A method for avoiding traffic at intersections for AGV vehicles

Abstract

The present invention discloses a method for avoiding traffic at an intersection for an AGV, which relates to the field of AGVs, and mainly includes the steps of obtaining feedback signals during the movement of each AGV, and obtaining the road section information of each AGV according to the feedback signals; when the AGV enters the end of the waiting section from the passing section, when there is an AGV in the waiting section in front of the current AGV, the front and rear AGVs are controlled to maintain a preset distance according to the feedback signals; when the AGV enters the head end of the waiting section, when there is an AGV passing in the intersection section, the AGV is controlled to park at the head end of the waiting section, and when there is no AGV passing in the intersection section, the AGV in each waiting section is controlled to pass through the intersection section according to the intersection traffic sequence and the AGV priority level. The present invention sets different traffic rules in different sections through the setting of the passing section, the waiting section and the intersection section, so that the AGV can pass in an orderly manner when entering the intersection, avoiding collisions caused by disorderly passage, and the AGV can be regulated according to the importance of the transportation time through the setting of the priority.

Description

Technical Field

[0001] The invention relates to the field of AGV trolleys, and in particular to an intersection avoidance passage method for AGV trolleys. Background Art

[0002] AGV (Automated Guided Vehicles) is also known as unmanned transport vehicle, automatic navigation vehicle, laser navigation vehicle. Its notable feature is unmanned driving. AGV is equipped with an automatic guidance system, which can ensure that the system can automatically travel along the predetermined route without manual navigation, and automatically transport goods or materials from the starting point to the destination. Another feature of AGV is good flexibility, high degree of automation and high level of intelligence. The driving path of AGV can be flexibly changed according to the requirements of storage space, production process flow, etc., and the cost of changing the running path is very low compared with traditional conveyor belts and rigid transmission lines. AGV is generally equipped with a loading and unloading mechanism, which can automatically interface with other logistics equipment to realize the automation of the entire process of loading and unloading and handling of goods and materials. In addition, AGV also has the characteristics of clean production. AGV relies on its own battery to provide power. There is no noise and pollution during operation. It can be used in many places that require a clean working environment.

[0003] Based on the above advantages of AGV, in scenarios with high demand for logistics and transportation such as factory production, logistics and transportation are often carried out by automatic navigation logistics vehicles (AGVs), and as the demand for materials increases, the number of AGVs will increase. At some intersections where AGVs travel, due to the large volume of traffic, if there is no corresponding traffic avoidance method, it will cause congestion on the road section and even collision accidents with logistics vehicles, which can easily cause damage to the logistics vehicle itself and even cause the overturning of the materials carried. Therefore, in order to avoid such production accidents, improve the safety of transportation, and improve the overall traffic efficiency of logistics vehicles, a traffic avoidance method for intersections is needed to control the traffic of AGVs at intersections. Summary of the invention

[0004] In order to solve the problem of AGV passing through intersections in congested sections, the present invention proposes an intersection avoidance passage method for AGVs. The AGV driving section is divided into an intersection section, a passage section, and a waiting section between the intersection section and the passage section. The intersection section can only pass one AGV at a time. The method mainly includes the following steps:

[0005] S1: Obtain feedback signals from each AGV during its movement, and obtain the road section information of each AGV based on the feedback signals;

[0006] S2: When the AGV enters the end of the waiting section from the passing section, it is determined whether there is an AGV in the waiting section in front of the current AGV. If so, the front and rear AGVs are controlled to maintain a preset distance according to the feedback signal. If not, it goes to step S3;

[0007] S3: Determine whether there is an AGV passing through the intersection section. If so, control the AGV to park at the head end of the waiting section. If not, control the AGVs in each waiting section to pass through the intersection section according to the intersection passage sequence and AGV priority.

[0008] Furthermore, the intersection section is connected to a plurality of waiting sections.

[0009] Furthermore, in the step S2, if there is an AGV in the waiting section in front of the current AGV, the step S2 further includes:

[0010] Set the head obstacle avoidance sensor of the current AGV and the tail obstacle avoidance sensor of the preceding AGV to the shielded state.

[0011] Furthermore, in the step S2, if the AGV in the waiting section exceeds the preset warning value, the step further includes:

[0012] S21: converting the passing section connected to the end of the waiting section into a section of a preset length as the waiting section.

[0013] Furthermore, when the number of AGVs in the waiting section is lower than the preset control value, the method further includes the following steps:

[0014] S23: Control the length of the waiting segment to return to the initial length.

