A polishing system and polishing method for automotive parts

Abstract

The present application relates to the technical field of polishing equipment, and particularly relates to a polishing system and polishing method for automobile parts, which obtains motion data of a polishing spindle, front profile data, rear profile data and abrasive belt running data, and corresponds the data before and after polishing to the same workpiece surface position according to accumulated track distance; determines an effective contact window according to workpiece boundary information and obtains a predicted profile, so that a target supporting profile is formed before the abrasive belt working section enters a polishing contact area on the workpiece surface; obtains unit area polishing energy according to effective polishing power, effective contact window width and feed speed, and generates a feed speed control instruction; obtains actual material removal amount according to the profile before and after polishing, corrects the target unit area polishing energy or generates a supplementary polishing instruction, reduces local under-polishing and over-polishing, and improves the consistency and processing stability of surface polishing.

Description

Technical Field

[0001] This invention relates to the field of polishing equipment technology, and in particular to a polishing system and method for automotive parts. Background Technology

[0002] After casting, forging, stamping and machining, automotive parts usually need to have their surface burrs, flash, parting lines, weld excess and machining marks polished.

[0003] As automotive parts production moves towards automation, industrial robots, in conjunction with belt sanders, are gradually being applied to the surface processing of parts such as housings, brackets, wheel hubs, and bearing seats, to complete workpiece positioning, trajectory movement, and continuous sanding operations.

[0004] Existing robotic grinding systems typically control the sanding belt to move along the workpiece surface according to a pre-taught or offline planned trajectory, and perform processing according to the set sanding belt speed, robot feed speed and grinding load. Some systems also adjust the contact state between the sanding belt and the workpiece through contour detection, force sensing or compliance control, thereby adapting to workpiece clamping deviations and surface size changes.

[0005] In actual production, the area to be polished for the same automotive part often includes flat surfaces, curved surfaces, contour transition areas, and free edges. When the robot drives the sanding belt to continuously pass through the above areas, the existing polishing system is difficult to achieve a polishing effect that matches the target removal amount at different workpiece surface positions, and the actual material removal amount after polishing is prone to differences. Summary of the Invention

[0006] The main objective of this invention is to provide a grinding system and method for automotive parts, which aims to solve the problem that the amount of material removed from different workpiece surfaces is difficult to keep consistent during the existing grinding process for automotive parts, which can easily lead to local under-grinding or over-grinding.

[0007] To achieve the above objectives, the present invention provides a grinding system for automotive parts, the system comprising: The data acquisition module is used to acquire motion data of the grinding spindle, front contour data, rear contour data and abrasive belt running data. The front contour data includes grinding front contour information and workpiece boundary information. The spatial correspondence module is used to obtain the cumulative trajectory distance based on the motion data, and to map the front contour data and the rear contour data to the workpiece surface position in the grinding contact area based on the cumulative trajectory distance. The window analysis module is used to determine the effective contact window based on the workpiece boundary information corresponding to the workpiece surface position, and to obtain the predicted contour based on the pre-grinding contour information within the effective contact window. The forming control module is used to obtain contour control instructions based on the predicted contour, so that the sanding belt working section forms the target support contour before entering the grinding contact area on the corresponding workpiece surface. The energy control module is used to obtain the effective grinding power based on the sanding belt running data, obtain the grinding energy per unit area based on the effective grinding power, the width of the effective contact window and the feed speed of the grinding spindle, and obtain the feed speed control command based on the grinding energy per unit area. The feedback correction module is used to obtain the actual material removal amount based on the pre-grinding contour information and the post-grinding contour data corresponding to the same workpiece surface position, and to correct the target unit area grinding energy or generate supplementary grinding instructions based on the actual material removal amount. The execution control module is used to execute the contour control command, the feed speed control command, and the supplementary grinding command.

[0008] Optionally, the motion data includes trajectory position and feed rate; The spatial correspondence module is used to associate each set of preceding contour data with the corresponding cumulative trajectory distance, and when the difference between the current cumulative trajectory distance and the corresponding cumulative trajectory distance reaches a preset preceding distance, the corresponding preceding contour data is mapped to the workpiece surface position in the grinding contact area.

[0009] Optionally, the space correspondence module is further configured to associate the acquired post-contour data with the pre-grinding contour information corresponding to the workpiece surface position after the workpiece surface position passes through the grinding contact area and continues to move a preset post-contour distance.

[0010] Optionally, the window analysis module is specifically used for: The grinding range in the width direction of the abrasive belt is obtained based on the workpiece boundary information, the grinding range is determined as the effective contact window, and the predicted contour is obtained based on the contour height of each detection position within the effective contact window.

