CN112828052B - An online evaluation method for tension roll slip based on cold strip rolling - Google Patents

Abstract

The invention provides an on-line evaluation method for tension roll slippage based on cold rolling of strip steel, belonging to the technical field of cold rolling steel. The method first collects the relevant data of the tension roller motor in real time, automatically finds the effective trend interval of the data, intercepts the time period when the trend changes, captures the abnormal adjustment area of the tension roller parameters, then establishes an automatic evaluation model of tension roller slip, and finally displays the operation of the tension roller motor online. Condition and Tension Roller Slip Model Evaluation Results. The invention realizes the evaluation of the tension roller slip phenomenon in each tension section during the production of the cold rolling production line by monitoring the state of the tension roller and the changes of the relevant parameters in real time, capturing the abnormal parameter adjustment area, establishing the tension roller slippage evaluation model, and making qualitative and quantitative judgments. The evaluation results can play a guiding role in the regulation and control of on-site operators, analyze the area where the slip occurs in time, improve product quality and reduce the loss of production equipment.

Description

An online evaluation method for tension roll slip based on cold strip rolling

technical field

The invention relates to the technical field of cold rolling steel, in particular to an on-line evaluation method for the slippage of tension rolls based on cold rolling of strip steel.

Background technique

The tension roll is an important part of the cold rolling plant. The modern cold rolling production process is continuous and high-speed production. The strip must maintain a certain tension to run continuously. The tension in the cold rolling production line is generated because the rolling stock is stretched, resulting in elastic deformation. The tension control is provided by the open-loop and closed-loop control of the speed and torque of the tension roller motor inverter. The function of tension control is: to make the tension of each tension section within the range specified by the production process; to ensure that the position of the strip in production is kept accurate; to a certain extent, to improve the uneven version of the strip; to make the strip obtain uniform zinc coating. However, due to the specifications of incoming materials, the roughness of the roller surface, the running state of the motor, etc., it is possible that the tension roller will slip. The slipping phenomenon will not only cause defects in the surface quality of the strip, but also bring about the deviation of the strip, etc. Serious production failure will pose a threat to the safety of production equipment, aggravate the surface wear of the roll itself, make the surface roughness of the roll drop significantly in a short period of time, and reduce the roll change cycle. In actual production, it is very difficult to monitor the slipping phenomenon in real time, because the slippage often occurs in an instant, and a slight degree of slippage will not cause downtime and other consequences, and it is difficult to be detected by the monitoring system and on-site production personnel. It will have an impact on product quality and production equipment, and the number of tension rolls in the cold rolling production line is huge, and it is unrealistic to rely on real-time monitoring by manpower. Therefore, it is necessary to evaluate whether the tension roller slips through the model and to output feedback in time.

At present, most of the research on tension roller slip is about how to control the torque of the roller motor or change the material structure of the tension roller to reduce or eliminate the slip phenomenon, but there is almost no evaluation of a general tension roller slip phenomenon. For example, Patent No. 201911346564.X "A Method for Eliminating Slippage of Tension Roller Group", which mainly describes the adjustment of the tension at the entrance of the tension roller, and the control of the tension roller from slipping by reducing the sliding coefficient of the tension roller. Patent No. 201810528066.6 "Anti-slip Tension Roller" discloses an anti-slip tension roller, which is suitable for wet steel strip conditions to ensure the reliable operation of the cold rolling mill and improve the service life of the tension roller.

The invention proposes a method based on quantitative analysis of the two parameters of the motor torque and the linear speed of the tension roller to qualitatively evaluate whether the tension roller has slippage.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide an on-line evaluation method for tension roll slippage based on strip cold rolling, which can qualitatively and quantitatively analyze the relevant parameters of the tension roll motor, capture the abnormal adjustment interval of the parameters, establish an evaluation model for tension roll slippage, and evaluate the tension. Roller slip phenomenon, the results play a guiding role in the regulation and control of on-site production personnel, timely analyze the area where slip occurs, improve product quality and reduce production equipment loss.

The method first collects the relevant data of the tension roller motor in real time, automatically finds the effective trend interval of the data, intercepts the time period when the trend changes, captures the abnormal adjustment area of the tension roller parameters, then establishes an automatic evaluation model of tension roller slip, and finally displays the operation of the tension roller motor online. Condition and Tension Roller Slip Model Evaluation Results.

