A robotic arm for assembling car doors

Abstract

This invention relates to the field of automotive door assembly technology and discloses an automotive door assembly robot. The robot includes a fixed base, a first arm assembly driven to the top of the fixed base, and a second arm assembly driven to the bottom of the first arm assembly away from the fixed base. An adaptive gripper is installed at the end of the robot for gripping a car door. It also includes a vision positioning unit for identifying the predetermined position of a vehicle on the assembly line. By accurately identifying the vehicle position through the vision positioning unit and combining it with a pre-learned teaching path, the predictive control unit can control the robot to autonomously perform most assembly actions, achieving predictive autonomous operation "before" manual operation. This frees the operator from repetitive handling labor, allowing them to focus more on final precise alignment and quality confirmation, thereby greatly improving the production cycle time of a single workstation and the overall assembly efficiency.

Description

Technical Field

[0001] This invention relates to the field of automotive door assembly technology, specifically to an automotive door assembly robot. Background Technology

[0002] In modern automobile manufacturing, the assembly of car doors is a crucial process. Car doors are characterized by their large size, heavy weight, and irregular shape. Traditional manual handling and installation methods are not only extremely labor-intensive and require high physical strength from the operators, but also inefficient. Fatigue can easily lead to decreased installation accuracy or damage to the car door and body.

[0003] To address these issues, industrial robots have been introduced onto assembly lines. However, while traditional fully automated industrial robots have solved the load and precision problems, they also have their limitations. First, fully automated robots are complex to program. For multi-model production lines, complex driver programs need to be written and debugged for each model, which is not only time-consuming and labor-intensive but also results in poor flexibility when switching production lines. Second, robots lack human perception and judgment, making it difficult for them to respond as flexibly as humans when dealing with subtle positional deviations or unexpected situations. Summary of the Invention

[0004] This invention provides a robotic arm for assembling automobile doors, which solves the problems mentioned in the background art.

[0005] The present invention provides the following technical solution: a car door assembly robot, the robot including a fixed base, a first arm assembly driven to the top of the fixed base, and a second arm assembly driven to the bottom of the first arm assembly away from the fixed base.

[0006] An adaptive gripper, mounted on the end of the robotic arm, is used to grasp a car door;

[0007] It also includes a visual positioning unit for identifying the predetermined position of vehicles on the assembly line.

[0008] As a preferred technical solution of the present invention: the fixed base includes a support base, a rotating platform is fixedly mounted on the top of the support base, a support rod is rotatably connected to the top of the rotating platform, a first angle detection disk is fixedly mounted on the top outer wall of the rotating platform, a fixed platform is fixedly mounted on the bottom outer wall of the support rod, a linear driver is rotatably connected to the top of the fixed platform, a first angle sensor is fixedly mounted on the outer wall of the fixed platform away from the linear driver, a main controller is fixedly mounted on the outer wall of the support rod, support frames are fixedly mounted on both sides of the top of the support rod, a top plate is fixedly mounted on the top of the two sets of support frames, a first connecting rod and a second connecting rod are rotatably connected to the inner walls of the two sets of support frames respectively, the end of the second connecting rod near the linear driver is rotatably connected to the top telescopic end of the linear driver, a crossbar is provided on the outer wall of the first connecting rod and the second connecting rod away from the linear driver, and the outer walls of the first connecting rod and the second connecting rod are rotatably connected to the ends of the crossbar respectively;

[0009] The bottom cavity of the support rod is inlaid with a servo motor, and the support rod is fixedly assembled to the rotating platform through the output end of the servo motor. The main controller is electrically connected to the servo motor, the linear driver, and the first angle sensor respectively. The measuring end of the first angle sensor corresponds to the outer wall of the first angle detection disk.

[0010] As a preferred technical solution of the present invention: the first arm assembly includes a second arm housing, a first rotary drive component is fixedly mounted on the top inner wall of the second arm housing, a second position angle sensor is fixedly mounted on the outer wall of the second arm housing, a connecting shaft is fixedly mounted on the top output end of the first rotary drive component, a second angle detection disk is fixedly mounted on the bottom outer wall of the connecting shaft, and a second arm rod is fixedly mounted on the top of the connecting shaft.