[0011] Optionally, the forming control module is specifically used for: The contour height and average contour height of each detection position in the predicted contour are obtained. The target support contour is determined based on the height difference between each contour height and the average contour height, and the corresponding contour control command is obtained.

[0012] Optionally, the sanding belt operating data includes actual operating power and sanding belt linear speed; The energy control module is specifically used for: The no-load power is obtained based on the belt linear velocity, the difference between the actual working power and the no-load power is determined as the effective grinding power, and the feed speed control command is generated based on the deviation between the grinding energy per unit area and the target grinding energy per unit area.

[0013] Optionally, the feedback correction module is specifically used for: Based on the pre-grinding contour information, the pre-grinding surface normal is obtained. The positional difference between the pre-grinding surface point and the post-grinding surface point at the same workpiece surface position is projected along the pre-grinding surface normal to obtain the actual material removal amount. Based on the deviation between the actual material removal amount and the target material removal amount, the target unit area grinding energy is corrected or the supplementary grinding command is generated.

[0014] To achieve the above objectives, the present invention also provides a method for polishing automotive parts, the method comprising: Acquire motion data of the grinding spindle, front contour data, rear contour data, and abrasive belt operation data. The front contour data includes grinding front contour information and workpiece boundary information. The cumulative trajectory distance is obtained based on the motion data, and the front contour data and the rear contour data are respectively mapped to the workpiece surface position in the grinding contact area based on the cumulative trajectory distance. The effective contact window is determined based on the workpiece boundary information corresponding to the workpiece surface position, and the predicted contour is obtained based on the pre-grinding contour information within the effective contact window. Based on the predicted contour, a contour control command is obtained to enable the sanding belt working section to form a target support contour before entering the grinding contact area on the corresponding workpiece surface. The effective grinding power is obtained based on the sanding belt operation data. The grinding energy per unit area is obtained based on the effective grinding power, the width of the effective contact window, and the feed speed of the grinding spindle. The feed speed control command is obtained based on the grinding energy per unit area. The actual material removal amount is obtained based on the pre-grinding contour information and the post-grinding contour data corresponding to the same workpiece surface position. The target unit area grinding energy is corrected or a supplementary grinding command is generated based on the actual material removal amount. Execute the contour control command, the feed rate control command, and the supplementary grinding command.

[0015] Optionally, mapping the preceding contour data and the following contour data to the workpiece surface positions in the grinding contact area includes: Associate each set of preceding contour data with the corresponding cumulative trajectory distance; When the difference between the current cumulative trajectory distance and the corresponding cumulative trajectory distance reaches a preset preceding distance, the corresponding preceding contour data is mapped to the grinding contact area; After passing through the grinding contact area at the corresponding workpiece surface position and continuing to move a preset rear distance, the acquired rear contour data is associated with the pre-grinding contour information at the workpiece surface position.

[0016] Optionally, the step of adjusting the target unit area grinding energy or generating and executing supplementary grinding instructions based on the actual material removal amount includes: The surface normal before grinding is obtained based on the pre-grinding contour information; The positional difference between a point on the surface before grinding and a point on the surface after grinding at the same workpiece surface position is projected along the normal of the surface before grinding to obtain the actual amount of material removed. When the actual material removal amount is less than the target material removal amount, the grinding energy per unit area of ​​the corresponding workpiece surface position is increased and supplementary grinding is performed; when the actual material removal amount is greater than the target material removal amount, the grinding energy per unit area of ​​the subsequent corresponding workpiece surface position is reduced.

[0017] The beneficial effects that this invention can achieve are as follows: This invention acquires motion data of the grinding spindle, pre-contour data, post-contour data, and abrasive belt running data through a data acquisition module. A spatial correspondence module maps the pre- and post-grinding data to the same workpiece surface position in the grinding contact area based on the cumulative trajectory distance. A window analysis module determines the effective contact window and obtains the predicted contour based on workpiece boundary information. A forming control module generates contour control commands, ensuring the abrasive belt forms the target support contour before entering the grinding contact area on the workpiece surface. Simultaneously, an energy control module acquires the grinding energy per unit area based on the effective grinding power, effective contact window width, and grinding spindle feed speed, and generates feed speed control commands. A feedback correction module acquires the actual material removal amount based on the pre-grinding contour information and post-contour data, thereby correcting the target unit area grinding energy or generating supplementary grinding commands. This achieves continuous control of pre-grinding prediction, process adjustment, and post-grinding correction, allowing the abrasive belt to adapt to changes in workpiece boundaries and surface contours in advance, and adjusting subsequent parameters based on actual removal results. This reduces local under-grinding, over-grinding, and repeated grinding, improving the processing consistency and dimensional stability of complex surfaces and edge areas. Attached Figure Description

