Mechanical arm gripper and automobile door frame gripping method

Abstract

The invention discloses a mechanical arm gripper and an automobile door frame grabbing method.The mechanical arm gripper comprises a frame piece and a driving piece, the driving piece is connected with a positioning unit, the driving piece is used for driving the positioning unit to move in the X direction or move on the X-Y plane, the driving piece is further connected with a plurality of clamping units capable of moving in the X direction, and in the first state, the clamping units are clamped in the X direction; in the first state, the materials are at least partially located in the space under the frame piece, the materials are integrally suspended, and in the second state, the materials are disengaged from the clamping jaw and located at the station. Through cooperation of the driving part, the positioning unit and the clamping unit, the automobile door frame can be conveyed in the mode that the automobile door frame is positioned firstly and then clamped, the positioning unit moves in the X direction or in the X-Y plane, and the clamping unit moves in the X direction, so that the automobile door frame conveying device can adapt to automobile door frames of different sizes and shapes; and compared with the mode that different types of mechanical arm grippers are replaced, the operation space is saved, and the production and manufacturing cost can also be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile door frame production, and particularly relates to a robotic arm gripper and a method for gripping an automobile door frame. Background Art

[0002] With the continuous changes in the automobile market and the diversification of user needs, small-batch and multi-variety production has become one of the main trends in modern automobile manufacturing. To meet this demand, the production line must have a high degree of flexibility to adapt to the rapid switching and production of multiple vehicle models. For example, in the automobile door production line, robots are used to perform tasks such as gripping and transporting doors. The traditional flexibility of door production, that is, during the automobile manufacturing process, the ability of the door production line to flexibly adjust and adapt according to different vehicle models and consumer demands. This flexible production method can effectively respond to changes in market demand and requirements for personalized customization, thereby improving production efficiency and reducing production costs.

[0003] In the flexible production method, different gripper toolings are replaced by robots to grip doors of different vehicle models. However, as the number of vehicle models increases, especially when there are more than four different vehicle models, the drawbacks of this method gradually become prominent. It is difficult to have enough space around the robot to place various types of grippers. Moreover, when each vehicle model is equipped with a dedicated gripper, it will lead to high hardware manufacturing costs. In addition, when switching vehicle models, replacing the matching gripper will also result in wasted production time due to waiting. Summary of the Invention

[0004] The present invention provides a robotic arm gripper and a method for gripping an automobile door frame, which can solve the problems raised in the background art.

[0005] A robotic arm gripper includes: a frame member;

[0006] The frame member is connected to a driving member, the driving member is connected to a positioning unit, the driving member is used to drive the positioning unit to move in the X direction or move in the X-Y plane, and the positioning unit can move according to the size and shape of the material to position the material;

[0007] The driving member is further connected to a plurality of clamping units that can move in the X direction. Each clamping unit includes a jaw that can move up and down in the Z direction. The clamping unit grips the material at the edge of the material in a pneumatic opening and closing manner;

[0008] The positioning unit cooperates with the clamping unit to make the clamped material present at least two states;

[0009] In the first state, at least a part of the material is located in the space directly below the frame member, and the whole material is in a suspended state;

[0010] In the second state, the material is separated from the jaw, and the material is located at the work station.

[0011] Preferably, the driving member includes a first linear motor module, and the first linear motor module includes four movers that can slide along the X direction at the bottom of the frame member.

[0012] Preferably, the four movers are coaxially arranged. The four movers are, in sequence along the X direction, a first mover, a second mover, a third mover, and a fourth mover. The third mover is connected to a linear ball guide type slide table, and both the first mover and the fourth mover are connected with the clamping units.

[0013] Preferably, the positioning unit includes a first telescopic pin cylinder positioning unit and a second telescopic pin cylinder positioning unit. The first telescopic pin cylinder positioning unit is fixed to the second mover, and the second telescopic pin cylinder positioning unit is slidably connected to the linear ball guide type slide table.

[0014] Preferably, the driving member further includes a second linear motor module. The second linear motor module includes two movers that can slide along the X direction at the bottom of the frame member, namely a fifth mover and a sixth mover. Both the fifth mover and the sixth mover are connected with the clamping units.

[0015] Preferably, the first telescopic pin cylinder positioning unit and the second telescopic pin cylinder positioning unit have the same structure. The second telescopic pin cylinder positioning unit includes a positioning pin that can move along the Z direction.

