Control method and system of crawler-type 3D printing robot capable of autonomously and movably printing

Abstract

The invention belongs to the related technical field of industrial robots, and discloses a control method and system of a crawler-type 3D printing robot capable of autonomously and movably printing. The method comprises the following steps that the current position and the target position of the 3D printing robot are obtained, the current motion path of the 3D printing robot moving from the current position to the target position is planned, and the 3D printing robot moves to the target position according to the planned motion path; acquiring a real-time relative pose between the head of the 3D printing robot and a preset marker, comparing the real-time relative pose with a preset relative pose, and if the real-time relative pose is inconsistent with the preset relative pose, planning a pose adjustment path of the head and adjusting the pose of the head according to the path until the real-time relative pose is consistent with the preset relative pose; and the 3D printing robot carries out printing at the current position and posture. By means of the 3D printing robot, the problem that the 3D printing robot cannot move autonomously and adjust the pose in a self-adaptive mode is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field related to industrial robots, and more specifically, relates to a control method and system for a crawler-type 3D printing robot capable of autonomous mobile printing. Background Art

[0002] The tracked 3D printing robot system capable of autonomous mobile printing is composed of a tracked vehicle system, a 3D printing module and a control system that can autonomously move and adaptively adjust its own posture. The tracked vehicle is used as a driving carrier, and the robotic arm is used as the actuator for 3D printing. Relevant control modules for mobile planning and adaptive adjustment of its own posture are added to ultimately complete the printing task of target structures that are beyond the coverage range of the robotic arm when the robot is stationary.

[0003] At present, in addition to the crawler-type 3D printing robot described in the present invention, there are two other 3D printing platforms with different structures (CN109878581B and CN 213675480U) in the current online patent library, which can also realize mobile printing. The other two mobile 3D printing platforms not only have redundant hardware structures and single functional structures, but also lack intelligent and adaptive control systems, and cannot enable the entire set of equipment to perform 3D printing tasks autonomously.

[0004] Among them, CN109878581B discloses a crawler walking device of a 3D printing robot and a 3D printing robot, wherein the overall device includes a small crawler printing actuator in the front and a large crawler material storage device in the rear, and the actuator and the material storage device are used to transfer materials through a bellows-type pipe. After analysis, it was found that the movement trajectory of the small crawler actuator structure was too fixed, and only straight lines and curve models with less curvature could be printed, so the digital models that the device could print were very limited. At the same time, this device physically separates the printing actuator and the material storage device, and cannot guarantee the absolute synchronization of the front and rear devices during mobile printing. The hardware structure design is cumbersome and not compact, which greatly increases the failure rate of material discharge during printing. In addition, the overall device does not have an intelligent decision-making control system, requires a high degree of human participation, and cannot be independently printed without human power. This is not in line with the current market trend of mobile 3D printing technology.

[0005] CN 213675480U discloses a crawler-type 3D printing mobile robot, the overall device of which includes a crawler vehicle and a vehicle-mounted 3D printing structure, wherein the support body of the vehicle-mounted 3D printing structure can adjust its height according to the requirements of the building to be printed. The invention of the overall device breaks the traditional 3D printing frame structure and changes the space limitation of 3D printing technology. Compared with CN109878581B, this device improves the storage method of materials, that is, the printing nozzle is directly fixedly connected to the storage box, but the port of the printing structure of this device can only print on a two-dimensional plane, and the printing in the third latitude direction is performed by simply adjusting the height of the support body. Therefore, only some three-dimensional models with small volume and simple construction structure can be printed, which is not flexible and cannot adapt to most construction scenes. In addition, the overall device does not have an intelligent decision-making control system like CN109878581B, requires high human participation, and cannot be independently printed without manpower. Accordingly, this field urgently needs to find a more complete solution, combine artificial intelligence technology, and innovate a mobile 3D printing technology that is more in line with the needs of the times. Summary of the invention

[0006] In view of the above defects or improvement needs of the prior art, the present invention provides a control method and system for a crawler-type 3D printing robot that can move and print autonomously, so as to solve the problem that the 3D printing robot cannot achieve autonomous movement and adaptively adjust its own posture.

[0007] To achieve the above object, according to one aspect of the present invention, a control method for a crawler-type 3D printing robot capable of autonomous mobile printing is provided, the method comprising the following steps:

[0008] Collect images around the 3D printing robot and determine whether there are obstacles within a preset range. If there are obstacles, control the 3D printing robot to move toward a side without obstacles until there are no obstacles within the preset range.

