A gantry double-arm robot for sandblasting of a ship

Abstract

The application discloses a gantry double-arm robot for ship sand blasting, and relates to the technical field of automatic production. The robot comprises a gantry, a mechanical arm installed on the gantry, a plurality of connecting rods fixedly connected to the mechanical arm, a sand blasting assembly installed on the mechanical arm, and an output end of the sand blasting assembly arranged on the connecting rods. The robot further comprises a control system. The control system only determines that an inner corner exists on a surface to be sand blasted when at least three groups of data sets with a similarity less than a set value appear, so as to adapt to the dynamic regulation and control requirement of sand blasting in narrow positions in the ship sand blasting process.

Description

Technical Field

[0001] This invention relates to the field of automated production technology, and in particular to a gantry-type dual-arm robot for ship sandblasting. Background Technology

[0002] Marine sandblasting is a key surface treatment process in shipbuilding and maintenance. Its main principle is to use high-speed jets of abrasive to impact the steel surface, removing scale, rust, old coatings, and other contaminants. This results in a clean surface with a certain degree of roughness, providing an ideal substrate for subsequent painting operations. This technology is widely used in hull section construction, dry-docking, and overhaul processes. Its treatment effect (i.e., roughness and uniformity) directly affects coating adhesion and the long-term corrosion resistance of the ship's structure.

[0003] In ship structures, T-plates, as common reinforcing members, are formed by the perpendicular intersection of the web and the face plate. The inner corner area of ​​the supporting position, due to its complex geometry, creates a narrow and difficult-to-reach concave space. Existing technologies for sandblasting these areas mainly include traditional manual sandblasting, improved directional spray guns, and partially automated equipment. Traditional manual sandblasting relies on the operator holding the spray gun and attempting to cover the inner corner surface by adjusting the angle and distance. While this method offers some flexibility, it is limited by ergonomics and visibility; the spray beam cannot vertically impact the bottom of the inner corner, easily creating blind spots.

[0004] To improve accessibility, the industry has developed spray gun designs with optimized aspect ratios, combined with nozzle attachments at different angles, in an attempt to extend the penetration depth of the abrasive flow into inner corners. In addition, localized automation solutions, such as the addition of magnetic wheel-type sandblasting robots, can move along the weld seam trajectory and perform directional sandblasting on specific areas via a preset path. Such equipment reduces the randomness of manual operation to some extent, but its requirements for adaptability to curved surfaces and positioning accuracy remain high, limiting its application in densely structured cabins.

[0005] With the development of machine vision, existing technologies also employ machine vision in conjunction with the aforementioned automated robots for sandblasting of inner corner areas. This approach enhances the automation and accuracy of the process through image recognition, localization, and real-time feedback. However, there are inherent difficulties in the identification and algorithmic processing of the specific target of the inner corner of a T-shaped plate. The inner corner area is essentially a severely occluded, narrow space, and industrial cameras and other visual sensors often only obtain a limited field of view, resulting in severely incomplete data and a high risk of misjudgment or omission. This uncertainty in identification directly threatens the reliability of process decisions. Summary of the Invention

[0006] The purpose of this invention is to provide a gantry-type dual-arm robot for ship sandblasting to solve the above-mentioned problems.

[0007] This invention is achieved through the following technical solution: A gantry-type dual-arm robot for ship sandblasting includes a gantry frame, on which a robotic arm is mounted. Several connecting rods are fixedly connected to the robotic arm. A sandblasting assembly is also mounted on the robotic arm, and the output end of the sandblasting assembly is disposed on the connecting rods. The sandblasting assembly is used to spray abrasive onto the surface to be sandblasted. The robotic arm is used to change the position and angle of the sandblasting assembly. The robotic arm is also equipped with a data acquisition component, which is used to acquire distance information from the output end of the sandblasting assembly to the impact point between the abrasive and the surface to be sandblasted. It also includes a control system, which is used to control the robotic arm to move the connecting rod to the sandblasting position and swing along the set sandblasting angle. The control system is also used to control the sandblasting component and the acquisition component to work alternately, take the distance information acquired by the acquisition component in each continuous time period as a dataset, calculate the mean of each dataset, and calculate the similarity of any three datasets within the same sandblasting angle. Only when at least three sets of datasets have similarity values ​​less than a set value are the presence of an interior angle on the surface to be sandblasted determined. The control system obtains the surface roughness based on the size and distribution of extreme points in the dataset. When the real-time roughness is more similar to a threshold than a set maximum value, the robotic arm is controlled to change the distance between the output end of the sandblasting component and the surface to be sandblasted, as well as the sandblasting angle, until the real-time roughness is no more similar to the threshold than the set maximum value. This solution continuously monitors the distance information from the output end of the sandblasting component to the surface to be sandblasted, thereby determining the spraying position and roughness of the nozzle, to adapt to the dynamic control requirements of sandblasting in confined spaces during ship sandblasting.

[0008] Furthermore, the robotic arm includes a drive unit and a first arm. The top end of the first arm is mounted on the gantry frame, and a second arm is hinged to the bottom end of the first arm. Several third arms are hinged to the second arm, and the connecting rod is hinged to the side wall of the third arm. The drive unit is used to drive the first arm, the second arm, and the third arms to rotate. The control system controls the operation of the drive unit according to the distance information.

