Control method for realizing rotation positioning of large-inertia equipment
Through multi-step precise calculation and control, the coordination problem of position and speed control in the rotational positioning of large cold rolling equipment was solved, realizing high precision and stable operation of the equipment, and improving production efficiency and product quality.
Patent Information
- Application Number
- CN202511026283.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-24
- Publication Date
- 2025-11-07
AI Technical Summary
Traditional control methods are difficult to effectively coordinate the relationship between position control and speed control during the rotational positioning process of large cold rolling equipment, resulting in inaccurate positioning speed, overshoot, and poor dynamic response, which affects the stability of equipment operation and positioning accuracy, and consequently affects product quality and production efficiency.
Through multi-step calculations including position proportional control, positioning speed proportional control, integral calculation, amplitude limiting processing, and first-order delay unit, the motion parameters of the equipment are precisely controlled. A first-order delay unit and differential controller are designed to optimize dynamic response and stability, thereby achieving precise rotational positioning.
It improves the accuracy and stability of rotational positioning for high-inertia equipment, ensuring that the equipment can quickly and accurately reach the target position, thereby enhancing the reliability of equipment operation and production efficiency.
Smart Images
Figure CN120901091A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of cold rolling electric control, and particularly relates to a control method for realizing rotation positioning of a large-inertia device. BACKGROUND
[0002] In cold rolling production, rotation positioning of large devices is a core technical link for guaranteeing product quality and production efficiency. Compared with small and medium-sized devices, large cold rolling devices (such as rolling mill racks, coiling machines, uncoiling machines, flying shears, etc.) have the characteristics of large volume, high inertia, heavy load, and difficult positioning, and their rotation positioning needs to consider both dynamic response speed and running stability.
[0003] A typical large cold rolling device needing rotation positioning is arranged as shown in the figure Figure 1 The working roller 1 is driven to rotate by the motor 2 coaxially connected or connected through a gear box, a detection encoder 3 arranged at the end of the motor 2 is used to calculate the rotation speed of the motor 2 and the rotation position of the working roller 1, and a positioning proximity switch 4 arranged at the shaft end of the working roller 1 is used for initial position determination of rotation positioning.
[0004] The traditional control method is difficult to effectively coordinate the relationship between position control and speed control when processing rotation positioning of large inertia devices. In the positioning process, there are problems such as inaccurate positioning speed control, easy overshoot, and poor dynamic response, which leads to poor device running stability, the positioning precision cannot meet the needs of high-precision cold rolling production, and further affects the product quality and production efficiency of the strip steel. SUMMARY
[0005] The purpose of the present application is to provide a control method for realizing rotation positioning of a large inertia device, which can at least solve some defects in the prior art.
[0006] To achieve the above purpose, the present application adopts the following technical solutions:
[0007] A control method for realizing rotation positioning of a large inertia device, comprising the following processes:
[0008] S1, obtaining an actual position value and a set position value of the working roller, and calculating a positioning speed pre-control value through position proportional control;
[0009] S2, calculating a positioning acceleration through positioning speed proportional control according to the calculated positioning speed pre-control value;
[0010] S3, performing integral operation on the positioning acceleration to convert the accumulation of acceleration with time into a positioning speed set value;
[0011] S4, limiting the positioning speed set value to limit it within the allowed positioning speed range;
[0012] S5, smoothing the limited positioning speed setting value through a first-order delay unit and outputting;
[0013] S6, calculating the positioning torque pre-control value according to the smoothed positioning speed setting value.
[0014] Further, in the step S1, the calculation process of the positioning speed pre-control value is as follows: , wherein Vpre is the positioning speed pre-control value, KP1 is the position control proportional gain, WS is the set position value, and XS is the actual position value of the work roll.
[0015] Further, in the step S1, the positioning speed pre-control value is also limited, so that the positioning speed pre-control value is limited within the allowed positioning speed range.