[0018] Figure 1 This is a structural block diagram of the system in Embodiment 1 of the present invention; Figure 2 This is a flowchart illustrating the method in Embodiment 2 of the present invention.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0022] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0024] Example 1: As attached Figure 1 As shown, this embodiment provides a grinding system for automotive parts, the system comprising: The data acquisition module is used to acquire motion data of the grinding spindle, front contour data, rear contour data and abrasive belt running data. The front contour data includes grinding front contour information and workpiece boundary information. The spatial correspondence module is used to obtain the cumulative trajectory distance based on the motion data, and to map the front contour data and the rear contour data to the workpiece surface position in the grinding contact area based on the cumulative trajectory distance. The window analysis module is used to determine the effective contact window based on the workpiece boundary information corresponding to the workpiece surface position, and to obtain the predicted contour based on the pre-grinding contour information within the effective contact window. The forming control module is used to obtain contour control instructions based on the predicted contour, so that the sanding belt working section forms the target support contour before entering the grinding contact area on the corresponding workpiece surface. The energy control module is used to obtain the effective grinding power based on the sanding belt running data, obtain the grinding energy per unit area based on the effective grinding power, the width of the effective contact window and the feed speed of the grinding spindle, and obtain the feed speed control command based on the grinding energy per unit area. The feedback correction module is used to obtain the actual material removal amount based on the pre-grinding contour information and the post-grinding contour data corresponding to the same workpiece surface position, and to correct the target unit area grinding energy or generate supplementary grinding instructions based on the actual material removal amount. The execution control module is used to execute the contour control command, the feed speed control command, and the supplementary grinding command.

[0025] In this embodiment, the motion data includes trajectory position and feed rate; The spatial correspondence module is used to associate each set of preceding contour data with the corresponding cumulative trajectory distance, and when the difference between the current cumulative trajectory distance and the corresponding cumulative trajectory distance reaches a preset preceding distance, the corresponding preceding contour data is mapped to the workpiece surface position in the grinding contact area.

[0026] In this embodiment, the space correspondence module is further configured to associate the acquired post-contour data with the pre-grinding contour information corresponding to the workpiece surface position after the workpiece surface position passes through the grinding contact area and continues to move a preset post-contour distance.

[0027] In this embodiment, the window analysis module is specifically used for: The grinding range in the width direction of the abrasive belt is obtained based on the workpiece boundary information, the grinding range is determined as the effective contact window, and the predicted contour is obtained based on the contour height of each detection position within the effective contact window.

[0028] In this embodiment, the forming control module is specifically used for: The contour height and average contour height of each detection position in the predicted contour are obtained. The target support contour is determined based on the height difference between each contour height and the average contour height, and the corresponding contour control command is obtained.

[0029] In this embodiment, the sanding belt operating data includes actual operating power and sanding belt linear speed; The energy control module is specifically used for: The no-load power is obtained based on the belt linear velocity, the difference between the actual working power and the no-load power is determined as the effective grinding power, and the feed speed control command is generated based on the deviation between the grinding energy per unit area and the target grinding energy per unit area.

[0030] In this embodiment, the feedback correction module is specifically used for: Based on the pre-grinding contour information, the pre-grinding surface normal is obtained. The positional difference between the pre-grinding surface point and the post-grinding surface point at the same workpiece surface position is projected along the pre-grinding surface normal to obtain the actual material removal amount. Based on the deviation between the actual material removal amount and the target material removal amount, the target unit area grinding energy is corrected or the supplementary grinding command is generated.

[0031] It should be noted that, in this embodiment, the polishing system includes a memory, a processor, and a data interface that is communicatively connected to the processor. The data acquisition module, space correspondence module, window analysis module, forming control module, energy control module, feedback correction module, and execution control module are stored in the memory in the form of software or firmware and are executed by the processor. Each module can be set separately or integrated into the same controller according to the data processing order.

[0032] In this embodiment, the grinding spindle is located at the end of the industrial robot, and the sanding belt is wound around the sanding belt drive assembly, forming a grinding contact area for contacting automotive parts in the working section of the sanding belt. Along the feed direction of the grinding spindle, a front contour detection device is positioned in front of the grinding contact area, and a rear contour detection device is positioned behind the grinding contact area. It should be noted that both the front and rear sides are based on the feed direction of the grinding spindle along the current grinding trajectory. The front contour detection device passes over the workpiece surface before the sanding belt working section, and the rear contour detection device acquires contour data after completing the grinding on the corresponding workpiece surface.