[0009] Furthermore, the acquisition component includes a laser emitter and a laser detector. The laser emitter is used to emit laser light towards the surface to be blasted, and the laser detector is used to receive the laser light reflected from the surface to be blasted. The control system acquires distance information based on the time between laser emission and reception.

[0010] Furthermore, the system also includes a brake assembly comprising a ring-shaped outer shell. Inside the outer shell is a retaining ring made of elastic material, which is fixedly connected to the hinge point of the robotic arm. The retaining ring is also eccentrically hinged to the outer shell. The inner wall of the outer shell has several brake pads of equal length, evenly arranged around the axis of the outer shell, and all brake pads are made of shape-memory metal. The outer shell also contains a pulse assembly for changing the temperature of the brake pads. The control system controls the pulse assembly to operate during the robotic arm's working state. This brake assembly design utilizes an eccentrically hinged retaining ring to achieve stepped braking of the robotic arm's hinge position, thereby avoiding damage to the hinge position that may occur due to the instantaneous concentration of impact force in existing braking schemes.

[0011] Furthermore, it also includes a recovery component, which is used to recover the abrasive that bounces off the surface to be blasted. The control system is also used to acquire the blasting parameters input by the user, adjust the duration of a single operation of the acquisition component according to the blasting parameters, and make the acquisition component and the recovery component work synchronously.

[0012] Furthermore, the sandblasting assembly includes a storage assembly for storing abrasive and pressurized gas. The storage assembly is connected to several nozzles via a delivery pipe. An abrasive valve is provided at the connection between the storage assembly and the delivery pipe. All nozzles are fixedly connected to adjacent connecting rods. The control system controls the operation of the abrasive valve and the storage assembly based on distance information.

[0013] Furthermore, it also includes a branch pipe, the input end of which is connected to the storage assembly, and the nozzle is connected to the output end of the branch pipe. The output end of the storage assembly is equipped with a solenoid valve, which is used to change the connection between the pipe and the storage assembly. The control system is also used to collect the flow rates at the input and output ends of the delivery pipe, and to calculate the flow rate difference between the input and output ends of the delivery pipe. Only when the flow rate difference exceeds a set value will the control system send a prompt message to the user and control the solenoid valve to connect the branch pipe to the storage assembly and then close the connection between the delivery pipe and the storage assembly. The design of the branch pipe effectively avoids the significant impact on sandblasting operations caused by damage to the delivery pipe.

[0014] Furthermore, the control system is also used to adjust the robotic arm based on distance information after the branch pipe is opened. If the roughness of the blasted surface is still uneven, the system controls the material storage assembly to change the flow rate and pressure of the ejected abrasive based on the roughness. This design effectively reduces the problem of decreased blasting effect after damage to the branch pipe.

[0015] Furthermore, the recovery assembly includes a negative pressure pump and a sand suction pipe. The sand suction pipe is installed on the robotic arm, and the output end of the sand suction pipe goes to the collection tank. The negative pressure pump is used to generate negative pressure in the sand suction pipe. The sand suction pipe is used to collect the abrasive material that bounces off the surface to be sandblasted. The control system is also used to control the negative pressure pump to work while the collection assembly is working.

[0016] Furthermore, the abrasive is made of magnetic material, the recycling component includes a magnetic field generator, the magnetic field generator is used to change the magnetic field of the surface to be blasted, and the control system is used to control the operation of the magnetic field generator according to the position of the impact point of the abrasive on the surface to be blasted.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. In this invention, the distance information from the output end of the abrasive to the impact point between the abrasive and the surface to be sandblasted is obtained by a laser emitter and a laser detector, thereby determining whether an inner angle appears on the surface to be sandblasted. After an inner angle appears, the sandblasting angle and distance are adjusted in real time according to the change in the roughness of the sandblasted surface during the reciprocating oscillation process, so as to reduce the adverse effect on the final roughness of the surface to be sandblasted after the abrasive repeatedly bounces on the two planes of the inner angle. Compared to existing image recognition technologies, the sensors used in this solution are smaller in size than industrial cameras, allowing them to follow the nozzle into relatively confined spaces as the robotic arm moves. This provides a significant advantage when dealing with the narrow spaces of ship T-beam support locations. Furthermore, because the sensors in this solution can enter relatively confined spaces, data acquisition is less affected by the working environment, resulting in higher accuracy. In addition, the simultaneous data acquisition and sandblasting in this solution enables real-time adjustments to the sandblasting operation, thereby further improving the sandblasting effect. Compared to solutions that use baffles to block the rebounding abrasive from impacting another plane, this solution has a smaller nozzle size, avoiding the problem of baffles getting stuck in confined spaces and affecting sandblasting. In addition, the abrasive in this solution causes less wear on the overall device, and there is no need for frequent replacement after the operation is completed. The long-term cost is low, which can meet the requirements of large-scale engineering projects such as ships for the durability and economy of sandblasting equipment.

