CN118833730A - Crown block control system - Google Patents

Abstract

The application belongs to the field of semiconductor material transmission, and discloses a crown block control system, wherein photoelectric switches are arranged at two ends of each track section to detect whether a non-connected crown block exists in each track section, so that the track section with the non-connected crown block is avoided when a transportation path is planned, and the crown block control system is matched with the speed control of the crown block, so that collision among crown blocks can be reliably prevented; in addition, because the control processing functions except the allocation transportation tasks and the planning transportation paths are put down in other equipment, the pressure of the central dispatching server can be relieved, and the performance requirement of the central dispatching server is reduced, wherein the speed control right is put down to the crown block, the speed of the crown block for responding to special conditions can be improved, and the safety is further improved.

Description

A kind of overhead crane control system

Technical Field

The present application relates to the technical field of semiconductor material transmission, and in particular to an overhead crane control system.

Background Art

As the size of wafers increases, overhead cranes are almost always used for transporting semiconductor materials. The commonly used method for controlling overhead cranes is to rely on a master server, which performs real-time scheduling, plans the path of each vehicle, controls each vehicle to accelerate and decelerate according to preset parameters and motion programs, and uses sensors installed in front and behind the overhead cranes for anti-collision detection to ensure the safety of the overhead crane operation. However, as the scale of wafer fabs expands, the overhead cranes can reach more locations, the map scale is larger, and the number of overhead cranes is greater. Traditional anti-collision methods and overhead crane control methods can no longer meet performance requirements.

Chinese patent CN117263037B proposes a method for controlling an overhead crane, which uses the position and speed parameters of the overhead crane in the track, combined with map information, to trigger real-time path planning in each track segment, and analyzes the situation of the next connection point to control the speed in advance, so as to make up for the shortcomings of the sensor and reduce the loss of the overhead crane motor system caused by frequent acceleration and deceleration. However, for large-scale wafer fabs, due to the large number of overhead cranes and the large and complex map scale, it is very likely that multiple vehicles will enter the track of the next stage at the same time, thereby triggering real-time path planning scheduling at the same time, which is a great challenge to the computing power and scheduling of the server. It is easy to cause the control of the overhead crane to lag due to the long calculation time, and it is impossible to make advance predictions. In addition, since the dominant core of this control method is in the main server, the overhead crane itself only has the functions of obedience and reporting. Although it can reduce the hardware cost of the overhead crane control system, the overly complex map makes the main service calculation more prone to errors, and the active control ability of the overhead crane is weak. In addition, as the map scale expands, there will generally be more long straight tracks. If each track segment is still taken as the minimum calculation degree according to the control method of this patent, although the screening amount will be less, a lot of unnecessary calculations will be added, wasting computing power.

Summary of the invention

The purpose of the present application is to provide an overhead crane control system that can reliably prevent overhead crane collisions and relieve the pressure on a central dispatching server.

The present application provides an overhead travelling vehicle control system, comprising a central dispatching server, a map information database, a track information acquisition processor and a plurality of overhead travelling vehicles arranged on a track, the track comprising a plurality of track segments;

The central dispatch server is used to assign transportation tasks to the overhead crane and plan a transportation route for the overhead crane;

The map information database is used to record map information and crane information of each crane; the crane information includes position and speed;

The track information acquisition processor is used to record the entry and exit information of the overhead crane in and out of each track segment in real time according to the photoelectric switches arranged at both ends of each track segment, detect whether there is a lost overhead crane in each track segment according to the map information, the overhead crane information and the entry and exit information, and send warning information to the map information database when a lost overhead crane is detected, so that the map information database marks the corresponding track segment, thereby allowing the central dispatch server to avoid the corresponding track segment when planning the transportation route;

The overhead crane is used to obtain its own overhead crane information according to the marking points arranged at intervals on the track and upload it to the map information database to update the overhead crane information, and control its own speed according to the map information and the overhead crane information.

The overhead crane control system sets photoelectric switches at both ends of each track section to detect whether there is a lost overhead crane in each track section, so as to avoid the track section with the lost overhead crane when planning the transportation route. At the same time, in conjunction with the speed control of the overhead crane itself, collisions between overhead cranes can be reliably prevented. In addition, since the control processing functions other than allocating transportation tasks and planning transportation routes are delegated to other devices, the pressure on the central dispatching server can be relieved and the performance requirements of the central dispatching server can be reduced. Among them, delegating the speed control right to the overhead crane itself can also increase the speed at which the overhead crane responds to special situations, further improving safety.

Preferably, when the overhead travelling vehicle obtains its own overhead travelling vehicle information according to identification points arranged at intervals on the track, the overhead travelling vehicle executes:

Each time the vehicle passes through a marking point, the marking information of the marking point is identified, and the marking position is extracted therefrom as the position in the vehicle's own crane information, and the vehicle's own speed is obtained through a sensor as the speed in the vehicle's own crane information.

Preferably, the identification points include landmark points and key points, the landmark points are arranged at equal intervals on each straight track segment, and the key points include straight points, limit points, departure points, positioning points, early deceleration points and stop deceleration points;

The straight line point is used to indicate that the downstream of the corresponding key point of the overhead travelling crane is a straight track section that allows acceleration to the maximum speed;

The limiting point is used to indicate that the position of the corresponding key point of the overhead travelling crane is the starting point of the curved track segment;

The disengagement point is used to indicate that the position of the corresponding key point of the overhead travelling crane is the end point of the curved track segment;

The positioning point is used to prompt the overhead crane to perform precise positioning and stop operation so as to stop at the loading and unloading position;

The advance deceleration point is used to prompt that the overhead travelling crane is about to enter a curved track section;

The stop and deceleration point is used to prompt that the overhead travelling crane is about to reach the positioning point.

Waypoints can be used to assist the overhead crane in locating its own position, and key points can be used to assist the overhead crane in speed control, which is beneficial to ensuring the safe operation of the overhead crane and accurately reaching the target loading and unloading position, and is beneficial to improving the overall transportation efficiency of the overhead crane group.

