Force position monitoring and analyzing system applied to press machine

Abstract

The invention discloses a force and position monitoring and analyzing system applied to a press machine, and relates to the technical field of force and position monitoring of the press machine, the force and position monitoring and analyzing system comprises a data acquisition module which is provided with a force sensor and a displacement sensor, and force and displacement data of the press machine in the punching process are monitored and acquired in real time through the force sensor and the displacement sensor. According to the force and position monitoring and analyzing system applied to the press machine, force and displacement data are accurately collected in real time through the data collecting module, the optimal action parameters of the press machine can be calculated, and the punching action of the press machine is accurately controlled; in this way, the key parameters in the stamping process can accurately reach the preset target, the product quality problem caused by parameter deviation is effectively avoided, and the quality stability and consistency of products are greatly improved; the system can quickly adjust action parameters of the press machine according to real-time monitoring and analysis results, so that the stamping process is always kept in an optimal state, time waste caused by links such as debugging and reworking is reduced, and the production efficiency is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of force and position monitoring of a press, and in particular to a force and position monitoring and analysis system applied to a press. Background Art

[0002] In modern manufacturing, presses, as an important processing equipment, are widely used in metal and non-metal sheet forming processes in many fields such as automobiles, aerospace, and electronics. With the continuous improvement of the manufacturing industry's requirements for product quality and production efficiency, precise control and performance optimization of presses have become increasingly critical. The stamping process involves complex mechanical behavior. When the press is stamping, factors such as the movement speed of the punch, the amount of pressure applied, and the deformation characteristics of the material affect each other and change over time. The changes in these parameters are directly related to the quality consistency and production efficiency of the stamped products. If the pressure control during the stamping process is inaccurate, it may lead to product size deviation, shape defects, and even mold damage. Improper stamping speed may cause problems such as excessive deformation and cracking of the material, seriously affecting product quality, while reducing production efficiency and increasing production costs.

[0003] Most traditional press control systems can only achieve basic motion control and lack the ability to accurately monitor and conduct in-depth analysis of key parameters such as force and displacement during the stamping process in real time. Although some existing monitoring systems can collect some data, they are insufficient in data processing accuracy, control algorithm optimization, and functional integrity. For example, some systems have a low data collection frequency and cannot accurately capture the rapid changes in the stamping process. In terms of control algorithms, the actual mechanical properties and complex working conditions of the press are not fully considered, resulting in inaccurate control instructions. Summary of the invention

[0004] In order to solve the above technical problems, the present invention is implemented through the following technical solutions: A force and position monitoring and analysis system applied to a press includes a data acquisition module: having a force and displacement sensor, monitoring and collecting the force and displacement data of the press in the stamping process in real time through the force and displacement sensor, and obtaining force and position data; and based on the GTM configuration acquisition module, collecting the force and displacement data of the force sensor and the displacement sensor, obtaining the force and position data, and converting it into an electrical signal; Control unit: adopts an industrial all-in-one machine to receive the electrical signals collected by the data acquisition module, analyze and process them, calculate the optimal action parameters of the press according to the preset algorithm and model, and generate control instructions based on the optimal action parameters. The control unit sends the control instructions to the press drive system to control the stamping action of the press; Communication module: supports I / O, TCP / IP, ModbusTCP, FTP communication protocols; used for data exchange with PLC / PC, and supports remote monitoring and control; Functional module: It has curve display function, and can display force / displacement curve, force / time curve, torque / time curve, and torque / angle curve in real time; it uses intuitive graphics to display parameter changes during the stamping process, so that operators can find abnormalities in time; it also has a curve saving function, which is used to save the curve of parameter changes during the stamping process, and the curve saving function also supports CSV and TXT data output formats; it is convenient for engineers to conduct subsequent analysis of the stamping process, trace quality problems and optimize the process; the functional module includes a calibration unit, including force sensor calibration, displacement sensor calibration, torque calibration, and angle calibration; it ensures the measurement accuracy of the sensor and the stamping accuracy.

[0005] Preferably, the data acquisition module collects the force and displacement data of the force and displacement sensor and converts it into an electrical signal: The force and displacement sensors installed at the connection area between the slide and the mold of the press and the force support structure of the press are used to collect the changes in the generated force and displacement during the stamping process, and generate original data reflecting the force and displacement of the press, namely, force and position data; the GTM configuration acquisition module is connected to the force and displacement sensor through a data transmission cable to ensure the stability and reliability of data transmission; since the GTM configuration acquisition module performs analog-to-digital conversion, namely, A / D conversion, on the received force and position data, based on the set sampling frequency of 1kHz, the analog signal will be sampled 1000 times per second, and the force and position data value of each sampling point will be converted into the corresponding digital signal value through the A / D converter to obtain the electrical signal corresponding to the force and position data, thereby converting the analog force and position data output by the force and displacement sensor into digital force and position data; then, the low-pass filter, high-pass filter or band-pass filter in the digital filtering algorithm is used to filter the electrical signal to remove the noise signal mixed in the data acquisition process to improve the data quality; then, the electrical signal is transmitted to the control unit through the industrial field bus for further analysis and processing to achieve precise control of the stamping process of the press.

[0006] Preferably, the control unit generates a control instruction based on the optimal action parameters: The industrial integrated machine of the control unit establishes a connection with the data acquisition module through industrial Ethernet or CAN bus, receives the electrical signal generated by the data acquisition module, performs decoding operation, obtains decoded data, and converts it into a digital data format that can be recognized and processed by the computer; then pre-processes the decoded data, including: data verification, removal of abnormal values, and obtains correct data; The preset algorithms and models built into the industrial integrated machine: The force-displacement-time relationship model based on Newtonian mechanics and the proportional-integral-differential control algorithm of the PID control algorithm for optimizing the stamping process are established to obtain the preset algorithm model; Based on the preset algorithm model, the correct data obtained after preprocessing is analyzed, including: by analyzing the force and displacement data of the press during the stamping process, and combining the time parameters, the current working state of the press is calculated; the working state includes the stamping speed and the force distribution; According to the current working state of the press obtained through analysis and combined with the target parameters of the stamping process, the industrial integrated machine calculates the optimal action parameters of the press through an algorithm, where the target parameters include the preset stamping pressure, target stamping depth, expected stamping speed range, and maximum allowable force deviation; if the force change trend during the current stamping process shows that the stamping pressure exceeds the allowable range, then based on the built-in algorithm, the industrial computer calculates the slider stroke speed and the pressure output parameters of the press that need to be adjusted to ensure that the stamping process can achieve the best effect and meet the process requirements; The optimal action parameters include the precise stroke position of the slider, the moving speed of the slider, the pressure output value of the press, and the stamping time interval; the optimal action parameters are obtained through comprehensive analysis of the collected data and algorithm calculation, which can enable the press to achieve the optimal working state under the current stamping task; Based on the calculated optimal motion parameters, the industrial integrated machine generates corresponding control instructions; and the control instructions exist in the form of digital signals, which are used to instruct the press drive system how to operate; If the calculation shows that the moving speed of the slider needs to be reduced, the control instruction will clearly indicate the specific value of the speed reduction and the time node of the adjustment; The industrial integrated machine sends the generated control instructions to the press drive system through its output interface; after receiving the control instructions, the press drive system adjusts the actions of various actuators of the press according to the requirements of the instructions; Preferably, the construction process of the preset algorithm model is: Based on the force-displacement-time relationship model of Newtonian mechanics, we build: The mass m of the punch of the press is obtained by directly measuring the actual mass of the punch; based on the friction and damping phenomena, the actual movement of the punch is measured under different stamping conditions, and the friction coefficient and damping coefficient are obtained by reverse calculation based on the theoretical formula. Combining the above factors, a mathematical model of the force-displacement-time relationship is established; the model F=m(d²x / dt²)+f(x,v)+d(x,v), where f(x,v) represents the friction force function related to displacement x and velocity v, and d(x,v) represents the damping force function related to displacement x and velocity v; Based on the proportional-integral-differential PID control algorithm model, build: For the proportional link P: the proportional link produces a control effect by proportionally amplifying the current error value e(t); its control effect uP(t)=Kp×e(t), where Kp is the proportional coefficient and e(t) is the difference between the actual value and the set value; For the integral link I: The integral link is used to eliminate the steady-state error of the system, and its control effect is uI(t)=Ki∫e(t)dt, where Ki is the integral coefficient; For the differential link D: The differential link produces a control effect according to the rate of change of the error; Its control action uD(t)=Kd(de(t) / dt), where Kd is the differential coefficient; Determine PID parameters Kp, Ki, Kd through experimental debugging and theoretical calculation; Based on the Ziegler-Nichols empirical tuning method, first set Ki and Kd to 0, increase Kp until the system oscillates with equal amplitude. The Kp value at this time is recorded as the critical proportional gain Kcr, and the oscillation period is recorded as Tcr. Then calculate Kp, Ki and Kd according to the empirical formula. When determining PID parameters, the characteristics of the press itself should be considered: the response speed and inertia of the press; for a press with a slow response speed, the proportional coefficient Kp should not be set too large to avoid overshoot of the system; for a press with a large inertia, the integral time constant needs to be appropriately increased to avoid integral saturation; Establish a PID control model: add the control effects of the three links of proportion, integration and differentiation to obtain the control signal of the PID control algorithm; The control signal u(t) is used to adjust the control command of the stamping action of the press, and the parameters are adjusted continuously according to the error feedback in the actual stamping process to achieve the optimal control of the stamping process of the press; The force-displacement-time relationship model based on Newtonian mechanics and the PID control algorithm model together constitute the preset algorithm model in the industrial all-in-one machine.

