AGV multi-level obstacle avoidance system and obstacle avoidance detection method

Abstract

The invention discloses an AGV multi-level obstacle avoidance system which comprises an AGV body and a fork part arranged at the front end of the AGV body, a sensor part and a control part in signal communication with the sensor part are arranged on the AGV body, and the control part is connected with a driver; the sensor part comprises a three-dimensional obstacle avoidance sensor located at the upper end of the AGV body, a front obstacle avoidance sensor located at the front end of the AGV body, a left obstacle avoidance sensor and a right obstacle avoidance sensor which are located on the two sides of the AGV body, and a safety edge contact sensor located on the outer edge of the AGV body, and the left obstacle avoidance sensor and the right obstacle avoidance sensor are located at the top of the AGV body; according to the invention, the 2D obstacle avoidance sensor RD1 and the 3D obstacle avoidance sensor RD2 are combined for use, small goods or obstacles scattered on the ground can be detected, the detection and obstacle avoidance capability of the AGV to small objects is effectively improved, and the obstacle avoidance detection precision of the AGV is improved.

Description

Technical Field

[0001] The present invention relates to the field of AGV vehicle safety technology, and in particular to an AGV multi-level obstacle avoidance system and an obstacle avoidance detection method. Background Art

[0002] At present, the intelligent logistics industry is developing rapidly. AGV, as an unmanned mobile robot, plays a very important role in the intelligent logistics industry. Especially in internal logistics scenarios such as warehousing, transshipment, and workshops, it is used more and more widely. Therefore, the consideration of AGV safety technology is an important indicator for measuring such products, and even a key factor in measuring a certain intelligent logistics project. For forklift-type AGVs with a large application volume, their conventional obstacle avoidance system is mainly composed of front 2D obstacle avoidance (including front two-corner 2D obstacle avoidance), fork tip reverse obstacle avoidance and safety touch edge, which can basically meet the application needs of general scenarios. However, in some scenarios, this obstacle avoidance system is more about detecting obstacles in a 2D plane area, and its application has certain limitations. Summary of the invention

[0003] The object of the present invention is to provide an AGV multi-level obstacle avoidance system and an obstacle avoidance detection method to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] An AGV multi-level obstacle avoidance system comprises an AGV body and a fork portion arranged at the front end of the AGV body, the AGV body is provided with a sensor portion and a control portion in signal communication with the sensor portion, and the control portion is connected to a driver;

[0006] The sensor unit includes a three-dimensional obstacle avoidance sensor located at the upper end of the AGV body, a front obstacle avoidance sensor located at the front end of the AGV body, a left obstacle avoidance sensor and a right obstacle avoidance sensor located on both sides of the AGV body, and a safety edge touch sensor located at the outer edge of the AGV body. The left obstacle avoidance sensor and the right obstacle avoidance sensor are located on the top of the AGV body.

[0007] As a further solution of the present invention: the horizontal field of view angle of the stereo obstacle avoidance sensor is L, and the vertical field of view angle is V. The horizontal field of view angle L ranges from 50° to 60°, and the vertical field of view angle V ranges from 90° to 360°.

[0008] As a further solution of the present invention: the scanning space area formed by the horizontal field of view angle L and the vertical field of view angle V of the three-dimensional obstacle avoidance sensor is larger than the width of the AGV body, and the maximum detection distance of the vertical field of view angle V of the three-dimensional obstacle avoidance sensor is larger than the braking distance of the AGV body.

[0009] As a further solution of the present invention: the left obstacle avoidance sensor and the right obstacle avoidance sensor are symmetrically arranged on the left and right sides of the AGV body, and the detection direction of the left obstacle avoidance sensor and the right obstacle avoidance sensor is up and down scanning detection, and the detection range of the left obstacle avoidance sensor and the right obstacle avoidance sensor does not exceed the connection between the AGV body and the fork part along the length direction of the AGV body.

[0010] As a further solution of the present invention: the three-dimensional obstacle avoidance sensor adopts a solid-state laser radar sensor.