[0016] Further, in the step S2, the calculation process of the positioning acceleration is as follows: , wherein A is the positioning acceleration, KP2 is the acceleration proportional gain, Vpre is the positioning speed pre-control value, and VP is the actual set value of the positioning speed.
[0017] Further, in the step S2, the positioning acceleration is also limited, so that the positioning acceleration is limited within the allowed positioning acceleration range.
[0018] Further, in the step S3, the integral operation process of the positioning acceleration is as follows: , wherein VP N is the positioning speed setting value of the current period, VP N-1 is the positioning speed setting value of the previous period, A N is the positioning acceleration of the current period, TA is the program scanning period, and TI is the integral time constant.
[0019] Further, in the step S4, the calculation process of the limiting of the positioning speed setting value is as follows: , wherein, is the limiting value of the positioning speed setting, is the difference between the actual position value and the set position value of the work roll, K0 is the gain of the parabolic function, and K1 is the limit of the parabolic change rate.
[0020] Further, in the step S5, the calculation process of the smoothing of the limited positioning speed setting value is as follows: , wherein V N is the smoothed output value of the positioning speed setting value of the current period, V N-1 is the smoothed output value of the positioning speed setting value of the previous period, TA is the program scanning period, and TG1 is the time constant of the first-order inertia link; VP NThe positioning speed set value of the current cycle is set.
[0021] Further, in the step S5, the first-order delay unit comprises a first-order delay element PT1 for setting a point delay and a first-order delay element PT2 for simulating the time constant of the current controller; and in the step S6, the positioning torque pre-control value is calculated from the positioning speed set value after smoothing processing extracted from the output signal of the first-order delay element PT1.
[0022] Further, in the step S6, the calculation process of the positioning torque pre-control value is as follows: ; wherein, TQ N is the positioning torque pre-control value of the current cycle, TQ N-1 is the positioning torque pre-control value of the previous cycle, V N is the smoothing output value of the positioning speed set value of the current cycle, TA is the program scanning cycle, TI is the integral time constant, and KP2 is the acceleration proportional gain.
[0023] Compared with the prior art, the beneficial effects of the present application are:
[0024] (1) The present application can effectively improve the positioning accuracy of large inertia equipment through precise calculation and control in multiple steps, from position proportional control to positioning torque pre-control, and can meet the strict requirements of high-precision application scenarios such as cold rolling production on the positioning accuracy of the equipment.
[0025] (2) In the control process, the present application effectively solves the instability problem of the system when approaching the target position by introducing an offset value K1 through the positioning speed set value limiting link, and at the same time, the current is adjusted in advance during acceleration and braking by calculating the positioning torque pre-control value, which effectively intervenes the speed and power output of the equipment. Through the cooperation of these measures, the overshoot of the actual position value is largely avoided, so that the equipment can accurately and smoothly reach the target position, and the reliability and stability of the equipment operation are improved.
[0026] (3) The present application can reasonably set the delay time of the first-order delay unit, the differential time of the differential controller and other key parameters, and optimize the dynamic response by using the time delay unit and the feedforward pre-control, so that the equipment can quickly and stably respond to the control instruction and achieve good dynamic response.
[0027] (4) The application effectively solves the instability problem of the system in the low speed section by introducing the offset value K1 in the positioning speed setting value limiting link, and a first order delay unit is designed to smooth the speed, which reduces the influence of sudden change of speed on the equipment, and the complete position-speed-current three closed loop control architecture of the whole control system is formed, each link cooperates and restricts each other, which effectively improves the stability of the whole control system, and guarantees the long-term stable operation of the equipment in complex production environment.
[0028] The application will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS
[0029] Figure 1 is a typical device schematic diagram of the existing large inertia equipment rotary positioning;
[0030] Figure 2 is a control method flow schematic diagram of the rotary positioning of the large inertia equipment in the embodiment of the application;
[0031] Figure 3 is a control principle schematic diagram of the positioning control in the embodiment of the application;
[0032] Figure 4 is a linkage adjustment principle schematic diagram of the positioning control and the motor variable frequency control in the embodiment of the application.