[0018] 2. The present invention also utilizes the design of a recycling component to promptly recover the abrasive, thereby reducing the adverse impact of rebounding abrasive on data acquisition. Compared to existing technologies, this solution enables the recovery component to work synchronously with the collection component, allowing sandblasting and abrasive recovery to proceed simultaneously, effectively improving the efficiency of sandblasting operations. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 This is a top cross-sectional view of the present invention; Figure 4 This is a top sectional view of the brake assembly; Figure 5 This is a schematic diagram of the outer shell cross-section.

[0020] The reference numerals in the attached diagram represent: 1. Gantry; 11. Support leg; 12. Main beam; 13. Electric track; 2. Robotic arm; 21. First arm; 211. Electric bar; 22. Second arm; 23. Third arm; 3. Connecting rod; 4. Sandblasting assembly; 41. Nozzle; 42. Conveyor pipe; 43. Branch pipe; 5. Brake assembly; 51. Housing; 52. Brake pad; 53. Fixing ring. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are for illustrative purposes only and are not intended to limit the invention. It should be noted that this invention is already in the actual research and development stage.

[0022] Example 1 like Figures 1 to 5As shown, this embodiment includes a gantry frame 1, which includes a main beam 12. Both ends of the main beam 12 are connected to support legs 11 via electric rails 13. A robotic arm 2 is also mounted on the main beam 12 via an electric slide rail. The robotic arm 2 includes a drive unit and a first arm 21. An electric lever 211 is also mounted on the first arm 21, used to change the length of the first arm 21. In this embodiment, the drive unit is several drive motors. The first arm 21 is fixedly connected to the moving part of the electric slide rail by bolts. A second arm 22 is hinged to the bottom end of the first arm 21. The second arm 22 is T-shaped, and at least two third arms 23 are hinged to the second arm 22. The third arms 23 are connected to the connecting rod 3 by bolts. The mechanical arm 2 is fixedly connected, and the driving component is used to drive the first arm 21, the second arm 22, and the third arm 23 to rotate. The transmission motor is connected to the adjacent hinge point. The mechanical arm 2 is also equipped with a sandblasting assembly 4, which includes a storage assembly, a storage tank, an air compressor, and a sandblasting pressure tank. The storage tank and the air compressor are both connected to the input end of the sandblasting pressure tank. The storage assembly is used to store abrasive and pressurized gas. The storage assembly is connected to several nozzles 41 through a conveying pipe 42. The output end of the sandblasting pressure tank is connected to the input end of the conveying pipe 42. An abrasive valve is provided at the connection between the sandblasting pressure tank and the conveying pipe 42, and the output end of the sandblasting assembly 4 is located on the connecting rod 3. Above, that is, each of the nozzles 41 is fixedly connected to the adjacent connecting rods 3 by bolts. The sandblasting assembly 4 is used to spray abrasive onto the surface to be sandblasted. The robotic arm 2 is used to change the position and angle of the sandblasting assembly 4. The robotic arm 2 is also equipped with a data acquisition component, which is used to acquire the distance information from the output end of the sandblasting assembly 4 to the impact point between the abrasive and the surface to be sandblasted. The acquisition component includes a laser emitter and a laser detector, both of which are mounted on the connecting rod 3. The laser emitter is used to emit laser light towards the surface to be sandblasted, and the laser detector is used to receive the laser light reflected from the surface to be sandblasted. The control system obtains distance information based on the time between laser emission and reception.

[0023] It also includes a control system, which includes a controller. The laser emitter, laser detector, drive unit, and abrasive valve are all electrically connected to the controller. The controller is used to control the drive unit to move the connecting rod 3 to the sandblasting position and swing it along a set sandblasting angle. The controller is also used to control the abrasive valve and air compressor to work alternately with the laser emitter and laser detector. The distance information collected by the acquisition component in each continuous time period is used as a dataset, and the mean of each dataset is calculated. The similarity of any three datasets obtained within the same sandblasting angle is also calculated. When there are no three sets of datasets with similarity less than a set value at the same sandblasting position, the surface to be sandblasted does not have an inner corner. At this time, the robotic arm 2 is controlled to drive the connecting rod 3 to move synchronously, and the sandblasting assembly 4 is controlled to sandblast the surface to be sandblasted synchronously. If at least three sets of datasets with similarity less than a set value are found, then the surface to be sandblasted has an interior angle. The controller obtains the roughness of the surface to be sandblasted based on the size and distribution of the extreme points in the dataset. When the similarity between the roughness obtained in real time and the threshold is greater than the set maximum value, the controller controls the robotic arm 2 to change the distance between the output end of the sandblasting component 4 and the surface to be sandblasted, as well as the sandblasting angle, until the similarity between the roughness obtained in real time and the threshold is not greater than the set maximum value.

[0024] The specific implementation method is as follows: When using this solution, select the appropriate abrasive according to the sandblasting requirements and fill it into the storage tank. Then start the device. With the operation of the electric slide rail and electric bar 211, move part of the second arm 22 to the appropriate position and control the drive to adjust the angle between the first arm 21 and the second arm 22, and between the second arm 22 and the third arm 23, so that the nozzle 41 reaches the initial sandblasting position. Then, by controlling the operation of the drive, the second arm 22 or the third arm 23 drives the nozzle 41 to swing at an appropriate sandblasting angle.

