the series number of the last rolling mill stand of the multi-stand cold rolling mill, FVH K FVS is the wedge adjustment coefficient of the strip speed at the entrance of the final rolling mill stand; K FVX is the wedge adjustment coefficient of the transmission speed of the final rolling mill stand; K HNN is the wedge adjustment coefficient of the strip speed at the exit of the final rolling mill stand; KHXN is the strip thickness after the wedge at the entrance of the final rolling mill stand; K The strip thickness after the wedge at the exit of the final rolling mill stand; SLN K is the forward slip coefficient of the wedge-shaped stand of the final rolling mill; HNA K HXA is the strip thickness before the wedge at the entrance of the final rolling mill stand; K SLA is the strip thickness before the wedge at the exit of the final rolling mill stand; K PFXA is the slip coefficient before the wedge of the final rolling mill stand; K PFXN is the strip speed coefficient before the wedge at the exit of the final rolling mill stand; K WDG is the strip speed coefficient after the wedge at the exit of the final rolling mill stand; K is the wedge coefficient of the final rolling mill stand;

[0096] The calculation formula for the wedge adjustment coefficient of the strip speed at the entrance of each stage of the rolling mill stand before the last stage, the transmission speed of the rolling mill stand and the strip speed at the exit of the rolling mill stand is as follows:

[0097]

[0098] FVX I =1.0

[0099] Where J is the serial number of each rolling mill stand before the last stage of the multi-stand cold rolling mill, ranging from 1 to (K-1), FVH J FVS is the wedge adjustment coefficient of the strip speed at the entrance of each stage of the rolling mill stand before the last stage; J FVX is the wedge adjustment coefficient of the transmission speed of each stage of the rolling mill stand before the last stage; J HNN is the wedge adjustment coefficient of the strip speed at the exit of each stage of the rolling mill stand before the last stage; J The thickness of the strip after the wedge at the entrance of each stage of the rolling mill stand before the last stage; HXN J The thickness of the strip after the wedge at the exit of each stage of the rolling mill stand before the last stage; SLN J HNA is the forward slip coefficient of the wedge-shaped rolling mill stands in front of the last stage; J HXA is the strip thickness before the wedge at the entrance of each stage of the rolling mill stand before the last stage. J SLA is the strip thickness before the wedge at the exit of each stage of the rolling mill stand before the final stage; J WDG is the forward slip coefficient of the wedge-shaped rolling mill stands in front of the last stage; J It is the wedge coefficient of each stage of rolling mill frames before the last stage.

[0100] In one embodiment, in step S200, the total wedge coefficient of the final rolling mill stand entrance strip speed, stand transmission speed and exit strip speed is calculated as follows:

[0101] WDG_H K =1.0×FVH K =FVH K

[0102] WDG_S K =1.0×FVS K =FVS K

[0103] WDG_X K =1.0×FVX K =FVX K

[0104] Among them, WDG_H K is the total wedge coefficient of the strip speed at the entrance of the final rolling mill stand; WDG_S K is the total wedge coefficient of the transmission speed of the final rolling mill stand; WDG_X K is the total wedge factor of the strip speed at the exit of the final rolling mill stand;

[0105] The calculation formula for the total wedge coefficient of the inlet strip speed, rack transmission speed and outlet strip speed of each stage of the rolling mill stand before the final stage is as follows:

[0106] WDG_H J =WDG_H J+1 ×FVH J =FVH K ×FVH K-1 ×…×FVH J+1 ×FVH J

[0107] WDG_S J =WDG_H J+1 ×FVS J =FVH K ×FVH K-1 ×…×FVH J+1 ×FVS J

[0108] WDG_X J =WDG_H J+1 ×FVX J =FVH K ×FVH K-1 ×…×FVH J+1 ×FVX J

[0109] Among them, WDG_H J WDG_S is the total wedge coefficient of the strip speed at the entrance of each stage of the rolling mill stand before the last stage; Jis the total wedge coefficient of the transmission speed of each stage of the rolling mill stand before the last stage; WDG_X J It is the total wedge coefficient of the exit strip speed of each stage of the rolling mill stands before the last stage.

[0110] In one embodiment, in step S300, the speed coefficient of the final rolling mill frame transmission is calculated as follows:

[0111]

[0112] Among them, PFS WDG_K is the speed coefficient of the final mill stand drive during the wedge process;

[0113] The calculation formula for the speed coefficient of each stage of rolling mill frame transmission before the final stage is as follows:

[0114]

[0115] Among them, PFS WDG_J PFXA is the speed coefficient of the rolling mill rack transmission in the wedge process before the final stage; J SLA is the strip speed coefficient before the wedge at the exit of each stage of the rolling mill stand in front of the last stage; J It is the forward slip coefficient in front of the wedge of each stage of rolling mill stands in front of the last stage.

[0116] In one embodiment, in step S400, the calculation formula of the speed setting value of the final rolling mill frame transmission is as follows:

[0117]

[0118] Among them, VS WDG_K is the speed setting value of the final rolling mill stand transmission in the wedge process; V_MR1 is the exit strip speed setting value of the main speed ramp;

[0119] The calculation formula for the speed setting value of each stage of the rolling mill frame transmission before the final stage is as follows:

[0120]

[0121] Among them, VS WDG_J It is the speed setting value of the rolling mill frame transmission at each stage before the last stage in the wedge process.

[0122] In one embodiment, the strip speed coefficient at the outlet of the final rolling mill frame is also determined based on the strip speed coefficient before the wedge at the outlet of the final rolling mill frame and the total wedge coefficient of the outlet strip speed; the speed setting value of the transmission after the final rolling mill frame is determined based on the strip speed coefficient at the outlet of the final rolling mill frame and the outlet strip speed setting value of the main speed ramp, and the speed setting value of the transmission after the final rolling mill frame is sent to the frequency conversion controller of the corresponding transmission, and the speed control of the transmission after the final rolling mill frame during the dynamic specification change process is realized through the speed closed-loop control of the frequency conversion controller.

[0123] In one embodiment, the calculation formula of the strip speed coefficient at the exit of the final rolling mill stand is as follows:

[0124] PFX WDG_K =PFXA K ×WDG_X K =PFXA K ×FVX K

[0125] Among them, PFX WDG_K is the strip speed coefficient at the exit of the final mill stand during the wedge process;

[0126] The calculation formula for the speed setting value of the transmission after the final rolling mill stand is as follows:

[0127] VX WDG_K =V_MR1×PFX WDG_K =V_MR1×PFXA K ×FVX K

[0128] Among them, VX WDG_K It is the speed setting value of the transmission after the final rolling mill stand during the wedge process.

