Device and method for automatically replacing abrasive paper by robot in anti-explosion environment

Abstract

The invention relates to the field of automatic polishing of aerospace composite materials, in particular to a device and method for automatically replacing abrasive paper through a robot in an anti-explosion environment. The device comprises an abrasive paper storage device, an abrasive paper stripping device and an abrasive paper replacement structure, the abrasive paper storage device and the abrasive paper stripping device are arranged on the frame body, and the abrasive paper storage device is connected with the abrasive paper stripping device; the frame body is provided with an abrasive paper detection device used for detecting whether abrasive paper is replaced or not. The abrasive paper replacement structure comprises an abrasive paper dust collection disc; one surface of the abrasive paper dust collection disc is connected with a dust collection hole polishing head at the tail end of the robot; holes formed in the abrasive paper dust collection disc are aligned with dust collection holes in the dust collection hole polishing head. An annular groove is formed in the other face of the abrasive paper dust collection disc, and the multiple holes are formed in the annular groove. According to the abrasive paper replacing device, abrasive paper replacing efficiency is higher, and abrasive paper replacing is more convenient.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aerospace composite material automatic polishing, in particular to a robot automatic sandpaper changing device and method in an explosion-proof environment. BACKGROUND

[0002] For the problem of automatic high-precision polishing of large and complex composite material wall panels and other workpieces in the aerospace field, the conventional technical solution is to use manual polishing tools for polishing work. The polishing quality of the workpiece is greatly affected by the technical level of the operator and the efficiency is low. The polishing process is noisy and dusty, the environment is harsh, and it can seriously affect the physical and mental health of workers. Therefore, using automatic polishing can effectively improve the polishing efficiency and quality, reduce the impact of the polishing environment on workers' health, and realize the high-precision, high-efficiency, and green production mode of large aircraft composite parts.

[0003] In the existing automatic polishing process of composite materials, the high frequency of sandpaper changing process caused by large sandpaper consumption, the existing automatic sandpaper changing device and process flow have problems such as long detection time, low efficiency (i.e. the sandpaper changing process time accounts for a large proportion of the entire polishing process), not suitable for environments with combustible dust generated by composite material polishing, low safety, etc. In particular, in order to reduce the concentration of combustible dust in the composite material polishing environment and improve safety, a polishing head with a dust suction hole is selected, so there is a problem of difficulty in aligning the dust suction hole on the sandpaper and the dust suction hole of the polishing head when changing the sandpaper.

[0004] For example, a Chinese patent with publication number CN107199508A and publication date September 26, 2017, entitled "Intelligent sandpaper changing device for robot polishing and polishing" invention patent, its technical solution is as follows: The invention provides an intelligent sandpaper changing device for robot polishing and polishing, which comprises a sandpaper removing device and a sandpaper sticking device; the sandpaper removing device comprises a cutting-in plate, a parallel bearing mechanism and a frame structure, the cutting-in plate and the parallel bearing mechanism are connected on the frame structure, the cutting-in plate has a cutting-in port for cutting between the polishing machine and the sandpaper; the sandpaper sticking device comprises a profile storage mechanism, a detection mechanism and a sliding block guide rail mechanism, the profile storage mechanism comprises a sandpaper retaining ring, a lower support plate, a support rod, a tray and a mounting plate, the support rod is connected between the sandpaper retaining ring and the lower support plate, the movable part is connected on the sliding block guide rail mechanism, the tray is located between the sandpaper retaining ring and the lower support plate and is connected on the mounting plate, the stationary part, the movable part moves downward according to the combined force of its own gravity and the friction force between the sliding block and the guide rail in the guide rail sliding block mechanism.

[0005] The above patent can realize automatic replacement of sandpaper, reduce the dependence of sandpaper replacement on people, and reduce the labor cost of enterprises, but the above patent needs to detect whether the sandpaper exists on the robot through a sensor, which may have the problems of high use cost and complex detection method, and also cannot solve the technical problem that if a polishing head with a dust suction hole is selected, the sandpaper needs to be installed hole-to-hole, thereby causing low installation efficiency. SUMMARY

[0006] In order to solve the problems existing in the prior art, the present application provides a robot automatic sandpaper replacement device and method in an explosion-proof environment without the need for aligning dustproof holes to quickly replace sandpaper.