[0011] As a further solution of the present invention: the front obstacle avoidance sensor is a plane obstacle avoidance sensor, and the front obstacle avoidance sensor is located at the lower part of the AGV body.

[0012] As a further solution of the present invention: the fork portion includes a fork body slidably connected to the AGV body up and down, two fork bodies are provided, and fork tip obstacle avoidance sensors are provided at the front ends of the two fork bodies, and the fork tip sensors are laser sensors.

[0013] An AGV obstacle avoidance detection method comprises the following steps:

[0014] Step 1: Get the AGV vehicle speed. If the AGV vehicle speed is greater than zero, execute step 2.

[0015] Step 2: Get the driving direction of the AGV. If the AGV is in the forward state, execute step 3; if the AGV is in the backward state, execute step 4.

[0016] Step 3: If any of the front obstacle avoidance sensor, the three-dimensional obstacle avoidance sensor, the left obstacle avoidance sensor, and the right obstacle avoidance sensor detects an obstacle or a pedestrian, the control unit controls the driver to slow down or stop running after receiving the detection information;

[0017] Step 4: When the fork tip obstacle avoidance sensor detects an obstacle or a pedestrian, the control unit controls the driver to slow down or stop running after receiving the detection information.

[0018] As a further solution of the present invention: in the step 2, it is simultaneously detected whether the safety edge sensor is triggered by a pedestrian or an obstacle. If the safety edge sensor is triggered, the control unit controls the AGV to brake urgently.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. This application combines the 2D obstacle avoidance sensor RD1 with the 3D obstacle avoidance sensor RD2 to detect smaller goods or obstacles scattered on the ground, effectively improving the AGV vehicle's ability to detect and avoid obstacles for smaller objects and improving the AGV's obstacle avoidance detection accuracy.

[0021] 2. Existing AGVs basically do not have the ability to detect obstacles falling from the air. This patent combines the 2D obstacle avoidance sensor RD1 with the 3D obstacle avoidance sensor RD2 to detect obstacles falling from the air, effectively improving the AGV's ability to detect obstacles falling from the air and improving the safety of AGV operation.

[0022] 3. The 3D obstacle avoidance sensor RD2 described in this patent is not limited by lighting conditions and field of view. It can perceive more complex scene environments in dim indoor and strong outdoor light environments. The horizontal field of view can be up to 360°, which improves the stability and application scope of AGV obstacle avoidance.

[0023] 4. Existing AGV vehicles do not detect pedestrians or obstacles well during turning, and cannot avoid obstacles efficiently during turning. This patent combines the 3D obstacle avoidance sensor RD2 with the side obstacle avoidance sensors RD3 and RD4, effectively solving the problem of unsatisfactory obstacle avoidance of AGV vehicles during turning, improving the obstacle avoidance effect of turning, and greatly improving the turning safety of AGV vehicles in a mixed human-machine operation environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a top view of the AGV of this embodiment;

[0025] Figure 2 This is the obstacle avoidance principle diagram of this embodiment;

[0026] Figure 3 Schematic diagram of the front 2D obstacle avoidance, fork tip reverse obstacle avoidance and side blind zone configuration for conventional AGV;

[0027] Figure 4 Schematic diagram of the front 2D obstacle avoidance and forward blind zone configured for conventional AGV;

[0028] Figure 5 Schematic diagram of the horizontal field of view and detection area of ​​3D obstacle avoidance in this embodiment;

[0029] Figure 6 Schematic diagram of the vertical field of view and detection area of ​​3D obstacle avoidance in this embodiment;

[0030] Figure 7 Schematic diagram of the detection area for side obstacle avoidance on both sides of this embodiment. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1-7 In an embodiment of the present invention, an AGV multi-level obstacle avoidance system includes an AGV body and a fork portion arranged at the front end of the AGV body, the AGV body is provided with a sensor portion and a control portion in signal communication with the sensor portion, and the control portion is connected to a driver;

[0033] The sensor part includes a three-dimensional obstacle avoidance sensor located at the upper end of the AGV body, a front obstacle avoidance sensor located at the front end of the AGV body, a left obstacle avoidance sensor and a right obstacle avoidance sensor located on both sides of the AGV body, and a safety edge touch sensor located at the outer edge of the AGV body. The three-dimensional obstacle avoidance sensor, the front obstacle avoidance sensor, the left obstacle avoidance sensor, and the right obstacle avoidance sensor are non-contact sensors, and the safety edge touch sensor is a contact sensor.