[0129] In one embodiment, it also includes determining the wedge adjustment coefficient of the inlet strip speed, transmission speed and outlet strip speed of the inlet tension roller of the rolling mill during the dynamic specification change process; determining the total speed control wedge coefficient of the inlet tension roller of the rolling mill during the dynamic specification change process: the total wedge coefficient of its inlet strip speed, transmission speed and outlet strip speed is respectively determined by the wedge adjustment coefficients of its inlet strip speed, transmission speed and outlet strip speed and the inlet strip speed, rolling mill frame transmission speed and outlet strip speed of the subsequent rolling mill frames at all levels; determining the speed coefficient of the inlet tension roller transmission of the rolling mill according to the strip speed coefficient before the wedge at the outlet of the inlet tension roller of the rolling mill, the total wedge coefficient of the transmission speed and the forward slip coefficient before the wedge; determining the speed setting value of the inlet tension roller transmission of the rolling mill according to the speed coefficient of the inlet tension roller transmission of the rolling mill and the outlet strip speed setting value of the main speed ramp, sending the speed setting value of the inlet tension roller transmission of the rolling mill to the frequency converter controller of the corresponding transmission, and realizing the speed control of the inlet tension roller transmission of the rolling mill during the dynamic specification change process through the speed closed-loop control of the frequency converter controller.

[0130] In one embodiment, the wedge adjustment coefficients of the inlet strip speed, the transmission speed and the outlet strip speed of the inlet tension roller of the rolling mill are as follows:

[0131] FVH0=1.0

[0132] FVS0=1.0

[0133] FVX0=1.0

[0134] Among them, FVH0 is the wedge adjustment coefficient of the strip speed of the entrance tension roller of the rolling mill; FVS0 is the wedge adjustment coefficient of the transmission speed of the entrance tension roller of the rolling mill; FVX0 is the wedge adjustment coefficient of the strip speed of the exit tension roller of the rolling mill;

[0135] The total wedge coefficient calculation formula of the inlet strip speed, transmission speed and outlet strip speed of the rolling mill entrance tension roller is as follows:

[0136] WDG_H0=WDG_H1×FVH0=FVH K ×FVH K-1 ×…×FVH J ×…×FVH2×FVH1×FVH0

[0137] WDG_S0=WDG_H1×FVS0=FVH K ×FVH K-1 ×…×FVH J ×…×FVH2×FVH1×FVS0

[0138] WDG_X0=WDG_H1×FVX0=FVH K ×FVHK-1 ×…×FVH J ×…×FVH2×FVH1×FVX0

[0139] Among them, WDG_H0 is the total wedge coefficient of the strip speed at the entrance of the rolling mill tension roller; WDG_S0 is the total wedge coefficient of the transmission speed of the entrance of the rolling mill tension roller; WDG_X0 is the total wedge coefficient of the strip speed at the exit of the entrance of the rolling mill tension roller;

[0140] The speed coefficient calculation formula of the rolling mill entrance tension roller transmission is as follows:

[0141]

[0142] Among them, PFS WDG_0 is the speed coefficient of the mill entrance tension roller transmission during the wedge process; PFXA0 is the strip speed coefficient before the wedge at the mill entrance tension roller outlet; SLA0 is the forward slip coefficient before the wedge at the mill entrance tension roller, which is always 1.0;

[0143] The calculation formula for the speed setting value of the tension roller transmission at the rolling mill entrance is as follows:

[0144] VS WDG_0 =V_MR1×PFS WDG_0 =V_MR1×PFXA0×FVH5×FVH4×FVH3×FVH2×FVH1

[0145] Among them, VS WDG_0 It is the speed setting value of the mill entrance tension roller drive during the wedge process.

[0146] Exemplary Embodiments

[0147] See also Figure 4 As shown, a five-stand cold rolling mill is taken as an example to illustrate the specific process of the control method of the transmission speed during the dynamic specification change of the cold rolling mill. When the cold rolling mill performs dynamic switching of rolling specifications during the rolling process, the wedge transition area first reaches the 1# rolling mill frame 4 (that is, the 1# rolling mill frame 4 starts the wedge adjustment of the speed first), but because the strip steel and transmission speeds of the entire continuous rolling mill area are reversely adjusted based on the strip steel speed at the outlet of the 5# rolling mill frame 8, the front frame will also be affected by the wedge control of the rear frame during the wedge adjustment. Therefore, the wedge coefficient of each frame speed should be reversely calculated starting from the 5# rolling mill frame 8 during the entire dynamic specification change process.

[0148] 1. Wedge control of 5# rolling mill stand 8

[0149] When the starting position of the wedge area reaches the 5# rolling mill stand 8, the wedge control of the 5# rolling mill stand 8 is started according to the wedge coefficient setting value WDG5. During the wedge control of the 5# rolling mill stand 8, the strip speed at its entrance, the transmission speed of the stand and the strip speed at the stand exit will be affected by the wedge control and change.

[0150] The wedge adjustment coefficients of the inlet strip speed, the frame transmission speed and the outlet strip speed of the 5# rolling mill stand 8 are calculated as follows:

[0151]

[0152] Among them, FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# rolling mill frame; FVS5 is the wedge adjustment coefficient of the transmission speed of the 5# rolling mill frame; FVX5 is the wedge adjustment coefficient of the strip speed at the exit of the 5# rolling mill frame; HNN5 is the strip thickness after the wedge at the entrance of the 5# rolling mill frame; HXN5 is the strip thickness after the wedge at the exit of the 5# rolling mill frame; SLN5 is the forward slip coefficient after the wedge of the 5# rolling mill frame; HNA5 is the strip thickness before the wedge at the entrance of the 5# rolling mill frame; HXA5 is the strip thickness before the wedge at the exit of the 5# rolling mill frame; SLA5 is the forward slip coefficient before the wedge of the 5# rolling mill frame; PFXA5 is the strip speed coefficient before the wedge at the exit of the 5# rolling mill frame; PFXN5 is the strip speed coefficient after the wedge at the exit of the 5# rolling mill frame; WDG5 is the wedge coefficient of the 5# rolling mill frame.

[0153] Because there is no rear stand, the speed of the 5# rolling mill stand 8 is only affected by its own wedge control. Then, during the dynamic gauge change process, the total wedge coefficient of the inlet strip speed, stand transmission speed and outlet strip speed of the 5# rolling mill stand 8 is calculated as follows:

[0154] WDG_H5=1.0×FVH5=FVH5

[0155] WDG_S5=1.0×FVS5=FVS5

[0156] WDG_X5=1.0×FVX5=FVX5

[0157] Among them, WDG_H5 is the total wedge coefficient of the strip speed at the entrance of the 5# rolling mill frame; WDG_S5 is the total wedge coefficient of the transmission speed of the 5# rolling mill frame; WDG_X5 is the total wedge coefficient of the strip speed at the exit of the 5# rolling mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# rolling mill frame; FVS5 is the wedge adjustment coefficient of the transmission speed of the 5# rolling mill frame; FVX5 is the wedge adjustment coefficient of the strip speed at the exit of the 5# rolling mill frame.

