Drive-by-wire autonomous moving multifunctional welding robot

Abstract

The invention relates to a drive-by-wire autonomous movement multifunctional welding robot, which belongs to the technical field of wireless communication welding, and comprises a drive-by-wire autonomous movement chassis, an autonomous movement sensing system and a high-precision depth camera, the autonomous movement sensing system and the drive-by-wire brake system are respectively assembled on the drive-by-wire autonomous movement chassis; the high-precision depth camera and a welding gun of the welding device are fixed on the cooperative mechanical arm; the device has the beneficial effects that environment point cloud is recognized through the navigation laser radar, the device runs along a planned path, the drive-by-wire autonomous moving chassis can move to a designated position for welding according to actual needs, multiple welding robots do not need to be arranged, the cost is further reduced, after the device is braked in a drive-by-wire mode, a hub does not have mechanical gaps after the device reaches a station, and the welding efficiency is improved. And in addition, the cooperative mechanical arm is used, so that the welding gun can freely move within a certain range, and welding is more flexible.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wireless communication welding, and particularly relates to a drive-by-wire autonomous mobile multifunctional welding robot. BACKGROUND

[0002] In the field of industrial welding, the welding operation of large workpieces or complex working conditions requires increasingly improved flexibility, operation range and automation degree of equipment. Traditional welding equipment mostly relies on fixed installation mode or needs external power supply to provide power, and is obviously limited in operation area. When facing large workpiece welding, multiple equipment needs to be arranged for cooperation, resulting in increased production cost.

[0003] The existing mobile welding robot has defects in adaptability to complex road conditions. When the chassis passes through a bumpy road, the wheels are prone to uneven contact with the ground, affecting the operation stability. At the same time, the traditional brake system has mechanical clearance, and the equipment is prone to shaking after reaching the working position, which makes it difficult to ensure the welding precision.

[0004] In terms of weld seam recognition and welding flexibility, some equipment relies on manual teaching and cannot adapt to different types of weld seams. In addition, the operation angle of the mechanical arm is limited, which is prone to collision with other components. Moreover, the spatter easily damages the tire, and the sensor synchronization is poor, which also restricts the welding efficiency and service life of the equipment. SUMMARY

[0005] The application provides a drive-by-wire autonomous mobile multifunctional welding robot, which is used to solve the technical problem that the welding robot in the prior art cannot be effectively controlled to move autonomously, and can drive along a planned path by recognizing environment point clouds through a navigation laser radar.

[0006] In order to achieve the above purpose, the application realizes the following technical scheme: a drive-by-wire autonomous mobile multifunctional welding robot, comprising:

[0007] A drive-by-wire autonomous mobile chassis, a welding device, a collaborative mechanical arm and an external load mobile battery are installed on the drive-by-wire autonomous mobile chassis;

[0008] An autonomous mobile perception system and a drive-by-wire brake system are respectively arranged on the drive-by-wire autonomous mobile chassis;

[0009] A high-precision depth camera, a welding gun of the welding device and the collaborative mechanical arm are fixed on the collaborative mechanical arm.

[0010] Optionally, the self-moving chassis adopts any one of Ackerman structure, differential drive structure or four-wheel drive structure, the ground clearance of the chassis is not less than 10 cm, an obstacle removing brush is arranged at the wheel surface, a T-shaped guide rail is arranged on the upper surface of the chassis, the frame body is connected with the front steering wheel system and the rear driving wheel system through a hinged seat, and a shock absorber and a shock absorbing spring with a stiffness coefficient of 20 N / mm are arranged between the three.

[0011] Optionally, the self-moving sensing system comprises an obstacle avoidance laser radar and a navigation laser radar; the obstacle avoidance laser radar is installed at the front of the self-moving chassis, adopts a non-repeated scanning mode, supports Linux / Windows / ROS development environment and an Autoware open source platform;

[0012] The navigation laser radar adopts a 32-line beam 70° vertical field of view angle and a 55° downward exploration angle, is installed at the middle axis of the forward direction of the self-moving chassis, is 10 cm away from the plane of the chassis, and adopts a repeated scanning mode.

