A distributed electromagnetic edge pressing device and its control system

Abstract

The present invention relates to the field of stamping processing technology, and more specifically, to a distributed electromagnetic edge clamping device and its control system. The present invention divides the area according to the actual processing requirements of the target workpiece and designs a distributed electromagnetic edge clamping device; and based on the force data obtained in real time, through an independent charging and demagnetizing circuit, the working current is controlled based on PID PWM, and the electromagnetic force of each edge clamping area is adjusted to meet the edge clamping requirements of the target workpiece, effectively improving the accuracy and reliability of the stamping process and ensuring the forming quality of the stamped parts. The present invention takes into account the characteristics of soft magnets, and determines whether the soft magnets are in a residual magnetism by monitoring whether the preset edge clamping force changes in the previous and next cycles have the same change trend, and adjusts the working current direction accordingly, thereby ensuring the accurate adjustment of the electromagnetic force, solving the problem that the distributed electromagnetic edge clamping device may have residual magnetism after power failure, resulting in untimely adjustment of the electromagnetic force.

Description

Technical Field

[0001] The present invention relates to the field of stamping processing technology, and more specifically, to a distributed electromagnetic edge holding device and a control system thereof. Background Art

[0002] Most current stamping methods rely on a press with telescopic components, such as hydraulic rods, to drive the upper and lower dies, bringing the workpiece into contact with the punch. For one thing, components like hydraulic rods are bulky, requiring significant installation space. Furthermore, the die design integrates both punching and blanking forces, making this approach unsuitable if the workpiece requires a different blanking force.

[0003] The inventors subsequently divided the blank holding device into regions according to the actual processing requirements of the target workpiece, obtaining a distributed electromagnetic blank holding device, thereby separating the punching force and the blank holding force, and using a blank holding device based on electromagnetic design to provide the blank holding force.

[0004] When controlling the distributed electromagnetic edge clamping device, it was found that since the electromagnetic force of the electromagnet is adjusted based on the soft magnetic material: when a larger electromagnetic force is needed, a larger current can be passed to increase the electromagnetic force; if a smaller electromagnetic force is needed, a smaller current can be passed, the power can be turned off, or a current in the opposite direction can be passed.

[0005] However, after power failure, the soft magnetic material may have residual magnetism. If it is not possible to accurately determine whether the soft magnetic material is in the residual magnetism stage, it will affect the timing of current control, and then affect the adjustment of the electromagnetic force (that is, the actual clamping force), affecting the quality of the final product - wrinkling and cracking are likely to occur. Summary of the Invention

[0006] Based on this, it is necessary to provide a distributed electromagnetic edge pressing device and its control system to address the problem that residual magnetism may exist after the distributed electromagnetic edge pressing device is powered off, resulting in untimely adjustment of the electromagnetic force.

[0007] The present invention is achieved by adopting the following technical solutions:

[0008] In a first aspect, the present invention discloses a distributed electromagnetic edge clamping device for performing edge clamping on a target workpiece having M target areas.

[0009] The distributed electromagnetic edge pressing device includes: an electromagnetic chuck, M charging and demagnetization circuits, and a pressed plate.

[0010] An electromagnetic chuck is disposed on a surface of an upper mold facing a target workpiece; M edge-holding regions are provided on the electromagnetic chuck for performing zoned edge-holding on the target workpiece; magnetic poles are provided in the edge-holding regions; the M edge-holding regions are isolated from each other by magnetic yokes; and the distribution of the M edge-holding regions is determined according to the processing requirements of the target workpiece; wherein the mth edge-holding region is used to perform edge-holding on the mth target region of the target workpiece; m∈[1,M]. The mth charging and demagnetization circuit is connected to the magnetic poles of the mth edge-holding region for providing an operating current to the mth edge-holding region; and a pressed plate is used to be attracted by the electromagnetic chuck and clamp the target workpiece between the pressed plate and the electromagnetic chuck.

[0011] The electromagnetic chuck moves with the upper die and acts on the punch, and controls the electromagnetic force in real time to complete the edge pressing of the target workpiece.