[0033] The reference signs are explained as follows: 1, work roll; 2, motor; 3, detection encoder; 4, positioning proximity switch. DETAILED DESCRIPTION
[0034] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.
[0035] In the description of the application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the application.
[0036] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, can also be abutment connection or integral connection; for those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0037] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features; in the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.
[0038] In the conventional rotation positioning of large inertia equipment, it is difficult to effectively coordinate the relationship between position control and speed control, and at the same time, in the positioning process, there are problems such as inaccurate positioning speed control, easy overshoot and poor dynamic response, which leads to poor equipment operation stability, the positioning precision cannot meet the demand of high-precision cold rolling production, and further affects the product quality and production efficiency of the strip steel.
[0039] To solve at least one of the technical problems existing in the related art, as shown in Figure 2 and Figure 3 The present application provides a control method for realizing rotation positioning of large inertia equipment, comprising:
[0040] Step S1, obtaining the actual position value and the set position value of the work roll, and calculating the positioning speed pre-control value through position proportional control.
[0041] Step S2, calculating the positioning acceleration through positioning speed proportional control according to the calculated positioning speed pre-control value.
[0042] Step S3, performing integral operation on the positioning acceleration, and converting the accumulation of acceleration with time into a positioning speed set value.
[0043] Step S4, limiting the positioning speed set value to make the positioning speed set value limited within the allowed positioning speed range.
[0044] Step S5, performing smoothing processing and outputting on the limited positioning speed set value through a first-order delay unit.
[0045] Step S6, calculating the positioning torque pre-control value according to the smoothed positioning speed set value.
[0046] According to the actual position value and the set position value of the work roll, the position proportional control, the positioning speed proportional control, the first-order delay unit and the like are used to calculate the positioning speed set value of the motor in the rotation positioning process and the positioning torque pre-control value in the positioning acceleration and deceleration process, so that the system quickly and stably approaches the target position, and the contradiction between the small deviation oscillation and the slow response / overload is solved by the non-linear link and the pre-control.
[0047] In some embodiments, the positioning speed pre-control value calculated by the position proportional control in step S1 can be realized in the following manner: the actual position of the work roll is obtained by position detection coding, and the positioning speed pre-control value is calculated according to the difference between the set position and the actual position and the position control proportional gain.
[0048] Wherein, when the work roll needs to be rotated and positioned, the work roll is first rotated at a certain fixed speed by the motor drive, the detection signal of the positioning approach switch arranged at the shaft end of the work roll is used as the positioning start mark, the pulse increment of the motor shaft end detection encoder is accumulated from zero, and the actual position of the work roll is calculated by multiplying the unit pulse length of the detection encoder, and the calculation formula is as follows: Wherein, XS is the actual position value of the work roll, I is the number of pulses accumulated from the detection signal of the positioning approach switch arranged at the shaft end of the work roll, and Li is the length of the unit pulse of the detection encoder [mm / pulse].
[0049] Specifically, the calculation process of the positioning speed pre-control value is as follows: positioning starts, the actual position value and the set position value of the work roll are obtained, the difference between the two is calculated, and the difference is multiplied by the position control proportional gain, that is, Wherein, Vpre is the positioning speed pre-control value, KP1 is the position control proportional gain, WS is the set position value, and XS is the actual position value of the work roll.
[0050] The refined KP1 value determination process is as follows: first, KP1 is preliminarily determined according to the maximum allowable speed V_Lim of the device and the maximum possible position deviation AS_max, to ensure that the speed pre-control value does not exceed V_Lim at the maximum position deviation, that is: KP1≤V_Lim / AS_max; then, a smaller KP1 (such as 50% of the calculated value) is initially set during debugging optimization, to ensure that there is no obvious impact or overshoot when the device starts, and KP1 is gradually increased while monitoring the positioning process, if the device approaches the target position and "overshoots" (the actual position exceeds the set position), it indicates that KP1 is too large and needs to be appropriately reduced, if the speed increases slowly during the positioning process and it takes too long to reach the target position, it indicates that KP1 is too small and needs to be appropriately increased, until the appropriate KP1 value is adjusted. For large inertia devices (such as rolling mill stands and coilers), inertia is large, KP1 needs to be appropriately reduced (to avoid inertia impact caused by sudden speed change), and if the load fluctuation of the device is large (such as the thickness of the strip steel), KP1 can be appropriately reduced to improve stability.