[0011] The second arm has a second rotary drive component embedded in the inner cavity of the end away from the second arm housing. A third position angle sensor is fixedly mounted on the outer wall of the end of the second arm away from the second arm housing. The measuring end of the second position angle sensor corresponds to the outer wall of the second angle detection disk. The inner wall of the second arm housing is rotatably connected to the ends of the first connecting rod and the second connecting rod, respectively.

[0012] As a preferred technical solution of the present invention: the second arm assembly includes a third arm, a secondary controller is fixedly mounted on the outer wall of the third arm, control buttons are fixedly mounted on both sides of the bottom of the third arm, a handle is fixedly mounted on the bottom outer wall of the third arm, and a third angle detection disk is fixedly mounted on the top of the third arm.

[0013] The outer wall of the third angle detection disk corresponds to the measuring end of the third position angle sensor. The top of the third arm and the output end of the second rotation drive are fixedly assembled. The sub-controller and control button are electrically connected to the main controller.

[0014] As a preferred technical solution of the present invention: the adaptive clamp includes a clamp frame, an installation base is fixedly mounted on the inner wall of the clamp frame, at least one set of suction cup assemblies is fixedly mounted on the end of the installation base, a connecting frame is fixedly mounted on the inner wall of the suction cup assembly, an adaptive contour support module is fixedly mounted on the bottom of the connecting frame, a suction cup frame is fixedly mounted on the top of the connecting frame, and suction cup bodies are fixedly mounted on both ends of the suction cup frame.

[0015] The gas connection end of the suction cup body is connected to the negative pressure device through a hose, and the hose is fixed to the outer wall of the fixed base, the first arm assembly, and the second arm assembly. The adaptive contour support module and the negative pressure device are both electrically connected to the main controller and controlled by the control button.

[0016] As a preferred technical solution of the present invention: the adaptive contour support module includes a support base, and a plurality of telescopic support probes are fixedly assembled on the outer wall of the support base;

[0017] Several of the telescopic support probes are electrically connected to the main controller.

[0018] As a preferred embodiment of the present invention, the main controller further includes:

[0019] The path learning unit is used to respond to the movement of the robot hand under manual dragging and to record the motion data of each joint of the robot hand to form a teaching path;

[0020] A predictive control unit, connected to the visual positioning unit and the path learning unit, is used to predict and autonomously control the robotic arm to perform the door assembly action by combining the predetermined position of the vehicle with the taught path; and

[0021] The force control coordination unit is used to monitor the external force applied to the robot arm during the autonomous assembly process, and to suspend the autonomous execution of the robot arm when the external force exceeds a preset threshold.

[0022] As a preferred technical solution of the present invention: a force sensor is provided at the end of the handle. The force sensor is used to detect the external force applied by the operator when the robot arm is running automatically and the operator performs a manual emergency stop.

[0023] The present invention has the following beneficial effects:

[0024] The car door is equipped with a robotic arm. By setting up force sensors and handles, the operator can intuitively and easily guide the robotic arm, which carries the heavy car door, to complete complex spatial movements by manually dragging it. At the same time, the path learning unit can automatically record the process, laying the foundation for subsequent automated operation.

[0025] By accurately identifying the vehicle's position through the visual positioning unit and combining it with the pre-learned teaching path, the predictive control unit can control the robotic arm to autonomously perform most of the assembly actions, achieving predictive autonomous operation "before" human intervention. This frees the operator from repetitive handling labor, allowing them to focus more on the final fine alignment and quality confirmation, thereby greatly improving the production cycle time of a single workstation and the overall assembly efficiency.

[0026] The adaptive contour support module can automatically conform to the complex bottom contour of different car door models through multiple independently movable support units, solving the problem that traditional fixed fixtures cannot be compatible with multiple car models, avoiding downtime losses due to frequent tooling changes, and improving the stability of the transportation process through more stable support, thus ensuring subsequent precise assembly. At the same time, when gripping the car door, the main controller can control the adaptive contour support module to restore the real-time posture data of the "standard gripping posture reference". The operator can use the extended positions of several telescopic support probes in their original state as data reference points to directly conform to the outer wall of the end of the car door near the door limiter, realizing rapid positioning between the adaptive contour support module and the car door. Attached Figure Description

[0027] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0028] Figure 2 This is a schematic diagram of the second arm assembly structure of the present invention;

[0029] Figure 3 This is a schematic diagram of the fixed base structure of the present invention;

[0030] Figure 4 This is a schematic diagram of the first arm assembly structure of the present invention;

[0031] Figure 5 This is a schematic diagram of the second arm assembly of the present invention from another perspective;

[0032] Figure 6 This is a schematic diagram of the adaptive clamp structure of the present invention;

[0033] Figure 7 This is a schematic diagram of the adaptive contour support module structure of the present invention.

