Control system of uncoiler brush roll and control method thereof

Abstract

The invention discloses an uncoiler brush roll control system and a control method thereof.The control system comprises automation hardware, a hydraulic system and an execution unit, the hydraulic system is connected to the automation hardware, the execution unit is connected to the automation hardware, a main station of the automation hardware adopts a PN type + CPU, a slave station adopts an IM155-6 PN ST interface module, and the execution unit is connected to the automation hardware. The frequency converter carries out brush roll driving speed regulation, and the communication protocol is ProfiNet and ProfiBus. The invention relates to the field of use of uncoilers, in particular to a control system and a control method for a brush roll of an uncoiler.

Description

Technical Field

[0001] The invention relates to the application field of uncoilers, and in particular to a control system and a control method for a brush roller of an uncoiler. Background Art

[0002] During the flattening process, the strip surface moves downward as the outer diameter of the steel coil decreases, and the operator needs to frequently adjust the working position of the brush roller. The contact range between the brush roller and the strip is unstable when it is manually controlled. The contact area between the brush roller and the strip is small and the contact cleanliness is insufficient. Excessive contact will cause problems such as excessive wear, deformation and falling of the brush hairs, which will reduce the service life of consumable parts and increase the pressure of foreign matter when the brush hairs enter the rough straightening machine with the strip steel, which will have a huge impact on product quality.

[0003] In view of the small contact area between the brush roller and the strip caused by the manual setting of the brush roller height of the existing uncoiler, the contact cleanliness is insufficient, and the excessive contact causes the bristles to be excessively worn, deformed and fallen off. The bristles are rolled with the strip into the rough straightening machine, which increases the pressure of foreign matter. During the leveling process, the linear speed of the brush roller motor on the uncoiler is controlled to be constant relative to the linear speed of the main production line, and the initial position of the brush roller is calculated. After reaching the initial position, the torque of the brush roller motor on the uncoiler is changed to control the upper brush roller cleaning device to follow the position of the strip, so as to achieve constant torque output of the upper brush roller motor and meet the requirement of effectively cleaning the oxide on the steel plate surface. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the height of the brush roller of the uncoiler is manually set, which results in a small contact area between the brush roller and the strip and insufficient contact cleanliness. Excessive contact causes excessive wear, deformation, and falling of the brush bristles.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows: The present invention is a control system for a brush roller of a uncoiler, comprising automation hardware, a hydraulic system and an execution unit, wherein the hydraulic system is connected to the automation hardware, and the execution unit is connected to the automation hardware.

[0006] Furthermore, the automation hardware master station adopts a PN type + CPU, the slave station adopts an IM155-6 PN ST interface module, the frequency converter performs brush roller drive speed regulation, and the communication protocol is ProfiNet and ProfiBus.

[0007] Furthermore, the hydraulic system adopts a servo valve, and newly adds a pressure sensor, an electromagnetic lock valve, and a transition valve body to meet the automatic control requirements of the brush roller on the uncoiler.

[0008] Furthermore, the execution unit adopts a servo valve and a displacement sensor position closed-loop control to improve the movement accuracy of the brush roller, and the brush roller is controlled by a high-performance frequency converter.

[0009] The present invention is a control method for a control system of a brush roller of an unwinding machine, comprising the following steps:

[0010] Step 1: Optimize the brush roller preparation position, calculate the coordinates of point B where the brush roller intersects with the strip when the brush roller is extended in advance, and achieve accurate positioning of the brush roller preparation position;

[0011] Step 2: Inverter and communication control strategy. The inverter control strategy uses vector control. Vector control is a technology that uses inverters to control three-phase AC motors. The basic principle of vector control is to measure and control the stator current vector of the asynchronous motor, and to control the excitation current and torque current of the asynchronous motor according to the magnetic field orientation principle, so as to achieve the purpose of controlling the torque of the asynchronous motor. The master station and the inverter use Profinet protocol communication;

