High-precision numerical control bending angle detection device based on laser measurement

Abstract

The application relates to the technical field of laser measurement, in particular to a high-precision numerical control bending angle detection device based on laser measurement, which comprises a strip-shaped base, a concave die seat body, a laser measurement assembly and a control unit; the concave die seat body is fixedly installed on the top of the strip-shaped base; a V-shaped bending groove is arranged on the concave die seat body; rotatable roller pieces are respectively installed on the two sides of the V-shaped bending groove; two groups of the roller pieces are respectively used for rolling contact with the outer surfaces of two vertical surfaces formed after a bending workpiece is bent; the laser measurement assembly is two groups and is arranged on the two sides of the concave die seat body and is used for corresponding measurement of the inclination angles of the two vertical surfaces; whether rebound is completed is accurately judged by detecting whether the roller pieces stop rotating; the rotation of the roller pieces indicates that rebound is still in progress, and the stop of the roller pieces indicates that rebound has ended; measurement triggering changes from prediction to confirmation, and the problem of inaccurate fixed time triggering is fundamentally solved.

Description

Technical Field

[0001] This invention relates to the field of laser measurement technology, and in particular to a high-precision CNC bending angle detection device based on laser measurement. Background Technology

[0002] Bending is an important process for forming metal sheets, widely used in automobile manufacturing, aerospace, rail transportation, and building steel structures. The bending angle is one of the core indicators for measuring bending quality; angular deviation directly affects subsequent assembly accuracy and product performance.

[0003] Currently, laser measurement technology is mainly used for detecting bending angles. A typical laser bending angle detection device includes a linear laser module and an industrial camera set on both sides of the bending machine. The laser module projects a linear laser beam obliquely onto the two bending faces of the workpiece, and the industrial camera receives the reflected laser lines on the corresponding faces. The spatial coordinates and tilt angle of the faces are calculated by converting the pixel positions of the laser lines in the camera image, and then the actual included angle of the V-bend is obtained through spatial geometric calculations.

[0004] In existing bending processes, metal sheets undergo plastic deformation after the punch presses into the die. However, when the punch is lifted and the external force is unloaded, the sheet elastically recovers. Springback is one of the main factors affecting the accuracy of bending angles. Existing laser angle detection systems typically complete the measurement at the instant the workpiece fully springs back after the slider is lifted, to obtain the true angle of the finished product rather than the temporary angle during pressing. However, in actual production, the springback speed varies depending on factors such as material, thickness, and die condition. High-strength steel springs back quickly, ordinary steel springs back slowly, and aluminum falls in between. Using a fixed-delay trigger camera exposure method makes it difficult to accurately match the springback completion time of workpieces of different materials, affecting the accuracy of bending angle measurement. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-precision CNC bending angle detection device based on laser measurement.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a high-precision CNC bending angle detection device based on laser measurement, comprising a strip base, a die holder, a laser measurement component, and a control unit;

[0007] The die base is fixedly installed on the top of the strip base. The die base is provided with a V-shaped bending groove. Rotatable rollers are installed on the two shoulders of the V-shaped bending groove. The two sets of rollers are respectively used to roll into contact with the outer surfaces of the two vertical surfaces formed after the workpiece is bent.

[0008] The laser measurement components are in two sets, respectively located on both sides of the concave mold base, for measuring the tilt angles of the two vertical surfaces.

[0009] Each of the rollers is equipped with a rotation state detector, which is used to detect the rotation state of the corresponding roller and output a rotation signal;

[0010] The control unit is connected to each of the rotation state detectors and each of the laser measurement components, and is also connected to the CNC system of the bending machine to receive the return information of the punch.

[0011] The control unit is configured to: upon receiving the return information, when the rotation signal on one side indicates that the side roller stops rotating, output a trigger signal to the laser measurement component on the corresponding side, causing the laser measurement component on that side to collect laser measurement data of the corresponding facade; when the rotation signal on the other side indicates that the side roller stops rotating, output a trigger signal to the laser measurement component on the corresponding side, causing the laser measurement component on that side to collect laser measurement data of the corresponding facade.