Preferably, the map information includes a unidirectional graph structure, and the unidirectional graph structure is used to record the upstream and downstream relationships between the identification points.

Preferably, when the overhead crane controls its own speed according to the map information and the overhead crane information, the overhead crane performs:

If no transport task is received, the vehicle moves along a preset patrol route and controls its speed according to the map information and the overhead crane information during the movement;

If a transport task is received, the vehicle moves along the corresponding transport route and controls its speed according to the map information and the overhead crane information during the movement.

When no transport mission is received, the overhead crane is ordered to patrol according to the preset patrol route, which can effectively avoid congestion caused by the overhead crane without a mission.

Preferably, the overhead crane controls its own speed according to the map information and the overhead crane information during movement, specifically performing:

A1. Initialize the control mode of the overhead crane to the early warning mode;

A2. If the current control mode of the overhead crane is the early warning mode, the speed of the crane is adjusted according to the type of key points detected, and the early warning distance is determined in real time according to the crane information to switch the control mode; the control modes include the following mode, the avoidance mode and the early warning mode;

A3. If the current control mode of the overhead crane is the following mode, the speed of the crane is adjusted according to the speed of the preceding vehicle to follow the preceding vehicle until the first preset condition is met, then the control mode of the overhead crane is switched to the warning mode and the process returns to step A2;

A4. If the current control mode of the overhead crane is the avoidance mode, the speed of the crane is adjusted according to the avoidance rule until the second preset condition is met, the control mode of the overhead crane is switched to the warning mode, and the process returns to step A2.

Preferably, in step A2, adjusting the movement speed of the self according to the type of the detected key point specifically includes:

Determine the key points related to the current driving path of the overhead crane as relevant key points;

When the relevant key point is detected, determining the type of the detected relevant key point;

If the detected relevant key point is a straight line point or a separation point, the target speed of the overhead crane is set to the maximum moving speed, and the acceleration of the overhead crane is set to the maximum acceleration;

If the detected relevant key point is an early deceleration point, the target speed of the overhead crane is set to the preset maximum turning speed, and the acceleration of the overhead crane is set to the maximum deceleration;

If the detected relevant key point is a limit point, the speed of the overhead crane is set to be no higher than the maximum turning speed;

If the detected relevant key point is a stop deceleration point, the target speed of the overhead crane is set to the preset minimum moving speed, and the acceleration of the overhead crane is set to the maximum deceleration;

If the detected relevant key point is a positioning point, a precise positioning stop operation is performed to stop at the target loading and unloading position.

Preferably, in step A2, determining the warning distance in real time according to the overhead travelling vehicle information thereof specifically includes:

The warning distance is calculated according to the speed in the overhead crane information of the vehicle.

Preferably, in step A2, the process of controlling the mode switching includes:

According to the map information and the position in the overhead crane information of the own overhead crane, determining whether there is a junction within the warning distance in front of the own overhead crane;

If there is no junction within the warning distance in front of the overhead crane and there are other overhead cranes within the warning distance in front of the overhead crane, the control mode of the overhead crane is switched to the following mode;

If there is no junction within the warning distance in front of the overhead crane and there is no other overhead crane within the warning distance in front of the overhead crane, the control mode of the overhead crane is maintained in the warning mode;

If there is a junction within the warning distance in front of the overhead crane, the overhead crane does not need to pass through the curved track section when passing through the junction, and there are other overhead cranes within the warning distance in front of the overhead crane, the control mode of the overhead crane is switched to the following mode;

If there is a junction within the warning distance in front of the overhead crane, the overhead crane does not need to pass through the curved track section when passing through the junction, and there is no other overhead crane within the warning distance in front of the overhead crane, the control mode of the overhead crane is maintained in the warning mode;

If there is a junction within the warning distance in front of the overhead crane, the overhead crane needs to pass through a curved track section to pass through the junction, and there are other overhead cranes between the overhead crane and the junction, the control mode of the overhead crane is switched to a following mode;

If there is a junction within the warning distance in front of the overhead crane, the overhead crane needs to pass through a curved track section to pass through the junction, there is no other overhead crane between the overhead crane and the junction, and there is another overhead crane within the reference warning distance behind the straight road of the junction, the control mode of the overhead crane is switched to the avoidance mode;

If there is a junction within the warning distance in front of the overhead crane, the overhead crane needs to pass through a curved track section to pass through the junction, there is no other overhead crane between the overhead crane and the junction, there is no other overhead crane within the reference warning distance behind the straight road of the junction, and there is another overhead crane within the reference warning distance in front of the straight road of the junction, then the control mode of the overhead crane is switched to the following mode;

If there is a junction within the warning distance in front of the overhead crane, the overhead crane needs to pass through a curved track section to pass through the junction, there are no other overhead cranes between the overhead crane and the junction, there are no other overhead cranes within the reference warning distance behind the straight road of the junction, and there are no other overhead cranes within the reference warning distance in front of the straight road of the junction, then the control mode of the overhead crane is maintained in the warning mode.

Preferably, the reference warning distance is a braking distance required for the overhead crane to decelerate from a maximum moving speed to a stop at a maximum deceleration.

Beneficial effects: The overhead crane control system provided by the present application, by setting photoelectric switches at both ends of each track segment to detect whether there is a lost overhead crane in each track segment, thereby avoiding the track segment with the lost overhead crane when planning the transportation route, and at the same time cooperating with the speed control of the overhead crane itself, it can reliably prevent collisions between overhead cranes; in addition, since the control processing functions other than allocating transportation tasks and planning transportation routes are delegated to other devices, the pressure on the central dispatching server can be relieved and the performance requirements of the central dispatching server can be reduced. Among them, delegating the speed control right to the overhead crane itself can also increase the speed at which the overhead crane responds to special situations, further improving safety.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the structure of an overhead traveling crane control system provided in an embodiment of the present application.

FIG. 2 is a diagram of an exemplary track distribution.

FIG. 3 is a schematic diagram of a junction.

