Patent Publication Number: US-2023146424-A1

Title: Automatic cement plastering and rendering system and operation method thereof

Description:
TECHNICAL FIELD 
     The present invention relates to a cement plastering and rendering system and its operation method, especially an automatic cement plastering and rendering system and operation method thereof in cooperation with a robot. 
     BACKGROUND OF RELATED ARTS 
     In the general cement plastering and rendering method, the main manner is to coat a layer of cement material on the wall to be constructed and use a tool (such as a trowel) to scrape the cement material to make it level before the cement material is dry. However, if the irregular gaps (or openings) on the wall are not filled with the cement material during coating and scraping, the unmodified gaps will appear concave after the cement material dries, such that the wall is difficult to level, which affects the appearance of the finished product. 
     However, it is common to use construction methods to solve this problem, the current methods are not only time-consuming and labor-intensive, but also heavily depend on the skill of the solid plasterer. In this regard, how to make the wall appear even in an automated and fast state is substantially what the industry requires. 
     SUMMARY 
     In order to solve at least one of the above-mentioned problems, some embodiments of the present invention provide a cement plastering and rendering system and an operation method thereof, especially an automatic cement plastering and rendering system and an operation method that cooperate with a robot. Specifically, the automatic cement plastering and rendering system utilizes the coordinate transformation of point cloud coordinates in different coordinate systems to control the actions of the slurry supply apparatus and robot during the spraying and finish of cement materials, so as to perform a plastering more effectively over a large area of wall, and thus the working hours are greatly shortened. 
     At least one embodiment of the present invention is an automatic cement plastering and rendering system configured in a machine with a slurry supply apparatus and a robot. The system includes at least one image capture device, a storage and a processor. The processor is connected to the image capture device and the storage and thus to realize the communication of the connection between the machine and the processor. 
     At least one embodiment of the present invention is an operation method of an automatic cement plastering and rendering system. The operation method comprises the following steps: provide the previously mentioned automatic cement plastering and rendering system. Produce a plurality of point cloud coordinates in the first coordinate system according to the at least one image acquired by the at least one image capture device. Perform coordinate transformation on the point cloud coordinates according to the at least one transfer matrix, so that the point cloud coordinates are transformed from the first coordinate system corresponding to the at least one image to the second coordinate system corresponding to the slurry supply apparatus, and again transform the point cloud coordinates from the second coordinate system corresponding to the slurry supply apparatus to the third coordinate system corresponding to the robot according to the at least one transfer matrix, and individually store the second coordinate system and the third coordinate system comprising the point cloud coordinates respectively. Control movement of the slurry supply apparatus according to the second coordinate system in the storage, so that the slurry supply apparatus is used to perform the spraying on the wall as a nozzle of the slurry supply apparatus is at a certain distance from the wall. Moreover, following the spraying, control movement of the robot according to the third coordinate system of the storage, so that the tool performs a plastering or rendering on the wall based on a predetermined path. 
     Embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates a schematic diagram of the automatic cement plastering and rendering system of the present invention. 
         FIG.  2    illustrates a flow chart of the operation method of the automatic cement plastering and rendering system of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In order to understand the technical features and practical efficacy of the present invention and to implement it in accordance with the contents of the specification, hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
     At least one embodiment of the present invention relates to a cement plastering system and its operating method thereof, especially an automatic cement plastering and rendering system that cooperates with a robot and its operating method. 
       FIG.  1    is a schematic diagram of the automatic cement plastering and rendering system of the present invention. In  FIG.  1   , the automatic cement plastering and rendering system  1  includes at least one image capture device  10 , a storage  11 , and a processor  12 , and the processor  12  is connected to the image capture device  10  and the storage  11 , so that a plurality of point cloud coordinates can be obtained by the image capture device  10  and processed by the processor  12 . 