[0012] Preferably, the device further includes a brake disposed on the rotating shaft of each of the rollers, the brake being signal-connected to the control unit; the control unit is further configured to: when each of the rollers on each side stops rotating and outputs a trigger signal, control the brake on the corresponding side to activate and lock that roller.

[0013] Preferably, the brake is an electromagnetic power-off brake, which includes a stator and a rotor. The stator of the electromagnetic power-off brake is fixedly installed on the die holder, and the rotor of the electromagnetic power-off brake is connected to the rotating shaft of the roller. When the electromagnetic power-off brake is energized, it releases the roller, and when the power is off, it brakes the roller.

[0014] Preferably, the rotation state detector includes a magnet fixedly disposed on the surface of the roller shaft and a Hall sensor group fixedly disposed on the die holder, wherein the sensing surface of the Hall sensor group is facing the rotation trajectory of the magnet.

[0015] Preferably, there are multiple magnets, which are spaced apart along the circumferential direction of the roller shaft, and each magnet is offset from the axis of the roller shaft.

[0016] Preferably, when the rotation signal indicates that the roller has stopped rotating, a delay timer is started first. If the roller is still in a stopped state after the delay ends, the trigger signal is then output.

[0017] Preferably, the control unit is further configured to: record the first time when one side of the roller stops rotating and the second time when the other side of the roller stops rotating, calculate the time difference between the first time and the second time, and output an alarm signal when the time difference exceeds a preset threshold.

[0018] Preferably, the Hall sensor group includes a first Hall sensor and a second Hall sensor respectively disposed at the ends of the corresponding roller shaft, and the first Hall sensor and the second Hall sensor have a preset phase difference; the control unit determines the rotation direction of the side roller according to the order of the output pulses of the first Hall sensor and the second Hall sensor.

[0019] Preferably, the control unit is further configured to: when it is determined that the side roller rotates in the opposite direction during the rebound process, control the brake on the corresponding side to perform temporary braking; the temporary braking is: controlling the brake to brake and holding for a preset time before releasing.

[0020] Preferably, the preset time is 50-200ms.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. By detecting whether the rollers have stopped rotating, the completion of springback can be accurately determined. Roller rotation indicates that springback is still in progress, while roller stopping indicates that springback has ended. The measurement triggering method has changed from predictive to confirmatory, fundamentally solving the problem of inaccuracy in fixed-delay triggering.

[0023] 2. The rollers on both sides are independently detected and their respective laser measurement components are independently triggered. Even if the two sides rebound asynchronously, the cameras on both sides can complete the shooting at the moment when the rebound on their respective sides is truly completed, completely eliminating the angle measurement error caused by the asynchronous rebound on both sides.

[0024] 3. By determining the rotation direction of the rollers through the first Hall sensor and the second Hall sensor, abnormal shaking can be detected during the rebound process and temporary braking can be performed in time, effectively suppressing unstable vibrations during the rebound process and making the rebound process quickly stabilize. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the first structure of the die holder of the present invention;

[0027] Figure 3 For the present invention Figure 2 Enlarged schematic diagram of the structure at point A in the diagram;

[0028] Figure 4 This is a schematic diagram of the second structure of the die holder of the present invention;

[0029] Figure 5 For the present invention Figure 4 Enlarged schematic diagram of the structure at point B in the diagram;

[0030] Figure 6 This is a schematic diagram of the laser measurement component structure of the present invention.

[0031] In the diagram: 100, strip base; 200, die holder; 210, V-shaped bending groove; 211, mounting groove; 220, roller; 221, rotating shaft; 230, magnet; 240, Hall sensor group; 241, first Hall sensor; 242, second Hall sensor; 300, laser measurement assembly; 310, linear laser module; 320, industrial camera; 400, electromagnetic power-off brake; 410, stator section; 420, rotor section. Detailed Implementation

[0032] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0033] like Figures 1 to 6 The high-precision CNC bending angle detection device based on laser measurement shown includes a strip base 100, a die holder 200, a laser measurement component 300, and a control unit.