FIG. 4 is an exemplary diagram showing the marking result of a track segment marked with a lost overhead travelling vehicle.

FIG5 is a flow chart of the speed control of the overhead crane.

FIG. 6 is a flow chart of adjusting the motion speed according to the detected key points.

FIG. 7 is a schematic diagram showing the principle of the control mode switching process.

Explanation of reference numerals: 1. Central dispatching server; 2. Map information database; 3. Track information acquisition processor; 4. Overhead crane; 5. Bus; 90. Track; 91. Identification point.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

Please refer to FIG. 1 , which is a diagram of an overhead crane control system in some embodiments of the present application, including a central dispatching server 1, a map information database 2, a track information acquisition processor 3, and a plurality of overhead cranes 4 arranged on a track 90 that are communicatively connected to each other; the track 90 includes a plurality of track segments (including straight track segments and curved track segments, for example, a in FIG. 2 is a straight track segment, and b is a curved track segment);

The central dispatch server 1 is used to assign transportation tasks to the overhead crane 4 and plan transportation routes for the overhead crane 4;

The map information database 2 is used to record map information and crane information of each crane 4; the crane information includes position and speed;

The track information acquisition processor 3 is used to record the entry and exit information of the overhead crane 4 in and out of each track segment in real time according to the photoelectric switches set at both ends of each track segment, detect whether there is a lost overhead crane in each track segment according to the map information, the overhead crane information and the entry and exit information, and send a warning message to the map information database 2 when a lost overhead crane is detected, so that the map information database 2 marks the corresponding track segment (i.e., the track segment where the lost overhead crane exists), so that the central dispatch server 1 avoids the corresponding track segment when planning the transportation route;

The overhead crane 4 is used to obtain its own overhead crane information according to the marking points arranged at intervals on the track 90 and upload it to the map information database 2 to update the overhead crane information, and control its own speed according to the map information and the overhead crane information.

The crane control system sets photoelectric switches at both ends of each track segment to detect whether there is a lost crane in each track segment, thereby avoiding the track segment with a lost crane when planning the transportation route, and at the same time, in conjunction with the speed control of the crane 4 itself, it can reliably prevent collisions between cranes 4; in addition, since the control processing functions other than the allocation of transportation tasks and planning of transportation routes are delegated to other devices, the pressure on the central dispatch server 1 can be relieved and the performance requirements of the central dispatch server 1 can be reduced. Among them, delegating the speed control right to the crane 4 itself can also increase the speed of the crane 4 in responding to special situations, further improving safety. Therefore, the crane control system is particularly suitable for use in large-scale map scenarios of large-scale wafer factories, and can overcome the problem that traditional anti-collision methods and crane control methods are difficult to meet performance requirements in large-scale map scenarios of large-scale wafer factories.

The central dispatch server 1 , the map information database 2 , the track information acquisition processor 3 and the overhead travelling vehicle 4 may be connected in communication via a bus 5 , but not limited thereto, as shown in FIG. 1 .

The central dispatch server 1 may use existing task allocation algorithms and existing path planning algorithms to allocate transport tasks and plan transport paths, which are not limited herein. The map information and the crane information of each crane 4 (mainly the position of each crane 4) required for allocating transport tasks and planning transport paths may be retrieved from the map information database 2.

The map information database 2 can also record the transport task list and transport path information. The transport task list is used to record the transport task allocation results. The transport path information includes the path information of the transport path corresponding to each transport task. When the selected task allocation algorithm and path planning algorithm need to use the transport task list and transport path information, the central dispatch server 1 can extract the corresponding data from the map information database 2, and there is no need to store it in the central dispatch server 1 for a long time, saving the storage space of the central dispatch server 1.

The entry and exit information of the overhead crane 4 entering and exiting each track segment includes the number of overhead cranes entering each track segment (recorded as the entry number) and the number of overhead cranes leaving each track segment (recorded as the exit number). The entry number is equal to the number of triggering times of the photoelectric switch at the starting end of the corresponding track segment, and the exit number is equal to the number of triggering times of the photoelectric switch at the ending end of the corresponding track segment. When the track information acquisition processor 3 detects whether there is a lost overhead crane in each track segment based on the map information, overhead crane information and entry and exit information, it executes:

The difference between the number of entry and the number of exit of each track segment is calculated as the number of overhead cranes 4 currently existing in each track segment, which is recorded as the first real-time overhead crane number;

Acquire the latest map information and overhead travelling vehicle information from the map information database 2;

According to the acquired map information and the position in the overhead crane information, the number of overhead cranes 4 currently located in each track segment is determined, and recorded as the second real-time overhead crane number;

The first real-time number of overhead cranes and the second real-time number of overhead cranes of each track section are compared, and the track section where the first real-time number of overhead cranes and the second real-time number of overhead cranes are not equal is determined to be the track section with the lost overhead crane.

The loss of connection of Overhead Crane 4 is mainly caused by the failure of Overhead Crane 4. Overhead Crane 4 will perform self-inspection in real time (including the detection of communication connection status with other equipment and the detection of operation status of internal equipment of Overhead Crane 4, etc.), and will stop moving when a failure is detected to avoid the incorrect control process of continuing the movement and affecting the normal operation of itself and other Overhead Cranes. Therefore, once Overhead Crane 4 loses connection in a certain track section, it will cause congestion of the track section, so that the central dispatching server 1 needs to avoid the corresponding track section when planning the transportation route later, so as to avoid guiding other Overhead Cranes to the congested track section.

In addition, the track information collection processor 3 is also used to send a prompt message to the central dispatch server 1 when a lost overhead crane is detected, so that the central dispatch server 1 can adjust the driving path (transportation path and patrol path are collectively referred to as driving path, and the introduction of patrol path is described later) of each overhead crane 4. After the central dispatch server 1 completes the adjustment of the driving path of each overhead crane 4, it will send the adjusted driving path to each overhead crane 4 and send it to the map information database 2 for data update.