[0007] Preferably, the process of inversely calculating the friction coefficient and the damping coefficient by combining the theoretical formula is as follows: According to Newton's second law, the resultant force on the punch is Equal to quality With acceleration The product of In the actual case of friction and damping, the net force Equal to the applied force Subtract friction and damping force ; Based on the actual situation, friction and displacement and speed Related, it is expressed as: ; Damping force and speed and the damping coefficient The model is expressed as: ; Different stamping condition settings: Changing the punching speed: by controlling the drive system of the press; Set different punching speeds Conduct stamping test; Changing the punch load: changing the punch load by replacing the punch material with different thickness or hardness; Under each punching condition, a force sensor and a displacement sensor are used to record the force of the punch during the punching process. Over time The change data series and displacement Over time The change data series ; According to the displacement data series , the velocity is calculated by numerical difference method and acceleration Data series; According to the above theory and collected data, for each time point, the force balance equation is listed: ; According to actual physical conditions and experience, the friction function is and the damping force function the specific form of Assume the friction force function is: ; in, is the friction coefficient to be determined; Assume the damping force function is: ; in, is the damping coefficient to be determined; Substitute the set function into the force balance equation to obtain a set of equations about friction coefficient related parameters and damping coefficient related parameters; use the least squares method to solve the equations and obtain the friction coefficient related parameters Parameters related to damping coefficient The value of The friction coefficient related parameters and damping coefficient related parameters obtained are the specific parameters of the friction coefficient and damping coefficient obtained by reverse deduction under the assumed function form, thereby determining the friction force function and the damping force function , complete the construction of the mathematical model of force-displacement-time relationship.

[0008] Preferably, by analyzing the force and displacement data during the stamping process of the press and combining the time parameter, the process of calculating the current working state of the press is: From the correct data obtained after preprocessing, the data sequences related to force, displacement and corresponding timestamps are extracted respectively; the punching speed is calculated by the first-order derivative of the displacement data with respect to time; in the case of discrete data, the speed is calculated by the differential method; for the punching speed vi at a certain moment ti, it is calculated according to the formula vi≈(xi-xi-1) / (ti-ti-1), where i represents the i-th data point in the data sequence; the calculation is based on the changes of two adjacent time points and displacement points; multiple force sensors and displacement sensors are installed at different positions of the punch on the press and at the support points of the mold, and the force data collected by each sensor reflects the force condition of the part; the force data collected by each sensor is divided according to its installation position Classification; construct a force distribution model of the press according to the position information of the force sensor and displacement sensor and the collected force data; adopt the idea of ​​finite element analysis to discretize the press into multiple units, each unit corresponds to the monitoring area of ​​one or more sensors; calculate the force size and direction of each unit to obtain the force distribution data; integrate the calculated stamping speed and force distribution data, including: draw a stamping speed-time curve with time as the horizontal axis and stamping speed as the vertical axis to intuitively show the changing trend of the stamping speed; for the force distribution, draw a two-dimensional force distribution cloud map of the press to show the force size and distribution law of different parts; thereby determine the current working status of the press, including stamping speed and force distribution.

[0009] Preferably, according to the current working state of the press obtained by analysis and in combination with the target parameters of the stamping process, the process in which the industrial integrated machine calculates the optimal action parameters of the press through an algorithm is as follows: The industrial integrated machine first reads the target parameters of the stamping process from its internal storage or external input interface; obtains the current stamping pressure, current stamping depth and current stamping speed from the current working state of the press calculated based on the preset algorithm model, and compares the current stamping pressure with the preset stamping pressure; if the current stamping pressure is less than the preset stamping pressure, the industrial integrated machine calculates the pressure value that needs to be increased and the corresponding adjustment strategy according to the preset algorithm model; analyzes the current motion state and force condition of the punch through the force-displacement-time relationship model, and calculates the driving force proportional coefficient that needs to be increased according to the pressure deviation in combination with the proportional link in the PID control algorithm, thereby determining the parameters that need to be adjusted in the hydraulic system or mechanical transmission system of the press, such as the flow increase of the hydraulic pump or the torque increase value of the motor, so as to achieve the stamping pressure approaching the target parameters; Compare the current punching depth with the target punching depth; if the current punching depth does not reach the target punching depth, use the force-displacement-time relationship model to analyze the displacement trend and speed change of the punch; and calculate the punch stroke speed and duration that need to be adjusted based on the integral link in the PID control algorithm and the cumulative effect of the depth deviation; The current stamping speed is compared with the expected speed range; if the current speed exceeds the range, the differential link of the PID control algorithm is used to calculate the braking or acceleration control amount to be applied according to the speed change rate to stabilize it within the expected range; Analyze the difference between the current force distribution and the ideal force state. If there is an unbalanced force, for example, excessive force in a certain area causes mold wear or product deformation, the industrial all-in-one machine calculates the punch posture or pressure distribution strategy that needs to be adjusted based on the force distribution data and the mechanical structure model of the press. After comprehensive analysis and calculation of the punching pressure, punching depth, punching speed and force distribution, the industrial all-in-one machine determines a comprehensive set of optimal action parameters; the optimal action parameters include the precise stroke position adjustment of the punch, the target movement speed of the punch, the adjustment value of each pressure output point of the press, and the duration or pause time of the punching action.

[0010] Preferably, the function module displays the process of stamping process parameter changes in an intuitive graphic as follows: Force and displacement data processing: The data acquisition module continuously collects the force and displacement data during the stamping process of the press, records them as force-position data, and transmits them to the industrial integrated machine in the control unit; after receiving the force-position data, the control unit samples and sorts the force-position data at preset time intervals; the force and displacement data are sampled every 10 milliseconds, and the data are stored in a special cache area for subsequent drawing of force / displacement curves; Force and time data processing: For the force / time curve, the force data is also recorded at set time intervals and associated with the corresponding timestamps; and as the stamping process proceeds, the force data series and time series are continuously updated to form a complete data set of force changes over time; Torque and related data processing: In a press system with torque monitoring, the data acquisition module collects torque data and associates it with time or angle data as needed; In the display interface of the industrial integrated machine, a drawing area is opened to display different curves; set the coordinate axis. For the force / displacement curve, set the displacement as the horizontal axis and the force as the vertical axis; the force / time curve uses time as the horizontal axis and force as the vertical axis; the torque / time curve uses time as the horizontal axis and torque as the vertical axis; the torque / angle curve uses angle as the horizontal axis and torque as the vertical axis; according to the working parameter range of the press and historical data statistics, set the scale range of the coordinate axis to ensure that the parameter changes in the stamping process can be fully displayed; When the stamping process starts, the starting point of the curve is first drawn. In the force / displacement curve, a point is drawn at the corresponding coordinate axis position according to the force and displacement data collected at the initial moment. For the force / time curve, the stamping start moment is taken as the time zero point, and the corresponding force value point is drawn. As the stamping process progresses, new data points are continuously acquired at set time intervals and plotted on the curve; a new set of force and displacement data is acquired every 10 milliseconds, and a new point is drawn in the drawing area of ​​the force / displacement curve according to the coordinate position of the new data, and it is connected with the previous point to form a continuous curve; for the force / time curve, new force value points are continuously drawn extending to the right on the time axis to intuitively show the trend of force changes over time; Similarly, the torque / time curve and torque / angle curve are also drawn and updated in real time according to the rhythm of data collection. In the torque / time curve, the torque change curve is drawn as time increases. In the torque / angle curve, the torque and its corresponding relationship curve are drawn according to the change of the angle, and then the drawn curve is displayed in real time on the display screen of the industrial all-in-one machine. The operator can intuitively see the changes in force, displacement, and torque parameters during the stamping process. By observing the force / displacement curve, it can be understood how the force changes with the increase of displacement during the stamping process, and whether there is an abnormal force mutation or displacement deviation.