[0034] In the diagram: 1. Fixed base; 2. First arm assembly; 3. Second arm assembly; 4. Adaptive clamp; 5. Door;

[0035] 101. Support base; 102. Rotating platform; 103. First angle detection disk; 104. Support rod; 105. Fixed platform; 106. Linear driver; 107. First angle sensor; 108. Main controller; 109. Support frame; 110. Top plate; 111. First connecting rod; 112. Second connecting rod; 113. Crossbar;

[0036] 201. Second arm housing; 202. First rotary drive component; 203. Second position angle sensor; 204. Connecting shaft; 205. Second angle detection disk; 206. Second arm rod; 207. Second rotary drive component; 208. Third position angle sensor;

[0037] 301. Third boom; 302. Secondary controller; 303. Control button; 304. Handle; 305. Third angle detection panel;

[0038] 401. Fixture frame; 402. Mounting base; 403. Suction cup assembly; 404. Connecting frame; 405. Adaptive contour support module; 406. Suction cup holder; 407. Suction cup body;

[0039] 4051, Support base; 4052, Telescopic support probe. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Please see Figure 1 - Figure 7 A car door assembly robot includes a fixed base 1, a first arm assembly 2 is driven connected to the top of the fixed base 1, and a second arm assembly 3 is driven connected to the bottom of the first arm assembly 2 away from the fixed base 1.

[0042] An adaptive gripper 4 is installed at the end of the robotic arm for gripping the car door 5;

[0043] It also includes a visual positioning unit for identifying the predetermined position of vehicles on the assembly line.

[0044] In this embodiment, the visual positioning unit may be a 3D industrial camera (not shown) installed above the production line or on the robot arm mounting base 1.

[0045] When the vehicle (not shown in the figure) arrives at the assembly station, the camera takes a picture of the side of the vehicle and uses an image recognition algorithm to locate the three-dimensional spatial coordinates of the body hinge hole and door lock mounting position for installing the door 5, and sends the coordinates as the predetermined position of the vehicle to the main controller 108.

[0046] In a preferred embodiment: the fixed base 1 includes a support base 101, a rotating platform 102 is fixedly mounted on the top of the support base 101, a support rod 104 is rotatably connected to the top of the rotating platform 102, a first angle detection disk 103 is fixedly mounted on the top outer wall of the rotating platform 102, a fixed platform 105 is fixedly mounted on the bottom outer wall of the support rod 104, a linear actuator 106 is rotatably connected to the top of the fixed platform 105, a first angle sensor 107 is fixedly mounted on the outer wall of the fixed platform 105 away from the linear actuator 106, and a support rod 104 is fixedly mounted on the outer wall of the support rod 104. The main controller 108 has support frames 109 fixedly mounted on both sides of the top of the support rod 104. The top of the two sets of support frames 109 is fixedly mounted on the top of the top plate 110. The inner walls of the two sets of support frames 109 are respectively rotatably connected to the first connecting rod 111 and the second connecting rod 112. The end of the second connecting rod 112 near the linear driver 106 is rotatably connected to the top telescopic end of the linear driver 106. The outer wall of the first connecting rod 111 and the second connecting rod 112 away from the linear driver 106 is provided with a crossbar 113, and the outer walls of the first connecting rod 111 and the second connecting rod 112 are respectively rotatably connected to the end of the crossbar 113.

[0047] A servo motor is embedded in the bottom cavity of the support rod 104, and the support rod 104 is fixedly assembled with the rotating platform 102 through the output end of the servo motor. The main controller 108 is electrically connected to the servo motor, the linear driver 106, and the first angle sensor 107 respectively. The measuring end of the first angle sensor 107 corresponds to the outer wall of the first angle detection disk 103.

[0048] In the above structure, the support rod 104 is fixedly assembled with the rotating platform 102 through the output end of the servo motor, so that the servo motor drives the support rod 104 to rotate relative to the rotating platform 102. The measuring end of the first angle sensor 107 corresponds to the outer wall of the first angle detection disk 103, so that the angle of relative rotation between the rotating platform 102 and the first angle detection disk 103 can be measured.