[0034] The front obstacle avoidance sensor, such as RD1 in the attached figure, is arranged at the front of the AGV vehicle using a front plane obstacle avoidance, and performs scanning and detection within a plane range at a certain height above the ground in front of the AGV vehicle. Its detection area is as follows Figure 3 As shown, the scanning range is set to a forward 180° area, and the detection area must be larger than the width of the AGV vehicle. When there are pedestrians or obstacles within a certain distance range scanned by RD1, the AGV vehicle slows down or stops running.

[0035] Stereo obstacle avoidance sensor, that is, Figure 1 The obstacle avoidance sensor RD2 in the stereo obstacle avoidance sensor adopts a solid-state laser radar sensor, which can perceive more complex scene environments in dim indoor and strong outdoor light environments. It has a larger field of view and more comprehensive point cloud data. It will not fail to detect due to lighting problems like airborne cameras. The horizontal field of view of the stereo obstacle avoidance sensor is L, and the vertical field of view is V. The horizontal field of view L ranges from 50° to 60°, and the vertical field of view V ranges from 90° to 360°. When the horizontal field of view L is set to 360°, full-circle stereo space range detection is performed. In this embodiment, the horizontal field of view can be set to 180° in combination with the customer's application scenario requirements. The detection range is as follows: Figure 5As shown in the figure, when a pedestrian or obstacle is detected within a certain space range scanned by RD2, the AGV vehicle will slow down or stop. The scanning space area formed by the horizontal field of view angle L and the vertical field of view angle V should be larger than the width of the AGV vehicle, and at the same time, the space area in front of the AGV vehicle should be covered as much as possible. The critical value of the vertical field of view angle V should be based on the critical value of the AGV vehicle body, so as to minimize the scanning blind area of ​​the 3D obstacle avoidance sensor RD2 in front of the AGV vehicle. The detection range is as follows: Figure 6 As shown, in the scanning space area formed by the horizontal field of view angle L and the vertical field of view angle V, the distance from the area where RD2 senses obstacle avoidance and deceleration to the AGV vehicle is greater than the braking distance of the AGV vehicle.

[0036] The left obstacle avoidance sensor and the right obstacle avoidance sensor, that is, RD3 and RD4 in the attached figure, are located on the top of the AGV body, and the left obstacle avoidance sensor and the right obstacle avoidance sensor are symmetrically arranged on the left and right sides of the AGV body, and the detection direction of the left obstacle avoidance sensor and the right obstacle avoidance sensor is up and down scanning detection, and the detection range of the left obstacle avoidance sensor and the right obstacle avoidance sensor does not exceed the connection between the AGV body and the fork part along the length direction of the AGV body. Some AGVs on the market use ultrasonic sensors as side obstacle avoidance functions, but the ultrasonic sensor has a small detection range and low detection accuracy, and cannot cover a large range from top to bottom on the side of the AGV vehicle, and it is difficult to effectively detect suspended obstacles on the side. The side obstacle avoidance sensors RD3 and RD4 of this embodiment can perform a large range of area detection from top to bottom on the side of the AGV vehicle, effectively solving the problem of obstacle avoidance detection of suspended obstacles on the side. At the same time, this type of side obstacle avoidance is more stable and more accurate than ultrasonic obstacle avoidance.

