A Safety Protection and Control Method for a Production Line Including a Seventh-Axis Robot

Abstract

This invention provides a safety protection control method for a production line including a seventh-axis robot. It includes the following steps: detecting obstacles in the aisle using lidar; classifying protective doors into safety doors and maintenance doors, with door opening and closing information transmitted to the PLC control system via the electric lock signal of the protective door, and performing classified control of the trigger signal together with the radar trigger signal; adding robot interruption handling functions, including: stop operation interruption and deceleration operation interruption; and designing a safety protection control and production line operation interruption recovery method based on multiple lidars and multiple protective doors. This invention integrates the characteristics of lidar and protective doors, combining active and passive protection through reasonable combination, fully ensuring the safe operation of the production line while increasing the online maintenance capability of the production line, making the user interaction more user-friendly, and improving the safety and efficiency of the production line operation.

Description

Technical Field

[0001] This invention belongs to the field of automated production lines containing a seventh-axis robot, and provides a safety protection and control method for a production line containing a seventh-axis robot. Background Technology

[0002] Robots with a seventh axis typically consist of a six-axis robot and a robot track, usually categorized into floor-mounted and overhead tracks. In a production line with a seventh-axis robot, the production equipment is arranged linearly in parallel along the robot's floor track. Driven by the seventh axis, the robot can move freely between various production equipment units, performing operations such as loading and unloading materials, ultimately enabling the flow of workpieces, tools, and fixtures across the production line.

[0003] Since a production line contains multiple pieces of equipment, these devices have a certain probability of failure during operation. This may necessitate timely troubleshooting and repair by maintenance personnel. When maintenance personnel enter the production line through safety doors, careful consideration and unified design are needed regarding how to control and restore the production line's operation, and how to balance the safety of maintenance personnel with ensuring the production line's operational efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a safety protection and control method for a production line containing a seventh-axis robot, so as to overcome the above-mentioned defects.

[0005] The technical solution adopted by the present invention to achieve the above objectives is as follows:

[0006] A production line safety protection and control system incorporating a seventh-axis robot includes: a safety fence, a robot, a ground track, an aisle, multiple production devices, multiple protective doors, and multiple lidar sensors, wherein:

[0007] The ground track, passageway, and multiple production devices are all located within a safety fence. The robot moves on the ground track, the passageway is located between the ground track and the production devices, the safety fence is equipped with multiple protective doors, and lidar is installed on the robot and between the production devices and the passageway.

[0008] The protective door is divided into a safety door and a maintenance door. The safety door is located on one side of the ground track and at least one end of the passageway, while the maintenance door is located on one side of the production equipment.

[0009] A safety protection and control method for a production line including a seventh-axis robot includes the following steps:

[0010] A lidar is installed on the robot as an airborne lidar, so that it moves with the robot and can detect whether there are obstacles in the passageway in real time.

[0011] Multiple lidars are installed between the production equipment and the passageway as equipment lidars, and each lidar detects in real time whether there are obstacles in the passageway in front of the corresponding production equipment.

[0012] Connect the safety door opening signal, maintenance door opening signal, equipment radar trigger signal, and airborne radar trigger signal to the PLC control system respectively. Set the safety door opening signal and airborne radar trigger signal as stop operation interruption trigger sources, and set the maintenance door opening signal and equipment radar trigger signal as speed reduction operation interruption trigger sources.

[0013] Construct robot stop interrupt function and deceleration interrupt function, and control the robot to stop running or decelerate running according to different interrupt trigger sources;

[0014] Manually reset via the HMI interface to restore robot movement.

[0015] The interrupt stop function is specifically as follows:

[0016] The airborne radar trigger signal and the safety door opening signal are connected in parallel. When either signal is triggered, the stop operation interrupt signal output by the PLC control system is set. When the robot detects that the stop operation interrupt signal is "1", it immediately enters the stop operation interrupt and controls the robot to stop the current operation through the BRAKE instruction. The robot then repeatedly checks the stop operation interrupt signal until it is not "1". After a 1-second delay, it exits the interrupt.

