Intelligent Monitoring and Warning Method for Loading and Unloading Safety Distance in Precision Shearing of Automotive Sheets

Abstract

The present invention relates to the field of the operation of the precision shearing manipulator for automotive panels, and discloses an intelligent monitoring and early warning method for the loading and unloading safety distance for precision shearing of automotive panels, which includes the following steps: collecting the motion parameters of the robotic arm through a high-precision spatial coordinate system, and performing a collision risk prediction modeling based on the motion parameters of the robotic arm. Combining with the constructed model, when the predicted spacing approaches the threshold, a hierarchical early warning mechanism is triggered, and the running speed and path offset of the manipulator during the precision shearing of the panel are dynamically adjusted. The present invention realizes the collaborative optimization of safety protection and production efficiency during the loading and unloading process of precision shearing of automotive panels, and provides a reliable safety guarantee for the intelligent precision shearing production line of automotive panels.

Description

Technical Field

[0001] The present invention relates to the field of automotive sheet metal precision shearing manipulator operations, and particularly to an intelligent monitoring and early warning method for the loading and unloading safety distance for automotive sheet metal precision shearing. Background Art

[0002] Precision shearing of automotive sheets is a key link in body manufacturing, requiring high-precision cutting to ensure subsequent assembly quality. During the high-speed loading and unloading process of the robotic arm, the working space is dense, and collisions are likely to occur during the coordinated operation of multiple robotic arms. The traditional fixed safety distance cannot adapt to dynamic speed changes and sudden obstacles (such as sheet displacement and equipment vibration). Intelligent monitoring can sense the environment in real time and dynamically adjust the robotic arm to achieve safe coordinated operation. At the same time, an overly conservative safety distance will reduce the operating speed of the robotic arm, while an overly aggressive strategy may lead to collisions. The intelligent system optimizes through data-driven methods to achieve the optimal balance between safety and efficiency.

[0003] An intelligent monitoring and early warning method for the loading and unloading safety distance for automotive sheet metal precision shearing is proposed. The advantages are that it can improve safety, reduce collision accidents, and protect personnel safety; secondly, it can improve production efficiency, reduce operating costs, and extend the service life of equipment, etc. Implementing intelligent monitoring and early warning of the loading and unloading safety distance in the automotive sheet metal precision shearing link is not only an inevitable choice for technological upgrading, but also a strategic measure for enterprises to achieve triple optimization of safety, efficiency, and cost. Its core value lies in transforming the traditional "passive protection" into "active prevention" through data-driven dynamic decision-making, setting a model for the coordinated development of safety and effectiveness in intelligent manufacturing. On the contrary, ignoring this technology will lead enterprises into a vicious cycle of frequent safety accidents, low efficiency, and declining competitiveness. Summary of the Invention

[0004] The present invention overcomes the deficiencies of the prior art and provides an intelligent monitoring and early warning method for the loading and unloading safety distance for automotive sheet metal precision shearing.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The first aspect of the present invention provides an intelligent monitoring and early warning method for the loading and unloading safety distance for automotive sheet metal precision shearing, including the following steps:

[0007] Build a high-precision spatial coordinate system, and collect the motion parameters of the robotic arm for sheet metal precision shearing in the high-precision spatial coordinate system, and at the same time locate the position of the sheet.

[0008] In the high-precision spatial coordinate system, combine the Monte Carlo modeling and simulation algorithm to conduct a modeling evaluation of the robotic arm collision risk prediction, and obtain the Monte Carlo collision risk prediction model.

[0009] According to the Monte Carlo collision risk prediction model, a hierarchical early warning mechanism is set up, and based on the hierarchical early warning mechanism, the running speed and path offset of the target robotic arm during the fine shearing of the board are dynamically adjusted.

[0010] Furthermore, in a preferred embodiment of the present invention, the high-precision spatial coordinate system is built, and the robotic arm motion parameters for fine shearing of the board are collected in the high-precision spatial coordinate system, and at the same time, the position of the board is located. Specifically:

[0011] The robotic arm used for fine shearing of the automotive board is calibrated as the target robotic arm, the automotive board is calibrated as the target automotive board, and at the same time, the area where the target robotic arm operates is calibrated as the target operation area;

[0012] A lidar is installed in the target operation area. Based on the lidar, real-time laser scanning is performed on the target robotic arm and the target automotive board, and a three-dimensional space coordinate system is preset. The scanning data obtained by the laser scanning is imported into the three-dimensional space coordinate system to construct a three-dimensional laser scanning model of the target robotic arm and the target automotive board, which is calibrated as the robotic arm model and the automotive board model;

[0013] In the three-dimensional space coordinate system, a checkerboard calibration board and a calibration algorithm are introduced to align the model coordinates of the robotic arm model and the automotive board model. At the same time, Kalman filtering is performed on the robotic arm model and the automotive board model in the three-dimensional space coordinate system to obtain a high-precision spatial coordinate system;

[0014] The target robotic arm is controlled to run for a trial, and during the trial run of the target robotic arm, joint encoders are installed on the target robotic arm to collect robotic arm motion parameters. Among them, the robotic arm motion parameters include the joint angles and motion speeds of the target robotic arm;

[0015] The robotic arm motion parameters are imported into the robotic arm model of the high-precision spatial coordinate system to construct a high-precision robotic arm model, and the coordinates of the high-precision robotic arm model and the automotive board model are located in the high-precision spatial coordinate system.