[0049] The rotation between the rotating platform 102 and the support rod 104 enables the first connecting rod 111, the second connecting rod 112, and the connected first arm assembly 2 and second arm assembly 3 located at the end of the support rod 104 to rotate around the rotating platform 102. This allows the adaptive clamp 4 to move over a wide range after adsorbing the car door 5, supported by the fixed base 1, the first arm assembly 2, and the second arm assembly 3, thereby reducing the difficulty of manually assembling the car door 5.

[0050] The first link 111 and the second link 112 are rotatably connected to the support frame 109, and the first link 111 and the second link 112 are further limited by the crossbar 113. The crossbar 113 and the rotation point formed between the support frame 109 and the first link 111 and the second link 112 form a rectangle. When the linear actuator 106 drives the second link 112 to rotate around the rotation axis between the support frame 109 and the second link 112, the first arm assembly 2 located at the ends of the first link 111 and the second link 112 can also move up and down accordingly. At the same time, the rotation point between the first link 111, the second link 112 and the first arm assembly 2 forms a rectangle with the rotation point formed between the support frame 109 and the first link 111 and the second link 112, thereby achieving parallelism between the first arm assembly 2 and the fixed base 1 and preventing the first arm assembly 2 from tilting.

[0051] In a preferred embodiment: the first arm assembly 2 includes a second arm housing 201, a first rotation drive 202 is fixedly mounted on the top inner wall of the second arm housing 201, a second position angle sensor 203 is fixedly mounted on the outer wall of the second arm housing 201, a connecting shaft 204 is fixedly mounted on the top output end of the first rotation drive 202, a second angle detection disk 205 is fixedly mounted on the bottom outer wall of the connecting shaft 204, and a second arm rod 206 is fixedly mounted on the top of the connecting shaft 204;

[0052] The second arm 206 has a second rotary drive 207 embedded in the inner cavity of the end away from the second arm housing 201. The third position angle sensor 208 is fixedly mounted on the outer wall of the end of the second arm 206 away from the second arm housing 201. The measuring end of the second position angle sensor 203 corresponds to the outer wall of the second angle detection disk 205. The inner wall of the second arm housing 201 is rotatably connected to the ends of the first connecting rod 111 and the second connecting rod 112, respectively.

[0053] In the above structure, the second arm housing 201 is connected to the first connecting rod 111 and the second connecting rod 112. The first rotary drive 202 drives the connecting shaft 204 to rotate, and the second arm 206 and the second arm housing 201 rotate relative to each other. The measuring end of the second position angle sensor 203 corresponds to the outer wall of the second angle detection disk 205 to measure the angle of relative rotation between the second arm housing 201 and the second arm 206.

[0054] The rotation between the second arm housing 201 and the second arm rod 206 allows the straight distance between the second arm assembly 3 at the end of the second arm rod 206 and the fixed base 1 to be changed by the rotation angle between the first arm assembly 2 and the fixed base 1. This enables the second arm assembly 3 to move the door 5 more flexibly through the adaptive clamp 4.

[0055] In a preferred embodiment: the second arm assembly 3 includes a third arm 301, a secondary controller 302 is fixedly mounted on the outer wall of the third arm 301, control buttons 303 are fixedly mounted on both sides of the bottom of the third arm 301, a handle 304 is fixedly mounted on the bottom outer wall of the third arm 301, and a third angle detection disc 305 is fixedly mounted on the top of the third arm 301.

[0056] The outer wall of the third angle detection disk 305 corresponds to the measuring end of the third position angle sensor 208. The top of the third arm 301 and the output end of the second rotation drive 207 are fixedly assembled. The auxiliary controller 302, the control button 303 and the main controller 108 are electrically connected.

[0057] In the above structure, the third arm 301 is rotatably connected to the second arm 206 via the second rotary drive 207, thereby enabling the second arm assembly 3 to drive the door 5 to rotate around the axis of the second rotary drive 207 via the adaptive clamp 4, thus achieving position adjustment of the door 5 during assembly. Correspondingly, during operation, the operator controls the movement of the second arm assembly 3 by holding the handle 304, thereby driving the first arm assembly 2 and the fixed base 1 to operate, thereby enabling the door 5 to be moved to the vehicle body for installation under the adsorption support of the equipment. During this process, the corresponding movement data between the fixed base 1, the first arm assembly 2, and the second arm assembly 3 are all collected and recorded.