[0034] The strip base 100 is a long strip structure that extends along the length of the bending machine and is fixedly installed on the worktable of the bending machine. The die holder 200 is fixedly installed on the top of the strip base 100, and a V-shaped bending groove 210 is provided on the die holder 200. The V-shaped bending groove 210 extends along the length of the die holder 200, and its cross-section is V-shaped. The die holder 200 is made of tool steel and has high hardness and wear resistance after quenching treatment.

[0035] The V-shaped bending groove 210 has mounting grooves 211 on both sides of its shoulder, and two sets of rollers 220 are rotatably mounted in the mounting grooves 211 on both sides. The two sets of rollers 220 are symmetrically arranged on both sides of the V-shaped bending groove 210, and the axial direction of the rollers 220 is parallel to the length direction of the V-shaped bending groove 210.

[0036] Two sets of laser measuring components 300 are respectively set on both sides of the die holder 200 to measure the tilt angle of the two vertical surfaces formed after the workpiece is bent.

[0037] The control unit is located in the electrical control cabinet of the bending machine and is connected to the rotation status detectors and two sets of laser measurement components 300 installed on each roller 220.

[0038] Each roller 220 is rotatably mounted in the mounting groove 211 of the die holder 200 via a rotating shaft 221. The roller 220 has a cylindrical structure with a smooth cylindrical surface on its outer surface, which is used for rolling contact with the vertical outer surface of the bent workpiece.

[0039] Each roller 220 is equipped with a rotation status detector, which is used to detect the rotation status of the corresponding roller 220 and output a rotation signal.

[0040] In this embodiment, the rotation state detector adopts a structure in which the magnet 230 and the Hall sensor group 240 are combined.

[0041] Magnet 230 is a permanent magnet, fixedly mounted on the surface of the rotating shaft 221 of the roller 220. Multiple magnets 230 are evenly spaced along the circumference of the rotating shaft 221 to increase the number of pulses per unit rotation angle and ensure the detection resolution for minute rotations of the roller 220. Specifically, multiple blind holes are spaced off-center from the axis of the rotating shaft 221, and magnets 230 are fixedly installed in each blind hole by tight fit and adhesive. Magnets 230 rotate synchronously with the rotating shaft 221. When the rotating shaft 221 rotates, magnets 230 move in a circular motion around the axis of the rotating shaft 221, periodically approaching and moving away from the fixedly mounted Hall sensor group 240.

[0042] The Hall sensor assembly 240 is fixedly mounted on the die holder 200, with its sensing surface facing the rotation trajectory of the magnet 230. The signal output terminal of the Hall sensor assembly 240 is connected to the control unit via a shielded cable.

[0043] When roller 220 rotates, shaft 221 drives magnet 230 to rotate synchronously. Magnet 230 periodically moves closer to and further away from Hall sensor group 240, causing the magnetic field strength sensed by Hall sensor group 240 to change periodically. Hall sensor group 240 converts the periodic changes in magnetic field strength into electrical pulse signals for output. When roller 220 stops rotating, magnet 230 stops moving, the magnetic field strength sensed by Hall sensor group 240 remains constant, and the output electrical signal remains constant.

[0044] Therefore, the control unit can determine whether the roller 220 is rotating by detecting whether there is a pulse signal output by the Hall sensor group 240. A pulse signal indicates that the roller 220 is rotating, and no pulse signal indicates that the roller 220 has stopped rotating.

[0045] In a preferred embodiment, the Hall sensor group 240 includes a first Hall sensor 241 and a second Hall sensor 242, with the two Hall sensors respectively disposed at the ends of the rotating shaft 221 of the corresponding roller 220. The first Hall sensor 241 and the second Hall sensor 242 have a preset phase difference (e.g., 120° electrical angle).

[0046] When the magnet 230 rotates with the shaft 221, the first Hall sensor 241 and the second Hall sensor 242 output pulse signals sequentially. The control unit determines the rotation direction of the side roller 220 based on the order of the pulses output by the first Hall sensor 241 and the second Hall sensor 242.