[0158] Then, during the dynamic specification change process, the strip speed coefficient at the exit of the 5# rolling mill stand is calculated as follows:

[0159] PFX WDG_5 =PFXA5×WDG_X5=PFXA5×FVX5

[0160] Among them, PFX WDG_5 It is the strip speed coefficient at the exit of 5# rolling mill frame during the wedging process; PFXA5 is the strip speed coefficient before the wedge at the exit of 5# rolling mill frame; WDG_X5 is the total wedge coefficient of the strip speed at the exit of 5# rolling mill frame; FVX5 is the wedge adjustment coefficient of the strip speed at the exit of 5# rolling mill frame.

[0161] During the dynamic specification change process, the speed coefficient of the 5# rolling mill stand transmission is calculated as follows:

[0162]

[0163] Among them, PFS WDG_5 It is the speed coefficient of the 5# mill frame transmission during the wedging process; PFXA5 is the strip speed coefficient before the wedge at the exit of the 5# mill frame; WDG_S5 is the total wedge coefficient of the 5# mill frame transmission speed; SLA5 is the forward slip coefficient before the wedge of the 5# mill frame; FVS5 is the wedge adjustment coefficient of the 5# mill frame transmission speed.

[0164] 1.5# Rolling Mill Frame Drive Speed ​​Setting Value Calculation

[0165] During the dynamic specification change process, the speed setting value of the 5# rolling mill frame transmission changes due to the influence of the speed coefficient of the 5# rolling mill frame transmission, and the calculation is as follows:

[0166]

[0167] Among them, VS WDG_5 is the speed setting value of the 5# rolling mill frame transmission during the wedge process; V_MR1 is the exit strip speed setting value of the main speed ramp; PFS WDG_5 It is the speed coefficient of the 5# mill frame transmission during the wedge process; PFXA5 is the strip speed coefficient before the wedge at the exit of the 5# mill frame; SLA5 is the forward slip coefficient before the wedge of the 5# mill frame; FVS5 is the wedge adjustment coefficient of the transmission speed of the 5# mill frame.

[0168] Calculation of the speed setting value of the transmission behind the 2.5# rolling mill stand

[0169] During the entire rolling process, the running speed of the transmission behind the 5# rolling mill stand is always consistent with the strip speed at the exit of the 5# rolling mill stand. Then, during the dynamic specification change process, the speed setting value of the transmission behind the 5# rolling mill stand changes due to the influence of the strip speed coefficient at the exit of the 5# rolling mill stand, and the calculation is as follows:

[0170] VX WDG_5 =V_MR1×PFX WDG_5 =V_MR1×PFXA5×FVX5

[0171] Among them, VX WDG_5 The strip speed setting value at the exit of the 5# rolling mill stand during the wedge process is the speed setting value of the transmission after the 5# rolling mill stand; V_MR1 is the exit strip speed setting value of the main speed ramp; PFX WDG 5 It is the strip speed coefficient at the exit of 5# rolling mill stand during the wedge process; PFXA5 is the strip speed coefficient before the wedge at the exit of 5# rolling mill stand; FVX5 is the wedge adjustment coefficient of the strip speed at the exit of 5# rolling mill stand.

[0172] 2. Wedge control of 4# rolling mill stand

[0173] When the starting position of the wedge area reaches the 4# rolling mill stand 7, the wedge control of the 4# rolling mill stand 7 is started according to the wedge coefficient setting value WDG4. During the wedge control of the 4# rolling mill stand 7, the strip speed at its entrance, the transmission speed of the stand and the strip speed at the stand exit will all be affected by the wedge control and change.

[0174] The wedge adjustment coefficients of the inlet strip speed, the frame transmission speed and the outlet strip speed of the 4# rolling mill stand 7 are calculated as follows:

[0175]

[0176]

[0177] FVX4=1.0

[0178] Among them, FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of the 4# rolling mill frame; FVS4 is the wedge adjustment coefficient of the transmission speed of the 4# rolling mill frame; FVX4 is the wedge adjustment coefficient of the strip speed at the exit of the 4# rolling mill frame; HNN4 is the strip thickness after the wedge at the entrance of the 4# rolling mill frame; HXN4 is the strip thickness after the wedge at the exit of the 4# rolling mill frame; SLN4 is the forward slip coefficient after the wedge of the 4# rolling mill frame; HNA4 is the strip thickness before the wedge at the entrance of the 4# rolling mill frame, HXA4 is the strip thickness before the wedge at the exit of the 4# rolling mill frame; SLA4 is the forward slip coefficient before the wedge of the 4# rolling mill frame; WDG4 is the wedge coefficient of the 4# rolling mill frame.

[0179] When the 5# rolling mill stand 8 performs wedge control, it affects the strip speed at its entrance, and indirectly affects the speed of the 4# rolling mill stand 7. Then, during the dynamic specification change process, the total wedge coefficient of the strip speed at the entrance, the stand transmission speed, and the strip speed at the exit of the 4# rolling mill stand is calculated as follows:

[0180] WDG_H4=WDG_H5×FVH4=FVH5×FVH4

[0181] WDG_S4=WDG_H5×FVS4=FVH5×FVS4

[0182] WDG_X4=WDG_H5×FVX4=FVH5×FVX4

[0183] Among them, WDG_H4 is the total wedge coefficient of the strip speed at the entrance of the 4# rolling mill frame; WDG_S4 is the total wedge coefficient of the transmission speed of the 4# rolling mill frame; WDG_X4 is the total wedge coefficient of the strip speed at the exit of the 4# rolling mill frame; WDG_H5 is the total wedge coefficient of the strip speed at the entrance of the 5# rolling mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# rolling mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of the 4# rolling mill frame; FVS4 is the wedge adjustment coefficient of the transmission speed of the 4# rolling mill frame; FVX4 is the wedge adjustment coefficient of the strip speed at the exit of the 4# rolling mill frame.

[0184] Then, during the dynamic specification change process, the strip speed coefficient at the exit of the 4# rolling mill stand is calculated as follows:

[0185] PFX WDG_4 =PFXA4×WDG_X4=PFXA4×FVH5×FVX4

[0186] Among them, PFX WDG_4 It is the strip speed coefficient at the exit of 4# mill stand during the wedging process; PFXA4 is the strip speed coefficient before the wedging at the exit of 4# mill stand; WDG_X4 is the total wedge coefficient of the strip speed at the exit of 4# mill stand; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of 5# mill stand; FVX4 is the wedge adjustment coefficient of the strip speed at the exit of 4# mill stand.

[0187] During the dynamic specification change process, the speed coefficient of the 4# rolling mill stand transmission is calculated as follows:

[0188]

[0189] Among them, PFS WDG_4It is the speed coefficient of 4# mill frame transmission during the wedging process; PFXA4 is the strip speed coefficient before the wedge at the exit of 4# mill frame; WDG_S4 is the total wedge coefficient of the transmission speed of 4# mill frame; SLA4 is the forward slip coefficient before the wedge of 4# mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of 5# mill frame; FVS4 is the wedge adjustment coefficient of the transmission speed of 4# mill frame.