[0025] During this process, the controller controls the sandblasting component 4 and the acquisition component to work alternately, and the duration of their alternation is the same. When the acquisition component is working, the laser emitter continuously emits laser light towards the surface to be sandblasted. The laser light is reflected by the surface to be sandblasted and enters the laser detector. The controller obtains the distance information between the nozzle 41 and the abrasive impact position based on the time between emission and reception, the known installation positions of the laser emitter and laser detector, and the installation position of the nozzle 41.

[0026] The rotation angle of the nozzle 41 can be obtained based on the working power of the drive component. Therefore, based on the working power of the drive component and the working node and duration of the abrasive valve, the abrasive valve and the acquisition component each work once within the same angle range during the back-and-forth swing of the nozzle 41, ensuring that the sandblasting is complete at that sandblasting angle.

[0027] In the above process, after the controller moves the connecting rod 3 to the sandblasting position by adjusting the operation of the drive component, it first controls the acquisition component to work so that the connecting rod 3 completes its first reciprocating swing. The distance information obtained by the controller through the laser detector comes from the area that has not been sandblasted. At this time, since there is no interference from abrasive, the distance information obtained is more accurate and reliable. The controller collects the distance information collected by the acquisition component during each continuous working time into a dataset and calculates the mean of each dataset. The mean of the dataset is used to represent the distance from the impact point of the abrasive on the surface to be sandblasted to the nozzle 41 in that area.

[0028] The following situations are often encountered during sandblasting: First, for planar sandblasting, during one unidirectional swing of the nozzle 41, the distance between the surface to be sandblasted and the nozzle 41 gradually decreases from a large value to a small value, reaching its minimum when the nozzle 41 is perpendicular to the surface, and then gradually increases thereafter. Second, for sandblasting surfaces with external corners (or convex corners), during one unidirectional swing of the nozzle 41, the distance between the surface to be sandblasted and the nozzle 41 also shows a trend of decreasing from a large value to a small value and then increasing again, reaching its minimum when the nozzle 41 is perpendicular to the external corner. Third, for sandblasting surfaces with internal corners, during one unidirectional swing of the nozzle 41, the distance between the nozzle 41 and the surface to be sandblasted initially decreases from a large value to a small value and then increases again, reaching its minimum when the nozzle 41 is perpendicular to the external corner. From large to small, when the nozzle 41 is perpendicular to one of the inner angle planes, the distance between the nozzle 41 and the surface to be sandblasted reaches its minimum. Subsequently, the distance between the nozzle 41 and the surface to be sandblasted increases and gradually approaches the inner angle. When the nozzle 41 is perpendicular to the inner angle and sandblasts towards another plane, the distance between the nozzle 41 and the surface to be sandblasted decreases and then gradually increases. In the above process, there are at least three positions on the surface to be sandblasted that are at the same distance from the nozzle 41. However, in the two cases mentioned above, there are often only two positions that are at the same distance from the nozzle 41. Therefore, the plane position of sandblasting can be determined by the distance between each position on the surface to be sandblasted and the nozzle 41 during the sandblasting process.

[0029] That is, after obtaining the distances between each position on the surface to be sandblasted and the nozzle 41, the similarity of the mean values ​​of any two datasets is first obtained using Euclidean distance, and after defining pairwise similarity, the three pairwise similarity values ​​are added together and then divided by three to obtain the final triplet similarity.

[0030] When there is no dataset where the similarity of the three sets of means is less than the set value, it can be determined that the surface to be sandblasted is a plane or has an external angle. In this case, during the sandblasting process, after the abrasive impacts the surface to be sandblasted, it bounces off the surface and is less likely to impact the adjacent plane again, thus affecting the sandblasting effect of the other planes. In this case, the conventional sandblasting scheme can be continued.

[0031] When a dataset with three sets of mean similarities less than a set value appears, it can be determined that the blasted surface has an inner angle. During the blasting process, after the abrasive impacts either side of the inner angle, it bounces off the plane and easily impacts the other side, subsequently bouncing alternately on both sides until the abrasive's kinetic energy is exhausted. In this process, the number of pits caused by a single abrasive jet on the blasted surface far exceeds that of a blasted surface without an inner angle. As a result, after blasting, the roughness of the blasted surface is greater than the required roughness. At this point, before the nozzle 41 performs its second reciprocating swing, the controller controls the drive unit to operate, driving the first arm 21 and the second arm 22. The combined movement of the third arm 23 increases the distance between the nozzle 41 and the surface to be blasted, thus reducing the kinetic energy of the abrasive as it travels from the nozzle 41 to the surface. Simultaneously, the angle between the nozzle 41 and the surface is adjusted to keep the angle relatively small, reducing the probability of the abrasive rebounding from one plane and impacting another. Furthermore, depending on the blasting requirements, when the surface roughness requirement is low, the rotation speed of the nozzle 41 can be increased to reduce the amount of abrasive impacting the surface per unit area, thereby offsetting the increased pitting caused by the rebound and reducing the impact of abrasive rebound on the surface roughness.