[0009] Obtaining the current position and target position of the 3D printing robot, planning a motion path for the current 3D printing robot to move from the current position to the target position, and the 3D printing robot moves to the target position according to the planned motion path;

[0010] Obtaining the real-time relative posture between the front of the 3D printing robot and the preset marker and comparing it with the preset relative posture; if the real-time relative posture is inconsistent with the preset relative posture, planning a posture adjustment path for the front of the robot and adjusting the posture of the front of the robot according to the path until the real-time relative posture is consistent with the preset relative posture;

[0011] The 3D printing robot prints at the current position and posture, thereby realizing autonomous movement and adaptive printing of the 3D printing robot.

[0012] Further preferably, the planned posture adjustment path of the vehicle head is obtained in the following manner:

[0013] An image of a preset marker is obtained at the current posture of the front of the 3D printing robot, features are extracted from the acquired image and matched with the features at the calibrated preset relative posture, and the posture adjustment path of the front of the vehicle is planned according to the angle difference between the current posture and the preset relative posture.

[0014] Further preferably, the feature extraction adopts a scale-invariant feature transformation method, a Harris corner detection method or a directional gradient histogram method, and the feature matching adopts a nearest neighbor matching method or a nearest neighbor ratio method.

[0015] According to another aspect of the present invention, there is provided a crawler-type 3D printing robot capable of autonomous mobile printing, the 3D printing robot comprising an image acquisition module, an image processing module, a motion path planning module, a posture adjustment path planning module, a motion control module, and a 3D printing module, wherein:

[0016] The image acquisition module is used to acquire images around the 3D printing robot;

[0017] The image processing module is connected to the image acquisition module, and is used to perform image processing on the image acquired by the image acquisition module, and judge whether there is an obstacle within a preset range of the 3D printing robot according to the result of the image processing, or judge the current position of the 3D printing robot according to the result of the image processing, or judge the real-time relative posture between the head of the 3D printing robot and a preset marker according to the result of the image processing, and judge whether the real-time relative posture is consistent with the preset relative posture;

[0018] The motion path planning module is connected to the image processing module, and is used to obtain the current position and target position of the 3D printing robot and plan the motion path of the 3D printing robot;

[0019] The posture adjustment path planning module is connected to the image processing module, and is used to obtain the real-time relative posture between the head of the 3D printing robot and the preset marker, and plan the posture adjustment path of the 3D printing robot;

[0020] The motion control module is connected to the motion path planning module and the posture adjustment planning module, and is used to control the motion of the 3D printing robot according to the planned motion path and posture adjustment path respectively;

[0021] The 3D printing module is used for performing 3D printing.

[0022] Further preferably, the 3D printing robot also includes a displacement sensing module, which is used to measure the distance between the 3D printing robot and its surrounding objects, so as to assist the graphics processing unit in obtaining the current position of the 3D printing robot and the real-time relative posture between the front of the 3D printing robot and the preset marker.

[0023] Further preferably, the displacement sensing module uses a plurality of ultrasonic sensors to measure the distance between the 3D printing robot and its surrounding objects.

[0024] Further preferably, the 3D printing module includes a 3D printing mechanism and a robotic arm, and the 3D printing mechanism is arranged at the end of the robotic arm for performing 3D printing according to a preset printing path.

[0025] Further preferably, the motion control module adopts a tracked vehicle chassis and a driving mechanism, and the driving mechanism drives the tracked chassis to move.

[0026] Further preferably, the motion control module, displacement sensing module and image acquisition module are controlled by PLC.

[0027] According to another aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, the computer program being used to implement the control method of the above-mentioned crawler-type 3D printing robot capable of autonomous mobile printing.

[0028] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0029] 1. The present invention determines the current position of the robot by intelligently identifying the images around the 3D printing robot, and plans the motion path according to the gap between the current position and the target position. In addition, the real-time relative posture of the front of the 3D printing robot is intelligently identified, and the posture adjustment path is planned according to the posture. Finally, the 3D printing robot moves according to the planned motion path and posture adjustment path, thereby realizing autonomous movement and adaptive posture adjustment of the 3D printing robot.