[0016] Preferably, four clamping units are provided, and the four clamping units have the same structure. The four clamping units are respectively a first clamping unit, a second clamping unit, a third clamping unit, and a fourth clamping unit.

[0017] Preferably, the driving member further includes a driver, and the driver is electrically connected to the first linear motor module and the second linear motor module.

[0018] Preferably, a connecting member is provided at the top of the frame member, and the connecting member is connected to a robot six-axis quick-change device.

[0019] An automobile door frame grasping method uses a robotic arm gripper. The automobile door frame grasping method includes:

[0020] S1. Each component of the robotic arm gripper performs self-inspection, and the jaws are located at the initial position;

[0021] S2. The driving member drives the positioning unit to move on the X-Y plane, and the positioning unit positions the automobile door frame according to the size and shape of the automobile door frame;

[0022] After the positioning unit completes the positioning, the driving member drives the clamping unit to move in the X direction until the clamping unit moves to the contour edge of the vehicle door frame. Then the gripper moves downward to grasp the vehicle door frame and then moves upward, so that the vehicle door frame presents the first state;

[0023] S4. The robot manipulator drives the manipulator gripper and the grasped vehicle door frame to move until the vehicle door frame is directly above the working station. Then the manipulator drives the entire manipulator gripper to move downward until the vehicle door frame contacts the working station, and the gripper disengages from the vehicle door frame, so that the vehicle door frame presents the second state;

[0024] S5. The positioning unit and the clamping unit return to their original positions, return to S1, and repeat S1 - S5 until all vehicle door frames are transported to the corresponding working stations.

[0025] Advantages of the present invention:

[0026] (1) In the present invention, through the cooperation between the driving member, the positioning unit and the clamping unit, the vehicle door frame can be transported in a way that it is first positioned and then clamped. The ways of the positioning unit moving in the X direction or moving in the X - Y plane, and the clamping unit moving in the X direction can adapt to vehicle door frames of different sizes and shapes. Compared with replacing different types of manipulator grippers, it not only saves the operation space but also reduces the production and manufacturing costs.

[0027] (2) In the present invention, when applied to the production line, there is no need to replace the manipulator grippers adapted to different vehicle door frames, avoiding the generation of waiting time and effectively improving the production efficiency. Description of the Drawings

[0028] Figure 1 is a schematic structural diagram of a manipulator gripper of the present invention;

[0029] Figure 2 is a top view of a manipulator gripper of the present invention;

[0030] Figure 3 is Figure 1 a bottom view of the middle frame member, the first linear motor module and the second linear motor module in

[0031] Figure 4 is Figure 1 a schematic structural diagram of the second telescopic pin cylinder positioning unit in

[0032] Figure 5 is Figure 1 a schematic structural diagram of the first clamping unit in

[0033] Figure 6 is a schematic flow diagram of a method for grasping a vehicle door frame of the present invention.

[0034] Description of the reference numerals:

[0035] 1. Frame member; 2. Driver; 3. Robot six-axis quick-change device; 4. Connecting member; 5. Cylinder control system; 6. First linear motor module; 61. First mover; 62. Second mover; 63. Third mover; 64. Fourth mover; 7. Second linear motor module; 71. Fifth mover; 72. Sixth mover; 8. Linear ball guide type slide; 9. First telescopic pin cylinder positioning unit; 10. Second telescopic pin cylinder positioning unit; 101. Fixed block; 102. Cylinder; 103. Connecting block; 104. Positioning pin; 11. First clamping unit; 111. Reinforcing block; 112. Electric cylinder; 113. Right-angle block; 114. Pneumatic gripper; 12. Second clamping unit; 13. Third clamping unit; 14. Fourth clamping unit. Detailed implementation manners

[0036] The following will describe in detail the specific implementation manners of the present invention, but it should be understood that the protection scope of the present invention is not limited by the specific implementation manners.