[0013] Optionally, the obstacle avoidance laser radar and the navigation laser radar realize time synchronization through hardware triggering, the navigation laser radar constructs a PCD format map based on a LIO-SAM fusion node, generates a light-weight navigation map after filtering and down-sampling processing, and the obstacle avoidance laser radar detects obstacles in real time and triggers braking and avoidance.

[0014] Optionally, the external load mobile battery is a replaceable structure, is fixed to the self-moving chassis, supplies power to the controller and the entire robot, and realizes autonomous mobile welding operation without external power supply.

[0015] Optionally, the self-moving chassis adopts any one of Ackerman structure, differential drive structure or four-wheel drive structure, the ground clearance of the chassis is not less than 10 cm, an obstacle removing brush is arranged at the wheel surface, a T-shaped guide rail is arranged on the upper surface of the chassis, the frame body is connected with the front steering wheel system and the rear driving wheel system through a hinged seat, and a shock absorber and a shock absorbing spring with a stiffness coefficient of 20 N / mm are arranged between the three.

[0016] Optionally, the brake trigger conditions of the self-moving chassis include that the closest distance of the front obstacle is less than a dynamic safety threshold, the time to collision TTC is less than 1 s, or a manual emergency stop instruction is received; the brake strength is dynamically adjusted according to the trigger condition, the response time is not more than 10 ms, and the anti-lock control function is possessed.

[0017] Optionally, the collaborative mechanical arm is a six-axis structure, is installed above the rear driving motor of the self-moving chassis, the rear driving motor is located at the middle axis position of the chassis, the working angle of the first axis of the collaborative mechanical arm is based on the middle axis line of the chassis ± 85°, and collision with the welding device is avoided.

[0018] Optionally, the welding device comprises a welding machine and a wire feeder, both of which are fixed at the middle position of the front and rear axle plates of the drive-by-wire autonomous mobile chassis, and the welding gun is fixed to the sixth axis of the collaborative robot arm through a support and works with the high-precision depth camera.

[0019] Optionally, the high-precision depth camera is a structured light binocular camera, which realizes micron-level precision weld seam identification by tool coordinate system and camera coordinate system calibration combined with a weld seam extraction algorithm, supports point cloud matching and algorithm adaptive switching of multiple weld seam types such as butt joints, corner joints and lap joints.

[0020] The beneficial effects of the present application are:

[0021] The drive-by-wire autonomous mobile chassis, i.e., the drive-by-wire mobile multifunctional welding robot, can drive along the planned path by recognizing the environment point cloud through the navigation laser radar, has the function of autonomous navigation, and is provided with an external load mobile battery, so that the welding device realizes no external power supply, even if the welding workpiece is large, the drive-by-wire autonomous mobile chassis can be moved to the specified position for welding according to the actual needs, without the need to arrange multiple welding robots, further reducing the cost, and the device drive-by-wire brake makes the rear hub of the welding device reach the work position without mechanical gap, thereby improving the welding quality, and the use of the collaborative robot arm enables the welding gun to move freely within a certain range, making the welding more flexible. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] Figure 1 is the structure diagram of the autonomous mobile chassis of the present application;

[0024] Figure 2 is the structure diagram of the drive-by-wire autonomous mobile multifunctional welding robot of the present application.

[0025] Figure: 1-drive-by-wire autonomous mobile chassis, 2-autonomous mobile sensing system, 2-1-obstacle avoidance laser radar, 2-2-navigation laser radar, 3-welding device, 3-1-electric welding machine, 3-2-welding gun, 4-collaborative robot arm, 5-high-precision depth camera, 6-drive-by-wire brake system, 7-external load mobile battery, 8-front steering wheel system, 9-rear drive wheel system. DETAILED DESCRIPTION

[0026] The embodiments of the present application will be described in detail below with reference to the drawings.