[0030] 2. The present invention combines modules such as image acquisition module, displacement perception module and motion path planning module to give the overall mobile 3D printing device a control system that can move autonomously and adaptively adjust its own posture, thereby achieving no human operation during the printing process. The equipment can autonomously move according to the planned path and adaptively adjust its own posture at each target point of the print. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flow chart of a control method of a crawler-type 3D printing robot capable of autonomous mobile printing constructed according to a preferred embodiment of the present invention;

[0032] Figure 2 It is a schematic diagram of the module structure of a crawler-type 3D printing robot capable of autonomous mobile printing constructed according to a preferred embodiment of the present invention;

[0033] Figure 3 It is a schematic diagram of the specific structure of a crawler-type 3D printing robot capable of autonomous mobile printing constructed according to a preferred embodiment of the present invention;

[0034] Figure 4 is a schematic diagram of the structure of the operation control module constructed according to the preferred embodiment of the present invention;

[0035] Figure 5 is a schematic structural diagram of a mechanical arm constructed according to a preferred embodiment of the present invention;

[0036] Figure 6 3D printing mechanism constructed according to the preferred embodiment of the present invention. In all the drawings, the same reference numerals are used to represent the same elements or structures, wherein:

[0037] 1-track, 2-image acquisition module, 3-displacement sensing module, 4-motion path planning module, 5-3D printing module, 6-3D printing mechanism, 7-chassis, 8-driving mechanism, 9-robot end effector, 10-joint, 11-robot chassis, 12-connecting rod, 13-motion control mechanism, 14-material storage box, 15-material delivery pipe, 16-servo motor, 17-pressurizer, 18-nozzle, 19-reducer, 20-feeding port, 21-spiral rod. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0039] like Figure 2 and 3 As shown, a crawler-type 3D printing robot capable of autonomous mobile printing comprises an image acquisition module 2, an image processing module, a motion path planning module 4, a posture adjustment path planning module, a motion control module, and a 3D printing module 5, wherein:

[0040] The image acquisition module 2 is used to acquire images around the 3D printing robot;

[0041] The image processing module is connected to the image acquisition module, and is used to perform image processing on the image acquired by the image acquisition module, and judge whether there is an obstacle within a preset range of the 3D printing robot according to the result of the image processing, or judge the current position of the 3D printing robot according to the result of the image processing, or judge the real-time relative posture between the head of the 3D printing robot and a preset marker according to the result of the image processing, and judge whether the real-time relative posture is consistent with the preset relative posture;

[0042] The motion path planning module 4 is connected to the image processing module and is used to obtain the current position and target position of the 3D printing robot and plan the motion path of the 3D printing robot;

[0043] The posture adjustment path planning module is connected to the image processing module, and is used to obtain the real-time relative posture between the front of the 3D printing robot and the preset marker, and plan the posture adjustment path of the 3D printing robot;

[0044] The motion control module is connected to the motion path planning module 4 and the posture adjustment planning module, and is used to control the motion of the 3D printing robot according to the planned motion path and posture adjustment path respectively;

[0045] The 3D printing module 5 is used for performing 3D printing.

[0046] In one embodiment of the present invention, the motion control module adopts a tracked vehicle, such as Figure 4 As shown, the crawler vehicle includes a chassis 7 and a driving mechanism 8. The lower end of the crawler vehicle is the chassis 7. The chassis includes crawlers 1 on both sides, a suspension system and a power system. The chassis 7 is connected to the frame by welding. The power system usually includes an electric motor and a transmission device. The output shaft of the electric motor is connected to the input shaft of the reducer through a coupling, and the output shaft of the reducer is connected to the driving wheel through a clutch. The suspension system is used to connect the vehicle body and the crawler, and plays a role in buffering and shock absorption. One end of the suspension system is connected to the frame, and the other end is connected to the supporting roller. The suspension system is connected to the frame and the supporting roller by bolts. The driving mechanism 8 includes a driving wheel, a guide wheel, a supporting roller and a tensioning device, wherein the crawler is wrapped around the driving wheel, the guide wheel and the supporting roller, and the appropriate tension is maintained by the tensioning device. The driving wheel is connected to the power system through a transmission device to drive the crawler to rotate. The driving wheel, the guide wheel and the supporting roller are connected to the chassis through bearings.

