Counterweight type robot polishing automatic clamping system
The intelligent workpiece adaptive automatic clamping module solves the problem of manual intervention required by existing clamping systems, and achieves accurate and stable clamping of different workpieces, improving production efficiency and automation level. It is particularly suitable for precision machining and mold manufacturing.
Patent Information
- Application Number
- CN202511770136.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-27
- Publication Date
- 2026-01-02
AI Technical Summary
Existing automatic clamping systems require manual intervention or adjustment when dealing with workpieces of different shapes, sizes, and surface features, failing to achieve full automation and intelligence, resulting in low operating efficiency and workpiece damage.
The system employs an intelligent workpiece adaptive automatic clamping module, which includes a vision recognition unit, an actuator, a force feedback unit, and a control system. Through multi-angle image acquisition, real-time force monitoring, and PID adjustment, it plans the optimal clamping path to achieve automated and intelligent clamping.
It enables precise clamping of diverse workpieces, avoids workpiece damage, improves production efficiency and clamping stability, has self-learning capabilities, and is suitable for precision machining.
Smart Images
Figure CN121245897A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of robot automation, and more specifically, to a counterweight-based automatic clamping system for robot grinding. Background Technology
[0002] In traditional industrial production, especially in areas involving workpiece grinding, cleaning, or precision machining, manual operation requires a significant amount of time and manpower. Furthermore, problems such as unstable clamping, excessive or insufficient clamping force can easily occur during workpiece clamping, leading to workpiece damage or low operational efficiency. With the development of automation technology, the application of robots in automated clamping is gradually being promoted, especially counterweight robots, which offer better stability and precision in grinding processes.
[0003] Existing grinding robot clamping systems mostly employ static or simple mechanical clamping methods, lacking flexible intelligent adaptability and real-time feedback control. Furthermore, existing automated clamping systems typically require manual intervention or adjustment when dealing with workpieces of different shapes, sizes, and surface features, failing to achieve full automation and intelligence. With the continuous improvement of industrial demands, existing systems still have shortcomings in workpiece recognition, clamping path planning, and clamping stability monitoring, necessitating a more intelligent and efficient automated grinding clamping system. Summary of the Invention
[0004] The purpose of this invention is to provide a counterweight-based automatic clamping system for robot grinding, which solves the problem that existing automatic clamping systems usually require manual intervention or adjustment when dealing with workpieces of different shapes, sizes and surface features, and cannot achieve the requirements of full automation and intelligence.
[0005] This invention achieves the above objective through the following technical solution: a counterweight-based robot grinding automatic clamping system, comprising: Intelligent workpiece adaptive automatic clamping module and control system; The intelligent workpiece adaptive automatic clamping module includes a vision recognition unit, an actuator, clamping components, and a force feedback unit. The visual recognition unit is used to acquire image information of the workpiece to be polished and analyze and determine the shape, size and surface feature parameters of the workpiece; The control system plans the clamping path and clamping point distribution scheme based on the shape, size and surface feature parameters of the workpiece, combined with the preset grinding process requirements of the counterweight robot grinding system, and controls the actuator to drive the clamping components to move according to the planned scheme to clamp the workpiece. The force feedback unit is used to collect clamping force data in real time during the clamping process of the clamping assembly, and transmit the data to the control system. The control system is also used to compare the clamping force data with the preset safe clamping force threshold range, and control the actuator to adjust the clamping driving force according to the comparison result so that the clamping force is stable within the threshold range, while locking the position of the clamping component to complete the automatic clamping of the workpiece.
[0006] Furthermore, the visual recognition unit includes at least two sets of image acquisition devices and image processing modules; The image acquisition device is used to acquire multi-angle images of the workpiece from different spatial directions to obtain a two-dimensional image dataset of the workpiece; The image processing module is used to perform noise reduction, edge enhancement and contour extraction on the two-dimensional image dataset, separate the workpiece area and the background area to obtain an independent image of the workpiece, and call the preset workpiece feature recognition model to perform feature matching and calculation on the independent image, output the size parameters and surface feature parameters of the workpiece, and generate a three-dimensional contour mapping map of the workpiece.
[0007] Furthermore, it also includes coordinate transformation units: The coordinate transformation unit is pre-set with a transformation matrix between the camera coordinate system and the workpiece coordinate system, and the transformation matrix is obtained through camera calibration; The coordinate transformation unit, based on the transformation matrix, converts the coordinate data in the camera coordinate system obtained when the image acquisition device acquires images into coordinate data in the workpiece coordinate system, so as to generate a three-dimensional contour mapping map of the workpiece.