[0015] Furthermore, the AGV priority level includes a first priority level, a second priority level and a third priority level, and the initial state of the AGV is the third priority level. When the number of AGVs in the waiting section is higher than a preset warning value, the method further includes the following steps:

[0016] S22: Adjust the AGV priority level of the AGV at the head end of the waiting section to the second priority level.

[0017] Furthermore, if the current AGV is at the third priority level, the AGVs in the waiting segment ahead of the current AGV are in a passable state, and the AGVs in other waiting segments are in a waiting communication state.

[0018] Furthermore, in step S3, determining the order in which the AGV passes through the intersection section specifically includes the following steps:

[0019] S31: Determine whether the AGV priority levels of the AGVs at the head end of each waiting section are the same. If so, control the AGVs to pass through the intersection section in sequence according to the intersection traffic order. If not, control the high-priority AGV to pass through the intersection section according to the AGV priority level, and control the AGVs with the same AGV priority level to pass through the intersection section in sequence according to the intersection traffic order.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] (1) The intersection avoidance method for an AGV described in the present invention sets different traffic rules in different sections by setting a passing section, a waiting section and an intersection section, so that the AGV can pass through the intersection in an orderly manner and avoid collisions caused by disorderly passage;

[0022] (2) By setting the second priority, the system can selectively increase the transportation speed of a certain material according to the priority of the material. At the same time, by setting the first priority, a certain material can be quickly transported to the destination in an unobstructed manner in an emergency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A method step diagram for an intersection avoidance method for an AGV vehicle;

[0024] Figure 2 It is a schematic diagram of road section classification;

[0025] Figure 3 The system structure diagram of an intersection avoidance system for AGV vehicles. DETAILED DESCRIPTION

[0026] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0027] Embodiment 1

[0028] In order to solve the problem of traffic congestion and collision at intersections caused by increased traffic flow in actual application scenarios of AGV cars, such as Figure 1 As shown, the present invention proposes a method for avoiding passage at an intersection for an AGV, wherein the driving section of the AGV is divided into an intersection section, a passage section, and a waiting section between the intersection section and the passage section. The intersection section can only allow one AGV to pass at a time, and the method mainly includes the following steps:

[0029] S1: Obtain feedback signals from each AGV during its movement, and obtain the road section information of each AGV based on the feedback signals;

[0030] S2: When the AGV enters the end of the waiting section from the passing section, it is determined whether there is an AGV in the waiting section in front of the current AGV. If so, the front and rear AGVs are controlled to maintain a preset distance according to the feedback signal. If not, it goes to step S3;

[0031] S3: Determine whether there is an AGV passing through the intersection section. If so, control the AGV to park at the head end of the waiting section. If not, control the AGVs in each waiting section to pass through the intersection section according to the intersection passage sequence and AGV priority.

[0032] Here, if Figure 2 As shown, the present invention first divides the road section that the AGV trolley is to travel into three types, namely, the passing section, the waiting section and the intersection section. Among them, the end where the waiting section is connected to the passing section is defined as the end, and the end where the waiting section is connected to the intersection section is defined as the head end. It should be noted that the intersection section mentioned here refers to those intersections with three or more branches. In the conception of the present invention, the AGV in the passing section will not be controlled, and the AGV trolley will travel according to its own navigation. When the AGV trolley enters the waiting section, in order to ensure the orderly control of the passage of AGV vehicles in the intersection section, and only one AGV trolley passes through the intersection each time, it is necessary to intervene in the control in time when the AGV trolley enters the waiting section. Because the vehicle control is based on the status information of the AGV trolley, the present invention will obtain the feedback signal of the AGV trolley in real time during the driving process of the AGV trolley, and obtain the position information of the trolley and the AGV priority information according to the feedback signal.

[0033] It should be noted that in the actual operation process, the AGV car has a variety of road conditions after entering the waiting section, and there are different vehicle control problems under different road conditions. Therefore, the present invention designs control logic for the problems under different road conditions so that the AGV car can pass through the intersection more orderly and safely.

[0034] In the case where there is no congestion in the waiting section, in order to avoid the occurrence of collisions caused by the AGV car due to excessive speed, the method of the present invention will first determine whether there are other AGV cars in the waiting section. In the case of other vehicles, the AGV car is controlled to maintain a preset distance with the front car in both dynamic (the front AGV car is in motion) and static (the front AGV car is in parking) conditions to avoid collisions caused by too close distance. At the same time, since the AGV car is equipped with an obstacle avoidance sensor to avoid collisions during driving, if the preset distance (generally, in order to identify obstacles in time and avoid collisions, the warning distance is generally greater than the preset distance) is less than the warning distance of the obstacle avoidance sensor, the relative motion between the AGV cars will be locked, and the AGV car will enter a stopped state. In order to avoid the occurrence of this situation, in step S2, if there is an AGV in the waiting section in front of the current AGV, it also includes the step of setting the head obstacle avoidance sensor of the current AGV and the tail obstacle avoidance sensor of the front AGV to a shielded state.

