Method for placing commercial vehicles in dense parking areas of transfer vehicles based on laser radar and GPS

Abstract

The present invention belongs to the technical field of commercial vehicle placement, and specifically relates to a method for placing commercial vehicles in dense parking areas for transfer vehicles based on laser radar and GPS. By recording the distance from the rear of the vehicle in front of the transfer AGV to the head of the vehicle it is clamping in advance when the rear of the front vehicle has not entered the interior of the AGV body, and then calculating the distance between the two commercial vehicles through GPS positioning, the problem of relying on the incomplete point cloud inside the transfer AGV to detect the distance from the rear of the vehicle in front to the head of the vehicle it is clamping is avoided, and the placement accuracy of the transfer AGV when performing the task of placing vehicles in dense parking areas is greatly improved. The method is easy to implement, has a stable effect, and has high accuracy, which fully guarantees the stable and efficient performance of the transfer AGV placing vehicles in dense parking areas, and has high value for promotion and application.

Description

Technical Field

[0001] The present invention belongs to the technical field of commercial vehicle placement, and in particular relates to a method for placing commercial vehicles in a transfer vehicle dense parking area based on laser radar and GPS. Background Art

[0002] At present, ports have achieved remarkable results in the automation construction of container and dry bulk terminals. The application of automation technology makes the loading and unloading of containers and dry bulk cargoes more efficient and accurate, and can reduce labor costs and improve the safety of the working environment. However, in roll-on / roll-off terminals, the transshipment of commercial vehicles still relies on traditional manual operations, which leads to a series of problems such as high labor costs, poor working environment, exhaust gas pollution, and safety hazards.

[0003] Therefore, it is imperative to solve the problem of automated transfer of commodity vehicle yards and accelerate the automated transformation and upgrading of commodity vehicle roll-on / roll-off terminals. By introducing automated technologies, such as automatic navigation systems, intelligent yard management systems, and automatic loading and unloading equipment, automated roll-on / roll-off operations of commodity vehicles can be realized, improving operational efficiency, reducing costs, and reducing personnel contact and safety risks.

[0004] In this context, the Automated Guided Vehicle (AGV) for commodity vehicle transfer came into being, bringing a new solution to automobile logistics. The working principle of the commodity vehicle transfer AGV is to achieve autonomous navigation and positioning of the vehicle through technologies such as laser navigation and satellite navigation. It can plan the path according to the transfer tasks in the actual operation, and autonomously shuttle in the roll-on / roll-off terminal to transport the commodity vehicle from the terminal to the designated parking location, or from the parking location to the terminal for loading and unloading operations.

[0005] In the operation process of commodity vehicle transfer AGV, achieving high-precision vehicle picking and placing is a challenging core problem. In order to avoid collision, scratches and damage to vehicles, this puts forward higher requirements on the positioning control method of the vehicle picking and placing process. The present invention mainly focuses on the positioning and control method of the vehicle placing process.

[0006] When it comes to vehicle parking at a roll-on / roll-off terminal, there are usually two methods: sparse parking and dense parking.

[0007] Sparse parking means parking vehicles according to parking spaces. The location of each parking space is known, and the vehicle can be directly placed in the designated parking space. Sparse parking leaves a certain distance between the parked vehicles. This parking method can provide better ventilation and working space, and facilitate vehicle entry and exit and operation. Therefore, this parking method has low control accuracy requirements and is not the main problem faced by the transfer AGV in placing vehicles.

[0008] Close parking means that the vehicle is not parked completely in the parking space, but parked a certain distance behind the front vehicle. The specific location should be determined by the parking situation of the front vehicle and the actual space size. This method usually causes the vehicles to be parked very closely, and the gaps between vehicles are compressed to a minimum, allowing more vehicles to be parked in a limited space. In the close parking scenario, the space for the transfer AGV to pass becomes very limited, which requires the AGV to have higher navigation accuracy. Therefore, close parking has become a major problem for the autonomous operation of the transfer AGV. Summary of the invention

[0009] In order to overcome the problems in the prior art, the present invention proposes a method for placing commercial vehicles in a dense parking area for transfer vehicles based on laser radar and GPS.