[0051] Preferably, in order to ensure safety, the positioning speed pre-control value can be limited in amplitude, and the positioning speed pre-control value is limited in the allowable positioning speed range by setting the positioning speed limit V_Lim.
[0052] In this step, by adjusting parameters KP1 and V_Lim, the highest rotational speed before and after positioning and the positioning deceleration point can be adjusted, the corresponding positioning speed pre-control value is calculated according to the rotation characteristics of different devices, to provide a basis for subsequent accurate control.
[0053] In some embodiments, in step S2, the positioning acceleration calculated by the positioning speed proportional control can be realized in the following way: the positioning acceleration is calculated according to the difference between the positioning speed pre-control value and the positioning speed actual set value, and the positioning speed control proportional gain; wherein the positioning speed actual set value is the positioning speed set value after the integral operation of the positioning acceleration in the previous period.
[0054] Specifically, the calculation process of the positioning acceleration is as follows: according to the difference between the positioning speed pre-control value and the positioning speed actual set value calculated in step S1, and combined with the positioning speed control proportional gain, the positioning acceleration is calculated, that is Wherein, A is the positioning acceleration, KP2 is the acceleration proportional gain, Vpre is the positioning speed pre-control value, and VP is the positioning speed actual set value.
[0055] The refined KP2 value determination process is as follows: first, KP2 is preliminarily determined according to the maximum allowed acceleration A_Lim of the device and the maximum speed deviation ΔV_max (the maximum possible difference between Vpre and VP), to ensure that the maximum acceleration does not exceed A_Lim, that is, KP2≤A_Lim / ΔV_max, wherein ΔV_max can be estimated according to the speed fluctuation range of the device during normal operation (such as 10%-20% of Vpre); then, a smaller KP2 (such as 60% of the calculated value) is initially set during debugging and optimization to avoid excessive acceleration causing impact, and KP2 is gradually increased, and the speed tracking effect is observed; if the speed curve (actual speed VP) appears "sawtooth fluctuation" or the device runs with obvious vibration, it means that KP2 is too large and needs to be appropriately reduced; if the actual speed VP lags behind the pre-control value Vpre for a long time (such as slow speed increase during acceleration), it means that KP2 is too small and needs to be appropriately increased, until the appropriate KP2 value is adjusted.
[0056] Preferably, the positioning acceleration is also limited in amplitude, and the positioning acceleration is limited within the allowed positioning acceleration range by setting the positioning speed limit A_Lim.
[0057] In this step, by adjusting the parameters KP2 and A_Lim, the positioning acceleration can be adjusted to realize accurate calculation and control of the acceleration required for the change of the positioning speed of the device.
[0058] In some embodiments, in step S3, the positioning acceleration is integrated to convert the accumulation of acceleration over time into the positioning speed set value, complete the conversion from acceleration control to speed control, and enable the device speed to change according to the expected law. Specifically, the positioning acceleration integration operation process is as follows: , wherein VP N is the positioning speed set value of the current period, VP N-1 is the positioning speed set value of the previous period, A N is the positioning acceleration of the current period, TA is the program scanning period, and TI is the integration time constant.