[0190] 1.4# Calculation of speed setting value of rolling mill frame transmission

[0191] During the dynamic specification change process, the speed setting value of the 4# rolling mill frame transmission changes due to the influence of the speed coefficient of the 4# rolling mill frame transmission, and the calculation is as follows:

[0192]

[0193] Among them, VS WDG_4 is the speed setting value of the 4# rolling mill frame transmission during the wedge process; V_MR1 is the exit strip speed setting value of the main speed ramp; PFS WDG 4 It is the speed coefficient of the 4# mill frame transmission during the wedge process; PFXA4 is the strip speed coefficient before the wedge at the exit of the 4# mill frame; SLA4 is the forward slip coefficient before the wedge of the 4# mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# mill frame; FVS4 is the wedge adjustment coefficient of the transmission speed of the 4# mill frame.

[0194] 3. Wedge control of 3# rolling mill stand 6

[0195] Similar to the 4# rolling mill stand, the wedge adjustment coefficients of the inlet strip speed, stand transmission speed and outlet strip speed of the 3# rolling mill stand are calculated as follows:

[0196]

[0197] FVX3=1.0

[0198] Among them, FVH3 is the wedge adjustment coefficient of the strip speed at the entrance of the 3# rolling mill frame; FVS3 is the wedge adjustment coefficient of the transmission speed of the 3# rolling mill frame; FVX3 is the wedge adjustment coefficient of the strip speed at the exit of the 3# rolling mill frame; HNN3 is the strip thickness after the wedge at the entrance of the 3# rolling mill frame; HXN3 is the strip thickness after the wedge at the exit of the 3# rolling mill frame; SLN3 is the forward slip coefficient after the wedge of the 3# rolling mill frame; HNA3 is the strip thickness before the wedge at the entrance of the 3# rolling mill frame, HXA3 is the strip thickness before the wedge at the exit of the 3# rolling mill frame; SLA3 is the forward slip coefficient before the wedge of the 3# rolling mill frame; WDG3 is the wedge coefficient of the 3# rolling mill frame.

[0199] Similarly, the wedge control of the 5# and 4# rolling mill stands indirectly affects the speed of the 3# rolling mill stand. Then, the total wedge coefficient of the inlet strip speed, stand transmission speed and outlet strip speed of the 3# rolling mill stand is calculated as follows:

[0200] WDG_H3=WDG_H4×FVH3=FVH5×FVH4×FVH3

[0201] WDG_S3=WDG_H4×FVS3=FVH5×FVH4×FVS3

[0202] WDG_X3=WDG_H4×FVX3=FVH5×FVH4×FVX3

[0203] Among them, WDG_H3 is the total wedge coefficient of the strip speed at the entrance of the 3# rolling mill frame; WDG_S3 is the total wedge coefficient of the transmission speed of the 3# rolling mill frame; WDG_X3 is the total wedge coefficient of the strip speed at the exit of the 3# rolling mill frame; WDG_H4 is the total wedge coefficient of the strip speed at the entrance of the 4# rolling mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# rolling mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of the 4# rolling mill frame; FVH3 is the wedge adjustment coefficient of the strip speed at the entrance of the 3# rolling mill frame; FVS3 is the wedge adjustment coefficient of the transmission speed of the 3# rolling mill frame; FVX3 is the wedge adjustment coefficient of the strip speed at the exit of the 3# rolling mill frame.

[0204] Then, during the dynamic specification change process, the strip speed coefficient at the exit of the 3# rolling mill stand is calculated as follows:

[0205] PFX WDG_3 =PFXA3×WDG_X3=PFXA3×FVH5×FVH4×FVX3

[0206] Among them, PFX WDG_3 It is the strip speed coefficient at the exit of 3# mill stand during the wedging process; PFXA3 is the strip speed coefficient before the wedge at the exit of 3# mill stand; WDG_X3 is the total wedge coefficient of the strip speed at the exit of 3# mill stand; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of 5# mill stand; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of 4# mill stand; FVX3 is the wedge adjustment coefficient of the strip speed at the exit of 3# mill stand.

[0207] During the dynamic specification change process, the speed coefficient of the 3# rolling mill stand transmission is calculated as follows:

[0208]

[0209] Among them, PFS WDG_3It is the speed coefficient of the 3# mill frame transmission during the wedging process; PFXA3 is the strip speed coefficient before the wedge at the exit of the 3# mill frame; WDG_S3 is the total wedge coefficient of the transmission speed of the 3# mill frame; SLA3 is the forward slip coefficient before the wedge of the 3# mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of the 4# mill frame; FVS3 is the wedge adjustment coefficient of the transmission speed of the 3# mill frame.

[0210] 1.3# Calculation of speed setting value of rolling mill frame transmission

[0211] During the dynamic specification change process, the speed setting value of the 3# rolling mill frame transmission changes due to the influence of the speed coefficient of the 3# rolling mill frame transmission, and the calculation is as follows:

[0212]

[0213] Among them, VS WDG_3 is the speed setting value of the 3# rolling mill frame transmission during the wedge process; V_MR1 is the exit strip speed setting value of the main speed ramp; PFS WDG 3 It is the speed coefficient of the transmission of the 3# rolling mill frame during the wedge process; PFXA3 is the strip speed coefficient before the wedge at the outlet of the 3# rolling mill frame; SLA3 is the forward slip coefficient before the wedge of the 3# rolling mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# rolling mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of the 4# rolling mill frame; FVS3 is the wedge adjustment coefficient of the transmission speed of the 3# rolling mill frame.

[0214] IV. Wedge control of 2# rolling mill stand 5

[0215] Similar to the 4# rolling mill stand 7, the wedge adjustment coefficients of the inlet strip speed, stand transmission speed and outlet strip speed of the 2# rolling mill stand are calculated as follows:

[0216]

[0217] FVX2=1.0

[0218] Among them, FVH2 is the wedge adjustment coefficient of the strip speed at the entrance of the 2# rolling mill frame; FVS2 is the wedge adjustment coefficient of the transmission speed of the 2# rolling mill frame; FVX2 is the wedge adjustment coefficient of the strip speed at the exit of the 2# rolling mill frame; HNN2 is the strip thickness after the wedge at the entrance of the 2# rolling mill frame; HXN2 is the strip thickness after the wedge at the exit of the 2# rolling mill frame; SLN2 is the forward slip coefficient after the wedge of the 2# rolling mill frame; HNA2 is the strip thickness before the wedge at the entrance of the 2# rolling mill frame, HXA2 is the strip thickness before the wedge at the exit of the 2# rolling mill frame; SLA2 is the forward slip coefficient before the wedge of the 2# rolling mill frame; WDG2 is the wedge coefficient of the 2# rolling mill frame.