[0008] Furthermore, the control system includes a process parameter extraction module, an effective area screening module, and a clamping planning module; The process parameter extraction module is used to extract the preset grinding process parameters of the counterweight robot grinding system. The preset grinding process parameters include at least the grinding area, grinding force, grinding path and workpiece stress limit value. The effective area filtering module is used to filter out the grinding area, surface protrusions and hole positions of the workpiece based on the three-dimensional contour mapping and size parameters of the workpiece, and filter out the effective area on the workpiece that can be used for clamping. The clamping planning module is used to calculate the coordinate positions of at least three clamping points based on the effective area using a clamping point optimization algorithm, and to plan the movement path of the clamping component according to the coordinate positions of the clamping points and the initial position of the clamping component. The movement path avoids the vulnerable parts of the workpiece and the movement trajectory is a smooth curve.
[0009] Furthermore, the clamping point optimization algorithm in the clamping planning module aims to achieve the highest clamping stability and the best uniformity of workpiece force. The clamping point optimization algorithm has a preset objective function, which is related to the clamping force of the clamping point, the average clamping force, the center of gravity of the workpiece, and the distance parameter of the support surface formed by the clamping point. The objective function also has weight coefficients corresponding to different parameters.
[0010] Furthermore, the force feedback unit includes a force detection element and a data transmission module; The force detection element is integrated into the clamping contact surface of the clamping assembly to collect clamping force data, and the measurement accuracy of the force detection element is not less than 0.1N, and the sampling frequency is not less than 10Hz. The data transmission module uses a wireless communication protocol to transmit the clamping force data collected by the force detection element to the control system in real time.
[0011] Furthermore, the control system also includes a threshold calculation module: The threshold calculation module is used to determine the preset safe clamping force threshold range based on the material and thickness of the workpiece. The threshold calculation module has a preset calculation formula for the upper and lower limits of the safe clamping force. The calculation formula for the upper limit of the safe clamping force is related to the compressive strength of the workpiece material, the thickness of the workpiece clamping part and the contact area between the clamping component and the workpiece, and the formula includes a safety margin coefficient. The formula for calculating the lower limit of the safety clamping force is related to the upper limit of the safety clamping force, and the formula includes a minimum stable clamping coefficient. For curved workpieces, the threshold calculation module also has a preset contact area correction formula, which is used to correct the contact area between the clamping component and the curved workpiece.
[0012] Furthermore, the control system includes a PID control module: The PID control module is used to achieve precise control of the clamping force during the process of increasing or decreasing the clamping driving force of the control actuator. The PID adjustment module has a preset target value for PID adjustment, and the target value is the middle value of the preset safety clamping force threshold range; The PID adjustment module is also used to calculate the deviation between the current clamping force data and the target value, and calculate the driving force adjustment of the actuator based on the deviation value using the PID algorithm. At the same time, the adjustment is sent to the drive motor of the actuator to control the speed and torque changes of the motor. The PID control module also has a preset adaptive correction formula for the PID parameters, which is used to adaptively correct the PID parameters based on the deviation value or the rate of change of the deviation value.
[0013] Furthermore, it also includes a clamping stability detection module: The clamping stability detection module is used to detect the clamping stability after the workpiece is automatically clamped. The clamping stability detection module is used to control the grinding head of the counterweight robot to briefly contact the non-grinding area of the workpiece with a preset test force to simulate slight force during the grinding process. The clamping stability detection module is also used to collect clamping force change data and workpiece displacement data during the test process through the force feedback unit, and to determine whether the clamping is stable based on the preset clamping stability evaluation index calculation formula. If the clamping is determined to be unstable, the clamping stability detection module is also used to control the force feedback unit and the actuator to re-execute the force adjustment step, and to fine-tune the clamping force a second time until the clamping stability detection is passed.
[0014] Furthermore, it also includes a database and parameter matching module: The database is used to store the clamping parameters of the workpiece and to establish a mapping relationship between workpiece type and clamping parameters. The parameter matching module is used to calculate the matching degree between the subsequent workpiece and the workpiece type stored in the database when loading the subsequent workpiece. If the matching degree reaches the preset threshold, it is determined to be a workpiece of the same type, and the system automatically calls the clamping parameters of the corresponding workpiece type in the database to perform the clamping operation. If the matching degree does not reach the preset threshold, it is determined to be a new type of workpiece. The system recalculates the parameters and clamping control, and adds the new workpiece type-clamping parameter mapping relationship to the database. The parameter matching module has a preset formula for calculating the matching degree of workpiece type. The calculation formula is associated with the feature parameters of the workpiece, the feature parameter weights, and the workpiece feature parameters stored in the database.