[0012] Step 3: Automatic control strategy and automatic program programming method adopt automatic step control, and control the cylinder pressure through the difference between the real-time torque of the brush roller and the no-load torque; the brush roller CPU communicates unilaterally with the main production line CPU to obtain the key signal of the main production line to complete the protective interlocking of the cylinder; the brush roller speed is set by the set value of the speed difference between the brush roller and the production line in the HMI and the main production line line speed obtained in real time through communication, and the program segment calculates the speed assignment, and adjusts the brush roller working speed according to the slope and speed changes of the main production line to ensure the stable operation of the brush roller;

[0013] Step 4, manual control strategy, manual control controls the rotation and lifting of the brush roller hydraulic cylinder and motor through buttons; manual control program of the brush roller lifting cylinder on the uncoiler, input interface LU is the lower limit of the cylinder stroke, input interface LL is the lower limit of the cylinder, input interface S is the manual action enable command, input interface SV is the current position value when the equipment is manually put into use, input interface CD / CU are the manual cylinder lifting control commands, and the program scanning cycle is integrated with the input interface TA cycle increment, and the cylinder target position is given by the output interface Y to ensure smooth movement under manual cylinder control.

[0014] The beneficial effects achieved by the present invention using the above structure are as follows: after the control program is put into use, according to the on-site usage conditions, the program reliability and control accuracy both meet the design requirements; by monitoring the motor output torque curve, the optimized control system can continuously and stably control the brush force of the brush roller, and excellently complete the cleaning of oxides on the steel plate surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a quality abnormality diagram of the existing product of the present invention;

[0016] Figure 2 This is a comparison diagram of the hardware optimization of the hydraulic system of the present invention;

[0017] Figure 3A network view for configuring the brush roller control system of the present invention;

[0018] Figure 4 This is a geometric diagram of the relationship between the uncoiler area and the strip steel of the present invention;

[0019] Figure 5 This is a geometric diagram of the relationship between the brush roller and the strip steel of the present invention;

[0020] Figure 6 It is a program diagram of data interaction between the master station and the frequency converter of the present invention;

[0021] Figure 7 This is a brush roller control flow chart of the present invention;

[0022] Figure 8 The brush roller linear speed setting program diagram of the present invention;

[0023] Fig. 9 This is a manual control program diagram of the brush roller lifting cylinder of the present invention;

[0024] Fig.10 It is the block diagram of the PID control system of the present invention;

[0025] Fig.11 This is the PID control program diagram of the brush roller cylinder of the present invention;

[0026] Fig.12 This is a disturbance-free switching program diagram when the automatic mode is switched to the manual mode in the present invention.

[0027] Fig.13 This is the torque difference PI adjustment cylinder program diagram of the present invention. DETAILED DESCRIPTION

[0028] Example:

[0029] like Figures 1 to 13 As shown, the present invention is a control system for a brush roller of an unwinding machine, comprising automation hardware, a hydraulic system and an execution unit, wherein the hydraulic system is connected to the automation hardware, and the execution unit is connected to the automation hardware.

[0030] Hydraulic system hardware optimization, such as Figure 2 The proportional valve is replaced with a servo valve, and a pressure sensor, solenoid lock valve, and transition valve body are added to meet the automatic control requirements of the brush roller on the uncoiler.

[0031] Basic automation control system configuration, such as Figure 3 The master station uses Siemens 1512SP-1PN model + CPU, the slave station uses IM155-6 PN ST interface module, Siemens S120 series inverter for brush roller drive speed regulation, and the communication protocol is ProfiNet and ProfiBus.

[0032] The system hardware uses servo valve and displacement sensor position closed-loop control to improve the brush roller movement accuracy. The brush roller uses Siemens S120 high-performance inverter to achieve the best motion control effect. The execution unit optimization items in program control are shown in Table 1.

