Man-machine cooperation valve body assembling platform and assembling method thereof

Abstract

The invention discloses a man-machine cooperation valve body assembly platform which is divided into a material preparation area, a manual operation area, a feeding and discharging station, a robot assembly station, a tightening station, a detection station and a man-machine interaction area, and an annular guide rail used for conveying parts is arranged on the table top of the assembly platform. The invention further discloses an assembling method of the assembling platform. The assembly efficiency is improved while the mounting surfaces of the parts are protected, the problems of unstable product assembly quality, high manual labor intensity and the like in a traditional assembly mode are solved, and the operation cost of an enterprise is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of robot automatic assembly, and in particular to a valve body assembly platform in a human-machine collaborative mode and an assembly method thereof. Background Art

[0002] Currently, aerospace valve bodies generally adopt a discrete assembly model based on manual labor and experience. According to statistics, this assembly work accounts for 20%-70% of the production and manufacturing workload. For typical valve body products, conventional manual discrete assembly includes the following elements: matching, cleaning, and inspecting parts; applying grease; shaft and hole assembly (precision assembly of pistons, springs, and other parts with small gaps between them and the deep holes of the housing); thread assembly (fixed torque tightening assembly of the internal and external threads of the housing); stroke detection, and finished product testing. In shaft and hole assembly, due to the small assembly gap, excessive assembly force can easily damage the part surface, affecting performance; thread assembly has strict requirements on torque accuracy, and manual tightening cannot guarantee assembly quality, affecting product consistency. The development and integration of automated equipment suitable for precision shaft and hole and thread assembly is the key to reforming existing assembly methods.

[0003] Machine vision is the process of capturing images through visual cameras, analyzing them with visual algorithms, and outputting key image data. It is mainly used for precision positioning, identification of presence or classification, and test and measurement. Force-position control is divided into force-position hybrid control and impedance control, which is an effective method for controlling contact operations in complex workspaces. The two technologies mentioned above have been gradually introduced into the field of aerospace assembly, such as docking of aircraft cabins, assembly of satellite surface instruments, and flexible assembly of tanks. At the same time, for the assembly of complex parts, the human-machine collaborative mode combines the stability, efficiency, and high precision of robots with manual experience, which can effectively improve the assembly efficiency and quality of products and meet complex and flexible assembly requirements.

[0004] While machine vision and force-position control technologies have been researched in the precision assembly of complex components, their application in aerospace valve assembly, where human-machine collaboration is crucial, has yet to be applied. Valve bodies are critical components in aerospace engines and booster delivery systems, and are also single points of failure for aerospace equipment. Their manufacturing precision and reliability critically impact the equipment's normal operation. However, aerospace valves generally utilize a discrete assembly model based primarily on manual experience. This results in a low degree of automation in the assembly process, insufficient scale control capabilities, low assembly efficiency, difficulty ensuring quality stability, and high labor intensity for workers, making it difficult to meet the needs of the rapidly developing aerospace industry. Therefore, reforming existing assembly models and researching and applying next-generation automated valve assembly technologies have become inevitable development trends in aerospace valve assembly and manufacturing. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects and provide a human-machine collaborative valve body assembly platform and an assembly method thereof.

[0006] A human-machine collaborative valve body assembly platform, which is divided into a material preparation area, a manual operation area, a loading and unloading station, a robot assembly station, a tightening station, a testing station, and a human-machine interaction area. The table of the assembly platform is provided with a circular guide rail for conveying parts; The material preparation area is provided with a parts tray with identification marks and a visual camera, which is used to collect the identification of the parts tray and the image information of the parts in the tray, and upload them to the collaborative robot controller; The collaborative robot is equipped with an electric gripper at the end and connected to the collaborative robot controller. The collaborative robot controller is used to process image information for feature extraction, identify part position information, detect whether the parts are fully aligned, and reverse-analyze the gripping posture to control the collaborative robot's loading and unloading. The end of the industrial robot is connected to a force sensor and a pneumatic gripper, and is also connected to an industrial robot controller. The force sensor is used to collect real-time contact force data of the pneumatic gripper during the assembly process and upload it to the industrial robot controller. The industrial robot controller is used to compare the contact force collected by the force sensor with the expected force to obtain a position correction value, and adjust the position of the industrial robot in real time to perform assembly within the preset contact force. The inspection station is equipped with a stroke detection cylinder to detect the piston stroke of the assembled parts and upload the data to the operation terminal; The operation terminal is located in the manual operation area and is used to interact with the collaborative robot controller, industrial robot controller, stroke detection cylinder and visual camera for data.

[0007] As a preferred method, the tightening station is provided with a tightening device, which includes a cylinder, a pneumatic clamp, and an electric tightening tool. The electric tightening tool is driven to rise and fall by the cylinder and guided by a guide rail slider. The output end of the electric tightening tool is connected to a special sleeve for the valve body. The pneumatic clamp is connected to the cylinder for clamping parts during the tightening process.