[0033] Specifically, the data acquisition module first acquires the motion data of the grinding spindle. The motion data includes the trajectory position of the grinding spindle on the current grinding trajectory, the actual feed speed, and the corresponding acquisition time. The data source can be the trajectory execution data output by the industrial robot controller. The data acquisition module also acquires the front contour data and the rear contour data. The front contour data is acquired by a line laser contour sensor or other detection device capable of acquiring the workpiece surface contour, and the rear contour data is acquired by a contour detection device located on the rear side of the grinding contact area.

[0034] Among them, the pre-grinding contour information is used to characterize the contour height and surface orientation of the workpiece surface before grinding; the workpiece boundary information is used to characterize the boundary position between the workpiece solid surface and the non-workpiece area; the post-grinding contour data is used to characterize the surface contour of the same workpiece surface position after grinding; the sanding belt operation data includes the actual working power of the sanding belt drive motor and the sanding belt linear speed. The actual working power is read from the sanding belt driver, and the sanding belt linear speed is obtained according to the drive motor speed and the sanding belt drive wheel size, or it can be directly detected by the speed sensor.

[0035] After obtaining the above data, the spatial correspondence module acquires the cumulative trajectory distance of the grinding spindle along the path to be ground based on the motion data. In one specific implementation, the first... The cumulative trajectory distance over one collection cycle can satisfy: ; In the formula, Indicates the first The cumulative trajectory distance corresponding to each collection cycle; This represents the cumulative trajectory distance corresponding to the previous data collection period; Indicates the first The grinding spindle feed speed for each acquisition cycle is derived from the industrial robot controller; This represents the time interval between adjacent acquisition cycles, which is derived from the sampling cycle setting of the control system.

[0036] The above expression uses cumulative trajectory distance for correspondence because the front contour detection device, the grinding contact area, and the rear contour detection device are set sequentially and at intervals along the feed direction. The same workpiece surface position will pass through the above three positions in sequence. Compared with calling contour data according to a fixed time, the cumulative trajectory distance can still maintain the correspondence between the contour data and the actual workpiece surface position when the grinding spindle accelerates, decelerates, or stops briefly.

[0037] Specifically, when the spatial correspondence module collects a set of preceding contour data, it associates and stores this set of preceding contour data with the cumulative trajectory distance during collection. Let the preset preceding distance along the grinding trajectory between the preceding contour detection position and the grinding contact area be... When the difference between the current cumulative trajectory distance and the cumulative trajectory distance corresponding to the previous set of contour data reaches... At that time, the spatial correspondence module maps the set of previous contour data to the workpiece surface position that is currently entering the grinding contact area.

[0038] Accordingly, the preset rear distance between the grinding contact area and the rear contour detection position is set as follows: The workpiece continues to move after its surface position passes the grinding contact area. At that time, the spatial correspondence module associates the rear contour data currently acquired by the rear contour detection device with the pre-grinding contour information of the workpiece surface position. The preset front distance and preset rear distance can be calibrated according to the actual installation positions between the front contour detection device, the sanding belt working section, and the rear contour detection device.

[0039] After completing the spatial correspondence of the preceding contour data, the window analysis module determines the effective contact window of the current workpiece surface position based on the workpiece boundary information. Specifically, the window analysis module divides the preceding contour data into multiple detection positions along the width direction of the abrasive belt, and determines whether each detection position is within the scope of the workpiece solid surface. The width range covered by the detection positions that are continuously within the scope of the workpiece solid surface and meet the preset boundary spacing requirements is determined as the effective contact window.

[0040] It should be noted that the effective contact window is used to limit the actual width of the sanding belt working section at the current workpiece surface position. When the sanding belt working section is located in a relatively wide planar area, the effective contact window can be close to the overall width of the sanding belt working section. When the sanding belt working section enters a narrow area or is close to the free edge of the workpiece, the effective contact window decreases accordingly with the workpiece boundary position. Based on this, the entire width of the sanding belt is avoided as the effective grinding width.

[0041] After determining the effective contact window, the window analysis module extracts the predicted surface height of each detection position from the pre-grinding contour information within the effective contact window, and forms a predicted contour according to the arrangement order in the sanding belt width direction; the predicted contour is used to represent the relative height change of the workpiece surface about to enter the grinding contact area in the sanding belt width direction.