Among them, when the map information database 2 marks the corresponding track segment, it can be marked by adjusting the color of the corresponding track segment (for example, the map information includes a track map, and the color of the corresponding track segment in the track map is adjusted to a first preset color, such as red, but not limited to this. As shown in Figure 4, d and e are track segments marked as having lost connection with the overhead travelling vehicle), or each track segment can be numbered in advance, and the number of the corresponding track segment is added to the blocked section number set to achieve marking; but the specific marking method is not limited to this.

Among them, identification points 91 can be arranged at intervals on the track 90, and an identification module for identifying the identification points 91 can be arranged on the overhead travelling vehicle 4. The positions of the identification points 91 (hereinafter referred to as identification positions) can be accurately measured in advance. When the overhead travelling vehicle 4 moves to the point where the identification module is aligned with the identification point 91, the corresponding identification point 91 can be detected, thereby extracting the identification position of the corresponding identification point 91 as the position of the overhead travelling vehicle 4, so as to realize the positioning of the overhead travelling vehicle 4. For example, an RFID tag can be used as the identification point 91, and an RFID data reader can be used as the identification module, but it is not limited thereto; wherein, the RFID tag can record identification information, for example, the identification information includes the type of the identification point 91 (the type of the identification point 91 is described later) and the identification position, but it is not limited thereto, and the RFID data reader can read the RFID tag to obtain the corresponding identification information.

A sensor may be provided on the overhead crane 4 to measure its own speed in real time, for example, a rotary encoder may be used to measure its own speed, but the invention is not limited thereto.

Therefore, when the overhead crane 4 obtains its own overhead crane information according to the identification points 91 arranged at intervals on the track 90, it executes:

Each time a marking point 91 is passed, the marking information of the marking point 91 is identified, and the marking position is extracted therefrom as the position in the own overhead traveling vehicle information, and the own speed is obtained through the sensor as the speed in the own overhead traveling vehicle information.

Therefore, each time the overhead crane 4 passes through a marking point 91, it sends its own overhead crane information to the map information database 2, so that the map information database 2 updates the overhead crane information.

In fact, the positioning of the overhead crane 4 is not limited to using the marking points 91 , and a positioning module may be provided on the overhead crane 4 to measure the position of the overhead crane 4 using the positioning module.

In this embodiment, the identification points 91 include landmark points and key points. The landmark points are arranged at equal intervals on each straight track segment. The key points include straight points, restriction points, departure points, positioning points, early deceleration points and stop deceleration points.

Among them, the straight point is used to indicate that the downstream of the corresponding key point of the overhead crane 4 is a straight track segment that is allowed to accelerate to the maximum speed. Generally, when the length of a straight track segment is not less than a preset length threshold (determined according to the actual acceleration and deceleration performance of the overhead crane 4), a straight point is set at the starting end of the straight track segment. When the overhead crane 4 detects the straight point, it can accelerate to the maximum speed at the maximum acceleration (the maximum acceleration is the maximum acceleration that the overhead crane 4 can reach, and the maximum speed is the maximum speed that the overhead crane 4 can reach), thereby improving the transportation efficiency.

Among them, the limit point is used to prompt the position of the corresponding key point of the overhead crane 4 to be the starting point of the curved track section. In order to ensure the safety of the overhead crane 4 passing through the curved track section, it is necessary to limit the moving speed of the overhead crane 4 in the curved track section. The limit point is used to prompt the overhead crane 4 that it has entered the curved track section so that the overhead crane 4 can limit the speed below the preset maximum turning speed (which can be set according to actual needs). A limit point is set at the starting end of each curved track section.

The disengagement point is used to indicate that the position of the corresponding key point of the overhead crane 4 is the end point of the curved track segment. In order to ensure transportation efficiency, the overhead crane 4 can accelerate after leaving the curved track segment, and the disengagement point indicates that the overhead crane 4 has left the curved track segment, thereby accelerating the overhead crane 4. A disengagement point is set at the end of each curved track segment.

Among them, the positioning point is used to prompt the crane 4 to perform precise positioning and stop operation to stop at the loading and unloading position. Among them, the loading and unloading position is the position corresponding to each loading and unloading station on the wafer production line. For example, c in Figure 2 is a wafer production line device, and each wafer production line device has a corresponding loading and unloading station, so that a corresponding positioning point is set for each wafer production line device. Specifically, a positioning point is set at the preset parking distance upstream of each loading and unloading position. The preset parking distance is generally set according to the preset minimum moving speed. In some preferred embodiments, the crane 4 is required to decelerate to the preset minimum moving speed (which can be set according to actual needs) before reaching the positioning point. After reaching the positioning point, the position control mode will be used to control the position of its own travel servo motor (the crane 4 is driven by the travel servo motor) so that the crane 4 continues to move the preset parking distance and then stops. Since the position control mode can realize the precise control of the moving distance, it can ensure that the crane 4 stops accurately at the loading and unloading position (the stop position error of this method can reach within ±0.5mm).

The advance deceleration point is used to remind the crane 4 that it is about to enter the curved track section. If the crane 4 starts to decelerate after entering the curved track section, it will not be able to decelerate to below the preset maximum turning speed in time and it is difficult to ensure safety. For this reason, an advance deceleration point can be set upstream of each restriction point to remind the crane 4 that it is about to enter the curved track section, so as to start decelerating. The interval between the upstream advance deceleration point and the restriction point can be set according to the deceleration performance of the crane 4, the preset maximum turning speed and the maximum speed of the crane 4, so as to ensure that the crane 4 can decelerate from the maximum speed to the preset maximum turning speed within the interval.