[0027] In the description of the present application, it needs to be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0028] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0029] In the description of the present application, it needs to be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be welding, or bolted connection, or riveting; it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0030] Embodiment 1

[0031] Reference Figure 2 The embodiment provides a drive-by-wire autonomous mobile multifunctional welding robot, specifically a drive-by-wire autonomous mobile multifunctional welding robot, comprising: a drive-by-wire autonomous mobile chassis 1, an autonomous mobile sensing system 2 having an obstacle avoidance laser radar 2-1 and a navigation laser radar 2-2, a welding device 3, a collaborative manipulator 4, a high-precision depth camera 5, a drive-by-wire brake system 6 and an external load mobile battery 7.

[0032] The height of the support feet at the bottom of the mobile chassis frame needs to be consistent, the shock absorbing spring seat is fixed at the suspension mounting point reserved in the frame, the shock absorbing spring is sleeved into the spring seat, the top is connected with the wheel support, the steering gear support is connected with the front end of the frame, and the support and the frame are perpendicular.

[0033] The bearing is pressed into the steering cup bearing hole, the shaft end is fixed with the wheel support, the connecting rod is used to connect the swing arms of the left and right steering cups, and the ball heads at both ends of the connecting rod need to be completely embedded in the swing arm holes. Push the steering cup to ensure that the left and right rotate synchronously.

[0034] Install the rocker arm on the steering engine output shaft, connect the rocker arm with the left (or right) steering cup swing arm with a pull rod, and adjust the length of the pull rod to the middle of the steering engine. When the steering wheel is in the straight ahead direction.

[0035] As shown in Figure 1 The motor support is fixed and installed on the driving system at the rear end of the vehicle frame, and the support needs to be parallel to the vehicle frame. The driving motor is installed on the support, and the motor output shaft is directed towards the wheel direction, and the shaft is aligned with the wheel coupling. The coupling is sleeved into the motor shaft at one end, and the other end is sleeved into the wheel shaft, and the synchronous rotation of the motor is checked. One end of the wire-controlled autonomous mobile chassis 1 is provided with a first hinged seat, and the front steering wheel system 8 is connected with the vehicle frame body through the first hinged seat; the other end of the vehicle frame body is provided with a second hinged seat, and the rear driving wheel system 9 is connected with the vehicle frame body through the second hinged seat; the shock absorber is connected with the vehicle frame body, the front steering wheel system and the rear driving wheel system. The front steering wheel system 8 swings up and down around the first hinged seat under the action of the shock absorber, and the rear driving wheel system 9 swings up and down around the second hinged seat under the action of the shock absorber. The suspension and the vehicle frame are provided with a damping spring (stiffness coefficient 20N / mm); the upper surface of the wire-controlled autonomous mobile chassis 1 is provided with a T-shaped guide rail, and the front and rear four shock absorbers have a ground clearance of more than 10cm, and a brush is added at the wheel surface to solve the problem of tire damage caused by splashing; the welding device 3 includes a welding machine and a wire feeder fixed in the middle position of the front and rear shaft plates of the wire-controlled autonomous mobile chassis 1, which increases the stability during driving. The wire-controlled autonomous mobile chassis 1 is additionally provided with an external load mobile battery 7, which solves the problem of external power supply of the traditional welding robot, improves the freedom degree of welding travel, and realizes the integration of autonomous mobile welding.

[0036] The navigation laser radar 2-2 adopts a speed-teng 32-line bundle 70° vertical field of view, and a special fixed support is connected to the rear of the wire-controlled autonomous mobile chassis 1, which is installed on the middle axis of the wire-controlled autonomous mobile chassis 1 in the forward direction based on the plane height of 10cm of the wire-controlled mobile chassis 1. Through offline map construction: start LIO-SAM fusion node and RViz, control the Ackerman chassis to slowly drive in the target scene (such as warehouse, park), collect environment point cloud operation;

[0037] rosrunpcl_rospointcloud_to_pcdinput:= / lio_sam / mapping / cloud_Registered will save the fusion point cloud as a PCD format map; use CloudCompare tool to filter the map (remove outliers), downsample (voxel size 0.1m), and generate a lightweight navigation map.