[0047] If the first Hall sensor 241 outputs a pulse first and the second Hall sensor 242 outputs a pulse later, then it is determined to be the forward rotation direction;

[0048] If the second Hall sensor 242 outputs a pulse first and the first Hall sensor 241 outputs a pulse later, it is determined that the direction is reversed.

[0049] During the bending process, the rotation direction of the roller 220 reflects the movement direction of the workpiece's vertical surface: during bending, the roller 220 rotates in one direction, and during springback, the roller 220 rotates in the opposite direction. By determining the rotation direction, the control unit can distinguish whether the rotation of the roller 220 comes from the bending process or the springback process, and whether abnormal reverse wobbling has occurred.

[0050] Two sets of laser measurement components 300 are respectively disposed on both sides of the concave mold base 200. For example... Figure 6 As shown, each laser measurement assembly 300 includes a line laser module 310 and an industrial camera 320. The line laser module 310 and the industrial camera 320 are respectively connected to a control unit. The control unit controls the opening and closing of the line laser module 310 and receives image data acquired by the industrial camera 320.

[0051] During the bending process, the linear laser module 310 continuously projects a linear laser line onto the vertical surface of the corresponding bent workpiece, forming a bright projection line on the surface. The industrial camera 320 is in a ready-to-trigger state—continuously acquiring preview images but not storing them. When the control unit determines that the springback on that side is complete, it outputs a trigger signal to the industrial camera 320, which immediately completes the exposure and acquisition of a single frame image, obtaining the laser line image data at that moment.

[0052] The control unit processes the acquired laser line image: extracting the pixel coordinates of the laser line in the image, and converting the pixel coordinates into the spatial coordinates and tilt angle of the bent workpiece's facade using laser triangulation based on pre-calibrated optical parameters. After calculating the tilt angles of both facades, the control unit obtains the actual included angle of the V-bend through spatial geometric calculations.

[0053] In a preferred embodiment, each roller 220 is further provided with a brake on its shaft 221, and the brake is signal-connected to the control unit. The brake is an electromagnetic de-energization brake 400. The electromagnetic de-energization brake 400 includes a stator portion 410 and a rotor portion 420.

[0054] The stator section 410 includes a magnetic yoke, an excitation coil, and a braking spring, and is fixedly mounted on the die holder 200. The rotor section 420 includes a brake disc and a spline sleeve, and is connected to the rotating shaft 221 of the roller 220 via the spline sleeve, rotating synchronously with the rotating shaft 221.

[0055] The control terminal of the electromagnetic power-off brake 400 is connected to the control unit via a signal connection. The control unit controls the on / off state of the electromagnetic power-off brake 400.

[0056] When the control unit outputs DC voltage to the electromagnetic power-off brake 400, the excitation coil is energized to generate electromagnetic force, which overcomes the elastic force of the brake spring and attracts the armature, causing the armature to separate from the brake disc. The electromagnetic power-off brake 400 is in the released state, and the roller 220 can rotate freely.

[0057] When the control unit disconnects the power supply to the electromagnetic de-energizer 400, the excitation coil is de-energized, and the electromagnetic force disappears. The brake spring pushes the armature to press the brake disc against the magnetic yoke, generating a frictional torque. The electromagnetic de-energizer 400 is in the braking state, and the roller 220 is locked.

[0058] The control unit includes a microcontroller, a signal input interface, a trigger output interface, a brake drive interface, a power management module, and a storage module.

[0059] The signal input interface is connected to the signal output terminal of the Hall sensor group 240 set on each roller 220, and is used to receive the pulse signal or static signal output by the Hall sensor group 240.

[0060] The trigger output interface is connected to the trigger input terminal of the industrial camera 320 of the two sets of laser measurement components 300 respectively, and is used to output trigger signals to control the exposure of the industrial camera 320.

[0061] The brake drive interface is connected to the control terminal of the electromagnetic power-off brake 400 installed on each roller 220, and is used to control the on and off state of the electromagnetic power-off brake 400.