[0058] In a preferred embodiment: the adaptive clamp 4 includes a clamp frame 401, a mounting base 402 is fixedly mounted on the inner wall of the clamp frame 401, at least one set of suction cup assemblies 403 is fixedly mounted on the end of the mounting base 402, a connecting frame 404 is fixedly mounted on the inner wall of the suction cup assembly 403, an adaptive contour support module 405 is fixedly mounted on the bottom of the connecting frame 404, a suction cup frame 406 is fixedly mounted on the top of the connecting frame 404, and suction cup bodies 407 are fixedly mounted on both ends of the suction cup frame 406.

[0059] The gas connection end of the suction cup body 407 is connected to the negative pressure device through a hose, and the hose is fixed to the outer wall of the fixed base 1, the first arm assembly 2, and the second arm assembly 3. The adaptive contour support module 405 and the negative pressure device are both electrically connected to the main controller 108 and controlled by the control button 303.

[0060] In the above structure, the gas connection end of the suction cup body 407 is connected to the negative pressure device through a hose. The operator controls the connection between the negative pressure device and the suction cup body 407 by controlling the control button 303. In actual use, by attaching the suction cup body 407 to the glass on the car door 5, the operator controls the control button 303 to provide negative pressure to the suction cup body 407, causing the suction cup body 407 to adhere to the glass under negative pressure, thereby fixing the car door 5. The adaptive contour support module 405 located at the bottom of the suction cup body 407 supports the bottom of the car door 5, preventing the car door 5 from directly contacting the device. At the same time, by collecting the data of the contact between the adaptive contour support module 405 and the car door 5, the relative position between the suction cup body 407, the adaptive contour support module 405 and the car door 5 can be collected.

[0061] In a preferred embodiment: the adaptive contour support module 405 includes a support base 4051, and a plurality of telescopic support probes 4052 are fixedly mounted on the outer wall of the support base 4051.

[0062] Several telescopic support probes 4052 are electrically connected to the main controller 108.

[0063] In the above structure, several telescopic support probes 4052 abut against the car door 5, so that some telescopic support probes 4052 are in their original state, while other telescopic support probes 4052 are abutted against by the car door 5, achieving different degrees of contraction. By using the telescopic support probes 4052 in their original state as data base points and verifying the data of the other telescopic support probes 4052 that are abutted against by the car door 5 and achieve different degrees of contraction, the position acquisition and determination between the adaptive fixture 4 and the car door 5 can be realized.

[0064] The main controller 108 is electrically connected to the first rotation drive 202 and the second position angle sensor 203 in the first arm assembly 2, and the second rotation drive 207 and the third position angle sensor 208 in the second arm 206, so as to send control commands and receive status feedback.

[0065] In a preferred embodiment, the main controller 108 further includes:

[0066] The path learning unit is used to respond to the movement of the robot hand under manual dragging and to record the motion data of each joint of the robot hand to form a teaching path;

[0067] A predictive control unit, connected to the visual positioning unit and the path learning unit, is used to predict and autonomously control the robotic arm to perform the assembly action of door 5 by combining the predetermined position of the vehicle with the taught path; and

[0068] The force control coordination unit is used to monitor the external force applied to the robot arm during the autonomous assembly process, and to suspend the autonomous execution of the robot arm when the external force exceeds a preset threshold.

[0069] The main controller 108 also integrates a path learning unit. In teaching mode, when the operator drags the robot, the main controller 108 will collect and record the readings of the first angle sensor 107, the second angle sensor 203, and the third angle sensor 208 in the robot at a preset frequency in real time (i.e., the motion data of each joint), forming a time series data point set containing spatial position and attitude information. This set constitutes the teaching path.

[0070] Specifically, upon receiving the instruction to begin teaching, the unit creates a data logging task. This task is executed cyclically at a preset high frequency (e.g., 100Hz). In each cycle, it sequentially reads the encoder values ​​of all joints of the robotic arm (e.g., joints driven by servo motors, the first rotary drive 202, the second rotary drive 207, etc.). The values ​​represent the precise angle or position of each joint. The acquired data is organized into a data frame, the structure of which can be [timestamp, joint 1 position, joint 2 position, ..., joint N position]. All data frames are stored sequentially, forming a time-series array. At the end of teaching, this array can be selectively processed by a filtering algorithm (e.g., Kalman filtering) to eliminate minor jitters that may be caused by manual dragging, and then saved together with the "standard gripping posture reference" as a teaching path file associated with a specific vehicle model.