[0037] In this embodiment, the left obstacle avoidance sensor and the right obstacle avoidance sensor are scanned and detected from the top to the bottom on the side of the AGV vehicle. The scanning angle A can be set according to the needs of different scenarios. At the same time, the scanning area can be cut to meet the actual application needs of different projects. The detection range is as follows: Figure 7 As shown, when there are pedestrians or obstacles within the scanning range of the left obstacle avoidance sensor and the right obstacle avoidance sensor, the AGV vehicle slows down or stops.

[0038] The fork part includes a fork body that is slidably connected to the AGV body up and down. There are two fork bodies. The front ends of the two fork bodies are equipped with fork tip obstacle avoidance sensors. The fork tip sensors are laser sensors, namely LS1 and LS2 in the attached figure. Their main function is to be used for picking up and placing goods and linear stacking. They also serve as a reverse obstacle avoidance function when picking up and placing goods. When the fork is inserted into the pallet for picking up and placing goods, when the fork tip laser sensors LS1 and LS2 detect pedestrians or obstacles, the AGV vehicle slows down or stops running.

[0039] An AGV obstacle avoidance detection method comprises the following steps:

[0040] Step 1: Get the AGV vehicle speed. If the AGV vehicle speed is greater than zero, execute step 2.

[0041] Step 2: Get the driving direction of the AGV. If the AGV is in the forward state, execute step 3; if the AGV is in the backward state, execute step 4. At the same time, detect whether the safety edge sensor is triggered by pedestrians or obstacles. If the safety edge sensor is triggered, the control unit controls the AGV to brake urgently.

[0042] Step 3: If any of the front obstacle avoidance sensor, the three-dimensional obstacle avoidance sensor, the left obstacle avoidance sensor, and the right obstacle avoidance sensor detects an obstacle or a pedestrian, the control unit controls the driver to slow down or stop running after receiving the detection information;

[0043] Step 4: When the fork tip obstacle avoidance sensor detects an obstacle or a pedestrian, the control unit controls the driver to slow down or stop running after receiving the detection information.

[0044] By installing different types of obstacle avoidance sensors at different positions on the AGV vehicle, a multi-dimensional obstacle avoidance space combining the AGV vehicle's forward, reverse, left and right sides, and 3D stereo is constructed as the basis, and a multi-level obstacle avoidance system combining 2D plane and 3D stereo, side and forward, non-contact and contact is constructed. Its obstacle avoidance detection method is based on the detection principle of laser radar, and its configuration application and detection area on the AGV vehicle are cleverly designed to detect pedestrians and obstacles in the obstacle avoidance area, and the AGV vehicle is decelerated or stopped through the controller and driver.

[0045] This embodiment combines the front obstacle avoidance sensor RD1 with the three-dimensional obstacle avoidance sensor RD2, which has the function and advantage of effectively detecting smaller obstacles, greatly improving the accuracy of AGV obstacle avoidance detection. For example, in a certain implementation scenario, relatively small goods fall on the ground. When the front obstacle avoidance sensor RD1 does not detect the smaller goods, the three-dimensional obstacle avoidance sensor RD2 has a larger, more comprehensive and more accurate detection range, and can detect smaller goods, thereby causing the AGV vehicle to slow down or stop for obstacle avoidance. For example, in a certain implementation scenario, there is material transportation across the AGV operation channel, and occasionally some lighter goods will fall from the AGV channel. When the three-dimensional obstacle avoidance sensor RD2 detects that goods have fallen from the air, the AGV vehicle will take emergency braking, thereby avoiding or reducing the collision between the AGV vehicle and the goods, and minimizing damage or injury.

[0046] This embodiment combines the three-dimensional obstacle avoidance sensor RD2 with the side obstacle avoidance sensors RD3 and RD4, effectively expanding the detection space of the AGV vehicle during turning, improving the detection effect during turning, and improving the obstacle avoidance ability and safety of the AGV during turning. For example, in a certain implementation scenario, at the turning point of the AGV vehicle operation channel, there are often people passing by and manually driven forklifts carrying goods passing by, in an environment where people and machines are mixed. The detection range of the three-dimensional obstacle avoidance sensor RD2 in this embodiment is allowed to intersect with the detection range of the side obstacle avoidance sensors RD3 and RD4. The three-dimensional obstacle avoidance sensor is used in combination with the side obstacle avoidance sensors RD3 and RD4. The obstacle avoidance detection area of ​​the AGV vehicle during turning will be larger and more comprehensive, which improves the safety of people and goods during turning.