[0011] Preferably, the calibration unit calibrates the force sensor as follows: use a standard dynamometer to perform zero-position calibration, and read the output value of the force sensor when the press does not apply any external force, that is, when it is in a stationary and unloaded state; if the output value is not zero, record the offset value through the calibration software in the industrial all-in-one machine, and set the corresponding calibration parameters to correct the zero-position output of the force sensor to zero; apply different known force values ​​to the standard force source in turn; at each calibration point, record the actual force value Fs of the standard force source and the output value Fo of the force sensor; and calculate the calibration coefficient of the force sensor by the least squares method or linear regression algorithm; assume that the relationship between the output of the force sensor and the actual force value is Fo=kFs+b, where k is the sensitivity coefficient and b is the offset, solve the values ​​of k and b, and update them to the calibration parameters of the force sensor, thereby completing the precise calibration of the force sensor within the entire measuring range; The calibration process of the displacement sensor by the calibration unit is as follows: a laser interferometer is used as a standard displacement measuring device to perform zero-position calibration, including: when the slider or measuring part of the press is in the initial position, that is, the theoretical zero displacement position, the output value of the displacement sensor is read; if the value is not zero, a corresponding zero-position compensation value is set in the calibration software of the control unit to make the zero-position output of the displacement sensor match the actual zero displacement state; when performing range calibration: a standard displacement measuring device is used to move the relevant components of the press according to the set displacement interval, including: moving the slider every 10 mm from the initial position to the maximum displacement position; at each displacement point, the actual displacement value Ds of the standard displacement measuring device and the output value Do of the displacement sensor are recorded; the least squares method is also used to determine the calibration function relationship between the output value of the displacement sensor and the actual displacement value, and the calculation formula is Do=mDs+n, where m is the proportionality coefficient and n is the offset. The values ​​of m and n are solved and updated to the calibration parameters of the displacement sensor to complete the calibration of the displacement sensor.

[0012] Preferably, based on the torque measurement involved in the press, the process of the calibration unit for torque calibration is as follows: A standard torque calibrator is used as a standard torque source to perform zero-position and full-scale calibration, including: firstly, a zero-position calibration is performed, and when the torque sensor is not subjected to any torque, its output is adjusted to zero; then, the full-scale torque value of the torque sensor is applied to the standard torque source, and the standard torque value Ts and the output value To of the torque sensor are recorded, and the full-scale calibration coefficient is calculated; then, a multi-point calibration is performed, including: selecting multiple calibration points between the zero position and the full-scale, namely, 25%, 50%, and 75% of the scale points, respectively applying corresponding standard torques and recording data, and determining the calibration curve and parameters of the torque sensor through data fitting, and the calculation formula is To=pTs+q; wherein, p is the sensitivity coefficient, q is the offset, and the calibration parameters are updated to complete the calibration; Based on the angle measurement involved in the press, the calibration unit calibrates the angle as follows: Use a high-precision encoder or angle measuring instrument as a standard angle measuring device to perform zero position calibration, including: When the rotating part of the press is in the initial angle position, the output of the angle sensor is adjusted to zero; then the angle range is calibrated, including: gradually rotating the parts of the press corresponding to the angle, from the initial angle to the maximum angle range, recording the actual angle value As of the standard angle measuring equipment and the output value Ao of the angle sensor every 10°; determining the calibration relationship of the angle sensor through data processing, the calculation formula is Ao=rAs+s; wherein r is the proportional coefficient, s is the offset, updating the calibration parameters, realizing the calibration of the angle sensor, and ensuring its accuracy in the entire measurement angle range; calibrating the force sensor, displacement sensor, torque sensor and angle sensor through the above steps can effectively improve the measurement accuracy of the sensor, thereby ensuring the accuracy of the press stamping process and the stability of product quality.

[0013] The present invention provides a force position monitoring and analysis system applied to a press machine, which has the following beneficial effects: 1. The force and position monitoring and analysis system applied to the press machine accurately collects force and displacement data in real time through the data acquisition module, and converts it into electrical signals for transmission to the control unit. The control unit analyzes and processes the data based on the advanced preset algorithm model, calculates the optimal action parameters of the press, and thus accurately controls the stamping action of the press; this enables the key parameters in the stamping process to accurately reach the preset targets, effectively avoiding product quality problems caused by parameter deviations, and greatly improving the quality stability and consistency of the products.

[0014] 2. The force and position monitoring and analysis system applied to the press can quickly adjust the action parameters of the press according to the real-time monitoring and analysis results, so that the stamping process is always kept in the best state, reducing the time waste caused by debugging, rework and other links, and significantly improving production efficiency; during the stamping process, if it is found that the current stamping speed does not meet the expected speed range, the system can quickly calculate the braking or acceleration control amount to be applied through the differential link of the PID control algorithm, so that the stamping speed is stabilized in the optimal range in time, avoiding production delays caused by improper speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a flow chart of a force position monitoring and analysis system applied to a press machine according to the present invention; Figure 2 This is a flowchart of a partial operation process of the preset algorithm model in the present invention. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0017] like Figure 1 and Figure 2 As shown, the present invention provides a technical solution: a force position monitoring and analysis system applied to a press, comprising a data acquisition module: having a force sensor and a displacement sensor, monitoring and acquiring the force and displacement data of the press in a stamping process in real time through the force sensor and the displacement sensor, and obtaining force position data; and based on the GTM configuration acquisition module, collecting the force position data of the force sensor and the displacement sensor, and converting them into electrical signals; Control unit: adopts an industrial all-in-one machine to receive the electrical signals collected by the data acquisition module, analyze and process them, calculate the optimal action parameters of the press according to the preset algorithm and model, and generate control instructions based on the optimal action parameters. The control unit sends the control instructions to the press drive system to control the stamping action of the press; Communication module: supports I / O, TCP / IP, ModbusTCP, FTP communication protocols; used for data exchange with PLC / PC, and supports remote monitoring and control; Functional module: It has curve display function, which can display force / displacement curve, force / time curve, torque / time curve and torque / angle curve in real time; it can display parameter changes in the stamping process with intuitive graphics, so that operators can find abnormalities in time; it also has curve saving function, which is used to save the curve of parameter changes in the stamping process, and it also supports CSV and TXT data output formats; it is convenient for engineers to conduct subsequent analysis of the stamping process, trace quality problems and optimize the process; the functional module includes calibration unit, including force sensor calibration, displacement sensor calibration, torque calibration and angle calibration; it ensures the measurement accuracy of the sensor and the stamping accuracy; With recipe function, including: storage of 256*4 groups of programs; Support program setting function, each program group selects 8 tolerance judgment windows, 1 inflection point detection window, and 1 set of envelope curves; provide precise control and process standards for the stamping process, and improve product quality stability.