Among them, the stop deceleration point is used to prompt the crane 4 to reach the positioning point. Since the crane 4 needs to decelerate to the preset minimum moving speed before reaching the positioning point, it is necessary to set a corresponding stop deceleration point at the upstream of each positioning point to prompt the crane 4 to decelerate to the preset minimum moving speed, wherein the interval between the stop deceleration point and the corresponding positioning point can be set according to the deceleration performance of the crane 4, the maximum speed of the crane 4 and the preset minimum moving speed, so as to ensure that the crane 4 can decelerate from the maximum speed to the preset minimum moving speed within the interval. Since whether the crane 4 can accurately reach the preset minimum moving speed when it reaches the positioning point will affect whether the final stop position of the crane 4 accurately reaches the corresponding loading and unloading position, therefore, after reaching the stop deceleration point, the crane 4 will use the speed control mode to control the speed of its own travel servo motor, so that the moving speed of the crane 4 accurately reaches and remains at the preset minimum moving speed until it reaches the positioning point.

Among them, since the distribution of key points is relatively sparse and irregular, key points alone cannot effectively assist the overhead crane 4 to locate its own position. Therefore, it is necessary to evenly arrange landmark points on the straight track segment to assist the overhead crane 4 to locate its own position. Generally, the length of the curved track segment is short, so landmark points are not set. In fact, landmark points can also be set on the curved track segment according to actual needs.

The landmarks can be used to assist the overhead crane 4 in locating its own position, and the key points can be used to assist the overhead crane 4 in speed control, which is beneficial to ensuring the safe operation of the overhead crane 4 and accurately reaching the target loading and unloading position, and is beneficial to improving the overall transportation efficiency of the overhead crane group.

In some embodiments, the map information further includes a one-way graph structure, which is used to record the upstream and downstream relationships between the identification points 91. The one-way graph structure is used to limit each track segment to one-way travel, thereby avoiding blockage and collision caused by the overhead crane 4 traveling in opposite directions in the same track segment, and at the same time, it can simplify the transportation path planning process and improve planning efficiency.

Preferably, when the overhead crane 4 controls its own speed according to the map information and the overhead crane information, it executes:

If no transport mission is received, it will move along the preset patrol route and control its speed according to the map information and overhead crane information during the movement;

If a transport task is received, the vehicle will move along the corresponding transport route and control its speed according to map information and overhead crane information during the movement.

When no transport task is received, the overhead crane 4 is ordered to patrol according to a preset patrol path (which can be set according to actual needs) until a transport task is received and then switch to move according to the corresponding transport path, thereby effectively avoiding congestion caused by the overhead crane 4 without a task.

Specifically, as shown in FIG5 , the overhead crane 4 controls its own speed according to the map information and the overhead crane information during the movement, and specifically performs:

A1. Initialize the control mode of the overhead crane to the early warning mode;

A2. If the current control mode of the crane is the early warning mode, the speed of the crane is adjusted according to the type of key points detected, and the early warning distance is determined in real time according to the crane information to switch the control mode; the control modes include following mode, avoidance mode and early warning mode (it should be noted that the position control mode and speed control mode mentioned above are control modes for the travel servo motor, which can be called motor control mode, and the control mode here is the speed adjustment control mode for the crane 4, which can be called vehicle speed control mode for easy distinction);

A3. If the current control mode of the overhead crane is the following mode, the speed of the crane is adjusted according to the speed of the preceding vehicle to follow the preceding vehicle until the first preset condition is met, then the control mode of the overhead crane is switched to the warning mode and the process returns to step A2;

A4. If the current control mode of the overhead crane is the avoidance mode, the speed of the crane is adjusted according to the avoidance rule until the second preset condition is met, the control mode of the overhead crane is switched to the warning mode, and the process returns to step A2.

Among them, no matter whether the overhead crane 4 moves according to the patrol path or the transportation path, the control mode of the overhead crane 4 is first initialized to the early warning mode. In the early warning mode, the overhead crane 4 adjusts its own movement speed according to the type of key points detected, and determines the early warning distance in real time according to its own overhead crane information for control mode switching processing.

Further, as shown in FIG6 , in step A2, the movement speed of the self is adjusted according to the type of the detected key point, specifically including:

B1. Determine the key points related to the current driving path (patrol path or transport path) of the overhead crane as relevant key points;

B2. When the relevant key point is detected, determining the type of the relevant key point detected;

B3. If the detected relevant key point is a straight line point or a separation point, the target speed of the overhead crane is set to the maximum moving speed, and the acceleration of the overhead crane is set to the maximum acceleration;

B4. If the detected relevant key point is an early deceleration point, the target speed of the crane is set to the preset maximum turning speed, and the acceleration of the crane is set to the maximum deceleration (determined by the deceleration performance of the crane 4);

B5. If the detected relevant key point is a limit point, the speed of the overhead crane is set to be no higher than the maximum turning speed;

B6. If the detected relevant key point is a stop deceleration point, the target speed of the overhead crane is set to the preset minimum moving speed, and the acceleration of the overhead crane is set to the maximum deceleration;

B7. If the detected relevant key point is a positioning point, a precise positioning stop operation is performed to stop at the target loading and unloading position.

Among them, in step B1, for the patrol path, the relevant key points include all straight points, restriction points, separation points and early deceleration points in the patrol path; for the transportation path, the relevant key points include all straight points, restriction points, separation points and early deceleration points in the transportation path, and also include the positioning points and stop deceleration points corresponding to the target loading and unloading positions of the transportation path.

Wherein, step B2 includes: for each key point detected, determining whether the detected key point is a related key point, and if it is a related key point, determining the type of the detected related key point. Wherein, whether the detected key point is a related key point can be determined according to the identification position in the identification information of the key point (if the identification position of the detected key point is the same as the identification position of one of the related key points, then the detected key point is determined to be a related key point), or, the identification information also includes the identification point number, so as to determine whether the detected key point is a related key point according to the identification point number in the identification information of the key point (if the identification point number of the detected key point is the same as the identification point number of one of the related key points, then the detected key point is determined to be a related key point).

Among them, in step B3, the target speed of the overhead crane is set to the maximum moving speed, and the acceleration of the overhead crane is set to the maximum acceleration, so that the overhead crane accelerates at the maximum acceleration until the maximum moving speed is reached, other relevant key points are passed, or the control mode (referring to the vehicle speed control mode) is changed; if the maximum moving speed is accelerated, the maximum moving speed is maintained; if the relevant key points are passed before the maximum moving speed is accelerated, the speed is adjusted according to the other relevant key points; if the control mode (referring to the vehicle speed control mode) is changed before the maximum moving speed is accelerated, the speed is adjusted according to the changed control mode.