[0062] The microcontroller has a pre-installed control program configured to execute the following control logic:

[0063] The microcontroller receives the punch return signal output by the CNC system of the bending machine. Only after receiving the return signal will it perform stop judgment and trigger logic on the signals of each Hall sensor group 240 to avoid false triggering caused by the roller 220 being stationary during the punch holding pressure stage.

[0064] The microcontroller monitors the signals input by each Hall sensor group 240 in real time. When the Hall sensor group 240 outputs a continuous pulse signal, the microcontroller determines that the corresponding roller 220 is rotating; when the signal output by the Hall sensor group 240 remains constant (without pulse change) for a preset time (e.g., 10ms), the microcontroller determines that the corresponding roller 220 has stopped rotating.

[0065] When the microcontroller determines that one of the rollers 220 has stopped rotating, it outputs a trigger signal to the corresponding industrial camera 320 on that side, causing the industrial camera 320 on that side to complete the exposure acquisition. Specifically:

[0066] When one side roller 220 stops rotating, the microcontroller outputs a trigger signal to the industrial camera 320 on that side, and the industrial camera 320 on that side collects laser measurement data of the corresponding facade.

[0067] When the other roller 220 stops rotating, the microcontroller outputs a trigger signal to the other industrial camera 320, and the other industrial camera 320 collects laser measurement data of the corresponding facade.

[0068] The triggering on both sides is independent of each other—the stopping of one side roller 220 only triggers the camera on that side, and the stopping of the other side roller 220 only triggers the camera on the other side, without affecting each other.

[0069] To avoid misjudgments caused by vibration or electromagnetic interference, the microcontroller does not immediately output a trigger signal after detecting a stop signal from roller 220. Instead, it starts a delay timer (the delay time is preset to 5-20ms and can be adjusted according to actual working conditions). After the delay, the microcontroller checks the rotation status signal of roller 220 again: if roller 220 is still stopped, it confirms that the rebound has been completed and outputs a trigger signal; if roller 220 starts rotating again during the delay period (indicating the presence of minor oscillations), the timer is reset and monitoring resumes.

[0070] The microcontroller records the first time when one side of the roller 220 stops rotating and the second time when the other side of the roller 220 stops rotating, and calculates the time difference between the two. When the time difference exceeds a preset threshold (e.g., 50ms), the microcontroller outputs an alarm signal through the bending machine's operating interface or alarm device, prompting the operator to check whether the bending machine is under uneven load or whether the hydraulic system is malfunctioning.

[0071] In the embodiment employing a first Hall sensor 241 and a second Hall sensor 242, the microcontroller determines the rotation direction of the side roller 220 based on the order of the output pulses from the first Hall sensor 241 and the second Hall sensor 242.

[0072] When the microcontroller determines that the roller 220 on the corresponding side rotates in the opposite direction during the springback process (that is, the rotation direction of the roller 220 is opposite to the springback direction, indicating that the workpiece has abnormal shaking during the springback process), the microcontroller controls the electromagnetic de-energizer 400 on the corresponding side to perform temporary braking.

[0073] The temporary braking is as follows: the microcontroller disconnects the power supply to the electromagnetic power-off brake 400, the electromagnetic power-off brake 400 brakes and maintains the braking for a preset time (e.g., 50-200ms) to suppress the shaking; after the preset time ends, the microcontroller restores the power supply to the electromagnetic power-off brake 400, the electromagnetic power-off brake 400 is released, the roller 220 resumes free rotation, and the rebound process continues.

[0074] If reverse rotation is detected again after temporary braking, the microcontroller can repeat the temporary braking until the rebound process stabilizes or exceeds the preset number of attempts, at which point an alarm will be triggered.

[0075] When each side roller 220 stops rotating and outputs a trigger signal, the microcontroller controls the corresponding side's electromagnetic power-off brake 400 to activate and lock that side roller 220. Specifically, the microcontroller disconnects the power supply to the electromagnetic power-off brake 400, the electromagnetic power-off brake 400 brakes, and the roller 220 is locked, preventing the roller 220 from rotating again due to vibration or external interference after the measurement is completed.