[0018] Preferably, the data acquisition module collects the force and position data of the force sensor and the displacement sensor and converts them into electrical signals: The force sensors and displacement sensors installed at the connection area between the slide and the mold of the press and the force support structure of the press are used to collect the changes in the force and displacement generated during the stamping process, and generate original data reflecting the force and displacement of the press, namely, force and position data; the GTM configuration acquisition module is connected to the force sensor and displacement sensor through a data transmission cable to ensure the stability and reliability of data transmission; since the GTM configuration acquisition module performs analog-to-digital conversion, namely A / D conversion, on the received force and position data, based on the set sampling frequency of 1kHz, the analog signal will be sampled 1000 times per second Similarly, the force position data value of each sampling point is converted into a corresponding digital signal value through an A / D converter to obtain an electrical signal corresponding to the force position data, thereby converting the analog force position data output by the force sensor and the displacement sensor into force position data in digital form; then, a low-pass filter, a high-pass filter or a band-pass filter in a digital filter algorithm is used to filter the electrical signal to remove the noise signal mixed in during the data acquisition process to improve the data quality; then, the electrical signal is transmitted to the control unit through the industrial field bus for further analysis and processing to achieve precise control of the stamping process of the press; Among them, for convenience, the force sensor and position sensor can also be integrated based on strain gauge technology to form a force displacement sensor to collect force and position data; the working principle is: when external force acts on the sensor, the resistance value of the strain gauge changes, and the magnitude of the force is calculated by measuring this change; at the same time, the displacement measurement mechanism inside the sensor can provide position information.

[0019] Preferably, the control unit generates a control instruction based on the optimal action parameters: The industrial integrated machine of the control unit establishes a connection with the data acquisition module through industrial Ethernet or CAN bus, receives the electrical signal generated by the data acquisition module, performs decoding operation, obtains decoded data, and converts it into a digital data format that can be recognized and processed by the computer; then pre-processes the decoded data, including: data verification, removal of abnormal values, and obtains correct data; if error codes appear during data transmission, these errors can be found and corrected through the verification algorithm; for abnormal data points that obviously deviate from the normal range, filtering algorithms or methods based on statistical analysis are used to identify and process them; The preset algorithms and models built into the industrial integrated machine: The force-displacement-time relationship model based on Newtonian mechanics and the proportional-integral-differential control algorithm of the PID control algorithm for optimizing the stamping process are established to obtain the preset algorithm model; Based on the preset algorithm model, the correct data obtained after preprocessing is analyzed, including: by analyzing the force and displacement data of the press during the stamping process, and combining the time parameters, the current working state of the press is calculated; the working state includes the stamping speed and the force distribution; According to the current working state of the press obtained through analysis and combined with the target parameters of the stamping process, the industrial integrated machine calculates the optimal action parameters of the press through an algorithm, where the target parameters include the preset stamping pressure, target stamping depth, expected stamping speed range, and maximum allowable force deviation; if the force change trend during the current stamping process shows that the stamping pressure exceeds the allowable range, then based on the built-in algorithm, the industrial computer calculates the slider stroke speed and the pressure output parameters of the press that need to be adjusted to ensure that the stamping process can achieve the best effect and meet the process requirements; The optimal action parameters include the precise stroke position of the slider, the moving speed of the slider, the pressure output value of the press, and the stamping time interval; the optimal action parameters are obtained through comprehensive analysis of the collected data and algorithm calculation, which can enable the press to achieve the optimal working state under the current stamping task; Based on the calculated optimal action parameters, the industrial integrated machine generates corresponding control instructions; and the control instructions exist in the form of digital signals, which are used to instruct the press drive system how to operate; If the calculation shows that the moving speed of the slider needs to be reduced, the control instruction will clearly indicate the specific value of the speed reduction and the time node of the adjustment; The industrial all-in-one machine sends the generated control instructions to the press drive system through its output interface; after receiving the control instructions, the press drive system adjusts the actions of various actuators of the press according to the requirements of the instructions; for example, the drive motor adjusts the speed according to the instructions, and the hydraulic system adjusts the pressure and flow according to the instructions, thereby accurately controlling the stamping action of the press and ensuring that the stamping process is carried out according to the optimal action parameters.

[0020] Preferably, the construction process of the preset algorithm model is: Based on the force-displacement-time relationship model of Newtonian mechanics, we build: The mass m of the punch of the press is obtained by directly measuring the actual mass of the punch; based on the friction and damping phenomena, the actual movement of the punch is measured under different stamping conditions, and the friction coefficient and damping coefficient are obtained by reverse calculation based on the theoretical formula. Combining the above factors, a mathematical model of the force-displacement-time relationship is established; the model F=m(d²x / dt²)+f(x,v)+d(x,v), where f(x,v) represents the friction force function related to displacement x and velocity v, and d(x,v) represents the damping force function related to displacement x and velocity v; Based on the proportional-integral-differential PID control algorithm model, build: For the proportional link P: the proportional link produces a control effect by proportionally amplifying the current error value e(t); its control effect uP(t)=Kp×e(t), where Kp is the proportional coefficient and e(t) is the difference between the actual value and the set value; during the stamping process of the press, when there is a deviation between the actual value of the stamping pressure and the set value, the proportional link will generate a control signal based on this deviation. The larger the deviation, the stronger the control signal; For the integral link I: the integral link is used to eliminate the steady-state error of the system, and its control effect is uI(t)=Ki∫e(t)dt, where Ki is the integral coefficient; for the press, if there is a constant deviation in the stamping process, such as the stamping pressure is always a little bit smaller, the integral link will continuously increase the control signal as time accumulates until the steady-state deviation is eliminated; For the differential link D: The differential link produces a control effect according to the rate of change of the error; Its control effect is uD(t)=Kd(de(t) / dt), where Kd is the differential coefficient. During the stamping process of the press, when the rate of change of the stamping pressure is too fast, such as a sudden increase or decrease, the differential link will generate a control signal to suppress this rapid change and make the stamping process more stable. Determine PID parameters Kp, Ki, Kd through experimental debugging and theoretical calculation; Based on the Ziegler-Nichols empirical tuning method, first set Ki and Kd to 0, increase Kp until the system oscillates with equal amplitude, the Kp value at this time is recorded as the critical proportional gain Kcr, and the oscillation period is recorded as Tcr; then calculate Kp, Ki and Kd according to the empirical formula; for example, in the stamping control of a press machine, this method is used to determine the PID parameters that enable the stamping pressure and displacement parameters to reach the set values ​​quickly and stably; When determining PID parameters, the characteristics of the press itself should be considered: the response speed and inertia of the press; for a press with a slow response speed, the proportional coefficient Kp should not be set too large to avoid overshoot of the system; for a press with a large inertia, the integral time constant needs to be appropriately increased to avoid integral saturation; Establish a PID control model: add the control effects of the three links of proportion, integration and differentiation to obtain the control signal of the PID control algorithm; Control signal calculation formula: u(t)=uP(t)+uI(t)+uD(t)=Kp×e(t)+Ki∫e(t)dt+Kd(de(t) / dt); The control signal u(t) is used to adjust the control command of the stamping action of the press, and the parameters are adjusted continuously according to the error feedback in the actual stamping process to achieve the optimal control of the stamping process of the press; The force-displacement-time relationship model based on Newtonian mechanics and the PID control algorithm model together constitute the preset algorithm model in the industrial all-in-one machine.