[0042] After obtaining the predicted profile, the forming control module obtains the profile control command based on the predicted profile. In one specific implementation, the average surface height of each detection position within the effective contact window can be obtained first, and then the target support profile can be determined based on the difference between the predicted surface height of each detection position and the average surface height.

[0043] No. The target support position corresponding to each detection position can satisfy: ; In the formula, Indicates the first In the first collection cycle The target support position corresponding to each detection position; This indicates the support position of the working section of the sanding belt when it is in the reference state, which is derived from the initial system calibration. Indicates the first The predicted surface height at each detection location is derived from the window analysis module; This represents the average height of each predicted surface within the effective contact window.

[0044] By subtracting the average surface height, the overall height variation of the workpiece surface can be separated from the local contour variation in the width direction. The overall height variation of the workpiece surface can be adjusted by the industrial robot to adjust the overall position of the grinding spindle, while the local height variation within the effective contact window is adjusted by the support state of the sanding belt working section. Thus, the sanding belt working section forms the target support contour before the corresponding workpiece surface enters the grinding contact area.

[0045] In this embodiment, the target support profile is formed by an adjustable support actuator set on the back side of the sanding belt working section. The adjustable support actuator can be set with multiple independently adjustable support positions along the width direction of the sanding belt. The execution control module outputs corresponding profile control commands according to each target support position. It should be noted that the adjustable support actuator is only one way to implement the target support profile. Other actuators that can change the support shape on the back side of the sanding belt working section can also be used.

[0046] After the target support contour is formed in the working section of the sanding belt and comes into contact with the workpiece, the energy control module obtains the effective grinding power based on the sanding belt operation data. The actual working power of the sanding belt drive motor includes not only the grinding power generated by the sanding belt contacting the workpiece, but also the basic power corresponding to the sanding belt idling, bearing friction and transmission loss. Therefore, the corresponding no-load power can be obtained first based on the sanding belt linear speed, and then the no-load power can be subtracted from the actual working power.

[0047] The effective grinding power can meet the following requirements: ; In the formula, Indicates the first Effective grinding power per acquisition cycle; This indicates the actual operating power of the belt drive motor, which is derived from the belt driver. Indicates the linear velocity of the abrasive belt; This represents the no-load power of the sanding belt when it is running at the current sanding belt linear speed. It is derived from the correspondence between sanding belt linear speed and no-load power established during the equipment commissioning phase.

[0048] After obtaining the effective grinding power, the energy control module combines the width of the effective contact window and the feed speed of the grinding spindle to obtain the grinding energy per unit area: ; In the formula, This indicates the grinding energy per unit area; The width of the effective contact window is derived from the window analysis module; This indicates the actual feed rate of the grinding spindle; This indicates the effective grinding power.

[0049] Within a single acquisition cycle, the product of the effective grinding power and the acquisition cycle represents the grinding energy input from the abrasive belt to the workpiece. The product of the width of the effective contact window and the moving distance of the grinding spindle within that acquisition cycle represents the surface area of ​​the workpiece swept by the abrasive belt. Therefore, the grinding energy per unit area can characterize the grinding effect received at the current workpiece surface position.

[0050] The energy control module compares the grinding energy per unit area with the target grinding energy per unit area and obtains a feed speed control command based on the comparison result. When the grinding energy per unit area is lower than the target grinding energy per unit area, the feed speed of the grinding spindle can be reduced to prolong the time the abrasive belt acts on the unit trajectory length. When the grinding energy per unit area is higher than the target grinding energy per unit area, the feed speed of the grinding spindle can be increased to reduce the continuous action of the abrasive belt on the unit trajectory length. The target grinding energy per unit area can be obtained through trial grinding calibration based on the workpiece material, abrasive belt grit size, abrasive belt linear speed, and target material removal amount.

[0051] After grinding is completed on the workpiece surface, the feedback correction module obtains the pre-grinding contour information and post-grinding contour data of the same workpiece surface position based on the correlation results of the spatial corresponding module. For inclined or curved surfaces, in order to avoid deviation caused by directly comparing vertical heights, the actual material removal amount can be calculated along the normal of the pre-grinding surface. ; In the formula, Indicates the cumulative trajectory position First The actual amount of material removed at each detection location; This indicates the surface point before grinding at the detection location, which is derived from the preceding contour data; The points on the polished surface at the same detection location are derived from the subsequent contour data; The unit normal of the surface point before polishing is derived from the contour information before polishing; The symbol “·” represents the vector dot product.