[0012] The electromagnetic force control method includes the following steps:

[0013] S1, obtain the actual blank holding force of the mth target area at the current time t(n) The working current of the mth edge pressure region at the current time t(n) According to the preset blank holding force curve C of the mth blank holding area m , get the preset blank holding force corresponding to the current time t(n)

[0014] S2, calculate the error at the current time t(n) Based on e m (n) The working current of the mth pressure edge region at the next moment t(n+1) Perform PID-based PWM control and then control the electromagnetic force;

[0015] Among them, if Determine the preset blank holder force change dF in the current cycle n , the preset blank holder force change dF in the previous cycle n-1 Whether they have the same trend of change; is the preset blank holding force corresponding to the previous moment t(n-1); is the preset blank holding force corresponding to the next moment t(n+1);

[0016] If dF n 、dF n-1 have the same trend of change, then Otherwise, keep The direction remains unchanged.

[0017] The distributed electromagnetic edge holding device is implemented according to the method or process of the embodiment of the present disclosure.

[0018] In a second aspect, the present invention discloses a control system for a distributed electromagnetic edge holding device, which is used to control the distributed electromagnetic edge holding device disclosed in the second aspect.

[0019] The distributed electromagnetic edge pressing control system includes: a data acquisition module and a controller.

[0020] The data acquisition module includes a pressure acquisition submodule and a current acquisition submodule. The pressure acquisition submodule is set in M ​​target areas and is used to collect the actual blank holding force of the mth target area at the current time t(n). The current acquisition submodule is set in the M charging and demagnetization circuits to collect the working current of the mth pressure edge area at the current time t(n) m∈[1,M].

[0021] The controller is used to obtain the actual blank holding force on the mth target area at the current time t(n) The working current of the mth edge pressure region at the current time t(n) According to the preset blank holding force curve C of the mth blank holding area m , get the preset blank holding force corresponding to the current time t(n) Calculate the error at the current time t(n) Based on e m (n) The working current of the mth pressure edge region at the next moment t(n+1) Perform PID-based PWM control and then control the electromagnetic force; if Determine the preset blank holder force change dF in the current cycle n , the preset blank holder force change dF in the previous cycle n-1 Whether they have the same trend of change; is the preset blank holding force corresponding to the previous moment t(n-1); is the preset blank holder force corresponding to the next moment t(n+1); if dF n 、dF n-1 have the same trend of change, then Otherwise, keep The direction remains unchanged.

[0022] The control system of the distributed electromagnetic edge holding device is implemented according to the method or process of the embodiment of the present disclosure.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention divides the target workpiece into regions according to the actual processing requirements and designs a distributed electromagnetic edge clamping device. Based on the force data obtained in real time, the working current is controlled by PID-based PWM through an independent charging and demagnetizing circuit to adjust the electromagnetic force of each edge clamping area to meet the edge clamping requirements of the target workpiece, effectively improving the accuracy and reliability of the stamping process and ensuring the forming quality of the stamped parts.

[0025] 2. The present invention takes into account the characteristics of soft magnets. By monitoring whether the change in the preset blank holding force in the previous and subsequent cycles has the same change trend, it is determined whether the soft magnet is in the residual magnetism state, and the direction of the working current is adjusted accordingly, thereby ensuring accurate adjustment of the electromagnetic force.

[0026] 3. The present invention also considers the adjustment of PID gain parameters. By monitoring whether the absolute value of the difference between the actual blank holder force derivatives before and after the cycle is greater than the preset minimum change value δ, it is determined whether the PID gain parameter needs to be adjusted to adaptively provide an appropriate integral coefficient K. d , thus ensuring precise control of PWM. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of a distributed electromagnetic edge holding device in Example 1 of the present invention;

[0028] Figure 2 for Figure 1 Schematic diagram of the electromagnetic chuck;

[0029] Figure 3 for Figure 1 Schematic diagram of the mid-charge and demagnetization circuit;

[0030] Figure 4 for Figure 1 Flow chart of electromagnetic force control of distributed electromagnetic edge holding device;