The specific steps are as follows:

(1) Collect the relevant data of the tension roller in real time;

(2) Automatically find the effective trend interval of data;

(3) Intercept the time period when the trend changes;

(4) Capture the abnormal adjustment area of tension roller parameters;

(5) Establish an automatic evaluation model for tension roller slip;

(6) Online display of the running state of the tension roller motor and the evaluation results of the tension roller slip model.

The parameters of the tension roller in step (4) are the linear speed v _L of the tension roller and the actual torque value T _A of the motor of the tension roller.

The tension roller related data in step (1) includes the tension roller linear speed v _L , the actual torque value T _A of the tension roller motor, and the sampling frequency collected in real time in step (1) is 100ms. The line speed v _L is the actual value of the line speed of the tension roller, and the actual torque value T _A is the current actual torque value fed back by the inverter.

In step (2), the data points of the linear velocity v _L and the actual torque T _A are collected and stored in real time with 100ms as the sampling frequency, and the sampled data is filtered by the fixed step size judgment method to find the effective trend of the data. The difference between the data point and the currently sampled data point is compared with the fixed step size to judge whether it is a valid trend. The trend set is t _i ={t _{i_up} ,t _{i_down} ,t _{i_invalid} }:

In the above formula, t _vi is the change trend of the linear speed of the tension roller, t _Ti is the change trend of the motor torque of the tension roller, C _v is the fixed step size of the line speed, C _T is the fixed step size of the torque, and v _Li is the sampled tension roller Current line speed, v _Li+1 is the linear speed of the tension roller at the next sampling point, T _Ai is the current actual torque value of the tension roller motor sampled, and T _Ai+1 is the actual torque value of the tension roller motor at the next sampling point ; t _{vi_ rise} is the rising trend of the actual value of the tension roller linear speed, which is an effective trend; t _{vi_ decline} is the decreasing trend of the actual value of the tension roller linear speed, which is an effective trend; t _{vi_ invalid} is the invalid change of the actual value of the tension roller linear speed Trend; t _{Ti_ rises} is the rising trend of the current torque actual value of the tension roller motor, which is an _effective trend; t _{Ti_ decreases} , which is the downward trend of the current torque actual value of the tension roller motor, which is an effective trend; The current torque actual value is invalid trend. The method of intercepting the time period in which the trend changes in step (3) is: continuously calculate the change trends t _vi and t _Ti of the sampled data, and use the torque T _A as a reference parameter to record the time interval Y in which the trend of the _torque parameter changes. _Moment as the time period during which the trend has changed.

The method of capturing the abnormal adjustment area of tension roller parameters in step (4) is to record the time period Y _torque in which the trend of torque T _A changes. The segment is the abnormal adjustment area of the tension roller motor parameters, and the algorithm is:

which is:

Among them, Y _error is the abnormal adjustment time period of the motor parameters of the tension roller, v _{L_s , v L_e are} the data points of the linear speed at the beginning and the end of the tension roller in the abnormal adjustment time period; T _{A_s} , T _{A_e} are the abnormal adjustment time period Inner roller motor start torque and end torque data points.

Within the abnormal adjustment time Y _error of the tension roller motor parameters, the tension roller slip evaluation model is used to quantitatively calculate the actual value of the tension roller motor torque T _A and the linear speed v _L ; the tension roller slip evaluation model is as follows, where 0 means normal, 1 Represents a slip:

Here, E _i represents the evaluation of the state of the tension roller.

The beneficial effects of the above-mentioned technical solutions of the present invention are as follows:

In the above scheme, it is possible to accurately evaluate whether the tension roller slips or not. In order to verify the accuracy of the determination method of the present invention, a determination experiment was carried out in a 2230mm cold-rolled galvanizing plant, the torque and line speed data of three groups of tension roller motors were collected in real time, and the relevant parameters of each group of tension rollers were calculated by the evaluation method of the present invention. Bringing into the model evaluation, the judgment results are basically consistent with the actual situation on site.

Description of drawings

Fig. 1 is the flow chart of the method of the present invention;

Fig. 2 is the actual curve diagram of the slippage of the tension roller in the method of the present invention;

FIG. 3 is a diagram showing the results of the evaluation of the slippage of the tension roller according to the method of the present invention.

Detailed ways

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, detailed description will be given below with reference to the accompanying drawings and specific embodiments.

The invention provides an on-line evaluation method for the slippage of tension rolls based on cold rolling of strip steel.

As shown in Figure 1, this method first collects the relevant data of the tension roller motor in real time, automatically finds the effective trend interval of the data, intercepts the time period when the trend changes, captures the abnormal adjustment area of the tension roller parameters, and then establishes an automatic evaluation model for the tension roller slip. Online display of tension roller motor running state and tension roller slip model evaluation results.

