Method for repairing defects in plywood

Abstract

The present application relates to the technical field of plywood repair, in particular to a plywood defect repairing method, which comprises (1) a detection module collects defect data of the plywood entering a data collection area to obtain plywood defect data and sends the plywood defect data to a control module; (2) the control module receives the plywood defect data and calls an analysis module to plan an optimal repairing path according to the plywood defect data and the current state of the execution module to obtain the optimal repairing path and feed back the optimal repairing path to the control module; (3) the control module sends the received optimal repairing path to an execution module, and the execution module repairs defects of the corresponding plywood entering a repairing area. The method can greatly reduce labor costs, speed up repairing efficiency, ensure workpiece quality and improve company profits.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plywood repair, in particular to a plywood defect repair method. BACKGROUND

[0002] The plywood defect repair function has been an important but neglected problem in the field of wood repair. At present, most domestic manufacturers still repair plywood defects manually. Although manual methods can ensure that defects are completely repaired, this method has the disadvantages of high labor cost and low repair efficiency.

[0003] In the specification of the invention patent CN201980059436.9, a plywood repair solution is disclosed. This solution uses a detection device to perform a scanning operation on the plywood, and stops the movement of the plywood based on the information obtained by the detection device to perform a repair operation using a repair device.

[0004] The existing plywood repair function on the market is mostly to stop the plywood after detecting the defect, and use a repair device to repair the defect, focusing on defect repair and ignoring processing efficiency.

[0005] Therefore, there is an urgent need for a new technical solution to solve the above technical problems. SUMMARY

[0006] The present application aims to overcome the problems of the prior art and provides a plywood defect repair method. The method uses a vision camera to take pictures to obtain defects such as cracks and holes on the plywood. According to the user-set conveying belt movement speed, the optimal trajectory connecting all defects is planned while the plywood is moving with the conveying belt. Multiple robots are used to repair the defects on the plywood in the shortest time, thereby solving the problems of low repair quality and low efficiency in traditional repair technology.

[0007] The above-mentioned object is achieved by the following technical solution:

[0008] A plywood defect repair method includes a feeding conveying belt, a repair area and a data acquisition area are arranged in sequence along the advancing direction of the feeding conveying belt, the data acquisition area is provided with a monitoring module, the repair area is provided with an execution module, the monitoring module and the execution module are connected with a control module respectively, and an analysis module is further arranged in the control module; the method includes the following steps:

[0009] Step (1) Defect data acquisition At least one plywood is conveyed on the feeding conveying belt, the monitoring module acquires defect data of the plywood entering the data acquisition area, obtains plywood defect data, and sends the plywood defect data to the control module.

[0010] Step (2) repair path planning The control module receives the plywood defect data, and calls the analysis module to perform optimal repair path planning according to the plywood defect data and the current state of the execution module, to obtain an optimal repair path, and feeds back the optimal repair path to the control module.

[0011] Step (3) defect site repair The control module sends the received optimal repair path to the execution module, and the execution module performs defect repair on the corresponding plywood in the repair area.

[0012] Further, a repair area approach switch and a collection area approach switch for sensing the entering state of the plywood are arranged at the entrance of the repair area and the data collection area respectively; the repair area approach switch and the collection area approach switch are in communication with the control module.

[0013] Further, the detection module is a vision camera distributedly installed in the data collection area, and each vision camera is connected with a vision processing unit, which can take photos and analyze and detect the defect site of the plywood entering the data collection area to obtain plywood defect data.

[0014] Further, the execution module is at least one mechanical hand installed in the repair area, which is used to receive the work instruction issued by the control module and perform defect repair on the plywood entering the repair area.

[0015] Further, the control module is an upper computer.