[0015] The beneficial effects of this invention are as follows: 1. Through multi-angle image acquisition and processing by the vision recognition unit, the system can accurately obtain the shape, size and surface features of the workpiece, automatically analyze and generate a three-dimensional contour mapping map, providing a basis for subsequent clamping path planning and clamping point optimization. It has strong adaptability and can cope with diverse workpieces. 2. The system monitors the clamping force in real time during the clamping process through the force feedback unit and compares it with the preset safe clamping force threshold to ensure that the clamping force is always within the safe range, preventing damage to the workpiece due to excessive or insufficient clamping. Through the PID adjustment module, the clamping force is precisely controlled to achieve stable and reliable automatic clamping. 3. Based on the workpiece's 3D contour map and effective area screening, the system can plan the optimal clamping path and avoid vulnerable parts, while ensuring the uniformity of the workpiece's force and the stability of the clamping. The clamping point optimization algorithm maximizes the clamping stability and avoids workpiece damage caused by uneven clamping. 4. The system has self-learning capabilities. Through the database and parameter matching module, it can automatically match workpiece types and parameters, avoiding manual intervention and greatly improving the system's automation level and production efficiency. 5. This system can handle workpieces of various shapes and sizes, and is particularly suitable for production scenarios with high precision grinding and process requirements. It has broad application prospects, especially in the fields of precision machining, mold manufacturing, and electronic component processing, where it has significant advantages. Attached Figure Description
[0016] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a flowchart illustrating the overall workflow of the present invention. Figure 2 This is a flowchart of the clamping point optimization algorithm of the present invention; Figure 3 This is a flowchart of the clamping stability testing process of the present invention. Detailed Implementation
[0017] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.
[0018] Example 1: Please see Figure 1-3 This invention provides a technical solution: a counterweight-based robot grinding automatic clamping system, the system comprising: Intelligent workpiece adaptive automatic clamping module and control system; The intelligent workpiece adaptive automatic clamping module includes a vision recognition unit, an actuator, clamping components, and a force feedback unit; The visual recognition unit is used to acquire image information of the workpiece to be polished and analyze and determine the shape, size and surface feature parameters of the workpiece; Based on the shape, size and surface feature parameters of the workpiece, combined with the preset grinding process requirements of the counterweight robot grinding system, the control system plans the clamping path and clamping point distribution scheme, and controls the actuator to drive the clamping components to move according to the planned scheme to clamp the workpiece. The force feedback unit is used to collect clamping force data in real time during the clamping process of the clamping assembly, and transmit the data to the control system. The control system is also used to compare the clamping force data with the preset safe clamping force threshold range, and control the actuator to adjust the clamping driving force according to the comparison result, so that the clamping force is stable within the threshold range, while locking the position of the clamping component to complete the automatic clamping of the workpiece.
[0019] The specific operating method is as follows: S1. Obtain the original information of the workpiece to be polished, and use the vision recognition unit in the intelligent workpiece adaptive automatic clamping module to collect and analyze images of the workpiece to determine the shape, size and surface feature parameters of the workpiece. Among them, the original information of the workpiece to be polished refers to the various basic information contained in the workpiece itself before polishing, which is the basic data source for a series of subsequent operations; the intelligent workpiece adaptive automatic clamping module is a module with intelligent functions that can automatically adjust the clamping method according to the characteristics of different workpieces, and is the core system part to realize automatic clamping; the vision recognition unit is the component in this module used to collect and analyze images. It acquires workpiece images through devices such as cameras and uses image processing and analysis algorithms to determine the shape, size and surface feature parameters of the workpiece; among the shape, size and surface feature parameters, shape refers to the geometric shape of the workpiece; size covers the specific measurement data such as the length, width, height and diameter of the workpiece; surface feature parameters include indicators reflecting the surface condition of the workpiece, such as surface roughness and texture. S2. Based on the shape, size and surface feature parameters of the workpiece, and combined with the preset grinding process requirements of the counterweight robot grinding system, plan the clamping path and clamping point distribution scheme. Among them, the preset grinding process requirements are various standards for the grinding process that are pre-set for the counterweight robot grinding system, such as grinding accuracy, grinding speed, and grinding depth. They are an