[0017] The speed reduction interrupt function is specifically as follows:

[0018] The equipment radar trigger signal and the maintenance door opening signal are connected in parallel. When either signal is triggered, the deceleration interrupt signal output by the PLC control system is set for 2 seconds. After 2 seconds, the deceleration interrupt signal is automatically reset. When the robot detects that the deceleration interrupt signal is "1" and the stop interrupt has not been triggered, it immediately enters the deceleration interrupt and controls the robot's running rate OV_PRO by judging the value of the deceleration enable signal. When the deceleration interrupt signal is triggered, the robot's running rate OV_PRO is controlled by judging the value of the deceleration enable signal, so that the robot resumes its running speed.

[0019] The process of controlling the robot's operating rate OV_PRO by judging the value of the deceleration enable signal is as follows:

[0020] The PLC control system outputs a 2-second high-level pulse signal to trigger the robot to enter a deceleration interruption.

[0021] The deceleration enable signal is assigned a value by judging the maintenance door and the obstacle detected by the equipment radar: when any maintenance door is open or there is a target in the passage, the deceleration enable signal is set; when all maintenance doors are closed and there are no obstacles in the passage, the deceleration enable signal is reset.

[0022] When the deceleration trigger signal contains an open maintenance door or an obstacle detected by the equipment radar, the deceleration enable signal is considered to be "1". Conversely, when all maintenance doors are closed and no obstacles are detected by the equipment radar, the deceleration enable signal is "0". The PLC modifies the robot magnification parameter OV_PRO based on the detection results of the maintenance door and the equipment lidar when the deceleration interruption is triggered.

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

[0024] 1. This invention combines lidar with robots, and uses airborne radar to achieve dynamic safety protection for robots at different ground track positions.

[0025] 2. This invention uses equipment radar for full-coverage early warning of maintenance passages. By configuring multiple trigger signals of different lidars with different coverage areas, it realizes zoned monitoring of maintenance passages.

[0026] 3. This invention combines active and passive protection, which fully ensures the safe operation of the production line while adding the feature of online maintenance of the production line, thus balancing production efficiency and safety protection.

[0027] 4. This invention visualizes the trigger information of safety protection through the HMI human-machine interface, and is equipped with a convenient interruption protection recovery button, making the interaction between the production line and the user more user-friendly, and the operation safer and more efficient. Attached Figure Description

[0028] Figure 1 Safety protection layout diagram for a production line containing a seventh-axis robot;

[0029] Figure 2 A schematic diagram showing the configuration of the lidar detection area;

[0030] Figure 3 Flowcharts of sub-functions for robot stop interruption and deceleration interruption;

[0031] Figure 4 This relates to safety protection and control methods for production lines and robot operation procedures. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0033] As attached Figure 1As shown, the production line uses a safety fence for overall safety protection, enclosing the robot R, ground rails, aisles, and multiple pieces of equipment to achieve physical protection. The fence is equipped with four entrances / exits: Safety Door 1, Safety Door 2, Maintenance Door 1, and Maintenance Door 2, collectively referred to as protective doors. The protective doors are controlled by electronic locks, and the door lock opening and closing signals are connected to the PLC control system. When a piece of equipment malfunctions, maintenance personnel can enter the production line through the protective doors to check the corresponding equipment's program and perform repairs in the aisles.

[0034] The robot moves linearly back and forth on a track, reaching various equipment units to pick up, place, and replace workpieces, tools, and fixtures, ultimately facilitating the overall material flow of the production line. However, during these actions, the robot makes physical contact with the equipment, and its movement radius covers the aisle between the equipment and the track. This could potentially pose a significant safety hazard to personnel performing maintenance in the aisle.

[0035] To fully ensure a balance between production line safety and efficiency, the technical solution adopted in this invention is as follows:

[0036] The design of a safety protection control and production line operation interruption recovery method based on multiple lidar and multiple protective doors includes the following steps:

[0037] a) Use lidar for active protection and full-coverage early warning in corridor areas.

[0038] As attached Figure 1 As shown, a G10 LiDAR, referred to as an airborne LiDAR, is integrated on the robot side, with the radar's detection direction as indicated. When the robot moves along the track, the radar moves accordingly, detecting potential targets in the passageway between the robot and equipment in real time, thus achieving active protection of the passageway area.