[0032] Simultaneously, during the aforementioned process, when it is determined that the surface to be sandblasted has an inner angle, the controller, based on the rotation angle of the nozzle 41 and the distance information corresponding to each angle, can acquire point cloud data of the straight line on the same plane as the laser emitter and laser detector within the sandblasting range after the nozzle 41 completes one reciprocating swing. By selecting any reference surface, the height deviation between the point cloud data and the reference surface is calculated, and the height deviation set is obtained, thus the roughness can be obtained. Since the sandblasting scheme in this solution adopts a small amount and multiple times, the nozzle 41 often needs to reciprocate several times during the sandblasting process. Since the material of the surface to be sandblasted, the abrasive, and the abrasive flow rate are known, it is possible to calculate the change in the roughness of the surface to be sandblasted after the nozzle 41 reciprocates once, and use this theoretical value as a threshold. That is, the threshold corresponding to each reciprocating swing is different and gradually increases.

[0033] Because sandblasting and data acquisition are performed alternately, with data acquisition preceding sandblasting, the controller can use the robotic arm 2 to adjust the position and angle of the nozzle 41 in the current reciprocating swing in a timely manner based on the roughness obtained from the previous reciprocating swing of the nozzle 41. This avoids the problem of excessive roughness caused by untimely adjustment, which would affect the sandblasting quality.

[0034] Compared to existing technologies, this solution has significant advantages when facing the support position of a T-beam. Through the coordinated work of the first arm 21, the second arm 22, and the third arm 23, the nozzle 41 can reach a position perpendicular to the planes on both sides of the support, performing sandblasting on the inner corner of the T-beam support position. During the process, adjustments are made in real time based on the sandblasting effect, reducing the difficulty in monitoring the sandblasting effect in existing technologies such as manual and machine sandblasting, which makes the sandblasting effect greatly affected by abrasive rebound. At the same time, compared to solutions using dedicated nozzles for inner corners, this solution does not require nozzle 41 replacement when facing planes or outer corners, reducing the sandblasting time per unit area and improving sandblasting efficiency. When facing the magnetic nozzle 41, this solution has low requirements for abrasives and can adapt to various metallic or non-metallic abrasives.

[0035] Compared to solutions that use baffles or guide sleeves to prevent the abrasive from bouncing off one plane to another, this solution fully utilizes the flexibility of the robotic arm 2. This allows the solution to adapt to the rotation of the nozzle 41 at different angles and heights during the sandblasting process, effectively avoiding the shadow area created by the baffle on the surface to be sandblasted on the ship, thus preventing uneven sandblasting. At the same time, this solution can also make full use of the abrasive's rebound, thereby achieving the same effect as traditional solutions with less abrasive on the surface to be sandblasted. The process results in less wear on the overall device, eliminates the need for frequent replacements after operation, and has low long-term costs, meeting the durability and economic requirements of sandblasting equipment for large-scale engineering projects such as shipbuilding.

[0036] Compared to solutions using machine vision, this solution utilizes smaller sensors that can be mounted at the end of the robotic arm 2 to collect data from confined spaces such as the T-shaped plate support area. Furthermore, the quality of the data collected is less affected by ambient lighting. When the robotic arm 2 and nozzle 41 operate within confined spaces like the support area, the resulting shadows have minimal impact on the data quality. Additionally, the intermittent sandblasting and data acquisition method reduces the obstruction of the sandblasted surface by the abrasive material during data acquisition, thus minimizing the impact of sandblasting on the data quality.

[0037] Example 2 The difference from the above embodiments is that a recovery component is also included. This recovery component is used to recover the abrasive that bounces off the surface to be blasted. The controller is also used to acquire blasting parameters input by the user. In this solution, the blasting parameters include air pressure, the material of the surface to be blasted, the required surface roughness (e.g., roughness), abrasive type, abrasive particle size, abrasive shape, spray gun moving speed, the initial angle between the nozzle 41 and the surface to be blasted, and the distance between the nozzle 41 and the surface to be blasted. The controller then adjusts the acquisition component and the blasting component 4 for each operation based on these blasting parameters. To adjust the duration and synchronize the operation of the acquisition component and the recovery component, in this embodiment, the recovery component includes a negative pressure pump and a sand suction pipe. The negative pressure pump is installed on the main beam 12, and the connecting rod 3 is provided with an input end of the sand suction pipe. The sand suction pipe is installed on the robotic arm 2, and the output end of the sand suction pipe is connected to a collection tank. The negative pressure pump is used to generate negative pressure in the sand suction pipe, and the sand suction pipe is used to transport the abrasive that bounces off the surface to be sandblasted. The controller controls the negative pressure pump to work simultaneously with the acquisition component.

[0038] The specific implementation method is as follows: When using this solution, the controller predicts the change in roughness on the surface to be sanded after the sandblasting component 4 has worked continuously once, based on the sandblasting parameters input by the user. That is, by changing the duration of continuous operation of the sandblasting component 4 and the rotation angle of the nozzle 41, the coverage area of ​​the abrasive and the roughness of the surface to be sanded are changed by the continuous operation of the sandblasting component 4.

[0039] At the same time, the negative pressure pump and the acquisition components (i.e., the laser emitter and the laser detector) work synchronously, which avoids the abrasive that has not yet impacted the surface to be sandblasted being attracted by the negative pressure pump during the sandblasting process, thus affecting the final sandblasting effect. In addition, due to the design of the negative pressure pump, this solution can effectively reduce the impact of abrasive rebound during the working time of the acquisition components on the laser, and thus affect the accuracy of the distance information.