[0052] The feedback correction module compares the actual material removal amount with the target material removal amount at the corresponding position. When the actual material removal amount is within the allowable range corresponding to the target material removal amount, the current target unit area grinding energy can be maintained. When the actual material removal amount is less than the target material removal amount, the target unit area grinding energy at the corresponding workpiece surface position can be increased, and a supplementary grinding command can be generated. When the actual material removal amount is greater than the target material removal amount, the target unit area grinding energy used at subsequent positions with the same or similar contours can be reduced.

[0053] In one specific implementation, the correction process for the grinding energy per unit area of ​​the target area can satisfy: ; In the formula, This indicates the corrected grinding energy per unit area. This indicates the grinding energy per unit area before the correction. Indicates the amount of target material removed; This indicates the actual average amount of material removed within the effective contact window. This represents the calibration coefficient between the deviation in material removal and the energy correction amount; and These represent the lower and upper limits of the allowable grinding energy per unit area, respectively. This indicates that the correction result will be limited between the lower and upper limits.

[0054] Finally, the execution control module receives and executes contour control instructions, feed speed control instructions, and supplementary grinding instructions. The contour control instructions are used to control the sanding belt working section to form the target support contour before entering the grinding contact area on the corresponding workpiece surface. The feed speed control instructions are used to adjust the feed speed of the grinding spindle along the grinding trajectory. The supplementary grinding instructions include at least the position of the workpiece surface to be supplemented and the corresponding target unit area grinding energy, and are used to control the grinding spindle to re-pass through the position where the material removal is insufficient.

[0055] It is understandable that in this embodiment, the modules form a continuous control link according to the data processing sequence. First, the data acquisition module acquires motion data, contour data before and after grinding, and abrasive belt running data. Second, the spatial correspondence module maps the data acquired at different locations to the same workpiece surface position. Then, the window analysis module and the forming control module determine the effective range of the abrasive belt and the target support contour in advance. During the grinding process, the energy control module controls the grinding energy per unit area. After grinding is completed, the feedback correction module corrects the subsequent control parameters based on the actual material removal amount.

[0056] Based on the above, this embodiment does not control the grinding process solely based on the sanding belt load or the grinding spindle position. Instead, it associates the pre-grinding contour, workpiece boundary, sanding belt running state, and post-grinding contour according to the workpiece surface position, so that the target support contour, grinding energy per unit area, and actual material removal amount form a continuous data processing relationship, thereby improving the problem of inconsistent material removal amounts at different surface positions of automotive parts.

[0057] Example 2: As attached Figure 2 As shown, this embodiment provides a method for polishing automotive parts, the method including: Acquire motion data of the grinding spindle, front contour data, rear contour data, and abrasive belt operation data. The front contour data includes grinding front contour information and workpiece boundary information. The cumulative trajectory distance is obtained based on the motion data, and the front contour data and the rear contour data are respectively mapped to the workpiece surface position in the grinding contact area based on the cumulative trajectory distance. The effective contact window is determined based on the workpiece boundary information corresponding to the workpiece surface position, and the predicted contour is obtained based on the pre-grinding contour information within the effective contact window. Based on the predicted contour, a contour control command is obtained to enable the sanding belt working section to form a target support contour before entering the grinding contact area on the corresponding workpiece surface. The effective grinding power is obtained based on the sanding belt operation data. The grinding energy per unit area is obtained based on the effective grinding power, the width of the effective contact window, and the feed speed of the grinding spindle. The feed speed control command is obtained based on the grinding energy per unit area. The actual material removal amount is obtained based on the pre-grinding contour information and the post-grinding contour data corresponding to the same workpiece surface position. The target unit area grinding energy is corrected or a supplementary grinding command is generated based on the actual material removal amount. Execute the contour control command, the feed rate control command, and the supplementary grinding command.

[0058] In this embodiment, mapping the preceding contour data and the following contour data to the workpiece surface positions in the grinding contact area includes: Associate each set of preceding contour data with the corresponding cumulative trajectory distance; When the difference between the current cumulative trajectory distance and the corresponding cumulative trajectory distance reaches a preset preceding distance, the corresponding preceding contour data is mapped to the grinding contact area; After passing through the grinding contact area at the corresponding workpiece surface position and continuing to move a preset rear distance, the acquired rear contour data is associated with the pre-grinding contour information at the workpiece surface position.

