Multi-legged wheeled intelligent welding robot

Abstract

This utility model discloses a multi-legged wheeled intelligent welding robot, relating to the field of welding technology, aiming to solve the pain points of welding operations in high-risk, complex terrain, and confined spaces. It includes a torso, eight limbs, and a welding arm; the torso has an extension axis at the upper part, a lidar at the front, an integrated control system and IMU system, and a hip joint module at the lower part; the limbs include thigh and knee joint modules, lower legs, and electrically driven wheels, which can coordinate flexion and extension to adjust body balance; the welding arm includes a flexible arm, a welding torch, and a teach-free camera, mounted on the extension axis. During operation, the lidar models and plans the path, the limbs drive the torso to move across all terrains, the teach-free camera identifies weld seams, and the flexible arm drives the welding torch for precise welding and real-time parameter adjustment. This robot can replace manual high-risk operations, adapt to multiple scenarios, and improve welding quality and efficiency.

Description

Technical Field

[0001] This utility model relates to the field of welding technology, specifically to a multi-legged wheeled intelligent welding robot. Background Technology

[0002] In fields such as oil and gas chemicals, shipbuilding, steel structure construction, rail transportation, energy and power, and nuclear power engineering, welding operations are often required in complex scenarios such as high-risk, large outdoor structures, complex terrain, and confined spaces. Existing welding methods often have certain defects and shortcomings, for example:

[0003] I. Welding operations in high-risk environments (such as nuclear power plants, high-temperature and high-radiation environments)

[0004] Existing solutions mainly rely on "manual labor + simple protection" or "customized fixed equipment".

[0005] Manual welding: Welders wear heavy protective clothing (such as lead aprons and heat-resistant suits) to enter high-risk areas and work with a welding torch. For example, in the welding of fuel grids in nuclear power plants, welders need to crawl into narrow spaces. The protective clothing can weigh 20-30 kilograms, and a single operation usually does not exceed 30 minutes (due to radiation dose and physical limitations). Moreover, the quality of the weld depends on the welder's experience, and the pass rate fluctuates greatly (approximately 70%-85%).

[0006] Customized fixed equipment: Track-mounted or wall-mounted welding devices are designed for specific scenarios (such as welding the inner wall of the steel containment vessel in nuclear power plants). The welding torch moves along a preset track, but it can only cover a fixed path and cannot adapt to non-standard welds or spatial changes (such as path deviation caused by equipment deformation). In addition, the equipment installation and commissioning cycle is long (usually 1-2 weeks) and the modification cost is high.

[0007] Limitations: Humans are exposed to radiation and high temperatures, resulting in extremely low efficiency; fixed equipment has poor flexibility and is only suitable for standardized scenarios.

[0008] II. Welding of large outdoor structural components (such as storage tanks, bridges, and ship decks)

[0009] Current solutions primarily rely on manual labor and large-scale specialized equipment.

[0010] Manual welding: For large structures such as storage tanks and bridges, welders use handheld electrode arc welding or CO2 gas shielded welding guns. The daily welding length is usually no more than 50 meters, and defects such as weld beads and lack of fusion are prone to occur in vertical and horizontal welding positions (the pass rate is about 80%-85%).

[0011] Traditional specialized equipment: For flat welding positions of large structural components (such as the top surface of bridge steel box girders), gantry submerged arc welding machines (which require rail fixation) are used, but they can only handle horizontal welds; large-area welding of ship decks may use cantilever automatic welding vehicles, but they require manual pushing and adjustment of position.

[0012] Limitations: Manual operation poses high safety risks, and efficiency is greatly affected by physical strength and weather; traditional equipment relies on tracks or manual propulsion, and has poor adaptability to curved surfaces and irregular structures.

[0013] 3. Complex terrain and all-position welding (such as mountain pipelines, bends, and steep slopes).

[0014] Current solutions primarily rely on a combination of manual on-site operations and semi-automatic equipment assistance.