[0040] Compared to existing technologies, this solution can recover abrasives during sandblasting operations, significantly reducing the working time required for sandblasting and abrasive recovery to be performed separately in traditional solutions, effectively improving sandblasting efficiency. At the same time, by performing sandblasting and abrasive recovery simultaneously, this solution further reduces the impact of abrasive rebound on sandblasting and data acquisition results.

[0041] Simultaneously, the recycling component can also be used to recycle and reuse abrasives. Operators can connect this device to the abrasive screening device to achieve the recycling of abrasives and effectively reduce the total amount of abrasive required during ship sandblasting.

[0042] Example 3 The difference from the above embodiment is that: it also includes a branch pipe 43, the input end of which is connected to the sandblasting pressure tank, the nozzle 41 is connected to the output end of the branch pipe 43, and the output end of the storage assembly is equipped with a solenoid valve, which is a solenoid three-way valve. The solenoid valve is used to change the pipeline connected to the sandblasting pressure tank. The control system also includes a communication module and several flow sensors. The communication module is used to send prompt information to the user, and the flow sensors are used to collect the flow rate at the input and output ends of the delivery pipe 42. The communication module, solenoid valve, flow sensors, and abrasive valve are all electrically connected to the controller. The controller is also used to calculate the flow rate difference between the input and output ends of the delivery pipe 42, and only when the flow rate difference is greater than a set value, it sends a prompt information to the user through the communication module, controls the solenoid valve to connect the branch pipe 43 to the storage assembly and close the connection between the delivery pipe 42 and the storage assembly.

[0043] The controller is also electrically connected to the sandblasting pressure tank. The controller is also used to adjust the robotic arm 2 according to the distance information after the branch pipe 43 is opened. When the roughness of the sandblasted surface is still uneven, the controller controls the material storage component to change the flow rate and pressure of the sprayed abrasive according to the roughness.

[0044] In this embodiment, the abrasive is made of magnetic material, and the recycling component includes a magnetic field generator. The magnetic field generator is used to change the magnetic field of the surface to be sandblasted. The magnetic field generator is electrically connected to a controller, and the controller is used to control the operation of the magnetic field generator according to the position of the impact point of the abrasive on the surface to be sandblasted.

[0045] The specific implementation method is as follows: When using this solution, as sandblasting proceeds, the controller continuously collects the flow rate at the input and output ends of the conveying pipe 42 based on the flow sensor. According to the change in flow rate, the kinetic energy loss of the abrasive during the flow process in the conveying pipe 42 can be obtained. When the flow rate difference between the input and output ends of the conveying pipe 42 is greater than the set value, the kinetic energy loss is large, which means that the conveying pipe 42 may be damaged or bent. The controller sends a prompt message to the user through the communication module and controls the solenoid valve to change the passage from the sandblasting pressure tank to the nozzle 41, so that the abrasive enters the nozzle 41 from the branch pipe 43, thereby avoiding sandblasting failure caused by damage or bending of the conveying pipe 42 during the sandblasting process.

[0046] Simultaneously, during the working gap of the sandblasting assembly 4, i.e. after the abrasive valve is closed, the flow rate at the input and output ends of the delivery pipe 42 is collected. If the delivery pipe 42 is in a normal state, when the abrasive inside the delivery pipe 42 reaches a stable state, the flow rate of the flow sensor will decrease until it approaches zero. When the delivery pipe 42 is damaged, the abrasive flows out of the delivery pipe 42 from the damaged position, causing the flow rate at both ends of the delivery pipe 42 to change. Based on the change in flow rate, the controller can check the state of the delivery pipe 42. When there is a large difference in flow rate between the input and output ends of the delivery pipe 42 during sandblasting, the controller can determine whether the change is caused by the damage to the delivery pipe 42 based on the change in flow rate during the working gap of the sandblasting assembly 4. At this time, the controller can also determine the relative position of the damaged position to both ends of the delivery pipe 42 based on the difference in flow rate on both sides, and send the above information to the user to prompt the user to carry out maintenance.

[0047] After the branch pipe 43 is opened, when the controller determines again that the surface to be sandblasted has uneven roughness based on the distance information, and the adjustment by the robotic arm 2 is ineffective, the branch pipe 43 is blocked or damaged. At this time, the controller controls the sandblasting pressure tank and other equipment to increase the flow rate and pressure of the abrasive to compensate for the energy loss caused by the blockage or damage of the branch pipe 43.

[0048] Meanwhile, the magnetic field generator selected for the recovery of magnetic materials in this solution has a faster and more efficient recovery speed for abrasives compared to the negative pressure pump in the previous embodiment.

[0049] Compared to existing technologies, this solution monitors the flow rate at both ends of the delivery pipe 42, enabling the identification of uneven sandblasting caused by blockages in the delivery pipe 42 during the sandblasting process, thus facilitating rapid repairs for users. Furthermore, the design of the branch pipe 43 allows for timely intervention in case of malfunctions in the delivery pipe 42, preventing increased operation time due to damage to the delivery pipe 42.