[0037] As Figure 1 - Figure 2 shown, a robotic arm gripper is applicable to the robotic arm of a robot. The robotic arm gripper includes: a frame member 1, and a track for the movement of several movers is provided at the bottom of the frame member 1. A connecting member 4 is provided at the top of the frame member 1, and the connecting member 4 is connected to the robot six-axis quick-change device 3, and the robot six-axis quick-change device 3 is installed at the end of the robot robotic arm. The robot six-axis quick-change device 3 is an automated device for a robot system that can quickly replace or change the end effector (such as a gripper, a tool) of the robot. The robot six-axis quick-change device 3 is commonly used in the fields of industrial automation, assembly, welding, and material handling. Its core purpose is to improve production efficiency, reduce manual intervention, and achieve flexible switching of the robot's work tasks.

[0038] The frame member 1 is connected with a driving member, and the driving member includes a driver 2, a first linear motor module 6 and a second linear motor module 7. The driver 2 is fixedly installed at the top of the frame member 1, and the driver 2 is electrically connected to the first linear motor module 6 and the second linear motor module 7.

[0039] Specifically, as Figure 3 shown, the first linear motor module 6 includes four movers that can slide along the X direction at the bottom of the frame member 1. The four movers are coaxially arranged, and the four movers are successively the first mover 61, the second mover 62, the third mover 63, and the fourth mover 64 along the X direction. The third mover 63 is connected to the linear ball guide type slide 8. The second linear motor module 7 includes two movers that can slide along the X direction at the bottom of the frame member 1, namely the fifth mover 71 and the sixth mover 72.

[0040] As Figure 1As shown in the figure, a driving member is connected to a positioning unit. The driving member is used to drive the positioning unit to move in the X direction or in the X-Y plane. The positioning unit can move according to the size and shape of the material to position the material.

[0041] Among them, the positioning unit includes a first telescopic pin cylinder positioning unit 9 and a second telescopic pin cylinder positioning unit 10. The first telescopic pin cylinder positioning unit 9 is fixed to the second mover 62, and the second telescopic pin cylinder positioning unit 10 is slidably connected to the linear ball guide type slide 8.

[0042] As Figure 1 、 Figure 4 shown in the figure, the first telescopic pin cylinder positioning unit 9 and the second telescopic pin cylinder positioning unit 10 have the same structure. The second telescopic pin cylinder positioning unit 10 includes a fixed block 101, and the fixed block 101 is slidably connected to the linear ball guide type slide 8. A cylinder 102 is fixedly installed on the fixed block 101, and the output end of the cylinder 102 is connected to a connecting block 103. The connecting block 103 is L-shaped. A positioning pin 104 is fixedly installed at the bottom of the connecting block 103. The positioning pin 104 can move along the Z direction under the drive of the cylinder 102 until the positioning pin 104 is inserted into the positioning hole on the automobile door frame.

[0043] It can be understood that the fixed block 101 in the second telescopic pin cylinder positioning unit 10 can move along the Y direction on the linear ball guide type slide 8. With the drive of the third mover 63, the fixed block 101 can move in the X-Y plane. The fixed block 101 in the first telescopic pin cylinder positioning unit 9 is fixed to the second mover 62. Under the drive of the second mover 62, the fixed block 101 only moves along the X direction. This also enables the positioning unit to only need to first position one of the positioning holes on the automobile door frame through the positioning pin 104 in the first telescopic pin cylinder positioning unit 9 when positioning the positioning holes on automobile door frames of different sizes, and then move the fixed block 101 in the second telescopic pin cylinder positioning unit 10 according to the size and specifications of the automobile door frame, so that the positioning pin 104 in the second telescopic pin cylinder positioning unit 10 positions another positioning hole on the automobile door frame. This positioning method does not require adjusting the two positioning pins 104 in the X-Y plane, further improving the positioning efficiency of the positioning unit.

[0044] As Figure 1 、 Figure 5 shown in the figure, the driving member is also connected with a plurality of clamping units that can move in the X direction. Four clamping units are provided, and the four clamping units have the same structure. The four clamping units are respectively fixed to the first mover 61, the fourth mover 64, the fifth mover 71, and the sixth mover 72. The four clamping units can be arbitrarily combined with the first mover 61, the fourth mover 64, the fifth mover 71, and the sixth mover 72. The four clamping units are respectively the first clamping unit 11, the second clamping unit 12, the third clamping unit 13, and the fourth clamping unit 14.