[0016] Furthermore, in a preferred embodiment of the present invention, in the high-precision spatial coordinate system, the Monte Carlo collision risk prediction modeling and evaluation are carried out in combination with the Monte Carlo modeling and simulation algorithm to obtain the Monte Carlo collision risk prediction model. Specifically:

[0017] A prediction time period for the robotic arm motion trajectory is preset. In the high-precision spatial coordinate system, a cubic polynomial model is introduced, and the robotic arm motion parameters are imported into the cubic polynomial model. Based on the polynomial interpolation method, the motion trajectory of the high-precision robotic arm model after the robotic arm motion trajectory prediction time period is predicted;

[0018] Combine the motion trajectory of the high-precision robotic arm model after the motion trajectory prediction period, perform spatio-temporal envelope expansion on the high-precision robotic arm model, and divide the spatio-temporal envelope of the high-precision robotic arm model into different OBBs;

[0019] Determine whether different OBBs intersect. If there is an intersection of OBBs, divide the intersection area of the OBBs into a geometric intersection area;

[0020] Among them, the OBB is a hierarchical bounding box, which is used as a geometric model to enclose the high-precision robotic arm model after spatio-temporal envelope expansion;

[0021] In the geometric intersection area in the high-precision space coordinate system, calculate the dynamic distance between different high-precision robotic arm models in real time, and combine the robotic arm motion parameters of the high-precision robotic arm model to perform Monte Carlo modeling and simulation to construct a Monte Carlo collision risk prediction model;

[0022] Among them, the Monte Carlo collision risk prediction model is used to predict and calculate the intersection probability corresponding to different dynamic distances between high-precision robotic arm models in the geometric intersection area.

[0023] Further, in a preferred embodiment of the present invention, according to the Monte Carlo collision risk prediction model, a hierarchical warning mechanism is set, and based on the hierarchical warning mechanism, the running speed and path offset of the target robotic arm during the fine shearing of the plate are dynamically adjusted. Specifically:

[0024] Based on the Monte Carlo collision risk prediction model, calculate the intersection probability corresponding to different dynamic distances between high-precision robotic arm models in the geometric intersection area, that is, calculate the collision probability between target robotic arms during the fine shearing of the target automotive sheet at different dynamic distances in the target operation area;

[0025] Preset a dangerous collision probability, and based on the dangerous collision probability, inversely deduce the dangerous dynamic distance and safety distance of the target robotic arm;

[0026] Based on the dangerous dynamic distance and safety distance of the target robotic arm, set a hierarchical warning mechanism in the high-precision space coordinate system, where the hierarchical warning mechanism includes a dangerous warning state, a state to be analyzed, and a safe state;

[0027] Based on the hierarchical warning mechanism, dynamically adjust the running speed and path offset of the target robotic arm during the fine shearing of the plate.

[0028] Further, in a preferred embodiment of the present invention, the dynamically adjusting the running speed and path offset of the target robotic arm during the fine shearing of the plate based on the hierarchical warning mechanism is specifically as follows:

[0029] Introduce the PLC control algorithm into the high-precision spatial coordinate system, and combine it with the coordinates of the high-precision robotic arm model and the automotive sheet metal model to connect the target robotic arm, so as to control the operation of the target robotic arm through the high-precision coordinate system;

[0030] When the safety state is output within the hierarchical early warning mechanism, that is, the dynamic distance between the target robotic arms is greater than the safety distance, then control the target robotic arms to continue the fine shearing process of the target automotive sheet metal in the target operation area;

[0031] When the pending analysis state is output within the hierarchical early warning mechanism, then in the high-precision coordinate space system, preset the fine shearing process limit speed of the target robotic arms, and through the PLC control algorithm, limit the maximum speed of the fine shearing process of all target robotic arms to be equal to the fine shearing process limit speed of the target robotic arms;

[0032] Introduce the APF algorithm into the high-precision spatial coordinate system, and combine it with the coordinates of the high-precision robotic arm model and the automotive sheet metal model to construct the gravitational field and repulsive field of the high-precision robotic arm model and the automotive sheet metal model;

[0033] According to the safety distance of the target robotic arms, update the gravitational function and repulsive function of the gravitational field and repulsive field of the high-precision robotic arm model and the automotive sheet metal model, and control the dynamic distance of the target robotic arms during the fine shearing process to be no greater than the safety distance;

[0034] When the dangerous early warning state is output within the hierarchical early warning mechanism, then perform local path replanning on the target robotic arms.