     The automatic cement plastering and rendering system  1  is configured in a machine  2 . The machine  2  is equipped with at least a robot  21  and a slurry supply apparatus  20  and is connected to the processor  12  through communication. In this embodiment, the robot  21  may include any kind of machine elements or the like and may be connected to operating equipment such as an arm, a nozzle  201 , a sprayer, or a combination thereof as appropriate. In one aspect (please refer to  FIG.  1   ), the robot  21  can be a robotic arm, which has at least one upper arm  211 , at least one lower arm  212 , and a retainer  213 . The upper arm is configured at one end of the lower arm and mounted with at least one tool  214 . Otherwise, the retainer  213  is configured at the other end of the lower arm  212  to connect with the machine  2 . In this case, the at least one tool  214  can be a workpiece such as a trowel (spatula) or the like, which can be controlled by the robot  21  with a robot arm. 
     In this embodiment, the slurry supply apparatus  20  may also be any device used in spraying application to spray the cement material toward a wall  3  through a nozzle  201  provided therein (i.e., by using a S-shaped filling method for spraying). 
     The feature of this embodiment is that by establishing a coordinate transformation relation between a first coordinate system of the image capture device  10 , a second coordinate system of the slurry supply apparatus  20 , and a third coordinate system of the robot  21  (i.e., the coordinates of a certain feature in one coordinate system are converted to the coordinates of another coordinate system) to conduct the spraying as well as the plastering and rendering of the wall  3 . 
     Specifically, in this embodiment, it is assumed that the first coordinate system is an orthogonal coordinate system with the image capture device  10  as the origin, and the second coordinate system is an orthogonal coordinate system with the nozzle  201  of the slurry supply apparatus  20  as the origin, and the third coordinate system is an orthogonal coordinate system with tool  214  of robot  21  as the origin. Since the positional relationship of the image capture device  10 , the nozzle  201  and the tool  214  is fixed, the coordinate transformation from the first coordinate system to the second coordinate system and the second coordinate system to the third coordinate system can be controlled with higher precision. And, under this assumption, the image capture device  10  can be configured on the slurry supply apparatus  20  or on a location other than the slurry supply apparatus  20  and execute the coordinate transformation of multiple point cloud coordinates in the first coordinate system by using at least one transfer matrix stored in the storage  11 . 
     The image capture device  10  of  FIG.  1    may be a color camera or a gray scale camera coupled with a depth sensor, which is configured to capture at least one image in a scene and a plurality of depths. Specifically, the scene includes at least two border lines that allow the processor  12  to recognize the size of the wall  3 . Therefore, when generating a plurality of point cloud coordinates, the processor  12  can: determine a plurality of pixel coordinates in the image; input the depth into the pixel coordinates and perform matching to obtain a plurality of point cloud coordinates in the first coordinate system. Certainly, the image capture device  10  may also be a depth camera such as a time-of-flight (ToF) depth camera, an RGB-D camera, and a structured light three-dimensional scanning camera, which is not limited by the present invention. 
     Storage  11  can store information of processor  12  during operation or programs and functions during execution. In this embodiment, storage  11  can be configured to store and provide any type of long-term memory, short-term memory, long-term short-term memory (LSTM), volatile memory, non-volatile memory, or any computer-readable media of the image and the transfer matrix. The transfer matrix records the coordinate transformation relation between the first coordinate system and the second coordinate system, as well as the second coordinate system and the third coordinate system. In one aspect, storage  11  may be a part of the processor  12 , but it should be noted that the storage  11  may also be independent of the processor  12 . 
     The processor  12  may be a conventional processor used by people in the field, including a central processor (Central Processing Unit, CPU), a digital signal processor (Digital Signal Processor, DSP), a microprocessor (Micro Processing Unit, MPU), a microcontroller (Micro Control Unit, MCU) and its combination, etc. 
