Pose recognition method, compensation correction control method and system for hydraulic machine movable beam

Abstract

The invention relates to the technical field of hydraulic forming, and discloses a pose recognition method and a compensation correction control method and system for a hydraulic machine movable beam. The method is applied to a hydraulic machine pose recognition compensation system which comprises a movable beam, a main cylinder and four hydraulic compensation cylinders. According to the method, after a movable beam begins to descend, the pressure sudden change time difference of the diagonal hydraulic compensation cylinders is calculated; taking the first contact in the opposite angles as a reference cylinder, collecting the piston rod displacement of the main cylinder and the reference cylinder in the corresponding time difference, calculating the inclination angle of the movable beam in the diagonal direction, and identifying the position and posture state of the movable beam, so as to calculate the position compensation amount for safety judgment, and if the maximum inclination value is within a preset threshold value, judging the safety of the movable beam. If so, calculating control parameters of the next forming period according to the position compensation amount, and performing compensation correction control on the movable beam. According to the method, the inclination condition of the movable beam can be rapidly recognized, the non-synchronous pose of the movable beam is corrected, impact oscillation caused by initial inclination of the movable beam is reduced, and the precision of the subsequent leveling stage is improved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic forming technology, specifically to a method for recognizing the position of a moving beam in a hydraulic press, a method for compensating and correcting control, and a system thereof. Background Technology

[0002] In the hydroforming process, the movable beam, as a key component that supports the upper mold and transmits load to the workpiece, directly affects the forming quality of the workpiece and the service life of the mold and the entire machine. When the movable beam cannot maintain an ideal parallel posture during its descent, significant differences in force will occur at the four corners, resulting in large impact loads during docking and inducing damage to the guide rails, cylinder, and mold. Therefore, accurately identifying the position of the movable beam before the hydroforming stage and implementing timely and reasonable adjustments and compensation controls based on this information is of great significance for ensuring the safe operation of the equipment and guaranteeing product quality.

[0003] Currently, hydraulic presses often rely on manual measurement and experience to correct the posture of the moving beam when it initially tilts. This typically involves measuring the four corners and connection points of the moving beam using a level while the machine is stopped, and then adjusting shims, connecting rods, or fasteners to achieve the beam's position. This method is not only dependent on operator experience, but also suffers from inconsistent repeatability and accuracy, and has a long debugging cycle, slowing down production. While some equipment is equipped with a four-corner leveling posture recognition and compensation system, these systems are mostly for simple synchronization based on the displacement or pressure of the leveling cylinders during the pressing and forming stage, lacking a unified description and online recognition method for the overall posture of the moving beam. Therefore, this research aims to study the use of cylinder data obtained during the docking stage for safe judgment and compensation control of the moving beam's posture. This approach enables real-time monitoring and safe judgment of the moving beam's posture without interrupting production, improving the automation and safety of the hydraulic posture recognition and compensation system. Summary of the Invention

[0004] To address the technical problems existing in the prior art, this invention provides a method for recognizing the position of a moving beam in a hydraulic press, a method for compensating and correcting it, and a system. The aim is to quickly identify the tilt of the moving beam and correct its asynchronous docking position, thereby reducing the impact and vibration caused by the initial tilt of the moving beam and improving the accuracy of the subsequent leveling stage.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention discloses a pose recognition method for a moving beam of a hydraulic press, applied to a pose recognition and compensation system for a hydraulic press. The system includes a moving beam, a main cylinder mounted at the center of the upper surface of the moving beam for driving its descent, and four hydraulic compensation cylinders for supporting the moving beam and adjusting its pose during descent. The four hydraulic compensation cylinders are distributed below the four corners of the moving beam and are symmetrically distributed relative to the center of the moving beam, and are separated from the moving beam before descent. The pose recognition method includes the following steps: S1: After the movable beam begins to descend, the pressure in the lower chamber of the hydraulic compensation cylinder is collected in real time. The pressure change time of the lower chamber when the movable beam contacts the four hydraulic compensation cylinders is recorded respectively, and the pressure change time difference of the diagonal hydraulic compensation cylinders is calculated. S2: Using the diagonal hydraulic compensation cylinder that first contacts the moving beam as the reference cylinder, the piston rod displacement of the main cylinder and the reference cylinder during the corresponding pressure change time difference is collected respectively, and the tilt angle of the moving beam along the diagonal direction is calculated accordingly. S3: Based on the tilt angle of the movable beam along the diagonal direction, calculate the tilt angle of the movable beam along the x-axis and y-axis of the horizontal coordinate system, thus identifying the pose state of the movable beam.