[0071] The main controller 108 also integrates a predictive control unit. The predictive control unit receives the vehicle's predetermined position (target coordinate system) provided by the visual positioning unit and calls the teaching path (relative motion trajectory) stored in the path learning unit. Through a coordinate system transformation algorithm, the teaching path is superimposed on the vehicle's actual predetermined position to generate an autonomous running trajectory in absolute coordinates, and the movement of the motors of each joint of the robotic arm is controlled accordingly.

[0072] Specifically, in this embodiment, the following coordinate systems are defined: {Base} is the fixed coordinate system of the robot arm base; {Tool} is the coordinate system of the tool center point of the adaptive gripper 4 at the end of the robot arm; {Car_Taught} is the coordinate system of the vehicle body target during teaching; and {Car_Actual} is the coordinate system of the current vehicle body target detected in real time by the visual positioning unit.

[0073] The teaching path is essentially a sequence of poses (positions and attitudes) of {Tool} in the {Base} coordinate system. The predictive control unit first calculates the deviation transformation matrix T_offset = T({Car_Actual}) * T({Car_Taught}) between the teaching path and the current actual vehicle target. -1 Simultaneously, based on the difference between the real-time grasping posture and the "standard grasping posture baseline," the posture compensation matrix T_compensate is calculated. For each pose point P_taught in the teaching path, the controller calculates a new target pose point P_actual = T_offset * P_taught * T_compensate. By performing this calculation on all points on the path, a customized autonomous running trajectory that is fully adapted to the current vehicle position and grasping posture can be generated. Subsequently, the controller converts each target pose point on the trajectory into the target angle required by each joint through inverse kinematics calculation and sends commands to drive the joint motors to move.

[0074] The main controller 108 also integrates a force control coordination unit: this unit mainly consists of monitoring logic located on the second arm assembly 3, connected to the sub-controller 302 and the main controller 108. In autonomous operation mode, this monitoring logic continuously monitors the readings of the sub-controller 302. Under normal circumstances, the readings are close to zero. When the operator applies external force to the force sensor located at the end of the handle 304, the readings change. Once the torque exceeds a preset safety threshold, the monitoring logic immediately triggers an interrupt, sending a pause command to the predictive control unit.

[0075] Specifically, during autonomous operation, the monitoring logic within the secondary controller 302 continuously compares the real-time readings of the force sensor with the threshold vector. Once the reading exceeds the threshold, the primary controller 108 immediately executes the highest-priority pause command, stopping trajectory execution and simultaneously switching the control mode of all joints from "position control mode" to "zero-torque compliant drag mode." In this mode, the motors only output torque to counteract gravity, allowing the operator to manually adjust the position of the robotic arm as easily as moving a weightless object.

[0076] When an assembly path needs to be entered for a new vehicle model or a new workstation, the operator first manually drags the robotic arm with the door 5 to the starting position of the assembly. At this moment, the operator confirms the start of teaching via control button 303. At this time, the path learning unit not only begins to prepare to record the robotic arm's motion data, but also simultaneously collects and stores the current extension / retraction position data of all telescopic support probes 4052 in the adaptive contour support module 405. This set of data is defined as the "standard gripping posture reference" for this teaching path.

[0077] Specifically, the determination process of this reference is as follows: Several telescopic support probes 4052 abut against the car door 5, so that some of the telescopic support probes 4052 are in their original extended state without contacting the car door 5, while the other part of the telescopic support probes 4052 are abutted by the car door 5, achieving different degrees of retraction. The main controller 108 uses the extended positions of the telescopic support probes 4052 in their original state as data base points, and compares them with the real-time retraction data of the other part of the telescopic support probes 4052 that are retracted due to being abutted by the car door 5, so as to accurately calculate and determine the relative positional relationship between the adaptive gripper 4 and the car door 5, forming the "standard gripping posture reference". Then, the operator drags the robot arm to smoothly install the car door 5 onto the car body. During this process, the path learning unit records the motion data such as the angle and displacement of each joint at a high frequency, forming a complete standard teaching path containing posture information, and stores it together with the "standard gripping posture reference".

