TWI676875B - AGV control system and control method, AGV system - Google Patents

Abstract

The invention provides an AGV control system, a control method, and an AGV system. The control system controls the AGV running on the magnetic strip guide, and the magnetic strip guide is provided with at least one station; the control system includes a control unit, a magnetic navigation sensor, an RFID reader, an RFID tag, and a station magnetic strip; According to the running direction of the AGV, the RFID tag is set between the starting point of the AGV and the work station and a preset distance from the work station, and the magnetic strip of the work station is set within the preset range of the work station; the control unit and the magnetic navigation sensor Both the RFID reader and the RFID reader are installed on the AGV. Both the magnetic navigation sensor and the RFID reader are in communication with the control unit. The RFID reader is used to detect the tag information identifying the RFID tag. The magnetic navigation sensor is used to detect the identification tool. Bit magnetic stripe, the control unit locates the position of the AGV according to the station magnetic stripe, and controls the AGV to execute the control instruction in the tag information of the RFID tag at the station. The invention can perform precise and positioning control on the AGV, and improves the control accuracy.

Description

AGV control system and control method, AGV system

The present invention relates to the field of control of automatic guided vehicles, and in particular to an AGV control system and control method, and an AGV system.

As labor costs are getting higher and manual management is more complex, more and more manual operations are gradually replaced by automated machines. Automated Guided Vehicles (AGVs) are equipped with electromagnetic or optical automatic guidance devices , A transport vehicle capable of traveling along a prescribed guide path, with safety protection and various transfer functions, is a kind of transporter that does not require a driver in industrial applications.

The AGV mostly uses magnetic navigation to work. The operation process is as follows: a magnetic strip guide is laid on the AGV preset travel path, and the AGV will run along the set magnetic strip guide. In addition, there will be multiple stations on the magnetic strip guide, and the AGV will make corresponding action changes according to instructions at the set stations, such as AGV stop or turn.

A conventional AGV control method is disclosed in the conventional technology. The magnetic strip guide has multiple stations, and the AGV performs preset motion changes at the corresponding stations, such as stopping or turning. In this solution, multiple RFID tags are set in front of each station of the magnetic strip guide. The tag information includes the position coordinates of the RFID tag, the distance from the corresponding station, and the corresponding control instructions, such as the AGV parking instruction and AGV left turn instruction. , AGV U-turn instructions, etc. At the same time, an RFID reader is installed on the AGV to detect and receive information on the RFID tag. When the AGV is running close to the RFID, the RFID reader will detect the information on the RFID tag and pass it to the control unit of the AGV. The control unit according to the control instruction, the distance between the AGV and the corresponding station, and the current speed of the AGV, etc. The information adjusts the AGV so that when the AGV reaches the corresponding station, the corresponding action changes.

However, in the above solution, because the range of the RFID reader to read the tag is too large, it is not accurate in estimating the distance between the AGV and the corresponding station. At the same time, after reading the corresponding tag information, the AGV will then calculate the distance based on the distance. The speed of the AGV is adjusted to expect the AGV to reach the corresponding station. The entire adjustment process depends on the estimation of the control unit, and there will be calculation errors. Therefore, due to the above-mentioned distance error and calculation error, this solution cannot guarantee that the AGV can change the action at the corresponding station, and the control of the AGV is not accurate.

The purpose of the present invention is to provide an AGV control system, a control method, and an AGV system, which can accurately control the AGV, so as to overcome the defect that the conventional technology cannot satisfy the AGV operation change at a corresponding station.

In order to solve the above technical problems, the present invention provides an AGV control system for controlling an AGV running on a magnetic strip guide, which is provided with at least one station; the control system includes a control unit and a magnetic navigation system. Sensors, RFID readers, RFID tags, and station magnetic stripe; according to the running direction of the AGV, the RFID tag is placed between the starting point of the AGV and the station and is pre-distanced from the station A distance is set, and the station magnetic strip is set within a preset range of the station; the control unit, the magnetic navigation sensor, and the RFID reader are all installed on the AGV, and the Both the magnetic navigation sensor and the RFID reader are communicatively connected with the control unit; the RFID reader is used to detect tag information identifying the RFID tag, and the magnetic navigation sensor is used to detect and identify the RFID tag. A workstation magnetic strip, the control unit accurately locates the position of the AGV according to the workstation magnetic strip, and controls the AGV to execute the control instruction in the tag information of the RFID tag at the workstation.

Further, the workstation magnetic strip is vertically attached to the magnetic strip guide rail to form a cross-shaped intersection with the magnetic strip guide for realizing the precise control of the AGV steering.