[0007] In order to achieve the above technical effects, the technical scheme of the present application is as follows: In a first aspect, a robot automatic sandpaper replacement device in an explosion-proof environment includes a sandpaper storage device, a sandpaper peeling device, and a sandpaper replacement structure; the sandpaper storage device and the sandpaper peeling device are arranged on a frame body and are connected; the frame body is provided with a sandpaper detection device for detecting whether the sandpaper is replaced; the sandpaper replacement structure includes a sandpaper dust suction disc; one side of the sandpaper dust suction disc is connected with a dust suction hole polishing head at the end of the robot; the holes arranged on the sandpaper dust suction disc are aligned with the dust suction holes on the dust suction hole polishing head; the other side of the sandpaper dust suction disc is provided with an annular groove, and a plurality of holes are arranged on the annular groove.

[0008] Further, the annular groove is a plurality of annular grooves; the plurality of annular grooves are distributed in a concentric circle shape with the center of the sandpaper dust suction disc as the center.

[0009] Further, the center of the sandpaper dust suction disc is provided with a circular groove, and the center of the circular groove is provided with a hole; the hole is aligned with a dust suction hole in the center of the dust suction hole polishing head.

[0010] Further, the hole diameter of the hole of the sandpaper dust suction disc is equal to the hole diameter of the dust suction hole of the dust suction hole polishing head; the hole diameter of the hole and the hole diameter of the dust suction hole are both in the range of 5mm to 7mm.

[0011] Further, the sandpaper detection device comprises a top rod, an explosion-proof mechanical touch switch and a signal processing module; the top rod is installed below the sandpaper stripping sheet through a support frame; the support frame is arranged at the bottom of the sandpaper stripping sheet of the sandpaper stripping device; the explosion-proof mechanical touch switch is arranged on the support frame and in contact with the end of the top rod; the explosion-proof mechanical touch switch is connected with the signal processing module; the sandpaper stripping sheet of the sandpaper stripping device is provided with a through hole, and the top of the top rod passes through the through hole of the sandpaper stripping sheet; the signal processing module is arranged in an explosion-proof electrical box; the signal processing module is connected with the controller through a signal, and the controller is arranged in the explosion-proof electrical box.

[0012] Further, the sandpaper storage device comprises a storage barrel; the storage barrel is arranged at the top of the frame body.

[0013] Further, the top of the storage barrel is provided with a sandpaper cover plate for preventing polishing dust from entering the storage barrel; the sandpaper cover plate is connected with the cylinder shaft of the sandpaper ejection cylinder through a cam; the top of the cylinder shaft of the sandpaper ejection cylinder is provided with a sandpaper tray.

[0014] Further, the sandpaper stripping device comprises a sandpaper stripping guide roller and a sandpaper stripping sheet; the sandpaper stripping guide roller is arranged at the top of the frame body; a sandpaper stripping sheet is arranged beside the sandpaper stripping guide roller and fixed at the top of the frame body.

[0015] Further, one side of the frame body is provided with a waste sandpaper collecting device for storing waste sandpaper.

[0016] Further, the frame body is further provided with an explosion-proof electrical box for mounting electrical elements.

[0017] Further, the controller is connected with an operation table outside, and the operation table is provided with a man-machine control interface and an audible and visual alarm.

[0018] In the second aspect, a robot automatic sandpaper changing method in an explosion-proof environment is realized based on the robot automatic sandpaper changing device in an explosion-proof environment in the first aspect, comprising the following method steps: Step S1: when the robot executes a sandpaper changing command, the end of the robot first passes through the sandpaper stripping device to perform a sandpaper stripping process to strip the sandpaper from the sandpaper dust collection disc; Step S2: after the sandpaper is stripped, the sandpaper dust collection disc at the end of the robot is determined by the sandpaper detection device whether there is still sandpaper; Step S3: When it is determined that there is no sandpaper, the end of the robot moves above the storage barrel, at this time the sandpaper cover plate is opened, the sandpaper is ejected from the sandpaper ejection cylinder, the hole of the sandpaper is matched with the annular groove on the sandpaper dust collection disc of the end of the robot, and the replacement of the sandpaper is completed.

