Automatic speed regulation chasing control system and method for friction lifting appliance
The automatic speed control system using sensors and a PLC controller solves the problems of low efficiency and equipment damage in friction spreader connections, achieving smooth spreader connection and high-efficiency production.
Patent Information
- Application Number
- CN202511825695.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-05
- Publication Date
- 2026-02-10
AI Technical Summary
In the existing technology, the connection method of front and rear friction lifting tools has the problem of affecting production efficiency or causing damage to the lifting tools and displacement of workpieces, especially when the lifting tools are stopped in the process section or when forced to connect under high and low speed differences.
Employing multiple sensors and a PLC controller, an automatic speed control system is implemented by detecting the position of the spreader and the status of the hook. The system uses a connecting device and an encoder to accurately measure distances and dynamically adjust the speed of the spreader to ensure coordinated connection of the spreaders.
It enables smooth connection of the lifting device during continuous operation in the process section, improves production efficiency and capacity, increases the connection success rate, and allows for manual intervention in case of failure to prevent the equipment problem from escalating.
Smart Images
Figure CN121493772A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of automobile production, in particular to a friction hanger automatic speed regulation chasing control system and method. BACKGROUND
[0002] The door line process section adopts a friction hanger as a carrier, and the front and rear friction hangers are connected in a hooking manner. The traditional connection mode of the front and rear friction hangers is as follows: 1. The process section hanger stops, and the chasing hanger runs together after connection; 2. The process section hanger runs, and the chasing hanger runs at high speed, and is connected by forced extrusion of the high and low speed difference. Both of the above modes have problems. For the first mode, the process section hanger needs to stop, which affects the production efficiency. For the second mode, impact will be generated, the hanger will be damaged, and the workpiece will be displaced, which affects the subsequent process. SUMMARY
[0003] The present application aims at the defects of the prior art, and provides a friction hanger automatic speed regulation chasing control system and method, which realizes hooking of the front and rear friction hangers in a running state.
[0004] In order to solve the above technical problems, on the one hand, the present application provides a friction hanger automatic speed regulation chasing control system, which comprises: a plurality of sensors for detecting the positions of the chasing hanger and the process section hanger on a running path and whether the hooking is completed; a connecting device for realizing automatic connection between the chasing hanger and the process section hanger; a PLC controller in communication with the plurality of sensors, for controlling the speed of the chasing hanger and the running of the process section hanger based on the positions detected by the sensors and whether the hooking is completed, so that the chasing hanger chases at a speed coordinated with the process section hanger and is connected.
[0005] In some embodiments, the plurality of sensors comprises, in sequence from the direction of the elevator to the process section, a counting start switch, a switching completion switch, a front deceleration switch, a front occupancy switch, an under-position waiting switch, a hooking detection switch and a chasing permission switch.
[0006] In some embodiments, the counting start switch is used to detect the entry and exit of the chasing hanger; the switching completion switch is used to detect the exit of the chasing hanger; the front deceleration switch is used to detect the entry of the chasing hanger; the front occupancy switch is used to detect the exit of the process section hanger and the entry of the chasing hanger; the under-position waiting switch is used to detect whether the chasing hanger successfully chases the process section hanger and completes the hooking; The hook detection switch is used to detect whether the hook of the catch-up spreader is hung on the process section spreader. The catch-up permission switch is used to detect whether the process section spreader reaches the preset position.
[0007] In some embodiments, the connecting device comprises a hook lifting plate arranged on the running path for automatically connecting the catch-up spreader and the process section spreader when their speeds match.
[0008] In some embodiments, the hook lifting plate comprises a first hook lifting plate arranged between the front occupancy switch and the under-position waiting switch for automatically connecting the catch-up spreader and the process section spreader when the catch-up spreader successfully catches up with the process section spreader, and a second hook lifting plate arranged between the under-position waiting switch and the hook detection switch for automatically connecting the catch-up spreader and the process section spreader when the catch-up spreader fails to catch up with the process section spreader.