[0031] Figure 5 Schematic diagram of PID-based PWM control in Example 1 of the present invention;

[0032] Figure 6 for Figure 4 Flowchart for judging whether the working current is commutated and whether the PID gain parameters are adjusted;

[0033] Figure 7 This is a schematic diagram of a control system of a distributed electromagnetic edge holding device in Example 2 of the present invention. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component. When a component is considered to be "fixed to" another component, it may be directly fixed to the other component or there may be a central component.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] Example 1

[0038] See also Figure 1 , Figure 1 Schematic diagram of a distributed electromagnetic edge clamping device in the present invention. The distributed electromagnetic edge clamping device is used to clamp a target workpiece having M target areas.

[0039] The distributed electromagnetic edge pressing device includes: an electromagnetic chuck, M charging and demagnetization circuits, and a back pressure plate.

[0040] The electromagnetic chuck is arranged on the side of the upper mold facing the target workpiece. Figure 2 The electromagnetic chuck is provided with M edge-holding regions for performing edge-holding on a target workpiece in sections. Magnetic poles are provided within each edge-holding region. The M edge-holding regions are isolated from each other by magnetic yokes. The distribution of the M edge-holding regions is determined based on the machining requirements of the target workpiece; the mth edge-holding region is used to hold the mth target region of the target workpiece. m∈[1,M].

[0041] In this embodiment 1, the target workpiece is a door-like component, which has 7 target areas (B1-B7), that is, M = 7. Of course, different target workpieces have different processing requirements, and the number and location of target areas are also different, and the distribution of the edge holding areas is also adjusted accordingly.

[0042] For the M charging and demagnetization circuits, the m-th charging and demagnetization circuit is connected to the magnetic pole of the m-th edge pressure region, so as to provide the operating current to the m-th edge pressure region.

[0043] It should be noted that the magnetic poles need to be powered to generate electromagnetic force. For different edge pressure areas, the number of magnetic poles may be different, and the operating voltage and current may also be different. Of course, if the number of magnetic poles in the edge pressure area is the same, the same operating voltage can also be set. Among them, the voltage corresponding to a single magnetic pole is U0, and the voltage of the mth edge pressure area B m The number of magnetic poles is N m , that is, the mth edge pressure region B m The operating voltage is UB m =U0×N m .

[0044] In this embodiment 1, B1, B4 and B6 have the same number of magnetic poles, and B5 and B7 have the same number of magnetic poles. Therefore, the edge pressure areas with the same requirements can be connected in parallel to the same power supply.

[0045] See Figure 3 The mth charging and demagnetization circuit includes a power module U m , solid-state relay KS m , diode Z m , resistor 1 Resistor 2 Intermediate relay KA m .

[0046] Among them, U m , KS m , Z m 、 The first circuit is formed; the magnetic pole of the mth edge pressure region, KA m 、 KS m Form the second circuit.

[0047] KS m Used to control the input or disconnection of the magnetic pole working current in the mth pressure edge area; KA m Used to control the direction of the magnetic pole working current in the mth edge pressure region.

[0048] Specifically, KS m Open, the mth charging and demagnetizing circuit is connected, and the magnetic pole of the mth edge pressure area is energized; KS m Close, the mth charging and demagnetization circuit is disconnected, and no power is supplied to the magnetic pole in the mth edge pressure area.

[0049] In KS m Open case, KA mSwitch to one side, and the mth charging and demagnetizing circuit passes a positive working current to the magnetic pole of the mth pressure edge region; KA m Switching to one side, the mth charging and demagnetization circuit passes a reverse working current to the magnetic pole of the mth pressure edge region.

[0050] The pressed plate is used to be adsorbed by the electromagnetic chuck, and the target workpiece is clamped between the pressed plate and the electromagnetic chuck.

[0051] It should be noted that the upper die can be driven by an existing drive member such as a hydraulic press. In this way, the electromagnetic chuck moves with the upper die and acts on the punch, and controls the electromagnetic force in real time to complete the edge pressing of the target workpiece.