[0019] Further, in the step S2, when there is no sandpaper on the sandpaper dust collection disc, the sandpaper detection device cannot be pressed down by passing through the dust collection hole in the center of the dust collection hole polishing head and the hole in the center of the sandpaper dust collection disc, and then a disconnection signal is output to the controller through the signal processing module to determine that there is no sandpaper, and then the step S3 is continued to be executed; when there is sandpaper on the sandpaper dust collection disc, the sandpaper detection device is pressed down because the hole diameter of the through hole of the sandpaper is smaller than the rod diameter of the ejector rod, the anti-explosion mechanical touch switch is touched, a closure signal is output to the controller through the signal processing module to determine that there is sandpaper, and then the step S1 is returned to; if it is still determined that there is sandpaper after three times, the controller transmits a signal to the audible and visual alarm of the operation platform to issue an alarm and stop, and the cycle is prevented from being entered.

[0020] Further, the hole diameter of the dust collection hole in the center of the dust collection hole polishing head and the hole diameter of the hole in the center of the sandpaper dust collection disc are both greater than the rod diameter of the ejector rod; and the hole diameter of the through hole of the sandpaper is smaller than the rod diameter of the ejector rod.

[0021] Further, in the step S3, after the replacement of the sandpaper is completed, the sandpaper dust collection disc of the end of the robot is moved upward, and the sandpaper ejection cylinder is driven to close the sandpaper cover plate.

[0022] Further, after the sandpaper cover plate is closed, the end of the robot presses the replaced sandpaper on the sandpaper cover plate with a force of 20N or more.

[0023] Further, after the replacement of the sandpaper is completed, the robot starts to execute the polishing process, and moves to the sandpaper detection device according to a preset period of time to detect whether there is sandpaper on the sandpaper dust collection disc; if it is determined that there is sandpaper, the polishing position is returned to continue to execute the polishing process; if it is determined that there is no sandpaper, the step S3 is executed, and the sandpaper detection device is detected again; when the step S3 is repeated three times, it is still determined that there is no sandpaper after detection, the controller transmits a signal to the audible and visual alarm of the operation platform to issue an alarm and stop, and the cycle is prevented from being entered.

[0024] According to the above technical solution, the present application has the following beneficial effects: 1. The device of the present application realizes that when the sandpaper is replaced, the dislocation space of the dust collection hole and the hole of the sandpaper dust collection disc is provided through the annular groove and the circular groove on the sandpaper dust collection disc, so that the through hole on the sandpaper and the dust collection hole on the dust collection hole polishing head do not need to be aligned, the efficiency of replacing the sandpaper is higher, and it is more convenient.

[0025] 2. The method of the present application, compared with the method in the prior art, no longer uses the alignment detection process and brake fixing device in the traditional method, realizes the complete alignment of the dust suction hole of the polishing head on the sandpaper, simplifies the process and structure of the robot automatic sandpaper replacement, and greatly improves the efficiency and convenience of the automatic sandpaper replacement.

[0026] 3. The device of the present application, compared with the sandpaper replacement detection in the prior art, has higher convenience, faster detection speed, and simpler setting mode, and lower cost.

[0027] 4. In the device of the present application, the sandpaper cover plate is arranged on the storage barrel to prevent polishing dust from entering the storage barrel and polluting the sandpaper, and to ensure the safety of the polishing process.

[0028] 5. In the device of the present application, the explosion-proof electrical box is adopted to prevent the polishing dust from entering the electrical components and causing short circuit of the components, and to cause failure or explosion. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a partial structure diagram of the present application.

[0030] Figure 2 is a structure diagram of the polishing head installation of the end of the robot.

[0031] Figure 3 is a structure diagram of the sandpaper dust collection disc and sandpaper separation of the end of the robot.

[0032] Figure 4 is a structure diagram of the dust suction hole polishing head, sandpaper dust collection disc and sandpaper separation of the end of the robot.

[0033] Figure 5 is a perspective view of the sandpaper dust collection disc.

[0034] Figure 6 is a front view of the sandpaper dust collection disc.

[0035] Figure 7 is a cross-sectional view of the sandpaper dust collection disc.

[0036] Figure 8 is a flow diagram of the method of the present application.