[0010] The technical solution of the present invention to solve the above technical problems is as follows:

[0011] A method for placing commercial vehicles in a transfer vehicle dense parking area based on laser radar and GPS. The commercial vehicle transfer AGV is equipped with a laser radar as a perception system at each of the four corners of the vehicle, and is equipped with a GPS positioning system to provide vehicle body posture information, including the following steps:

[0012] Step 1: The commercial vehicle transfer AGV moves to the rear of the commercial vehicle in front, and the distance between the two reaches the preset value. The commercial vehicle transfer AGV body faces the commercial vehicle in front, and officially enters the commercial vehicle transfer AGV dense parking area release task process; during this period, the point cloud collected by the laser radar is obtained, the point cloud around and inside the commercial vehicle transfer AGV body is constructed, and the commercial vehicle transfer AGV self-positioning is completed through GPS;

[0013] Step 2: After the laser radar recognizes the point cloud of the commercial vehicle in front, calculate the distance from the rear of the commercial vehicle in front to the head of the commercial vehicle transfer AGV, and use the laser radar to construct the internal point cloud of the commercial vehicle transfer AGV, calculate the distance from the head of the commercial vehicle clamped by the commercial vehicle transfer AGV to the head of the commercial vehicle transfer AGV, and add the two to get the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it clamps;

[0014] Step 3: Monitor the distance from the rear of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it is holding. When the distance is less than the preset value, the commodity vehicle transfer AGV decelerates. After the deceleration is completed, during the operation of the commodity vehicle transfer AGV, record the distance from the rear of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it is holding, and record the current position of the commodity vehicle transfer AGV through GPS;

[0015] Step 4: Obtain the current position of the commodity vehicle transfer AGV through GPS, calculate the distance traveled compared to the distance from the tail of the vehicle in front of the AGV to the head of the vehicle it is clamping recorded in step 3, subtract the traveled distance from the recorded distance, and obtain the distance from the tail of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it is clamping;

[0016] Step 5: Monitor the distance from the rear of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it is holding, set the speed limit for the transfer AGV according to the distance, gradually slow down, and stop at the specified release distance to complete the transfer AGV's task of releasing the vehicle in the dense parking area.

[0017] Furthermore, the preset value is 3m.

[0018] Furthermore, the laser radars are all multi-line laser radars.

[0019] Furthermore, in step three, the speed of the commodity vehicle transfer AGV is limited to 0.05 m / s, and after waiting for 2 seconds, it is considered that the deceleration is completed.

[0020] Furthermore, in the step five, if the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it clamps is more than 0.8m, the speed limit of the commercial vehicle transfer AGV is 0.4m / s; if the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it clamps is 0.8m-0.5m, the speed limit of the commercial vehicle transfer AGV is 0.2m / s; if the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it clamps is 0.5m-0.32m, the speed limit of the commercial vehicle transfer AGV is 0.05m / s; if the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it clamps is 0.32m, a stop command is issued.

[0021] Compared with the prior art, the present invention has the following technical effects:

[0022] (1) The present invention discloses a method for placing commercial vehicles in dense parking areas based on laser radar and GPS. The method records the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the vehicle it is clamping before the rear of the commercial vehicle in front has not entered the body of the commercial vehicle transfer AGV, and then calculates the distance between the two commercial vehicles through GPS positioning. This avoids the problem of relying on the incomplete point cloud inside the commercial vehicle transfer AGV to detect the distance from the rear of the commercial vehicle in front to the head of the commercial vehicle it is clamping, and greatly improves the placement accuracy of the commercial vehicle transfer AGV when performing the task of placing commercial vehicles in dense parking areas. The method is easy to implement, has stable effects and high accuracy, fully guarantees the stable and efficient performance of the commercial vehicle transfer AGV task of placing commercial vehicles in dense parking areas, and has high value for promotion and application.

[0023] (2) The present invention meets the demand for releasing vehicles in dense parking areas by leveraging the existing structural features of the straddling catamaran commercial vehicle transfer AGV and the sensor units that have been equipped. The method has a simple process and high operating efficiency and accuracy. It can be well applied to the operation of the commercial vehicle transfer AGV and fully meets the actual needs of the commercial vehicle transfer AGV to complete the task of releasing commercial vehicles in dense parking areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a flow chart of a method for placing commercial vehicles in a dense parking area for transfer vehicles based on laser radar and GPS proposed by the present invention;

[0026] Figure 2 It is a laser radar point cloud map of the transfer AGV of the present invention completing the task of releasing the vehicle in the dense parking area. DETAILED DESCRIPTION

[0027] In order to further explain the technical means and effects taken by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the technical solutions proposed by the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments. The specific features, structures or characteristics in one or more embodiments may be combined in any suitable form. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by technicians in the technical field of the present invention.