[0052] Among them, see Figure 4 , the electromagnetic force control method comprises the following steps:

[0053] S1, obtain the actual blank holding force of the mth target area at the current time t(n) The working current of the mth edge pressure region at the current time t(n) According to the preset blank holding force curve C of the mth blank holding area m , get the preset blank holding force corresponding to the current time t(n)

[0054] It should be noted that the preset blank holder force curve C m It can be obtained by statistical means through experiments or by calculation through simulation. m Reflects the preset blank holder force The ideal change of the current moment t(n). Real-time control of the blank holder force is actually to change the actual blank holder force Keep as close to the preset blank holder force as possible

[0055] Due to the actual blank holding force Working current This is the actual measured value. When the target workpiece does not touch the punch below, the punching has not actually started. Therefore, it is also necessary to obtain the distance L between the target workpiece and the punch at the current time t(n) n If L n If the distance is less than or equal to the threshold, it means that the target workpiece is about to contact the punch below, and the magnetic pole of the mth edge holding area is passed through. Generate electromagnetic force.

[0056] Of course, if L n If the distance is greater than the threshold, it means that there is still some time before the target workpiece contacts the punch below. In this case, there is no need to pass current into the blank holding area, and no electromagnetic force will be generated in the blank holding area.

[0057] S2, calculate the error at the current time t(n) Based on e m (n) The working current of the mth pressure edge region at the next moment t(n+1) PID-based PWM control is performed to control the electromagnetic force.

[0058] Among them, see Figure 5 , the principle of PID-based PWM control is:

[0059] e m (n) is the input, and the duty cycle is calculated by the PID (proportional, integral, and differential) link to output the PWM signal u to the mth charging and demagnetization circuit. m (n), u m (n) is restricted to 1 or 0, depending on u m The value of (n) in turn controls the electromagnetic force.

[0060] Right now: Where K p is the proportionality coefficient, K i is the differential coefficient, K d is the integral coefficient; e m (n-1) represents the error of the previous moment t(n-1); T represents the interval between the current moment t(n) and the previous moment t(n-1).

[0061] Among them, K p , K i and K d The PID gain parameter is used to adjust the weight of each control item. By adjusting these parameters, the response speed, stability and anti-interference ability of the PID can be adjusted.

[0062] If u m (n) = 0, the mth charging and demagnetizing circuit is disconnected, and no power is supplied to the magnetic pole of the mth edge pressure region (i.e., KS is closed). m ); if u m (n) = 1, then the mth charging and demagnetizing circuit is connected, and the magnetic pole of the mth pressure edge region is energized (i.e., KS is turned on). m ).

[0063] Since the possible existence of residual magnetism is reflected in the primary indicator of the monitoring level,

[0064] See Figure 6 ,like Also determine the preset blank holder force change dF for the current cycle n , the preset blank holder force change dF in the previous cycle n-1 Whether they have the same changing trend.

[0065] in, is the preset blank holding force corresponding to the previous moment t(n-1); It is the preset blank holding force corresponding to the next moment t(n+1).

[0066] If dF n 、dF n-1 have the same trend of change, then To switch direction (ie switch KA m ); otherwise, keep The direction remains unchanged (i.e., KA is not switched m ).

[0067] In general, the basis for judging whether the circuit is commutating can be expressed by the formula:

[0068]

[0069] like dF n *dF n-1 >0, then Otherwise, keep The direction remains unchanged.

[0070] Of course, after the mth target area is pressed, the mth pressing area is first demagnetized, and then the mth charging and demagnetization circuit is disconnected. This ensures the safety and stability of the system.

[0071] Based on the above control method, timely judgment of residual magnetism is made to ensure accurate adjustment of electromagnetic force. In combination with the distributed electromagnetic blanking operation, the forming quality of stamping parts can be guaranteed.

[0072] In addition, in the above control method, the PID gain parameter (i.e. K p , K i , K d ) are preset values, typically obtained experimentally. While the resulting stamped parts meet the required tolerances, in practice, due to variations in the workings of soft magnetic materials, the preset PID gain parameters are not optimal, and the precision of the stamped parts can be further improved.