important basis for planning the clamping path and clamping point distribution scheme. The clamping path is the movement trajectory of the clamping component from its initial position to the preset clamping point on the workpiece. A reasonable clamping path can improve clamping efficiency and accuracy. The clamping point distribution scheme is the selection of clamping positions on the workpiece and their distribution method based on the shape, size, and surface feature parameters of the workpiece, combined with the preset grinding process requirements. A good clamping point distribution can ensure that the workpiece is stable and subjected to uniform force during the grinding process. S3. Start the actuator in the intelligent workpiece adaptive automatic clamping module, and drive the clamping component to move towards the preset clamping point of the workpiece according to the planned clamping path and clamping point distribution scheme. The actuator is the part responsible for executing the actual actions in the intelligent workpiece adaptive automatic clamping module. It can drive the clamping components to move according to the planned clamping path and clamping point distribution scheme to realize the clamping operation. The clamping components are the specific parts driven by the actuator to clamp the workpiece, which usually include jaws, clamps, etc. They achieve the clamping function by contacting the workpiece and applying a certain force. The preset clamping points are the positions on the workpiece that are suitable for clamping, which are predetermined according to the characteristics of the workpiece and the grinding process requirements. S4. During the contact process between the clamping component and the workpiece, the force feedback unit in the intelligent workpiece adaptive automatic clamping module collects clamping force data in real time and compares the clamping force data with the preset safe clamping force threshold range. Among them, the force feedback unit is a component in the intelligent workpiece adaptive automatic clamping module used to collect clamping force data in real time during the clamping process. It senses the magnitude of the force between the clamping component and the workpiece through sensors and other devices. The clamping force data is numerical information collected by the force feedback unit that reflects the magnitude of the force applied by the clamping component to the workpiece. It is the key data for judging whether the clamping state is appropriate. The preset safe clamping force threshold range is a reasonable range of clamping force that is set in advance. Within this range, the workpiece can be firmly clamped without being damaged or deformed due to excessive clamping force. S5. If the clamping force data is lower than the preset lower limit of the safe clamping force threshold, control the actuator to increase the clamping driving force until the clamping force reaches the threshold range; if the clamping force data is higher than the preset upper limit of the safe clamping force threshold, control the actuator to reduce the clamping driving force to avoid excessive deformation of the workpiece. Among them, the lower limit of the preset safety clamping force threshold is the minimum value in the preset safety clamping force threshold range. When the clamping force data is lower than this value, it indicates that the clamping force is insufficient and the workpiece may not be firmly clamped. The clamping driving force is the force applied to the workpiece by the actuator driving the clamping components. The clamping force can be adjusted by controlling the magnitude of the clamping driving force. The upper limit of the preset safety clamping force threshold is the maximum value in the preset safety clamping force threshold range. When the clamping force data is higher than this value, it indicates that the clamping force is too large and the workpiece may deform due to excessive force. S6. When the clamping force is stable within the preset safe clamping force threshold range, lock the position of the clamping component to complete the automatic clamping of the workpiece, providing a stable clamping foundation for the counterweight robot's grinding operation. The locking of the clamping component position involves fixing the clamping component in its current position through a mechanical structure or control system after the clamping force has stabilized within the preset safe clamping force threshold range. This prevents the clamping component from moving during subsequent grinding operations and ensures that the workpiece is always in a stable clamping state.
[0020] It should be noted that during use, the visual recognition unit acquires the workpiece's shape, size, and surface feature parameters to accurately understand the workpiece's characteristics, providing a reliable basis for subsequent operations. Combined with preset grinding process requirements, the clamping path and clamping point distribution scheme are planned to ensure that the clamping method matches the grinding needs, improving grinding quality and efficiency. The force feedback unit collects clamping force data in real time and compares it with preset thresholds, dynamically adjusting the clamping driving force to avoid workpiece damage or clamping instability due to improper clamping force. When the clamping force is stable within a suitable range, the position of the clamping components is locked, providing a stable foundation for the robot's grinding operation and ensuring the safety and stability of the grinding process. The entire design achieves full automation and intelligence from workpiece recognition and clamping planning to force control, improving the accuracy and reliability of grinding operations.