[0008] As a preferred method, the identification mark is used to assist in locating the part tray area to establish a coordinate system and obtain the part tray ID to verify that the tray is complete.

[0009] As a preferred approach, the industrial robot controller adopts a force-position hybrid control strategy that combines inner-loop position control with outer-loop impedance control.

[0010] As a preferred method, the human-machine interaction area is equipped with interactive tooling, which is used for temporarily storing parts after manual completion of part of the assembly process for the non-standard structure of the valve body, waiting to be picked up by the collaborative robot.

[0011] The present application also discloses an assembly method of a human-machine collaborative valve body assembly platform, comprising the following steps: S1: The visual camera collects the part tray identification mark and part image. The collaborative robot controller verifies the completeness of the parts and calculates the gripping posture based on the collected information, guiding the collaborative robot and electric gripper to load the parts to the interactive tooling. S2: Human operators use the operating terminal to confirm the completeness of parts and the assembly process in the manual operation area. After completing part inspection and oiling in the human-machine interaction area, the collaborative robot transfers the parts to the loading and unloading station. S3. The circular guide rail transports the parts to the robot assembly station, and the industrial robot assembles the parts and performs pre-tightening under the control of the industrial robot controller; S4. The parts are transported to the tightening station, clamped by pneumatic clamps, and tightened by electric tightening tools; S5. The part is transported to the inspection station, and the stroke detection cylinder measures the piston stroke of the part and uploads the data to the operation terminal; S6. The parts are transported to the loading and unloading station, and the collaborative robot picks up the parts and unloads them to complete the assembly.

[0012] As a preferred method, in step S3, the industrial robot assembles parts in sequence according to the process, the force sensor provides real-time feedback of the contact force of the pneumatic gripper during the assembly action, and the industrial robot controller corrects the industrial robot's action position based on the difference between the feedback data and the expected force.

[0013] The present invention has the following advantages: 1) Reduced labor intensity: In traditional valve assembly, all assembly processes are completed manually, which requires long hours and high labor intensity. Collaborative robots, industrial robots, and electric tightening tools replace manual labor in many assembly processes. Manual labor only needs to complete a small amount of preparatory work to easily complete valve assembly, significantly reducing labor intensity. 2) Improve the stability of valve body assembly quality: The valve body parts assembly process is completed by industrial robots and electric tightening. After debugging, the equipment movement is precisely controlled by the controller, with repeatability higher than manual experience. The entire assembly process is managed and controlled by software, which significantly reduces the assembly error rate compared to the original manual experience assembly. 3) Improve production efficiency: By introducing automated equipment for assembly, the proportion of manual assembly processes is reduced, and different assembly processes are carried out simultaneously, making the production process more coherent. According to calculations, production efficiency can be increased by approximately 30% compared to the original production model; 4) Good adaptability: No new factory buildings or production lines are required, and the location of existing machine tools does not need to be changed. It is applicable to common milling machine tools with group manufacturing layout modes that are prevalent in manufacturing enterprises as long as the AGV path movement requirements and the power arm motion range requirements are met. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the layout of the present invention; Figure 2 This is a schematic diagram of the assembly platform; Figure 3 Schematic diagram of the tightening device structure.

[0015] In the figure: 1-Material preparation area, 2-Manual operation area, 3-Loading and unloading station, 4-Inspection station, 5-Tightening station, 6-Robot assembly station, 7-Human-machine interaction area, 8-Visual camera, 9-Collaborative robot, 10-Electric gripper, 11-Parts tray, 12-Operation terminal, 13-Platform, 14-Interactive tooling, 15-Stroke detection cylinder, 16-Annular guide rail, 17-Collaborative robot controller, 18-Industrial robot controller, 19-Pneumatic gripper, 20-Force sensor, 21-Industrial robot, 22-Cylinder, 23-Electric tightening tool, 24-Guide rail slider, 25-Special sleeve, 26-Pneumatic clamp, 27-Rodless cylinder. DETAILED DESCRIPTION

[0016] To facilitate understanding of the technical means, creative features, objectives, and effects achieved by the present invention, the following examples are provided to provide a detailed description of the present invention. It should be noted that the examples are intended only to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Persons skilled in the art may make non-essential improvements and adjustments based on the present invention.