[0016] Further, the optimal repair path planning in step (2) specifically includes the following steps:

[0017] Step (a) calculate the minimum time length and the maximum time length that can be moved within the range of the mechanical hand according to all defect points that need to be planned;

[0018] Step (b) calculate the minimum time length of each defect to obtain the shortest time to plan the initial path;

[0019] Step (c) use the movement speed of the mechanical hand and the corresponding acceleration and deceleration parameters to calculate the movement time between each defect in the planned initial path, and compare it with the minimum time length and the maximum time length of each defect;

[0020] If the time to reach the target defect in the planned path exceeds the range of the minimum time length and the maximum time length, the defect cannot meet the requirements, and the defect is removed;

[0021] Step (d) detects whether all the remaining defects can be inserted into the initial trajectory based on cross variation;

[0022] Step (e) repeatedly steps (a)-(d) to continuously add new defects to the planned path and judge whether the added defects meet the constraint conditions, and if so, the defects are retained, and if not, the defects are removed.

[0023] Further, the minimum time length in step (a) is the start time when the defect just enters the range of the manipulator, and the maximum time length is the end time when the defect just leaves the range of the manipulator. If the defect is within the range of the manipulator within the minimum time length and the maximum time length, the defect can be repaired. Advantages

[0024] The plywood defect repairing method provided by the application plans trajectories for defects on the plywood without stopping the plywood, connects the defects together through optimal trajectories, and uses multiple manipulators to repair the plywood, which can effectively enhance the coordination ability of the entire system, greatly reduce labor costs, speed up the repairing efficiency, ensure the quality of workpieces, and improve the company's revenue. In addition, the method has the following advantages:

[0025] 1. When the manipulator repairs defects on the plywood, the plywood can move with the conveyor belt without stopping, i.e., the manipulator can move back and forth within a limited range to repair the entire plywood, which shortens the length of the entire production line and improves the application range of the product equipment.

[0026] 2. Multiple manipulators can work together, and the defects on the plywood are divided into multiple types and repaired by different manipulators in specific modes, which can save the use of paint.

[0027] 3. The system provided in the method has high defect repairing efficiency and small error, and can accurately repair corresponding defects even when the conveyor belt is moving at high speed.

[0028] 4. The entire system is divided into four modules, each module has its own function and is not disturbed by other modules, and the maintenance, upgrade and replacement of each module will not affect other modules. Developers can develop the functions of the four modules separately to speed up the updating efficiency of the product and greatly improve the stability of the system.

[0029] 5. Through the analysis module, the defect data on the plywood is planned for trajectory planning of multiple manipulators according to customer requirements, and the calculation of the optimal path can be completed within 0.5s.

[0030] 6. Users only need to control the operation of the other three modules through the control module (i.e., the upper computer), which reduces the overall use difficulty. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 A plywood defect repairing method flow chart is provided in the present application;

[0032] Figure 2 A system structure in the plywood defect repairing method is provided in the present application;

[0033] Figure 3 A detection module working schematic diagram in the plywood defect repairing method is provided in the present application;

[0034] Figure 4 An analysis module analysis flow chart in the plywood defect repairing method is provided in the present application;

[0035] Figure 5 An execution module execution flow chart in the plywood defect repairing method is provided in the present application;

[0036] Figure 6 A control module control flow chart in the plywood defect repairing method is provided in the present application. DETAILED DESCRIPTION

[0037] The present application will be further described in detail below according to the drawings and embodiments. The described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts fall within the scope of protection of the present application.

[0038] As shown in Figure 1 and 2 , a plywood defect repairing method comprises a feeding conveyor belt, a repairing area and a data acquisition area are sequentially arranged along the advancing direction of the feeding conveyor belt, the data acquisition area is provided with a monitoring module, the repairing area is provided with an execution module, the monitoring module and the execution module are respectively connected with a control module, and an analysis module is further arranged in the control module; comprising the following steps:

[0039] Step (1) defect data acquisition: at least one plywood is conveyed on the feeding conveyor belt, the monitoring module acquires defect data of the plywood entering the data acquisition area, obtains plywood defect data, and sends the plywood defect data to the control module;

[0040] Step (2) repairing path planning: the control module receives the plywood defect data, calls the analysis module to plan an optimal repairing path according to the plywood defect data and the current state of the execution module, obtains the optimal repairing path, and feeds back the optimal repairing path to the control module;

[0041] Step (3) Defect site repair The control module sends the received optimal repair path to the execution module, and the execution module performs defect repair on the corresponding plywood in the repair area.