[0009] In some embodiments, the PLC controller is used to: trigger counting of the front-end encoder and the tail-end encoder of the catch-up spreader according to the signal of the counting start switch; control the driving device of the catch-up spreader to shut down and initialize the data of the front-end encoder according to the signal of the switching completion switch; control the catch-up spreader to decelerate according to the signal of the front deceleration switch; control the catch-up spreader to lead out or stop according to the signal of the front occupancy switch; control the process section spreader to stop or continue running according to the signal of the under-position waiting switch; control the process section spreader to stop or continue running according to the signal of the hook detection switch; control whether the catch-up spreader starts to catch up according to the signal of the catch-up permission switch.
[0010] In another aspect, the application provides an automatic speed-adjusting catch-up control method for a friction spreader, comprising: S1, obtaining the signal of the front occupancy switch, and if the front occupancy switch detects that the process section spreader leaves, controlling the elevator to lead out the catch-up spreader; S2, controlling the catch-up spreader to walk in the direction of approaching the process section spreader at a preset initial speed; S3, obtaining the signal of the front occupancy switch, and if the front occupancy switch detects that the catch-up spreader enters, controlling the catch-up spreader to stop; S4, obtaining the signal of the catch-up permission switch, and if the catch-up permission switch detects that the process section spreader reaches the preset position, controlling the catch-up spreader to start to catch up according to the speed calculated according to the current process section beat; S5, adjust the speed of the chasing hoist according to the distance between the chasing hoist and the process section hoist, so as to match the speed of the process section hoist; obtain the signal of the under-position waiting switch, and judge whether the chasing hoist successfully catches up with the process section hoist and completes hooking; S6, obtain the signal of the hook detection switch, and judge whether the chasing hoist completes hooking; S7, obtain the signal of the switching completion switch, if the switching completion switch detects that the chasing hoist leaves, stop running the driving device of the chasing hoist, and complete the connection of the chasing hoist as a new process section hoist to perform the chasing connection of the next chasing hoist.
[0011] In some embodiments, step S2 comprises: obtaining the signal of the counting start switch, if the counting start switch detects that the leading end of the chasing hoist enters, controlling the leading end encoder of the chasing hoist to start counting.
[0012] In some embodiments, step S4 comprises: obtaining the signal of the counting start switch, if the counting start switch detects that the trailing end of the chasing hoist leaves, controlling the trailing end encoder of the chasing hoist to start counting.
[0013] In some embodiments, step S5 comprises: if the chasing hoist does not successfully catch up with the process section hoist and complete hooking, controlling the process section hoist to stop, controlling the chasing hoist to walk to a distance less than the connection distance from the process section hoist, controlling the process section hoist and the chasing hoist to run at the same speed, and connecting the chasing hoist and the process section hoist by the second hook lifting plate.
[0014] The present application has the following advantages: 1. The present application realizes the intelligentization and automation of the chasing process by the layout of multiple sensors and the accurate distance measurement and speed measurement of the encoder, realizes the automatic and smooth chasing and connection of the chasing hoist, and completes the entire connection process in the continuous running of the process section hoist, so that the vehicle door line can maintain continuous and efficient operation, and the overall production efficiency and capacity are improved.
[0015] 2. The time required for the chasing hoist to walk to the front occupation switch is less than the time required for the process section hoist to walk to the chasing permission switch, the chasing hoist is stopped at the front occupation switch, the chasing of the chasing hoist is controlled by the chasing permission switch, the chasing distance of each chasing hoist is ensured to be equal, which is conducive to improving the chasing precision and the one-time connection success rate of the chasing hoist and the process section hoist.
[0016] 3. The present application sets the first lifting hook plate and the second lifting hook plate, the first lifting hook plate is used for the first connection success of the chasing sling and the process section sling, if it fails to connect successfully, manual intervention can be carried out according to the signal of the under position waiting switch, so that the distance between the chasing sling and the process section sling meets the hook connection requirement, and the second lifting hook plate is used for automatic connection, thereby improving the secondary connection efficiency under the condition of unsuccessful first connection.
[0017] 4. The present application carries out double monitoring and verification on the connection process through the under position waiting switch and the hook detection switch, once the connection failure (such as signal interruption) is detected, the alarm can be triggered immediately and the system is stopped, manual intervention is informed, and the defects are prevented from flowing into the next station or causing greater equipment problems. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 It is a layout diagram of the vehicle door line of the present application; Figure 2 It is a schematic diagram of the arrangement of the sensor and the connecting device of the present application; Figure 3 It is a schematic diagram of the present application when the process section sling leaves the front occupancy switch; Figure 4 It is a schematic diagram of the present application when the chasing sling stops at the front station switch; Figure 5 It is a schematic diagram of the present application when the chasing sling catches up with the process section sling and connects by using the first lifting hook plate; Figure 6 It is a schematic diagram of the present application when the second lifting hook plate is used for connection; Figure 7 It is a schematic diagram of the present application when the chasing sling leaves the switching completion switch.