[0006] As a further improvement to the above scheme, in step S1, the formula for calculating the time difference of pressure change in the diagonal hydraulic compensation cylinder is as follows:

[0007] In the formula, , , and The times of pressure change in the lower chamber of hydraulic compensation cylinders 1, 2, 3, and 4 are shown in sequence. The time difference of pressure change between diagonal hydraulic compensation cylinders 1 and 3. The time difference of pressure change between diagonal hydraulic compensation cylinders 2 and 4; In step S2, the diagonal hydraulic compensation cylinder that first contacts the moving beam, either cylinder 1 or cylinder 3, is used as the reference cylinder. Internally collected reference cylinder piston rod displacement and the displacement of the master cylinder piston rod A relative displacement coordinate system of the movable beam with respect to the piston rod of the reference cylinder is established to obtain the displacement difference between the master cylinder and the reference cylinder. Approximating it as the chord length, the inclination angle of the movable beam in radians along the diagonal directions of hydraulic compensation cylinders 1 and 3 is: ;in Let the length of the movable beam be the length of its diagonal. , width is ,but ; Using the diagonal hydraulic compensation cylinders No. 2 and No. 4 that first contact the moving beam as the reference cylinder, in Internally collected reference cylinder piston rod displacement and the displacement of the master cylinder piston rod A relative displacement coordinate system of the movable beam with respect to the piston rod of the reference cylinder is established to obtain the displacement difference between the master cylinder and the reference cylinder. Approximating it as the chord length, the inclination angle of the movable beam in radians along the diagonal directions of hydraulic compensation cylinders No. 2 and No. 4 is: .

[0008] As a further improvement to the above scheme, in step S3, the formula for calculating the inclination angle of the movable beam in radians along the x-axis and y-axis of the horizontal coordinate system is as follows:

[0009] In the formula, Let x be the angle of inclination of the movable beam along the x-axis; Let be the angle of inclination of the movable beam along the y-axis.

[0010] As a further improvement to the above scheme, in step S3, the position compensation values ​​of the four hydraulic compensation cylinders are also calculated using the following formula:

[0011] In the formula, the cylinder that first comes into contact with the moving beam among the four hydraulic compensation cylinders is defined as the first contact cylinder. The compensation value is for the position of the cylinder that first comes into contact with the cylinder. The position compensation value of the hydraulic compensation cylinder along the x-axis direction of the cylinder that first contacts the cylinder; The position compensation value of the hydraulic compensation cylinder along the y-axis direction of the cylinder that first contacts the cylinder; This is the position compensation value for the hydraulic compensation cylinder located diagonally opposite the first contact cylinder.

[0012] This invention also discloses a compensation and correction control method for a moving beam of a hydraulic press, applied to a posture recognition and compensation system of a hydraulic press. The system includes a moving beam, a main cylinder mounted at the center of the upper surface of the moving beam for driving its descent, and four hydraulic compensation cylinders for supporting the moving beam and adjusting its posture during descent. The four hydraulic compensation cylinders are distributed below the four corners of the moving beam and are symmetrically distributed relative to the center of the moving beam, and are separated from the moving beam before descent. The compensation and correction control method includes the following steps: Step 1: Before the hydraulic press begins forming, initialize the pose recognition and compensation system and initialize the forming cycle counter to... The speed feedback control amount of the four hydraulic compensation cylinders in the pre-adjustment stage will be adjusted. Feedforward compensation voltage Initialize to 0, and extend the piston rod of the hydraulic compensation cylinder to the extended position. Initialize to the initial extension position of the system during the return phase. ;in ; Step Two: The hydraulic press starts working, controlling the piston rod of the hydraulic compensation cylinder according to... Extend to the designated docking position, so that Entering the forming stage; Step 3: During the forming process, the above-mentioned pose recognition method is used to identify the pose state of the moving beam and calculate the position compensation amount of each hydraulic compensation cylinder. ; Step 4: Adjust the compensation amount for the four positions. The maximum value in the range is the maximum tilt value of the movable beam. With the preset maximum tilt threshold If a comparison is made, Then, based on the location compensation amount Calculate the control parameters for the next forming cycle, including: piston rod extension position. Speed ​​feedback control quantity during the pre-adjustment stage and feedforward compensation voltage ; Step 5: Enter the pre-adjustment stage, using the speed feedback control amount obtained from the previous forming cycle. and feedforward compensation voltage Compensation control is performed to adjust the piston rod speed of the four hydraulic compensation cylinders so that the movable beam returns to a horizontal position before the leveling stage. Step Six: Enter the leveling stage. After completing this forming process, return to Step Two.

