CN214704001U

CN214704001U - Obstacle detection device for AGV

Info

Publication number: CN214704001U
Application number: CN202120114842.5U
Authority: CN
Inventors: 肖庆; 严凯辉; 董秀林; 陈晓利
Original assignee: Aerospace Intelligent Manufacturing Shanghai Technology Co ltd
Current assignee: Aerospace Intelligent Manufacturing Shanghai Technology Co ltd
Priority date: 2021-01-16
Filing date: 2021-01-16
Publication date: 2021-11-12
Anticipated expiration: 2031-01-16

Abstract

The utility model discloses a barrier detection device for AGV includes laser rangefinder module, PLC control module and audible-visual alarm module; the laser ranging module is connected with the PLC control module; the PLC control module is connected with the sound and light alarm module; the laser ranging module comprises three laser sensors, and the three laser sensors are all arranged on an object; three laser beams emitted by the three laser sensors are projected onto the surface of another object, and are respectively received by the three laser sensors after being reflected by the surface of the other object; the surface of the other object reflecting the three laser beams is a three-fold surface. The utility model discloses a barrier detection device for AGV solves forklift type AGV fork side barrier detection problem.

Description

Obstacle detection device for AGV

Technical Field

The utility model relates to a commodity circulation transportation, concretely relates to barrier detection device for AGV.

Background

Today, the application degree of the robot technology is becoming an important measurement factor for determining the mutual competition and future development among enterprises in the high-speed development of the traffic logistics industry. The automated guided vehicle AGV has been successfully used in the logistics industry as one of the intelligent robots, and its efficiency is self-evident. Especially, in the process of transporting and transferring goods, the AGV can be fully competent. In order to avoid the problem that the actual pallet deflection of the station and the scheduling terminal database are not matched due to manual misoperation or untimely inventory, the fork side must be provided with a barrier detection device in the loading and unloading process of the omnidirectional intelligent mobile forklift. For a forklift type AGV, obstacle detection on the fork side is generally applicable in three ways, and the advantages and disadvantages of the three ways are shown in table 1.

TABLE 1 advantages and disadvantages of three obstacle detection modes

The forklift type AGV has higher requirements on the precision for the loading and unloading of the goods, the laser ranging sensor has more implementation methods, and the goods at the detection station belong to short-distance displacement measurement, so a triangulation laser sensor is selected as the best.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a barrier detection device for AGV solves forklift type AGV fork side barrier detection problem.

In order to achieve the purpose, the utility model provides a barrier detection device for AGV, which comprises a laser ranging module, a PLC control module and an audible and visual alarm module; the laser ranging module is connected with the PLC control module; the PLC control module is connected with the sound and light alarm module; the laser ranging module comprises three laser sensors, and the three laser sensors are all arranged on an object; three laser beams emitted by the three laser sensors are projected onto the surface of another object, and are respectively received by the three laser sensors after being reflected by the surface of the other object; the surface of the other object reflecting the three laser beams is a three-fold surface.

Above-mentioned a barrier detection device for AGV, wherein, three laser sensor constitute an isosceles triangle, and a laser sensor equals to two other laser sensor's distance.

In the above obstacle detecting apparatus for an AGV, the surface of the other object that reflects the three laser beams is a high-reflectivity surface.

Above-mentioned obstacle detection device for AGV, wherein, the reflection of light material has been pasted on the surface that another object reflects three laser beam.

The obstacle detection device for the AGV, wherein the laser sensor includes a probe, an amplifier and a communication unit, the amplifier is connected to the probe, and the communication unit is connected to the multifunctional amplifier; the probe comprises two probes, one probe emits laser beams, and the other probe receives reflected laser beams.

The obstacle detection device for the AGV comprises three surfaces which are sequentially connected, wherein an included angle is formed between the two connected surfaces, and the value range of the included angle is 30-60 degrees.

The obstacle detection device for the AGV comprises three laser sensors, two laser sensors, a third laser sensor, an isosceles triangle and two laser sensors, wherein the three laser sensors are all arranged on a U-shaped fork; the other object is a tray.