In step B4, the target speed of the overhead crane is set to the preset maximum turning speed, and the acceleration of the overhead crane is set to the maximum deceleration, so that the overhead crane decelerates at the maximum deceleration until the preset maximum turning speed is reached, thereby ensuring that the overhead crane enters the curved track section at the preset maximum turning speed.

Among them, in step B5, after the limit point is detected, the speed of the overhead crane can be set to the maximum turning speed or lower than the maximum turning speed. If it is set to lower than the maximum turning speed, it is necessary to slow down after passing the limit point.

Among them, in step B6, the target speed of the overhead crane is set to the preset minimum moving speed, and the acceleration of the overhead crane is set to the maximum deceleration, so that the overhead crane decelerates to the preset minimum moving speed at the maximum deceleration; wherein the minimum moving speed is a relatively small speed, which is specifically set according to the deceleration performance of the overhead crane 4 (which can be determined through experiments) to ensure that the overhead crane 4 can accurately stop at the target loading and unloading position when performing a precise positioning and stopping operation with the minimum moving speed as the initial speed after passing the positioning point.

Among them, in step B7, the precise positioning stop operation includes: switching the motor control mode of the crane to the position control mode, and performing position control on the travel servo motor of the crane, so that the crane continues to move for a preset parking distance and then stops. In this way, the high position control accuracy of the travel servo motor in the position control mode is utilized to ensure that the crane stops accurately at the target loading and unloading position.

Furthermore, in step A2, the warning distance is determined in real time according to the overhead crane information thereof, specifically including:

Calculate the warning distance based on the speed in the crane's own information.

For example, in some implementations, the warning distance may be calculated according to the following formula:

(1);

in, For the warning distance, is the speed in the crane information, is the distribution spacing of landmark points, is the boundary speed, is the maximum speed.

in, Requirements:

;

;

is the maximum braking distance, is the length of the overhead travelling crane, is the maximum deceleration; Preferably equal to , thereby meeting the safety requirements and avoiding the situation where the road signs are too sparse, resulting in the failure of each overhead crane 4 to upload the overhead crane information in a timely manner, thereby affecting the safety of the coordinated control between the overhead cranes 4.

in, Requirements:

;

As the dividing time; , and Substituting into the above formula, we can get and .

According to the above conditions, at twice The distance is enough for the overhead crane 4 to slow down from the maximum speed to a stop. The distance is enough for the 4-meter overhead travelling crane to decelerates to a stop, therefore, the warning distance determined according to formula (1) is sufficient to ensure the operation safety of the overhead crane 4.

Furthermore, in step A2, the process of controlling the mode switching includes:

According to the map information and the position in the own overhead crane information (i.e. the position of the own overhead crane), it is determined whether there is a junction within the warning distance in front of the own overhead crane;

If there is no junction within the warning distance in front of the crane and there are other cranes within the warning distance in front of the crane, the control mode of the crane is switched to the following mode;

If there is no junction within the warning distance in front of the overhead crane and there is no other overhead crane within the warning distance in front of the overhead crane, the control mode of the overhead crane is maintained in the warning mode;

If there is a junction within the warning distance in front of the overhead crane, the overhead crane does not need to pass through the curved track section when passing through the junction, and there are other overhead cranes within the warning distance in front of the overhead crane, the control mode of the overhead crane is switched to the following mode;

If there is a junction within the warning distance in front of the overhead crane, the overhead crane does not need to pass through the curved track section when passing through the junction, and there is no other overhead crane within the warning distance in front of the overhead crane, the control mode of the overhead crane is maintained in the warning mode;

If there is a junction within the warning distance in front of the overhead crane, the overhead crane needs to pass through a curved track section to pass the junction, and there are other overhead cranes between the overhead crane and the junction, the control mode of the overhead crane is switched to the following mode;

If there is a junction within the warning distance in front of the overhead crane, the overhead crane needs to pass through a curved track section to pass through the junction, there is no other overhead crane between the overhead crane and the junction, and there is another overhead crane within the reference warning distance behind the junction (i.e., the straight track section behind the junction, such as the arrow positions in the two cases on the left in Figure 3), the control mode of the overhead crane is switched to the avoidance mode;

If there is a junction within the warning distance in front of the overhead crane, the overhead crane needs to pass through a curved track section to pass through the junction, there are no other overhead cranes between the overhead crane and the junction, there are no other overhead cranes within the reference warning distance behind the straight road of the junction, and there are other overhead cranes within the reference warning distance in front of the straight road of the junction, then the control mode of the overhead crane is switched to the following mode;

If there is a junction within the warning distance in front of this overhead crane, this overhead crane needs to pass through a curved track section to pass through the junction, there are no other overhead cranes between this overhead crane and the junction, there are no other overhead cranes within the reference warning distance behind the straight road of the junction, and there are no other overhead cranes within the reference warning distance in front of the straight road of the junction, then the control mode of this overhead crane is maintained in the warning mode.

The junction is the intersection of the straight track section and the curved track section (as shown in Figure 3).

Preferably, the reference warning distance is the braking distance required for the overhead crane 4 to decelerate from the maximum moving speed to a stop at the maximum deceleration. When the overhead crane needs to pass through the curved track section to pass through the junction, it is impossible to know the real-time speed of the avoided overhead crane behind the straight road of the junction (only the speed uploaded by the avoided overhead crane each time it passes the marking point can be known). In order to ensure safety, it is reasonable to calculate the warning distance of the avoided overhead crane according to the maximum speed as the reference warning distance.