[0021] In one embodiment, the original information of the workpiece to be polished is obtained, and the workpiece is image-acquired and analyzed by the vision recognition unit in the intelligent workpiece adaptive automatic clamping module to determine the shape, size, and surface feature parameters of the workpiece, including: The visual recognition unit includes at least two sets of industrial cameras and an image preprocessing module. The two sets of industrial cameras acquire images from the horizontal and vertical directions of the workpiece from multiple angles to obtain a two-dimensional image dataset of the workpiece. The image preprocessing module performs noise reduction, edge enhancement, and contour extraction on the two-dimensional image dataset to remove environmental noise and highlight the contour features of the workpiece. Based on the contour extraction results, an image segmentation algorithm is used to separate the workpiece area from the background area to obtain an independent image of the workpiece. The system calls a preset workpiece feature recognition model to perform feature matching and calculation on independent workpiece images, outputs the workpiece's length, width, height and other dimensional parameters, as well as the workpiece's surface feature parameters such as protrusions, depressions and holes, and generates a three-dimensional contour mapping of the workpiece. The coordinate transformation formula for the 3D contour mapping is as follows: Let the coordinates of a point in the camera coordinate system be... Transform to workpiece coordinate system The formula is:
[0022] In the formula, This is the transformation matrix from the camera coordinate system to the workpiece coordinate system, obtained through camera calibration.
[0023] This design uses two sets of industrial cameras to acquire workpiece images from different directions and multiple angles. The image preprocessing module reduces noise, enhances edges, and extracts contours. Then, an image segmentation algorithm separates the workpiece region. Finally, a feature recognition model outputs parameters and generates a 3D contour map. Multi-angle acquisition can comprehensively obtain workpiece information and avoid missing key features; image preprocessing can remove interference, highlight contours, and improve the accuracy of subsequent processing; separating the workpiece region facilitates precise analysis; and outputting detailed parameters and a 3D map can provide accurate basis for subsequent clamping path planning and clamping point distribution, making clamping more closely fit the characteristics of the workpiece and ensuring the stability and quality of grinding operations.
[0024] In one embodiment, based on the shape, size, and surface feature parameters of the workpiece, and combined with the preset grinding process requirements of the counterweight robot grinding system, a clamping path and clamping point distribution scheme are planned, including: Extract the preset grinding process parameters of the counterweight robot grinding system. The parameters include grinding area, grinding force, grinding path and the stress limit value of the workpiece during the grinding process. Based on the workpiece's three-dimensional contour mapping and dimensional parameters, the grinding area, surface protrusions, and hole locations of the workpiece are excluded, and the effective areas on the workpiece that can be used for clamping are selected. Based on the effective area, a clamping point optimization algorithm is adopted to calculate the coordinate positions of at least 3 clamping points with the goal of "highest clamping stability and best workpiece force uniformity" to ensure that the support surface formed by the clamping points coincides with the projection of the workpiece's center of gravity. The objective function for clamp point optimization is: , In the formula, , These are the weighting coefficients. For the first The clamping force at each clamping point To achieve average clamping force, Center of gravity of the workpiece Support surface formed at the clamping point distance, This represents the number of gripping points; Based on the coordinates of the clamping point and the initial position of the clamping component, plan the movement path of the clamping component. The path should avoid the vulnerable parts of the workpiece, and the movement trajectory should be a smooth curve to avoid collision between the clamping component and the workpiece during the clamping process.
[0025] This design extracts preset grinding process parameters, selects effective clamping areas based on the workpiece's 3D model and dimensional parameters, calculates the coordinates of the clamping points using an optimization algorithm, plans the movement path of the clamping components, and ensures that the clamping meets grinding requirements by extracting process parameters; selecting effective areas avoids clamping in unsuitable locations; the optimization algorithm aims at clamping stability and uniform force distribution on the workpiece, improving clamping reliability; and planning a smooth path that avoids vulnerable parts of the workpiece prevents collisions between the clamping components and the workpiece during clamping, ensuring a safe and efficient clamping process and providing a solid foundation for grinding operations.
[0026] In one embodiment, the force feedback unit in the intelligent workpiece adaptive automatic clamping module includes a pressure sensor and a data transmission module. The pressure sensor is integrated into the clamping contact surface of the clamping component, and the data transmission module uses a wireless communication protocol to transmit the collected clamping force data to the control system in real time. The pressure sensor has a measurement accuracy of no less than 0.1N and a sampling frequency of no less than 10Hz to ensure that it can capture subtle changes in force during the clamping process. The preset safe clamping force threshold range is determined based on the workpiece's material and thickness, and the specific calculation method is as follows: Assume the compressive strength of the workpiece material is The thickness of the workpiece clamping part is The contact area between the clamping assembly and the workpiece is The upper limit of the safety clamping force Lower limit of safe clamping force Among them, the coefficient 0.8 is the safety margin coefficient to avoid damage to the workpiece caused by the ultimate compressive strength of the material, and the coefficient 0.5 is the minimum stable clamping coefficient to ensure that the workpiece does not shift during the grinding process. For curved workpieces, the corrected formula for calculating the contact area S is:
[0027] In the formula, The nominal area of the clamping surface of the mounting assembly. The angle between the clamping surface and the normal direction of the workpiece surface.