Compared with the prior art, the beneficial technical effects of the utility model are that:

(1) high precision: the utility model discloses a barrier detection device for AGV adopts three laser sensor, and the plane of reflection of the barrier that is surveyed is established to three folding surfaces for can use triangulation to acquire relative position appearance between two objects, laser sensor has improved the goods precision of getting of omnidirectional movement fork truck, and omnidirectional intelligent movement equipment can be fast accurate action, has strengthened the robustness of system;

(2) high response speed: the distance and the state of the measured object can be rapidly displayed on the upper computer through a coordinate system and corresponding equivalent transformation, and a signal is transmitted to control the equipment to operate;

(3) economic and safe: laser sensor price is moderate, for the ultrasonic detection of expensive vision camera and low accuracy, the utility model discloses can improve high precision in limited cost range, guarantee the normal function of omnidirectional movement car.

Drawings

The present invention provides an obstacle detection device for AGVs, which is provided by the following embodiments and drawings.

Fig. 1 is a schematic diagram of an obstacle detecting device for AGVs according to a preferred embodiment of the present invention.

Fig. 2 is a schematic diagram of triangulation in a preferred embodiment of the present invention.

Detailed Description

The obstacle detecting device for AGVs according to the present invention will be described in further detail with reference to fig. 1 to 2.

The utility model discloses a barrier detection device for AGV includes laser rangefinder module, PLC control module and audible-visual alarm module; the laser ranging module is connected with the PLC control module and used for acquiring a measuring signal reflecting the relative pose between two objects and sending the measuring signal to the PLC control module; the PLC control module is connected with the sound-light alarm module, the PLC control module calculates the relative pose between two objects according to the measurement signal and judges whether the distance between the two objects is smaller than a set alarm distance threshold value, if so, the PLC control module sends an alarm instruction to the sound-light alarm module, and the sound-light alarm module sends out a sound-light alarm signal.

The present invention provides an obstacle detection device for AGVs.

In this embodiment, the obstacle detecting apparatus for an AGV is used to measure the relative position and attitude between a fork and a pallet.

In this embodiment, the laser distance measuring module includes three laser sensors, and three laser sensors are all installed on U type fork 10, wherein, two laser sensors are installed respectively at the foremost end of two fork strips 11 of U type fork 10, and the third laser sensor is located between these two laser sensors, and three laser sensor constitutes an isosceles triangle, and the distance from the third laser sensor to these two laser sensors equals.

Preferably, the laser sensor comprises a probe, a multifunctional amplifier and a communication unit, wherein the multifunctional amplifier is connected with the probe, and the communication unit is connected with the multifunctional amplifier; the probe is used as a device for transmitting and receiving laser beams, the multifunctional amplifier is used for signal conversion and amplification, and the communication unit is used for intelligent application expansion.

In this embodiment, in the loading and unloading process, the surface 21 of the pallet facing the pallet fork is a three-fold surface, that is, the surface 21 (i.e., the three-fold surface) includes three small surfaces connected in sequence, and an included angle is formed between the two connected small surfaces; the surface 21 (i.e., the triple-folded surface) should have a good reflectivity to the laser beam, and a reflective material may be attached to the surface 21 (i.e., the triple-folded surface) to increase the reflectivity of the surface.

The obstacle detection device for the AGV of the embodiment further comprises a PLC control module and an audible and visual alarm module; the laser sensor obtains a measuring signal reflecting the relative pose between the two objects, and sends the measuring signal to the PLC control module through the communication unit, and the PLC control module calculates the relative pose between the pallet fork and the pallet according to the measuring signal.

As shown in fig. 2, the surface of the pallet facing the fork is cut at a certain angle α, so that a three-fold surface is formed on the surface of the pallet facing the fork, and the value range of α is 30-60 °. ABCDFE in FIG. 2 represents a tray.

A laser sensor is respectively arranged at the foremost ends of the two fork strips of the fork, such as a T point and a Q point in figure 2; the mounting position of the third laser sensor is a U point, a T point and a Q point are connected, a perpendicular bisector of a line segment TQ is made, and the U point is located on the perpendicular bisector. KMNLQUT stands for pallet fork in fig. 2.