[0219] Similarly, the wedge control of the 5# rolling mill stand 8, the 4# rolling mill stand 7, and the 3# rolling mill stand 6 indirectly affects the speed of the 2# rolling mill stand 5. Then, the total wedge coefficient of the inlet strip speed, stand transmission speed, and outlet strip speed of the 2# rolling mill stand is calculated as follows:

[0220] WDG_H2=WDG_H3×FVH2=FVH3×FVH4×FVH3×FVH2

[0221] WDG_S2=WDG_H3×FVS2=FVH5×FVH4×FVH3×FVS2

[0222] WDG_X2=WDG_H3×FVX2=FVH5×FVH4×FVH3×FVX2

[0223] Among them, WDG_H2 is the total wedge coefficient of the strip speed at the entrance of the 2# rolling mill frame; WDG_S2 is the total wedge coefficient of the transmission speed of the 2# rolling mill frame; WDG_X2 is the total wedge coefficient of the strip speed at the exit of the 2# rolling mill frame; WDG_H3 is the total wedge coefficient of the strip speed at the entrance of the 3# rolling mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# rolling mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of the 4# rolling mill frame; FVH3 is the wedge adjustment coefficient of the strip speed at the entrance of the 3# rolling mill frame; FVH2 is the wedge adjustment coefficient of the strip speed at the entrance of the 2# rolling mill frame; FVS2 is the wedge adjustment coefficient of the transmission speed of the 2# rolling mill frame; FVX2 is the wedge adjustment coefficient of the strip speed at the exit of the 2# rolling mill frame.

[0224] Then, during the dynamic specification change process, the strip speed coefficient at the exit of the 2# rolling mill stand is calculated as follows:

[0225] PFX WDG_2 =PFXA2×WDG_X2=PFXA2×FVH5×FVH4×FVH3×FVX2

[0226] Among them, PFX WDG_2It is the strip speed coefficient at the exit of 2# mill frame during the wedging process; PFXA2 is the strip speed coefficient before the wedge at the exit of 2# mill frame; WDG_X2 is the total wedge coefficient of the strip speed at the exit of 2# mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of 5# mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of 4# mill frame; FVH3 is the wedge adjustment coefficient of the strip speed at the entrance of 3# mill frame; FVX2 is the wedge adjustment coefficient of the strip speed at the exit of 2# mill frame.

[0227] During the dynamic specification change process, the speed coefficient of the 2# rolling mill stand transmission is calculated as follows:

[0228]

[0229] Among them, PFS WDG_2 It is the speed coefficient of the 2# mill frame transmission during the wedging process; PFXA2 is the strip speed coefficient before the wedge at the exit of the 2# mill frame; WDG_S2 is the total wedge coefficient of the transmission speed of the 2# mill frame; SLA2 is the forward slip coefficient before the wedge of the 2# mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of the 4# mill frame; FVH3 is the wedge adjustment coefficient of the strip speed at the entrance of the 3# mill frame; FVS2 is the wedge adjustment coefficient of the transmission speed of the 2# mill frame.

[0230] 1.2 Calculation of speed setting value of rolling mill frame transmission

[0231] During the dynamic specification change process, the speed setting value of the 2# rolling mill frame transmission changes due to the influence of the speed coefficient of the 2# rolling mill frame transmission, and the calculation is as follows:

[0232]

[0233] Among them, VS WDG_2 is the speed setting value of the 2# rolling mill frame transmission during the wedge process; V_MR1 is the exit strip speed setting value of the main speed ramp; PFS WDG 2 It is the speed coefficient of the 2# mill frame transmission during the wedge process; PFXA2 is the strip speed coefficient before the wedge at the exit of the 2# mill frame; SLA2 is the forward slip coefficient before the wedge of the 2# mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of the 4# mill frame; FVH3 is the wedge adjustment coefficient of the strip speed at the entrance of the 3# mill frame; FVS2 is the wedge adjustment coefficient of the transmission speed of the 2# mill frame.

[0234] 5. Wedge control of 1# rolling mill stand 4

[0235] Similar to the 4# rolling mill stand 7, the wedge adjustment coefficients of the inlet strip speed, stand transmission speed and outlet strip speed of the 1# rolling mill stand are calculated as follows:

[0236]

[0237]

[0238] FVX1=1.0

[0239] Among them, FVH1 is the wedge adjustment coefficient of the strip speed at the entrance of the 1# rolling mill frame; FVS1 is the wedge adjustment coefficient of the transmission speed of the 1# rolling mill frame; FVX1 is the wedge adjustment coefficient of the strip speed at the exit of the 1# rolling mill frame; HNN1 is the strip thickness after the wedge at the entrance of the 1# rolling mill frame; HXN1 is the strip thickness after the wedge at the exit of the 1# rolling mill frame; SLN1 is the forward slip coefficient after the wedge of the 1# rolling mill frame; HNA1 is the strip thickness before the wedge at the entrance of the 1# rolling mill frame, HXA1 is the strip thickness before the wedge at the exit of the 1# rolling mill frame; SLA1 is the forward slip coefficient before the wedge of the 1# rolling mill frame; WDG1 is the wedge coefficient of the 1# rolling mill frame.

[0240] Similarly, the wedge control of the 5# rolling mill stand 8, the 4# rolling mill stand 7, the 3# rolling mill stand 6, and the 2# rolling mill stand 5 indirectly affects the speed of the 1# rolling mill stand. Then, the total wedge coefficient of the inlet strip speed, the stand transmission speed, and the outlet strip speed of the 1# rolling mill stand is calculated as follows:

[0241] WDG_H1=WDG_H2×FVH1=FVH5×FVH4×FVH3×FVH2×FVH1

[0242] WDG_S1=WDG_H2×FVS1=FVH5×FVH4×FVH3×FVH2×FVS1

[0243] WDG_X1=WDG_H2×FVX1=FVH5×FVH4×FVH3×FVH2×FVX1

[0244] Among them, WDG_H1 is the total wedge coefficient of the strip speed at the entrance of the 1# rolling mill frame; WDG_S1 is the total wedge coefficient of the transmission speed of the 1# rolling mill frame; WDG_X1 is the total wedge coefficient of the strip speed at the exit of the 1# rolling mill frame; WDG_H2 is the total wedge coefficient of the strip speed at the entrance of the 2# rolling mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# rolling mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of the 4# rolling mill frame; FVH3 is the wedge adjustment coefficient of the strip speed at the entrance of the 3# rolling mill frame; FVH2 is the wedge adjustment coefficient of the strip speed at the entrance of the 2# rolling mill frame; FVH1 is the wedge adjustment coefficient of the strip speed at the entrance of the 1# rolling mill frame; FVS1 is the wedge adjustment coefficient of the transmission speed of the 1# rolling mill frame; FVX1 is the wedge adjustment coefficient of the strip speed at the exit of the 1# rolling mill frame.