[0019] Reference signs: counting start switch 1; switching completion switch 2; front deceleration switch 3; front occupancy switch 4; under position waiting switch 5; hook detection switch 6; chasing permission switch 7; first lifting hook plate 8; second lifting hook plate 9; process section sling 10; chasing sling 11; elevator 12; degraded deceleration switch 13. DETAILED DESCRIPTION
[0020] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.
[0021] As shown in Figure 1 The vehicle door line of the present application includes a process section, an elevator 12 is arranged at the front end of the process section, the elevator 12 is used for guiding the chasing sling 11 out to the vehicle door line, This invention provides an automatic speed control and chasing control system for friction lifting devices, including sensors, connecting devices, and a PLC controller.
[0022] like Figure 2 As shown, the sensors and connecting devices are arranged at the front end of the process section. The sensors include, in sequence from the elevator 12 toward the process section, a counting start switch 1, a deceleration switch 13, a transfer completion switch 2, a forward deceleration switch 3, a forward occupancy switch 4, a short-position waiting switch 5, a hook detection switch 6, and a catch-up permission switch 7. Among them, the catch-up permission switch 7, the transfer completion switch 2, and the deceleration switch 13 are all square proximity switches; the counting start switch 1, the forward deceleration switch 3, the forward occupancy switch 4, the short-position waiting switch 5, and the hook detection switch 6 are all reflector-type proximity switches.
[0023] The counting start switch 1 is used to detect the entry and exit of the chasing hoist 11; The transfer completion switch 2 is used to detect the departure of the chasing lifting device 11; The front deceleration switch 3 is used to detect the entry of the chasing lifting device 11; The front occupancy switch 4 is used to detect the departure of the process section lifting device 10 and to catch up with the entry of the lifting device 11; The under-position waiting switch 5 is used to detect whether the chasing spreader 11 has successfully caught up with the process section spreader 10 and completed the hooking; The hook detection switch 6 is used to detect whether the hook of the chasing lifting device 11 is attached to the process section lifting device 10; The catch-up permission switch 7 is used to detect whether the process section lifting device 10 has reached the preset position; The deceleration switch 13 is used to detect the entry and exit of the chasing hoist 11.
[0024] Specifically, when the sensor changes from never detecting the spreader to continuously detecting the spreader, it indicates that the spreader has entered; when the sensor changes from continuously detecting the spreader to not detecting the spreader but detecting it again, it indicates that the spreader has left.
[0025] The PLC controller uses a Siemens 1517F programmable controller. The PLC controller is used for: The counting of the head encoder and tail encoder of the chasing hoist 11 is triggered according to the signal of the counting start switch 1; The signal from the transfer completion switch 2 controls the shutdown of the drive equipment of the chasing hoist 11 and initializes the data of the head encoder; The chasing hoist 11 decelerates according to the signal from the front deceleration switch 3; The chasing hoist 11 is controlled to extend or stop according to the signal from the front occupant switch 4; The process section lifting device 10 is controlled to stop or continue operation based on the signal from the under-position waiting switch 5; The signal from the hook detection switch 6 controls the stopping or continuing operation of the process section lifting device 10; The chasing device 11 is controlled to start chasing based on the signal from the chasing permission switch 7. The signal from the deceleration switch 13 is used to determine whether the chasing hoist 11 is slipping or has an encoder malfunction, thereby controlling the chasing hoist 11 to forcibly reduce its speed.
[0026] The lifting device of the present invention is used for lifting car doors, and includes a drive device that uses a Pepperl+Fuchs encoder and a Siemens G120 series frequency converter to adjust the drive speed.