The method specifically includes the following steps:

S1, data collection: according to the sampling frequency of 100ms, real-time collection of the actual torque T _A and the linear speed v _L of the tension rollers in the cold rolling production line when the tension rollers are running.

S2, automatically find the valid data interval: use the fixed step size judgment method to filter the sampled data to find the change trend of the valid data, and compare the result with the fixed step size by making the difference between the data points sampled at the next moment and the data points currently sampled , to judge the effective trend, the trend set is t _i ={t _{i_up} ,t _{i_down} ,t _{i_invalid} }:

In the above formula, t _vi is the change trend of the linear speed of the tension roller, t _Ti is the change trend of the motor torque of the tension roller, C _v is the fixed step size of the linear speed parameter, C _T is the fixed step size of the torque parameter, and v _Li is the sampling The data point of the current linear speed of the tension roller, v _Li+1 is the data point of the linear speed of the tension roller at the next sampling time, T _Ai is the data point of the current actual torque of the tension roller motor sampled, and T _Ai+1 is the data point of the tension roller at the next sampling time The actual torque parameter point of the motor, the fixed step C can be adjusted according to the parameter specifications and sampling frequency of different roller motor inverters.

S3, the method of intercepting the time period in which the trend changes is: continuously calculate the change trends t _vi and t _Ti of the sampled data, take the torque T _A as a reference parameter, and record the time interval Y _torque in which the torque parameter trend changes as the trend The time period in which the change occurred.

S4, capture the abnormal adjustment area of the tension roller motor related parameters: record the time period Y _torque when the trend of the torque T _A changes, if in this time period, the two parameters have opposite trends, it is determined that this time period is the tension roller Motor parameter abnormal adjustment time, the algorithm is:

which is:

Among them, Y _error is the abnormal adjustment time period of the motor parameters of the tension roller, v _{L_s , v L_e are} the data points of the linear speed at the beginning and the end of the tension roller in the abnormal adjustment time period; T _{A_s} , T _{A_e} are the abnormal adjustment time period Inner roller motor start torque and end torque data points.

S5, use the tension roller slip evaluation model to output the evaluation result: within the abnormal adjustment time Y _err or of the tension roller motor parameters, use the tension roller slip evaluation model to quantitatively calculate the tension roller motor torque T _A and the linear speed v _L. The tension roller slip evaluation model is as follows, where 0 represents normal and 1 represents slip:

Here, E _i represents the evaluation of the state of the tension roller.

S6, online display of the running state of the roller motor and the evaluation result of the tension roller slip: the running state of each tension roller motor and the evaluation result of the tension roller state are displayed on the host computer interface in real time.

Further, in the fixed step size judgment method, the fixed step lengths C _v and C _T are determined based on the on-site sampling period and the specifications of the tension roller motor and frequency converter. In the tension roller slip evaluation model, the state evaluation V _i The threshold of 20% is determined by the production line production process.

The following description will be given in conjunction with specific embodiments.

Example 1

An on-line evaluation method for the slippage of a cold-rolled tension roll comprises the following steps:

S1 data collection: According to the sampling frequency of 100ms, the linear speed of each tension roller and the actual torque data of the roller drive motor are collected respectively.

In the embodiment of the present invention, the tension straightening section is taken as an example, and the relevant data of the 1#, 2#, and 3# roller motors of the 8# tension roller groups are taken to evaluate the slippage of the tension rollers. As shown in Table 1, the torque and linear speed data of each roller motor 3s of the 8# tension roller group in the tension straightening section in a certain period of time were collected.

Table 1

S2 and S3, determine the change trend of motor parameters in the sampling time period by the fixed step size judgment method, and intercept the data points in the time period where the trend changes, as shown in Table 2:

Table 2

S4, determine the change trend of the motor parameters in the sampling time period by the fixed step size judgment method, and capture the abnormal adjustment interval of the motor parameters of the tension roller according to the process of Figure 1. The judgment results are shown in Table 3:

table 3

S5, judge the abnormal adjustment range of motor parameters through the above process, establish a tension roller slip evaluation model, and bring the data into the evaluation model. The matching tension roller slip results are shown in Table 4:

Table 4

Abnormal adjustment equipment v_L adjustment range T_A adjustment range Slip Evaluation Tension roller motor 1# 24.2% 58.6% 1. Slip

Figure 2 and Figure 3 show the actual curve and evaluation results of the tension roller slip, respectively.