[0038] Positioning initialization configuration:

[0039] In the navigation start file navigation.launch, set the initial pose topic / initialpose (message type geometry_msgs / PoseWithCovarianceStamped) to start after RViz "2DPoseEstimate" tool, mark the actual position of the chassis on the map, complete the positioning initialization.

[0040] The obstacle avoidance laser radar 2-1 has the characteristics of supporting multiple development environments such as Linux / Windows / ROS and various development languages such as C / C++ / Python, and is fully compatible with the Autoware open source platform. At the same time, it provides algorithm examples such as SLAM mapping, navigation and obstacle avoidance, and is equipped with software that can display, record, play back, analyze three-dimensional point clouds in real time, and support advanced functions such as product setting, external parameter adjustment, and safety area setting. The line control autonomous mobile chassis 1 is installed in front of the line control autonomous mobile chassis 1, and the line control autonomous mobile chassis 1 brakes and avoids obstacles during movement to avoid damage to robot components or obstacles.

[0041] The line control brake system 6 is installed on the line control autonomous mobile chassis 1. Since the structure of the line control autonomous mobile chassis 1 is based on motor braking, the line control braking module is fixed: the line control braking module is installed at the front end of the chassis brake pipeline through a customized bracket, ensuring that the module is parallel to the chassis reference surface. Connect the brake pipeline: the input end of the brake module is connected to the brake master pump, and the output end is connected to the transmission wheel brake pump in two ways. The pipeline interface is wrapped with raw material belt to prevent brake oil leakage.

[0042] Power line: the line control braking module is connected to the 12V / 24V vehicle power supply (requires independent insurance, rated current 20A).

[0043] Signal line: the module CAN_H / CAN_L pins are connected to the chassis vcu CAN interface through twisted pair lines, and the wheel speed sensor signal is connected to the module signal input end;

[0044] Safety circuit: one end of the double-relay is connected to the module enable pin, and the other end is connected to the navigation system safety signal and emergency stop button respectively, forming a double safety guarantee.

[0045] Signal interaction architecture design (based on CAN+ROS double link).

[0046] Main link (CAN bus): responsible for real-time transmission of brake command and state feedback, the navigation system sends "target brake strength" (0-100%, corresponding to 0-200N brake force) through the CAN bus, and the line control braking module feeds back "actual brake force" and "system status" (normal / fault), with a transmission period of 10ms; Adjust the mapping relationship through real vehicle testing to ensure that the brake strength matches the obstacle distance and speed.

[0047] Line control brake module power on, send 0% brake strength instruction, record the reference voltage output by the module, if the deviation > 0.1V, adjust the zero point through the module calibration software; send 100% brake strength instruction, measure the actual brake force, if the deviation from 200N is > 5%, adjust the module gain parameter until the error is ≤3%.

[0048] Brake trigger and decision (based on laser radar data), trigger condition judgment:

[0049] Distance trigger: the closest distance of the front obstacle < safety threshold (adjust dynamically according to speed, such as threshold 1.5m when speed 0.5m / s, threshold 3m when speed 1m / s);

[0050] Collision risk trigger: based on the obstacle motion speed and the current speed of the chassis, calculate the collision time TTC < 1s;

[0051] Manual trigger: press the emergency stop button or send "emergency brake" instruction through RViz.

[0052] Brake level decision: the navigation system calls the "brake strength mapping table" according to the trigger condition to determine the target brake strength (such as 100% strength when TTC=0.5s), and generates brake instruction.