[0021] Preferably, the process of inversely calculating the friction coefficient and the damping coefficient by combining the theoretical formula is as follows: According to Newton's second law, the resultant force on the punch is Equal to quality With acceleration The product of Right now ; In the actual case of friction and damping, the net force Equal to the applied force Subtract friction and damping force ; That is, the formula for calculating the resultant force is: ; Friction With positive pressure and friction coefficient In the case of horizontal punching, the positive pressure is equal to the weight of the punch. , the friction model is: ; Based on the actual situation, friction and displacement and speed Related, it is expressed as: ; Damping force and speed and the damping coefficient The model is expressed as: ; Different stamping condition settings: Changing the punching speed: by controlling the drive system of the press; Set different punching speeds Conduct stamping test; For example, at low, medium, and high speeds: Stamping is carried out under the following conditions; Changing the punch load: changing the punch load by replacing the punch material with different thickness or hardness; For example, using a thickness of Stamping with the same material or using materials of different hardness , ; Under each punching condition, a force sensor and a displacement sensor are used to record the force of the punch during the punching process. Over time The change data series and displacement Over time The change data series ; According to the displacement data series , the velocity is calculated by numerical difference method and acceleration Data series; According to the above theory and collected data, for each time point, the force balance equation is listed: ; According to actual physical conditions and experience, the friction function is and the damping force function the specific form of Assume the friction force function is: ; in, is the friction coefficient to be determined; Assume the damping force function is: ; in, is the damping coefficient to be determined; Substituting the set function into the force balance equation, a set of equations about friction coefficient related parameters and damping coefficient related parameters are obtained; At different time points There are equations: ; ; Use the least squares method to solve the equations and obtain the friction coefficient related parameters Parameters related to damping coefficient The value of The friction coefficient related parameters and damping coefficient related parameters obtained are the specific parameters of the friction coefficient and damping coefficient obtained by reverse deduction under the assumed function form, thereby determining the friction force function and the damping force function , complete the construction of the mathematical model of force-displacement-time relationship.

[0022] Preferably, by analyzing the force and displacement data during the stamping process of the press and combining the time parameter, the process of calculating the current working state of the press is: From the correct data obtained after preprocessing, extract the data sequences related to force, displacement and corresponding timestamps respectively; the force data sequence is a series of force values ​​[F1, F2, F3, …, Fn] collected at different time points, the corresponding time series is [t1, t2, t3, …, tn], and the displacement data sequence is [x1, x2, x3, …, xn]; the punching speed is calculated by the first-order derivative of the displacement data with respect to time; in the case of discrete data, the difference method is used to calculate the speed; for the punching speed vi at a certain time ti, it is calculated according to the formula vi≈(xi-xi-1) / (ti-ti-1), where i represents the i-th data point in the data sequence; the calculation is based on the changes of two adjacent time points and displacement points situation; it is known that the displacement at time t1 is x1, and the displacement at time t2 is x2, then the average stamping speed v2 in the time period from t1 to t2 is ≈ (x2-x1) / (t2-t1); by performing such calculations on the entire data sequence in turn, a series of stamping speed values ​​at different time points are obtained, thereby depicting the stamping speed change curve over time; multiple force sensors and displacement sensors are installed at different positions of the punch on the press and at the support points of the mold, and the force data collected by each sensor reflects the force situation of the part; the force data collected by each sensor are classified and sorted according to their installation positions; for example, sensors S1, S2, and S3 are installed at positions A, B, and C of the press respectively, and the force data sequences collected by them are classified They are [F1A, F2A, F3A, …, FnA], [F1B, F2B, F3B, …, FnB], [F1C, F2C, F3C, …, FnC] respectively; according to the position information of the force sensor and displacement sensor and the collected force data, the force distribution model of the press is constructed; the idea of ​​finite element analysis is adopted to discretize the press into multiple units, each unit corresponds to the monitoring area of ​​one or more sensors; the force magnitude and direction of each unit are calculated to obtain the force distribution data; for a certain time ti, unit 1 corresponds to the area where sensor S1 is located, the force Fi1 of unit 1 is = Fia, unit 2 corresponds to the area where sensor S2 is located, the force Fi2 of unit 2 is = Fib, and so on; through calculation, we get The force distribution of the press at different times, determine the areas with greater force and the areas with less force, as well as the force balance of the entire press; integrate the calculated stamping speed and force distribution data, including: drawing a stamping speed-time curve with time as the horizontal axis and stamping speed as the vertical axis to intuitively show the changing trend of the stamping speed; for the force distribution, draw a two-dimensional force distribution cloud map of the press to show the force size and distribution law of different parts; for example, within a time period, by observing the stamping speed curve, it can be found that the stamping speed fluctuates at a certain moment, and combined with the force distribution cloud map, it can be analyzed that the abnormal force in a certain area causes the unstable working state of the press, thereby providing a basis for subsequent control adjustments;Through such comprehensive analysis, the current working status of the press can be determined, including the punching speed and force distribution.

[0023] Preferably, according to the current working state of the press obtained by analysis and in combination with the target parameters of the stamping process, the process in which the industrial integrated machine calculates the optimal action parameters of the press through an algorithm is as follows: The industrial integrated machine first reads the target parameters of the stamping process from its internal storage or external input interface; for a specific stamping product, the preset stamping pressure is 500kN, the target stamping depth is 10mm, the expected stamping speed is between 50-100mm / s, and the force deviation does not exceed ±5%; these parameters are set and stored in the industrial integrated machine before the stamping task begins, or can be adjusted during the production process through the human-computer interaction interface; The current stamping pressure, current stamping depth and current stamping speed are obtained from the current working state of the press calculated based on the preset algorithm model, and the current stamping pressure is compared with the preset stamping pressure; if the current stamping pressure is less than the preset stamping pressure, the pressure value to be increased and the corresponding adjustment strategy are calculated by the industrial all-in-one machine according to the preset algorithm model; the current motion state and force condition of the punch are analyzed by the force-displacement-time relationship model, and the proportional link in the PID control algorithm is combined to calculate the driving force proportional coefficient to be increased according to the pressure deviation, so as to determine the parameters that need to be adjusted in the hydraulic system or mechanical transmission system of the press, such as the flow increase of the hydraulic pump or the torque increase value of the motor, so as to achieve the stamping pressure close to the target parameters; Compare the current punching depth with the target punching depth; if the current punching depth does not reach the target punching depth, use the force-displacement-time relationship model to analyze the displacement trend and speed change of the punch; and calculate the punch stroke speed and duration that need to be adjusted based on the integral link in the PID control algorithm and the cumulative effect of the depth deviation; For example, if the punching depth is insufficient, the speed of the punch needs to be increased, but at the same time, the speed must not exceed the upper limit of the expected punching speed range; by analyzing the impact of speed on depth and the current force conditions, determine a suitable speed adjustment, such as adjusting the current punching speed from 60mm / s to 70mm / s, and calculate the remaining time required to reach the target depth at this speed, which is used as the parameter basis for controlling the continued movement of the punch; The current punching speed is compared with the expected speed range; if the current speed exceeds the range, the differential link of the PID control algorithm is used to calculate the braking or acceleration control amount to be applied according to the speed change rate to stabilize it within the expected range; for example, if the current punching speed is 110mm / s, which exceeds the expected upper limit of 100mm / s, the differential link is used to calculate the control signal generated by the excessive speed, adjust the drive system of the press, and reduce the speed of the punch; Analyze the difference between the current force distribution and the ideal force state. If there is an unbalanced force, for example, a certain area is subjected to excessive force, resulting in mold wear or product deformation; the punch posture or pressure distribution strategy that needs to be adjusted is calculated through the industrial all-in-one machine based on the force distribution data and the mechanical structure model of the press; for example, by changing the inclination angle of the punch or adjusting the pressure output ratio of different parts, the force of the press can be made more uniform; it involves the calculation of the coordinated control parameters of multiple actuators, such as the coordinated control parameter calculation of multiple hydraulic cylinders or motors, to determine the force or displacement that needs to be adjusted for each actuator to optimize the force distribution; After comprehensive analysis and calculation of the stamping pressure, stamping depth, stamping speed and force distribution, the industrial all-in-one machine determines a comprehensive set of optimal action parameters; the optimal action parameters include the precise stroke position adjustment of the punch, the target movement speed of the punch, the adjustment value of each pressure output point of the press, and the duration or pause time of the stamping action; for example: it is determined that the punch needs to move forward another 3mm, the speed is adjusted to 80mm / s, the pressure of a hydraulic cylinder in the hydraulic system is increased by 50kN, and it pauses for 0.5s after reaching the target depth; these optimal action parameters will be sent to the press drive system as control instructions to achieve precise optimization control of the press stamping action to ensure that the stamping process meets the process requirements and achieves optimal performance.