[0017] like Figure 1-Figure 3 As shown, a human-machine collaborative valve body assembly platform is provided, wherein the assembly platform is divided into a material preparation area (1), a manual operation area (2), a loading and unloading station (3), a detection station (4), a tightening station (5), a robot assembly station (6), and a human-machine interaction area (7). The collaborative robot (9) is installed at the intersection of the material preparation area (1), the human-machine interaction area (7), and the loading and unloading station (3), and the industrial robot (21) is installed at the intersection of the robot assembly station (6) and the tightening station (5). The number of robot assembly stations (6) increases or decreases according to the type of valve body. The main equipment of the assembly platform includes visual camera (8), collaborative robot (9), electric gripper (10), parts tray (11), operation terminal (12), platform (13), interactive tooling (14), stroke detection cylinder (15), circular guide rail (16), collaborative robot controller (17), industrial robot controller (18), pneumatic gripper (19), force sensor (20), and industrial robot (21). The assembly station equipment is composed of Figure 3 As shown, it includes a cylinder (22), an electric tightening tool (23), a guide rail slider (24), a special sleeve (25), a pneumatic clamp (26), and a rodless cylinder (27). The electrical equipment communicates with the I / O via the TCP / IP protocol for data exchange.

[0018] The platform (13) is constructed of aluminum profiles with a supporting structure and is used to install and store the electrical equipment and separate the working area of ​​the industrial robot (21); The visual camera (8) is mounted on a bracket of a platform (13) of the material preparation area (1) by screws, and is used to collect Aruco marking points on the parts tray (11) and image information of the parts in the tray, and upload the information to the collaborative robot controller (17); the parts tray (11) is mounted on the material preparation area (1) by screws, and the parts tray is engraved with Aruco marking points, and is used to store valve body parts and collect images by the visual camera (8); The collaborative robot controller (17) is installed in the platform (13), processes image information to extract features, identifies part position information, detects whether the parts are complete, and reversely analyzes the grasping posture to control the collaborative robot (9) to load and unload materials to the interactive tooling (14).

[0019] The end of the collaborative robot (9) is connected to the electric gripper (10) via a dedicated interface, receives position information sent by the collaborative robot controller (17), and grasps and places parts; The interactive tooling (14) is designed for non-standard valve body structures and is used to temporarily store parts after manual assembly processes are completed, waiting for the collaborative robot (9) to pick them up; The end of the industrial robot (21) is connected to the force sensor (20) and the pneumatic gripper (19) through a non-standard adapter, receives the position information sent by the industrial robot controller (18), and completes the assembly of the parts and pre-tightening of the thread by one turn while controlling the actual contact force and torque within the preset values; The force sensor (20) collects the force and torque data during the assembly process in real time and uploads it to the industrial robot controller (18); The industrial robot controller (18) is installed in the platform (13), and compares the collected contact force with the expected force to obtain a position correction value. The inner loop of the control system is controlled based on the corrected expected position, and the outer loop uses an impedance controller to form a force-position hybrid control, and adjusts the posture of the industrial robot (21) in real time. The assembly is performed within the preset contact force to protect the valve body shaft hole matching surface; The tightening station (5) completes the torque tightening of the valve body thread. The pneumatic clamp (26) is installed on the rodless cylinder (27) to clamp and fix the valve body parts. The electric tightening tool (23) is selected according to the valve body tightening process requirements and is installed on the guide rail slider (24). It is raised and lowered by the cylinder (22). The end is equipped with a special sleeve (25) for the valve body parts, which is customized according to the shape of the tightening parts. The operation terminal (12) is placed in the manual operation area (2) and is installed with control software to monitor the working status of the entire electrical equipment and manage the assembly process flow; An assembly method for a human-machine collaborative valve body assembly platform comprises the following steps: 1) The visual camera (8) collects and uploads the Aruco logo and part image on the part tray (11) in real time. The collaborative robot controller (17) uses the Aruco marker to assist in locating the part tray area to establish a coordinate system and obtain the part tray ID to verify the completeness of the tray. It identifies whether a part is placed at that location and calculates the grasping posture of the part. At the same time, it completes the task completeness detection based on the part inspection results and guides the collaborative robot (9) and the electric gripper (10) to load the material to the interactive tooling (14); 2) The operator confirms the completeness of parts and the assembly process through the operation terminal (12) in the manual operation area (2), completes the parts inspection, oiling and other processes in the human-machine interaction area (7), and the collaborative robot (9) picks up the parts and takes them to the loading and unloading station (3); 3) The annular guide rail (16) is installed in the platform (13). Multiple sets of non-standard fixtures are installed on the guide rail to place the parts to be assembled. They are used for the logistics transportation of parts in the loading and unloading station (3), the robot assembly station (6), the inspection station (4), etc. The specific number of stations is determined according to the assembly process of the valve body. The industrial robot (21) assembles the parts in sequence according to the process. The force sensor (20) provides real-time feedback on the contact force of the pneumatic gripper (19) during the assembly action. The industrial robot controller (18) corrects the action position of the industrial robot (21) according to the difference between the feedback force and the expected force, completing the assembly of the parts and pre-tightening of the thread by one turn. 4) The industrial robot (21) transfers the part to be tightened to the tightening station (5), the pneumatic clamp (26) clamps the part, the rodless cylinder (27) moves in, the cylinder (22) descends, and the electric tightening tool (23) tightens the part according to the preset torque; the rodless cylinder (27) moves out; 5) The circular track (16) transports the parts to the inspection station (4), and the stroke detection cylinder (15) is installed at the inspection station (4) through a bracket to detect the piston movement stroke of the valve body finished product and upload the data to the operation terminal (12); 6) The parts are transported to the loading and unloading station (3). The collaborative robot (9) picks up the finished product and completes the assembly. The operation terminal (12) monitors and manages all assembly process flows and electrical equipment status.