The process of the control mode switching process described above can be referred to FIG7. In the above manner, near the junction, the overhead crane 4 that needs to pass through the curved track section avoids the overhead crane 4 that does not need to pass through the curved track section (for example, in FIG3, the overhead crane 4 traveling in the arrow direction of the two situations on the left does not need to pass through the curved track section, and the overhead crane 4 traveling in the arrow direction of the two situations on the right needs to pass through the curved track section). Since the speed of the overhead crane 4 in the curved track section is usually lower than the speed in the straight track section, the overhead crane 4 that needs to pass through the curved track section avoids, which is easier to decelerate and avoid, thereby being safer, and the entire avoidance process is shorter (because the overhead crane 4 traveling in a straight line can pass through the junction faster), which has less impact on the overall transportation efficiency of the system.

Specifically, in step A3, the own moving speed is adjusted according to the speed of the front vehicle to achieve following the front vehicle, which specifically includes: obtaining the speed of the front vehicle in real time, and adjusting the own moving speed to be less than or equal to the speed of the front vehicle.

In some embodiments, the first preset condition is that the preceding vehicle is outside the warning distance in front of the present overhead travelling vehicle. That is, once the distance between the preceding vehicle and the present overhead travelling vehicle exceeds the warning distance in front of the present overhead travelling vehicle, the control mode of the present overhead travelling vehicle is switched to the warning mode.

In other embodiments, the first preset condition is: the duration of time that the preceding vehicle is outside the warning distance in front of the present overhead crane reaches a preset time threshold (which can be set according to actual needs). Sometimes, the speed of the preceding vehicle changes, causing the distance between the preceding vehicle and the present overhead crane to change near the warning distance in front of the present overhead crane, sometimes exceeding the warning distance, and sometimes becoming less than the warning distance. In order to avoid frequent switching of the control mode of the present overhead crane, the control mode of the present overhead crane is switched to the warning mode only when the duration of time that the preceding vehicle is outside the warning distance in front of the present overhead crane reaches the preset time threshold.

In other embodiments, the first preset condition is that the distance between the preceding vehicle and the overhead crane is not less than K times the warning distance in front of the overhead crane, where K is a proportional coefficient greater than 1. By setting a suitable K, frequent switching of the control mode of the overhead crane can also be avoided.

In some embodiments, in step A4, the avoidance rule includes: determining the avoidance speed according to the speed of the avoided overhead crane (i.e., the overhead crane 4 within the reference warning distance behind the straight road of the junction) obtained when the overhead crane enters the avoidance mode; decelerating the speed of the overhead crane to the avoidance speed at the maximum deceleration, maintaining the avoidance speed until the avoided overhead crane passes through the junction, and then accelerating or decelerating with the preset maximum turning speed as the target speed (if the avoidance speed is greater than the preset maximum turning speed, deceleration is performed, and if the avoidance speed is less than the preset maximum turning speed, acceleration is performed). Among them, a comparison table or conversion formula between the speed of the avoided overhead crane and the reference avoidance speed that can reliably ensure safety can be determined in advance through experiments. In actual applications, according to the actual speed of the avoided overhead crane, the corresponding reference avoidance speed is determined using the comparison table or conversion formula as the avoidance speed of the overhead crane.

Furthermore, if the overhead crane has entered the curved track section and the avoided overhead crane has not passed the junction, the overhead crane will be decelerated at the maximum deceleration. If it is decelerated to a stop, it will accelerate to pass the junction after the stop time reaches the preset stop time (which can be set according to actual needs). Sometimes, the avoided overhead crane may stop due to a fault when it is about to pass the junction. At this time, the overhead crane stops and waits for the preset stop time before accelerating to pass the junction, which can ensure safety while avoiding affecting the execution of the transportation task.

The second preset condition is that there is no other overhead crane within the reference warning distance behind the straight road of the merging entrance and there is no other overhead crane within the reference warning distance in front of the straight road of the merging entrance.

In summary, the overhead travelling crane control system provided by the present application has at least the following advantages:

1. It can adapt to the situation of a large number of cranes 4 and large-scale maps;

2. Using the track information acquisition processor 3 to detect the lost overhead crane and cooperating with the speed control strategy of the overhead crane 4 itself, the safety of the overhead crane 4 is ensured in a redundant secondary manner to reliably prevent collision;

3. The overhead crane 4 controls its own speed, so that even if the central dispatching server 1 makes a scheduling error, it can ensure that the overhead cranes 4 do not collide with each other;

4. Using the marking points to position the overhead crane 4 and control its stopping at the loading and unloading positions can ensure the parking positioning accuracy while reducing costs.

In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (10)

1. The crown block control system is characterized by comprising a central scheduling server, a map information database, a track information acquisition processor and a plurality of crown blocks arranged on a track, wherein the central scheduling server, the map information database, the track information acquisition processor and the crown blocks are in communication connection with each other; the track includes a plurality of track segments;

the central dispatching server is used for distributing transportation tasks to the crown blocks and planning transportation paths for the crown blocks;

the map information database is used for recording map information and crown block information of each crown block; the overhead travelling crane information comprises position and speed;

The track information acquisition processor is used for recording the in-out information of the crown block in-out each track section in real time according to photoelectric switches arranged at two ends of each track section, detecting whether the non-connected crown block exists in each track section according to the map information, the crown block information and the in-out information, and sending warning information to the map information database when the non-connected crown block exists in each track section, so that the map information database marks the corresponding track section, and the central scheduling server avoids the corresponding track section when planning a transportation path;

The overhead travelling crane is used for acquiring own overhead travelling crane information according to the identification points arranged on the track at intervals, uploading the acquired overhead travelling crane information to the map information database for updating the overhead travelling crane information, and controlling the speed of the overhead travelling crane according to the map information and the overhead travelling crane information.

2. The overhead traveling crane control system according to claim 1, wherein the overhead traveling crane performs, when acquiring the overhead traveling crane information of itself according to the identification points provided at intervals on the track:

And when each identification point passes, identifying the identification information of the identification point, extracting an identification position from the identification information to serve as the position in the crown block information of the crown block, and acquiring the speed of the crown block by a sensor to serve as the speed in the crown block information of the crown block.