[0015] All-position welding (such as pipe circumferential welding): relies on the welder's skills and uses manual TIG welding (tungsten inert gas welding) or semi-automatic flux-cored wire welding. It requires the control of the molten pool by "cranking" and "folding" the handle, which requires a high level of welder experience (usually more than 5 years of experience) and cannot be done continuously (a break is required every 40 minutes).

[0016] Limitations: It is greatly restricted by terrain, requires extremely high manual labor intensity, and has poor quality stability.

[0017] IV. Confined spaces and precision welding (such as narrow pipes in nuclear power plants and interiors of ship cabins)

[0018] Existing solutions primarily rely on "manually restricted operations" and "small fixed tools".

[0019] Manual welding: Welders must crouch down in confined spaces (such as pipes with a diameter ≤500mm or double bottom tanks on ships) and use miniature welding torches (such as TIG welding torches with a diameter of 8mm) to work. For example, when connecting pipes in a ship's engine room, welders need to lie on their side or face down. When their vision is obstructed, they can only operate by touch, making it difficult to control the accuracy of the weld (the error is often ≥1mm), and the limited posture can easily lead to missed welds.

[0020] Small fixing tools: For some regular narrow spaces (such as standard diameter pipes), use "internal welding machines" (such as automatic pipe circumferential welding tools), but the equipment needs to be inserted and fixed from one end of the pipe in advance.

[0021] Limitations: Manual operation is limited by space and line of sight, resulting in high quality risks; small tools are only suitable for standardized scenarios, with zero flexibility.

[0022] V. Standardization and mass production (e.g., automobile manufacturing, rail transit steel structures)

[0023] Current solutions primarily involve "fixed robotic arm + manual welding".

[0024] Standardized workpieces: Welding is carried out using a six-axis fixed robotic arm (such as automotive chassis longitudinal beams and standardized steel components). Automated welding is achieved through preset programs and tooling fixtures for positioning. For example, in an automotive factory's body welding line, the robotic arm can complete 90% of the standardized welds, but programming and debugging need to be done 3-5 days in advance, and the tooling fixtures are expensive.

[0025] Non-standard / small batch parts: Relying on manual CO2 gas shielded welding or submerged arc welding, such as irregular nodes in the steel structure industry (such as "cross-shaped" and "T-shaped" steel columns), because they cannot be adapted to robotic arm tooling, they need to be operated manually by welders, which is inefficient (maximum of 5-8 pieces can be completed per day). Furthermore, due to differences in welder techniques, the weld formation consistency is poor (the pass rate of the same batch fluctuates by ±10%).

[0026] Limitations: Fixed robotic arms are only suitable for standardized, mass production and have poor adaptability to small-batch non-standard parts; manual welding is inefficient and of inconsistent quality. Utility Model Content

[0027] The purpose of this invention is to provide a multi-legged wheeled intelligent welding robot to solve the problems mentioned in the background art.

[0028] To achieve the above objectives, this utility model provides the following technical solution: a multi-legged wheeled intelligent welding robot, specifically comprising:

[0029] The body comprises an upper extension shaft, a front lidar, an integrated control system, and multiple hip joint modules at the lower part. The limbs, numbering the same as the hip joint modules, each include a thigh, a knee joint module, a lower leg, and electrically driven wheels. One end of the thigh is connected to the hip joint module and can rotate along its axis. The other end of the thigh is connected to the lower leg via the knee joint module. The lower leg, away from the knee joint module, is fitted with an electrically driven wheel. The welding arm comprises a flexible arm, a welding torch, and a teach-free camera. The flexible arm is mounted on the extension shaft and can move with it. Both the welding torch and the teach-free camera are mounted on the flexible arm.

[0030] Preferably, the number of limbs is eight, and the eight limbs are divided into four symmetrical groups, and the four groups of limbs are evenly distributed along the length of the body at the lower part of the body.

[0031] Preferably, the extension shaft is driven by a linear motor to drive the welding arm to achieve precise forward and backward movements, and the linear motor is installed inside the body.