[0245] Then, during the dynamic specification change process, the strip speed coefficient at the exit of the 1# rolling mill stand is calculated as follows:

[0246] PFX WDG_1 =PFXA1×WDG_X1=PFXA1×FVH5×FVH4×FVH3×FVH2×FVX1

[0247] Among them, PFX WDG_1 It is the strip speed coefficient at the exit of 1# mill frame during the wedging process; PFXA1 is the strip speed coefficient before the wedging at the exit of 1# mill frame; WDG_X1 is the total wedge coefficient of the strip speed at the exit of 1# mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of 5# mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of 4# mill frame; FVH3 is the wedge adjustment coefficient of the strip speed at the entrance of 3# mill frame; FVH2 is the wedge adjustment coefficient of the strip speed at the entrance of 2# mill frame; FVX1 is the wedge adjustment coefficient of the strip speed at the exit of 1# mill frame.

[0248] During the dynamic specification change process, the speed coefficient of the 1# rolling mill stand transmission is calculated as follows:

[0249]

[0250] Among them, PFS WDG_1It is the speed coefficient of the transmission of 1# rolling mill frame during the wedging process; PFXA1 is the strip speed coefficient before the wedge at the outlet of 1# rolling mill frame; WDG_S1 is the total wedge coefficient of the transmission speed of 1# rolling mill frame; SLA1 is the forward slip coefficient before the wedge of 1# rolling mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of 5# rolling mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of 4# rolling mill frame; FVH3 is the wedge adjustment coefficient of the strip speed at the entrance of 3# rolling mill frame; FVH2 is the wedge adjustment coefficient of the strip speed at the entrance of 2# rolling mill frame; FVS1 is the wedge adjustment coefficient of the transmission speed of 1# rolling mill frame.

[0251] 1.1# Calculation of speed setting value of rolling mill frame transmission

[0252] During the dynamic specification change process, the speed setting value of the 1# rolling mill frame transmission changes due to the influence of the speed coefficient of the 1# rolling mill frame transmission, and the calculation is as follows:

[0253]

[0254] Among them, VS WDG_1 is the speed setting value of the 1# rolling mill frame transmission during the wedge process; V_MR1 is the exit strip speed setting value of the main speed ramp; PFS WDG 1 It is the speed coefficient of the transmission of the 1# rolling mill frame during the wedge process; PFXA1 is the strip speed coefficient before the wedge at the outlet of the 1# rolling mill frame; SLA1 is the forward slip coefficient before the wedge of the 1# rolling mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# rolling mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of the 4# rolling mill frame; FVH3 is the wedge adjustment coefficient of the strip speed at the entrance of the 3# rolling mill frame; FVH2 is the wedge adjustment coefficient of the strip speed at the entrance of the 2# rolling mill frame; FVS1 is the wedge adjustment coefficient of the transmission speed of the 1# rolling mill frame.

[0255] 2. Calculation of the speed setting value of the transmission of the mill entrance tension roller 2 (0# mill stand)

[0256] When the specification is changed dynamically, the wedge area will not cause the change of strip steel and transmission speed when it reaches the area of ​​the mill entrance tension roller 2, that is, the mill entrance. Therefore, the wedge adjustment coefficients of the mill entrance tension roller 2 entrance strip steel speed, transmission speed and exit strip steel speed are as follows:

[0257] FVH0=1.0

[0258] FVS0=1.0

[0259] FVX0=1.0

[0260] Among them, FVH0 is the wedge adjustment coefficient of the strip speed of the tension roller at the entrance of the rolling mill; FVS0 is the wedge adjustment coefficient of the transmission speed of the tension roller at the entrance of the rolling mill; FVX0 is the wedge adjustment coefficient of the strip speed of the tension roller at the entrance of the rolling mill.

[0261] The wedge control of the mill area indirectly affects the strip and transmission speed at the mill entrance. The total wedge coefficient of the mill entrance tension roller entrance strip speed, transmission speed and exit strip speed is calculated as follows:

[0262] WDG_H0=WDG_H1×FVH0=FVH5×FVH4×FVH3×FVH2×FVH1×FVH0

[0263] WDG_S0=WDG_H1×FVS0=FVH5×FVH4×FVH3×FVH2×FVH1×FVS0

[0264] WDG_X0=WDG_H1×FVX0=FVH5×FVH4×FVH3×FVH2×FVH1×FVX0

[0265] Among them, WDG_H0 is the total wedge coefficient of the strip speed at the entrance of the mill entrance tension roller; WDG_S0 is the total wedge coefficient of the transmission speed of the mill entrance tension roller; WDG_X0 is the total wedge coefficient of the strip speed at the exit of the mill entrance tension roller; WDG_H1 is the total wedge coefficient of the strip speed at the entrance of the 1# mill frame; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of the 4# mill frame; FVH3 is the wedge adjustment coefficient of the strip speed at the entrance of the 3# mill frame; FVH2 is the wedge adjustment coefficient of the strip speed at the entrance of the 2# mill frame; FVH1 is the wedge adjustment coefficient of the strip speed at the entrance of the 1# mill frame; FVH0 is the wedge adjustment coefficient of the strip speed at the entrance of the mill entrance tension roller; FVS0 is the wedge adjustment coefficient of the transmission speed of the mill entrance tension roller; FVX0 is the wedge adjustment coefficient of the strip speed at the exit of the mill entrance tension roller.

[0266] The influence of the rolling mill entrance on the strip thickness can be ignored. It can be considered that the entrance strip speed, frame transmission speed and exit strip speed are completely equal, so we only need to pay attention to the transmission speed coefficient.

[0267] During the dynamic specification change process, the speed coefficient of the mill entrance tension roller transmission is calculated as follows:

[0268]

[0269] Among them, PFSWDG_0 is the speed coefficient of the mill entrance tension roller transmission during the wedging process; PFXA0 is the strip speed coefficient before the wedge at the mill entrance tension roller outlet; WDG_S0 is the total wedge coefficient of the mill entrance tension roller transmission speed; SLA0 is the forward slip coefficient before the wedge of the mill entrance tension roller, which is always 1.0; FVH5 is the wedge adjustment coefficient of the 5# mill frame entrance strip speed; FVH4 is the wedge adjustment coefficient of the 4# mill frame entrance strip speed; FVH3 is the wedge adjustment coefficient of the 3# mill frame entrance strip speed; FVH2 is the wedge adjustment coefficient of the 2# mill frame entrance strip speed; FVH1 is the wedge adjustment coefficient of the 1# mill frame entrance strip speed; FVS0 is the wedge adjustment coefficient of the mill entrance tension roller transmission speed.

[0270] During the dynamic specification change process, the speed setting value of the mill entrance tension roller transmission is affected by the speed coefficient of the mill entrance tension roller transmission and changes, which is calculated as follows:

[0271] VS WDG_0 =V_MR1×PFS WDG_0 =V_MR1×PFXA0×FVH5×FVH4×FVH3×FVH2×FVH1

[0272] Among them, VS WDG_0 is the speed setting value of the mill entrance tension roller transmission during the wedge process; V_MR1 is the exit strip speed setting value of the main speed ramp; PFS WDG_0 It is the speed coefficient of the transmission of the tension roller at the entrance of the rolling mill during the wedging process; PFXA0 is the strip speed coefficient before the wedge at the exit of the tension roller at the entrance of the rolling mill; FVH5 is the wedge adjustment coefficient of the strip speed at the entrance of the 5# rolling mill frame; FVH4 is the wedge adjustment coefficient of the strip speed at the entrance of the 4# rolling mill frame; FVH3 is the wedge adjustment coefficient of the strip speed at the entrance of the 3# rolling mill frame; FVH2 is the wedge adjustment coefficient of the strip speed at the entrance of the 2# rolling mill frame; FVH1 is the wedge adjustment coefficient of the strip speed at the entrance of the 1# rolling mill frame; FVS0 is the wedge adjustment coefficient of the transmission speed of the tension roller at the entrance of the rolling mill.