Further, the four wheels of the AGV are Mecanum wheels, and each Mecanum wheel is driven by an independent power unit provided on the AGV, and the control unit controls the four power units separately. Working status.

Further, along the running direction of the AGV, at least one magnetic navigation sensor is provided on the front and left and right sides of the AGV, and the magnetic navigation sensor in the front is used to detect and identify the magnetic stripe. The guide rails, the magnetic navigation sensors on the left and right sides are used to detect and identify the workstation magnetic stripe.

The present invention also provides a control method for controlling AGV by using the above-mentioned AGV control system, including the following steps: S1: The AGV travels along a magnetic strip guide, and an RFID reader detects tag information identifying the RFID tag. S2: When the RFID reader detects and recognizes the tag information, the control unit controls the magnetic navigation sensor to be turned on. S3: When the magnetic navigation sensor detects and recognizes a work station magnetic stripe, the control unit locates the position of the AGV according to the work station magnetic stripe, and controls the AGV to perform all operations at the work station. The control instructions in the tag information of the RFID tag are described.

Further, according to the traveling direction of the AGV, magnetic navigation sensors are provided on four sides of the AGV, one side of the AGV traveling direction is a front magnetic navigation sensor, and the other three sides correspond to the left side. The magnetic navigation sensor, the right magnetic navigation sensor, and the rear magnetic navigation sensor. In S1, the control unit controls the front magnetic navigation sensor to be turned on, and the magnetic navigation sensor detects and recognizes the location. The position of the magnetic strip guide is tracked to move the AGV along the magnetic strip guide shown; in S2, the control unit controls the left magnetic navigation sensor and / or the right magnetic navigation The sensor is turned on. In S3, the left magnetic navigation sensor and / or the right magnetic navigation sensor detect and identify the workstation magnetic stripe.

Further, in the step S3, the judgment condition that the magnetic navigation sensor detects and recognizes the magnetic stripe of the station is: ab≤ | d ₁ -d ₂ | ≤a + b, where | d ₁ -d ₂ | Is the distance between the center position of the station magnetic strip and the center position of the magnetic navigation sensor when the station magnetic strip is detected by the magnetic navigation sensor; a is a compensation value; b is a set error value, Wherein, a is obtained according to the current speed of the AGV and the distance between the AGV and the station, and b is obtained according to the detection accuracy and the sampling frequency of the magnetic navigation sensor.

Further, when the control instruction of the tag information is that the AGV is stopped, the S3 includes: when the left magnetic navigation sensor and / or the right magnetic navigation sensor detects and recognizes a work station magnetic strip, The control unit controls the AGV to be positioned at a work station and stops, and turns off the left magnetic navigation sensor and / or the right magnetic navigation sensor.

When the control instruction of the tag information is AGV traverse, forward or backward, the control method further includes S4: the control unit turns off the magnetic navigation other than the magnetic navigation sensor on the side where the AGV travel direction is located Sensor, and turn on the magnetic navigation sensor on the side where the AGV travel direction is located to track the magnetic strip guide, and the control unit controls the AGV to move laterally, forward or backward.

When the control instruction of the tag information is AGV steering, the control method further includes S4: the control unit turns off other magnetic navigation sensors except the front magnetic navigation sensor, and the front magnetic navigation sensor The magnetic strip guide is detected and identified to track the magnetic strip guide, and the control unit controls the AGV steering.

The invention also provides an AGV system, which includes an AGV and the above-mentioned AGV control system.

Compared with the conventional technology, the AGV control system provided by the present invention detects, recognizes and receives tag information through an RFID reader, and obtains control instructions at the workstation. At the same time, after detecting the tag information, the AGV will perform preprocessing. Including opening the magnetic navigation sensor to detect and identify the magnetic strip of the work station for accurate positioning, so that the AGV can accurately move to the work station to perform motion conversion, which improves the control accuracy.

At the same time, in the present invention, the AGV uses Mecanum wheels (or omnidirectional wheels, universal wheels) as wheels, and in cooperation with the above control system, it can accurately implement any movement change of the AGV at the station, including traverse, steering, and U-turn.

In addition, by optimizing the determination conditions of the magnetic stripe detected by the magnetic navigation sensor, the positioning of the AGV to the workstation is more accurate.

The AGV control method provided by the present invention has simple control operation and can accurately realize the positioning of the AGV at the work station and the change of the action of the AGV at the work station.

An AGV control system, a control method, and an AGV system provided by the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description and the scope of patent application. It should be noted that the drawings are in a very simplified form and all use inaccurate proportions, which are only used to facilitate and clearly assist the description of the embodiments of the present invention.