[0027] The connecting device includes a hook lifting plate. A rotatable hook is provided at the front end of the lifting device. When the front end of the lifting device passes the hook lifting plate, the hook lifting plate causes the hook to rotate forward, and the hook automatically hooks into the hook hole at the rear end of the lifting device. The hook lifting plate of this invention includes a first hook lifting plate 8 and a second hook lifting plate 9. The first hook lifting plate 8 is arranged between the front occupancy switch 4 and the under-position waiting switch 5, and is used for automatic connection between the two when the chasing lifting device 11 successfully catches up with the upper process section lifting device 10. The second hook lifting plate 9 is arranged between the under-position waiting switch 5 and the hook detection switch 6, and is used for automatic connection between the two when the chasing lifting device 11 fails to catch up with the upper process section lifting device 10.
[0028] The control methods using the above-mentioned friction-based automatic speed control system for chasing and catching up include: S1, such as Figure 3 As shown, the signal of the front occupant switch 4 is obtained. If the front occupant switch 4 detects that the tail end of the process section lifting device 10 has left, the lifting device 11 is led out by the elevator 12. The chasing device 11 moves towards the process section lifting device 10 at a preset initial speed.
[0029] S2. Control the chasing lifting device 11 to move towards the process section lifting device 10 at a preset initial speed; acquire the signal from the counting start switch 1. If the counting start switch 1 detects the entry of the head end of the chasing lifting device 11, control the encoder at the head end of the chasing lifting device 11 to start counting. The encoder at the head end of the chasing lifting device 11 is used to detect the speed of the chasing lifting device 11 and the distance between the head end and the counting start switch 1. The speed and travel distance of the process section lifting device 10 are detected by the encoder at the tail end of the process section lifting device 10. When the process section lifting device 10 leaves the counting start switch 1, control the encoder at the tail end of the process section lifting device 10 to start counting. The encoder at the tail end of the process section lifting device 10 is used to detect the speed of the process section lifting device 10 and the distance between the tail end and the counting start switch 1. The difference between the distance detected by the encoder at the tail end of the process section lifting device 10 and the distance detected by the encoder at the head end of the chasing lifting device 11 is the distance between the process section lifting device 10 and the chasing lifting device 11.
[0030] The signal from the deceleration switch 13 is received. When the deceleration switch 13 detects the chasing spreader 11, it determines whether the chasing spreader 11 is slipping or has an encoder malfunction. If either slipping or encoder malfunction is met, the inverter is controlled to decelerate, requiring manual intervention. The method for determining slipping and encoder malfunction is as follows: the encoder value is checked to see if it is within a preset range. If it exceeds the preset range, the spreader is considered to be slipping and / or the encoder is malfunctioning. Under normal circumstances, the encoder value will be stable within a range. When the chasing spreader 11 slips, the encoder value is larger and exceeds the preset range. When the encoder malfunctions (e.g., network outage), the encoder value will be much larger than the value during normal operation. Therefore, by checking whether the encoder value is within the preset range, it is possible to determine whether slipping or encoder malfunction has occurred.
[0031] S3, such as Figure 4 As shown, the signal of the front occupant switch 4 is obtained. If the front occupant switch 4 detects that the chasing hoist 11 has entered, it controls the chasing hoist 11 to stop and waits for the chasing command from the controller. At this time, the chasing permission switch 7 has not yet been triggered, that is, the time required for the chasing hoist 11 to travel to the front occupant switch 4 is less than the time required for the process section hoist 10 to travel to the chasing permission switch 7.
[0032] S4. Obtain the signal from the catch-up permission switch 7. If the catch-up permission switch 7 detects that the process section lifting device 10 has reached the preset position, control the catch-up lifting device 11 to start catching up at the speed calculated according to the current process section cycle time. For example, when the process section cycle time is 75 JPH, the catch-up lifting device 11 starts catching up at a maximum speed of 50 Hz. The speed of the catch-up lifting device 11 is controlled by the frequency converter. The preset position is the position of the process section lifting device 10 when the catch-up permission switch 7 detects the boat-shaped plate in the middle of the process section lifting device 10.
[0033] The signal from the counting start switch 1 is obtained. If the counting start switch 1 detects that the tail end of the chasing device 11 has left, it controls the encoder at the tail end of the chasing device 11 to start counting. The counting can detect the distance between the tail end of the chasing device 11 and the counting start switch 1, and is used to guide the chasing of the next chasing device 11.