[0035] Furthermore, in a preferred embodiment of the present invention, when the dangerous early warning state is output within the hierarchical early warning mechanism, then perform local path replanning on the target robotic arms, specifically:

[0036] In the high-precision spatial coordinate system, when the dangerous early warning state is output within the hierarchical early warning mechanism, then determine in the high-precision spatial coordinate system that local path replanning is required;

[0037] In the high-precision spatial coordinate system, classify the high-precision robotic arm model based on the participation degree of the high-precision robotic arm model during the fine shearing process to obtain the main high-precision robotic arm model and the secondary high-precision robotic arm model;

[0038] Based on the APF algorithm, calculate the repulsive direction and gravitational direction between the main high-precision robotic arm model and the secondary high-precision robotic arm model, and based on the repulsive direction and gravitational direction, construct a temporary operation path that ensures the dynamic distance between the main high-precision robotic arm model and the secondary high-precision robotic arm model is no greater than the safety distance, and label it as a type of temporary operation path;

[0039] Calculate the deviation between the temporary running path and the original running path of the main high-precision robotic arm model and the secondary high-precision robotic arm model, which is defined as the first type of deviation. If the first type of deviation is not greater than the preset value, update the local path of the target robotic arm based on the first type of temporary path;

[0040] If the first type of deviation is greater than the preset value, directly stop all target robotic arms from performing precision shearing on the target automotive sheet.

[0041] The second aspect of the present invention also provides an intelligent monitoring and early warning system for the loading and unloading safety distance for automotive sheet precision shearing. The monitoring and early warning system includes a memory and a processor. The memory stores a monitoring and early warning method. When the monitoring and early warning method is executed by the processor, the following steps are implemented:

[0042] Build a high-precision space coordinate system, and collect the robotic arm motion parameters for sheet precision shearing in the high-precision space coordinate system, and at the same time locate the position of the sheet;

[0043] In the high-precision space coordinate system, combine the Monte Carlo modeling and simulation algorithm to conduct a predictive modeling evaluation of the robotic arm collision risk and obtain a Monte Carlo collision risk prediction model;

[0044] According to the Monte Carlo collision risk prediction model, set a hierarchical early warning mechanism, and based on the hierarchical early warning mechanism, dynamically adjust the running speed and path offset of the target robotic arm during sheet precision shearing.

[0045] The present invention solves the technical defects existing in the background art. The present invention has the following beneficial effects: Through the high-precision space coordinate system, collect the robotic arm motion parameters, and conduct a predictive modeling of the collision risk based on the robotic arm motion parameters. Combining the constructed model, when the predicted distance approaches the threshold, trigger the hierarchical early warning mechanism, and dynamically adjust the running speed and path offset of the robotic arm during sheet precision shearing. The present invention realizes the collaborative optimization of safety protection and production efficiency during the loading and unloading process of automotive sheet precision shearing, and provides a reliable safety guarantee for the intelligent precision shearing production line of automotive sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0047] Figure 1 Shows a flowchart of an intelligent monitoring and early warning method for the loading and unloading safety distance for automotive sheet precision shearing;

[0048] Figure 2 The flowchart of the method for dynamically adjusting the running speed and path offset of the target robotic arm during the fine shearing of the plate is shown;

[0049] Figure 3 The program view of the loading and unloading safety distance intelligent monitoring and warning system for the fine shearing of automotive plates is shown. Specific implementation manners

[0050] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments may be combined with each other.

[0051] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0052] Figure 1 The flowchart of the method for intelligent monitoring and warning of the loading and unloading safety distance for the fine shearing of automotive plates is shown, including the following steps:

[0053] S102: Build a high-precision spatial coordinate system, and collect the robotic arm motion parameters for the fine shearing of the plate in the high-precision spatial coordinate system, and at the same time locate the position of the plate;

[0054] S104: In the high-precision spatial coordinate system, combine the Monte Carlo modeling and simulation algorithm to perform the robotic arm collision risk prediction modeling and evaluation, and obtain the Monte Carlo collision risk prediction model;

[0055] S106: According to the Monte Carlo collision risk prediction model, set a hierarchical warning mechanism, and based on the hierarchical warning mechanism, dynamically adjust the running speed and path offset of the target robotic arm during the fine shearing of the plate.