FIG. 1 is a schematic diagram of an AGV control system according to an embodiment of the present invention; FIG. 2 is a schematic structural diagram of AGV in an AGV control system according to an embodiment of the present invention; FIG. 3 is an AGV control provided by an embodiment of the present invention System architecture diagram of the system; FIG. 4 is a flowchart of an AGV control method according to an embodiment of the present invention; FIG. 5 is an AGV control method provided by an embodiment of the present invention to control the travel of four wheels when the AGV is advanced Directional diagram; FIG. 6 is a diagram illustrating the direction of travel of four wheels when the AGV is retracted in an AGV control method provided by an embodiment of the present invention; FIG. 7 is a diagram illustrating the control of AGV left in an AGV control method provided by an embodiment of the present invention FIG. 8 is a traveling direction diagram of four wheels during lateral movement; FIG. 8 is a traveling direction diagram of four wheels when controlling AGV right lateral movement in an AGV control method provided by an embodiment of the present invention; FIG. 9 is provided by an embodiment of the present invention An AGV control method is used to control the travel directions of four wheels when the AGV is turning left; FIG. 10 is an AGV control method according to an embodiment of the present invention to control the four wheels when the AGV is turning right. FIG. 11 is a diagram illustrating the direction of travel of four wheels when the AGV is rotated clockwise and the U-turn is controlled in an AGV control method according to an embodiment of the present invention; FIG. 12 is an AGV control method provided by an embodiment of the present invention The direction pattern of the four wheels when the middle control AGV is turned counterclockwise to the left.

Please refer to FIGS. 1 to 3. The present invention provides an AGV control system for controlling an AGV running on a magnetic stripe guide 10, which is provided with at least one station 20; the control system includes a control unit 60, magnetic navigation sensing Device 50, RFID reader 70, RFID tag 40, and station magnetic stripe 30. According to the running direction of the AGV, the RFID tag 40 is set between the starting point of the AGV and the station 20 and a preset distance from the station 20; the preset distance exists to give one end of the AGV Buffer distance, that is, when the AGV recognizes the information in the RFID tag 40, it will make corresponding pre-processing so that it can set up another station and perform corresponding action changes; the preset distance is determined by the speed of the AGV and the operation of the AGV. The vehicle condition is determined, and the RFID tag 40 may be disposed on the magnetic strip guide 10 or may be disposed on the side of the magnetic strip guide 10 as long as the RFID reader 70 of the AGV can The RFID tag 40 may be detected and recognized; preferably, the RFID tag 40 may be disposed on the magnetic strip guide 10. In this way, when the AGV is running on the magnetic strip guide 10, the range of the RFID tag 40 to be detected and recognized is wider, and it is easier to be captured by the RFID reader 70. The station magnetic stripe 30 is disposed within a preset range of the station 20. Specifically, the station magnetic stripe 30 may intersect with the magnetic strip guide rail 10, and the intersection point is at the station 20, and The included angle between the station magnetic stripe 30 and the magnetic stripe guide 10 may be 0-90 degrees. That is, the station magnetic strip 30 can be vertically attached to the magnetic strip guide 10 to form a cross-shaped intersection with it to facilitate the precise control of the AGV steering. In addition, the station magnetic strip 30 can also form a certain angle with the magnetic strip guide 10 . In addition, the station magnetic stripe 30 may also be arranged parallel to the magnetic stripe guide 10, that is, it does not intersect with the station 20, but is spaced a certain distance. The preset range distance is based on the magnetic navigation sense. Depending on the detection accuracy of the sensor 50, within this distance range, the AGV can detect the position magnetic stripe 30 and locate the position of the AGV, that is, in any form, as long as the magnetic navigation sensor 50 can detect and identify It is only necessary to reach the magnetic strip 30 of the station, and then to position the magnetic strip 30. The control unit 60, the magnetic navigation sensor 50, and the RFID reader 70 are all mounted on the AGV, and the magnetic navigation sensor 50 and the RFID reader 70 are all connected to the AGV. The control unit 60 is communicatively connected; among them, the control unit 60 can be a microcontroller, the RFID reader 70 is connected to the microcontroller using an RS232 interface, and the magnetic navigation sensor 50 can select its detection accuracy according to needs, for example, it can be 16 bits The magnetic navigation sensor 50 may be connected to a microcontroller using an RS485 interface; the RFID reader 70 is configured to detect and identify tag information of the RFID tag 40, and the tag information includes a control instruction, The control instruction is an action change instruction of the AGV at the station 20. In addition, the tag information also includes information such as the position coordinates of the RFID tag 40 and the distance between the RFID tag 40 and the station 20. The magnetic navigation sensor 50 is configured to detect and identify the station magnetic stripe 30. The control unit 60 accurately positions the AGV according to the station magnetic stripe 30 and controls the AGV at the station 20 And executing a control instruction in the RFID tag information. In the present invention, the RFID reader 70 detects and receives tag information to obtain control instructions at station 20. At the same time, after detecting the tag information, the AGV will perform preprocessing, including turning on the magnetic navigation sensor. 50 is used to detect and identify the station magnetic strip 30 in order to perform accurate positioning, so that the AGV can accurately move to the station 20 to perform motion conversion, thereby improving the control accuracy.