[0047] In one embodiment of the present invention, the 3D printing module 5 uses a 3D printing mechanical arm and a 3D printing mechanism connected to the end. The lower end of the mechanical arm is fixed to the crawler system by bolts, and the upper end is the mechanical arm body. The mechanical arm body is composed of multiple joints and connecting rods connected by bolts and bearings, and a motor and a reducer are arranged in the joint, and the connecting rod connects the joint. The motion control system inside the mechanical arm includes components such as a controller, a servo driver and a sensor. The controller is electrically connected to the servo driver, and the servo driver is connected to the joint motor by a cable. Sensors such as encoders and force sensors are installed on the joint. The end of the mechanical arm is connected to the 3D printing mechanism by a flange, and the 3D printing mechanism includes main parts such as a servo motor, a reducer, a pressurizer, a feed port, and a nozzle.

[0048] In one embodiment of the present invention, the image acquisition module 2 includes a camera, which is fixed to the top of a connecting plate between the 3D printing mechanism and the end effector, and is connected to the PLC controller through an electronic harness;

[0049] The image acquisition module and the displacement sensing module 3 both realize data interaction with the PC-side mobile printing platform through the PLC controller. In one embodiment of the present invention, the ultrasonic sensor / radar ranging sensor in the image acquisition module is installed on the front end of the chassis of the crawler vehicle and the baffles on both sides of the vehicle body, and is connected to the PLC controller through an electronic harness. At the same time, the 3D printing module is directly connected to the PC-side mobile printing platform through a digital interface. The PLC controller and the PC-side mobile printing platform are connected via EtherCAT.

[0050] In one embodiment of the present invention, for the 3D printing module, it preferentially uses the three-dimensional model design software Rhino to design a building structure suitable for 3D printing, and then uses the slicing software Simplify 3D to plan the printing path of the designed structure, and extracts the printing path of the Simplify 3D file through Python. Finally, the text file is converted into program instructions in the robot arm operation software Robot Studio, and the host computer PC realizes the motion control of the 3D printing robot arm through the wired communication connection with the robot arm body control box.

[0051] In one embodiment of the present invention, the 3D printing module preferentially uses a servo motor to provide rotational power for the spiral rod in the pressurizer, and configures a reducer to stabilize the rotation speed of the spiral rod so that the material used for printing in the pressurizer can be continuously extruded. The 3D printing mechanism preferentially uses a clamp structure to combine and fix the nozzle with the pressurizer to facilitate the replacement of the nozzle size and other functional modules. The 3D printing module physically fixes the storage box containing the pressure pump to the robot arm control box, and connects the storage box and the robot arm feed port with a rubber pipe with a smooth inner wall, realizing an integrated hardware structure design of "material storage-feeding-printing" to solve the problem that the traditional storage device cannot be moved and printed together with the printing equipment.

[0052] like Figure 2 As shown, the displacement sensing module 3 includes a wheel speed sensor, an odometer and an ultrasonic distance sensor. The wheel speed sensor is installed under the driving wheels on both sides of the tracked vehicle to obtain the rotation speed of the tracked wheel group. The odometer is installed in the middle of the vehicle body to calculate the relative displacement (X / Y axis movement distance) and heading angle change of the tracked vehicle. The ultrasonic distance sensor is installed on the outer side of the support plates on both sides outside the tracked vehicle's supporting wheels, as well as the front and rear sides of the front and rear of the vehicle, to measure the distance between the tracked vehicle and the target structure / obstacle, to determine the distance between the tracked vehicle body and the obstacle, and to assist the tracked vehicle in adjusting its own printing posture.

[0053] like Figure 5 As shown, the 3D printing module 5 includes a robot arm and a 3D printing mechanism 6, wherein the robot arm includes a robot arm chassis 11, a joint 10, a connecting rod 12, a motion control mechanism 13, and a robot arm end effector 9. The robot arm chassis 11 is mounted to the upper surface of the crawler chassis 7 by bolts. The core body of the 3D printing module 5 is the robot arm body, which is composed of a plurality of joints 10 and connecting rods 12. The motion control mechanism 13 receives the motion command of the mobile printing platform on the PC side to realize the movement of the robot arm. The robot arm end effector 9 is connected to the 3D printing mechanism execution system 6 by bolts.