[0045] Specifically, the first clamping unit 11 includes a reinforcement block 111 which is fixedly installed on the fourth mover 64 (or the first mover 61, the fifth mover 71, the sixth mover 72). The reinforcement block 111 is fixedly installed with an electric cylinder 112. The output end of the electric cylinder 112 is fixedly installed with a right-angle block 113, and the right-angle block 113 is fixedly installed with a clamping jaw. Driven by the electric cylinder 112, the right-angle block 113 and the clamping jaw can move up and down in the Z direction. In this embodiment, the clamping jaw adopts a pneumatic clamping jaw 114, so that the first clamping unit 11 can clamp the material at the edge of the material in a pneumatic opening and closing manner.

[0046] The inventor found that the octagonal tube fixed car door handle in the prior art, although having a stable structure, has poor adaptability and is difficult to grasp the car doors of different models. The suction cup type car door handle has better adaptability but is applicable to smooth surfaces and is dangerous. The three-point card slot type car door handle has good adaptability but requires high positioning accuracy, and it also grabs the car door while positioning, which is easy to damage the positioning holes of the car door frame.

[0047] In this application, the pneumatic clamping jaw 114 cooperates with the positioning unit to grasp the car door frames of different models, and the pneumatic clamping jaw 114 grasps in a clamping manner, which conforms to more application scenarios and is not limited by the smoothness of the surface of the car door frame. When the first telescopic pin cylinder positioning unit 9 and the second telescopic pin cylinder positioning unit 10 are positioning, no external force is applied to the positioning holes on the car door frame, so that the positioning holes of the car door frame can maintain relatively good quality before and after the car door frame is grasped.

[0048] In the present invention, the positioning unit cooperates with the clamping unit to make the clamped material present at least two states.

[0049] In the first state, the material (i.e., the car door frame) is at least partially located in the space directly below the frame member 1, and the whole material is in a suspended state. At this time, the positioning pins 104 in the first telescopic pin cylinder positioning unit 9 and the positioning pins 104 in the second telescopic pin cylinder positioning unit 10 are inserted into the positioning holes in the car door frame, and the pneumatic clamping jaws 114 of the clamping unit clamp the edge of the car door frame. The cylinder 102 and the electric cylinder 112 are driven synchronously, and the positioning pins 104 and the pneumatic clamping jaws 114 move up and down synchronously, so that the car door frame moves up and down with the pneumatic clamping jaws 114.

[0050] In the second state, the car door frame disengages from the clamping jaws, and the material is at the working station. At this time, the positioning pins 104 in the first telescopic pin cylinder positioning unit 9 and the positioning pins 104 in the second telescopic pin cylinder positioning unit 10 disengage from the positioning holes in the car door frame, and the pneumatic clamping jaws 114 of the clamping unit loosen the car door frame.

[0051] In this embodiment, the frame member 1 is further provided with a cylinder control system 5, which can control the opening and closing of the cylinder 102. Other movers and electric cylinders 112 can be controlled for movement through an external controller. In some embodiments, the frame member 1 is also connected to a control system, and the control system can adopt a PLC controller to control the opening and closing of the cylinder 102 and the electric cylinder 112, and can also control the movement of the mover in the X direction and the moving distance of the fixing block 101 on the linear ball guide type slide 8.

[0052] As Figure 6 shown, in one embodiment, the present invention provides a method for grasping an automobile door frame, using a robotic arm gripper. The method for grasping an automobile door frame includes:

[0053] S1. Each component of the robotic arm gripper performs self-inspection, and the gripper is located at the initial position.

[0054] The initial position of the pneumatic gripper 114 is at the outermost end of the bottom track of the frame member 1, and the pneumatic gripper 114 is in an open state, facilitating subsequent grasping of the automobile door frame, and the robotic arm is also in a horizontal alignment state. This design ensures that when the robotic system starts, the pneumatic gripper 114 will not accidentally contact the automobile door frame, and at the same time provides the maximum movement range for the pneumatic gripper 114. During the preparation stage, the robotic system will control each component of the robotic arm gripper to perform self-inspection, including checking the movement range of the pneumatic gripper 114 and the pressure of the cylinder 102 to ensure that all components are in good working condition.

[0055] S2. The driving member drives the positioning unit to move on the X-Y plane, and the positioning unit positions the automobile door frame according to the size and shape of the automobile door frame.