[0013] As a further improvement to the above scheme, in step four, if If the alarm is triggered, the machine will automatically stop and output the position and orientation status of the moving beam.

[0014] The present invention also discloses a posture recognition and compensation system for a hydraulic press, including a movable beam, a main cylinder mounted on the center of the upper surface of the movable beam for driving the movable beam to descend, and four hydraulic compensation cylinders for supporting the movable beam and adjusting its posture during the descent. The four hydraulic compensation cylinders are distributed below the four corners of the movable beam and are symmetrically distributed with respect to the center of the movable beam. They are separated from the movable beam before descent. The posture recognition and compensation system also includes a controller, which is used to execute the compensation and correction control method described above to realize the compensation and correction control of the movable beam.

[0015] As a further improvement to the above solution, the pose recognition and compensation system also includes a monitoring unit; the monitoring unit includes displacement sensors installed on the main cylinder and four hydraulic compensation cylinders, used to collect the displacement of the piston rod of the corresponding cylinder.

[0016] As a further improvement to the above solution, the monitoring unit also includes pressure sensors installed on four hydraulic compensation cylinders for collecting hydraulic oil pressure in the lower chamber of the cylinder.

[0017] As a further improvement to the above solution, the pose recognition and compensation system also includes a servo valve and an oil source; the servo valve is used to control the flow and direction of hydraulic oil in the hydraulic compensation cylinder, and the oil source is used to supply oil to the hydraulic press.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. The method for recognizing the position of a moving beam in a hydraulic press disclosed in this invention quickly identifies the position state of the moving beam by analyzing the position and pressure signals obtained from sensors. Since the movement trajectory of the moving beam is not strictly along the Z-axis, but has offsets along the x and y axes, the measurement error of the displacement sensor can easily mask these minor deviations. However, pressure changes are more significant. By using the different rise times of the pressure signals to determine the contact time between each hydraulic compensation cylinder and the moving beam, the tilt state of the moving beam can be identified more accurately.

[0019] 2. The compensation and correction control method for the moving beam of the hydraulic press disclosed in this invention, by compensating and controlling the return position of the compensation cylinder and adding a pre-leveling stage before entering the leveling stage to compensate and control the position of the compensation cylinder, can make four compensation cylinders contact the moving beam simultaneously during docking, and make the moving beam in a horizontal state when entering the leveling stage, thereby reducing the impact and vibration of the moving beam caused by the initial tilt and improving the accuracy of the subsequent leveling stage.

[0020] 3. The hydraulic press posture recognition and compensation system disclosed in this invention can achieve the same beneficial effects as the above method by applying the above method, and will not be described in detail here. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the pose recognition and compensation system of the hydraulic press in Embodiment 1 of the present invention.

[0022] Figure 2 This is a flowchart of the pose recognition method for the moving beam of the hydraulic press in Embodiment 2 of the present invention.

[0023] Figure 3 This is a timing diagram of the pressure change signal detected by the pressure sensor in Embodiment 2 of the present invention.

[0024] Figure 4This is a schematic diagram of the displacement from the connection stage to the leveling stage of the movable beam in Embodiment 2 of the present invention.

[0025] Figure 5 This is a schematic diagram of the pose state of the movable beam when it is tilted and the corresponding position compensation value in Embodiment 2 of the present invention.

[0026] Figure 6 This is a schematic diagram showing the positions of the movable beam and the hydraulic compensation cylinder at each stage before compensation control in Embodiment 2 of the present invention.

[0027] Figure 7 This is a schematic diagram showing the positions of the movable beam and the hydraulic compensation cylinder at each stage after compensation control in Embodiment 2 of the present invention.

[0028] Figure 8 This is a control flowchart of the compensation and correction control method for the moving beam of the hydraulic press in Embodiment 2 of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] This embodiment provides a posture recognition and compensation system for a hydraulic press, including a movable beam 2, a main cylinder 1 installed at the center of the upper surface of the movable beam 2 for driving the movable beam 2 to descend, and four hydraulic compensation cylinders (i.e., 3a~3d) for supporting the movable beam 2 and adjusting its posture during the descent. The four hydraulic compensation cylinders are distributed below the four corners of the movable beam 2 and are symmetrically distributed with respect to the center of the movable beam 2. They are separated from the movable beam 2 before descent. The posture recognition and compensation system also includes a controller 8, which is used to implement compensation and correction control of the movable beam.