[0059] In this embodiment, the step of adjusting the target unit area grinding energy or generating and executing supplementary grinding instructions based on the actual material removal amount includes: The surface normal before grinding is obtained based on the pre-grinding contour information; The positional difference between a point on the surface before grinding and a point on the surface after grinding at the same workpiece surface position is projected along the normal of the surface before grinding to obtain the actual amount of material removed. When the actual material removal amount is less than the target material removal amount, the grinding energy per unit area of ​​the corresponding workpiece surface position is increased and supplementary grinding is performed; when the actual material removal amount is greater than the target material removal amount, the grinding energy per unit area of ​​the subsequent corresponding workpiece surface position is reduced.

[0060] It should be noted that the automotive parts polishing method provided in this embodiment is executed in the order of data acquisition, spatial correspondence, contour control, energy control and result feedback, and each step can be implemented by the automotive parts polishing system described in Embodiment 1.

[0061] Specifically, firstly, motion data such as the trajectory position and feed speed of the grinding spindle are acquired. Pre-contour data of the front side of the grinding contact area, post-contour data of the rear side, and belt running data are also acquired. Based on the motion data, the cumulative trajectory distance of the grinding spindle along the grinding path is calculated, and each set of pre-contour data is associated with the cumulative trajectory distance at the time of data acquisition. When the difference between the current cumulative trajectory distance and the cumulative trajectory distance at the time of acquisition reaches a preset pre-contour distance, the corresponding pre-contour data is mapped to the current grinding contact area. The effective contact window of the belt in the width direction is determined based on the workpiece boundary information. A predicted contour is obtained based on the pre-grinding contour information within the effective contact window, and a contour control command is generated accordingly to ensure that the working section of the belt forms a target support contour before reaching the grinding contact area on the corresponding workpiece surface. Subsequently, the effective grinding power is obtained based on the actual working power of the belt and the no-load power corresponding to the belt linear speed. Combined with the width of the effective contact window and the feed speed of the grinding spindle, the grinding energy per unit area is obtained, and a feed speed control command is generated to adjust the grinding action received by the corresponding workpiece surface position.

[0062] More specifically, after the corresponding workpiece surface passes the grinding contact area and continues to move a preset rearward distance, the rearward contour data acquired at this time is associated with the pre-grinding contour information at the same workpiece surface position to complete the spatial correspondence of the pre-grinding and post-grinding contours. The pre-grinding surface normal is obtained based on the pre-grinding contour information, and the positional difference between the pre-grinding surface point and the post-grinding surface point is projected along the pre-grinding surface normal to obtain the actual material removal amount at the corresponding workpiece surface position. The actual material removal amount is compared with the target material removal amount. When the actual material removal amount is less than the target material removal amount, the target unit area grinding energy used for supplementary grinding at that workpiece surface position is increased, and a supplementary grinding command is generated; when the actual material removal amount is greater than the target material removal amount, the target unit area grinding energy used for subsequent corresponding workpiece surface positions is reduced.

[0063] Therefore, contour control commands, feed rate control commands, and supplementary grinding commands are all based on data corresponding to the same workpiece surface position, forming a continuous data processing link for pre-grinding prediction, grinding process control, and post-grinding correction.

[0064] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A grinding system for automotive parts, characterized in that, The system includes: The data acquisition module is used to acquire motion data of the grinding spindle, front contour data, rear contour data and abrasive belt running data. The front contour data includes grinding front contour information and workpiece boundary information. The spatial correspondence module is used to obtain the cumulative trajectory distance based on the motion data, and to correspond the front contour data and the rear contour data to the workpiece surface position in the grinding contact area based on the cumulative trajectory distance. The window analysis module is used to determine the effective contact window based on the workpiece boundary information corresponding to the workpiece surface position, and to obtain the predicted contour based on the pre-grinding contour information within the effective contact window. The forming control module is used to obtain contour control instructions based on the predicted contour, so that the sanding belt working section forms the target support contour before entering the grinding contact area on the corresponding workpiece surface. The energy control module is used to obtain the effective grinding power based on the sanding belt running data, obtain the grinding energy per unit area based on the effective grinding power, the width of the effective contact window and the feed speed of the grinding spindle, and obtain the feed speed control command based on the grinding energy per unit area. The feedback correction module is used to obtain the actual material removal amount based on the pre-grinding contour information and the post-grinding contour data corresponding to the same workpiece surface position, and to correct the target unit area grinding energy or generate supplementary grinding instructions based on the actual material removal amount. The execution control module is used to execute the contour control command, the feed speed control command, and the supplementary grinding command.

2. The grinding system for automotive parts as described in claim 1, characterized in that, The motion data includes trajectory position and feed rate; The spatial correspondence module is used to associate each set of preceding contour data with the corresponding cumulative trajectory distance, and when the difference between the current cumulative trajectory distance and the corresponding cumulative trajectory distance reaches a preset preceding distance, the corresponding preceding contour data is mapped to the workpiece surface position in the grinding contact area.