[0053] Instruction transmission and execution (millisecond level response);

[0054] The navigation system sends brake instructions through CAN bus (ID: 0x100, data segment contains brake strength [0-255n]), and at the same time sends backup instructions through ROS topic / brake_cmd to ensure double link redundancy; after receiving the instruction, the line control brake module completes the verification (checks the data integrity, validity of the timestamp) within 10ms, if the CAN instruction is abnormal, automatically switch to the ROS backup instruction. During execution, the module real-time collects wheel speed sensor data, if the wheel speed is detected to drop sharply (with the risk of locking), automatically reduce the brake force (such as from 80% to 50%), realize anti-lock control; the module feeds back "actual brake force", "wheel speed", "system status" (every 10ms) through CAN bus, the navigation system receives and updates the brake state after receiving, which is used for path planning adjustment.

[0055] The brake release and recovery (cohesion navigation continues to drive) through the electromagnetic brake after the existence of mechanical clearance, the robot shakes left and right when welding, affecting the welding precision, characterized in that the line control brake is installed to control the brake lock of the chassis hub when it reaches the working position, and the welding precision is improved. The line control autonomous mobile chassis 1 is provided with a collaborative mechanical arm 4 and a welding device 3, the mechanical arm 4 and the high-precision depth camera 5 are fixed on the line control autonomous mobile chassis 1, the welding device 3 includes an electric welder 3-1 and a welding gun 3-2, the electric welder 3-1 is fixed on the line control autonomous mobile chassis 1 between the front and rear shaft plates, the downward gravity of the electric welder 3-1 plays a stabilizing role in the navigation driving process of the chassis, the collaborative mechanical arm 4 is connected to the collaborative mechanical arm base and is installed above the rear drive motor of the mobile chassis, and the rear wheel drive motor is located at the gravity center position of the mobile chassis.

[0056] The welding device 3 is installed on the line control mobile chassis 1 between the front and rear shaft plates, and the welding gun 3-2 of the welding device 3 and the high-precision depth camera 5 are fixed on the sixth shaft of the mechanical arm 4 through the connecting piece, wherein the line control autonomous mobile chassis car 1 is a line control autonomous mobile multifunctional welding robot, which can generate an environment map by recognizing the environment through the navigation laser radar and drive along the specified guide path, has the function of autonomous navigation, and can avoid obstacles by braking through the obstacle avoidance laser radar in the unfamiliar environment. Even if the welding workpiece is large, the line control autonomous mobile chassis 1 can move to the specified position for welding according to the actual needs, and is more flexible. Without arranging multiple welding robots, the cost is further reduced, and the use of the collaborative mechanical arm 4 enables the welding gun 3-2 to move freely at a certain angle, making the welding more flexible.

[0057] As a further preferred scheme: the mechanical arm 4 is a six-axis collaborative mechanical arm, which has higher flexibility and can complete more complex actions. Further, the rear wheel system of the line control autonomous mobile chassis car 1 is provided with a line control brake system 6, when the line control autonomous mobile chassis 1 reaches the specified working position and stops through the navigation laser radar 2-2, the welding gun 3-2 is set as the origin of the coordinate system and the high-precision depth camera 5 is used to identify the weld for welding, the line control brake system 6 can be started to make the hub lock, preventing the line control autonomous mobile chassis 1 from shaking due to the mechanical clearance generated by the electromagnetic brake during welding, affecting the welding quality. When the line control autonomous mobile chassis 1 needs to move to the next working point after completing the welding, the line control brake system 6 is turned off, and the autonomous mobile sensing system 2 can leave the working area.

[0058] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A by-wire autonomous mobile multi-functional welding robot, characterized by, Comprise: A drive-by-wire autonomous mobile chassis (1) on which a welding device (3), a collaborative robot arm (4) and an external load mobile battery (7) are installed; An autonomous mobile perception system (2) and a drive-by-wire brake system (6) are respectively installed on the drive-by-wire autonomous mobile chassis (1); A high-precision depth camera (5) is fixed to the welding torch (3-2) of the welding device (3) on the collaborative robot arm (4).