Please refer to FIG. 3. In the technical solution of this embodiment, the four wheels of the AGV are Mecanum wheels 80 (or universal wheels and omnidirectional wheels), and each Mecanum wheel 80 is provided by an independent setting. Driven by a power unit on the AGV, the control unit 60 controls the working states of the four power units, respectively; wherein each power unit may include an independent motor and a motor driver, and the motor driver is connected to the motor in one direction It is also connected to the control unit 60 at the same time. The control unit 60 controls the rotation of the motor through the motor driver. The rotation of the motor drives the Mecanum wheel 80 to move. By controlling the respective movement states of the four Mecanum wheels 80, the AGV can be advanced. Back, pan left and right, turn left and right, and turn around.

Preferably, along the running direction of the AGV, at least one of the magnetic navigation sensor 50 is provided on the front and left and right sides of the AGV, and the magnetic navigation sensor 50 on the front is used for detection and identification. The magnetic stripe guide 10, the magnetic navigation sensors 50 on the left and right sides are used to detect and identify the workstation magnetic stripe 30. More preferably, at least one of the magnetic navigation sensors 50 is provided on each of the four sides of the AGV. That is, at least one magnetic navigation sensor 50 is provided in the four directions of the front, rear, left, and right of the AGV. According to the direction of AGV travel, one side of the AGV travel direction is the front magnetic navigation sensor 50, and the other three sides correspond to The left magnetic navigation sensor 50, the right magnetic navigation sensor 50, and the rear magnetic navigation sensor 50. With four magnetic navigation sensors 50, one or more of the magnetic navigation sensors 50 can be turned on to detect and identify the magnetic stripe 30 of the work station.

The control method for controlling the AGV by using the AGV control system provided in this embodiment, as shown in FIG. 4, includes the following steps:

S1: AGV travels along the magnetic stripe guide 10, the control unit 60 controls the front magnetic navigation sensor 50 to open, and the magnetic navigation sensor 50 detects and identifies the position of the magnetic stripe guide 10 to track, To ensure that the AGV moves along the magnetic strip guide 10, the RFID reader 70 detects tag information identifying the RFID tag 40.

S2: When the RFID reader 70 detects and recognizes the tag information, the control unit 60 controls the magnetic navigation sensor 50 to be turned on, and when the AGV advances, the magnetic navigation sensor 50 on the side is turned on to work. The bit magnetic stripe 30 performs detection and identification, that is, the control unit 60 may control the left magnetic navigation sensor 50 and / or the right magnetic navigation sensor 50 to be turned on.

S3: When the magnetic navigation sensor 50 detects and recognizes the station magnetic stripe 30, the control unit 60 determines the position of the AGV according to the station magnetic stripe 30, and controls the AGV at the station. The control instruction in the tag information of the RFID tag 40 is executed at 20 places. It should be noted that the purpose of the side magnetic navigation sensor 50 in step S2 is mainly to detect and identify the station magnetic stripe 30. After the AGV is positioned at the station 20 in step S3, the control unit 60 controls the side The magnetic navigation sensor 50 is turned off. The front magnetic navigation sensor 50 has a tracking function, which is always turned on during the AGV's progress. If the magnetic strip guide 10 is not attached in the direction of travel, the car will generate an alarm and will not travel. When the AGV executes a control instruction at the station 20 to make an action change, the corresponding magnetic navigation sensor 50 is also turned on as needed.

Specifically, in step S3, the judgment condition that the magnetic navigation sensor 50 detects and recognizes the magnetic stripe 30 at the station is: ab≤ | d ₁ -d ₂ | ≤a + b. Where | d ₁ -d ₂ | is the position between the center position of the station magnetic strip 30 and the center position of the magnetic navigation sensor 50 when the station magnetic strip 30 is detected by the magnetic navigation sensor 50. Distance; a is the compensation value; b is the set error value. Wherein, a is obtained according to the current speed of the AGV and the distance between the AGV and the station 20, and b is obtained according to the detection accuracy and the sampling frequency of the magnetic navigation sensor 50.