[0032] Preferably, both the hip joint module and the knee joint module are equipped with drive motors to drive the thigh and calf to rotate, and each joint is independently controlled.

[0033] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0034] 1. Completely avoid high-risk activities and ensure the safety of workers.

[0035] For high-risk scenarios such as nuclear power plants and high-temperature, high-radiation environments, robots can completely replace human workers in dangerous areas, fundamentally solving the risk of personnel exposure to radiation and high temperatures under the "human + simple protection" model. Compared to the limitation of human workers wearing 20-30 kg heavy protective suits and working for no more than 30 minutes at a time, robots can operate continuously for 24 hours without on-site personnel, and can complete high-risk welds with only remote monitoring.

[0036] 2. Adaptive movement across all terrains, overcoming limitations in complex environments.

[0037] Multi-legged wheeled composite mobility, balancing efficiency and flexibility: The combination of 8 legs and electrically driven wheels retains the high efficiency of wheeled mobility on flat ground (such as outdoor storage tanks and bridge flat areas), while the hip and knee joint modules drive the flexion and extension of the legs, making it suitable for complex terrains such as mountain pipelines, steep slopes, and confined spaces.

[0038] 3. Intelligent and precise welding significantly improves weld quality.

[0039] Teaching-free recognition and real-time adjustment eliminate reliance on human experience: The teaching-free camera mounted on the welding arm can automatically scan the workpiece to be welded, extract feature data such as weld bevel edges and gap width, and accurately locate the weld trajectory through the control system's "feature matching" algorithm, without the need for manual pre-programming or teaching. Compared to the limitations of manual welding, which "relies on the experience of welders with more than 5 years of experience," and fixed robotic arms, which "require 3-5 days of pre-programming and debugging," the robot can achieve automatic weld recognition and path planning. During the welding process, the teaching-free camera continuously tracks the weld status and provides real-time feedback on changes in the molten pool. The control system dynamically adjusts parameters such as welding current, voltage, and wire feed speed based on the feedback to avoid defects such as weld beads and incomplete fusion. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the overall structure of the welding robot;

[0041] Figure 2 This is a schematic diagram of a box girder welding scenario;

[0042] Figure 3 This is a schematic diagram of a partition welding scenario;

[0043] Figure 4 This is a schematic diagram of the welding process.

[0044] In the image: 1. Torso; 2. Thigh; 3. Lower leg; 4. Hip joint module; 5. Knee joint module; 6. Electric drive wheel foot; 7. Extended shaft; 8. Flexible arm; 9. Welding torch; 10. Teach-free camera; 11. LiDAR. Detailed Implementation

[0045] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0046] This invention provides a multi-legged wheeled intelligent welding robot, which mainly consists of a body, legs, and a welding arm. The installation method and cooperation logic of each component are as follows:

[0047] 1. Body Part Installation

[0048] The body section forms the core skeleton of the robot. It is made of high-strength metal and processed into a single structure, undertaking the support and positioning functions of all components. The specific installation details are as follows:

[0049] Installation of extension shaft 7: Extension shaft 7 is horizontally installed in the pre-set mounting slot on the upper part of body 1. Extension shaft 7 is driven by a linear motor installed in body 1. Extension shaft 7 is connected to the bottom of flexible arm 8, ensuring that flexible arm 8 can move forward and backward with extension shaft 7, thus expanding the lateral coverage of welding operations.

[0050] LiDAR 11 Installation: The LiDAR is embedded in the front of the body 1 via a bracket, with the lens facing the front and sides of the robot to ensure 360° perception of the surrounding environment; the LiDAR is connected to the robot control system via a data line to perform Simultaneous Localization and Mapping (SLAM), path planning, and obstacle avoidance navigation.

[0051] IMU System Integration: The IMU system is integrated at the center of the body 1. It is connected to the hip joint module 4, knee joint module 5 and control system of the limbs and legs through data lines. It collects posture data such as tilt angle and angular velocity of the robot body in real time, which is used to dynamically adjust the movement of the limb joints and maintain the body balance.