[0054] like Figure 6 As shown, the 3D printing mechanism 6 includes a servo motor 16, a reducer 19, a spiral rod 21, a pressurizer 17, a feed port 20, and a nozzle 18. The servo motor 16 and the reducer 19 are connected by bolts to ensure that the spiral rod 21 can extrude materials at the required speed. The printing material can be connected to the feed port 20 through the storage box 14 and the feed pipe 15 and fed into the pressurizer 17. The pressurizer 17 and the nozzle 18 are fixed by a clamp, and different types of nozzles 18 can be replaced according to different printing requirements.

[0055] like Figure 1 As shown, a control method for a crawler-type 3D printing robot capable of autonomous mobile printing comprises the following steps:

[0056] Collect images around the 3D printing robot and determine whether there are obstacles within the preset range. If there are obstacles, control the 3D printing robot to move in a suitable direction without obstacles and adjust the front of the robot to a suitable posture until there are no obstacles within the preset range, so that the 3D printing robot has the working conditions for autonomous printing;

[0057] Obtaining the current position and target position of the 3D printing robot, planning a motion path for the current 3D printing robot to move from the current position to the target position, and the 3D printing robot moves to the target position according to the planned motion path;

[0058] Obtaining the real-time relative posture between the front of the 3D printing robot and the preset marker and comparing it with the preset relative posture; if the real-time relative posture is inconsistent with the preset relative posture, planning a posture adjustment path for the front of the robot and adjusting the posture of the front of the robot according to the path until the real-time relative posture is consistent with the preset relative posture;

[0059] The 3D printing robot prints at the current position and posture, thereby realizing autonomous movement and adaptive printing of the 3D printing robot.

[0060] In one embodiment of the present invention, the above-mentioned adaptive adjustment of its own posture includes five steps, namely, establishing a target identification database, feature extraction, feature matching, inverse problem solving, and posture adjustment, wherein: (1) establishing a target identification database: setting a target identification object, such as a square black and white QR code. Different feature point shapes are set at the four corners of the square QR code to facilitate the distinction of the four directions of the QR code: upper left, lower left, upper right, and lower right; (2) Feature extraction: Extract the color information, edge information, and corner point features of the square black and white QR code in the upper left, lower left, upper right, and lower right directions; (3) Feature matching: Match the extracted features with the known target identifiers in the database; (4) Inverse problem solving: After the visual system captures the photo of the square QR code of the target identifier, it returns the captured image information to the processing layer. The processing layer will perform data analysis on the received image corner direction information to determine the current posture state of the tracked vehicle; (5) Posture adjustment: After knowing the current posture of the tracked vehicle, the processing layer matches the pre-set posture state in the program, that is, sends the corresponding motion command to the controller, so that the guide wheel of the tracked vehicle completes the motion planning in the command, and finally corrects the posture deviation through feedback from the displacement sensing module to complete its own posture adjustment.

[0061] In one embodiment of the present invention, the process of autonomous movement includes three steps: in-camera parameter calibration, capture interface locking, and mathematical model establishment, among which: (1) in-camera parameter calibration: presenting a predetermined parameter coordinate system on the camera imaging screen and indicating the measurement unit; (2) capture interface locking: after the camera captures the target object, it locks its interface, that is, fixes the current camera focal length and the position of the target object in the coordinate system in the visual system, and the tracked vehicle stops moving immediately; (3) mathematical model establishment: mapping the coordinate position of the target object in the visual system with its actual distance from the tracked vehicle.

[0062] For the control system that can autonomously move and adaptively adjust its own posture, a visual perception module and a displacement perception module are added to the tracked vehicle. Among them, the visual perception module contains an automatically rotating pan-tilt camera, and the displacement perception module contains 4 ultrasonic sensors. It should be noted that the ultrasonic sensor of the automatically rotating pan-tilt camera is used to monitor the obstacle information around the robot to avoid collision.

[0063] The function of autonomously moving and adaptively adjusting its own posture is realized by combining the visual perception system with the identification QR code (a circular center point is set on the surface of the QR code image, and the center point is marked with the position of the current QR code in the entire set path). It integrates multiple algorithms such as QR code detection, image processing, perspective transformation, and geometric calculation to design an algorithm structure and control logic for purely visual autonomous movement and adjustment of the vehicle body posture.