[0078] During normal production, the system operates in autonomous mode. The activation, data acquisition, and execution process for this mode are as follows:

[0079] The system switches between "teach mode" and "autonomous operation mode" via the user interface or a specific control button 303. In autonomous operation mode, the entire work cycle is triggered by a "vehicle in place" signal from the production line PLC (Programmable Logic Controller). This signal indicates that a new car has entered the assembly station and notifies the main controller 108 to begin autonomously moving to the storage location at door 5.

[0080] After the operator control device completes the grasping of door 5, the predictive control unit reads the real-time attitude data of the current adaptive contour support module 405 and compares it with the stored "standard grasping attitude reference" to calculate the deviation between the two (i.e., the attitude compensation matrix). When executing subsequent autonomous paths, the system will add this deviation to the teaching path in real time for correction, ensuring that even if there are slight differences in each grasping, the final installation position of door 5 can remain highly consistent.

[0081] On the other hand, when grasping the car door 5, the main controller 108 can control the adaptive contour support module 405 to restore the real-time posture data of the "standard grasping posture reference". The operator can use the extended positions of several telescopic support probes 4052 in their original state as data reference points to directly fit with the outer wall of the end of the car door 5 near the door limiter, realizing rapid positioning between the adaptive contour support module 405 and the car door 5. After receiving the PLC signal, the main controller 108 immediately activates the vision positioning unit. The 3D industrial camera acquires images of the vehicle side, identifies and calculates the three-dimensional coordinates of key feature points such as the hinge holes of the vehicle body, forming a target coordinate system, that is, the predetermined position of the vehicle.

[0082] The predictive control unit retrieves a pre-stored standard teaching path matching the current vehicle model from memory. Simultaneously, it queries the extension and retraction data of each telescopic support probe 4052 in the adaptive contour support module 405 of the adaptive fixture 4. This data is used to confirm the model of the door 5 and its actual gripping posture in the fixture, forming a posture compensation matrix.

[0083] The predictive control unit executes the core coordinate transformation algorithm, which calculates and generates in real time an autonomous running trajectory in absolute coordinates, customized for this operation, based on the target coordinate system provided by visual positioning and the attitude compensation matrix provided by the fixture, relative to the teaching path.

[0084] The main controller 108 controls the drive robot to move autonomously along the generated final path, transporting the door 5 to the vehicle body. Throughout the movement, the force control coordination unit continuously monitors any applied external force at a high frequency through a force sensor located at the end of the handle 304.

[0085] If the operator detects any abnormalities during autonomous execution (such as minor deviations in the posture of door 5, potential collision risks, etc.), or if fine-tuning is required, they can simply press the force sensor located at the end of handle 304. Once the secondary controller 302 detects that the external force exceeds the preset safety threshold, the force control coordination unit will immediately issue a highest-priority pause command to the main controller 108. The main controller 108 will instantly stop the execution of the autonomous path and put the robotic arm into a zero-torque compliant dragging mode, seamlessly returning control to the operator. After the operator completes the adjustments, they can choose to continue autonomous operation or manually complete the remaining operations via control button 303.