[0037] In the drawings: 1 - storage barrel; 2 - sandpaper cover plate; 3 - sandpaper ejection cylinder; 4 - sandpaper peeling guide roller; 5 - sandpaper peeling piece; 6 - sandpaper detection device; 7 - waste sandpaper collection device; 8 - explosion-proof electrical box; 9 - dust suction hole polishing head; 10 - sandpaper dust collection disc; 11 - sandpaper. DETAILED EMBODIMENT To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0039] Example 1 like Figure 1 As shown, an automatic sandpaper changing device for robots in an explosion-proof environment includes a sandpaper storage device, a sandpaper peeling device, and a sandpaper changing structure. The sandpaper storage device and the sandpaper peeling device are mounted on a frame and connected by a support structure, which also supports the external dustproof housing of the sandpaper storage device and the sandpaper peeling device to improve the overall structural rigidity. A sandpaper detection device 6 is provided on the frame to detect whether the sandpaper 11 has been changed; the sandpaper detection device 6 is an explosion-proof mechanical sandpaper detection device. The sandpaper changing structure includes a sandpaper dust collection disc 10. Figure 3 and Figure 4 As shown, one side of the sandpaper dust collection disc 10 is connected to the dust collection hole grinding head 9 at the end of the robot; the holes on the sandpaper dust collection disc 10 are aligned with the dust collection holes on the dust collection hole grinding head 9, and the dust collection hole grinding head 9 has its own dust collection holes for easy dust collection; as shown Figure 5 As shown, an annular groove is provided on the other side of the sandpaper dust collection disc 10, and multiple holes are provided on the annular groove; the groove width of the annular groove is the same as the diameter of the dust collection holes.

[0040] The robot and the automated sandpaper changing device can be mounted on a mobile skateboard, allowing both to move simultaneously while maintaining their relatively fixed positions.

[0041] like Figure 5 , Figure 6 and Figure 7 As shown, when sandpaper 11 needs to be installed onto the sandpaper suction disc 10 at the end of the robot, since an annular groove is provided on one side of the sandpaper suction disc 10, the annular groove can provide misalignment space between the through hole of the sandpaper 11 and the hole of the sandpaper suction disc 10. This ensures that even if the through hole of the sandpaper 11 and the hole of the sandpaper suction disc 10 are misaligned or angularly offset, the suction effect of the hole will not be affected. Therefore, the through hole on the sandpaper 11 does not need to be aligned with the hole on the sandpaper suction disc 10. The design of this device makes the installation of sandpaper 11 faster and more convenient, and eliminates the need for alignment detection procedures and brake fixing devices in existing technologies, thus improving the convenience of replacing sandpaper 11.

[0042] Example 2 Based on Embodiment 1, in this embodiment, there are multiple annular grooves; such as Figure 5 and Figure 6As shown, the plurality of annular grooves are distributed in concentric circles with the center of the sandpaper dust collection disc 10 as the center. The hole diameter of the hole of the sandpaper dust collection disc 10 is equal to the hole diameter of the dust collection hole of the dust collection hole polishing head 9; the hole diameter of the hole and the hole diameter of the dust collection hole are both in the range of 5mm to 7mm. The center of the sandpaper dust collection disc 10 is provided with a circular groove, and the center of the circular groove is provided with a hole, as shown in Figure 6 The hole can be a "cross" type hole, and the hole diameter of the hole is larger than the hole diameter of the other holes of the sandpaper dust collection disc 10, and the hole is aligned with a dust collection hole at the center of the dust collection hole polishing head 9.

[0043] As shown in Figure 1 The sandpaper detection device 6 includes a top rod, an explosion-proof mechanical touch switch and a signal processing module; the top rod is installed below the sandpaper stripping sheet 5 through a support frame; the support frame is arranged at the bottom of the sandpaper stripping sheet 5 of the sandpaper stripping device; the explosion-proof mechanical touch switch is arranged on the support frame and is in contact with the end of the top rod; the explosion-proof mechanical touch switch is connected with the signal processing module; the sandpaper stripping sheet 5 of the sandpaper stripping device is provided with a through hole, and the top of the top rod passes through the through hole of the sandpaper stripping sheet 5; the signal processing module is arranged in the explosion-proof electrical box 8; the top rod is installed below the sandpaper stripping sheet 5 through the support frame, which is a known installation method for those skilled in the art, and can also be assembled with the top rod by setting a guide sleeve, etc., which will not be described here; the signal processing module is connected with the controller through a signal, and the controller is arranged in the explosion-proof electrical box 8; the controller, the explosion-proof mechanical switch and the signal processing module are all devices in the prior art in the field, which will not be described here; the controller is connected with the operating table outside, and the operating table is provided with a man-machine control interface and an audible and visual alarm, and the operating table is a prior art in the field, which can realize the alarm and interface control functions by connecting the existing equipment, and this technology is not the innovation of the present application, which will not be described here. The frame body is also provided with an explosion-proof electrical box 8 for installing electrical elements, and the box body of the explosion-proof electrical box 8 adopts positive pressure explosion-proof; the electrical elements are non-explosion-proof electrical elements, which are put into the explosion-proof electrical box 8 to avoid the hidden danger of explosion.