[0033] Table 1 Execution units in program control after optimization

[0034]

[0035] The present invention is a control method for a control system of a brush roller of an unwinding machine, comprising the following steps:

[0036] Step 1: Optimize the brush roller preparation position, such as Figure 4 , calculate in advance the coordinates of point B where the brush roller intersects with the strip when it is extended, and achieve accurate positioning of the brush roller preparation position;

[0037] Known conditions: Equipment position: (X2, Y2), ∠α, (X4, Y4), (X6, Y6)R2;

[0038] Known: The brush roller cylinder is installed vertically;

[0039] Displacement sensor displacement: M1, M2;

[0040] Obtain the coordinates of the intersection point A: X3 = (X2-M1×sin30°); Y3 = (Y2-M1×cos30°);

[0041] Find the coordinates of the tangent point C through point A and the circle. Figure 5 :

[0042] Establish a coordinate system with point O as the origin;

[0043] PC is the equation of the tangent line of the circle:

[0044] x7x+y7y=R 2 (1)

[0045] P on PC:

[0046] x7x3+y7y3=R 2 (2)

[0047] C is on circle O:

[0048]

[0049] Substituting into (3) we get:

[0050]

[0051] make Substituting into (4) we get:

[0052]

[0053] Using the root-finding formula we get:

[0054]

[0055] (6) Substitution y7 is obtained from the equation, so the coordinates of the tangent point C of a point P outside the circle to the tangent line are:

[0056]

[0057] Combining x=x4 and equation (1), we can find the intersection point M of MN and PC. The coordinates of M are:

[0058]

[0059] ∠CMH=θ

[0060]

[0061]

[0062] The brush roller radius is set to r;

[0063] The coordinates of point Q (intersection position B) are:

[0064]

[0065]

[0066] Step 2: Inverter and communication control strategy. The inverter control strategy uses vector control. Vector control is a technology that uses inverters to control three-phase AC motors. The basic principle of vector control is to measure and control the stator current vector of the asynchronous motor, and to control the excitation current and torque current of the asynchronous motor according to the magnetic field orientation principle, so as to achieve the purpose of controlling the torque of the asynchronous motor. The master station and the inverter use Profinet protocol communication;

[0067] Control word, status word interactive program, such as Figure 6 , call Siemens standard function blocks SFC14 and SFC15 to use Siemens message 220, PZD-10 / 10 to complete data interaction with the slave station;

[0068] Step 3, automatic control strategy, automatic program programming method adopts automatic step sequence control, such as Figure 7As shown, the cylinder pressure is controlled by the difference between the real-time torque of the brush roller and the no-load torque; the brush roller CPU communicates unilaterally with the main production line CPU to obtain the key signal of the main production line to complete the protective interlocking of the cylinder; the brush roller speed is set by the set value of the speed difference between the brush roller and the production line in the HMI and the main production line speed obtained in real time through communication, as shown in FIG. Figure 8 As shown, the program segment calculates the speed value, and adjusts the brush roller working speed according to the slope and speed changes of the main production line to ensure the stable operation of the brush roller;

[0069] Step 4: Manual control strategy: Manual control controls the rotation and lifting of the brush roller hydraulic cylinder and motor through buttons; manual control program of the brush roller lifting cylinder on the uncoiler, such as Fig. 9 , input interface LU is the lower limit of the cylinder stroke, input interface LL is the lower limit of the cylinder, input interface S is the manual action enable command, input interface SV is the current position value when the equipment is manually put into operation, input interfaces CD / CU are respectively the manual lifting and lowering control commands of the cylinder. The program scanning cycle is integrated with the cycle increment of the input interface TA, and the target position of the cylinder is given by the output interface Y to ensure the smooth movement of the cylinder under manual control.

[0070] Runtime Closure Closed-Loop Control Optimization Problem

[0071] like Fig.10 As shown, it forms the control quantity by linearly combining the proportion (P), integral (I), and differential (D) of the deviation e(t) between the given value r(t) and the actual output value c(t), and controls the control object through the actuator.