3. The crown block control system of claim 1, wherein the identification points include waypoints and key points, the waypoints being equally spaced on each linear track segment, the key points including linear points, limit points, break-away points, anchor points, early deceleration points, and stop deceleration points;

the straight line points are used for prompting the downstream of the corresponding key points of the crown block to be a straight line track section which allows acceleration to the maximum speed;

The limiting points are used for prompting the positions of the corresponding key points of the crown block to be the starting points of the curve track sections;

the separation point is used for prompting the position of the corresponding key point of the crown block to be the termination point of the curve track section;

the positioning point is used for prompting the crown block to perform accurate positioning stopping operation so as to stop at the loading and unloading positions;

The advanced deceleration point is used for prompting that the crown block is about to enter a curve track section;

And the stopping and decelerating point is used for prompting that the crown block is about to reach a positioning point.

4. The crown block control system of claim 3, wherein the map information includes a one-way map structure for recording upstream and downstream relationships between the identified points.

5. The overhead traveling crane control system according to claim 3, wherein the overhead traveling crane performs, when performing speed control of itself based on the map information and the overhead traveling crane information:

If the transport task is not received, moving according to a preset patrol path, and controlling the speed of the vehicle according to the map information and the crown block information in the moving process;

If the transport task is received, the transport task moves according to the corresponding transport path, and the speed of the transport task is controlled according to the map information and the crown block information in the movement process.

6. The overhead travelling crane control system according to claim 5, wherein the overhead travelling crane controls its own speed according to the map information and the overhead travelling crane information during the movement, specifically performing:

A1. Initializing a control mode of the crown block into an early warning mode;

A2. if the current control mode of the crown block is an early warning mode, the motion speed of the crown block is regulated according to the type of the detected key point, and the early warning distance is determined in real time according to the crown block information of the crown block so as to perform control mode switching processing; the control mode comprises a following mode, an avoiding mode and an early warning mode;

A3. if the current control mode of the crown block is a following mode, the motion speed of the crown block is adjusted according to the speed of the front vehicle so as to realize the following of the front vehicle, and if the first preset condition is met, the control mode of the crown block is switched to an early warning mode and the step A2 is executed in a return mode;

A4. And if the current control mode of the crown block is an avoidance mode, adjusting the movement speed of the crown block according to an avoidance rule until a second preset condition is met, switching the control mode of the crown block into an early warning mode, and returning to the execution step A2.

7. The crown block control system according to claim 6, wherein in step A2, the movement speed of the crown block is adjusted according to the type of the detected key point, and specifically includes:

Determining key points related to the current running path of the crown block as related key points;

When the related key points are detected, determining the types of the detected related key points;

if the detected relevant key point is a straight line point or a separation point, setting the target speed of the crown block as the maximum moving speed and setting the acceleration of the crown block as the maximum acceleration;

if the detected relevant key point is an advanced deceleration point, setting the target speed of the crown block as a preset maximum turning speed, and setting the acceleration of the crown block as a maximum deceleration;

if the detected relevant key points are limiting points, setting the speed of the crown block to be not higher than the maximum turning speed;

If the detected relevant key point is a stopping deceleration point, setting the target speed of the crown block as a preset minimum moving speed, and setting the acceleration of the crown block as a maximum deceleration;

and if the detected relevant key point is a locating point, performing accurate locating stopping operation to stop at the target loading and unloading positions.

8. The crown block control system according to claim 6, wherein in step A2, the pre-warning distance is determined in real time according to the crown block information thereof, and specifically comprises:

And calculating the early warning distance according to the speed in the crown block information of the vehicle.

9. The crown block control system according to claim 6, wherein in step A2, the process of controlling the mode switching process includes:

judging whether a junction exists in the early warning distance in front of the own crown block according to the map information and the position in the crown block information of the own crown block;

If no junction is arranged in the early warning distance in front of the crown block and other crown blocks are arranged in the early warning distance in front of the crown block, switching a control mode of the crown block into a following mode;

if no junction is arranged in the early warning distance in front of the crown block and no other crown block is arranged in the early warning distance in front of the crown block, the control mode of the crown block is kept to be an early warning mode;

if a junction is arranged in the early warning distance in front of the crown block, the crown block passes through the junction without passing through a curve track section, and other crown blocks are arranged in the early warning distance in front of the crown block, switching a control mode of the crown block into a following mode;

If a junction is arranged in the early warning distance in front of the crown block, the crown block passes through the junction without passing through a curve track section, and no other crown block is arranged in the early warning distance in front of the crown block, the control mode of the crown block is kept to be an early warning mode;

If a junction is arranged in the early warning distance in front of the crown block, the crown block passes through the junction and needs to pass through a curve track section, and other crown blocks exist between the crown block and the junction, switching a control mode of the crown block into a following mode;

If a junction is arranged in the early warning distance in front of the crown block, the crown block passes through the junction and needs to pass through a curve track section, no other crown block exists between the crown block and the junction, and other crown blocks are arranged in the reference early warning distance behind a straight channel of the junction, the control mode of the crown block is switched to an avoidance mode;

if a junction port is arranged in the early warning distance in front of the crown block, the crown block passes through the junction port and needs to pass through a curve track section, no other crown block exists between the crown block and the junction port, no other crown block exists in the reference early warning distance behind the straight channel of the junction port, and the other crown block exists in the reference early warning distance in front of the straight channel of the junction port, switching a control mode of the crown block into a following mode;

If a junction port is arranged in the early warning distance in front of the crown block, the crown block passes through the junction port and needs to pass through a curve track section, no other crown block exists between the crown block and the junction port, no other crown block exists in the reference early warning distance behind the straight channel of the junction port, and no other crown block exists in the reference early warning distance in front of the straight channel of the junction port, the control mode of the crown block is kept to be an early warning mode.

10. The crown block control system of claim 9, wherein the reference warning distance is a braking distance required for the crown block to decelerate from a maximum travel speed to a stop at a maximum deceleration.