[0044] As shown in Figure 1 The sandpaper storage device includes a storage barrel 1; the storage barrel 1 is arranged at the top of the frame body; the top of the storage barrel 1 is provided with a sandpaper cover plate 2 for preventing polishing dust from entering the storage barrel; the sandpaper cover plate 2 is connected with the cylinder shaft of the sandpaper 11 ejecting cylinder through a cam; the top of the cylinder shaft of the sandpaper 11 ejecting cylinder is provided with a sandpaper 11 tray; the sandpaper 11 ejecting cylinder works to eject the sandpaper 11 through the sandpaper 11 tray, and at the same time drives the cam to open the sandpaper cover plate 2, so as to realize the pasting of the sandpaper 11 to the end of the robot.

[0045] As shown in Figure 1As shown, the sandpaper peeling device includes a sandpaper peeling guide roller 4 and a sandpaper peeling plate 5. The sandpaper peeling guide roller 4 is located on the top of the frame and is used to guide the linear motion of the robot's end effector, reducing frictional resistance during the motion. The sandpaper peeling plate 5 is located next to the sandpaper peeling guide roller 4 and is fixed to the top of the frame. A waste sandpaper collection device 7 for storing waste sandpaper 11 is located on one side of the frame.

[0046] The specific method for peeling sandpaper 11 is as follows: The robot first drives its end effector to move directly above the guide roller and moves vertically downwards until it contacts the guide roller. Finally, the robot's end effector slowly moves in a straight line along the guide roller towards the sandpaper peeling disc 5. Because the height of the sandpaper peeling disc 5 is designed to be between the sandpaper 11 and the dust collection disc, the front end of the sandpaper peeling disc 5 first inserts between the sandpaper 11 and the sandpaper dust collection disc 10 during the robot's movement. When the robot has completed the path of peeling sandpaper 11, the sandpaper 11 is completely peeled off and enters the waste sandpaper collection device 7.

[0047] Example 3 like Figure 8 As shown, a method for automatically changing sandpaper using a robot in an explosion-proof environment, based on the automatic sandpaper changing device for a robot in an explosion-proof environment described in Example 2, includes the following steps: Step S1: When the robot executes the command to replace sandpaper 11, the robot's end effector first passes through the sandpaper peeling device to peel sandpaper 11 off from the sandpaper dust collection disc 10. Step S2: After the sandpaper 11 is peeled off, the sandpaper dust collection disc 10 at the end of the robot determines whether sandpaper 11 still exists through the sandpaper detection device 6. Step S3: When it is determined that there is no sandpaper 11, the end effector of the robot moves above the storage bin 1. At this time, the sandpaper cover plate 2 is opened, and the sandpaper ejection cylinder 3 ejects the sandpaper 11, so that the holes of the sandpaper 11 fit into the annular groove on the sandpaper dust collection disc 10 at the end effector of the robot. Figure 2 As shown, the sandpaper 11 has been replaced.

[0048] Before executing step S1, the number of grinding points can be counted. Each time a point is ground, the count is automatically incremented by 1. When the number of grinding points is greater than or equal to the set value, the subroutine for changing sandpaper 11 is automatically called, thus starting to execute step S1.