[0024] Preferably, the function module displays the process of stamping process parameter changes in an intuitive graphic as follows: Force and displacement data processing: The data acquisition module continuously collects the force and displacement data during the stamping process of the press, records them as force-position data, and transmits them to the industrial integrated machine in the control unit; after receiving the force-position data, the control unit samples and sorts the force-position data at preset time intervals; the force and displacement data are sampled every 10 milliseconds, and the data are stored in a special cache area for subsequent drawing of force / displacement curves; Force and time data processing: For the force / time curve, the force data is also recorded at set time intervals and associated with the corresponding timestamps; and as the stamping process proceeds, the force data series and time series are continuously updated to form a complete data set of force changes over time; Torque and related data processing: In a press system with torque monitoring, the data acquisition module collects torque data and associates it with time or angle data as needed; for example, when monitoring the torque / time curve, the torque value is recorded in chronological order; when drawing the torque / angle curve, the angle data is obtained through the sensor and corresponds to the torque data one by one to build a data sequence of the relationship between torque and angle; In the display interface of the industrial integrated machine, a drawing area is opened to display different curves; set the coordinate axis. For the force / displacement curve, set the displacement as the horizontal axis and the force as the vertical axis; the force / time curve uses time as the horizontal axis and force as the vertical axis; the torque / time curve uses time as the horizontal axis and torque as the vertical axis; the torque / angle curve uses angle as the horizontal axis and torque as the vertical axis; according to the working parameter range of the press and historical data statistics, set the scale range of the coordinate axis to ensure that the parameter changes in the stamping process can be fully displayed; for example, if the maximum stamping pressure of the press is 1000kN, the scale of the force axis can be set to 0-1200kN, so as to leave a certain margin to observe data fluctuations; When the stamping process starts, the starting point of the curve is first drawn. In the force / displacement curve, a point is drawn at the corresponding coordinate axis position according to the force and displacement data collected at the initial moment. For the force / time curve, the stamping start moment is taken as the time zero point, and the corresponding force value point is drawn. As the stamping process progresses, new data points are continuously acquired at set time intervals and plotted on the curve; a new set of force and displacement data is acquired every 10 milliseconds, and a new point is drawn in the drawing area of ​​the force / displacement curve according to the coordinate position of the new data, and it is connected with the previous point to form a continuous curve; for the force / time curve, new force value points are continuously drawn extending to the right on the time axis to intuitively show the trend of force changes over time; Similarly, the torque / time curve and torque / angle curve are also drawn and updated in real time according to the rhythm of data collection. In the torque / time curve, the torque change curve is drawn as time increases. In the torque / angle curve, the torque and its corresponding relationship curve are drawn according to the change of the angle, and then the drawn curve is displayed in real time on the display screen of the industrial all-in-one machine. The operator can intuitively see the changes in force, displacement, and torque parameters during the stamping process. By observing the force / displacement curve, it can be understood how the force changes with the increase of displacement during the stamping process, and whether there is an abnormal force mutation or displacement deviation.

[0025] Preferably, the calibration unit calibrates the force sensor as follows: Use a standard dynamometer to perform zero-position calibration. When the press does not apply any external force, that is, when it is in a stationary and unloaded state, read the output value of the force sensor. If the output value is not zero, record the offset value through the calibration software in the industrial all-in-one machine, and set the corresponding calibration parameters to correct the zero-position output of the force sensor to zero. For example, if the output of the force sensor is 5N when there is no load, set the zero-position compensation value to -5N in the software, so that the force value will be calculated from the corrected zero position in subsequent measurements. Apply different known force values ​​to the standard force source in turn, such as the range of the press force sensor is 1000. kN, multiple calibration points such as 0kN, 200kN, 400kN, 600kN, 800kN and 1000kN can be selected; at each calibration point, the actual force value Fs of the standard force source and the output value Fo of the force sensor are recorded; and the calibration coefficient of the force sensor is calculated by the least square method or linear regression algorithm; the relationship between the output of the force sensor and the actual force value is assumed to be Fo=kFs+b, where k is the sensitivity coefficient and b is the offset, the values ​​of k and b are solved and updated to the calibration parameters of the force sensor, thereby completing the accurate calibration of the force sensor within the entire measuring range; The calibration process of the calibration unit for the displacement sensor is as follows: A laser interferometer is used as a standard displacement measuring device to perform zero-position calibration, including: when the slider or measuring part of the press is in the initial position, that is, the theoretical zero displacement position, read the output value of the displacement sensor; if the value is not zero, set the corresponding zero-position compensation value in the calibration software of the control unit to make the zero-position output of the displacement sensor match the actual zero displacement state; for example, the initial output of the displacement sensor is 0.1mm, and the zero-position compensation is set to -0.1mm in the software; when performing range calibration: use a standard displacement measuring device to move the relevant components of the press according to the set displacement interval, including: move the slider every 10mm from the initial position to the maximum displacement position; at each displacement point, record the actual displacement value Ds of the standard displacement measuring device and the output value Do of the displacement sensor; also use the least squares method to determine the calibration function relationship between the output value of the displacement sensor and the actual displacement value, the calculation formula is Do=mDs+n, where m is the proportionality coefficient and n is the offset, solve the values ​​of m and n and update them to the calibration parameters of the displacement sensor to complete the calibration of the displacement sensor.

[0026] Preferably, based on the torque measurement involved in the press, the process of the calibration unit for torque calibration is as follows: A standard torque calibrator is used as a standard torque source to perform zero-position and full-scale calibration, including: firstly, a zero-position calibration is performed, and when the torque sensor is not subjected to any torque, its output is adjusted to zero; then, the full-scale torque value of the torque sensor is applied to the standard torque source, and the standard torque value Ts and the output value To of the torque sensor are recorded, and the full-scale calibration coefficient is calculated; then, a multi-point calibration is performed, including: selecting multiple calibration points between the zero position and the full-scale, namely, 25%, 50%, and 75% of the scale points, respectively applying corresponding standard torques and recording data, and determining the calibration curve and parameters of the torque sensor through data fitting, and the calculation formula is To=pTs+q; wherein, p is the sensitivity coefficient, q is the offset, and the calibration parameters are updated to complete the calibration; Based on the angle measurement involved in the press, the calibration unit calibrates the angle as follows: Use a high-precision encoder or angle measuring instrument as a standard angle measuring device to perform zero position calibration, including: When the rotating part of the press is in the initial angle position, the output of the angle sensor is adjusted to zero; for example, if the initial output of the angle sensor is 5°, the zero position compensation is set to -5° in the control unit; then the angle range is calibrated, including: gradually rotating the parts of the press corresponding to the angle, from the initial angle to the maximum angle range, recording the actual angle value As of the standard angle measuring device and the output value Ao of the angle sensor every 10°; determining the calibration relationship of the angle sensor through data processing, the calculation formula is Ao=rAs+s; wherein r is the proportional coefficient, s is the offset, and the calibration parameters are updated to realize the calibration of the angle sensor to ensure its accuracy in the entire measurement angle range; calibrating the force sensor, displacement sensor, torque sensor and angle sensor through the above steps can effectively improve the measurement accuracy of the sensor, thereby ensuring the accuracy of the press stamping process and the stability of product quality.

[0027] The calibration unit can accurately calibrate force sensors, displacement sensors, torque sensors and angle sensors, including zero calibration, full-scale calibration and multi-point calibration. Through these calibration operations, the errors of the sensors during the measurement process are effectively eliminated, ensuring the accuracy of the sensor measurements and providing a reliable data basis for the entire system, thereby further ensuring the stability of the press stamping accuracy and product quality.

[0028] It should be further explained that, in the specific implementation process, the data acquisition module accurately collects force and displacement data in real time, converts them into electrical signals and transmits them to the control unit. The control unit analyzes and processes the data based on the advanced preset algorithm model, calculates the optimal action parameters of the press, and thus accurately controls the stamping action of the press; this enables the key parameters in the stamping process to accurately reach the preset targets, effectively avoids product quality problems caused by parameter deviations, and greatly improves the quality stability and consistency of the products; The system can quickly adjust the action parameters of the press according to the real-time monitoring and analysis results, so that the stamping process is always kept in the best state, reducing the time waste caused by debugging, rework and other links, and significantly improving production efficiency; during the stamping process, if it is found that the current stamping speed does not meet the expected speed range, the system can quickly calculate the braking or acceleration control amount to be applied through the differential link of the PID control algorithm, so that the stamping speed is stabilized in the optimal range in time, avoiding production delays caused by improper speed.