The invention determines the abnormal state adjustment interval of the roller motor by monitoring the linear speed of each tension roller and the torque of the roller motor in real time in the tension section of cold rolling, and performs qualitative and quantitative analysis on the data points in the interval through the slip evaluation model, so as to realize the detection of tension rollers. Evaluation of the slip state. This method is a highly versatile and highly reliable tension roll slip evaluation method. It has been tried on a domestic 2230mm cold-rolled galvanizing production line. The evaluation results are basically consistent with the actual situation on site. sex.

The above is the preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can be made. These improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (4)

1. an on-line evaluation method for the slippage of tension rollers based on cold rolling of strip steel, is characterized in that: comprise the steps as follows: (1) Collect tension roller related data in real time; tension roller related data include tension roller linear speed v _L , tension roller motor torque actual value T _A ; (2) Automatically find the effective trend interval of the data, use the fixed step size judgment method to filter the data collected in step (1), find the effective trend of the data, and make a difference between the data points sampled at the next moment and the data points currently sampled , the result is compared with the fixed step size to judge whether it is an effective trend; (3) Intercept the time period when the trend changes; (4) Capture the abnormal adjustment time period of the motor parameters of the tension roller; (5) Establish an automatic evaluation model for tension roller slip; (6) Online display of the running state of the tension roller motor and the evaluation results of the automatic evaluation model of tension roller slip; The step (2) trend set is t _i ={t _{i_ rises} , t _{i_ falls} , t _{i_ is invalid} }:

In the above formula, t _vi is the change trend of the linear speed of the tension roller, t _Ti is the change trend of the motor torque of the tension roller, C _v is the fixed step size of the line speed, C _T is the fixed step size of the torque, and v _Li is the sampled tension roller Current line speed, v _Li+1 is the linear speed of the tension roller at the next sampling point, T _Ai is the current actual torque value of the tension roller motor sampled, and T _Ai+1 is the actual torque value of the tension roller motor at the next sampling point ; t _{vi_ rise} is the rising trend of the actual value of the tension roller linear speed, which is an effective trend; t _{vi_ decline} is the decreasing trend of the actual value of the tension roller linear speed, which is an effective trend; t _{vi_ invalid} is the invalid change of the actual value of the tension roller linear speed Trend; t _{Ti_ rises} is the rising trend of the current torque actual value of the tension roller motor, which is an _effective trend; t _{Ti_ decreases} , which is the downward trend of the current torque actual value of the tension roller motor, which is an effective trend; The current torque actual value invalid trend; The method for capturing the abnormal adjustment time period of the tension roller motor parameters in the step (4) is to record the time period Y _torque in which the actual value of the tension roller motor torque T _A trend changes. If there is an opposite trend, it is determined that this period of time is the period of abnormal adjustment of the motor parameters of the tension roller. The algorithm is:

which is:

Among them, Y _error is the abnormal adjustment time period of the motor parameters of the tension roller, v _{L_s , v L_e are} the data points of the linear speed at the beginning and the end of the tension roller in the abnormal adjustment time period; T _{A_s} , T _{A_e} are the abnormal adjustment time period The data points of the torque at the beginning and the end of the inner tension roller motor; In the step (5), within the abnormal adjustment time period Y _error of the tension roller motor parameters, use the tension roller slip automatic evaluation model to quantitatively calculate the tension roller motor torque actual value T _A and the linear speed v _L ; the tension roller slip automatic evaluation The model is as follows, where 0 means normal and 1 means slipping:

Here, E _i represents the evaluation of the state of the tension roller. 2 . The on-line evaluation method for tension roll slippage based on cold strip rolling according to claim 1 , wherein the sampling frequency collected in real time in the step (1) is 100 ms. 3 . 3. the on-line evaluation method of tension roller slip based on strip steel cold rolling according to claim 1, is characterized in that: described tension roller linear velocity v _L is tension roller linear speed actual value, tension roller motor torque actual value T _A is the current actual torque value fed back by the inverter. 4. the on-line evaluation method of tension roll slippage based on strip cold rolling according to claim 1, is characterized in that: the method for intercepting the time period in which the trend changes in the step (3) is: continuously calculate the tension of the sampling data The change trend of the roller linear speed t _vi and the change trend of the tension roller motor torque t _Ti , the actual value of the tension roller motor torque T _A is used as a reference parameter, and the time period Y _rotation of the change in the trend of the actual value of the tension roller motor torque T _A is recorded. _Moment as the time period during which the trend has changed.

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