[0076] Working principle of this invention:

[0077] The workpiece to be bent is placed on the die holder 200, spanning the V-shaped bending groove 210, with its two sides resting on the rollers 220 on either side of the V-shaped bending groove 210. The bending machine is started, and the punch descends, pressing into the V-shaped bending groove 210. Under the pressure of the punch, the workpiece gradually bends, and its two sides gradually rotate into the V-shaped bending groove 210. During this process, the outer surfaces of the two sides roll into contact with the corresponding rollers 220, and the rollers 220 rotate in opposite directions as the sides rotate.

[0078] Simultaneously, two sets of linear laser modules 310 continuously project linear laser lines onto the corresponding facades, while the industrial camera 320 remains in a ready-to-trigger state (continuously acquiring preview images but not storing them). Hall sensor groups 240 on each roller 220 continuously output pulse signals, and the control unit monitors the status of each pulse signal in real time.

[0079] After the punch reaches the bottom dead center, it holds pressure for a certain period of time, and then the punch is lifted. After the workpiece loses external force, it elastically recovers, and the two side faces rotate outwards, causing the two side rollers 220 to roll in the opposite direction. During this process, the control unit keeps all electromagnetic de-energizers 400 energized (in the released state) and does not interfere with the free rotation of the rollers 220. Each Hall sensor group 240 continues to output pulse signals, and the pulse frequency gradually decreases as the rebound speed decreases. The control unit continuously monitors each pulse signal.

[0080] When one side of the facade completes its rebound and stops rotating, the roller 220 on that side also stops rotating. The pulse signal output by the Hall sensor group 240 on that roller 220 disappears (becomes a constant signal).

[0081] After the control unit detects the disappearance of the pulse signal from the Hall sensor group 240 on that side, it starts a delay timer (delay 5-20ms). After the delay ends, the control unit checks the signal from the Hall sensor group 240 on that side again: if it is still a constant signal (no pulse), it confirms that the rebound on that side has been completed.

[0082] The control unit then outputs a trigger signal to the industrial camera 320 on that side, and the industrial camera 320 immediately completes the exposure acquisition to obtain the laser line image at that moment.

[0083] The same judgment and triggering process is executed independently on the other side—when one side roller 220 stops rotating, it triggers the camera on that side; when the other side roller 220 stops rotating, it triggers the camera on the other side. The two sides do not affect each other.

[0084] After the industrial cameras 320 on both sides complete their exposures, they transmit the captured laser line images to the control unit. The control unit processes the images from both sides separately: extracts the pixel coordinates of the laser lines, calculates the spatial coordinates and tilt angles of the two facades based on the calibrated optical parameters, and then obtains the actual included angle of the V-shaped bend through spatial geometric calculations.

[0085] The control unit compares the calculated bending angle with the target angle and feeds back the deviation value to the CNC system of the bending machine for automatic compensation in subsequent bending.

[0086] After the measurement is completed, the control unit disconnects the power supply to each electromagnetic power-off brake 400. The electromagnetic power-off brake 400 activates to lock each roller 220, preventing the roller 220 from rotating due to external interference before the next bend.

[0087] The control unit records the time when the rollers 220 on both sides stop rotating during each bend and calculates the time difference between the two sides. When the time difference exceeds a preset threshold, the control unit outputs an alarm signal through the bending machine's operating interface, prompting the operator to check whether the bending machine is under uneven load or whether the hydraulic system is malfunctioning.