[0047] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0048] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An AGV multi-level obstacle avoidance system, comprising an AGV body and a fork portion arranged at the front end of the AGV body, characterized in that: The AGV body is provided with a sensor unit and a control unit which is in signal communication with the sensor unit, and the control unit is connected to a driver; The sensor unit includes a three-dimensional obstacle avoidance sensor located at the upper end of the AGV body, a front obstacle avoidance sensor located at the front end of the AGV body, a left obstacle avoidance sensor and a right obstacle avoidance sensor located on both sides of the AGV body, and a safety edge touch sensor located at the outer edge of the AGV body. The left obstacle avoidance sensor and the right obstacle avoidance sensor are located on the top of the AGV body.

2. The AGV multi-level obstacle avoidance system according to claim 1, characterized in that: The horizontal field of view angle of the stereo obstacle avoidance sensor is L, and the vertical field of view angle is V. The horizontal field of view angle L ranges from 50° to 60°, and the vertical field of view angle V ranges from 90° to 360°.

3. The AGV multi-level obstacle avoidance system according to claim 2, characterized in that: The scanning space area formed by the horizontal field of view angle L and the vertical field of view angle V of the three-dimensional obstacle avoidance sensor is larger than the width of the AGV body, and the maximum detection distance of the vertical field of view angle V of the three-dimensional obstacle avoidance sensor is larger than the braking distance of the AGV body.

4. The AGV multi-level obstacle avoidance system according to claim 1, characterized in that: The left obstacle avoidance sensor and the right obstacle avoidance sensor are symmetrically arranged on the left and right sides of the AGV body, and the detection direction of the left obstacle avoidance sensor and the right obstacle avoidance sensor is up and down scanning detection, and the detection range of the left obstacle avoidance sensor and the right obstacle avoidance sensor does not exceed the connection between the AGV body and the fork part along the length direction of the AGV body.

5. The AGV multi-level obstacle avoidance system according to claim 1, characterized in that: The three-dimensional obstacle avoidance sensor adopts a solid-state laser radar sensor.

6. The AGV multi-level obstacle avoidance system according to claim 1, characterized in that: The front obstacle avoidance sensor is a plane obstacle avoidance sensor, and the front obstacle avoidance sensor is located at the lower part of the AGV body.

7. The AGV multi-level obstacle avoidance system according to claim 1, characterized in that: The fork portion includes a fork body that is slidably connected to the AGV body up and down. Two fork bodies are provided. Fork tip obstacle avoidance sensors are provided at the front ends of the two fork bodies. The fork tip sensors are laser sensors.

8. An AGV obstacle avoidance detection method using an AGV multi-level obstacle avoidance system according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Get the AGV vehicle speed. If the AGV vehicle speed is greater than zero, execute step 2. Step 2: Get the driving direction of the AGV. If the AGV is in the forward state, execute step 3; if the AGV is in the backward state, execute step 4. Step 3: If any of the front obstacle avoidance sensor, the three-dimensional obstacle avoidance sensor, the left obstacle avoidance sensor, and the right obstacle avoidance sensor detects an obstacle or a pedestrian, the control unit controls the driver to slow down or stop running after receiving the detection information; Step 4: When the fork tip obstacle avoidance sensor detects an obstacle or a pedestrian, the control unit controls the driver to slow down or stop running after receiving the detection information.

9. The AGV obstacle avoidance detection method according to claim 8, characterized in that: In step 2, it is simultaneously detected whether the safety edge sensor is triggered by a pedestrian or an obstacle. If the safety edge sensor is triggered, the control unit controls the AGV to brake urgently.

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