[0035] When congestion occurs in the waiting section, that is, the AGVs in the waiting section are full and cannot accommodate more AGVs waiting to pass, in order to avoid collision between subsequent vehicles and the AGVs already in the waiting section, the present invention further includes the following steps in this state:

[0036] S21: converting the passing section connected to the end of the waiting section into a section of a preset length as the waiting section.

[0037] At the same time, if the number of AGVs in the waiting section gradually decreases and drops to a preset control value, in order to avoid the overall running speed of the AGVs being reduced due to the waiting section process, the following steps are also included:

[0038] S23: Control the length of the waiting segment to return to the initial length.

[0039] Furthermore, when the AGV is traveling in the waiting section, when the AGV reaches the head end of the waiting section and is about to enter the intersection section, if there are also AGVs at the head end of the waiting sections of other branches, it is inevitable that not every AGV can enter the intersection section. In order to ensure that the AGV can pass through the intersection in an orderly manner, the present invention also proposes setting priority levels so that the AGV can achieve orderly passage through the intersection in a certain order. Among them, the AGV priority levels include the first priority level, the second priority level and the third priority level. In the initial state, the AGV is usually at the third priority level.

[0040] According to the priority level of the AGV, in step S3 described above, the method for determining whether the AGV can pass through the intersection can be expressed as the following steps:

[0041] S31: Determine whether the AGV priority levels of the AGVs at the head end of each waiting section are the same. If so, control the AGVs to pass through the intersection section in sequence according to the intersection traffic order. If not, control the high-priority AGV to pass through the intersection section according to the AGV priority level, and control the AGVs with the same AGV priority level to pass through the intersection section in sequence according to the intersection traffic order.

[0042] Furthermore, in order to avoid material delivery timeout caused by too many AGVs staying in a waiting section, the present invention also proposes to use the priority system proposed above, and when the number of AGVs in the waiting section exceeds a preset warning value, set up steps:

[0043] S22: Adjust the AGV priority level of the AGV at the head end of the waiting section to the second priority level.

[0044] By raising the priority level of AGVs in congested sections, the section can quickly release congested AGVs to pass through the intersection, ensuring the overall traffic efficiency of the section.

[0045] At the same time, for some materials that need expedited delivery, the corresponding AGV can also be set to the first priority level. When an AGV of the first priority level appears in the road section, the AGV in the corresponding waiting section in front of the AGV is set to have priority through the intersection section, while the AGVs in other waiting sections connected to the intersection section are set to pass through the intersection section in turn according to the intersection traffic order and AGV priority level only after the AGV of the first priority level passes through the intersection section.

[0046] Furthermore, in a preferred embodiment, considering that the AGV carts used in the same workshop may not be of the same brand, there may be certain differences in the specific control methods. Therefore, if the current AGV cart needs to interact with equipment of other brands to complete driving on a certain path, such as interacting with AGV carts of other brands to pass through a certain intersection. It is possible to read the sensor signals of other brands to determine whether there are AGV carts of other brands passing through the intersection. For example, when the AGV cart of this brand is about to enter the intersection section, it sends an intersection entry request to AGV carts of other brands within a certain range. At this time, if the AGV cart of this brand can receive the feedback signal of the AGV cart of other brands, it will stop at the head end of the waiting section until it no longer receives the feedback signal of the AGV cart of other brands.

[0047] In summary, the intersection avoidance passage method for an AGV described in the present invention sets different passage rules in different sections through the setting of passage sections, waiting sections and intersection sections, so that the AGV can pass through the intersection in an orderly manner and avoid collisions caused by disorderly passage.

[0048] By setting the second priority, the system can selectively increase the transportation speed of a certain material according to the priority of the material. At the same time, by setting the first priority, a certain material can be quickly transported to the destination without hindrance in an emergency.

[0049] Embodiment 2

[0050] In order to better understand the technical content of the present invention, this embodiment describes the present invention in a system structure manner. Figure 3 As shown, an intersection avoidance passage system for AGV vehicles, the AGV vehicle driving section is divided into an intersection section, a passage section, and a waiting section between the intersection section and the passage section. The intersection section can only pass one AGV at a time. The system mainly includes:

[0051] The signal acquisition module is used to obtain the feedback signal of each AGV during its movement, and obtain the road section information of each AGV based on the feedback signal;

[0052] The waiting section control module is used to control the front and rear AGVs to maintain a preset distance according to the feedback signal when the AGV enters the end of the waiting section from the passing section and there is an AGV in the waiting section in front of the current AGV;

[0053] The intersection section control module is used to control the AGV to park at the head end of the waiting section when there is an AGV passing through the intersection section. When there is no AGV passing through the intersection section, the AGV in each waiting section is controlled to pass through the intersection section according to the intersection passage sequence and AGV priority.