[0032] In this embodiment, the pose recognition and compensation system further includes a monitoring unit; the monitoring unit includes displacement sensors 4 installed on the main cylinder 1 and four hydraulic compensation cylinders, used to collect the displacement of the corresponding cylinder piston rod. The monitoring unit also includes pressure sensors 5 installed on the four hydraulic compensation cylinders, used to collect the hydraulic oil pressure in the lower chamber of the cylinder.

[0033] The pose recognition and compensation system also includes a servo valve 6 (or a proportional valve) for controlling the flow and direction of hydraulic oil in the hydraulic compensation cylinder, and an oil source 7 for supplying oil to the hydraulic press.

[0034] Example 2

[0035] Please see Figure 2 This embodiment also provides a pose recognition method for the moving beam of a hydraulic press, which is applied to the pose recognition compensation system in Embodiment 1. The pose recognition method includes the following steps, namely S1 to S3.

[0036] S1: After the movable beam begins to descend, the pressure in the lower chamber of the hydraulic compensation cylinder is collected in real time by the pressure sensor. The pressure change time of the lower chamber when the movable beam contacts the four hydraulic compensation cylinders is recorded respectively, and the pressure change time difference of the diagonal hydraulic compensation cylinders is calculated.

[0037] Please see Figure 3 Because the pressure in the lower chamber changes significantly when the movable beam contacts the hydraulic compensating cylinder, this time is used to reflect the contact time between each compensating cylinder and the movable beam. It should be noted that during docking, the hydraulic compensating cylinder is suddenly subjected to a large downward load force, which is equivalent to squeezing the hydraulic oil in the lower chamber with a large force, thus causing the pressure in the lower chamber to increase.

[0038] In step S1, the formula for calculating the time difference of pressure change in the diagonal hydraulic compensation cylinder is:

[0039] In the formula, , , and The pressure change times in the lower chambers of hydraulic compensation cylinders 1, 2, 3, and 4 (i.e., 3a~3d in Example 1) are shown in sequence. The time difference of pressure change between diagonal hydraulic compensation cylinders 1 and 3. The time difference between the pressure change of diagonal hydraulic compensation cylinders 2 and 4.

[0040] S2: Using the diagonal hydraulic compensation cylinder that first contacts the moving beam as the reference cylinder, the displacement of the piston rod in the main cylinder and the reference cylinder during the corresponding pressure change time difference is collected by the displacement sensor, and the tilt angle of the moving beam along the diagonal direction is calculated accordingly.

[0041] Using the diagonal hydraulic compensation cylinders No. 1 (i.e., 3a in Example 1) and No. 3 (i.e., 3c in Example 1) that first contact the moving beam as the reference cylinder, in Internally collected reference cylinder piston rod displacement and the displacement of the master cylinder piston rod A relative displacement coordinate system of the movable beam with respect to the piston rod of the reference cylinder is established to obtain the displacement difference between the master cylinder and the reference cylinder. Approximating it as the chord length, the inclination angle of the movable beam in radians along the diagonal directions of hydraulic compensation cylinders 1 and 3 is: ;in Let the length of the movable beam be the length of its diagonal. , width is ,but ; Using the diagonal hydraulic compensation cylinders No. 2 (i.e., 3b in Example 1) and No. 4 (i.e., 3d in Example 1) that first contact the moving beam as the reference cylinder, in Internally collected reference cylinder piston rod displacement and the displacement of the master cylinder piston rod A relative displacement coordinate system of the movable beam with respect to the piston rod of the reference cylinder is established to obtain the displacement difference between the master cylinder and the reference cylinder. Approximating it as the chord length, the inclination angle of the movable beam in radians along the diagonal directions of hydraulic compensation cylinders No. 2 and No. 4 is: .

[0042] S3: Based on the tilt angle of the movable beam along the diagonal direction, calculate the tilt angle of the movable beam along the x-axis and y-axis of the horizontal coordinate system, thus identifying the pose state of the movable beam.