[0073] Therefore, this embodiment 1 also discloses another electromagnetic force control method, the steps of which are the same as the above control method, except that:

[0074] In S2,

[0075] Also determine the actual blank holder force derivative of the current cycle The actual blank holder force derivative of the previous cycle Is the absolute value of the difference greater than the preset minimum change value δ? is the actual blank holding force applied to the mth target area at the previous moment t(n-1); is the operating current of the mth edge pressure region at the previous moment t(n-1)

[0076] like The integral coefficient K in the PID gain parameter d Otherwise, keep the PID gain parameters unchanged.

[0077] Specifically, the minimum change value δ is generally set to a larger value greater than zero, such as 70.

[0078] like Indicates that there is an oscillation error.

[0079] For the actual blank holding force The actual blank holding force curve D m , that is, there is a trend of impending shock.

[0080] Then we need to d Make adjustments, K d The adjustment method is:

[0081] K d Adjusting the initial value from 0 to 0.1, that is, increasing the differential gain, can effectively suppress the oscillation of the curve. This is because increasing the differential gain introduces a moderate differential effect, making the system more sensitive to the error change rate, thereby reducing the oscillation amplitude of the system.

[0082] It should be noted that an excessively large K d This may cause the system to be overly sensitive, thereby introducing over-amplified noise and interference, leading to system instability or undesirable responses, such as repeated oscillations or increased oscillation amplitude. d A value of 0.1 is a suitable value.

[0083] After the oscillation error is eliminated, the subsequent D m Return to the preset blank holder force curve C m On the other hand, K d Adjust back to the original size, that is, the initial value 0.

[0084] Of course, if Description D m with C m The fit is very high, and the existing PID gain parameters have a good control effect. Keeping the PID gain parameters unchanged does not require adjustment.

[0085] By adjusting the PID gain parameters, the working current is adjusted synchronously. Adjust the size for more precise control.

[0086] Example 2

[0087] This embodiment 2 discloses a control system for a distributed electromagnetic edge holding device, which is used to control the distributed electromagnetic edge holding device disclosed in embodiment 1.

[0088] See Figure 7 In this embodiment 2, the power module U m These are placed in a power cabinet and are used to power M charging and demagnetization circuits. Specifically, due to the presence of some shared power modules, the cabinet contains four power modules: module 1 powers B2; module 2 powers B5 and B7; module 3 powers B1, B4, and B6; and module 4 powers B3.

[0089] In general, the control system of the distributed electromagnetic edge holding device includes: a data acquisition module and a controller.

[0090] The data acquisition module is the internal sensor and includes a pressure acquisition submodule and a current acquisition submodule.

[0091] The pressure acquisition submodule is set in M ​​target areas and is used to collect the actual blank holding force of the mth target area at the current time t(n) Generally, the pressure acquisition submodule uses a pressure sensor.

[0092] The current acquisition submodule is set in the M charging and demagnetization circuits to collect the working current of the mth pressure edge area at the current time t(n) Generally, the current acquisition submodule uses a current sensor.

[0093] Of course, the data acquisition module may also include a distance acquisition submodule. The distance acquisition submodule is provided on the upper die and is used to measure the distance between the target workpiece and the punch. Generally, the distance acquisition submodule uses a displacement sensor.

[0094] The controller can be an independent machine such as an industrial computer, or an integrated component such as a chip. In this embodiment 2, the controller is an industrial computer, which is connected to the data acquisition module through an acquisition card and transmits signals to the M charging and demagnetization circuits through an output card.

[0095] The controller is used to:

[0096] 1. Obtain the actual blank holding force on the mth target area at the current time t(n) The working current of the mth edge pressure region at the current time t(n) According to the preset blank holding force curve C of the mth blank holding area m , get the preset blank holding force corresponding to the current time t(n) Calculation error Based on e m The working current of the mth pressure edge region at the next moment t(n+1) Perform PID-based PWM control and then control the electromagnetic force; if Determine the preset blank holder force change dF in the current cycle n , the preset blank holder force change dF in the previous cycle n-1 Whether they have the same trend of change; is the preset blank holding force corresponding to the previous moment t(n-1); is the preset blank holder force corresponding to the next moment t(n+1); if dF n 、dF n-1 have the same trend of change, then Otherwise, keep The direction remains unchanged.