The middle point of the line section TQ is used as an original point to establish a two-dimensional coordinate, the straight line where the line section TQ is located is an X axis, the T point is in the negative direction of the X axis, the Y axis is perpendicular to the X axis, and the direction from the pallet fork to the pallet is the positive direction of the Y axis.

|TO|＝|OQ|＝l₄The three laser sensors can actually measure the absolute RT | ═ l₁、|SQ|＝l₂、|PU|＝l₃And the coordinate of the R point is (-l)₄，l₁) Coordinates of S (l)₄，l₂) Coordinate of P (0, l)₃) Coordinate of point T (-l)₄0), Q point coordinate (l)₄And 0), an intersection point o1 of the RQ and the ST, and solving the coordinate of the intersection point o1 to obtain the relative pose (distance and deflection angle theta) between the pallet fork and the pallet. In the case of a tray that is not deflected, intersection o1 should be on the Y axis (at the P point location), and if the tray is deflected, intersection o1 is offset from the Y axis.

k_RQ＝l₁/(-l₄-l₄)

k_ST＝l₂/(l₄+l₄)

Straight line L_RQ：

Straight line L_ST：

The coordinate of the intersection o1 is determined to be

I.e., the difference in coordinates of intersection o1 from ideal point p and the angle of theta determine the range direction and angle of the omni-directional vehicle.

1) Correcting position

The control cabinet is used as an upper computer, the omnibearing intelligent mobile equipment is used as a lower computer and an actuator, and the obstacle detection device is used as detection equipment.

The laser sensor emits laser beams at a certain fixed angle, when the laser beams meet an obstacle (a tray), the laser beams are refracted back at a certain angle and read by the laser sensor, a measurement signal acquired by the laser sensor is sent to the PLC control module, and the PLC control module calculates the relative position (distance and deflection angle theta) between the fork and the obstacle according to the triangular transformation, so that the position of the forklift is adjusted to reach the optimal state according to the relative position between the fork and the obstacle.

2) Fork side obstacle detection

The obstacle detection device for the AGV of the embodiment further comprises a sound and light alarm module, and the sound and light alarm module is connected with the PLC control module.

The sound-light alarm module sets two-stage judgment threshold values, when the obstacle is detected to be 0.3-2 m away from the TQ and is judged to be an actual obstacle, the PLC control module sends an alarm instruction to the sound-light alarm module, the sound-light alarm module sends out sound-light alarm, the PLC control module controls the forklift to stop running, and the current task can be continuously executed after the obstacle is removed; when the obstacle is detected within 0.3m, the situation that goods exist in the station is judged, the situation conflicts with the next execution action, so that the loading and unloading task of the next step is suspended, sound and light alarm is accompanied, and the vehicle can continue to work only by manually resetting after the situation is processed, so that the safe operation is ensured.

Claims

1. The obstacle detection device for the AGV is characterized by comprising a laser ranging module, a PLC control module and an acousto-optic alarm module; the laser ranging module is connected with the PLC control module; the PLC control module is connected with the sound and light alarm module;

the laser ranging module comprises three laser sensors, and the three laser sensors are all arranged on an object; three laser beams emitted by the three laser sensors are projected onto the surface of another object, and are respectively received by the three laser sensors after being reflected by the surface of the other object;

the surface of the other object reflecting the three laser beams is a three-fold surface.

2. The obstruction detection device for an AGV of claim 1, wherein three laser sensors form an isosceles triangle and one laser sensor is equidistant from the other two laser sensors.

3. The obstruction detection device for an AGV of claim 1, wherein the surface of the other object reflecting the three laser beams is a high reflectivity surface.

4. The obstruction detection device for an AGV of claim 1, wherein the other object has a reflective material adhered to a surface thereof reflecting the three laser beams.

5. The obstruction detection device for an AGV of claim 1, wherein said laser sensor includes a probe, a multifunction amplifier and a communication unit, said amplifier being connected to said probe, said communication unit being connected to said multifunction amplifier; the probe comprises two probes, one probe emits laser beams, and the other probe receives reflected laser beams.

6. The obstruction detection device for an AGV of claim 1, wherein said three-fold surface comprises three surfaces connected in series, and wherein the angle between the two connected surfaces is in the range of 30 ° to 60 °.

7. The obstruction detection device for an AGV of claim 1, wherein three laser sensors are mounted on the U-shaped fork, wherein two laser sensors are mounted at the foremost end of the two fork strips of the U-shaped fork, respectively, and a third laser sensor is located between the two laser sensors, the three laser sensors form an isosceles triangle, and the distance from the third laser sensor to the two laser sensors is equal; the other object is a tray.