[0043] In step S3, the inclination angles of the movable beam along the x-axis and y-axis of the horizontal coordinate system are calculated as follows: according to:

[0044] We can obtain:

[0045] In the formula, Let x be the angle of inclination of the movable beam along the x-axis; Let be the angle of inclination of the movable beam along the y-axis.

[0046] Based on the obtained position and orientation of the movable beam, the cylinder that first comes into contact (the hydraulic compensation cylinder that first contacts the movable beam) is designated as the reference cylinder. The position compensation value of the reference cylinder is considered to be 0. The position compensation values ​​of the remaining three compensation cylinders are approximated as chord lengths, and the position compensation values ​​of the remaining three cylinders along the x-axis, y-axis, and diagonal direction of the reference cylinder are calculated respectively. , , :

[0047] In the formula, The compensation value is for the position of the cylinder that first comes into contact with the cylinder. The position compensation value of the hydraulic compensation cylinder along the x-axis direction of the cylinder that first contacts the cylinder; The position compensation value of the hydraulic compensation cylinder along the y-axis direction of the cylinder that first contacts the cylinder; This is the position compensation value for the hydraulic compensation cylinder located diagonally opposite the first contact cylinder.

[0048] Will , , , Arrange them in ascending order and assign values ​​to each hydraulic compensating cylinder (3a~3d) according to the contact sequence, and obtain the position compensation amount of each hydraulic compensating cylinder. ( i =1,2,3,4).

[0049] The four position compensation values ​​are compared, and the maximum value is denoted as . .in The pose recognition and compensation system will... With the preset maximum tilt threshold Comparison: When the tilt of the movable beam is small, the hydraulic compensation cylinder can be compensated and controlled in the next forming cycle by calculating the position and posture of the movable beam.

[0050] when When the tilt of the movable beam (2) is too large, it will have a certain impact on the quality of the formed part. After the system identifies the position and posture of the movable beam, it will stop automatically and output the position and posture of the movable beam.

[0051] Please see Figures 4 to 8 This embodiment also provides a compensation and correction control method for the moving beam of a hydraulic press, including the following steps: Step 1: Before the hydraulic press begins forming, initialize the pose recognition and compensation system and initialize the forming cycle counter to... The speed feedback control amount of the four hydraulic compensation cylinders in the pre-adjustment stage will be adjusted. Feedforward compensation voltage Initialize to 0, and extend the piston rod of the hydraulic compensation cylinder to the extended position. Initialize to the initial extension position of the system during the return phase. .

[0052] Step Two: The hydraulic press starts working, controlling the piston rod of the hydraulic compensation cylinder according to... Extend to the designated docking position, so that Entering the forming stage.

[0053] Step 3: During the forming process, the controller uses the above-mentioned pose recognition method to identify the pose state of the moving beam and calculate the position compensation amount of each hydraulic compensation cylinder. .

[0054] Step 4: Adjust the compensation amount for the four positions. The maximum value in the range is the maximum tilt value of the movable beam. With the preset maximum tilt threshold If a comparison is made, Then, based on the location compensation amount Calculate the control parameters for the next forming cycle, including: piston rod extension position. Speed ​​feedback control quantity during the pre-adjustment stage and feedforward compensation voltage .

[0055] like If the alarm is triggered, the machine will automatically stop and output the position and orientation status of the moving beam.

[0056] Step 5: Enter the pre-adjustment stage, using the speed feedback control amount obtained from the previous forming cycle. and feedforward compensation voltage Compensation control is performed to adjust the piston rod speed of the four hydraulic compensation cylinders so that the movable beam returns to a horizontal position before the leveling stage.

[0057] In this embodiment, the controller uses the obtained position compensation amount. Obtain the piston rod extension position before docking in the next forming cycle. Speed ​​feedback control value during the pre-adjustment phase and feedforward compensation voltage Value. The position of the piston rod extending from the hydraulic compensation cylinder. It is based on the amount of compensation. The piston rod extension position of each cylinder before docking is controlled so that the piston rod of each hydraulic compensation cylinder extends to a different length before docking according to the position of the moving beam. This ensures that the four cylinders can contact the moving beam synchronously as much as possible. If the initial extension length of the piston rod of each hydraulic compensation cylinder before docking is set to be... Then, the length of the piston rod extending from each cylinder before docking after compensation is: The timeframe is to be added after docking and before entering the leveling phase. During the pre-adjustment phase, after the movable beam has made full contact with all four hydraulic compensation cylinders, the valve port connected to the main cylinder opens and the movable beam falls under its own weight. Perform speed feedback control, and based on Perform valve port voltage feedforward compensation control, where, This refers to the effective area of ​​the lower chamber of the hydraulic compensation cylinder. For the valve's flow gain; This refers to the voltage-valve core displacement gain. By adjusting the speed of the piston rods of the four hydraulic compensation cylinders, the displacements of the four cylinders are made to be more consistent, thereby restoring the movable beam to a horizontal position before the leveling stage.