[0029] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. A force position monitoring and analysis system for a press machine, characterized in that: include: Data acquisition module: It has force sensors and displacement sensors, which are used to monitor and collect the force and displacement data of the press in the stamping process in real time to obtain force and position data; Based on the GTM configuration acquisition module, the force and displacement data of the force sensor and displacement sensor are collected and converted into electrical signals; Control unit: an industrial integrated machine is used to receive the electrical signals collected by the data acquisition module, and analyzes and processes them, calculates the optimal action parameters of the press according to the preset algorithm and model, and generates control instructions based on the optimal action parameters. The control unit sends the control instructions to the press drive system to control the stamping action of the press; Communication module: supports I / O, TCP / IP, ModbusTCP, FTP communication protocols; used for data exchange with PLC / PC, and supports remote monitoring and control; Functional module: It has curve display function, which can display force / displacement curve, force / time curve, torque / time curve and torque / angle curve in real time; it can show parameter changes during stamping process; it also has curve saving function, which is used to save the curve of parameter changes during stamping process, and it also supports CSV and TXT data output formats; the functional module includes calibration unit, including force sensor calibration, displacement sensor calibration, torque calibration and angle calibration.

2. The force position monitoring and analysis system for a press machine according to claim 1, characterized in that: The data acquisition module collects the force and displacement data of the force sensor and the displacement sensor and converts them into electrical signals: The force sensor and displacement sensor installed at the connection area between the slide and the mold of the press and the force support structure of the press are used to collect the changes in the force and displacement generated during the stamping process, and generate original data reflecting the force and displacement of the press, namely, force-position data; the GTM configuration acquisition module is connected to the force sensor and the displacement sensor respectively through data transmission cables. Since the GTM configuration acquisition module performs analog-to-digital conversion, namely, A / D conversion, on the received force-position data, based on the set sampling frequency of 1kHz, the force-position data value of each sampling point is converted into a corresponding digital signal value through an A / D converter to obtain an electrical signal corresponding to the force-position data; then, the low-pass filter, high-pass filter or band-pass filter in the digital filtering algorithm is used to filter the electrical signal to remove the noise signal mixed in the data acquisition process; The electrical signal is then transmitted to the control unit via the industrial field bus.

3. The force position monitoring and analysis system for a press machine according to claim 2, characterized in that: The process of the control unit generating control instructions based on the optimal action parameters: The industrial integrated machine of the control unit is connected to the data acquisition module via industrial Ethernet or CAN bus to receive the electrical signal generated by the data acquisition module; And perform decoding operation to obtain decoded data; The decoded data is then preprocessed, including: data verification, removal of outliers, and obtaining correct data; The preset algorithms and models built into the industrial integrated machine: The preset algorithm model is obtained based on the force-displacement-time relationship model of Newtonian mechanics and the proportional-integral-differential control algorithm of PID; Based on the preset algorithm model, the correct data obtained after preprocessing is analyzed, including: by analyzing the force and displacement data of the press during the stamping process, and combining the time parameters, the current working state of the press is calculated; the working state includes the stamping speed and the force distribution; According to the current working state of the press obtained through analysis and combined with the target parameters of the stamping process, the industrial integrated machine calculates the optimal action parameters of the press through an algorithm, where the target parameters include the preset stamping pressure, target stamping depth, expected stamping speed range, and maximum allowable force deviation; The optimal action parameters include the precise stroke position of the slide, the moving speed of the slide, the pressure output value of the press, and the time interval between stamping; Based on the calculated optimal action parameters, the industrial integrated machine generates corresponding control instructions; The industrial all-in-one machine sends the generated control instructions to the press drive system through its output interface; after receiving the control instructions, the press drive system adjusts the actions of various execution components of the press according to the requirements of the instructions.

4. The force position monitoring and analysis system for a press machine according to claim 3 is characterized in that: The construction process of the preset algorithm model: Based on the force-displacement-time relationship model of Newtonian mechanics, we build: The mass m of the punch of the press is obtained by directly measuring the actual mass of the punch; based on the friction and damping phenomena, the actual movement of the punch is measured under different stamping conditions, and the friction coefficient and damping coefficient are obtained by reverse deduction based on the theoretical formula, and a mathematical model of the force-displacement-time relationship is established; the model F=m(d²x / dt²)+f(x,v)+d(x,v), where f(x,v) represents the friction force function related to displacement x and velocity v, and d(x,v) represents the damping force function related to displacement x and velocity v; Based on the proportional-integral-differential PID control algorithm model, build: For the proportional link P: the proportional link produces a control effect by proportionally amplifying the current error value e(t); its control effect uP(t)=Kp×e(t), where Kp is the proportional coefficient and e(t) is the difference between the actual value and the set value; For the integral link I: the integral link is used to eliminate the steady-state error of the system, and its control action uI(t)=Ki∫e(t)dt, where Ki is the integral coefficient; for the differential link D: the differential link produces a control action according to the rate of change of the error; its control action uD(t)=Kd(de(t) / dt), where Kd is the differential coefficient; the PID parameters Kp, Ki, and Kd are determined through experimental debugging and theoretical calculation; based on the Ziegler-Nichols empirical tuning method, first set Ki and Kd to 0, increase Kp until the system oscillates with equal amplitude, and the Kp value at this time is recorded as the critical proportional gain Kcr, and the oscillation period is recorded as Tcr; then calculate Kp, Ki, and Kd according to the empirical formula; When determining the PID parameters, the characteristics of the press itself are taken into consideration: the response speed and inertia of the press; a PID control model is established: the control effects of the three links of proportion, integration and differentiation are added together to obtain the control signal of the PID control algorithm; the control instructions of the stamping action of the press are adjusted through the control signal; the force-displacement-time relationship model based on Newtonian mechanics and the PID control algorithm model are constructed together to form the preset algorithm model in the industrial all-in-one machine.

5. The force position monitoring and analysis system for a press machine according to claim 4, characterized in that: The process of inversely calculating the friction coefficient and the damping coefficient by combining the theoretical formula is as follows: According to Newton's second law, the net force on the punch is equal to the product of mass and acceleration; In the actual case of friction and damping, the net force is equal to the applied external force minus the friction and damping forces; Based on the actual situation, the friction force is related to displacement and velocity, which can be expressed as: ； The damping force is related to the speed and damping coefficient, and the model is expressed as: ； Different stamping condition settings: Changing the punching speed: by controlling the drive system of the press; Set different stamping speeds to conduct stamping tests; Changing the punch load: changing the punch load by replacing the punch material with different thickness or hardness; Under each stamping condition, a force sensor and a displacement sensor are used to record the data series of the force change over time and the data series of the displacement change over time of the punch during the stamping process; According to the displacement data sequence, the velocity and acceleration data sequence are calculated by numerical difference method; According to the above theory and collected data, for each time point, the force balance equation is listed: ； Among them, t i is a time point in the time series; According to actual physical conditions and experience, the friction function is and the damping force function the specific form of Assume the friction function is: ; in, is the friction coefficient to be determined; Assume the damping force function is: ; in, is the damping coefficient to be determined; Substituting the set function into the force balance equation, a set of equations about friction coefficient related parameters and damping coefficient related parameters are obtained; Using the least square method, the system of equations is solved to obtain the values ​​of the friction coefficient related parameters and the damping coefficient related parameters; The friction coefficient related parameters and damping coefficient related parameters obtained are the specific parameters of the friction coefficient and damping coefficient obtained by reverse deduction in the assumed function form, thereby determining the friction force function and the damping force function and completing the construction of the force-displacement-time relationship mathematical model.