[0028] This design integrates a pressure sensor into the clamping contact surface using the force feedback unit. Data is transmitted wirelessly, measurement accuracy and sampling frequency are set, and the safe clamping force threshold range is determined based on the workpiece material and thickness. Corrections are made for the contact area of curved workpieces. The high-precision and high-sampling-frequency pressure sensor can accurately capture changes in clamping force; wireless transmission ensures real-time data transmission; the threshold range is determined based on workpiece characteristics to avoid workpiece damage or displacement; and the correction for the contact area of curved workpieces enables more accurate calculation of the safe clamping force, ensuring that the clamping force is within a reasonable range, thus guaranteeing clamping quality and workpiece safety.
[0029] In one embodiment, during the process of controlling the actuator to increase or decrease the clamping driving force, a PID control algorithm is used to achieve precise control of the clamping force. The specific control steps include: The target value for PID control is set to the midpoint of the preset safety clamping force threshold range:
[0030] Calculate the current clamping force data With target value Deviation value:
[0031] Based on deviation value The driving force adjustment of the actuator is calculated using a PID algorithm:
[0032] in This is the proportionality coefficient. The integral coefficient is... These are the differential coefficients; The adaptive correction formula for PID parameters is:
[0033]
[0034]
[0035] In the formula, , , These are the initial parameters. , , This is a correction factor, with a value ranging from 0.1 to 0.5; Adjustment amount The signal is sent to the drive motor of the actuator, controlling the motor's speed and torque changes, thereby adjusting the clamping force of the clamping assembly until the deviation value is reached. The absolute value is less than This enables stable control of the clamping force.
[0036] This design employs a PID control algorithm to regulate the clamping force. A target value is set, the deviation is calculated, and the algorithm calculates the adjustment amount. The PID parameters are then adaptively corrected, and this adjustment is sent to the drive motor to adjust the clamping force. The PID algorithm precisely adjusts the driving force based on the deviation between the current clamping force and the target value, achieving stable control of the clamping force. The adaptive correction parameters dynamically adjust the algorithm parameters according to the magnitude of the deviation, improving the accuracy and adaptability of the regulation. By continuously adjusting until the deviation meets the requirements, the clamping force is ensured to remain within the safe clamping force threshold range, guaranteeing the stability and reliability of the clamping process and providing stable conditions for grinding operations.
[0037] In one embodiment, after the automatic clamping of the workpiece is completed, a clamping stability detection step is further included, specifically including: The grinding head of the counterweight robot is controlled to briefly contact the non-grinding area of the workpiece with a preset test force (30% of the normal grinding force) to simulate the slight force during the grinding process. The clamping force change data and workpiece displacement data are collected in real time by the force feedback unit. If the displacement data is less than 0.1mm and the clamping force change is less than 10%, the clamping is considered stable and the grinding operation can be started. The formula for calculating the clamping stability evaluation index is:
[0038] In the formula, This represents the workpiece displacement. =0.1mm is the displacement threshold. This represents the change in clamping force. When S≥0.9, the clamping is considered stable; If the displacement data is greater than or equal to 0.1 mm or the clamping force change is greater than or equal to 10%, the force feedback unit will be re-executed to fine-tune the clamping force a second time until the clamping stability test is passed.
[0039] This design allows for stability testing after clamping. The grinding head is controlled to contact the non-grinding area of the workpiece with a test force, and data on clamping force changes and workpiece displacement are collected. An evaluation index is used to determine clamping stability; if unstable, secondary adjustments are made. Simulating the force during the grinding process provides a more realistic reflection of clamping stability in actual operation. Collecting force and displacement data allows for a comprehensive evaluation of the clamping effect. The evaluation index considers both displacement and force changes, providing a quantitative judgment result. Secondary adjustments for instability further improve clamping stability, preventing workpiece movement or damage during grinding due to clamping instability, ensuring smooth grinding operations and product quality.