[0059] For the amplitude limiting of the positioning speed set value, in the prior art, a parabolic formula is generally used to calculate the amplitude limiting value of the positioning speed set value, that is, However, when the position error between the actual position value of the work roll and the set position value is close to zero, the slope of tends to infinity, which may cause system instability; therefore, in the present embodiment, when the position error is close to zero, the amplitude limiting value of the positioning speed set value is calculated by the following formula: , wherein A_Lim is the maximum allowed acceleration of the device. When approaching zero, an offset value K1 is introduced to avoid system instability caused by infinite slope of the root difference value, make the slope reach zero, realize more fine limiting of the positioning speed setting value, and ensure smooth change of the speed of the device when approaching the target position.
[0060] Specifically, the calculation process of limiting the positioning speed setting value is as follows: , wherein, is the limiting value of the positioning speed setting, is the difference between the actual position value and the set position value of the work roll, K0 is the gain of the parabolic function, and K1 is the limit of the parabolic rate. When the position error approaches zero, , at this time the result approaches zero, and the slope (speed change rate) also becomes zero, thereby eliminating the instability caused by the infinite slope.
[0061] Specifically, the determination principle of K0 is that K0 needs to match the maximum speed V_Lim allowed by the device and the maximum position deviation , to ensure that the speed limiting value does not exceed the safety upper limit at the maximum deviation, while taking into account the dynamic response; according to the parabolic limiting formula, when the position deviation is the maximum possible value , the speed limiting should approach the maximum positioning speed V_Lim allowed by the system (to avoid early speed limiting affecting the response), that is: , ignoring the small value (because K1 is usually much smaller than ), and simplifying to: .
[0062] The determination principle of K1 is that K1 needs to ensure that the position deviation approaches 0, the speed limiting smoothly approaches zero, and avoid oscillation at a low speed segment (when the deviation is small), and the value needs to match the minimum stable speed of the device; when approaches 0, the system needs to maintain the minimum stable speed V_min (the lowest speed at which the device does not oscillate), at this time , because is very small (close to 0), , square both sides of the formula and ignore the high-order small terms to obtain , and simplify to .
[0063] In some embodiments, the calculation process of smoothing the limited positioning speed setting value in step S5 is as follows: ; wherein, V N is the smoothed output value of the positioning speed setting value of the current period, and V N-1Smoothed output value of positioning velocity set value of previous cycle, TA is program scanning cycle, TG1 is time constant of first order inertia link; VP N Positioning velocity set value of current cycle.
[0064] In an optimized embodiment, the designed first order delay unit includes two first order delay elements PT1 and PT2, wherein the first order delay element PT1 is used for setting point delay, corresponding to 4xSigma of symmetrical optimized velocity controller, and the first order delay element PT2 is used for equivalent time constant of analog current controller, ensuring consistent control chain time constant, thereby smoothing the positioning velocity set value, reducing sudden change of velocity, and improving equipment operation stability. The limited positioning velocity set value is processed by PT1 and PT2, and then used as positioning set velocity of positioning controller, and the actual velocity of motor is subtracted, so as to adjust the velocity controller, as shown in the following formula. Figure 4
[0065] In some embodiments, in step S6, the positioning torque pre-control value is calculated from the smoothed positioning velocity set value extracted from the output signal of the first order delay element PT1.
[0066] Optionally, the calculation process of the positioning torque pre-control value in the embodiment can be completed by means of the differential controller DT1, and the specific calculation formula is as follows: ; wherein, TQ N Positioning torque pre-control value of current cycle, TQ N-1 Positioning torque pre-control value of previous cycle, V N Smoothed output value of positioning velocity set value of current cycle, TA is program scanning cycle, TI is integral time constant, and KP2 is acceleration proportional gain.
[0067] In this process, the step of extracting the smoothed positioning velocity set value from the output signal of the first order delay element PT1 can eliminate high frequency noise or sudden change in the original set value, avoid system oscillation or mechanical impact caused by sharp change of velocity command, and further extract the differential (i.e. acceleration information) of the velocity set value through differential operation of the differential controller DT1, so as to compensate the delay caused by system inertia in advance, and realize "feedforward control".