[0042] As a description of the system provided in this embodiment: including a feeding conveyor belt, a repair area and a data acquisition area are sequentially arranged along the advancing direction of the feeding conveyor belt, the data acquisition area is provided with a monitoring module, the repair area is provided with an execution module, the detection module and the execution module are connected with a control module respectively, and an analysis module is further arranged in the control module; A repair area proximity switch and a collection area proximity switch for sensing the entering state of the plywood are arranged at the entering end of the repair area and the data acquisition area respectively; The repair area proximity switch and the collection area proximity switch are in communication with the control module respectively;

[0043] As shown in Figure 3 The detection module is a vision camera distributedly installed in the data acquisition area, each vision camera is connected with a vision processing unit, can take photos and analyze and detect the defect site of the plywood entering the data acquisition area, acquire plywood defect data, and send the plywood defect data to the control module for processing.

[0044] Specifically, the plywood follows the feeding conveyor belt to advance, is sensed by the collection area proximity switch before entering the data acquisition area (the range of camera detection), and feeds back a signal to the host control module, the host control module sends a data acquisition instruction to the detection module (vision camera), the vision camera works, and detects the defects of the plywood entering the data acquisition area. After the plywood leaves the scanning range of the vision camera, the internal part of the vision camera starts to process the defect data, and after the processing is completed, the data is sent to the control module.

[0045] As shown in Figure 4 The analysis module is used only for optimal trajectory planning operation of multiple robots according to the defect data sent by the detection module and corresponding external parameters (such as plywood movement speed, current position of the robot, etc.), and then sends the planned optimal trajectory data to the control module.

[0046] Specifically, the detection module sends the defect data to the control module, the control module acquires the template defect data and calls the analysis module to prepare to analyze the data, the control module transmits relevant parameters into the analysis module, the analysis module calls the defect data and robot parameters, uses a trajectory planning algorithm to arrange an optimal path connecting all defects, and returns the planned path to the control module.

[0047] As shown in Figure 5As shown, the execution module is at least one mechanical hand installed in the repairing area, used to receive the work instruction issued by the control module, repair the defects of the plywood entering the repairing area, and send different signals to the master control module when moving to the corresponding position.

[0048] Specifically, there is a distance between the plywood leaving the visual camera range (data acquisition area) and the mechanical hand (repairing area), which is the time required for the visual camera to send data to the control module, the control module to call the analysis module to analyze the data, and the data to be downloaded to the execution module after being prepared; before the plywood continues to advance to the repairing area, it is sensed by the repairing area proximity switch, at which time the execution module receives the control module signal and data, and judges whether the data is issued within the specified time according to the signal; if not, the mechanical hand skips this plywood; if yes, it is judged according to the data whether the template needs to be repaired, if yes, the mechanical hand moves and starts repairing the plywood defects according to the issued data; if not, the mechanical hand skips this plywood.

[0049] As shown in Figure 6 The control module is a host computer, which is the core of the system, needs to receive information from other modules, processes it internally, and then controls the corresponding modules to perform different operations.

[0050] Specifically, it includes the following steps:

[0051] Step 1.1. Issue a start signal to start the conveyor belt;

[0052] Step 1.2. When the plywood triggers the acquisition area proximity switch, the control module receives the corresponding signal and starts the detection module, and the visual camera starts scanning the plywood defects;

[0053] Step 1.3. After the camera scans the plywood defects, the visual data is sent to the control module, and the control module obtains the visual data and calls the analysis module; before the analysis module plans the trajectory, it obtains data such as conveyor belt parameters and mechanical hand position;

[0054] Step 1.4. Read the configuration parameters of the execution module and transfer them to the analysis module to start planning the optimal path; during trajectory planning, the signal of the execution module needs to be monitored at all times;

[0055] Step 1.5. Monitor the real-time position of the plywood in the execution module, and send a signal to the control module to perform the corresponding operation when the plywood moves into the mechanical hand area;

[0056] Step 1.6. Issue the optimal trajectory data in the analysis module, and the execution module judges whether the issued data is timely or normal to perform the corresponding operation;

[0057] Step 1.7. Controlling the movement of the mechanical arm to repair the defect; after the defect is repaired, the wood board leaves the conveyor belt;

[0058] Step 1.8. Repeating steps 1.2-1.7 until all defects of the plywood are repaired.