[0052] Hip joint module 4 installation: There are a total of 8 hip joint modules. The 8 hip joint modules are divided into four groups that are symmetrical on the left and right and are evenly distributed along the lower part of the body 1. Each hip joint module 4 is fixed to the body 1. The output shaft of the module is rigidly connected to one end of the thigh 2 of the limb part to provide the thigh with rotational driving force around the hip joint.

[0053] 2. Limb and leg installation

[0054] There are a total of 8 limbs and legs, symmetrically distributed on the lower part of the torso:

[0055] Thigh 2 is connected to hip joint module 4: one end of the thigh is welded to the output shaft of hip joint module 4, and can rotate along the axis of hip joint module. The rotation angle range is based on the principle of "adapting to complex terrain height adjustment" to ensure that the limbs can flex and extend flexibly.

[0056] Knee joint module 5 connection: One end of the knee joint module is fixed to the end of the thigh 2 away from the hip joint module by bolts. The knee joint module 5 has a built-in drive motor, and the output end of the drive motor is connected to the lower leg 3. The knee joint module 5 has the same structure as the hip joint module 4 and can drive the lower leg to rotate along the axis of the knee joint module, so as to realize the coordinated flexion and extension of the thigh 2 and the lower leg 3, and adapt to the height difference of different terrains.

[0057] Electric drive wheel feet 6 installation: The electric drive wheel feet are fixed to the end of the lower leg 3 away from the knee joint module 5 and connected to the lower leg. The electric wheel feet have built-in motors that can drive the wheels to rotate. All 8 electric drive wheel feet are independently controlled and connected to the robot control system through wiring. This enables the robot to move forward, backward, and turn differentially. The forward direction can be adjusted in real time through the differential speed of the wheel feet to improve the stability of movement.

[0058] 3. Welding arm installation

[0059] The welding arm is mounted entirely on the extension shaft 7 of the body 1, serving as the core welding execution unit. Installation details are as follows:

[0060] The flexible arm 8 is fixedly connected to the extension shaft 7, which is driven by a linear motor to ensure that the flexible arm moves smoothly and with the required accuracy for welding.

[0061] Installation of welding torch 9 and teachless camera 10: The welding torch is fixed to the end of the flexible arm 8 by a special clamp. The teachless camera 10 is fixed in parallel with the welding torch by a bracket, with the lens facing the welding direction of the welding torch to ensure that the workpiece to be welded in the welding torch working area can be scanned. The teachless camera 10 is connected to the robot control system through a data line to perform workpiece scanning, weld recognition and real-time feedback of weld status. Its installation position is based on the principle of "unobstructed capture of weld features" and maintains a fixed distance from the welding torch.

[0062] like Figure 4 The working process of this welding robot is as follows:

[0063] Step 1: Environmental Modeling and Path Planning

[0064] After the robot is started, the LiDAR 11 begins to scan the working environment, collecting data such as the location and outline of obstacles (such as equipment supports and protruding structures), the workpiece to be welded, and terrain undulations.

[0065] The lidar transmits environmental data to the control system, and combines it with the body posture data fed back by the IMU system to generate a three-dimensional point cloud map of the working environment through the SLAM algorithm.

[0066] The control system plans the robot's movement path in a 3D map based on the preset "weld seam target" (such as the circumferential weld seam of a nuclear power pipeline or the long weld seam of a ship deck). The path planning is based on the principles of "avoiding obstacles, reaching the work position with the shortest distance, and ensuring the stability of the body" and generates executable movement instructions.

[0067] Step 2: Move to the work location

[0068] The control system sends movement commands to the electric drive wheels 6 of the limbs, and the eight electric drive wheels move in coordination according to the planned path to realize the robot's forward, backward or differential turning.