[0056] Furthermore, in a preferred embodiment of the present invention, the building of the high-precision spatial coordinate system, and collecting the robotic arm motion parameters for the fine shearing of the plate in the high-precision spatial coordinate system, and at the same time locating the position of the plate are specifically as follows:

[0057] Calibrate the robotic arm for fine shearing of automotive plates as the target robotic arm, and calibrate the automotive plate as the target automotive plate, and at the same time calibrate the area where the target robotic arm operates as the target operation area;

[0058] Install a lidar in the target operation area. Based on the lidar, perform real-time laser scanning on the target robotic arm and the target automotive sheet metal. Preset a three-dimensional space coordinate system, import the scan data obtained by the laser scanning into the three-dimensional space coordinate system, and construct a three-dimensional laser scan model of the target robotic arm and the target automotive sheet metal, which is calibrated as the robotic arm model and the automotive sheet metal model;

[0059] In the three-dimensional space coordinate system, introduce a checkerboard calibration plate and a calibration algorithm to align the model coordinates of the robotic arm model and the automotive sheet metal model. At the same time, perform Kalman filtering on the robotic arm model and the automotive sheet metal model in the three-dimensional space coordinate system to obtain a high-precision space coordinate system;

[0060] Control the target robotic arm to run a trial operation, and install joint encoders on the target robotic arm during the trial operation of the target robotic arm to collect the robotic arm motion parameters. Among them, the robotic arm motion parameters include the joint angles and motion speeds of the target robotic arm;

[0061] Import the robotic arm motion parameters into the robotic arm model of the high-precision space coordinate system to construct a high-precision robotic arm model, and locate the coordinates of the high-precision robotic arm model and the automotive sheet metal model in the high-precision space coordinate system.

[0062] It should be noted that during the process of the robotic arm performing precise shearing on the automotive sheet metal, it is necessary to judge whether the robotic arm will collide and overlap. First, determine the target operation area, and perform three-dimensional modeling on the robotic arm and the sheet metal in the target operation area through a laser device. The purpose is to simulate the precise shearing process of the robotic arm through three-dimensional simulation, and there will be no equipment damage and other situations caused during real analysis. Introduce a checkerboard calibration plate and a calibration algorithm to align the model coordinates of the robotic arm model and the automotive sheet metal model. The purpose is to ensure that the relative positions of the robotic arm model and the automotive sheet metal model in the three-dimensional coordinate system are equal to the relative positions in reality. At the same time, the purpose of performing Kalman filtering on the model is to eliminate the occlusion error during the modeling process. Since the target robotic arm itself has operating parameters, the trial operation is used to collect the motion parameters of the robotic arm and import them into the high-precision space coordinate system to realize the setting of the motion parameters of the robotic arm model and ensure that the operating state of the robotic arm model in the coordinate system is equal to the actual state.

[0063] Furthermore, in a preferred embodiment of the present invention, in the high-precision space coordinate system, combine the Monte Carlo modeling and simulation algorithm to perform robotic arm collision risk prediction modeling and evaluation to obtain a Monte Carlo collision risk prediction model, specifically:

[0064] Preset the prediction time period of the robotic arm motion trajectory. In a high-precision spatial coordinate system, introduce a cubic polynomial model, import the robotic arm motion parameters into the cubic polynomial model, and based on the polynomial interpolation method, predict the motion trajectory of the high-precision robotic arm model after the robotic arm motion trajectory prediction time period;

[0065] Combine the motion trajectory of the high-precision robotic arm model after the robotic arm motion trajectory prediction time period, perform spatio-temporal envelope expansion on the high-precision robotic arm model, and divide the spatio-temporal envelope of the high-precision robotic arm model into different OBBs;

[0066] Judge whether different OBBs intersect. If there is an intersection of OBBs, divide the OBB intersection area into a geometric intersection area;

[0067] Among them, the OBB is a hierarchical bounding box, which is used as a geometric model to enclose the high-precision robotic arm model after spatio-temporal envelope expansion;

[0068] In the geometric intersection area in the high-precision spatial coordinate system, calculate the dynamic distance between different high-precision robotic arm models in real time, and combine the robotic arm motion parameters of the high-precision robotic arm model to perform Monte Carlo modeling and simulation to construct a Monte Carlo collision risk prediction model;

[0069] Among them, the Monte Carlo collision risk prediction model is to predict and calculate the intersection probability corresponding to different high-precision robotic arm models at different dynamic distances in the geometric intersection area.

[0070] It should be noted that the preset prediction time period of the robotic arm motion trajectory is used to judge the motion state of the robotic arm after a period of time and provide conditional data. First, it is necessary to predict the future trajectory of the robotic arm. Based on the joint angles and accelerations of the robotic arm, the polynomial interpolation method is used to predict the motion trajectory of the robotic arm in a future period of time, that is, within the prediction time period of the robotic arm motion trajectory. This can be achieved using a cubic polynomial model. The spatio-temporal envelope of the high-precision robotic arm model is extended. The spatio-temporal envelope simplifies the robotic arm into a geometric model, making it more simplified and efficient in the analysis process. The spatio-temporal envelope of the high-precision robotic arm model is divided into different OBBs for the purpose of calculating the overlap between the OBBs. If there is an overlap, it is judged that the robotic arm has a geometric intersection. The OBB is a hierarchical bounding box, which is a geometric model used to enclose the geometric model of the high-precision robotic arm model after spatio-temporal envelope expansion. It is a geometric model for collision detection and spatial calculation. Its core idea is to use a rectangular bounding box aligned with the actual direction of the object to tightly wrap the target object (such as a robotic arm, workpiece, etc.), so as to quickly judge whether a collision may occur between objects. Applied in this application, the direction of the OBB is consistent with the direction of the robotic arm and runs synchronously. By judging the overlap of the OBBs, it is possible to judge whether the robotic arms intersect. To obtain the geometric intersection area, it is necessary to calculate the dynamic distance between different robotic arms, because robotic arms that are relatively close are prone to collisions due to movement in the geometric intersection area. The geometric intersection area is an area where different robotic arms may intersect during movement. For example, in a space, the large arms of the robotic arms may intersect during movement, resulting in a collision. Then the area where collisions may occur on the large arms of different robotic arms is the geometric intersection area. Perform Monte Carlo probability collision assessment modeling, that is, randomly perturb the pose of the robotic arm and recalculate the spatio-temporal envelope to realize the judgment of the probability of geometric intersection of the robotic arm at different dynamic distances, that is, to realize the probability of collision of the robotic arm at different dynamic distances, providing conditions for the subsequent construction of a hierarchical early warning mechanism based on the dynamic distance.