[0059] As a specific embodiment of the present embodiment

[0060] The path planning in Changxing door plate repair is planned based on genetic algorithm (GA), but the path planning has strict constraints on time (the trajectory needs to be calculated within 0.5 seconds), and the traditional GA is difficult to give reasonable output within the specified time, so a greedy solving idea is added for speed optimization.

[0061] Through this method, the stability of the GA solution is improved, and the solving speed of the algorithm is greatly improved, which can meet the industrial demand and make the solving time meet the time constraint (0.5 seconds);

[0062] The greedy solving step is described as follows:

[0063] That is, the optimal repair path planning in step (2) of the present embodiment specifically includes the following steps:

[0064] Step (a) calculates the minimum time length and maximum time length that can be moved within the range of the mechanical arm according to all defect points that need to be planned;

[0065] Step (b) accumulatively calculates the minimum time length of each defect to obtain the shortest time to plan the initial path;

[0066] Step (c) uses the movement speed of the mechanical arm and the corresponding acceleration and deceleration parameters to calculate the movement time between each defect in the planned initial path, and compares it with the minimum time length and maximum time length of each defect;

[0067] If the time to reach the target defect in the planned path exceeds the range of the minimum time length and the maximum time length, the defect cannot meet the demand, and the defect is removed;

[0068] Step (d) detects whether all remaining defects can be inserted into the initial trajectory based on crossover and mutation;

[0069] Step (e) repeats steps (a)-(d), continuously adds new defects to the planned path, and then judges whether the added defects can meet the constraint condition, if yes, the defects are retained, if not, the defects are removed.

[0070] Wherein, the minimum time length in step (a) is the start time when the defect just enters the range of the manipulator; the maximum time length is the end time when the defect just leaves the range of the manipulator; within the range of the minimum time length and the maximum time length, the defect is in the range of the manipulator, and the repairing can be performed, otherwise, once the defect (enters) / (leaves) the range of the manipulator, the defect cannot be repaired due to hardware reasons.

[0071] As shown in the figure, the embodiment needs to repair a piece of plywood, and the specific process of the wood board is as follows: Figure 2

[0072] 1. Defect data acquisition

[0073] When the wood board moves on the conveyor belt, after passing through the detection point proximity switch, the conveyor belt sends a plywood to the vision position signal to the upper computer.

[0074] After the upper computer receives the signal, the vision camera is immediately turned on to scan the defects on the wood board. After the scanning of this wood board is completed, the camera will perform simple processing on the scanning data, and then send the data to the control module (in this embodiment, the upper computer). (Note: After the current piece of wood board leaves the vision scanning area, the next piece of wood board can enter the vision scanning area again for scanning of the next piece of wood board, without the need for waiting)

[0075] 2. Repair path planning

[0076] After the wood board leaves the camera scanning, the wood board will move to the manipulator area. During the movement, the control module (in this embodiment, the upper computer) will call the analysis module to process the vision defect data, and plan the trajectory according to the way of repairing defects by multiple manipulators. After the path planning is completed, the trajectory data will be saved in the upper computer, ready to be sent to the manipulator.

[0077] In the trajectory planning process, it needs to be considered that: assuming that the length and width of the wood board are both 1200mm, the conveyor belt speed is 200mm / s, and the manipulator stroke range is 600mm, the maximum speed of the manipulator is 1600mm / s, and the defect data on the wood board is 100 defects.

[0078] We can calculate that the minimum time of the wood board in the range of the manipulator is (600 / 200 = 3s), and the maximum time is ((1200 + 600) / 200 = 9s), that is, no matter what defect, the wood board will leave the manipulator area after 9s, and cannot be repaired, therefore, we need to consider repairing enough defects within the maximum time of 9s.

[0079] ​Since the conveying belt speed is 200 mm / s, a single manipulator cannot complete all the repairing, so multiple manipulators are needed to complete the repairing.