2. A wire controlled autonomous mobile multi-functional welding robot according to claim 1, characterized in that, The drive-by-wire autonomous mobile chassis (1) adopts any one of Ackerman structure, differential drive structure or four-wheel four-drive structure, the chassis has a front and rear ground clearance of not less than 10 cm, an obstacle clearing brush is arranged at the wheel surface, a T-shaped guide rail is arranged on the upper surface of the chassis, the frame body is connected with the front steering wheel system (8) and the rear drive wheel system (9) through a hinged seat, and a shock absorber and a shock absorbing spring with a stiffness coefficient of 20 N / mm are arranged between the three.

3. A wire controlled autonomous mobile multi-functional welding robot according to claim 1, characterized in that, The autonomous mobile perception system (2) comprises an obstacle avoidance laser radar (2-1) and a navigation laser radar (2-2); the obstacle avoidance laser radar (2-1) is installed in front of the drive-by-wire autonomous mobile chassis (1), adopts a non-repetitive scanning mode, supports Linux / Windows / ROS development environment and Autoware open source platform; The navigation laser radar (2-2) adopts a 32-line beam with a 70° vertical field of view and a 55° downward angle, is installed on the central axis of the drive-by-wire autonomous mobile chassis (1) in the forward direction, is 10 cm away from the chassis plane, and adopts a repetitive scanning mode.

4. The autonomous mobile multi-functional welding robot by wire of claim 1, wherein, The obstacle avoidance laser radar (2-1) and the navigation laser radar (2-2) realize time synchronization through hardware triggering, the navigation laser radar (2-2) constructs a PCD format map based on a LIO-SAM fusion node, generates a lightweight navigation map after filtering and down-sampling processing, and the obstacle avoidance laser radar (2-1) detects obstacles in real time and triggers brake avoidance.

5. A wire controlled autonomous mobile multi-functional welding robot according to claim 1, wherein, The external load mobile battery (7) is a replaceable structure, is fixed to the drive-by-wire autonomous mobile chassis (1), supplies power for the controller and the whole robot, and realizes autonomous mobile welding operation without external power supply.

6. A wire controlled autonomous mobile multi-functional welding robot according to claim 1, characterized in that, The drive-by-wire brake system (6) is installed at the front end of the chassis brake pipeline through a customized support, is connected with a 12V / 24V vehicle independent backup power supply, interacts with the navigation system signal through CAN+ROS double link, has a motor brake and a mechanical brake dual brake structure, can realize brake hub locking, and eliminates mechanical clearance.

7. A wire controlled autonomous mobile multi-functional welding robot according to claim 6, characterized in that, The brake trigger conditions of the drive-by-wire brake system (6) include that the closest distance of the front obstacle is less than the dynamic safety threshold, the time to collision TTC is less than 1s, or a manual emergency stop instruction is received; the brake strength is dynamically adjusted according to the trigger condition, the response time is not more than 10 ms, and the anti-lock control function is possessed.

8. A wire controlled autonomous mobile multi-functional welding robot according to claim 1, wherein, The collaborative robot arm (4) is a six-axis structure, is installed above the rear drive motor of the drive-by-wire autonomous mobile chassis (1), the rear drive motor is located at the central axis position of the chassis, and the working angle of the first axis of the collaborative robot arm (4) is based on the central axis of the chassis ±85°, so as to avoid collision with the welding device.

9. A wire controlled autonomous mobile multi-functional welding robot according to claim 1, wherein, The welding device (3) includes a welding machine and a wire feeder, which are fixed together at the middle position of the front and rear shaft plate surfaces of the line-controlled autonomous mobile chassis (1), and a welding gun (3-2) is fixed to the sixth axis of the collaborative mechanical arm (4) through a support and works cooperatively with the high-precision depth camera (5).

10. A wire controlled autonomous mobile multi-functional welding robot according to claim 9, characterized in that, The high-precision depth camera (5) is a structured light binocular camera, which is calibrated through a tool coordinate system and a camera coordinate system, combined with a weld extraction algorithm, to realize micron-level precision weld identification and support point cloud matching and algorithm adaptive switching of multiple weld types such as butt joints, corner joints and lap joints.

Images