[0056] The automobile door frame is conveyed to the robot. The robotic arm gripper is positioned through the positioning pins 104 on the first telescopic pin cylinder positioning unit 9 and the second telescopic pin cylinder positioning unit 10. The pneumatic positioning device 9 can move in the X direction under the drive of the second mover 62, and the second telescopic pin cylinder positioning unit 10 can move on the X-Y plane through the third mover 63 and the linear ball guide type slide 8. This design enables the two positioning pins 104 to be adjusted according to the size and shape of the automobile door frame to ensure accurate positioning.

[0057] When the two positioning pins 104 move to the positioning holes on the automobile door frame in the X direction or on the X-Y plane, the cylinder 102 drives the positioning pins 104 to move downward until the positioning pins 104 are stuck into the positioning holes of the automobile door frame, and at this time, the positioning is completed.

[0058] S3. After the positioning unit completes the positioning, the driving member drives the clamping unit to move in the X direction until the clamping unit moves to the contour edge of the automobile door frame. The gripper moves downward to grasp the automobile door frame and then moves upward, making the automobile door frame present the first state.

[0059] Driven by the first mover 61, the fourth mover 64, the fifth mover 71 and the sixth mover 72, the four clamping units move along the X direction to adapt to the grasping of car door frames of different shapes and specifications. This design enables the pneumatic gripper 114 to flexibly adapt to car door frames of different sizes and shapes while maintaining a stable grasping force.

[0060] In the startup phase, the control system automatically adjusts the position and force of the pneumatic gripper 114 according to the size and shape of the car door frame to ensure the stability and safety of grasping. Driven by the electric cylinder 112, the pneumatic gripper 114 can move in the Z direction and clamp and release the car door frame in a pneumatic opening and closing manner.

[0061] After the pneumatic gripper 114 successfully grasps the car door frame, it moves upward under the action of the electric cylinder 112. At the same time, the cylinder 102 also drives the positioning pin 104 to move upward. At this time, the car door frame is in the first state, at least part of the car door frame is located in the space directly below the frame member 1, and the whole car door frame is in a suspended state.

[0062] Stress sensors are equipped on the pneumatic grippers 114 of the four clamping units to sense the force during grasping. By monitoring the grasping force, it can be judged whether the car door frame is successfully grasped. If the grasping force exceeds the set threshold, the grasping strategy needs to be readjusted. This design can ensure that the pneumatic gripper 114 can be monitored and the grasping force adjusted in real time during the grasping process to avoid damaging the car door frame. When dealing with abnormal situations where the grasping force exceeds the threshold, the control system will adjust the grasping strategy according to the feedback information of the stress sensor, such as adjusting the position and force of the pneumatic gripper 114, or pausing the operation and issuing an alarm, waiting for manual intervention.

[0063] S4. The robot manipulator drives the manipulator gripper and the grasped car door frame to move until the car door frame is directly above the work station. Then the manipulator drives the entire manipulator gripper to move downward until the car door frame contacts the work station, and the gripper disengages from the car door frame, causing the car door frame to assume the second state.

[0064] After the car door frame moves upward, the robot manipulator drives the manipulator gripper and the grasped car door frame to move. At this time, the positioning unit, the clamping unit and the frame member 1 remain relatively stationary until the car door frame contacts the work station. Then the pneumatic gripper 114 releases and disengages from the car door frame. During the process of releasing the car door frame, the control system will ensure that the car door frame is placed smoothly on the work station to avoid damage. At this time, the car door frame is in the second state, that is, the car door frame disengages from the pneumatic gripper 114 and the car door frame is located at the work station.

[0065] S5. The positioning unit and the clamping unit are reset, return to S1, and repeat S1 - S5 until all automobile door frames are transported to the corresponding workstations.

[0066] It can be understood that after the pneumatic gripper 114 releases the automobile door frame, the mover connecting the clamping unit will move to the extreme end of the bottom slide rail of the frame member 1 and return to the initial state. This design enables the robotic arm gripper to quickly return to the initial state after completing the loading and unloading tasks of the automobile door frame, preparing for the next transportation operation.

[0067] In this application, through the cooperation between the driving member, the positioning unit and the clamping unit, the automobile door frame can be transported in a manner of being positioned first and then clamped, and it can also adapt to automobile door frames of different sizes and shapes. Compared with replacing different types of robotic arm grippers, it not only saves operation space but also reduces production and manufacturing costs. When applied to the production line, there is no need to replace the robotic arm grippers adapted to different automobile door frames, avoiding waiting time and effectively improving production efficiency.