In the above formula, | d ₁ -d ₂ | represents the distance between the center position of the workstation magnetic stripe 30 and the center position of the magnetic navigation sensor 50. When the magnetic navigation sensor 50 detects the station magnetic stripe 30, the width information of the station magnetic stripe 30 is projected onto the magnetic navigation sensor 50. For example, when the station magnetic stripe 30 has a width of 3 cm, The navigation sensor is 16-bit, and the detection and recognition range of 16 points with numbers 0-15 is 16cm. When the station magnetic strip 30 is exactly between the numbers 6-9, the center of the station magnetic strip 30 The position coincides with the center position of the magnetic navigation sensor 30. Since the side magnetic navigation sensor 50 is turned on when detecting the recognition station 20, generally, the side magnetic navigation sensor 50 is set at the AGV. The center position of the side, the center position of the side magnetic navigation sensor 50 and the center position of the AGV are on the same horizontal line, so the center position of the AGV will also be on the same horizontal line as the center position of the station magnetic strip 30 That is, the AGV is theoretically just moved to the station 20 at this time; when the station magnetic strip 30 is at another position, the center position of the AGV will be a distance from the center position of the magnetic navigation sensor 50, and the distance is | d ₁ -d ₂ |, when the distance value is 0, it means that the AGV has just moved to the position magnetic strip 30 at this time, that is, The AGV moves exactly to station 20.

a is the compensation value. Since the magnetic navigation sensor 50 detects the station magnetic strip 30 and the AGV reacts to the station 20, it takes a certain reaction time. If the center position of the station magnetic strip 30 and the magnetic After the center position of the navigation sensor 50 is completely coincident, the AGV responds again. At this time, the AGV needs a reaction time and a buffer distance from movement to stop. When the AGV is completely stopped, it will pass through the station 20, making the AGV unable. The operation changes at station 20 again, resulting in an error. Therefore, a certain buffer distance must be set, that is, the magnetic navigation sensor 50 must set a compensation value in the judgment condition of the magnetic stripe 30 of the work station. This compensation value is based on the current speed of the AGV in the actual application and the AGV. The distance from the station 20 is obtained.

b is a set error value. Due to the detection accuracy of the magnetic navigation sensor 50 and the limitation of the sampling frequency, the magnetic navigation sensor 50 will not perform the sampling detection identification station magnetic stripe 30 all the time. This will cause the magnetic navigation sensor 50 not to sample at a certain moment, but in fact, after adding the compensation value in the above formula, | d ₁ -d ₂ | is exactly equal to 0, that is, the best sampling point is missed. Therefore, a certain error value needs to be set. When | d ₁ -d ₂ | is within the tolerance range, all are counted as the magnetic navigation sensor 50 detects and recognizes the station magnetic stripe 30, and the AGV needs to perform corresponding processing to make The AGV is positioned on station 20. Taking a 16-bit magnetic navigation sensor 50 as an example, and its sampling frequency is 100 ms, the set error value b can be about 2 cm.

In the above technical solution, the accurate positioning of the AGV on the station 20 is achieved by the magnetic navigation sensor 50 on the side. In addition, when the AGV responds to the control command to make a change in the operation at the station 20, the same The magnetic navigation sensor 50 is turned on to assist the AGV to perform movement changes, so as to achieve the purpose of accurately controlling the AGV movement. The control instruction of the tag information may be AGV stop, AGV forward or backward, AGV lateral shift, AGV steering or U-turn, etc. Different control instructions need to turn on different magnetic navigation sensors 50 to assist AGV corresponding control Instruct to take action. The magnetic strip 30 at the station is perpendicular to the magnetic strip guide 10 as an example for description.

When the control instruction of the tag information is that the AGV is stopped, at this time, the steps S1-S3 described above are directly performed, so that the AGV is positioned at the station 20 and stopped, and the magnetic navigation sensor 50 on the side can be closed.

When the control instruction of the tag information is AGV traverse, in addition to performing the above steps S1-S3 to position the AGV to the station 20 and closing all the magnetic navigation sensors 50, the following step S4 needs to be performed: The control unit 60 controls the magnetic navigation sensor 50 on the side where the AGV traverse direction is located to track the magnetic strip guide 10, and the control unit 60 controls the AGV traverse; specifically, When panning to the left or to the right, the corresponding left or right magnetic navigation sensor 50 can be turned on. The magnetic navigation sensor 50 will instantly detect and identify the magnetic strip guide 10 for tracking to ensure the AGV's accurate horizontal movement. Mobile made. Wherein, the travel direction of each Mecanum wheel 80 during AGV traverse can be shown in FIG. 7 and FIG. 8 respectively.