[0273] Those skilled in the art should understand that the present invention can be implemented in many other specific forms without departing from the spirit and scope of the present invention. Based on the embodiments of the present invention, any changes and modifications made by ordinary technicians in the field of the present invention according to the above disclosure are within the scope of protection of the claims.

Claims

1. A method for controlling the transmission speed during the dynamic specification change process of a cold rolling mill, characterized in that: The method comprises the following steps: S100, determining the speed control wedge adjustment coefficient of each rolling mill stand itself during the dynamic gauge change process: determining the wedge adjustment coefficient of the inlet strip speed of each rolling mill stand, the rolling mill stand transmission speed and the outlet strip speed of the rolling mill stand according to the following wedge setting values ​​including the wedge coefficient of each rolling mill stand, the strip thickness before and after the wedge at the inlet and outlet, the forward slip coefficient before and after the wedge, and the strip speed coefficient before and after the wedge at the outlet; S200, determining the total speed control wedge coefficient of each rolling mill stand during the dynamic specification change process: starting from the last rolling mill stand, reversely calculating the total wedge coefficient of the inlet strip steel speed, the frame transmission speed and the outlet strip steel speed of each rolling mill stand; for the last rolling mill stand, the total wedge coefficient of its inlet strip steel speed, the frame transmission speed and the outlet strip steel speed is determined by the wedge adjustment coefficient of its inlet strip steel speed, the rolling mill frame transmission speed and the rolling mill frame outlet strip steel speed; for the rolling mill stands before the last stage, the total wedge coefficient of its inlet strip steel speed, the frame transmission speed and the outlet strip steel speed is determined by the wedge adjustment coefficient of its inlet strip steel speed, the rolling mill frame transmission speed and the rolling mill frame outlet strip steel speed and the wedge adjustment coefficient of the inlet strip steel speed, the rolling mill frame transmission speed and the rolling mill frame outlet strip steel speed of the subsequent rolling mill stands; S300, determining the transmission speed coefficient of each rolling mill frame according to the strip speed coefficient before the wedge at the exit of each rolling mill frame, the total wedge coefficient of the transmission speed and the forward slip coefficient before the wedge; S400, determine the speed setting value of each rolling mill frame transmission according to the speed coefficient of each rolling mill frame transmission and the outlet strip speed setting value of the main speed ramp, send the speed setting value of each rolling mill frame transmission to the frequency conversion controller of the corresponding transmission, and realize the speed control of each rolling mill frame transmission during the dynamic specification change process through the speed closed-loop control of the frequency conversion controller.

2. The method for controlling the transmission speed during the dynamic specification change process of the cold rolling mill according to claim 1, characterized in that: In step S100, the calculation formula of the wedge adjustment coefficient of the strip speed at the entrance of the final rolling mill frame, the transmission speed of the rolling mill frame and the strip speed at the exit of the rolling mill frame is as follows: Among them, K is the series number of the last rolling mill stand of the multi-stand cold rolling mill, FVH K FVS is the wedge adjustment coefficient of the strip speed at the entrance of the final rolling mill stand; K FVX is the wedge adjustment coefficient of the transmission speed of the final rolling mill stand; K HNN is the wedge adjustment coefficient of the strip speed at the exit of the final rolling mill stand; K HXN is the strip thickness after the wedge at the entrance of the final rolling mill stand; K The strip thickness after the wedge at the exit of the final rolling mill stand; SLN K is the forward slip coefficient of the wedge-shaped stand of the final rolling mill; HNA K HXA is the strip thickness before the wedge at the entrance of the final rolling mill stand; K SLA is the strip thickness before the wedge at the exit of the final rolling mill stand; K PFXA is the slip coefficient before the wedge of the final rolling mill stand; K PFXN is the strip speed coefficient before the wedge at the exit of the final rolling mill stand; K WDG is the strip speed coefficient after the wedge at the exit of the final rolling mill stand; K is the wedge coefficient of the final rolling mill stand; The calculation formula for the wedge adjustment coefficient of the strip speed at the entrance of each stage of the rolling mill stand before the last stage, the transmission speed of the rolling mill stand and the strip speed at the exit of the rolling mill stand is as follows: FVX J =1.0 Where J is the serial number of each rolling mill stand before the last stage of the multi-stand cold rolling mill, ranging from 1 to (K-1), FVH J FVS is the wedge adjustment coefficient of the strip speed at the entrance of each stage of the rolling mill stand before the last stage; J FVX is the wedge adjustment coefficient of the transmission speed of each stage of the rolling mill stand before the last stage; J HNN is the wedge adjustment coefficient of the strip speed at the exit of each stage of the rolling mill stand before the last stage; J The thickness of the strip after the wedge at the entrance of each stage of the rolling mill stand before the last stage; HXN J The thickness of the strip after the wedge at the exit of each stage of the rolling mill stand before the last stage; SLN J HNA is the forward slip coefficient of the wedge-shaped rolling mill stands in front of the last stage; J HXA is the strip thickness before the wedge at the entrance of each stage of the rolling mill stand before the last stage. J SLA is the strip thickness before the wedge at the exit of each stage of the rolling mill stand before the final stage; J WDG is the forward slip coefficient of the wedge-shaped rolling mill stands in front of the last stage; J It is the wedge coefficient of each stage of rolling mill frames before the last stage.

3. The method for controlling the transmission speed during the dynamic specification change process of the cold rolling mill according to claim 2, characterized in that: In step S200, the calculation formula of the total wedge coefficient of the final rolling mill frame entrance strip speed, frame transmission speed and exit strip speed is as follows: WDG_H K =1.0×FVH K =FVH K WDG_S K =1.0×FVS K =FVS K WDG_X K =1.0×FVX K =FVX K Among them, WDG_H K is the total wedge coefficient of the strip speed at the entrance of the final rolling mill stand; WDG_S K is the total wedge coefficient of the transmission speed of the final rolling mill stand; WDG_X K is the total wedge factor of the strip speed at the exit of the final rolling mill stand; The calculation formula for the total wedge coefficient of the inlet strip speed, rack transmission speed and outlet strip speed of each stage of the rolling mill stand before the final stage is as follows: WDG_H J =WDG_H J+1 ×FVH J =FVH K ×FVH K-1 ×…×FVH J+1 ×FVH J WDG_S J =WDG_H J+1 ×FVS J =FVH K ×FVH K-1 ×…×FVH J+1 ×FVS J WDG_X J =WDG_H J+1 ×FVX J =FVH K ×FVH K-1 ×…×FVH J+1 ×FVX J Among them, WDG_H J WDG_S is the total wedge coefficient of the strip speed at the entrance of each stage of the rolling mill stand before the last stage; J is the total wedge coefficient of the transmission speed of each stage of the rolling mill stand before the last stage; WDG_X J It is the total wedge coefficient of the strip speed at the exit of each stage of the rolling mill stands before the last stage.