[0039] Five ground-mounted lidar sensors, G01-G05, are integrated on the equipment side; these are referred to as the equipment lidar. The radar detection directions are as follows: Figure 1 As shown in the diagram (only the coverage area of ​​radar G04 is displayed; other radar devices are similar to G04), each lidar only detects the passageway area in front of its corresponding device. By combining and distributing all the radar devices, full coverage early warning of targets in the passageway can be achieved.

[0040] b) Integrate the opening of the protective door and the radar trigger signal into the PLC control system for classified control.

[0041] The safety doors have electronic lock signals, and the opening and closing signals of each safety door are connected to the PLC control system. Based on customer operating habits, the safety door positions are rationally arranged as follows: Safety door 1 is installed on the left side of the production line, directly opposite the aisle; safety door 2 is installed on the front of the production line, in the middle of one side of the robot's floor rail; and two maintenance doors are installed at the back of the production line, on one side of the equipment, between the pieces of equipment, as shown in the attached diagram. Figure 1 As shown.

[0042] The safety doors are conveniently located for operators to enter and exit the production line. They can be used for equipment inspections before production line startup and for stopping operation in case of emergencies. The door lock opening signal is connected to the PLC to trigger the robot to stop. The maintenance door is the back door of the production line. When a local production equipment malfunctions and the overall production line is not stopped, maintenance personnel can enter the production line through the maintenance door. The maintenance door opening signal is connected to the PLC to trigger the robot to slow down.

[0043] Similar to the two types of door lock signals, the trigger signals of lidar are also divided into: airborne radar trigger and equipment radar trigger. When the airborne radar identifies a target, that is, when a target is detected in the aisle where the robot is currently located, the robot stops running immediately; when the equipment radar identifies a target, that is, when a target exists at a location in the aisle other than the robot's current location, the robot is only triggered to slow down.

[0044] c) Add an interrupt handling function for the robot, which can trigger the robot to stop and slow down via the PLC.

[0045] The robot control uses a loop and switch-case program with branch selection and jump. When the robot receives a task number that matches the CASE enumeration, it can execute the corresponding action. After execution, it jumps back to the main loop.

[0046] Add interrupt initialization instructions to the robot program initialization section and enable interrupts 4 and 5. Interrupt 4 is defined as the stop interrupt Rob_stop(), triggered by the PLC output control point

[3019] ; interrupt 5 is defined as the slowdown interrupt Rob_slow(), triggered by the PLC output control point

[3020] . Interrupt 4 has a higher priority than interrupt 5. Write Rob_stop() and Rob_slow() functions respectively. When interrupt signals

[3019] and

[3020] are set, the robot will automatically jump to the corresponding sub-function through the interrupt enabled by the robot.

[0047] The `Rob_stop()` subfunction uses the `BRAKE` command to stop the robot, along with a loop to check the status

[3019] and a delay; the `Rob_slow()` subfunction checks the deceleration enable signal

[3021] and modifies the robot's running speed ratio `OV_PRO` parameter value to achieve deceleration. Figure 3 As shown.

[0048] d) Design a safety protection control and production line operation interruption recovery control method based on multiple lidar and multiple protective doors.

[0049] The airborne radar trigger signal and the safety door opening signal are connected in parallel. When either signal is triggered, the

[3019] signal output by the PLC is set. When the robot program detects that the

[3019] signal is "1", it immediately enters interrupt 4 and controls the robot to stop the current operation through the BRAKE instruction. It also repeatedly judges

[3019] to determine whether to jump out of the current sub-function.

[0050] The equipment radar trigger signal and the maintenance door opening signal are connected in parallel. When either signal is triggered, the

[3020] signal output by the PLC is set. When the robot program detects that the

[3020] signal is "1" and interrupt 4 is not triggered, it immediately enters interrupt 5. By judging the value of

[3021] , the robot's running rate OV_PRO is controlled, thereby realizing the robot's deceleration and speed recovery.