[0097] 2. Get the distance L between the target workpiece and the punch at the current time t(n) n ; If L n If the distance is less than or equal to the threshold, the magnetic pole of the mth edge pressure region is introduced.

[0098] 3. Determine the actual blank holder force derivative of the current cycle The actual blank holder force derivative of the previous cycle Whether the absolute value of the difference is greater than the preset minimum change value δ;

[0099] in, is the actual blank holding force applied to the mth target area at the previous moment t(n-1); is the operating current of the mth edge pressure region at the previous moment t(n-1)

[0100] like The integral coefficient K in the PID gain parameter d Make adjustments to eliminate the oscillation error; otherwise, keep the PID gain parameters unchanged.

[0101] Example 3

[0102] This embodiment 3 discloses a readable storage medium, in which computer program instructions are stored. When the computer program instructions are read and executed by a processor, the steps of the distributed electromagnetic edge pressing control method of embodiment 1 are executed.

[0103] When the method of Example 1 is applied, it can be applied in the form of software, such as a program designed to be independently run on a computer-readable storage medium, where the computer-readable storage medium can be a USB flash drive, and the USB flash drive is designed to start the program of the entire method through an external trigger.

[0104] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0105] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A distributed electromagnetic edge holding device, characterized in that: It is used to perform edge pressing on a target workpiece having M target areas; The distributed electromagnetic edge holding device comprises: An electromagnetic chuck is provided on a side of the upper mold facing the target workpiece; the electromagnetic chuck is provided with M edge-holding regions for performing edge-holding of the target workpiece in sections; magnetic poles are provided in the edge-holding regions; the M edge-holding regions are isolated from each other by magnetic yokes; the distribution of the M edge-holding regions is set according to the processing requirements of the target workpiece; wherein the mth edge-holding region is used to perform edge-holding of the mth target region of the target workpiece; m∈[1,M]; M charging and demagnetization circuits; wherein the m-th charging and demagnetization circuit is connected to the magnetic pole of the m-th edge pressure region, and is used to provide an operating current to the m-th edge pressure region; and A pressed plate, which is used to be adsorbed by the electromagnetic chuck and clamp the target workpiece between the pressed plate and the electromagnetic chuck; The electromagnetic chuck moves with the upper die and acts on the punch, and controls the electromagnetic force in real time to complete the edge pressing of the target workpiece; wherein the electromagnetic force control method includes the following steps: S1, obtain the actual blank holding force of the mth target area at the current time t(n) The working current of the mth edge pressure region at the current time t(n) According to the preset blank holding force curve C of the mth blank holding area m , get the preset blank holding force corresponding to the current time t(n) S2, calculate the error at the current time t(n) Based on e m (n) The working current of the mth pressure edge region at the next moment t(n+1) Perform PID-based PWM control and then control the electromagnetic force; Among them, if Determine the preset blank holder force change dF in the current cycle n , the preset blank holder force change dF in the previous cycle n-1 Whether they have the same trend of change; is the preset blank holding force corresponding to the previous moment t(n-1); is the preset blank holding force corresponding to the next moment t(n+1); If dF n 、dF n-1 have the same trend of change, then Otherwise, keep The direction remains unchanged; In S2, the actual blank holder force derivative of the current cycle is also determined. The actual blank holder force derivative of the previous cycle Whether the absolute value of the difference is greater than the preset minimum change value δ; in, is the actual blank holding force applied to the mth target area at the previous moment t(n-1); is the operating current of the mth edge pressure region at the previous moment t(n-1) like The integral coefficient K in the PID gain parameter d Adjust to eliminate oscillation error; where K d The adjustment method is: K d Adjust the initial value from 0 to 0.1, and then adjust K d Adjust back to the initial value 0; Otherwise, keep the PID gain parameters unchanged.