[0058] Step Six: Enter the leveling stage. After completing this forming process, return to Step Two.

[0059] The control method of this invention does not directly change the state of the movable beam. Instead, it controls the extension position of the piston rod of the hydraulic compensation cylinder to "accommodate" the tilt of the movable beam, only prompting manual correction when the initial tilt of the movable beam is large. The compensation stage is divided into two phases: one is to control the return position of the hydraulic compensation cylinder before docking, so that the movable beam docks synchronously with the compensation cylinder; the other is after compensation, because the piston rod extension positions of the hydraulic compensation cylinders are different, if the leveling stage is entered at this point, the movable beam will still be in a tilted state. Therefore, by controlling the positions of the three cylinders other than the lowest cylinder, the four compensation cylinders are made to be in the same horizontal position before the leveling stage.

[0060] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for recognizing the position of a moving beam in a hydraulic press, characterized in that, A pose recognition and compensation system for a hydraulic press includes a movable beam, a main cylinder mounted at the center of the upper surface of the movable beam for driving its descent, and four hydraulic compensation cylinders for supporting and adjusting the movable beam's pose during descent. The four hydraulic compensation cylinders are distributed symmetrically at the four corners of the movable beam relative to its center and are separated from the movable beam before descent. The pose recognition method includes the following steps: S1: After the movable beam begins to descend, the pressure in the lower chamber of the hydraulic compensation cylinder is collected in real time. The pressure change time of the lower chamber when the movable beam contacts the four hydraulic compensation cylinders is recorded respectively, and the pressure change time difference of the diagonal hydraulic compensation cylinders is calculated. S2: Using the diagonal hydraulic compensation cylinder that first contacts the moving beam as the reference cylinder, the piston rod displacement of the main cylinder and the reference cylinder during the corresponding pressure change time difference is collected respectively, and the tilt angle of the moving beam along the diagonal direction is calculated accordingly. S3: Based on the tilt angle of the movable beam along the diagonal direction, calculate the tilt angle of the movable beam along the x-axis and y-axis of the horizontal coordinate system, thus identifying the pose state of the movable beam.

2. The method for recognizing the position of the moving beam of a hydraulic press according to claim 1, characterized in that, In step S1, the formula for calculating the time difference of pressure change in the diagonal hydraulic compensation cylinder is: In the formula, , , and The times of pressure change in the lower chamber of hydraulic compensation cylinders 1, 2, 3, and 4 are shown in sequence. The time difference of pressure change between diagonal hydraulic compensation cylinders 1 and 3. The time difference of pressure change between diagonal hydraulic compensation cylinders 2 and 4; In step S2, the diagonal hydraulic compensation cylinder that first contacts the moving beam, either cylinder 1 or cylinder 3, is used as the reference cylinder. Internally collected reference cylinder piston rod displacement and the displacement of the master cylinder piston rod A relative displacement coordinate system of the movable beam with respect to the piston rod of the reference cylinder is established to obtain the displacement difference between the master cylinder and the reference cylinder. Approximating it as the chord length, the inclination angle of the movable beam in radians along the diagonal directions of hydraulic compensation cylinders 1 and 3 is: ;in Let the length of the movable beam be the length of its diagonal. , width is ,but ; Using the diagonal hydraulic compensation cylinders No. 2 and No. 4 that first contact the moving beam as the reference cylinder, in Internally collected reference cylinder piston rod displacement and the displacement of the master cylinder piston rod A relative displacement coordinate system of the movable beam with respect to the piston rod of the reference cylinder is established to obtain the displacement difference between the master cylinder and the reference cylinder. Approximating it as the chord length, the inclination angle of the movable beam in radians along the diagonal directions of hydraulic compensation cylinders No. 2 and No. 4 is: .

3. The method for recognizing the position of the moving beam of a hydraulic press according to claim 2, characterized in that, In step S3, the formula for calculating the inclination angle of the movable beam in radians along the x-axis and y-axis of the horizontal coordinate system is as follows: In the formula, Let x be the angle of inclination of the movable beam along the x-axis; Let be the angle of inclination of the movable beam along the y-axis.