[0071] The Monte Carlo method is a statistical simulation technique based on random sampling. By generating a large number of random samples and calculating their statistical results, it is used to estimate the behavior of complex systems. In the prediction of robotic arm collisions, this method can be used to simulate the uncertainties in robotic arm motion, such as sensor errors, position deviations of robotic arm joints, external disturbances, etc., so as to evaluate the probability of collision. Before performing Monte Carlo modeling and simulation, it is necessary to calculate the dynamic distance between different high-precision robotic arm models in real time and combine the robotic arm motion parameters of the high-precision robotic arm model, so as to realize the generation of Monte Carlo samples, that is, to perform multiple collision probability simulations, the construction of probability distribution models, and collision predictions. The modeling process can be achieved by directly importing the dynamic distance between different high-precision robotic arm models and the corresponding robotic arm motion parameters into the software with the Monte Carlo algorithm.

[0072] Figure 2 The method flowchart for dynamically adjusting the running speed and path offset of the target robotic arm during the fine shearing of the plate is shown, including the following steps:

[0073] S202: According to the Monte Carlo collision risk prediction model, set a hierarchical warning mechanism, and based on the hierarchical warning mechanism, dynamically adjust the running speed and path offset of the target robotic arm during the fine shearing of the plate;

[0074] S204: Based on the hierarchical warning mechanism, dynamically adjust the running speed and path offset of the target robotic arm during the fine shearing of the plate;

[0075] S206: When a danger warning state is output within the hierarchical warning mechanism, perform local path replanning on the target robotic arm.

[0076] Further, in a preferred embodiment of the present invention, the step of setting a hierarchical warning mechanism according to the Monte Carlo collision risk prediction model and dynamically adjusting the running speed and path offset of the target robotic arm during the fine shearing of the plate based on the hierarchical warning mechanism is specifically as follows:

[0077] Based on the Monte Carlo collision risk prediction model, calculate the intersection probability corresponding to different dynamic distances between high-precision robotic arm models in the geometric intersection area, that is, calculate the collision probability between target robotic arms during the fine shearing of the target automotive sheet in the target operation area at different dynamic distances;

[0078] Preset a dangerous collision probability, and based on the dangerous collision probability, inversely deduce the dangerous dynamic distance and safety distance of the target robotic arm;

[0079] Based on the dangerous dynamic distance and safety distance of the target robotic arm, set a hierarchical warning mechanism in the high-precision space coordinate system, where the hierarchical warning mechanism includes a danger warning state, a state to be analyzed, and a safety state;

[0080] Based on the hierarchical warning mechanism, dynamically adjust the running speed and path offset of the target robotic arm during the fine shearing of the plate.

[0081] It should be noted that, first, based on the Monte Carlo collision risk prediction model, the intersection probabilities corresponding to different dynamic distances between high-precision robotic arm models are predicted, and a hierarchical warning mechanism is set up to ensure that the robotic arm performs corresponding processing according to the hierarchical warning mechanism, ensuring safety during the precise shearing process of automotive panels. First, determine the dangerous collision probability. Since the Monte Carlo collision risk prediction model calculates the collision probability based on the dynamic distance, the dangerous dynamic distance and the safe distance can be inversely deduced. If the dynamic distance is less than the dangerous dynamic distance, it proves that the target robotic arm is about to collide. If it is between the dangerous dynamic distance and the safe distance, there will be no collision temporarily. If it is greater than the safe distance, it proves that there will be no collision.