[0050] Example 4 The difference from the above embodiments is that a brake assembly 5 is also disclosed. The brake assembly 5 includes an annular outer shell 51, and a fixing ring 53 is provided inside the outer shell 51. The fixing ring 53 is made of an elastic material with a high elastic modulus. The fixing ring 53 is welded and fixed to the hinge point of the robotic arm 2, and the fixing ring 53 is eccentrically hinged to the outer shell 51. A plurality of brake pads 52 are welded and fixed to the inner sidewall of the outer shell 51. The brake pads 52 are evenly arranged around the axis of the outer shell 51. In the initial state (i.e., when the first arm 21 and the second arm 22 or the second arm 22 and the third arm 23 are in a relatively stable state), the brake pads 52 are in a martensitic state, and their length is the same as the longest distance between the outer sidewall of the fixing ring 53 and the inner sidewall of the outer shell 51. The brake pads 52 are all the same length, and all brake pads 52 are made of shape memory metal. In addition, the housing 51 is equipped with a pulse assembly, which is used to change the temperature of the brake pad 52. The pulse assembly consists of a battery (not shown in the figure) and a Hall current sensor (not shown in the figure). The battery is used to energize the brake pad 52, and the Hall current sensor is used to collect the current through the brake pad 52. The controller is connected to the Hall sensor and the battery. The controller is used to connect the battery to the brake pad 52 around the position where the distance between the outer wall of the fixing ring 53 and the inner wall of the housing 51 is the smallest according to the working time and power of the driving component, and synchronously control the Hall current sensor to work. According to the current magnitude information returned by the Hall current sensor, the controller keeps the current inside the brake pad 52 within a suitable range, thereby causing the brake pad 52 to transform from a martensitic state to an austenitic state.

[0051] The specific implementation method is as follows: During the implementation of this scheme, the controller cuts off the current to the battery and brake pad 52 when the drive component is working, based on the working state of the drive component. At this time, the brake pad 52 is in a martensitic state and is easily deformed. The controller can control the drive component to drive the robotic arm 2 to work, so that the hinge point between the first arm 21 and the second arm 22 or the second arm 22 and the third arm 23 pushes the brake pad 52 to deform through the fixing ring 53. As each hinge point rotates, the fixing ring 53 pushes the brake pad 52 to deform more intensely. The first arm 21 and the second arm 22 or the second arm 22 and the third arm 23 move from a relatively stable state to a relatively unstable state. At this time, if the controller stops the work of the drive component, the controller will adjust the current according to the initial state of the fixing ring 53, the working power of the drive component, and the operating status of the mechanical arm 2. The working time of the drive component can obtain the rotation angle of the hinge point fixedly connected to the fixed ring 53, thereby obtaining the real-time position of the point where the distance between the outer wall of the fixed ring 53 and the inner wall of the outer shell 51 is the minimum. Subsequently, the controller controls the connection between the battery and the brake pads 52 around this position, and controls the Hall current sensor to work to monitor and adjust the current of the connection, so that the brake pads 52 change from the martensitic state to the austenitic state. The brake pads 52 tend to reset and at the same time apply a pushing force to the fixed ring 53, compressing the fixed ring 53 to deform. Since the brake pads 52 are evenly distributed, the force applied to the fixed ring 53 during the reset process of the brake pads 52 can be symmetrically distributed along the axis of the fixed ring 53, avoiding the generation of torque on the fixed ring 53 during the reset process of the brake pads 52, which would affect the limiting effect.

[0052] Simultaneously, after the brake pad 52 returns to its austenitic state, when the hinge position of the robotic arm 2 shows a tendency to drive the fixed ring 53 to rotate, as the fixed ring 53 rotates to both sides, the point closest to the outer shell 51 gradually squeezes the surrounding brake pad 52, which has returned to its austenitic state. Due to the influence of the elasticity and size of the fixed ring 53, as the fixed ring 53 rotates, the resistance of the brake pad 52 to the fixed ring 53 gradually increases, thereby achieving step-by-step braking of the fixed ring 53. Compared with the transmission brake scheme, this scheme has less impact on the hinge position of the robotic arm 2, a lower probability of overshoot, and the wear of the brake pad 52 by the fixed ring 53 in this scheme is more uniform, which can avoid the instantaneous concentration of impact force and damage to key parts, thereby extending the service life of the brake.

[0053] In addition, this solution can also be implemented by adding an insulating fluid between the housing 51 and the fixed ring 53. The fluid can be used to insulate the fixed ring 53 and the brake pad 52, so as to prevent the brake pad 52 from breaking down the air inside the housing 51 when it is energized, thus affecting the effectiveness of the brake assembly 5.