[0040] In one embodiment, the method is also applicable to the continuous clamping of batches of workpieces of different sizes and shapes, specifically implemented as follows: After the first workpiece is clamped, the clamping parameters of the workpiece are stored in the database to establish a mapping relationship between workpiece type and clamping parameters. When loading the same type of workpiece in the future, the system automatically calls the clamping parameters stored in the database and directly executes the clamping path planning and force adjustment steps without having to re-perform visual recognition and parameter calculation. If the subsequent loaded workpiece is of a new type, the system will recalculate the parameters and control the clamping according to the above steps S1-S6, and add the new workpiece type-clamping parameter mapping relationship to the database to realize the self-learning and accumulation of clamping parameters. The formula for calculating the matching degree of the new workpiece type is:
[0041] In the formula, The number of feature parameters, For the first The weights of each feature parameter, For the first time of the new workpiece One feature parameter, For a certain type of workpiece in the database, the first One characteristic parameter; when When the value is ≥0.85, it is determined to be a workpiece of the same type.
[0042] This design allows the method to be applied to the continuous clamping of workpieces of different sizes and shapes in batches. After the first workpiece is clamped, the parameters are stored, and subsequent workpieces of the same type are automatically retrieved. For new types of workpieces, the parameters are recalculated and supplemented. The workpiece type is determined by a matching degree formula. Storing and retrieving clamping parameters can greatly improve clamping efficiency and reduce repetitive calculations and identification time. For new types of workpieces, the recalculation and supplementation of parameters can continuously improve the database, realizing the self-learning and accumulation of clamping parameters. The matching degree formula can accurately determine the workpiece type, ensuring that the appropriate clamping parameters are called, making the clamping process more intelligent and efficient, reducing the difficulty and cost of operation, and improving the flexibility and adaptability of the production line.
[0043] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0044] The above embodiments provide a detailed description of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.
Claims
1. A counterweight-based automatic clamping system for robotic grinding, characterized in that, include: Intelligent workpiece adaptive automatic clamping module and control system; The intelligent workpiece adaptive automatic clamping module includes a vision recognition unit, an actuator, clamping components, and a force feedback unit. The visual recognition unit is used to acquire image information of the workpiece to be polished and analyze and determine the shape, size and surface feature parameters of the workpiece; The control system plans the clamping path and clamping point distribution scheme based on the shape, size and surface feature parameters of the workpiece, combined with the preset grinding process requirements of the counterweight robot grinding system, and controls the actuator to drive the clamping components to move according to the planned scheme to clamp the workpiece. The force feedback unit is used to collect clamping force data in real time during the clamping process of the clamping assembly, and transmit the data to the control system. The control system is also used to compare the clamping force data with the preset safe clamping force threshold range, and control the actuator to adjust the clamping driving force according to the comparison result so that the clamping force is stable within the threshold range, while locking the position of the clamping component to complete the automatic clamping of the workpiece.
2. The automatic clamping system for counterweight-type robot grinding according to claim 1, characterized in that: The visual recognition unit includes at least two sets of image acquisition devices and an image processing module; The image acquisition device is used to acquire multi-angle images of the workpiece from different spatial directions to obtain a two-dimensional image dataset of the workpiece; The image processing module is used to perform noise reduction, edge enhancement and contour extraction on the two-dimensional image dataset, separate the workpiece area and the background area to obtain an independent image of the workpiece, and call the preset workpiece feature recognition model to perform feature matching and calculation on the independent image, output the size parameters and surface feature parameters of the workpiece, and generate a three-dimensional contour mapping map of the workpiece.
3. The automatic clamping system for counterweight-type robot grinding according to claim 2, characterized in that, It also includes coordinate transformation units: The coordinate transformation unit is pre-set with a transformation matrix between the camera coordinate system and the workpiece coordinate system, and the transformation matrix is obtained through camera calibration; The coordinate transformation unit, based on the transformation matrix, converts the coordinate data in the camera coordinate system obtained when the image acquisition device acquires images into coordinate data in the workpiece coordinate system, so as to generate a three-dimensional contour mapping map of the workpiece.
4. The automatic clamping system for counterweight-type robot grinding according to claim 1, characterized in that: The control system includes a process parameter extraction module, an effective area screening module, and a clamping planning module. The process parameter extraction module is used to extract the preset grinding process parameters of the counterweight robot grinding system. The preset grinding process parameters include at least the grinding area, grinding force, grinding path and workpiece stress limit value. The effective area filtering module is used to filter out the grinding area, surface protrusions and hole positions of the workpiece based on the three-dimensional contour mapping and size parameters of the workpiece, and filter out the effective area on the workpiece that can be used for clamping. The clamping planning module is used to calculate the coordinate positions of at least three clamping points based on the effective area using a clamping point optimization algorithm, and to plan the movement path of the clamping component according to the coordinate positions of the clamping points and the initial position of the clamping component. The movement path avoids the vulnerable parts of the workpiece and the movement trajectory is a smooth curve.