4. The method for recognizing the position of the moving beam of a hydraulic press according to claim 3, characterized in that, In step S3, the position compensation values ​​of the four hydraulic compensation cylinders are also calculated using the following formula: In the formula, the cylinder that first comes into contact with the moving beam among the four hydraulic compensation cylinders is defined as the first contact cylinder. The compensation value is for the position of the cylinder that first comes into contact with the cylinder. The position compensation value of the hydraulic compensation cylinder along the x-axis direction of the cylinder that first contacts the cylinder; The position compensation value of the hydraulic compensation cylinder along the y-axis direction of the cylinder that first contacts the cylinder; This is the position compensation value for the hydraulic compensation cylinder located diagonally opposite the first contact cylinder.

5. A compensation and correction control method for a moving beam of a hydraulic press, applied to a posture recognition and compensation system of a hydraulic press, the system comprising a moving beam, a main cylinder mounted on the center of the upper surface of the moving beam for driving the moving beam to descend, and four hydraulic compensation cylinders for supporting the moving beam and adjusting its posture during descent, the four hydraulic compensation cylinders being distributed below the four corners of the moving beam and symmetrically distributed relative to the center of the moving beam, and being separated from the moving beam before descent; characterized in that, The compensation and correction control method includes the following steps: Step 1: Before the hydraulic press begins forming, initialize the pose recognition and compensation system and initialize the forming cycle counter to... The speed feedback control amount of the four hydraulic compensation cylinders in the pre-adjustment stage will be adjusted. Feedforward compensation voltage Initialize to 0, and extend the piston rod of the hydraulic compensation cylinder to the extended position. Initialize to the initial extension position of the system during the return phase. ;in , For time; Step Two: The hydraulic press starts working, controlling the piston rod of the hydraulic compensation cylinder according to... Extend to the designated docking position, so that Entering the forming stage; Step 3: During the forming process, the pose recognition method as described in claim 4 is used to identify the pose state of the moving beam and calculate the position compensation amount of each hydraulic compensation cylinder. ; Step 4: Adjust the compensation amount for the four positions. The maximum value in the range is the maximum tilt value of the movable beam. With the preset maximum tilt threshold If a comparison is made, Then, based on the location compensation amount Calculate the control parameters for the next forming cycle, including: piston rod extension position. Speed ​​feedback control quantity during the pre-adjustment stage and feedforward compensation voltage ; Step 5: Enter the pre-adjustment stage, using the speed feedback control amount obtained from the previous forming cycle. and feedforward compensation voltage Compensation control is performed to adjust the piston rod speed of the four hydraulic compensation cylinders so that the movable beam returns to a horizontal position before the leveling stage. Step Six: Enter the leveling stage. After completing this forming process, return to Step Two.

6. The compensation and correction control method for the moving beam of a hydraulic press according to claim 5, characterized in that, In step four, if If the alarm is triggered, the machine will automatically stop and output the position and orientation status of the moving beam.

7. A posture recognition and compensation system for a hydraulic press, characterized in that, The system includes a movable beam, a main cylinder mounted on the center of the upper surface of the movable beam for driving the movable beam to descend, and four hydraulic compensation cylinders for supporting the movable beam and adjusting its posture during descent. The four hydraulic compensation cylinders are distributed below the four corners of the movable beam and are symmetrically distributed with respect to the center of the movable beam. They are separated from the movable beam before descent. The posture recognition and compensation system also includes a controller for executing the compensation and correction control method as described in claim 5 to achieve compensation and correction control of the movable beam.

8. The posture recognition and compensation system for a hydraulic press according to claim 7, characterized in that, The pose recognition and compensation system also includes a monitoring unit; the monitoring unit includes displacement sensors installed on the main cylinder and four hydraulic compensation cylinders, used to collect the displacement of the piston rod of the corresponding cylinder.

9. The posture recognition and compensation system for a hydraulic press according to claim 8, characterized in that, The monitoring unit also includes pressure sensors installed on four hydraulic compensation cylinders for collecting hydraulic oil pressure in the lower chamber of the cylinder.

10. The posture recognition and compensation system for a hydraulic press according to claim 7, characterized in that, It also includes a servo valve and an oil source; the servo valve is used to control the flow and direction of hydraulic oil in the hydraulic compensation cylinder, and the oil source is used to supply oil to the hydraulic press.

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