       FIG.  2    is a flowchart showing the operation method of the automatic cement plastering and rendering system  1  of the present invention. In this embodiment, first, the processor  12  controls the image capture device  10  to capture an image containing at least two border lines from the scene and generate the plurality of point cloud coordinates according to the image (step S 2 ). Afterwards, the processor  12  controls the movement of the slurry supply apparatus  20  so that the nozzle  201  is positioned at a certain distance in front of the wall  3  and allows the slurry supply apparatus  20  to move while determining the position of the wall  3  coordinates in the second coordinate system and the third coordinate system (step S 3 ). Under the abovementioned condition, the supply apparatus  20  performs a spraying action to cover the cement material on the wall  3  (step S 4 ) and stops the spraying action when it is determined that the predetermined time has passed (or the predetermined supply amount has been reached). Next, by positioning the tool  214  of the robot  21  in front of the wall  3 , the tool  214  performs plastering and rendering on the wall  3  along a predetermined path as shown in  FIG.  3    to generate a flat wall  3  (step S 5 ). As shown in  FIG.  2   , these steps can also be repeated until the entire wall  3  is painted. 
     The value of said certain distance in front of the wall  3  can be set according to the requirements, and the present invention is not limited. (For instance, if you want to spray a larger area of wall  3 , you can set a larger value.) 
     Preferably, in order to accurately fill the uneven parts of wall  3  (e.g., dents or bulges), the preceding process from spraying action to plastering and rendering or the process of solely plastering and rendering is preferably performed multiple times so that the wall  3  becomes more leveled. In detail, after step S 3  ends, the processor  12  can then determine whether there is at least one identifiable target coordinate in the wall  3  coordinates of the second coordinate system. In addition, when the result of the determination is “Yes”, the specific target coordinates are marked and recorded to indicate the uneven parts of the wall  3  that requires to be repeatedly executed step S 4 , or else, step S 4  and step S 5  thereon. For example, if the processor  12  recognizes that the distance value from a point cloud coordinate to the nozzle  201  (the origin of the second coordinate system) is greater than a threshold value, it is determined that said point cloud coordinates belong to the target coordinates that need to be repeated in step S 5 ; otherwise, if the processor  12  identifies the value of the distance from a point cloud point to the nozzle  201  (the origin of the second coordinate system) is less than a threshold value, it is determined that the point cloud coordinates belong to the target coordinates that require repeated execution of step S 4  and step S 5 . Herein, the threshold value may be a median, a mean, or a mode of the distance values, depending on the actual requirements. 
     Further, in the present embodiment, the processor  12  may also determine the number of times that the process of the spraying action to the plastering and rendering or merely the process of the plastering and rendering needs to be repeated based on the difference between each of the distance values and said threshold value. For example, once the difference is determined to be N times a predetermined value, it is determined that the target coordinate regarding said difference is an uneven part that needs to be repeated N times (steps S 4  and S 5 , or step S 5 ). If the difference is a positive value, the step that requires to be repeated is step S 5 ; otherwise, if the difference is a negative value, the step that requires to be repeated is step S 4  and S 5 . However, because the number of N shall be an integer, when the quotient of the difference and the predetermined value is not an integer, the value of N is equal to the result of rounding the quotient up/down. 
     It is a noteworthy fact that the abovementioned steps shall include the process of converting the coordinate of the target coordinates in the second coordinate system to the coordinates of the third coordinate system such that the target coordinates of step S 4  could be identified in step S 5 . 
     In addition, the processor  12  can also pre-position the nozzle  201  of the slurry supply apparatus  20  at a specific spraying start position, and then perform the spraying on the wall  3  according to a set movement path (S-shaped/or Z-shaped). Also, since the start position of the spraying action is the known coordinate in the second coordinate system, during actual execution, the processor  12  can control the movement of the robot  21  based on the positional relation between the nozzle  201  and the tool  214 . Accordingly, the set positional relation serves as a guide that directs the tool  214  to the position of the nozzle  201 , and thereafter acts as the starting position of the plastering and rendering. Said starting position of the spraying action may be any position on the wall  3 , which is not limited by the present invention. 
     As is understood by a person skilled in the art, the foregoing preferred than limiting of the present invention. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structure. While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.