[0020] The number of robot assembly stations (6) of the annular guide rail (16) is increased or decreased according to the specific assembly process of different valve bodies, and assembly actuators are added.

Claims

1. A human-machine collaborative valve body assembly platform, characterized by: The assembly platform is divided into a material preparation area, a manual operation area, a loading and unloading station, a robot assembly station, a tightening station, a testing station, and a human-machine interaction area. The table of the assembly platform is provided with a circular guide rail for conveying parts. The material preparation area is provided with a parts tray with identification marks and a visual camera, which is used to collect the identification of the parts tray and the image information of the parts in the tray, and upload them to the collaborative robot controller; The collaborative robot is equipped with an electric gripper at the end and connected to the collaborative robot controller. The collaborative robot controller is used to process image information for feature extraction, identify part position information, detect whether the parts are fully aligned, and reverse-analyze the gripping posture to control the collaborative robot's loading and unloading. The end of the industrial robot is connected to a force sensor and a pneumatic gripper, and is also connected to an industrial robot controller. The force sensor is used to collect real-time contact force data of the pneumatic gripper during the assembly process and upload it to the industrial robot controller. The industrial robot controller is used to compare the contact force collected by the force sensor with the expected force to obtain a position correction value, and adjust the position of the industrial robot in real time to perform assembly within the preset contact force. The inspection station is equipped with a stroke detection cylinder to detect the piston stroke of the assembled parts and upload the data to the operation terminal; The operation terminal is located in the manual operation area and is used to interact with the collaborative robot controller, industrial robot controller, stroke detection cylinder and visual camera for data.

2. The human-machine collaborative valve body assembly platform according to claim 1, characterized in that: The tightening station is provided with a tightening device, which includes a cylinder, a pneumatic clamp, and an electric tightening tool. The electric tightening tool is driven to rise and fall by the cylinder and guided by a guide rail slider. The output end of the electric tightening tool is connected to a special sleeve for the valve body. The pneumatic clamp is connected to the cylinder for clamping parts during the tightening process.

3. The human-machine collaborative valve body assembly platform according to claim 1, characterized in that: The identification mark is used to assist in locating the part tray area to establish a coordinate system and obtain the part tray ID to verify that the tray is complete.

4. The human-machine collaborative valve body assembly platform according to claim 1, characterized in that: The industrial robot controller adopts a force-position hybrid control strategy combining inner-loop position control with outer-loop impedance control.

5. The human-machine collaborative valve body assembly platform according to claim 1, characterized in that: The human-machine interaction area is equipped with interactive tooling, which is used for the non-standard structure of the valve body to temporarily store parts after manual completion of some assembly processes, waiting to be picked up by the collaborative robot.

6. An assembly method using the human-machine collaborative valve body assembly platform according to any one of claims 1 to 5, characterized in that: The steps include: S1: The visual camera collects the part tray identification mark and part image. The collaborative robot controller verifies the completeness of the parts and calculates the gripping posture based on the collected information, guiding the collaborative robot and electric gripper to load the parts to the interactive tooling. S2: Human operators use the operating terminal to confirm the completeness of parts and the assembly process in the manual operation area. After completing part inspection and oiling in the human-machine interaction area, the collaborative robot transfers the parts to the loading and unloading station. S3. The circular guide rail transports the parts to the robot assembly station, and the industrial robot assembles the parts and performs pre-tightening under the control of the industrial robot controller; S4. The parts are transported to the tightening station, clamped by pneumatic clamps, and tightened by electric tightening tools; S5. The part is transported to the inspection station, and the stroke detection cylinder measures the piston stroke of the part and uploads the data to the operation terminal; S6. The parts are transported to the loading and unloading station, and the collaborative robot picks up the parts and unloads them to complete the assembly.

7. The assembly method according to claim 6, characterized in that: In step S3, the industrial robot assembles parts in sequence according to the process, and the force sensor provides real-time feedback of the contact force of the pneumatic gripper during the assembly action. The industrial robot controller corrects the action position of the industrial robot based on the difference between the feedback data and the expected force.

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