[0082] Furthermore, in a preferred embodiment of the present invention, based on the hierarchical warning mechanism, the running speed and path offset of the target robotic arm during the panel precise shearing process are dynamically adjusted. Specifically:

[0083] Introduce the PLC control algorithm in the high-precision space coordinate system, and combine the coordinates of the high-precision robotic arm model and the automotive panel model to connect the target robotic arm, so that the target robotic arm is controlled to run through the high-precision coordinate system;

[0084] When the hierarchical warning mechanism outputs a safe state, that is, the dynamic distance between the target robotic arms is greater than the safe distance, control the target robotic arm to continue the precise shearing process of the target automotive panel in the target operation area;

[0085] When the hierarchical warning mechanism outputs a state to be analyzed, in the high-precision coordinate space system, preset the limited speed of the target robotic arm for precise shearing process, and through the PLC control algorithm, limit the maximum speed of all target robotic arms for precise shearing process to be equal to the limited speed of the target robotic arm for precise shearing process;

[0086] Introduce the APF algorithm in the high-precision space coordinate system, and combine the coordinates of the high-precision robotic arm model and the automotive panel model to construct the gravitational field and repulsive field of the high-precision robotic arm model and the automotive panel model;

[0087] According to the safe distance of the target robotic arm, update the gravitational function and repulsive function of the gravitational field and repulsive field of the high-precision robotic arm model and the automotive panel model, and control the dynamic distance of the target robotic arm during the precise shearing process not to be greater than the safe distance;

[0088] When the hierarchical warning mechanism outputs a dangerous warning state, perform local path replanning on the target robotic arm.

[0089] It should be noted that the PLC algorithm is used to adjust the movement speed of the robotic arm and the path offset. Through the PLC algorithm, the parameters adjusted in the high-precision coordinate space system are applied to the actual situation. Based on the hierarchical warning mechanism, if the output is in a safe state, there will be no collision between the robotic arms, and the robotic arm will continue to be controlled to perform the precise shearing of the automotive panel according to the original parameters. If the output is in a state to be analyzed, parameter adjustment of the robotic arm is required, that is, controlling the movement speed and path offset of the robotic arm. First, the speed of the robotic arm is controlled by the PLC, that is, deceleration processing is achieved. For example, the maximum speed of the robotic arm is reduced to 70% of the original speed, etc., to slow down the reduction of the dynamic distance between the robotic arms. Then, the APF algorithm is introduced to achieve path offset adjustment. Among them, the path offset adjustment is to control the path of the robotic arm to deviate slightly to ensure that there is no collision between the robotic arms. The adjustment needs to be slight, and the offset amount must be small, otherwise the precise shearing of the panel will be inaccurate. The APF algorithm is a method to achieve path offset through an artificial potential field. Through the gravitational field and repulsive field of the high-precision robotic arm model and the automotive panel model, the principle of path offset is as follows: when moving at high speed, the intensity of the repulsive field is increased to avoid path deviation caused by inertia; when moving at low speed, the weight of the repulsive force is reduced to shorten the path length and achieve path offset. The update of the gravitational function and the repulsive function is as follows: when increasing the intensity of the repulsive field, through the update function method, the path smoothing constraint term is superimposed to ensure that the trajectory planning meets the preset state.

[0090] Furthermore, in a preferred embodiment of the present invention, when a danger warning state is output within the hierarchical warning mechanism, local path replanning processing is performed on the target robotic arm, specifically:

[0091] In the high-precision space coordinate system, when a danger warning state is output within the hierarchical warning mechanism, it is determined in the high-precision space coordinate system that local path replanning is required;

[0092] In the high-precision space coordinate system, based on the participation degree of the high-precision robotic arm model in the process of precise shearing of the panel, the high-precision robotic arm model is classified to obtain the main high-precision robotic arm model and the secondary high-precision robotic arm model;

[0093] Based on the APF algorithm, calculate the repulsive force direction and gravitational force direction between the main high-precision robotic arm model and the secondary high-precision robotic arm model, and based on the repulsive force direction and gravitational force direction, construct a temporary operation path that ensures the dynamic distance between the main high-precision robotic arm model and the secondary high-precision robotic arm model is not greater than the safe distance, and label it as a type of temporary operation path;

[0094] Calculate the deviation amount between the temporary operation path of the main high-precision robotic arm model and the secondary high-precision robotic arm model and the original operation path, and define it as a type of deviation amount. If the type of deviation amount is not greater than the preset value, perform local path update on the target robotic arm based on the type of temporary path;

[0095] If a certain type of deviation amount is greater than a preset value, directly stop all target robotic arms from performing precision shearing on the target automotive sheet.

[0096] It should be noted that when the output is in a dangerous warning state, it is determined in the high-precision space coordinate system that local path replanning is required, that is, increasing the path offset to ensure that the robotic arm does not collide. First, the robotic arms need to be classified because there are robotic arms that perform the main work during the working process of the robotic arm, that is, the robotic arms that perform most of the work, and there are also robotic arms that perform small engraving. According to the classification of the robotic arms, the main high-precision robotic arm model and the secondary high-precision robotic arm model are obtained. Similarly, the gravitational and repulsive forces of the robotic arms are analyzed. The direction of the repulsive force is from the obstacle to the robotic arm, and the direction of the resultant force guides the robotic arm away from the dangerous area. The obstacle refers to another robotic arm. Local path replanning is performed according to the direction of the repulsive force and the direction of the gravitational force to generate a temporary operation path. This temporary operation path is one section of the main path. This section will cause the robotic arm to collide, so this temporary path replaces the original path, that is, the local path is updated. During the local path update process, the deviation amount between this path and the original path needs to be considered. If the deviation amount is too large, it cannot be used, which will cause a decrease in the accuracy of sheet precision shearing. If the deviation amount is too large, directly stop the sheet precision shearing process. Among them, local path replanning can be processed through B-spline curve interpolation. According to the direction of the repulsive force and the direction of the gravitational force, the path is finely adjusted, and the adjusted path points are smoothed. The control points are dynamically adjusted according to the direction of the repulsive force to ensure that the path is smooth until the robotic arm does not collide when running on the adjusted path. The formula is:

[0097]

[0098] Among them, P(u) is the temporary path point, is the p-th B-spline basis function. By obtaining multiple temporary path points, a type of temporary path can be generated.

[0099] As Figure 3 shown, in the second aspect of the present invention, an intelligent monitoring and warning system for the loading and unloading safety distance for automotive sheet precision shearing is also provided. The monitoring and warning system includes a memory 31 and a processor 32. The memory 31 stores a monitoring and warning method. When the monitoring and warning method is executed by the processor 32, the following steps are implemented:

[0100] Build a high-precision space coordinate system, and collect the motion parameters of the robotic arm for sheet precision shearing in the high-precision space coordinate system, and at the same time locate the position of the sheet;

[0101] In the high-precision space coordinate system, combine the Monte Carlo modeling and simulation algorithm to perform mechanical arm collision risk prediction modeling and evaluation to obtain a Monte Carlo collision risk prediction model;

[0102] According to the Monte Carlo collision risk prediction model, a hierarchical early warning mechanism is set, and based on the hierarchical early warning mechanism, the running speed and path offset of the target robotic arm during the fine shearing of the plate are dynamically adjusted.

[0103] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An intelligent monitoring and warning method for the safety distance of loading and unloading in the precision shearing of automotive sheets, characterized in that, The following steps are involved: Build a high-precision spatial coordinate system, collect the motion parameters of the robot arm used for plate precision shearing in the high-precision spatial coordinate system, and locate the plate position at the same time; In a high-precision spatial coordinate system, the Monte Carlo modeling and simulation algorithm is combined to carry out the robot arm collision risk prediction modeling and evaluation, and the Monte Carlo collision risk prediction model is obtained, which is as follows: Preset the robot arm motion trajectory prediction time period, introduce the cubic polynomial model, import the robot arm motion parameters into the cubic polynomial model, and predict the motion trajectory of the high-precision robot arm model after the robot arm motion trajectory prediction time period based on the polynomial interpolation method; Combined with the motion trajectory of the high-precision robot arm model after the robot arm motion trajectory prediction time period, the spatiotemporal envelope of the high-precision robot arm model is expanded, and the spatiotemporal envelope of the high-precision robot arm model is divided into different OBBs; Determine whether different OBBs intersect. If so, divide the OBB intersection area into geometric intersection areas; In the geometric intersection area, the dynamic distance between different high-precision robotic arm models is calculated in real time, and Monte Carlo modeling simulation is performed in combination with the robotic arm motion parameters to build a Monte Carlo collision risk prediction model, which is used to estimate and calculate the corresponding intersection probability between high-precision robotic arm models at different dynamic distances in the geometric intersection area; According to the Monte Carlo collision risk prediction model, a graded warning mechanism is set up, and based on the graded warning mechanism, the running speed and path offset of the target robot arm during the plate fine shearing process are dynamically adjusted.

2. The intelligent monitoring and early warning method for the loading and unloading safety distance facing the precision shearing of automotive sheets according to claim 1, characterized in that, The high-precision spatial coordinate system is constructed, and the motion parameters of the robot arm used for plate precision shearing are collected in the high-precision spatial coordinate system, and the position of the plate is located at the same time, specifically: The robot arm used for fine shearing of automobile plates is calibrated as the target robot arm, the automobile plate is calibrated as the target automobile plate, and the area where the target robot arm operates is calibrated as the target operation area; A laser radar is installed in the target operation area, and based on the laser radar, a target robotic arm and a target automobile plate are subjected to real-time laser scanning, and a three-dimensional spatial coordinate system is preset, and the scanning data obtained by the laser scanning is imported into the three-dimensional spatial coordinate system, and a three-dimensional laser scanning model of the target robotic arm and the target automobile plate is constructed, and calibrated as a robotic arm model and an automobile plate model; In the three-dimensional space coordinate system, a checkerboard calibration plate and a calibration algorithm are introduced to align the model coordinates of the robot arm model and the car plate model. At the same time, Kalman filtering is performed on the robot arm model and the car plate model in the three-dimensional space coordinate system to obtain a high-precision space coordinate system. Controlling the test run of the target robotic arm, and installing a joint encoder on the target robotic arm during the test run of the target robotic arm to collect the robotic arm motion parameters, wherein the robotic arm motion parameters include the joint angle and motion speed of the target robotic arm; The robot arm motion parameters are imported into the robot arm model of the high-precision spatial coordinate system to construct a high-precision robot arm model, and the high-precision robot arm model coordinates and the automobile plate model coordinates are located in the high-precision spatial coordinate system.