[0028] The purpose of the present invention is to provide a method for placing commercial vehicles in dense parking areas for transfer vehicles based on laser radar and GPS, which can safely and efficiently complete the parking task of commercial vehicles in dense parking areas when the space is small and the parking position needs further detection.

[0029] The method is based on a straddle-type double-body commercial vehicle transfer AGV, which is equipped with a laser radar as a perception system at each of the four corners of the vehicle, and is equipped with a GPS positioning system to provide vehicle body posture information. The GPS positioning system uses differential GPS with a resolution of 1 cm, that is, high-precision positioning technology is used on the basis of the GPS positioning system, such as real-time dynamic carrier phase differential technology (RTK-GPS) or post-processing technology. These technologies can significantly improve positioning accuracy by comparing data from multiple GPS receivers, reaching centimeter-level or even millimeter-level resolution; the straddle-type double-body commercial vehicle transfer AGV is arch-shaped in appearance. When transferring a commercial vehicle, the commercial vehicle transfer AGV "straddles" the commercial vehicle, wraps the commercial vehicle inside the "arch", and fixes the four tires of the commercial vehicle respectively through the four clamping devices installed inside, lifts the commercial vehicle, and drops the commercial vehicle after arriving at the designated location to complete the transfer process.

[0030] The laser radars installed on the four corners of the commercial vehicle transfer AGV are all multi-line laser radars, which can construct laser point clouds around and inside the vehicle body. However, due to the interference of the metal body on the laser radar signal and the occlusion of the vehicle body itself, the internal point cloud data is incomplete, which affects the accurate perception of the interior space and adjacent obstacles. In the dense parking area, vehicles are parked closely. When the commercial vehicle transfer AGV releases the vehicle in the dense parking area, the required parking position of the commercial vehicle is close to the commercial vehicle in front. At this time, the rear of the commercial vehicle in front often enters the interior of the commercial vehicle transfer AGV. At this time, the internal point cloud can only be relied on to complete the detection of the distance between the vehicle being transferred by the commercial vehicle transfer AGV and the vehicle in front. Using these incomplete point clouds will make the distance detection inaccurate, and the accuracy of releasing the vehicle is difficult to guarantee.

[0031] The present invention solves the problem of executing the task of placing a vehicle in a dense parking area by a straddling catamaran-type commercial vehicle transfer AGV. The dense parking area placement task can be abstracted as: providing the spatial position and orientation of a parked commercial vehicle, requiring the transfer AGV to park the clamped commercial vehicle directly behind the commercial vehicle, and ensuring that the distance between the two vehicles is a specified value.

[0032] The present invention discloses a method for placing commercial vehicles in a dense parking area of ​​an intelligent transfer vehicle based on advance relative positioning. In order to better illustrate the purpose and advantages of the present invention, the following is combined with Figure 1-Figure 2 The invention content is further explained. The task in this example is that the commodity vehicle transfer AGV parks the commodity vehicle it is holding just behind the commodity vehicle in front, and ensures that the distance between the two commodity vehicles is 0.3m. The specific implementation steps are as follows:

[0033] Step 1: The commercial vehicle transfer AGV moves to the rear of the commercial vehicle in front, and the distance between the two reaches the preset value. The commercial vehicle transfer AGV body is facing the commercial vehicle in front, and officially enters the commercial vehicle transfer AGV dense parking area release task process; during this period, the point cloud collected by the laser radar is obtained, the point cloud around and inside the commercial vehicle transfer AGV body is constructed, and the commercial vehicle transfer AGV itself is positioned through GPS.

[0034] Specifically, the commercial vehicle transfer AGV clamps the commercial vehicle, and the commercial vehicle transfer AGV moves to the target position, that is, more than 3m behind the commercial vehicle, and the commercial vehicle transfer AGV body is basically facing the target position, and officially enters the commercial vehicle transfer AGV dense parking area release task process.

[0035] During this period, the commercial vehicle transfer AGV will obtain the point cloud data collected by the multi-line laser radars installed at the four corners of the commercial vehicle transfer AGV body. In order to ensure that all point cloud data are in the same reference frame and facilitate subsequent processing and analysis, the point cloud data collected by the four laser radars will be unified into the Cartesian coordinate system of the vehicle body, and the point cloud data will be preprocessed. The preprocessing includes merging, filtering, etc. The merging is to merge the point cloud data from different laser radars into a complete three-dimensional point cloud map. The filtering is to remove noise points, smooth the point cloud surface, and improve the accuracy and reliability of the data. Commonly used filtering methods include Gaussian filtering, median filtering, bilateral filtering, etc. The preprocessed point cloud data is used to construct a three-dimensional model around and inside the commercial vehicle transfer AGV body. This process usually involves point cloud segmentation, clustering, surface reconstruction and other steps. By constructing a three-dimensional model, the commercial vehicle transfer AGV can more intuitively understand the relationship between itself and the surrounding environment.