[0068] As shown in the following formula. Figure 4 As shown, the positioning torque pre-control value output by the positioning controller (i.e. the positioning torque pre-control value calculated by means of the differential controller DT1) is superimposed into the set value of the torque ring in the motor vector control as a torque preset value to regulate the torque controller, so that the dynamic demand of the inertial load can be compensated in advance, and the adjustment time of the feedback control is reduced. During the acceleration and braking of the equipment, the pre-control can be used to adjust the current in advance, accelerate the control process, while effectively avoiding the overshoot of the actual position value, so that the equipment can quickly and accurately reach the target position.
[0069] The above examples are only illustrative of the present application and do not constitute a limitation on the scope of protection of the present application. Any design identical or similar to the present application falls within the scope of protection of the present application.
Claims
1. A control method for achieving rotational positioning of a large inertia device, characterized by, The method comprises the following steps: S1, obtaining the actual position value and the set position value of the work roll, and calculating the positioning speed pre-control value through position proportional control; S2, calculating the positioning acceleration through positioning speed proportional control according to the calculated positioning speed pre-control value; S3, performing integral operation on the positioning acceleration to convert the accumulation of the acceleration with time into a positioning speed set value; S4, limiting the positioning speed set value to make the positioning speed set value limited in the allowed positioning speed range; S5, performing smoothing processing on the limited positioning speed set value through a first-order delay unit and outputting the same; S6, calculating the positioning torque pre-control value according to the smoothed positioning speed set value.
2. The control method of claim 1, wherein In the step S1, the calculation process of the positioning speed pre-control value is as follows: Vpre=KP1 (WS-XS), wherein Vpre is the positioning speed pre-control value, KP1 is the position control proportional gain, WS is the set position value, and XS is the actual position value of the work roll.
3. The control method of claim 1 or 2, wherein In the step S1, the positioning speed pre-control value is also limited to make the positioning speed pre-control value limited in the allowed positioning speed range.
4. The control method of claim 1, wherein In the step S2, the calculation process of the positioning acceleration is as follows: Wherein, A is the positioning acceleration, KP2 is the acceleration proportional gain, Vpre is the positioning speed pre-control value, and VP is the positioning speed actual set value.
5. The control method of claim 1 or 4, wherein In the step S2, the positioning acceleration is also limited to make the positioning acceleration limited in the allowed positioning acceleration range.
6. The control method of claim 1, wherein The positioning acceleration integral operation process in step S3 is as follows: where VP N is the positioning velocity set value of the current period, VP N-1 is the positioning velocity set value of the previous period, A N is the positioning acceleration of the current period, TA is the program scanning period, and TI is the integral time constant.
7. The control method of claim 1, wherein The step S4 is to limit the calculation process of the positioning speed setting value as follows: wherein, is the limiting value of the positioning speed setting, is the difference between the actual position value and the setting position value of the work roll, K0 is the gain of the parabolic function, and K1 is the limit of the parabolic variation rate.
8. The control method of claim 1, wherein The calculation process of the step S5 for smoothing the limited positioning speed setting value is as follows: ; where V N is the smoothed output value of the positioning velocity set value for the current cycle, V N-1 is the smoothed output value of the positioning velocity set value for the previous cycle, TA is the program scan cycle, TG1 is the time constant of the first order inertia link; VP N is the positioning velocity set value for the current cycle.
9. The control method of claim 1, wherein In the step S5, the first-order delay unit comprises a first-order delay element PT1 for setting point delay and a first-order delay element PT2 for simulating the equivalent time constant of a current controller; and in the step S6, the positioning torque pre-control value is calculated from the smoothed positioning speed set value extracted from the output signal of the first-order delay element PT1.
10. The control method of claim 1, wherein In the step S6, the calculation process of the positioning torque pre-control value is as follows: ; wherein, TQ N is the positioning torque pre-control value of the current period, TQ N-1 is the positioning torque pre-control value of the previous period, V N is the smoothing output value of the positioning speed setting value of the current period, TA is the program scanning period, TI is the integral time constant, and KP2 is the acceleration proportional gain.