[0049] Example 4 Based on Example 3, such as Figure 8As shown, in step S2, when there is no sandpaper 11 on the sandpaper dust collection disc 10, the sandpaper detection device 6 cannot be pressed through the dust collection hole in the center of the polishing head 9 and the hole in the center of the sandpaper dust collection disc 10, and then the disconnection signal is output to the controller through the signal processing module, and then it is determined that there is no sandpaper 11, and then step S3 is continued; when there is sandpaper 11 on the sandpaper dust collection disc 10, the sandpaper 11 will press the top rod because the aperture of the through hole of the sandpaper 11 is smaller than the rod diameter of the top rod of the sandpaper detection device 6, and the anti-explosion mechanical touch switch is touched, and then the closure signal is output to the controller through the signal processing module, and then it is determined that there is sandpaper 11, and then it returns to step S1; if it is still determined that there is sandpaper 11 after three times, the controller transmits a signal to the audible and visual alarm of the operation platform to issue an alarm and stop, preventing entering a dead loop; the aperture of the dust collection hole in the center of the polishing head 9 and the aperture of the hole in the center of the sandpaper dust collection disc 10 are both larger than the rod diameter of the top rod; the aperture of the through hole of the sandpaper 11 is smaller than the rod diameter of the top rod; wherein the aperture of the dust collection hole in the center of the polishing head 9 and the aperture of the hole in the sandpaper dust collection disc 10 can be set to 10 mm, the aperture of the through hole of the sandpaper 11 can be set to 6 mm, and the rod diameter of the top rod of the sandpaper detection device 6 can be set to 8 mm.

[0050] After the replacement of the sandpaper 11 is completed in step S3, the sandpaper dust collection disc 10 at the end of the robot moves upward, and at the same time, the sandpaper ejection cylinder 3 drives the sandpaper cover plate 2 to close; after the sandpaper cover plate 2 is closed, the end of the robot presses the replaced sandpaper 11 on the sandpaper cover plate 2 with a force of 20 N or more, so as to ensure that the sandpaper 11 is closely and effectively attached to the sandpaper dust collection disc 10; the sandpaper is a general sandpaper with a back velvet and a polishing machine hook surface adhesion on the market.

[0051] After the replacement of the sandpaper 11 is completed, the robot starts to perform the polishing process, and moves to the sandpaper detection device 6 according to the preset period of time to detect whether there is sandpaper 11 on the sandpaper dust collection disc 10; if it is determined that there is sandpaper 11, it returns to the polishing position to continue the polishing process; if it is determined that there is no sandpaper 11, step S3 is performed, and the detection is performed again on the sandpaper detection device 6; when step S3 is repeated three times, and it is still determined that there is no sandpaper 11 after detection, the controller transmits a signal to the audible and visual alarm of the operation platform to issue an alarm and stop, preventing entering a dead loop.

[0052] In order to improve the control accuracy of replacing the sandpaper 11 in the embodiment, the following control method is also provided: the industrial robot will contact the surface of the composite material wing wall plate during polishing, how to accurately control the constant force contact between the robot and the composite material wing wall plate and accurately polish and end pose compensation, which has a very important role and significance for the processing quality of the surface treatment of the composite material wing wall plate and the accuracy of automatically replacing the sandpaper 11.

[0053] The dynamic equation when the end of the robot contacts the external polishing environment can be expressed as:

[0054] wherein: is the selected robot generalized coordinate position, is the robot generalized velocity, is the robot generalized acceleration, is the positive inertia matrix, is the Coriolis force term, centrifugal force term, etc. is the gravity term, is the joint friction torque, is the robot joint drive torque, is the environmental disturbance torque to the robot, thus obtaining the end-constrained control system model of the industrial robot.

[0055] The above dynamic equation embodies the action law when the end of the robot contacts with the external polishing environment, and also serves as a guiding equation for the mechanical control in the sandpaper 11 peeling program; the robot joint drive torque minus the effect of the environmental disturbance torque to the robot in the equation is used to obtain the actual drive torque of the end of the robot, which is used to control the polishing motion speed.

[0056] Let According to the relationship between the robot joint space and the operation space, the dynamic equation of the robot operation space is obtained as:

[0057] wherein: X is the robot space displacement matrix; the relationship between the polishing end Coriolis force, centrifugal force and gravity of the robot operation space and the vector matrix is ; the positive inertia force ; the friction force ; the robot joint drive force ; the environmental disturbance force ; the normal contact pressure ; wherein is the matrix, is the contact torque.