When the control instruction of the tag information is forward or backward of the AGV, in addition to performing the above steps S1-S3 to position the AGV at the station 20, and closing the magnetic navigation sensor 50 except the side where the AGV travels, In addition to other magnetic navigation sensors 50, the following step S4 needs to be performed: the control unit 60 controls the magnetic navigation sensor 50 on the side where the AGV running direction is opened to perform the tracking of the magnetic strip guide 30, so The control unit 60 controls the AGV to advance or retreat. Specifically, when the AGV is moved forward or backward, the corresponding front or rear magnetic navigation sensor 50 may be turned on to track the magnetic strip guide 10 to ensure AGV. Precise forward and backward. Wherein, the traveling direction of each Mecanum wheel 80 when the AGV is moving forward or backward can be shown in FIG. 5 and FIG. 6 respectively.

When the control instruction of the tag information is an AGV steering, the AGV steering specifically includes a 90-degree turn of the AGV, a 90-degree turn of the right, a 180-degree turn of the U-turn, and an arbitrary degree of left-to-right steering. In addition to executing the above steps S1-S3 to position the AGV to the station 20 and closing other magnetic navigation sensors 50 except the front magnetic navigation sensor 50, the control method also needs to perform the following step S4: the control The unit 60 controls the front magnetic navigation sensor 50 to detect and identify the magnetic strip guide 10 to track the magnetic strip guide 10. The control unit 60 controls the AGV steering. When the AGV turns, its movement direction is always the head of the AGV first, so the front magnetic navigation sensor 50 will perform auxiliary monitoring at this time. For example, when turning 90 degrees left or 90 degrees right, the front magnetic navigation sense The detector 50 will detect the disappearance of the magnetic stripe guide 10 from the field of view, and then detect the magnetic stripe guide 10, that is, after the current magnetic navigation sensor 50 detects the above process, it indicates that the AGV has successfully turned to 90. degree. Similarly, when the U-turn is turned 180 degrees, the front magnetic navigation sensor 50 will detect the appearance of the magnetic strip guide 10 from the visual field to the disappearance, then to the appearance, to the disappearance and appearance. Wherein, when the AGV rotates, including the left turn, the right turn, the clockwise right turn and the counterclockwise left turn around, the travel directions of the Mecanum wheels 80 can be respectively shown in FIG. 9 to FIG. 12.

In addition, when the station magnetic stripe 30 is arranged parallel to the magnetic stripe guide 10 to achieve the positioning of the AGV at the station 20, the specific operation is as follows: as shown in FIG. 13, taking the AGV advancement as an example, when the AGV advancement detection When the RFID tag 40 is identified, the tag information in the RFID tag 40 includes information such as the position of the station magnetic stripe 30 and which side of the magnetic strip guide 30 the station magnetic stripe 30 is at. At this time, the control unit 60 controls The magnetic navigation sensor 50 on the AGV on the side where the magnetic stripe 30 is located is turned on, for example, using the AGV advancing direction as a reference. When the workstation magnetic stripe 30 is disposed on the right side of the magnetic stripe guide 10, the control unit 60 The right magnetic navigation sensor 50 is controlled to be turned on, and the right magnetic navigation sensor 50 detects and recognizes the magnetic strip 30 of the station to perform accurate positioning of the AGV. When the AGV retrogrades to the station magnetic strip 30 mentioned above, since the magnetic navigation sensor 50 on the side is not turned on, the operation of the AGV at this time is not affected by the station magnetic strip 30. That is, the AGV can turn on the corresponding magnetic navigation sensor 50 according to the tag information in the RFID tag 40 to identify the corresponding station magnetic stripe 30 in the tag information of the RFID tag 40 to achieve accurate control of the AGV, instead of relying solely on the station The magnetic stripe 30 controls the operation of the AGV, so that the AGV is not affected by the magnetic stripe 30 of the station when the AGV is in a non-set state such as AGV retrograde.