[0064] The following is the complete workflow of the crawler-type 3D printing robot of the present invention for autonomous movement and adaptive adjustment of the body posture:

[0065] Step 1: Initialization

[0066] (1) Start the robot and initialize the visual perception module and ultrasonic sensor module to ensure that the data is accurate and reliable; load the preset QR code information database so that the corresponding position information and instructions can be parsed for different QR codes when they are recognized; and configure four ultrasonic sensors on the front, back, left, and right sides of the tracked vehicle to monitor the obstacle avoidance distance value for the alarm.

[0067] Step 2: Obstacle Detection and Avoidance

[0068] (1) Ultrasonic sensors detect surrounding obstacles in real time and calculate the distance. If the distance is less than or equal to the set alarm value, a warning signal is immediately sent to the central controller. If there is no warning information, it means that the area around the vehicle is safe and the vehicle can adjust its posture.

[0069] (2) After receiving the alarm signal, the host computer issues corresponding motion instructions to the crawler vehicle drive module based on the alarm direction information.

[0070] Step 3: Adaptive adjustment of vehicle body posture

[0071] (1) Arrange the QR codes on the planned path according to a certain azimuth angle. Assume that the expected angle of the QR code relative to a fixed reference object (such as the north direction) is target_dir;

[0072] (2) Fix the pan / tilt camera with automatic rotation function to the body of the crawler vehicle and reset the pan / tilt to its initial position, which is consistent with the direction of the vehicle head;

[0073] (3) The PTZ camera searches for the current order identification QR code image within the spatial range;

[0074] (4) After capturing the current sequence identification QR code image, calibrate the camera coordinate origin and the QR code center point to coincide with each other, and record the current gimbal azimuth current_theta;

[0075] (5) Calculate the angle difference adjustment_agle of the tracked vehicle relative to the preset direction of the QR code, that is, adjustment_angle = target_dir - current_theta % 360;

[0076] (6) The change value of the pan-tilt azimuth angle adjustment_angle is fed back to the central controller, and the central controller issues corresponding posture adjustment motion instructions (left / right track movement speed and time) to the tracked vehicle drive module.

[0077] Step 4: Autonomous Movement

[0078] (1) After completing the adaptive adjustment of the vehicle body posture, the camera coordinate origin is recalibrated to coincide with the center point of the current order identification QR code;

[0079] (2) Two solutions (can be selected according to actual conditions):

[0080] First, the size of the QR code center point displayed in the camera is used (calculated through perspective transformation and known camera parameters), and the focal length of the lens is constant. Through the control model training, the values ​​of the coordinate quadrant (x, y) in the lens and the actual distance between the current vehicle head and the QR code of the marker are used to form a mapping relationship data model, that is, [(x, y, z)|(x, y)] array data. When the 3D printing robot is actually working, the collected visual and displacement information can be matched in the established database model to obtain the specific distance D that the current tracked vehicle needs to move autonomously;

[0081] The second is to directly equip the camera on the rotating gimbal as a depth camera. After calibrating and aligning the origin of the lens coordinates and the center point of the QR code, the depth camera system can directly obtain the distance a between the lens and the QR code in the real scene, and record the pitch angle φ of the gimbal at this time. The horizontal distance d between the front of the vehicle and the current printed point identification code is obtained through a·cosφ. The distance D that the front of the vehicle needs to move forward and backward is D=d-ddir, where ddir is the preset horizontal distance between the front of the vehicle and the identification QR code. In particular, the identification QR code is installed on the support rod, and the height of the support rod can be set according to the situation.

[0082] After collecting relevant information of the visual perception system, the central controller obtains the data D value through the preset algorithm structure (logical scheme above), according to the pre-set fuzzy control rule library, namely:

[0083] Taking D value as the standard, if D<0, it means the vehicle body needs to move backward, and the feedback signal is "0"; if D>0, it means the vehicle body needs to move forward, and the feedback signal is "1". The specific distance of moving backward or forward is determined by the |D| value according to the formula: Number of motor pulses of crawler vehicle = |D|* conversion coefficient K; where the conversion coefficient K is calculated from the mechanical structure of the crawler vehicle and the performance parameters of the motor.

[0084] (3) After receiving the feedback information from the central controller, the host computer issues corresponding motion instructions to the crawler vehicle drive module (setting the moving speed and moving time of the left and right crawlers) according to the pre-set instruction library.