[0036] Perform range filtering near the coordinates of the commercial vehicle in front of the known target position to detect the point cloud of the commercial vehicle in front. Range filtering is a spatial filtering method that filters point cloud data according to a set distance range. In this scenario, range filtering is used to extract point cloud data in the area where the front vehicle is located for subsequent analysis and processing; the point cloud data after range filtering is used to detect the front vehicle, which usually involves steps such as point cloud segmentation, feature extraction and recognition. By identifying the features of the commercial vehicle in front (such as shape, size, position, etc.), the commercial vehicle transfer AGV can determine the existence of the front vehicle.

[0037] At the same time, the commodity vehicle transfer AGV receives the GPS positioning signal of position and heading through the GPS receiver. In this embodiment, two GPS antennas are used for positioning at the same time, one for positioning and the other for orientation, so as to determine the position of the commodity vehicle transfer AGV itself.

[0038] Step 2: After the laser radar recognizes the point cloud of the commercial vehicle in front, calculate the distance from the rear of the commercial vehicle in front to the head of the commercial vehicle transfer AGV, and use the laser radar to construct the internal point cloud of the commercial vehicle transfer AGV, calculate the distance from the head of the commercial vehicle clamped by the commercial vehicle transfer AGV to the head of the commercial vehicle transfer AGV, and add the two to get the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it clamps.

[0039] Specifically, after the laser radar recognizes the point cloud of the commercial vehicle in front, the point closest to the commercial vehicle transfer AGV in the point cloud of the commercial vehicle in front is taken, and the distance from this point to the head of the commercial vehicle transfer AGV is calculated as the distance from the tail of the commercial vehicle to the head of the commercial vehicle transfer AGV. The internal point cloud of the commodity vehicle transfer AGV is constructed through the laser radar. The point closest to the head of the internal point cloud of the commodity vehicle transfer AGV is taken, and the distance from the point to the head is calculated as the distance from the head of the vehicle clamped by the commodity vehicle transfer AGV to the head of the commodity vehicle transfer AGV. Add the two together to get the distance from the rear of the vehicle in front of the commodity vehicle transfer AGV to the head of the vehicle it is clamping. .

[0040] Step 3: Monitor the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it is holding. When the distance is less than the preset value, the commercial vehicle transfer AGV decelerates. After deceleration, during the operation of the commercial vehicle transfer AGV, record the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it is holding, and record the current position of the commercial vehicle transfer AGV through GPS.

[0041] Monitor the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it is holding. When the distance is less than 3m, limit the speed of the commercial vehicle transfer AGV to 0.05m / s, and wait for 2s before decelerating. The movement of the commercial vehicle transfer AGV slows down, and the recognition, ranging, and positioning accuracy are improved accordingly. At this time, record the distance from the rear of the vehicle in front of the AGV to the head of the vehicle it is holding. The current location of the commodity vehicle transfer AGV is recorded through GPS. The standard GPS system mainly provides latitude and longitude coordinates and speed information.

[0042] Step 4: Obtain the current position of the commodity vehicle transfer AGV through GPS, calculate the distance traveled compared to the distance from the tail of the vehicle in front of the AGV to the head of the vehicle it is clamped recorded in step 3, subtract the traveled distance from the recorded distance, and obtain the distance from the tail of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it is clamped.

[0043] After the recording is completed, in order to prevent the rear of the commercial vehicle in front of the commercial vehicle transfer AGV from entering the interior of the commercial vehicle transfer AGV, the distance from the rear of the commercial vehicle in front to the head of the vehicle it is clamping must be obtained by analyzing the incomplete internal point cloud. After that, the calculation of the distance will no longer rely on the method provided in step 3. Instead, the current transfer AGV posture is obtained through GPS to calculate the current position compared to the record. Distance traveled , subtract the distance traveled from the recorded distance to get the distance from the tail of the vehicle in front of the current vehicle transfer AGV to the head of the vehicle it is holding Practice has shown that this method has significantly higher accuracy than the method in step 2 when the distance between two commercial vehicles is relatively close.