5. The automatic clamping system for counterweight-type robot grinding according to claim 4, characterized in that: The clamping point optimization algorithm in the clamping planning module aims to achieve the highest clamping stability and the best uniformity of workpiece force. The clamping point optimization algorithm has a preset objective function, which is related to the clamping force, average clamping force, workpiece center of gravity and distance parameters of the support surface formed by the clamping point. The objective function also has weight coefficients corresponding to different parameters.
6. The automatic clamping system for counterweight-type robot grinding according to claim 1, characterized in that: The force feedback unit includes a force detection element and a data transmission module; The force detection element is integrated into the clamping contact surface of the clamping assembly to collect clamping force data, and the measurement accuracy of the force detection element is not less than 0.1N, and the sampling frequency is not less than 10Hz. The data transmission module uses a wireless communication protocol to transmit the clamping force data collected by the force detection element to the control system in real time.
7. The automatic clamping system for counterweight-type robot grinding according to claim 1, characterized in that, The control system also includes a threshold calculation module: the threshold calculation module is used to determine a preset safe clamping force threshold range based on the material and thickness of the workpiece; The threshold calculation module has a preset calculation formula for the upper and lower limits of the safe clamping force. The calculation formula for the upper limit of the safe clamping force is related to the compressive strength of the workpiece material, the thickness of the workpiece clamping part and the contact area between the clamping component and the workpiece, and the formula includes a safety margin coefficient. The formula for calculating the lower limit of the safety clamping force is related to the upper limit of the safety clamping force, and the formula includes a minimum stable clamping coefficient. For curved workpieces, the threshold calculation module also has a preset contact area correction formula, which is used to correct the contact area between the clamping component and the curved workpiece.
8. The automatic clamping system for counterweight-type robot grinding according to claim 1, characterized in that, The control system includes a PID control module: The PID control module is used to achieve precise control of the clamping force during the process of increasing or decreasing the clamping driving force of the control actuator. The PID adjustment module has a preset target value for PID adjustment, and the target value is the middle value of the preset safety clamping force threshold range; The PID adjustment module is also used to calculate the deviation between the current clamping force data and the target value, and calculate the driving force adjustment of the actuator based on the deviation value using the PID algorithm. At the same time, the adjustment is sent to the drive motor of the actuator to control the speed and torque changes of the motor. The PID control module also has a preset adaptive correction formula for the PID parameters, which is used to adaptively correct the PID parameters based on the deviation value or the rate of change of the deviation value.
9. The automatic clamping system for counterweight-type robot grinding according to claim 1, characterized in that, It also includes a clamping stability detection module: The clamping stability detection module is used to detect the clamping stability after the workpiece is automatically clamped. The clamping stability detection module is used to control the grinding head of the counterweight robot to briefly contact the non-grinding area of the workpiece with a preset test force to simulate slight force during the grinding process. The clamping stability detection module is also used to collect clamping force change data and workpiece displacement data during the test process through the force feedback unit, and to determine whether the clamping is stable based on the preset clamping stability evaluation index calculation formula. If the clamping is determined to be unstable, the clamping stability detection module is also used to control the force feedback unit and the actuator to re-execute the force adjustment step, and to fine-tune the clamping force a second time until the clamping stability detection is passed.
10. The automatic clamping system for counterweight-type robot grinding according to claim 1, characterized in that, It also includes a database and parameter matching module: The database is used to store the clamping parameters of the workpiece and to establish a mapping relationship between workpiece type and clamping parameters. The parameter matching module is used to calculate the matching degree between the subsequent workpiece and the workpiece type stored in the database when loading the subsequent workpiece. If the matching degree reaches the preset threshold, it is determined to be a workpiece of the same type, and the system automatically calls the clamping parameters of the corresponding workpiece type in the database to perform the clamping operation. If the matching degree does not reach the preset threshold, it is determined to be a new type of workpiece. The system recalculates the parameters and clamping control, and adds the new workpiece type-clamping parameter mapping relationship to the database. The parameter matching module has a preset formula for calculating the matching degree of workpiece type. The calculation formula is associated with the feature parameters of the workpiece, the feature parameter weights, and the workpiece feature parameters stored in the database.