[0085] Step 5: Loop execution

[0086] (1) According to the set 3D printing task, repeat the above steps to realize the robot's autonomous movement and adaptive adjustment of the vehicle body posture until the entire printing task is completed.

[0087] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A control method for a crawler-type 3D printing robot capable of autonomous mobile printing, characterized in that: The method comprises the following steps: Collect images around the 3D printing robot and determine whether there are obstacles within a preset range. If there are obstacles, control the 3D printing robot to move toward a side without obstacles until there are no obstacles within the preset range. Obtaining the current position and target position of the 3D printing robot, planning a motion path for the current 3D printing robot to move from the current position to the target position, and the 3D printing robot moves to the target position according to the planned motion path; Obtaining the real-time relative posture between the front of the 3D printing robot and the preset marker and comparing it with the preset relative posture; if the real-time relative posture is inconsistent with the preset relative posture, planning a posture adjustment path for the front of the robot and adjusting the posture of the front of the robot according to the path until the real-time relative posture is consistent with the preset relative posture; The 3D printing robot prints at the current position and posture, thereby realizing autonomous movement and adaptive printing of the 3D printing robot.

2. The control method of a crawler-type 3D printing robot capable of autonomous mobile printing as claimed in claim 1, characterized in that: The planned vehicle head posture adjustment path is obtained in the following manner: An image of a preset marker is obtained at the current posture of the front of the 3D printing robot, features are extracted from the acquired image and matched with the features at the calibrated preset relative posture, and the posture adjustment path of the front of the vehicle is planned according to the angle difference between the current posture and the preset relative posture.

3. The control method of a crawler-type 3D printing robot capable of autonomous mobile printing as claimed in claim 2, characterized in that: The feature extraction adopts a scale-invariant feature transformation method, a Harris corner point detection method or a directional gradient histogram method, and the feature matching adopts a nearest neighbor matching method or a nearest neighbor ratio method.

4. A 3D printing robot that performs printing according to the control method according to any one of claims 1 to 3, characterized in that: The 3D printing robot includes an image acquisition module, an image processing module, a motion path planning module, a posture adjustment path planning module, a motion control module, and a 3D printing module, wherein: The image acquisition module is used to acquire images around the 3D printing robot; The image processing module is connected to the image acquisition module, and is used to perform image processing on the image acquired by the image acquisition module, and judge whether there is an obstacle within a preset range of the 3D printing robot according to the result of the image processing, or judge the current position of the 3D printing robot according to the result of the image processing, or judge the real-time relative posture between the head of the 3D printing robot and a preset marker according to the result of the image processing, and judge whether the real-time relative posture is consistent with the preset relative posture; The motion path planning module is connected to the image processing module, and is used to obtain the current position and target position of the 3D printing robot and plan the motion path of the 3D printing robot; The posture adjustment path planning module is connected to the image processing module, and is used to obtain the real-time relative posture between the head of the 3D printing robot and the preset marker, and plan the posture adjustment path of the 3D printing robot; The motion control module is connected to the motion path planning module and the posture adjustment planning module, and is used to control the motion of the 3D printing robot according to the planned motion path and posture adjustment path respectively; The 3D printing module is used for performing 3D printing.

5. The 3D printing robot according to claim 4, characterized in that: The 3D printing robot also includes a displacement sensing module, which is used to measure the distance between the 3D printing robot and its surrounding objects, so as to assist the graphics processing unit in obtaining the current position of the 3D printing robot and the real-time relative position between the front of the 3D printing robot and the preset marker.

6. The 3D printing robot according to claim 5, characterized in that: The displacement sensing module uses multiple ultrasonic sensors to measure the distance between the 3D printing robot and its surrounding objects.

7. The 3D printing robot according to claim 4 or 6, characterized in that: The 3D printing module includes a 3D printing mechanism and a robotic arm. The 3D printing mechanism is arranged at the end of the robotic arm and is used to perform 3D printing according to a preset printing path.

8. The printing robot according to claim 4 or 6, characterized in that: The motion control module adopts a crawler vehicle chassis and a driving mechanism, and the driving mechanism drives the crawler chassis to move.

9. The 3D printing robot according to claim 8, characterized in that: The motion control module, displacement sensing module and image acquisition module are controlled by PLC.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The computer program is used to implement the control method of a crawler-type 3D printing robot capable of autonomous mobile printing as described in any one of claims 1-3.

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