2. The distributed electromagnetic edge holding device according to claim 1, characterized in that: The mth charging and demagnetization circuit includes a power module U m , solid-state relay KS m , diode Z m , resistor 1 Resistor 2 Intermediate relay KA m ; Among them, U m , KS m , Z m 、 The first circuit is formed; the magnetic pole of the mth edge pressure region, KA m 、 KS m Form the second circuit; KS m Used to control the input or disconnection of the magnetic pole working current in the mth edge pressure area; KA m Used to control the direction of the magnetic pole working current in the mth edge pressure region.

3. The distributed electromagnetic edge holding device according to claim 2, characterized in that: KS m Open, the mth charging and demagnetizing circuit is connected, and the magnetic pole of the mth edge pressure area is energized; KS m Close, the mth charging and demagnetization circuit is disconnected, and no power is supplied to the magnetic pole in the mth edge pressure area.

4. The distributed electromagnetic edge clamping device according to claim 3, in KS m Open case, KA m Switch to one side, and the mth charging and demagnetizing circuit passes a positive working current to the magnetic pole of the mth pressure edge region; KA m Switching to one side, the mth charging and demagnetization circuit passes a reverse working current to the magnetic pole of the mth pressure edge region.

5. The distributed electromagnetic edge holding device according to claim 1, characterized in that: The S1 also includes: Get the distance L between the target workpiece and the punch at the current time t(n) n ; If L n If the distance is less than or equal to the threshold, the magnetic pole of the mth edge pressure region is introduced.

6. The distributed electromagnetic edge holding device according to claim 1, characterized in that: S2 also includes: After the edge pressing of the mth target area is completed, the mth edge pressing area is first demagnetized, and then the mth charging and demagnetization circuit is disconnected.

7. A control system for a distributed electromagnetic edge holding device, characterized in that: It is used to control the distributed electromagnetic edge holding device according to any one of claims 1 to 6; The control system of the distributed electromagnetic edge pressing system includes: The data acquisition module includes a pressure acquisition submodule and a current acquisition submodule; the pressure acquisition submodule is set in M ​​target areas and is used to collect the actual blank holding force of the mth target area at the current time t(n) The current acquisition submodule is set in the M charging and demagnetization circuits to collect the working current of the mth pressure edge area at the current time t(n) m∈[1,M]; as well as The controller is used to obtain the actual blank holding force of the mth target area at the current time t(n) The working current of the mth edge pressure region at the current time t(n) According to the preset blank holding force curve C of the mth blank holding area m , get the preset blank holding force corresponding to the current time t(n) Calculate the error at the current time t(n) Based on e m (n) The working current of the mth pressure edge region at the next moment t(n+1) Perform PID-based PWM control and then control the electromagnetic force; if Determine the preset blank holder force change dF in the current cycle n , the change in blank holding force dF in the previous cycle n-1 Whether they have the same trend of change; is the preset blank holding force corresponding to the previous moment t(n-1); is the preset blank holder force corresponding to the next moment t(n+1); if dF n 、dF n-1 have the same trend of change, then Otherwise, keep The direction remains unchanged.

8. The control system of the distributed electromagnetic edge holding device according to claim 7, characterized in that: The data acquisition module also includes: A distance acquisition submodule is provided on the upper die and is used to measure the distance between the target workpiece and the punch; The controller is also used to obtain the distance L between the target workpiece and the punch at the current time t(n) n ; If L n If the distance is less than or equal to the threshold, the magnetic pole of the mth edge pressure region is introduced.

9. The control system of the distributed electromagnetic edge holding device according to claim 7, characterized in that: The controller is also used to determine the actual blank holder force derivative of the current cycle The actual blank holder force derivative of the previous cycle Whether the absolute value of the difference is greater than the preset minimum change value δ; in, is the actual blank holding force applied to the mth target area at the previous moment t(n-1); is the operating current of the mth edge pressure region at the previous moment t(n-1) like The integral coefficient K in the PID gain parameter d Make adjustments to eliminate oscillation errors; Otherwise, keep the PID gain parameters unchanged.

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