3. The grinding system for automotive parts as described in claim 2, characterized in that, The spatial correspondence module is also used to associate the acquired rear contour data with the pre-grinding contour information corresponding to the workpiece surface position after the workpiece surface position passes through the grinding contact area and continues to move a preset rear distance.

4. The grinding system for automotive parts as described in claim 1, characterized in that, The window analysis module is specifically used for: The grinding range in the width direction of the abrasive belt is obtained based on the workpiece boundary information, the grinding range is determined as the effective contact window, and the predicted contour is obtained based on the contour height of each detection position within the effective contact window.

5. The grinding system for automotive parts as described in claim 4, characterized in that, The forming control module is specifically used for: The contour height and average contour height of each detection position in the predicted contour are obtained. The target support contour is determined based on the height difference between each contour height and the average contour height, and the corresponding contour control command is obtained.

6. The grinding system for automotive parts as described in claim 1, characterized in that, The abrasive belt operating data includes actual operating power and abrasive belt linear speed; The energy control module is specifically used for: The no-load power is obtained based on the abrasive belt linear velocity. The difference between the actual working power and the no-load power is determined as the effective grinding power. The feed speed control command is generated based on the deviation between the grinding energy per unit area and the target grinding energy per unit area.

7. The grinding system for automotive parts as described in claim 1, characterized in that, The feedback correction module is specifically used for: Based on the pre-grinding contour information, the pre-grinding surface normal is obtained. The positional difference between the pre-grinding surface point and the post-grinding surface point at the same workpiece surface position is projected along the pre-grinding surface normal to obtain the actual material removal amount. Based on the deviation between the actual material removal amount and the target material removal amount, the target unit area grinding energy is corrected or the supplementary grinding command is generated.

8. A method for polishing automotive parts, characterized in that, The method is based on a polishing system for automotive parts according to any one of claims 1 to 7, and the method includes: Acquire motion data of the grinding spindle, front contour data, rear contour data, and abrasive belt operation data. The front contour data includes grinding front contour information and workpiece boundary information. The cumulative trajectory distance is obtained based on the motion data, and the front contour data and the rear contour data are respectively mapped to the workpiece surface position in the grinding contact area based on the cumulative trajectory distance. The effective contact window is determined based on the workpiece boundary information corresponding to the workpiece surface position, and the predicted contour is obtained based on the pre-grinding contour information within the effective contact window. Based on the predicted contour, a contour control command is obtained to enable the sanding belt working section to form a target support contour before entering the grinding contact area on the corresponding workpiece surface. The effective grinding power is obtained based on the sanding belt operation data. The grinding energy per unit area is obtained based on the effective grinding power, the width of the effective contact window, and the feed speed of the grinding spindle. The feed speed control command is obtained based on the grinding energy per unit area. The actual material removal amount is obtained based on the pre-grinding contour information and the post-grinding contour data corresponding to the same workpiece surface position. The target unit area grinding energy is corrected or a supplementary grinding command is generated based on the actual material removal amount. Execute the contour control command, the feed rate control command, and the supplementary grinding command.

9. A grinding method for automotive parts as described in claim 8, characterized in that, The step of mapping the pre-contour data and post-contour data to the workpiece surface positions in the grinding contact area includes: Associate each set of preceding contour data with the corresponding cumulative trajectory distance; When the difference between the current cumulative trajectory distance and the corresponding cumulative trajectory distance reaches a preset preceding distance, the corresponding preceding contour data is mapped to the grinding contact area; After passing through the grinding contact area at the corresponding workpiece surface position and continuing to move a preset rear distance, the acquired rear contour data is associated with the pre-grinding contour information at the workpiece surface position.

10. A grinding method for automotive parts as described in claim 8, characterized in that, The step of adjusting the target unit area grinding energy or generating and executing supplementary grinding instructions based on the actual material removal amount includes: The surface normal before grinding is obtained based on the pre-grinding contour information; The positional difference between a point on the surface before grinding and a point on the surface after grinding at the same workpiece surface position is projected along the normal of the surface before grinding to obtain the actual amount of material removed. When the actual material removal amount is less than the target material removal amount, the grinding energy per unit area of ​​the corresponding workpiece surface position is increased and supplementary grinding is performed; when the actual material removal amount is greater than the target material removal amount, the grinding energy per unit area of ​​the subsequent corresponding workpiece surface position is reduced.

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