[0051] The PLC control system controls the movement of the ground rail and issues different task numbers to the robot, enabling the robot to move and execute corresponding actions at different equipment locations. In standby mode, the robot remains at the HMOE (Host Object Position) point. Based on the task requirements, the PLC first executes ground rail positioning to move the robot to the designated position. Once the ground rail is in position, the PLC executes the action corresponding to the task number. After completing the action, the robot returns to the HMOE point to prepare for the next task. This cycle repeats continuously. Figure 4 As shown.

[0052] When a stop interruption occurs, the robot immediately stops running. The operator needs to review and resolve the event that triggered the interruption (e.g., closing the safety door, removing the airborne radar intrusion target), and then manually reset the

[3019] signal on the HMI human-machine interface to resume operation. At this time, the robot will exit the Rob_stop() sub-function and return to the previous breakpoint to continue executing the next action.

[0053] When a speed reduction interruption occurs, the PLC control

[3020] outputs a 2-second high-level pulse signal, triggering the robot to enter interrupt 5. Simultaneously, the

[3021] signal is assigned a value based on the maintenance door and the target detected by the equipment radar. The

[3021] signal is set when any maintenance door is open or a target is present in the aisle; it is reset when all maintenance doors are closed and there is no target in the aisle. The robot enters the Rob_slow() subfunction via the

[3020] signal, modifies the robot's scaling parameter OV_PRO based on the

[3021] signal status, and performs either speed reduction or speed recovery. When a speed reduction interruption occurs, the robot immediately slows down, and the interrupt signal is reset after 2 seconds. After maintenance personnel resolve the fault, they need to close the maintenance door and manually trigger the

[3020] signal at the HMI (Human Machine Interface). The robot will then recover its running speed after interrupt 5 is executed.

[0054] First, the layout and installation of safety protection equipment were carried out, and the detection range of the lidar was configured to ensure that the lidar effectively covered the aisle area while shielding areas within the production line that might be accidentally triggered. Second, the trigger signals were connected to the PLC control system and classified for control. At the same time, service functions for robot interruption stop and interruption deceleration were developed and associated with the output signals of the PLC's classified control. Finally, the trigger signal display interface and operation buttons for resuming operation interruption were developed in the HMI human-machine interface.

[0055] The following is in conjunction with the appendix Figure 1-4 The present invention will be described in further detail as follows:

[0056] LiDAR can set the coverage area to any shape emanating from the center point. This invention sets the radar of each device into two rectangular areas, Zoo-1 and Zoo-2, as shown in the attached diagram. Figure 2 As shown in the attached diagram. First, the production line layout and installation are completed, and the effective coverage area of ​​the LiDAR is configured. The entire aisle area is divided into 10 independent monitoring zones using the equipment's LiDAR. The airborne LiDAR is only configured for these zones, without further zone division. Figure 1 As shown.

[0057] For detailed implementation steps, please refer to the appendix. Figure 4 To elaborate.

[0058] ① Complete the configuration and testing of safety door opening signals, maintenance door opening signals, equipment radar trigger signals, and airborne radar trigger signals;

[0059] ② Connect the above trigger signals to the PLC control system respectively, set the safety door opening signal and the airborne radar trigger signal as the stop operation interruption trigger source, and set the maintenance door opening signal and the equipment radar trigger signal as the speed reduction operation interruption trigger source;

[0060] ③ Configure the output points

[3019] and

[3020] for communication with the robot as the trigger control signals for stop interruption and deceleration interruption, respectively.

[3019] must be manually reset by the HMI, while

[3020] uses a 2-second high-level pulse signal and does not need to be reset. At the same time, configure

[3021] as a deceleration enable signal for judging the speed reduction and recovery.

[0061] ④ Develop display interfaces for each trigger signal in the HMI human-machine interface, and set operation buttons for operation interrupt recovery, including the

[3019] reset signal button for stopping interruption and the

[3020] high-level pulse button for triggering deceleration interruption;

[0062] ⑤ Develop the robot stop interrupt function, as shown in the attached document. Figure 3 As shown;

[0063] ⑥ Develop the robot deceleration interrupt function, as shown in the attached document. Figure 3 As shown;

[0064] ⑦ After the operator has dealt with the production line interruption fault, the production line can be restored to operation and the safety protection detection can be restarted through the manual recovery button of the HMI.