[0072] The relationship between the output m(t) and input e(t) of the PID controller is shown as follows:

[0073]

[0074] Where Kp is the adjustable proportional coefficient; Ti is the adjustable integral time constant; τ is the differential time constant.

[0075] PI control is a feedback control method based on proportional (P) and integral (I) control. It achieves stable control of the system by adjusting the output of the controller to reduce the deviation between the input and the set value. Compared with the PI controller, the PID controller has an additional differential control component (D), which can provide more precise control performance and response characteristics, eliminate dynamic deviations, reduce oscillations in the control process, and prevent overshoot.

[0076] The relationship between the output m(t) and input e(t) of the PI controller is shown as follows:

[0077]

[0078] Kp is the adjustable proportional coefficient; Ti is the adjustable integral time constant.

[0079] The position closed loop control uses Siemens PID function block FB41 (CONT_C) as follows Fig.11 In addition to basic PID operations, the FB41 function block also provides advanced functions such as integral set value, integral hold, dead zone, and disturbance-free switching (manual to automatic switching).

[0080] It should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A control system for a brush roller of an unwinding machine, characterized in that: It comprises automation hardware, a hydraulic system and an execution unit. The hydraulic system is connected to the automation hardware, and the execution unit is connected to the automation hardware.

2. The control system and control method of the brush roller of the uncoiler according to claim 1, characterized in that: The automation hardware master station adopts PN type + CPU, the slave station adopts IM155-6 PN ST interface module, the frequency converter is used for brush roller drive speed regulation, and the communication protocol is ProfiNet and ProfiBus.

3. The control system and control method of the brush roller of the uncoiler according to claim 1, characterized in that: The hydraulic system adopts a servo valve, and adds a pressure sensor, an electromagnetic lock valve, and a transition valve body to meet the automatic control requirements of the brush roller on the uncoiler.

4. The control system and control method of the brush roller of the uncoiler according to claim 1, characterized in that: The execution unit adopts servo valve and displacement sensor position closed-loop control to improve the movement accuracy of the brush roller, and the brush roller is controlled by a high-performance inverter.

5. A control method for a control system of a brush roller of an unwinding machine, characterized in that: The steps include: Step 1: Optimize the brush roller preparation position, calculate the coordinates of point B where the brush roller intersects with the strip when the brush roller is extended in advance, and achieve accurate positioning of the brush roller preparation position; Step 2: Inverter and communication control strategy. The inverter control strategy uses vector control. Vector control is a technology that uses inverters to control three-phase AC motors. The basic principle of vector control is to measure and control the stator current vector of the asynchronous motor, and to control the excitation current and torque current of the asynchronous motor according to the magnetic field orientation principle, so as to achieve the purpose of controlling the torque of the asynchronous motor. The master station and the inverter use Profinet protocol communication; Step 3: Automatic control strategy and automatic program programming method adopt automatic step control, and control the cylinder pressure through the difference between the real-time torque of the brush roller and the no-load torque; the brush roller CPU communicates unilaterally with the main production line CPU to obtain the key signal of the main production line to complete the protective interlocking of the cylinder; the brush roller speed is set by the set value of the speed difference between the brush roller and the production line in the HMI and the main production line line speed obtained in real time through communication, and the program segment calculates the speed assignment, and adjusts the brush roller working speed according to the slope and speed changes of the main production line to ensure the stable operation of the brush roller; Step 4, manual control strategy, manual control controls the rotation and lifting of the brush roller hydraulic cylinder and motor through buttons; manual control program of the brush roller lifting cylinder on the uncoiler, input interface LU is the lower limit of the cylinder stroke, input interface LL is the lower limit of the cylinder, input interface S is the manual action enable command, input interface SV is the current position value when the equipment is manually put into use, input interface CD / CU are the manual cylinder lifting control commands, and the program scanning cycle is integrated with the input interface TA cycle increment, and the cylinder target position is given by the output interface Y to ensure smooth movement under manual cylinder control.

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