In another embodiment of the present invention, the magnetic stripe 30 of the station can also be two mutually perpendicularly disposed on one side of the magnetic stripe guide 10, that is, at this time, disposed on the side of the travel path of one magnetic stripe guide 10 A cross-shaped station magnetic stripe 30, for example, as shown in FIG. 14, according to the running direction of the AGV, a cross-shaped station magnetic stripe 30 is provided on the right side of the forward path of the magnetic strip guide 10. 30 can be used as a positioning control point for loading and unloading, so that the material can be moved up and down. At this time, the control unit 60 turns on the right magnetic navigation sensor 50 when detecting the tag information of the corresponding RFID tag 40, and the right side After the magnetic navigation sensor 50 detects the cross-shaped station magnetic strip 30, it will control the AGV to stop there and carry the material up and down, so that the fixed-point positioning control of the AGV is achieved.

The AGV control in the present invention is compared with the conventional technology that uses an RFID reader to identify an RFID tag and then locates a work station. The present invention is an experimental group and the conventional technology is a control group. Two methods are used to control the AGV. At this time, the deviation between the center position of the AGV and the center position of the station is shown in FIG. 15.

It can be seen that the use of the AGV control system and control method of the present invention to control the AGV is instantaneous, and the deviation fluctuation between the center position of the AGV and the center position of the station is much smaller than the conventional technology, indicating that the AVG using the present invention Compared with the conventional technology, the control accuracy and stability of the control system and control method when controlling the AGV have been greatly improved.

An embodiment of the present invention further provides an AGV system, including an AGV and the AGV control system described above.

The invention provides an AGV control system that detects and receives tag information through an RFID reader, and obtains control instructions at the workstation. At the same time, after detecting the tag information, the AGV performs preprocessing, including turning on magnetic navigation sensing. The device uses this to detect and recognize the magnetic strip of the work station for precise positioning, so that the AGV can accurately move to the work station to perform motion conversion, which improves the control accuracy.

At the same time, the AGV in the present invention uses Mecanum wheels as wheels and cooperates with the above control system to accurately realize any movement change of the AGV at the work station, including traverse, steering, and U-turn.

In addition, by optimizing the determination conditions of the magnetic stripe detected by the magnetic navigation sensor, the positioning of the AGV to the workstation is more accurate.

The AGV control method provided by the present invention has simple control operation and can accurately realize the positioning of the AGV at the work station and the change of the action of the AGV at the work station.

The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention. Any changes and modifications made by those of ordinary skill in the technical field to which the present invention pertains based on the above disclosure are protected by the scope of patent application range.

10‧‧‧ Magnetic strip guide

20‧‧‧Station

30‧‧‧Station magnetic stripe

40‧‧‧RFID tags

50‧‧‧ Magnetic Navigation Sensor

60‧‧‧Control unit

70‧‧‧RFID reader

80‧‧‧Mecanum Wheel

FIG. 1 is a schematic diagram of an AGV control system according to an embodiment of the present invention;

2 is a schematic structural diagram of an AGV in an AGV control system according to an embodiment of the present invention;

3 is a system architecture diagram of an AGV control system according to an embodiment of the present invention;

4 is a flowchart of an AGV control method according to an embodiment of the present invention;

FIG. 5 is a travel direction diagram of four wheels when controlling AGV forward in an AGV control method according to an embodiment of the present invention; FIG.

FIG. 6 is a diagram illustrating the traveling directions of four wheels when the AGV is controlled to retreat in an AGV control method according to an embodiment of the present invention;

FIG. 7 is a travel direction diagram of four wheels when the AGV is controlled to move leftward in an AGV control method according to an embodiment of the present invention;

8 is a travel direction diagram of four wheels when the AGV is controlled to move rightward in an AGV control method according to an embodiment of the present invention;

9 is a travel direction diagram of four wheels when the AGV is controlled to turn left in an AGV control method according to an embodiment of the present invention;

FIG. 10 is a travel direction diagram of four wheels when the AGV is controlled to turn right in an AGV control method according to an embodiment of the present invention;

FIG. 11 is a view of the traveling directions of the four wheels when the AGV is controlled to rotate clockwise to the right and U-turn in an AGV control method according to an embodiment of the present invention;

FIG. 12 is a diagram of the travel directions of the four wheels when the AGV is controlled to rotate counterclockwise to the left and turn around in an AGV control method according to an embodiment of the present invention;

13 is a schematic diagram of a magnetic stripe of a work station and a magnetic stripe guide rail in a method for controlling an AGV according to an embodiment of the present invention;

FIG. 14 is a schematic diagram when a station magnetic strip is cross-shaped on a side of a magnetic strip guide in an AGV control method according to an embodiment of the present invention; and

15 is a schematic diagram showing a deviation between the center position of the AGV and the center position of the work station when the AGV control system and method are provided by the embodiment of the present invention to control the AGV and the conventional technology is used to control the AGV.