[0065] Through the above steps, during the robot's cyclical operation, under the effective safety protection equipment, different triggering interruptions are achieved under specific conditions, thereby meeting the protection requirements of safe production and taking into account production efficiency.

Claims

1. A safety protection and control method for a production line including a seventh-axis robot, characterized in that, Includes the following steps: A lidar is installed on the robot as an airborne lidar, so that it moves with the robot and can detect whether there are obstacles in the passageway in real time. Multiple lidars are installed between the production equipment and the passageway as equipment lidars, and each lidar detects in real time whether there are obstacles in the passageway in front of the corresponding production equipment. Connect the safety door opening signal, maintenance door opening signal, equipment radar trigger signal, and airborne radar trigger signal to the PLC control system respectively. Set the safety door opening signal and airborne radar trigger signal as stop operation interruption trigger sources, and set the maintenance door opening signal and equipment radar trigger signal as speed reduction operation interruption trigger sources. Construct robot stop interrupt function and deceleration interrupt function, and control the robot to stop running or decelerate running according to different interrupt trigger sources; Manually reset via the HMI interface to restore robot movement.

2. The safety protection and control method for a production line containing a seventh-axis robot according to claim 1, characterized in that, The interrupt stop function is specifically as follows: The airborne radar trigger signal and the safety door opening signal are connected in parallel. When either signal is triggered, the stop operation interrupt signal output by the PLC control system is set. When the robot detects that the stop operation interrupt signal is "1", it immediately enters the stop operation interrupt and controls the robot to stop the current operation through the BRAKE instruction. The robot then repeatedly checks the stop operation interrupt signal until it is not "1". After a 1-second delay, it exits the interrupt.

3. The safety protection and control method for a production line containing a seventh-axis robot according to claim 1, characterized in that, The speed reduction interrupt function is specifically as follows: The equipment radar trigger signal and the maintenance door opening signal are connected in parallel. When either signal is triggered, the deceleration interrupt signal output by the PLC control system is set for 2 seconds. After 2 seconds, the deceleration interrupt signal is automatically reset. When the robot detects that the deceleration interrupt signal is "1" and the stop interrupt has not been triggered, it immediately enters the deceleration interrupt and controls the robot's running rate OV_PRO by judging the value of the deceleration enable signal. When the deceleration interrupt signal is triggered, the robot's running rate OV_PRO is controlled by judging the value of the deceleration enable signal, so that the robot resumes its running speed.

4. The safety protection and control method for a production line containing a seventh-axis robot according to claim 3, characterized in that, The process of controlling the robot's operating rate OV_PRO by judging the value of the deceleration enable signal is as follows: The PLC control system outputs a 2-second high-level pulse signal to trigger the robot to enter a deceleration interruption. The deceleration enable signal is assigned a value by judging the maintenance door and the obstacle detected by the equipment radar: when any maintenance door is open or there is a target in the passage, the deceleration enable signal is set; when all maintenance doors are closed and there are no obstacles in the passage, the deceleration enable signal is reset. When the deceleration trigger signal contains an open maintenance door or an obstacle detected by the equipment radar, the deceleration enable signal is considered to be "1". Conversely, when all maintenance doors are closed and no obstacles are detected by the equipment radar, the deceleration enable signal is "0". The PLC modifies the robot magnification parameter OV_PRO based on the detection results of the maintenance door and the equipment lidar when the deceleration interruption is triggered.

5. A production line safety protection control system including a seventh-axis robot, used to implement the production line safety protection control method including a seventh-axis robot as described in claim 1, characterized in that, include: Safety fences, robots, ground tracks, passageways, multiple production equipment, multiple protective doors, and multiple LiDAR systems, including: The ground track, passageway, and multiple production devices are all located within a safety fence. The robot moves on the ground track, the passageway is located between the ground track and the production devices, the safety fence is equipped with multiple protective doors, and lidar is installed on the robot and between the production devices and the passageway.

6. A production line safety protection control system including a seventh-axis robot according to claim 5, characterized in that, The protective door is divided into a safety door and a maintenance door. The safety door is located on one side of the ground track and at least one end of the passageway, while the maintenance door is located on one side of the production equipment.

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