6. The force position monitoring and analysis system for a press machine according to claim 5, characterized in that: By analyzing the force and displacement data during the stamping process of the press and combining it with the time parameters, the process of calculating the current working state of the press is: From the correct data obtained after preprocessing, extract the data sequences related to force, displacement and corresponding timestamps respectively; the punching speed is calculated by the first-order derivative of displacement data with respect to time; in the case of discrete data, the speed is calculated by the differential method; for the punching speed vi at a certain time ti, it is calculated according to the formula vi≈(xi-xi-1) / (ti-ti-1), where i represents the i-th data point in the data sequence; install multiple force and displacement sensors at different positions of the punch on the press and at the die support points; The force data collected by each sensor is classified and sorted according to its installation position; the force distribution model of the press is constructed based on the position information of the force and displacement sensors and the collected force data; the press is discretized into multiple units using the idea of ​​finite element analysis, and each unit corresponds to the monitoring area of ​​one or more sensors; Calculate the force magnitude and direction of each unit to obtain the force distribution data; The calculated punching speed and force distribution data are integrated, including: drawing a punching speed-time curve with time as the horizontal axis and the punching speed as the vertical axis; For the force distribution, draw a two-dimensional force distribution cloud diagram of the press; thereby determining the current working status of the press, including the punching speed and force distribution.

7. The force position monitoring and analysis system for a press machine according to claim 6, characterized in that: According to the current working state of the press obtained through analysis and combined with the target parameters of the stamping process, the industrial integrated machine calculates the optimal action parameters of the press through the algorithm as follows: The industrial integrated machine first reads the target parameters of the stamping process from its internal storage or external input interface; obtains the current stamping pressure, current stamping depth and current stamping speed from the current working state of the press calculated based on the preset algorithm model, and compares the current stamping pressure with the preset stamping pressure; if the current stamping pressure is less than the preset stamping pressure, the industrial integrated machine calculates the pressure value to be increased and the corresponding adjustment strategy according to the preset algorithm model; Compare the current punching depth with the target punching depth; if the current punching depth does not reach the target punching depth, use the force-displacement-time relationship model to analyze the displacement trend and speed change of the punch; and calculate the punch stroke speed and duration that need to be adjusted based on the integral link in the PID control algorithm and the cumulative effect of the depth deviation; The current stamping speed is compared with the expected speed range; if the current speed exceeds the range, the differential link of the PID control algorithm is used to calculate the braking or acceleration control amount to be applied based on the speed change rate; Analyze the difference between the current force distribution and the ideal force state. If there is an unbalanced force, the industrial integrated machine will calculate the punch posture or pressure distribution strategy that needs to be adjusted based on the force distribution data and the mechanical structure model of the press. After comprehensive analysis and calculation of the punching pressure, punching depth, punching speed and force distribution, the industrial all-in-one machine determines a comprehensive set of optimal action parameters; the optimal action parameters include the precise stroke position adjustment of the punch, the target movement speed of the punch, the adjustment value of each pressure output point of the press, and the duration or pause time of the punching action.

8. The force position monitoring and analysis system for a press machine according to claim 7, characterized in that: The function module uses intuitive graphics to display the changes in stamping process parameters as follows: Force and displacement data processing: The data acquisition module continuously collects the force and displacement data during the stamping process of the press, records them as force and position data, and transmits them to the industrial integrated machine in the control unit; after receiving the force and position data, the control unit samples and organizes the force and position data at preset time intervals; Force and time data processing: For force / time curves, force data are also recorded at set time intervals and associated with corresponding timestamps; Torque and related data processing: In a press system with torque monitoring, the data acquisition module collects torque data and associates it with time or angle data as needed; In the display interface of the industrial integrated machine, a drawing area is opened to display different curves; set the coordinate axis. For the force / displacement curve, set the displacement as the horizontal axis and the force as the vertical axis; the force / time curve uses time as the horizontal axis and force as the vertical axis; the torque / time curve uses time as the horizontal axis and torque as the vertical axis; the torque / angle curve uses angle as the horizontal axis and torque as the vertical axis; set the scale range of the coordinate axis according to the working parameter range of the press and historical data statistics; When the stamping process starts, the starting point of the curve is first drawn. In the force / displacement curve, a point is drawn at the corresponding coordinate axis position according to the force and displacement data collected at the initial moment. For the force / time curve, the stamping start moment is taken as the time zero point, and the corresponding force value point is drawn. As the stamping process progresses, new data points are continuously acquired at set time intervals and plotted on the curve; a new set of force and displacement data is acquired every 10 milliseconds, and a new point is drawn in the drawing area of ​​the force / displacement curve according to the coordinate position of the new data, and it is connected with the previous point to form a continuous curve; for the force / time curve, new force value points are continuously drawn extending to the right on the time axis to intuitively show the trend of force changes over time; Similarly, the torque / time curve and torque / angle curve are also drawn and updated in real time according to the rhythm of data acquisition; In the torque / time curve, the torque change curve is drawn as time increases; in the torque / angle curve, the torque corresponding to the angle change is drawn according to the angle change, and then the drawn curve is displayed in real time on the display screen of the industrial all-in-one machine.

9. The force position monitoring and analysis system for a press machine according to claim 8, characterized in that: The calibration process of the calibration unit for the force sensor is as follows: Use a standard dynamometer to perform zero calibration and read the output value of the force sensor when the press is at rest and without load; If the output value is not zero, record the offset value through the calibration software in the industrial integrated machine, and set the corresponding calibration parameters to correct the zero position output of the force sensor to zero; Apply different known force values ​​to the standard force source in turn; at each calibration point, record the actual force value Fs of the standard force source and the output value Fo of the force sensor; The calibration coefficient of the force sensor is calculated by the least square method or linear regression algorithm; the relationship between the output of the force sensor and the actual force value is assumed to be Fo=kFs+b, where k is the sensitivity coefficient and b is the offset, the values ​​of k and b are solved and updated to the calibration parameters of the force sensor, thereby completing the accurate calibration of the force sensor within the entire measuring range; The calibration process of the calibration unit for the displacement sensor is as follows: A laser interferometer is used as a standard displacement measuring device to perform zero-position calibration, including: when the slider or measuring part of the press is in the initial position, read the output value of the displacement sensor; if the value is not zero, set the corresponding zero-position compensation value in the calibration software of the control unit to make the zero-position output of the displacement sensor match the actual zero displacement state; when performing range calibration: use a standard displacement measuring device to move the relevant components of the press according to the set displacement interval, including: move the slider every 10 mm from the initial position to the maximum displacement position; at each displacement point, record the actual displacement value Ds of the standard displacement measuring device and the output value Do of the displacement sensor; also use the least squares method to determine the calibration function relationship between the output value of the displacement sensor and the actual displacement value, the calculation formula is Do=mDs+n, where m is the proportionality coefficient and n is the offset, solve the values ​​of m and n and update them to the calibration parameters of the displacement sensor to complete the calibration of the displacement sensor.

10. A force position monitoring and analysis system for a press machine according to claim 9, characterized in that: Based on the torque measurement involved in the press, the process of torque calibration by the calibration unit is as follows: Using as a standard torque source, zero-position and full-scale calibration is performed, including: firstly, zero-position calibration is performed, when the torque sensor is not subjected to any torque, its output is adjusted to zero; then, the full-scale torque value of the torque sensor is applied to the standard torque source, the standard torque value Ts and the output value To of the torque sensor are recorded, and the full-scale calibration coefficient is calculated; then, multi-point calibration is performed, including: selecting multiple calibration points between zero position and full-scale, i.e., 25%, 50%, and 75% of the scale points, respectively applying corresponding standard torques and recording data, and determining the calibration curve and parameters of the torque sensor through data fitting, and the calculation formula is To=pTs+q; wherein, p is the sensitivity coefficient, q is the offset, and the calibration parameters are updated to complete the calibration; Based on the angle measurement involved in the press, the calibration unit calibrates the angle in the following process: use an encoder or an angle measuring instrument as a standard angle measuring device to perform zero position calibration, including: when the rotating part of the press is in the initial angle position, adjust the output of the angle sensor to zero; then calibrate the angle range, including: gradually rotate the part of the press corresponding to the angle, from the initial angle to the maximum angle range, and record the actual angle value As of the standard angle measuring device and the output value Ao of the angle sensor every 10°; determine the calibration relationship of the angle sensor through data processing, and the calculation formula is Ao=rAs+s; where r is the proportional coefficient and s is the offset, update the calibration parameters, and realize the calibration of the angle sensor.

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