3. The intelligent monitoring and warning method for the loading and unloading safety distance facing the fine shearing of automotive sheets according to claim 1, wherein, According to the Monte Carlo collision risk prediction model, a hierarchical early warning mechanism is set up, and based on the hierarchical early warning mechanism, the running speed and path offset of the target robotic arm during the fine shearing of the board are dynamically adjusted. Specifically: Based on the Monte Carlo collision risk prediction model, calculate the intersection probability corresponding to different dynamic distances between high-precision robotic arm models in the geometric intersection area, that is, calculate the collision probability during the fine shearing of the target automotive sheet by the target robotic arms at different dynamic distances in the target operation area; Preset a dangerous collision probability, and based on the dangerous collision probability, inversely deduce the dangerous dynamic distance and safety distance of the target robotic arm; Based on the dangerous dynamic distance and safety distance of the target robotic arm, set up a hierarchical early warning mechanism in the high-precision space coordinate system, where the hierarchical early warning mechanism includes a dangerous early warning state, a state to be analyzed, and a safe state; Based on the hierarchical early warning mechanism, dynamically adjust the running speed and path offset of the target robotic arm during the fine shearing of the board.

4. The intelligent monitoring and warning method for the loading and unloading safety distance facing the fine shearing of automotive sheets according to claim 3, wherein The dynamic adjustment of the running speed and path offset of the target robotic arm during the fine shearing of the board based on the hierarchical early warning mechanism is specifically as follows: Introduce a PLC control algorithm in the high-precision space coordinate system, and combine the coordinates of the high-precision robotic arm model and the automotive sheet model to connect the target robotic arm, so as to control the operation of the target robotic arm through the high-precision coordinate system; When the safe state is output within the hierarchical early warning mechanism, that is, the dynamic distance between the target robotic arms is greater than the safety distance, control the target robotic arm to continue the fine shearing process of the target automotive sheet in the target operation area; When the state to be analyzed is output within the hierarchical early warning mechanism, in the high-precision coordinate space system, preset the limited speed of the target robotic arm for fine shearing processing, and through the PLC control algorithm, limit the maximum speed of all target robotic arms for fine shearing processing to be equal to the limited speed of the target robotic arm for fine shearing processing; Introduce an APF algorithm in the high-precision space coordinate system, and combine the coordinates of the high-precision robotic arm model and the automotive sheet model to construct the gravitational field and repulsive field of the high-precision robotic arm model and the automotive sheet model; According to the safety distance of the target robotic arm, update the gravitational function and repulsive function of the gravitational field and repulsive field of the high-precision robotic arm model and the automotive sheet model, and control the dynamic distance of the target robotic arm during the fine shearing process to be greater than the dangerous dynamic distance; When the dangerous early warning state is output within the hierarchical early warning mechanism, perform local path replanning on the target robotic arm.

5. The intelligent monitoring and early warning method for the loading and unloading safety distance facing the precision shearing of automotive sheets according to claim 4, characterized in that, When the dangerous early warning state is output within the hierarchical early warning mechanism, the specific method for performing local path replanning on the target robotic arm is as follows: In the high-precision space coordinate system, when the dangerous early warning state is output within the hierarchical early warning mechanism, it is determined in the high-precision space coordinate system that local path replanning is required; In the high-precision space coordinate system, based on the participation degree of the high-precision robotic arm model during the fine shearing process, classify the high-precision robotic arm model to obtain the main high-precision robotic arm model and the secondary high-precision robotic arm model; Based on the APF algorithm, calculate the repulsive force direction and the attractive force direction between the main high-precision robotic arm model and the secondary high-precision robotic arm model, and based on the repulsive force direction and the attractive force direction, construct a temporary operating path that ensures the dynamic distance between the main high-precision robotic arm model and the secondary high-precision robotic arm model is greater than the dangerous dynamic distance, which is calibrated as a type-I temporary operating path; Calculate the deviation amount between the temporary operating path of the main high-precision robotic arm model and the secondary high-precision robotic arm model and the original operating path, which is defined as a type-I deviation amount. If the type-I deviation amount is not greater than the preset value, perform local path update on the target robotic arm based on the type-I temporary path; If the type-I deviation amount is greater than the preset value, directly stop all target robotic arms from performing precision shearing on the target automotive sheet.

6. The intelligent monitoring and warning system for the loading and unloading safety distance of automotive sheet metal fine shearing is characterized in that The monitoring and warning system includes a memory and a processor. The memory stores a monitoring and warning method program. When the monitoring and warning method program is executed by the processor, the steps of the monitoring and warning method described in any one of claims 1-5 are implemented.

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