[0054] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A gantry-type dual-arm robot for ship sandblasting, comprising a gantry frame (1), a robotic arm (2) mounted on the gantry frame (1), a plurality of connecting rods (3) fixedly connected to the robotic arm (2), a sandblasting assembly (4) also mounted on the robotic arm (2), and the output end of the sandblasting assembly (4) being disposed on the connecting rods (3), the sandblasting assembly (4) being used to spray abrasive onto the surface to be sandblasted, and the robotic arm (2) being used to change the position and angle of the sandblasting by the sandblasting assembly (4), characterized in that: The robotic arm (2) is also equipped with a data acquisition component, which is used to acquire the distance information from the output end of the sandblasting component (4) to the impact point between the abrasive and the surface to be sandblasted; It also includes a control system, which is used to control the robotic arm (2) to move the connecting rod (3) to the sandblasting position and swing along the set sandblasting angle. The control system is also used to control the sandblasting component (4) and the acquisition component to work alternately, take the distance information acquired by the acquisition component in each continuous time period as the dataset, calculate the mean of each dataset, and calculate the similarity of any three datasets obtained within the same sandblasting angle. Only when at least three sets of datasets with similarity less than a set value are found, it is determined that the surface to be sandblasted has an inner angle. The control system obtains the roughness of the surface to be sandblasted based on the size and distribution of the extreme points in the dataset. When the real-time roughness is more similar to the threshold than the set maximum value, the control system controls the robotic arm (2) to change the distance between the output end of the sandblasting component (4) and the surface to be sandblasted, as well as the sandblasting angle, until the real-time roughness is no more similar to the threshold than the set maximum value. It also includes a brake assembly (5), which includes an annular outer shell (51). The outer shell (51) has a fixing ring (53) inside, which is made of elastic material. The fixing ring (53) is fixedly connected to the hinge point of the robotic arm (2), and the fixing ring (53) is eccentrically hinged to the outer shell (51). The inner sidewall of the outer shell (51) is provided with a plurality of brake pads (52). The brake pads (52) are of the same length and are evenly arranged around the axis of the outer shell (51). The brake pads (52) are all made of shape memory metal. The outer shell (51) also has a pulse assembly, which is used to change the temperature of the brake pads (52). The control system is used to control the pulse assembly to work in the working state of the robotic arm (2).

2. The gantry-type dual-arm robot for ship sandblasting according to claim 1, characterized in that: The robotic arm (2) includes a drive unit and a first arm (21). The top of the first arm (21) is mounted on the gantry frame (1). The bottom of the first arm (21) is hinged to a second arm (22). Several third arms (23) are hinged to the second arm (22). The connecting rod (3) is hinged to the side wall of the third arm (23). The drive unit is used to drive the first arm (21), the second arm (22) and the third arm (23) to rotate. The control system controls the operation of the drive unit according to the distance information.

3. A gantry-type dual-arm robot for ship sandblasting according to claim 1, characterized in that: The acquisition component includes a laser emitter and a laser detector. The laser emitter is used to emit laser light towards the surface to be sandblasted, and the laser detector is used to receive the laser light reflected from the surface to be sandblasted. The control system obtains distance information based on the time between laser emission and reception.

4. A gantry-type dual-arm robot for ship sandblasting according to claim 1, characterized in that: It also includes a recovery component for recovering abrasive that bounces off the surface to be blasted. The control system is also used to acquire blasting parameters input by the user, adjust the duration of a single operation of the acquisition component based on the blasting parameters, and synchronize the acquisition component with the recovery component.

5. A gantry-type dual-arm robot for ship sandblasting according to claim 4, characterized in that: The sandblasting assembly (4) includes a storage assembly for storing abrasive and pressurized gas. The storage assembly is connected to several nozzles (41) through a conveying pipe (42). An abrasive valve is provided at the connection between the storage assembly and the conveying pipe (42). The nozzles (41) are all fixedly connected to the adjacent connecting rods (3). The control system controls the operation of the abrasive valve and the storage assembly according to the distance information.

6. A gantry-type dual-arm robot for ship sandblasting according to claim 5, characterized in that: It also includes a branch pipe (43), the input end of which is connected to the storage component, the nozzle (41) is connected to the output end of the branch pipe (43), the output end of the storage component is provided with a solenoid valve, the solenoid valve is used to change the pipe connected to the storage component, the control system is also used to collect the flow rate at the input and output ends of the delivery pipe (42), the control system is also used to calculate the flow rate difference between the input and output ends of the delivery pipe (42), and only when the flow rate difference is greater than a set value, it sends a prompt message to the user and controls the solenoid valve to connect the branch pipe (43) to the storage component and close the connection between the delivery pipe (42) and the storage component.

7. A gantry-type dual-arm robot for ship sandblasting according to claim 6, characterized in that: The control system is also used to adjust the robotic arm (2) according to the distance information after the branch pipe (43) is opened, and when the roughness of the sandblasted surface is still uneven, to control the material storage component to change the flow rate and pressure of the sprayed abrasive according to the roughness.

8. A gantry-type dual-arm robot for ship sandblasting according to claim 7, characterized in that: The recycling component includes a negative pressure pump and a sand suction pipe. The sand suction pipe is installed on the robotic arm (2). The output end of the sand suction pipe is connected to a collection tank. The negative pressure pump is used to generate negative pressure in the sand suction pipe. The sand suction pipe is used to collect the abrasive material that bounces off the surface to be sandblasted. The control system is also used to control the negative pressure pump to work while the collection component is working.

9. A gantry-type dual-arm robot for ship sandblasting according to claim 7, characterized in that: The abrasive is made of magnetic material, the recycling component includes a magnetic field generator, the magnetic field generator is used to change the magnetic field of the surface to be sandblasted, and the control system is used to control the operation of the magnetic field generator according to the position of the impact point of the abrasive on the surface to be sandblasted.

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