[0069] During movement, the IMU system collects the posture data of body 1 in real time. If body tilt is detected (such as the tilt angle exceeding the safe range due to terrain slope), adjustment commands are immediately sent to hip joint module 4 and knee joint module 5.

[0070] The hip joint module 4 drives the thigh 2 to rotate around the hip joint, and the knee joint module 5 drives the lower leg 3 to rotate around the knee joint. By adjusting the flexion and extension angles of the eight limbs, the body is dynamically kept horizontal, ensuring no bumps during movement and providing a stable foundation for subsequent welding.

[0071] Step 3: Weld Identification and Location

[0072] After the robot reaches the work position, the control system sends a command to the linear motor of the extended axis 7 to drive the flexible arm 8 to move along the extended axis to the vicinity of the workpiece to be welded.

[0073] The teachless camera 10 is started to scan the surface of the workpiece to be welded and extract the feature data of the weld (such as bevel edge, gap width, and weld trajectory).

[0074] The teachless camera feeds back the weld feature data to the control system. The control system identifies the precise location of the weld (start point, end point, trajectory) through the "feature matching" algorithm, and automatically plans the welding path of the welding torch 9 (such as straight line trajectory or circular arc trajectory) in combination with the working radius of the flexible arm 8. At the same time, the control system presets the initial welding process parameters (current, voltage, wire feed speed) according to the weld type (such as thick plate weld or thin plate weld).

[0075] Step 4: Intelligent Welding

[0076] After welding is started, the welding torch 9 starts welding operation according to the preset process parameters. The teachless camera 10 continuously tracks the position and status of the weld and feeds back the real-time data to the control system. At the same time, the control system adjusts the welding process parameters (such as current and voltage) in real time according to the weld status fed back by the teachless camera (10) to avoid defects such as weld beads and lack of fusion, and ensure the stability of weld quality.

[0077] Step 5: Work completed and reset

[0078] After a single weld is completed, the welding torch 9 stops working, and the flexible arm 8 returns to its initial position along the extension axis 7. The lidar 11 rescans the environment to confirm whether there is another weld to be welded. If there is, steps 1-4 are repeated. If not, the control system plans a return path and controls the electric drive wheels 6 to drive the robot to the preset docking point. After the robot docks, the control system automatically detects the status of each component (such as the welding torch wire balance and wheel wear) to complete one work cycle.

[0079] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-legged wheeled intelligent welding robot, characterized in that: include: The body (1) has an extension shaft (7) on the upper part, a laser radar (11) at the front, an integrated control system, and multiple hip joint modules (4) at the lower part; the limbs are the same number as the hip joint modules (4), each limb includes a thigh (2), a knee joint module (5), a lower leg (3) and an electric drive wheel (6), one end of the thigh (2) is connected to the hip joint module (4) and can rotate along its axis, the other end of the thigh (2) is connected to the lower leg (3) through the knee joint module (5), and the lower leg (3) is equipped with an electric drive wheel (6) at the end away from the knee joint module (5); the welding arm includes a flexible arm (8), a welding torch (9) and a teachless camera (10), the flexible arm (8) is mounted on the extension shaft (7) and can move with the extension shaft (7), the welding torch (9) and the teachless camera (10) are both mounted on the flexible arm (8).

2. The multi-legged wheeled intelligent welding robot according to claim 1, characterized in that: The number of limbs is eight, and the eight limbs are divided into four groups that are symmetrical on the left and right sides. The four groups of limbs are evenly distributed along the length of the body (1) at the lower part of the body (1).

3. The multi-legged wheeled intelligent welding robot according to claim 2, characterized in that: The extension shaft (7) is driven by a linear motor to drive the welding arm to make precise forward and backward movements. The linear motor is installed inside the body (1).

4. The multi-legged wheeled intelligent welding robot according to claim 2, characterized in that: Both the hip joint module (4) and the knee joint module (5) are equipped with drive motors to drive the thigh (2) and the lower leg (3) to rotate, and each joint is independently controlled.

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