[0068] The above-disclosed are only several specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A robotic arm gripper, characterized in that: include: Frame member (1); The frame member (1) is connected to a driving member, the driving member is connected to a positioning unit, the driving member is used to drive the positioning unit to move in the X direction or on the XY plane, and the positioning unit can move according to the size and shape of the material to position the material; The driving member is also connected to a plurality of clamping units that can move in the X direction, and the clamping units include clamping jaws that can be raised and lowered in the Z direction, and the clamping units are pneumatically opened and closed so that the clamping jaws clamp the material at the edge of the material; The positioning unit cooperates with the clamping unit to make the clamped material present at least two states; In the first state, at least part of the material is located in the space directly below the frame member (1), and the material as a whole is suspended in the air; In the second state, the material is out of the clamping jaws and is located at the work station.

2. A robotic arm gripper as claimed in claim 1, characterized in that: The driving member comprises a first linear motor module (6), and the first linear motor module (6) comprises four movers which can slide along the X direction at the bottom of the frame member (1).

3. A mechanical arm gripper as claimed in claim 2, characterized in that: The four movers are coaxially arranged, and the four movers are respectively a first mover (61), a second mover (62), a third mover (63), and a fourth mover (64) along the X direction; the third mover (63) is connected to a linear ball guide type slide (8); and the first mover (61) and the fourth mover (64) are both connected to the clamping unit.

4. A mechanical arm gripper as claimed in claim 3, characterized in that: The positioning unit comprises a first telescopic pin cylinder positioning unit (9) and a second telescopic pin cylinder positioning unit (10), wherein the first telescopic pin cylinder positioning unit (9) is fixed to the second mover (62), and the second telescopic pin cylinder positioning unit (10) is slidably connected to the linear ball guide type slide (8).

5. A mechanical arm gripper as claimed in claim 2, characterized in that: The driving member further comprises a second linear motor module (7), the second linear motor module (7) comprising two movers which can slide along the X direction at the bottom of the frame member (1), namely a fifth mover (71) and a sixth mover (72), the fifth mover (71) and the sixth mover (72) being both connected to the clamping unit.

6. A mechanical arm gripper according to claim 1, characterized in that: The first telescopic pin cylinder positioning unit (9) and the second telescopic pin cylinder positioning unit (10) have the same structure, and the second telescopic pin cylinder positioning unit (10) comprises a positioning pin (104) movable along the Z direction.

7. A robotic arm gripper according to claim 1, characterized in that: Four clamping units are provided, and the four clamping units have the same structure. The four clamping units are respectively a first clamping unit (11), a second clamping unit (12), a third clamping unit (13), and a fourth clamping unit (14).

8. A robotic arm gripper as claimed in claim 5, characterized in that: The driving component further comprises a driver (2), and the driver (2) is electrically connected to the first linear motor module (6) and the second linear motor module (7).

9. A mechanical arm gripper according to claim 1, characterized in that: A connecting piece (4) is arranged on the top of the frame member (1), and the connecting piece (4) is connected to the robot six-axis quick-change device (3).

10. A method for grasping a car door frame, using a mechanical arm gripper as claimed in any one of claims 1 to 9, characterized in that: include: S1, each component of the robot gripper is self-checked, and the gripper is in the initial position; S2, the driving member drives the positioning unit to move on the XY plane, and the positioning unit positions the automobile door frame according to the size and shape of the automobile door frame; S3, after the positioning unit completes the positioning, the driving member drives the clamping unit to move in the X direction until the clamping unit moves to the edge of the contour of the automobile door frame, and the clamping claw moves down to grab the automobile door frame and then moves up, so that the automobile door frame presents the first state; S4, the robot arm drives the robot arm gripper and the car door frame it grasps to move until the car door frame is directly above the workstation, and the robot arm then drives the entire robot arm gripper to move downward until the car door frame contacts the workstation and the gripper is separated from the car door frame, so that the car door frame is in the second state; S5, the positioning unit and the clamping unit are reset, and the process returns to S1, and S1 to S5 are repeated until all the automobile door frames are transported to the corresponding workstations.

Images