[0088] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A high-precision CNC bending angle detection device based on laser measurement, comprising a strip base 100, a die holder 200, a laser measurement component 300, and a control unit; characterized in that: The die holder 200 is fixedly installed on the top of the strip base 100. The die holder 200 is provided with a V-shaped bending groove 210. Rotatable rollers 220 are respectively installed on the two shoulders of the V-shaped bending groove 210. The two sets of rollers 220 are respectively used to roll contact with the outer surfaces of the two vertical surfaces formed after the workpiece is bent. The laser measurement components 300 are in two sets, respectively disposed on both sides of the concave mold base 200, for measuring the tilt angle of the two facades. Each of the rollers 220 is provided with a rotation state detector, which is used to detect the rotation state of the corresponding roller 220 and output a rotation signal; The control unit is connected to each of the rotation state detectors and each of the laser measurement components 300, and is also connected to the CNC system of the bending machine to receive the return information of the punch. The control unit is configured to: upon receiving the return information, when the rotation signal on one side indicates that the side roller 220 stops rotating, output a trigger signal to the laser measurement component 300 on the corresponding side, causing the laser measurement component 300 on that side to collect laser measurement data of the corresponding facade; when the rotation signal on the other side indicates that the side roller 220 stops rotating, output a trigger signal to the laser measurement component 300 on the corresponding side, causing the laser measurement component 300 on that side to collect laser measurement data of the corresponding facade.

2. The high-precision CNC bending angle detection device based on laser measurement according to claim 1, characterized in that: It also includes a brake disposed on the rotating shaft 221 of each of the rollers 220, the brake being signal-connected to the control unit; the control unit is further configured to: when each of the rollers 220 on each side stops rotating and outputs a trigger signal, control the brake on the corresponding side to act to lock the roller 220 on that side.

3. The high-precision CNC bending angle detection device based on laser measurement according to claim 2, characterized in that: The brake is an electromagnetic power-off brake 400, which includes a stator portion 410 and a rotor portion 420. The stator portion 410 of the electromagnetic power-off brake 400 is fixedly installed on the die holder 200, and the rotor portion 420 of the electromagnetic power-off brake 400 is connected to the rotating shaft 221 of the roller 220. When the electromagnetic power-off brake 400 is energized, it releases the roller 220, and when the power is off, it brakes the roller 220.

4. The high-precision CNC bending angle detection device based on laser measurement according to claim 2 or 3, characterized in that: The rotation state detector includes a magnet 230 fixedly mounted on the surface of the roller 220 shaft 221 and a Hall sensor group 240 fixedly mounted on the die holder 200, with the sensing surface of the Hall sensor group 240 facing the rotation trajectory of the magnet 230.

5. The high-precision CNC bending angle detection device based on laser measurement according to claim 4, characterized in that: There are multiple magnets 230, which are spaced apart along the circumferential direction of the rotating shaft 221 of the roller 220, and each magnet 230 is offset from the axis of the rotating shaft 221 of the roller 220.

6. The high-precision CNC bending angle detection device based on laser measurement according to any one of claims 1-3, characterized in that: When the rotation signal indicates that the roller 220 has stopped rotating, a delay timer is started first. If the roller 220 is still in a stopped state after the delay ends, the trigger signal is then output.

7. The high-precision CNC bending angle detection device based on laser measurement according to any one of claims 1-3, characterized in that: The control unit is also configured to: record the first time when one side of the roller 220 stops rotating and the second time when the other side of the roller 220 stops rotating, calculate the time difference between the first time and the second time, and output an alarm signal when the time difference exceeds a preset threshold.

8. The high-precision CNC bending angle detection device based on laser measurement according to claim 4, characterized in that: The Hall sensor group 240 includes a first Hall sensor 241 and a second Hall sensor 242 respectively disposed at the ends of the rotating shaft 221 of the corresponding roller 220. The first Hall sensor 241 and the second Hall sensor 242 have a preset phase difference. The control unit determines the rotation direction of the side roller 220 according to the order of the pulses output by the first Hall sensor 241 and the second Hall sensor 242.

9. The high-precision CNC bending angle detection device based on laser measurement according to claim 8, characterized in that: The control unit is also configured to: when it is determined that the side roller 220 rotates in the opposite direction during the rebound process, control the brake on the corresponding side to perform temporary braking; the temporary braking is: controlling the brake to brake and holding for a preset time before releasing.

10. The high-precision CNC bending angle detection device based on laser measurement according to claim 9, characterized in that: The preset time is 50-200ms.

Images