[0086] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0087] Although embodiments of the 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 invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A robotic arm for assembling automobile doors, characterized in that: The door assembly robot includes: a fixed base (1), a first arm assembly (2) is driven connected to the top of the fixed base (1), and a second arm assembly (3) is driven connected to the bottom of the first arm assembly (2) away from the fixed base (1). An adaptive gripper (4) is installed at the end of the robotic arm for gripping a car door (5). It also includes a visual positioning unit for identifying the predetermined position of vehicles on the assembly line; The fixed base (1) includes a support base (101), a rotating platform (102) is fixedly mounted on the top of the support base (101), a support rod (104) is rotatably connected to the top of the rotating platform (102), a first angle detection disk (103) is fixedly mounted on the top outer wall of the rotating platform (102), a fixed platform (105) is fixedly mounted on the bottom outer wall of the support rod (104), a linear driver (106) is rotatably connected to the top of the fixed platform (105), a first angle sensor (107) is fixedly mounted on the outer wall of the fixed platform (105) away from the linear driver (106), and a main controller is fixedly mounted on the outer wall of the support rod (104). 108), both sides of the top of the support rod (104) are fixedly equipped with support frames (109), and the top of the two sets of support frames (109) are fixedly equipped with top plates (110). The inner walls of the two sets of support frames (109) are respectively rotatably connected with a first connecting rod (111) and a second connecting rod (112). The end of the second connecting rod (112) near the linear actuator (106) is rotatably connected to the top telescopic end of the linear actuator (106). The outer walls of the first connecting rod (111) and the second connecting rod (112) away from the linear actuator (106) are provided with crossbars (113), and the outer walls of the first connecting rod (111) and the second connecting rod (112) are respectively rotatably connected to the ends of the crossbars (113). The bottom cavity of the support rod (104) is inlaid with a servo motor, and the support rod (104) is fixedly assembled with the rotating platform (102) through the output end of the servo motor. The main controller (108) is electrically connected to the servo motor, the linear driver (106), and the first angle sensor (107) respectively. The measuring end of the first angle sensor (107) corresponds to the outer wall of the first angle detection disk (103). The first arm assembly (2) includes a second arm housing (201), a first rotary drive (202) is fixedly mounted on the top inner wall of the second arm housing (201), a second position angle sensor (203) is fixedly mounted on the outer wall of the second arm housing (201), a connecting shaft (204) is fixedly mounted on the top output end of the first rotary drive (202), a second angle detection disk (205) is fixedly mounted on the bottom outer wall of the connecting shaft (204), and a second arm rod (206) is fixedly mounted on the top of the connecting shaft (204). The second arm (206) has a second rotary drive (207) embedded in the inner cavity of the end away from the second arm housing (201). The second arm (206) has a third position angle sensor (208) fixedly mounted on the outer wall of the end away from the second arm housing (201). The measuring end of the second position angle sensor (203) corresponds to the outer wall of the second angle detection disk (205). The inner wall of the second arm housing (201) is rotatably connected to the ends of the first connecting rod (111) and the second connecting rod (112). The second arm assembly (3) includes a third arm (301), a secondary controller (302) is fixedly mounted on the outer wall of the third arm (301), control buttons (303) are fixedly mounted on both sides of the bottom of the third arm (301), a handle (304) is fixedly mounted on the bottom outer wall of the third arm (301), and a third angle detection disc (305) is fixedly mounted on the top of the third arm (301). The outer wall of the third angle detection disk (305) corresponds to the measuring end of the third position angle sensor (208). The top of the third arm (301) and the output end of the second rotation drive (207) are fixedly assembled. The sub-controller (302) and the control button (303) are electrically connected to the main controller (108). The adaptive clamp (4) includes a clamp frame (401), a mounting base (402) is fixedly mounted on the inner wall of the clamp frame (401), at least one set of suction cup assemblies (403) is fixedly mounted on the end of the mounting base (402), a connecting frame (404) is fixedly mounted on the inner wall of the suction cup assembly (403), an adaptive contour support module (405) is fixedly mounted on the bottom of the connecting frame (404), a suction cup frame (406) is fixedly mounted on the top of the connecting frame (404), and suction cup bodies (407) are fixedly mounted on both ends of the suction cup frame (406). The gas connection end of the suction cup body (407) is connected to the negative pressure device through a hose, and the hose is fixed to the outer wall of the fixed base (1), the first arm assembly (2), and the second arm assembly (3). The adaptive contour support module (405) and the negative pressure device are both electrically connected to the main controller (108) and controlled by the control button (303). The adaptive contour support module (405) includes a support base (4051), and a plurality of telescopic support probes (4052) are fixedly assembled on the outer wall of the support base (4051). Several of the telescopic support probes (4052) are electrically connected to the main controller (108); The main controller (108) also includes: The path learning unit is used to respond to the movement of the robot hand under manual dragging and to record the motion data of each joint of the robot hand to form a teaching path; A predictive control unit, connected to the visual positioning unit and the path learning unit, is used to predict and autonomously control the robotic arm to perform the door assembly action by combining the predetermined position of the vehicle with the taught path; and The force control coordination unit is used to monitor the external force applied to the robot arm during the autonomous assembly process, and to suspend the autonomous execution of the robot arm when the external force exceeds a preset threshold. A force sensor is provided at the end of the handle (304) to detect the external force applied by the operator when the robot arm is running automatically and needs to be manually stopped in an emergency.

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