[0034] S5. Adjust the speed of the chasing lifting device 11 according to the distance between the chasing lifting device 11 and the process section lifting device 10 to match the speed of the process section lifting device 10. When the distance between the chasing lifting device 11 and the process section lifting device 10 is less than 20,000 Pulses (1m), control the frequency converter of the chasing lifting device 11 to decelerate. As the distance between the chasing lifting device 11 and the process section lifting device 10 gradually decreases, the speed difference between the chasing lifting device 11 and the process section lifting device 10 also gradually decreases. When the distance between the chasing lifting device 11 and the process section lifting device 10 is less than 500 Pulses, control the speed of the frequency converter of the chasing lifting device 11 to be consistent with the speed of the frequency converter of the process section lifting device 10.Figure 5 As shown, at this time, the chasing lifting device 11 will automatically connect with the process section lifting device 10 through the first lifting hook plate 8; If the signal of the waiting switch 5 is obtained, it is determined whether the chasing spreader 11 has successfully caught up with the process section spreader 10 and completed the hooking. If the waiting switch 5 continues to issue a signal and the continuous signaling time is greater than the time required for the process section spreader 10 to enter and leave the waiting switch 5, it means that the chasing spreader 11 has successfully caught up with the process section spreader 10 and completed the hooking. If the signal from the waiting switch 5 is interrupted, it indicates that the chasing spreader 11 has not completed hooking. An alarm is triggered, and manual intervention is required. The process section spreader 10 is stopped, and the chasing spreader 11 is moved until the distance between it and the process section spreader 10 is less than the connection distance. The process section spreader 10 and the chasing spreader 11 are then moved at the same speed, and the second hook lifting plate 9 is used to connect the chasing spreader 11 and the process section spreader 10. Figure 6 As shown.
[0035] S6. Obtain the signal from the hook detection switch 6 and determine whether the chasing lifting device 11 has completed hooking. If the hook detection switch 6 continues to issue a signal, it means that hooking has been completed. Otherwise, the chasing lifting device 11 and the process section lifting device 10 stop running and alarm, and manual handling is required. S7, such as Figure 7 As shown, the signal of the transfer completion switch 2 is obtained. If the transfer completion switch 2 detects that the chasing hoist 11 has left, the drive device of the chasing hoist 11 is stopped. The chasing hoist 11 moves together with the drive device of the process section hoist 10.
[0036] Using the completed catch-up lifting device 11 as the new process segment lifting device 10, the next catch-up lifting device 11 is connected, and steps S1 to S7 are repeated.
[0037] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.
Claims
1. An automatic speed regulation and chasing control system for friction lifting devices, characterized in that, include: Multiple sensors are used to detect the position of the chasing hoist (11) and the process section hoist (10) on the running path and whether the hooking is completed; A connecting device is used to realize the automatic connection between the chasing hoist (11) and the process section hoist (10); The PLC controller communicates with multiple sensors to control the speed of the chasing hoist (11) and the operation of the process section hoist (10) based on the position detected by the sensors and whether the hooking is completed, so that the chasing hoist (11) chases and connects at a speed coordinated with the process section hoist (10).
2. The automatic speed regulation and chasing control system for friction lifting devices according to claim 1, characterized in that, The multiple sensors include a counting start switch (1), a transfer completion switch (2), a front deceleration switch (3), a front occupancy switch (4), a vacancy waiting switch (5), a hook detection switch (6), and a catch-up allow switch (7), arranged sequentially from the elevator (12) toward the process section.
3. The automatic speed regulation and chasing control system for friction lifting devices according to claim 2, characterized in that, The counting start switch (1) is used to detect the entry and exit of the chasing hoist (11); The transfer completion switch (2) is used to detect the departure of the chasing hoist (11); The front deceleration switch (3) is used to detect the entry of the chasing hoist (11); The front occupancy switch (4) is used to detect the departure of the process section lifting device (10) and the entry of the chasing lifting device (11); The under-position waiting switch (5) is used to detect whether the catching-up lifting device (11) has successfully caught up with the process section lifting device (10) and completed the hooking; The hook detection switch (6) is used to detect whether the hook of the chasing hoist (11) is attached to the process section hoist (10). The catch-up permission switch (7) is used to detect whether the process section lifting device (10) has reached the preset position.