[0044] Step 5: Monitor the distance from the rear of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it is holding, set the speed limit for the transfer AGV according to the distance, gradually slow down, and stop at the specified release distance to complete the transfer AGV's task of releasing the vehicle in the dense parking area.

[0045] Monitor the distance from the rear of the vehicle in front of the commercial vehicle transfer AGV to the head of the vehicle it clamps obtained in step four, and set the speed limit of the commercial vehicle transfer AGV according to the distance classification. If the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it clamps is more than 0.8m, the speed limit of the commercial vehicle transfer AGV is 0.4m / s; if the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it clamps is 0.8m-0.5m, the speed limit of the commercial vehicle transfer AGV is 0.2m / s; if the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it clamps is 0.5m-0.32m, the speed limit of the commercial vehicle transfer AGV is 0.05m / s; if the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it clamps is 0.32m, a stop command is issued, and the parking can be completed more accurately at 0.3m, thereby completing the task of releasing the commercial vehicle transfer AGV in the dense parking area.

[0046] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A method for placing commercial vehicles in dense parking areas of transfer vehicles based on laser radar and GPS. The commercial vehicle transfer AGV is equipped with a laser radar as a perception system at each of the four corners of the vehicle, and is equipped with a GPS positioning system to provide vehicle body posture information, characterized in that: The following steps are involved: Step 1: When the commercial vehicle transfer AGV moves to the rear of the commercial vehicle in front and the distance between the two reaches the preset value, the commercial vehicle transfer AGV body faces the commercial vehicle in front and officially enters the commercial vehicle transfer AGV dense parking area release task process; during this period, the point cloud collected by the laser radar is obtained, the point cloud around and inside the commercial vehicle transfer AGV body is constructed, and the commercial vehicle transfer AGV self-positioning is completed through GPS; Step 2: After the laser radar recognizes the point cloud of the commercial vehicle in front, calculate the distance from the rear of the commercial vehicle in front to the head of the commercial vehicle transfer AGV, and use the laser radar to construct the internal point cloud of the commercial vehicle transfer AGV, calculate the distance from the head of the commercial vehicle clamped by the commercial vehicle transfer AGV to the head of the commercial vehicle transfer AGV, and add the two to get the distance from the rear of the commercial vehicle in front of the commercial vehicle transfer AGV to the head of the commercial vehicle it clamps; Step 3: Monitor the distance from the rear of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it is holding. When the distance is less than the preset value, the commodity vehicle transfer AGV decelerates. After the deceleration is completed, during the operation of the commodity vehicle transfer AGV, record the distance from the rear of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it is holding, and record the current position of the commodity vehicle transfer AGV through GPS; Step 4: Obtain the current position of the commodity vehicle transfer AGV through GPS, calculate the distance traveled compared to the current recording, subtract the distance traveled from the recorded distance, and obtain the distance from the rear of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it is holding; Step 5: Monitor the distance from the rear of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it is holding, set the speed limit for the transfer AGV according to the distance, gradually slow down, and stop at the specified release distance to complete the transfer AGV's task of releasing the vehicle in the dense parking area.

2. According to claim 1, a method for placing commercial vehicles in a dense parking area for transfer vehicles based on laser radar and GPS is characterized in that: The preset value is 3m.

3. The method for placing commercial vehicles in a dense parking area for transfer vehicles based on laser radar and GPS according to claim 1 is characterized in that: The laser radars are all multi-line laser radars.

4. A method for placing commercial vehicles in a dense parking area for transfer vehicles based on laser radar and GPS according to claim 1, characterized in that: In the step 3, the speed of the commodity vehicle transfer AGV is limited to 0.05m / s, and after waiting for 2s, the deceleration is considered to be completed.

5. The method for placing commercial vehicles in a dense parking area for transfer vehicles based on laser radar and GPS according to claim 1 is characterized in that: In the step five, the speed limit of the commodity vehicle transfer AGV is set in stages, including: if the distance from the rear of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it clamps is more than 0.8m, the speed limit of the commodity vehicle transfer AGV is 0.4m / s; if the distance from the rear of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it clamps is 0.8m-0.5m, the speed limit of the commodity vehicle transfer AGV is 0.2m / s; if the distance from the rear of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it clamps is 0.5m-0.32m, the speed limit of the commodity vehicle transfer AGV is 0.05m / s; if the distance from the rear of the commodity vehicle in front of the commodity vehicle transfer AGV to the head of the commodity vehicle it clamps is 0.32m, a stop command is issued.

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