[0080] 3. Defect position repairing

[0081] When the wood board moves into the manipulator area, the trajectory data is sent from the upper computer to the manipulator, and the manipulator moves according to the sent data to complete the repairing of all the defects on the wood board (multiple manipulators are needed to repair the same wood board in turn)

[0082] The above merely illustrates the embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of repairing defects in a plywood panel, characterized by, The feeding conveyor belt drives the plywood to move with the conveyor belt without stopping, and a repair area and a data acquisition area are sequentially arranged in the advancing direction of the feeding conveyor belt, the data acquisition area is provided with a monitoring module, the repair area is provided with an execution module, the execution module is at least one mechanical hand installed in the repair area, used for receiving the work instruction issued by the control module, and repairing the defects of the plywood entering the repair area; a plurality of mechanical hands can work together, and the defects of the plywood are divided into a plurality of types and handed over to different mechanical hands for specific mode repair, the detection module and the execution module are connected with the control module respectively, and an analysis module is further arranged in the control module; a repair area proximity switch and an acquisition area proximity switch for sensing the entering state of the plywood are arranged at the entering end of the repair area and the data acquisition area respectively; the repair area proximity switch and the acquisition area proximity switch are in communication with the control module respectively; the method comprises the following steps: Step (1) defect data acquisition: at least one plywood is conveyed on the feeding conveyor belt, the plywood advances with the feeding conveyor belt, is sensed by the acquisition area proximity switch before entering the data acquisition area, and feeds back a signal to the main control module; the main control module sends a data acquisition instruction to the detection module; the visual camera works, detects the defects of the plywood entering the data acquisition area, the detection module acquires the defect data of the plywood entering the data acquisition area, obtains the defect data of the plywood, and sends the defect data of the plywood to the control module; Step (2) repair path planning: the control module receives the defect data of the plywood, calls the analysis module to plan the optimal repair path according to the defect data of the plywood and the current state of the execution module, and calculates the minimum time length and the maximum time length of the movement of each defect within the range of the mechanical hand, wherein the minimum time length is the start time when the defect just enters the range of the mechanical hand; the maximum time length is the end time when the defect just leaves the range of the mechanical hand; if the defect is within the range of the mechanical hand within the minimum time length and the maximum time length, the defect can be repaired, the optimal repair path is obtained, and the optimal repair path is fed back to the control module; Step (3) defect site repair: the control module sends the received optimal repair path to the execution module, the plywood continues to advance to the repair area before the repair area proximity switch senses it, at this time, the execution module receives the signal and data of the control module, and judges whether the data is issued within the specified time according to the signal; if not, the mechanical hand skips this plywood; if yes, it is judged according to the data whether the template needs to be repaired; if yes, the mechanical hand moves and starts repairing the defect of the plywood according to the issued data; if not, the mechanical hand skips this plywood, and the execution module repairs the defects of the corresponding plywood entering the repair area.

2. The method of claim 1, wherein the method further comprises: The detection module is a visual camera distributedly arranged in the data acquisition area, each visual camera is connected with a visual processing unit, can take photos and analyze and detect the defect positions of the plywood entering the data acquisition area, and obtains plywood defect data.

3. The method of claim 1, wherein the method further comprises: The control module is an upper computer.

4. The method of claim 1, wherein the method further comprises: The optimal repair path planning in step (2) specifically includes the following steps. Step (a) calculates the minimum time length and the maximum time length capable of moving within the range of the manipulator according to all defect points needing to be planned; Step (b) accumulatively calculates the minimum time length of each defect to obtain the shortest time to plan an initial path; Step (c) uses the movement speed of the manipulator and corresponding acceleration and deceleration parameters to calculate the movement time between each defect in the planned initial path, and compares the movement time with the minimum time length and the maximum time length of each defect; If the time to reach the target defect in the planned path exceeds the range of the minimum time length and the maximum time length, the defect cannot meet the requirement, and the defect is removed; Step (d) detects whether all the remaining defects can be inserted into the initial trajectory based on crossover and mutation; Step (e) repeatedly performs steps (a) to (d), continuously adds new defects to the planned path, and judges whether the added defects can meet the constraint condition, if yes, the defects are retained, and if not, the defects are removed.

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