4. The method for controlling the transmission speed during the dynamic specification change process of the cold rolling mill according to claim 3 is characterized in that: In step S300, the speed coefficient of the final rolling mill frame transmission is calculated as follows: Among them, PFS WDG_K is the speed coefficient of the final mill stand drive during the wedge process; The calculation formula for the speed coefficient of each stage of rolling mill frame transmission before the final stage is as follows: Among them, PFS WDG_J PFXA is the speed coefficient of the rolling mill rack transmission in the wedge process before the final stage; J SLA is the strip speed coefficient before the wedge at the exit of each stage of the rolling mill stand in front of the last stage; J It is the forward slip coefficient in front of the wedge of each stage of rolling mill stands in front of the last stage.

5. The method for controlling the transmission speed during the dynamic specification change process of the cold rolling mill according to claim 4, characterized in that: In step S400, the calculation formula of the speed setting value of the final rolling mill frame transmission is as follows: Among them, VS WDG_K is the speed setting value of the final rolling mill stand transmission in the wedge process; V_MR1 is the exit strip speed setting value of the main speed ramp; The calculation formula for the speed setting value of each stage of the rolling mill frame transmission before the final stage is as follows: Among them, VS WDG_J It is the speed setting value of the rolling mill frame transmission at each stage before the last stage in the wedge process.

6. The method for controlling the transmission speed of a cold rolling mill during dynamic gauge changing according to claim 5, characterized in that: The strip speed coefficient at the outlet of the final rolling mill frame is also determined based on the strip speed coefficient before the wedge at the outlet of the final rolling mill frame and the total wedge coefficient of the outlet strip speed; the speed setting value of the transmission behind the final rolling mill frame is determined based on the strip speed coefficient at the outlet of the final rolling mill frame and the outlet strip speed setting value of the main speed slope, the speed setting value of the transmission behind the final rolling mill frame is sent to the frequency conversion controller of the corresponding transmission, and the speed control of the transmission behind the final rolling mill frame during the dynamic specification change process is realized through the speed closed-loop control of the frequency conversion controller.

7. The method for controlling the transmission speed of a cold rolling mill during dynamic gauge changing according to claim 6, characterized in that: The calculation formula of the strip speed coefficient at the exit of the final rolling mill stand is as follows: PFX WDG_K =PFXA K ×WDG_X K =PFXA K ×FVX K Among them, PFX WDG_K is the strip speed coefficient at the exit of the final mill stand during the wedge process; The calculation formula for the speed setting value of the transmission after the final rolling mill stand is as follows: VX WDG_K =V_MR1×PFX WDG_K =V_MR1×PFXA K ×FVX K Among them, VX WDG_K It is the speed setting value of the transmission after the final rolling mill stand during the wedge process.

8. The method for controlling the transmission speed of a cold rolling mill during dynamic gauge changing according to claim 5, characterized in that: It also includes determining the wedge adjustment coefficient of the inlet strip speed, the transmission speed and the outlet strip speed of the inlet tension roller of the rolling mill during the dynamic gauge change process; Determine the total speed control wedge coefficient of the mill entrance tension roller during the dynamic specification change process: the total wedge coefficient of its entrance strip speed, transmission speed and exit strip speed is determined by the wedge adjustment coefficients of its entrance strip speed, transmission speed and exit strip speed and the wedge adjustment coefficients of the entrance strip speed, mill frame transmission speed and mill frame exit strip speed of the subsequent rolling mill frames respectively; determine the speed coefficient of the mill entrance tension roller transmission according to the strip speed coefficient before the wedge at the exit of the mill entrance tension roller, the total wedge coefficient of the transmission speed and the forward slip coefficient before the wedge; determine the speed setting value of the mill entrance tension roller transmission according to the speed coefficient of the mill entrance tension roller transmission and the exit strip speed setting value of the main speed ramp, send the speed setting value of the mill entrance tension roller transmission to the corresponding transmission frequency converter, and realize the speed control of the mill entrance tension roller transmission during the dynamic specification change process through the speed closed-loop control of the frequency converter.

9. The method for controlling the transmission speed of a cold rolling mill during dynamic gauge changing according to claim 8, characterized in that: The wedge adjustment coefficients of the inlet strip speed, transmission speed and outlet strip speed of the mill inlet tension roller are as follows: FVH0=1.0 FVS0=1.0 FVX0=1.0 Among them, FVH0 is the wedge adjustment coefficient of the strip speed of the entrance tension roller of the rolling mill; FVS0 is the wedge adjustment coefficient of the transmission speed of the entrance tension roller of the rolling mill; FVX0 is the wedge adjustment coefficient of the strip speed of the exit tension roller of the rolling mill; The total wedge coefficient calculation formula of the inlet strip speed, transmission speed and outlet strip speed of the rolling mill entrance tension roller is as follows: WDG_H0=WDG_H1×FVH0=FVH K ×FVH K-1 ×…×FVH J ×…×FVH2×FVH1×FVH0 WDG_S0=WDG_H1×FVS0=FVH K ×FVH K-1 ×…×FVH J ×…×FVH2×FVH1×FVS0 WDG_X0=WDG_H1×FVX0=FVH K ×FVH K-1 ×…×FVH J ×…×FVH2×FVH1×FVX0, where WDG_H0 is the total wedge coefficient of the strip speed at the entrance of the rolling mill tension roller; WDG_S0 is the total wedge coefficient of the transmission speed of the entrance of the rolling mill tension roller; WDG_X0 is the total wedge coefficient of the strip speed at the exit of the entrance of the rolling mill tension roller; The speed coefficient calculation formula of the rolling mill entrance tension roller transmission is as follows: Among them, PFS WDG_0 is the speed coefficient of the mill entrance tension roller transmission during the wedge process; PFXA0 is the strip speed coefficient before the wedge at the mill entrance tension roller outlet; SLA0 is the forward slip coefficient before the wedge at the mill entrance tension roller, which is always 1.0; The calculation formula for the speed setting value of the tension roller transmission at the rolling mill entrance is as follows: VS WDG_0 =V_MR1×PFS WDG_0 =V_MR1×PFXA0×FVH5×FVH4×FVH3×FVH2×FVH1 Among them, VS WDG_0 It is the speed setting value of the mill entrance tension roller drive during the wedge process.

10. The method for controlling the transmission speed during the dynamic gauge changing process of a cold rolling mill according to any one of claims 1 to 9, characterized in that: The cold rolling mill is a five-stand cold rolling mill.

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