Claims (10)

An AGV control system controls an AGV running on a magnetic strip guide. The magnetic strip guide is provided with at least one station. The AGV control system includes a control unit, a magnetic navigation sensor, An RFID reader, an RFID tag, and a station magnetic strip; according to the running direction of the AGV, the RFID tag is set between the starting point of the AGV and the station and a preset distance from the station, the The workstation magnetic strip is set in the preset range of the workstation; the control unit, the magnetic navigation sensor and the RFID reader are all installed on the AGV, the magnetic navigation sensor and the RFID reader Both are in communication connection with the control unit; the RFID reader is configured to detect and identify the tag information of the RFID tag, the magnetic navigation sensor is configured to detect and identify the station magnetic stripe, and the control unit is positioned according to the station magnetic stripe The position of the AGV and controls the AGV to execute the control instruction in the tag information of the RFID tag at the station. According to the AGV control system according to item 1 of the scope of the patent application, the magnetic strip of the station is vertically attached to the magnetic strip guide to form a cross-shaped intersection with the magnetic strip to realize the control of the AGV steering. The AGV control system according to item 1 of the scope of the patent application, wherein the four wheels of the AGV are a Mecanum wheel, and each Mecanum wheel is driven by an independent power unit disposed on the AGV. The control unit controls the working states of the four power units respectively. The AGV control system according to item 1 of the scope of the patent application, wherein, along the running direction of the AGV, at least one of the magnetic navigation sensor is provided on the front and left and right sides of the AGV, and the magnetic navigation sensor in the front is provided. The detector is configured to detect and identify the magnetic strip guide, and the magnetic navigation sensors on the left and right sides are configured to detect and identify the workstation magnetic strip. A control method for controlling an AGV by using the AGV control system according to any one of claims 1 to 4 of the scope of patent application, which includes the following steps: S1: the AGV travels along the magnetic strip guide, the RFID reader Detecting and identifying the tag information of the RFID tag; S2: when the RFID reader detects and recognizes the tag information, the control unit controls the magnetic navigation sensor to be turned on; S3: when the magnetic navigation sensor detects and recognizes the worker When the magnetic stripe is set, the control unit locates the position of the AGV according to the workstation magnetic stripe, and controls the AGV to execute the control instruction in the tag information of the RFID tag at the workstation. The control method according to item 5 of the scope of patent application, wherein in accordance with the direction of travel of the AGV, the magnetic navigation sensors are provided on the four sides of the AGV, and the side of the direction of the AGV is forward. For the magnetic navigation sensor, the other three sides correspond to the magnetic navigation sensor on the left, the magnetic navigation sensor on the right, and the magnetic navigation sensor on the rear. In S1, the control unit The front of the magnetic navigation sensor is controlled to be opened, and the magnetic navigation sensor detects and recognizes the position of the magnetic strip guide for tracking, for moving the AGV along the magnetic strip guide; in S2, the control unit controls The magnetic navigation sensor on the left and / or the magnetic navigation sensor on the right are turned on. In S3, the magnetic navigation sensor on the left and / or the magnetic navigation sensor on the right detect and identify the workstation. Magnetic stripe. The control method according to item 6 of the scope of patent application, wherein in S3, the determination condition that the magnetic navigation sensor detects and recognizes the magnetic strip of the station is: ab≤ | d ₁ -d ₂ | ≤a + b, where | d ₁ -d ₂ | is the distance between the center position of the station magnetic strip and the center position of the magnetic navigation sensor when the station magnetic stripe is detected by the magnetic navigation sensor ; A is a compensation value; b is a set error value, wherein a is obtained according to the current speed of the AGV and the distance between the AGV and the station, and b is obtained according to the detection accuracy and the sampling frequency of the magnetic navigation sensor. The control method according to item 6 of the scope of patent application, wherein when the control instruction of the tag information is the AGV traverse, forward or backward, the control method further includes S4: the control unit closes the The magnetic navigation sensor on one side other than the magnetic navigation sensor, and turning on the magnetic navigation sensor on the side where the AGV travelling direction is located, so as to track the magnetic strip guide, the control unit Controls the AGV's traverse, forward or backward. The control method according to item 6 of the scope of patent application, wherein when the control instruction of the tag information is the AGV steering, the control method further includes S4: the control unit turns off other than the magnetic navigation sensor in front In the magnetic navigation sensor, the magnetic navigation sensor in front detects and recognizes the magnetic strip guide to track the magnetic strip guide, and the control unit controls the AGV steering. An AGV system includes an AGV, and further includes an AGV control system according to any one of claims 1 to 4 of the scope of patent application.