4. The automatic speed regulation and chasing control system for friction lifting devices according to claim 3, characterized in that, The connecting device includes a hook plate arranged on the running path for automatically connecting the chasing hoist (11) and the process section hoist (10) when their speeds match.
5. The automatic speed regulation and chasing control system for friction lifting devices according to claim 4, characterized in that, The lifting plate includes a first lifting plate (8) and a second lifting plate (9). The first lifting plate (8) is arranged between the front occupancy switch (4) and the under-position waiting switch (5) for automatic connection when the chasing lifting device (11) successfully catches up with the upper process section lifting device (10). The second lifting plate (9) is arranged between the under-position waiting switch (5) and the hook detection switch (6) for automatic connection when the chasing lifting device (11) fails to catch up with the upper process section lifting device (10).
6. The automatic speed regulation and chasing control system for friction lifting devices according to claim 3, characterized in that, The PLC controller is used for: The counting of the front and rear encoders of the chasing hoist (11) is triggered by the signal of the counting start switch (1); The signal from the transfer completion switch (2) controls the shutdown of the drive device of the chasing hoist (11) and initializes the data of the head encoder; The chasing hoist (11) is decelerated according to the signal of the front deceleration switch (3); The chasing hoist (11) is controlled to extend or stop according to the signal of the front occupant switch (4); The process section lifting device (10) is controlled to stop or continue operation according to the signal of the under-position waiting switch (5); The process section lifting device (10) is controlled to stop or continue operating according to the signal of the hook detection switch (6); The chasing device (11) is controlled to start chasing based on the signal from the chasing permission switch (7).
7. A method for automatic speed regulation and chasing control of a friction lifting device, characterized in that, include: S1. Obtain the signal from the front occupant switch (4). If the front occupant switch (4) detects that the process section lifting device (10) has left, control the elevator (12) to bring out the chasing lifting device (11). S2. Control the chasing lifting device (11) to move towards the lifting device (10) of the process section at a preset initial speed; S3. Obtain the signal from the front occupant switch (4). If the front occupant switch (4) detects that the chasing hoist (11) has entered, control the chasing hoist (11) to stop. S4. Obtain the signal of the catch-up permission switch (7). If the catch-up permission switch (7) detects that the process section lifting device (10) has reached the preset position, control the catch-up lifting device (11) to start catching up according to the speed calculated based on the current process section cycle. S5. Adjust the speed of the chasing lifting device (11) according to the distance between the chasing lifting device (11) and the process section lifting device (10) to match the speed of the process section lifting device (10); obtain the signal of the under-position waiting switch (5) and determine whether the chasing lifting device (11) has successfully caught up with the process section lifting device (10) and completed the hooking. S6. Obtain the signal from the hook detection switch (6) and determine whether the chasing lifting device (11) has completed hooking; S7. Obtain the signal from the transfer completion switch (2). If the transfer completion switch (2) detects that the chasing lifting device (11) has left, stop running the driving device of the chasing lifting device (11) and use the completed chasing lifting device (11) as the new process section lifting device (10) to carry out the chasing connection of the next chasing lifting device (11).
8. The automatic speed regulation and chasing control method for friction lifting devices according to claim 7, characterized in that, Step S2 includes: obtaining the signal of the counting start switch (1); if the counting start switch (1) detects the entry of the head end of the chasing hoist (11), then controlling the encoder at the head end of the chasing hoist (11) to start counting.
9. The automatic speed regulation and chasing control method for friction lifting devices according to claim 7, characterized in that, Step S4 includes: obtaining the signal of the counting start switch (1); if the counting start switch (1) detects that the tail end of the chasing hoist (11) has left, then controlling the tail end encoder of the chasing hoist (11) to start counting.
10. The automatic speed regulation and chasing control method for friction lifting devices according to claim 7, characterized in that, Step S5 includes: if the chasing lifting device (11) fails to catch up with the process section lifting device (10) and complete the hooking, then control the process section lifting device (10) to stop, control the chasing lifting device (11) to move until the distance between it and the process section lifting device (10) is less than the connection distance, control the process section lifting device (10) and the chasing lifting device (11) to run at the same speed, and use the second hook lifting plate (9) to connect the chasing lifting device (11) and the process section lifting device (10).