[0058] Through the above dynamic equation, and by setting a force sensor at the end of the robot, the environmental position and the polishing contact force are fed back in real time, the trajectory dynamic correction is controlled, the end pose compensation is superimposed with the pre-planned trajectory position as the input of the robot position control system, so as to realize the accurate displacement control of the entire sandpaper changing process along the offline programming trajectory of the robot, improve the position accuracy and the success rate of changing the sandpaper 11; the above dynamic equation is only an example, and the remaining dynamic equations are not described herein, and the above dynamic equation is the prior art in the art.

[0059] The above description is detailed for the preferred embodiments of the present application, but the embodiments are not intended to limit the scope of the patent application of the present application. Any equivalent changes or modifications made under the technical spirit of the present application should belong to the patent scope of the present application.

Claims

1. A robotic automatic sandpaper changing device for use in explosion-proof environments, characterized in that: The system includes a sandpaper storage device, a sandpaper peeling device, and a sandpaper replacement structure. The sandpaper storage device and the sandpaper peeling device are mounted on a frame and connected to each other. The frame is equipped with a sandpaper detection device (6) for detecting whether the sandpaper (11) has been replaced. The sandpaper replacement structure includes a sandpaper dust collection disc (10). One side of the sandpaper dust collection disc (10) is connected to the dust collection hole grinding head (9) at the end of the robot. The holes on the sandpaper dust collection disc (10) are aligned with the dust collection holes on the dust collection hole grinding head (9). The other side of the sandpaper dust collection disc (10) is provided with an annular groove, and the annular groove is provided with multiple holes.

2. The automatic sandpaper changing device for robots in an explosion-proof environment according to claim 1, characterized in that: The annular grooves are multiple; the multiple annular grooves are distributed in a concentric circle with the center of the sandpaper dust collection disc (10) as the center.

3. The automatic sandpaper changing device for robots in an explosion-proof environment according to claim 2, characterized in that: The sandpaper dust collection disc (10) has a circular groove in the center, and a hole in the center of the circular groove; the hole is aligned with a dust collection hole in the center of the dust collection hole grinding head (9).

4. The automatic sandpaper changing device for robots in an explosion-proof environment according to claim 2, characterized in that: The diameter of the hole in the sandpaper dust collection disc (10) is equal to the diameter of the dust collection hole in the dust collection hole grinding head (9); the diameter of the hole and the diameter of the dust collection hole are both in the range of 5mm to 7mm.

5. The automatic sandpaper changing device for robots in an explosion-proof environment according to claim 1, characterized in that: The sandpaper detection device (6) includes a top rod, an explosion-proof mechanical touch switch and a signal processing module; the top rod is installed below the sandpaper peeling plate (5) via a support frame; the support frame is located at the bottom of the sandpaper peeling plate (5) of the sandpaper peeling device; The explosion-proof mechanical touch switch is mounted on the support frame and contacts the end of the top rod; the explosion-proof mechanical touch switch is connected to the signal processing module; the sandpaper peeling plate (5) of the sandpaper peeling device has a through hole, and the top of the top rod passes through the through hole of the sandpaper peeling plate (5); the signal processing module is mounted in the explosion-proof electrical box (8); the signal processing module is connected to the controller via a signal, and the controller is mounted in the explosion-proof electrical box (8).

6. The automatic sandpaper changing device for robots in an explosion-proof environment according to claim 1, characterized in that: The sandpaper storage device includes a storage bin (1); the storage bin (1) is located on the top of the frame.

7. The automatic sandpaper changing device for robots in an explosion-proof environment according to claim 6, characterized in that: The top of the storage hopper (1) is provided with a sandpaper cover plate (2) to prevent grinding dust from entering the storage hopper; the sandpaper cover plate (2) is connected to the cylinder shaft of the sandpaper ejection cylinder (3) through a cam; a sandpaper tray is provided on the top of the cylinder shaft of the sandpaper ejection cylinder (3).

8. The automatic sandpaper changing device for robots in an explosion-proof environment according to claim 5, characterized in that: The sandpaper peeling device includes a sandpaper peeling guide roller (4) and a sandpaper peeling plate (5); the sandpaper peeling guide roller (4) is located on the top of the frame; a sandpaper peeling plate (5) is located on one side of the sandpaper peeling guide roller (4) and is fixed to the top of the frame.