[0054] Furthermore, the intersection section is connected with several waiting sections.

[0055] Furthermore, the waiting section control module also includes an excess warning unit, which is used to convert the passage section connected to the end of the waiting section into a section of preset length as the waiting section when the AGV in the waiting section exceeds a preset warning value.

[0056] Furthermore, the waiting section control module also includes a section recovery unit, which is used to control the length of the waiting section to return to the initial length when the number of AGVs in the waiting section is lower than a preset control value.

[0057] Furthermore, the AGV priority level includes a first priority level, a second priority level and a third priority level, and the initial state of the AGV is the third priority level.

[0058] Furthermore, the excess warning unit is further configured to adjust the AGV priority level of the AGV at the head end of the waiting section to the second priority level when the number of AGVs in the waiting section is higher than a preset warning value.

[0059] Furthermore, if the current AGV is at the third priority level, the AGVs in the waiting segment ahead of the current AGV are in a passable state, and the AGVs in other waiting segments are in a waiting communication state.

[0060] Furthermore, the intersection control module determines the order in which the AGV passes through the intersection as follows:

[0061] When the AGV priority levels of the AGVs at the head end of each waiting section are the same, the AGVs are controlled to pass through the intersection section in sequence according to the intersection traffic order; when they are different, the high-priority AGV is controlled to pass through the intersection section according to the AGV priority levels, and the AGVs with the same AGV priority levels are controlled to pass through the intersection section in sequence according to the intersection traffic order.

[0062] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0063] In addition, in the present invention, descriptions such as "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0064] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0065] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A method for avoiding traffic at an intersection for an AGV, characterized in that: The AGV driving section is divided into an intersection section, a passing section, and a waiting section between the intersection section and the passing section. The intersection section can only pass one AGV at a time, and mainly includes the following steps: S1: Obtain feedback signals from each AGV during its movement, and obtain the road section information of each AGV based on the feedback signals; S2: When the AGV enters the end of the waiting section from the passing section, it is determined whether there is an AGV in the waiting section in front of the current AGV. If so, the front and rear AGVs are controlled to maintain a preset distance according to the feedback signal. If not, it goes to step S3; S3: Determine whether there is an AGV passing through the intersection section. If so, control the AGV to park at the head end of the waiting section. If not, control the AGVs in each waiting section to pass through the intersection section according to the intersection passage order and AGV priority level; In the step S2, if the number of AGVs in the waiting section exceeds the preset warning value, the step further includes: S21: converting the passing section connected to the end of the waiting section into a section of a preset length as the waiting section; The AGV priority levels include the first priority level, the second priority level and the third priority level. The initial state of the AGV is the third priority level. When the number of AGVs in the waiting section exceeds the preset warning value, the following steps are also included: S22: Adjust the AGV priority level of the AGV at the head end of the waiting section to the second priority level.

2. A method for avoiding traffic at an intersection for an AGV as claimed in claim 1, characterized in that: The intersection section is connected with a plurality of waiting sections.

3. A method for avoiding traffic at an intersection for an AGV as claimed in claim 1, characterized in that: In the step S2, if there is an AGV in the waiting section in front of the current AGV, the step further includes: Set the head obstacle avoidance sensor of the current AGV and the tail obstacle avoidance sensor of the preceding AGV to the shielded state.

4. A method for avoiding traffic at an intersection for an AGV as claimed in claim 1, characterized in that: When the number of AGVs in the waiting section is lower than the preset warning value, the process further includes the following steps: S23: Control the length of the waiting segment to return to the initial length.

5. The method for avoiding traffic at an intersection for an AGV as claimed in claim 1, characterized in that: If the current AGV is of the third priority level, the AGVs in the waiting segment in front of the current AGV are in a passable state, and the AGVs in other waiting segments are in a waiting state for passing.

6. A method for avoiding traffic at an intersection for an AGV as claimed in claim 1, characterized in that: In step S3, the order of determining the AGV passing through the intersection section specifically includes the following steps: S31: Determine whether the AGV priority levels of the AGVs at the head end of each waiting section are the same. If so, control the AGVs to pass through the intersection section in sequence according to the intersection traffic order. If not, control the high-priority AGV to pass through the intersection section according to the AGV priority level, and control the AGVs with the same AGV priority level to pass through the intersection section in sequence according to the intersection traffic order.

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