9. The automatic sandpaper changing device for robots in an explosion-proof environment according to claim 1, characterized in that: A waste sandpaper collection device (7) for storing waste sandpaper (11) is provided on one side of the frame.

10. The automatic sandpaper changing device for robots in an explosion-proof environment according to claim 5, characterized in that: The frame is also equipped with an explosion-proof electrical box (8) for installing electrical components.

11. The automatic sandpaper changing device for robots in an explosion-proof environment according to claim 5, characterized in that: The controller is connected to an external control panel, and the control panel is equipped with a human-machine interface and an audible and visual alarm.

12. A method for automatically changing sandpaper using a robot in an explosion-proof environment, characterized in that, The automatic sandpaper changing robot in an explosion-proof environment, based on any one of claims 1 to 11, includes the following method steps: Step S1: When the robot executes the command to change sandpaper (11), the end of the robot first passes through the sandpaper peeling device to peel the sandpaper (11) off from the sandpaper dust collection tray (10). Step S2: After the sandpaper (11) is peeled off, the sandpaper dust collection disc (10) at the end of the robot determines whether there is still sandpaper (11) through the sandpaper detection device (6). Step S3: When it is determined that there is no sandpaper (11), the end of the robot moves to the top of the storage bucket (1). At this time, the sandpaper cover plate (2) is opened, and the sandpaper ejection cylinder (3) ejects the sandpaper (11) so that the hole of the sandpaper (11) fits into the annular groove on the sandpaper dust collection disc (10) at the end of the robot, thus completing the replacement of the sandpaper (11).

13. A method for automatically changing sandpaper by a robot in an explosion-proof environment according to claim 12, characterized in that, In step S2, when there is no sandpaper (11) on the sandpaper dust collection disc (10), the sandpaper detection device (6) will pass through the dust collection hole in the center of the dust collection hole grinding head (9) and the hole in the center of the sandpaper dust collection disc (10) and cannot be pressed down. Then, the signal processing module outputs a disconnect signal to the controller to determine that there is no sandpaper (11) and continues to execute step S3. When there is sandpaper (11) on the sandpaper dust collection disc (10), since the diameter of the through hole of the sandpaper (11) is smaller than the diameter of the top rod of the sandpaper detection device (6), the top rod will be pressed down and touch the explosion-proof mechanical touch switch. The signal processing module outputs a closed signal to the controller to determine that there is sandpaper (11) and returns to step S1. If it is still determined that there is sandpaper (11) after three times, the controller transmits a signal to the sound and light alarm on the operating table to issue an alarm and stop the machine to prevent entering the loop.

14. The method for automatically changing sandpaper by a robot in an explosion-proof environment according to claim 13, characterized in that, The diameter of the dust suction hole in the center of the dust suction hole grinding head (9) and the diameter of the hole in the center of the sandpaper dust suction disc (10) are both larger than the diameter of the top rod; the diameter of the through hole of the sandpaper (11) is smaller than the diameter of the top rod.

15. A method for automatically changing sandpaper by a robot in an explosion-proof environment according to claim 12, characterized in that, After the sandpaper (11) is replaced in step S3, the sandpaper dust collection disc (10) at the end of the robot moves upward and simultaneously drives the sandpaper ejection cylinder (3) to close the sandpaper cover plate (2).

16. A method for automatically changing sandpaper by a robot in an explosion-proof environment according to claim 15, characterized in that, After the sandpaper cover plate (2) is closed, the end of the robot presses the replaced sandpaper (11) on the sandpaper cover plate (2) with a force of more than 20N.

17. A method for automatically changing sandpaper by a robot in an explosion-proof environment according to claim 16, characterized in that, After the sandpaper (11) is replaced, the robot starts to perform the polishing process and moves to the sandpaper detection device (6) according to the preset cycle time to check whether there is still sandpaper (11) on the sandpaper dust collection tray (10). If it is determined that there is sandpaper (11), it returns to the polishing position to continue the polishing process. If it is determined that there is no sandpaper (11), it executes step S3 and moves to the sandpaper detection device (6) again for detection. When step S3 is executed three times and it is still determined that there is no sandpaper (11) after detection, the controller sends a signal to the sound and light alarm on the operating table to issue an alarm and stop the machine to prevent it from entering the loop.

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