Real-time position calculation method for four-way shuttle

Abstract

The present invention discloses a method for calculating the real-time position of a four-way shuttle. The method is implemented through a three-point positioning control system and includes the following steps: determining the current row position of the four-way shuttle within a shelf; setting a target row position for the four-way shuttle; calculating the row and column numerical difference between the current row and column position and the target row and column position; controlling the forward or reverse rotation of a travel motor based on the row and column numerical difference to drive the four-way shuttle; and a controller collecting signals from a positioning sensor and performing logical operations based on the rotation direction of the travel motor to calculate the position of the four-way shuttle. The present invention uses a dual calculation method to calculate the current position of the shuttle, ensuring the shuttle's accurate position. It also eliminates the need to attach a barcode or install an RFID chip, thus preventing the effects of barcode dust and RFID chip damage, thereby reducing costs.

Description

Technical Field

[0001] The present invention relates to the technical field of warehousing and logistics equipment, and in particular to a method for calculating the real-time position of a four-way shuttle vehicle. Background Art

[0002] In the existing technology, the real-time position calculation of four-way shuttle vehicles on the market is mainly achieved by reading RFID chips or barcodes, and the current position of the shuttle vehicle is obtained by reading the carrier information; warehouses generally have many cargo spaces, and if RFID chips or barcodes are used, brackets need to be made and chips need to be purchased, which will increase the overall cost significantly. Summary of the Invention

[0003] According to an embodiment of the present invention, a method for calculating the real-time position of a four-way shuttle is provided. The four-way shuttle travels within a shelf having a plurality of storage locations arranged in a matrix. The method is implemented using a three-point positioning control system, which includes a controller and two sets of positioning sensors. The controller is disposed on the four-way shuttle and is signal-connected to the two sets of positioning sensors and a travel motor for driving the four-way shuttle. Each set of positioning sensors includes three positioning sensors, one set of which is disposed on two opposite sides of the four-way shuttle, and another set of which is disposed on the remaining two sides of the four-way shuttle. The method includes the following steps:

[0004] Determine the current row and column position of the four-way shuttle within the rack;

[0005] Set the target row position of the four-way shuttle;

[0006] Calculate the difference between the current row and column position and the target row and column position;

[0007] According to the difference between the row and column values, the travel motor is controlled to rotate forward or reverse, driving the four-way shuttle to move;

[0008] The controller collects the signal from the positioning sensor and performs logical operations according to the rotation direction of the travel motor to calculate the position of the four-way shuttle.

[0009] Furthermore, determining the current row and column position of the four-way shuttle within the rack includes the following sub-steps:

[0010] Set any shelf location as the origin location, and set the row and column position of the origin location to the first row and first column;

[0011] Taking the origin as the reference point, add numbers from left to right and from top to bottom to determine the row and column values ​​of all the shelves in the shelf.

[0012] Determine the row and column values ​​of the cargo location where the four-way shuttle is currently located.

[0013] Furthermore, calculating the row and column numerical difference between the current row and column position and the target row and column position includes the following steps:

[0014] Subtract the row value of the target row and column position from the row value of the current row and column position to obtain the row value difference;

[0015] Subtract the column value at the target row and column position from the column value at the current row and column position to obtain the column value difference.

[0016] Furthermore, controlling the travel motor to rotate forward or reverse according to the difference between the row and column values ​​to drive the four-way shuttle to move includes the following steps:

[0017] Determine the positive and negative of the row value difference and column value difference respectively. If it is a positive number, the travel motor is controlled to rotate forward. If it is a negative number, the travel motor is controlled to rotate reversely.

[0018] Furthermore, the controller collects the signal from the positioning sensor and performs logical operations based on the rotation direction of the travel motor. The calculation of the position of the four-way shuttle includes the following steps:

[0019] The travel motor drives the four-way shuttle to move the cargo space, triggering the positioning sensor, and the positioning sensor signal is transmitted to the controller for counting;

[0020] Taking the current row and column position as the reference point, the value is added or subtracted according to the number of cargo spaces passed by the four-way shuttle, and the position of the shuttle is calculated in real time.

[0021] Furthermore, taking the current row position as a reference point, adding or subtracting value based on the number of cargo spaces passed by the four-way shuttle, and calculating the position of the four-way shuttle in real time includes the following steps:

[0022] Taking the row value of the current row and column position as the base, if the travel motor rotates forward, the row value is increased according to the number of cargo positions passed by the four-way shuttle. If the travel motor rotates reversely, the row value is decreased according to the number of cargo positions passed by the four-way shuttle.

[0023] Taking the column value of the current row and column position as the base, if the travel motor rotates forward, the column value is added according to the number of cargo positions passed by the four-way shuttle. If the travel motor rotates reversely, the column value is subtracted according to the number of cargo positions passed by the four-way shuttle.

[0024] Furthermore, the following steps are included:

[0025] The controller reads the pulses fed back by the travel motor and calculates the real-time position value of the travel motor;

[0026] Compare the real-time position value of the travel motor with the row and column values ​​of the cargo positions in the shelf to determine the real-time row and column position of the four-way shuttle;

[0027] The position of the four-way shuttle is determined by integrating the pulses fed back by the travel motor and the signals of the two sets of positioning sensors.

[0028] According to the real-time position calculation method of the four-way shuttle according to the embodiment of the present invention, a dual calculation method is used to calculate the current position of the shuttle, which can ensure the accurate position of the shuttle; there is no need to stick a barcode or install an RFID chip, which can avoid the influence of barcode dust and RFID chip damage, thereby reducing costs.

[0029] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the technology as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of a first embodiment of a method for calculating the real-time position of a four-way shuttle vehicle according to an embodiment of the present invention;

[0031] Figure 2 This is a flow chart of a second embodiment of a method for calculating the real-time position of a four-way shuttle vehicle according to an embodiment of the present invention;

[0032] Figure 3 Flowchart of Example 3 of a method for calculating the real-time position of a four-way shuttle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings to further illustrate the present invention.

[0034] First, combine Figures 1-3 A real-time position calculation method according to an embodiment of the present invention is described, which is used to calculate the real-time position of a four-way shuttle vehicle and has a wide range of application scenarios.

[0035] like Figures 1-3As shown, a method for calculating the real-time position of a four-way shuttle according to an embodiment of the present invention is provided. The four-way shuttle travels within a shelf having a plurality of storage locations arranged in a matrix. The method is implemented using a three-point positioning control system comprising a controller and two sets of positioning sensors. The controller is mounted on the four-way shuttle and is signal-connected to the two sets of positioning sensors and a travel motor for driving the four-way shuttle. The travel motor is a servo motor, and the four-way shuttle uses the same servo motor for all four directions of travel. Each set of positioning sensors comprises three, one set of positioning sensors being positioned on opposite sides of the four-way shuttle and the other set of positioning sensors being positioned on the remaining two sides of the four-way shuttle. The method comprises the following steps: determining the current row and column position of the four-way shuttle within the shelf; setting a target row and column position of the four-way shuttle; calculating the row and column numerical difference between the current row and column position and the target row and column position; controlling the travel motor to rotate forward or reverse based on the row and column numerical difference, thereby driving the four-way shuttle; and the controller collecting signals from the positioning sensors and performing logical operations based on the rotation direction of the travel motor to calculate the position of the four-way shuttle. In this embodiment, using the row direction as an example, the three-point positioning system operates as follows: The positioning sensors utilize diffuse reflection photoelectric switches. As a four-way shuttle moves along the rows, a set of row-direction positioning sensors are blocked by the aisles on the shelves, while the column-direction positioning sensors are blocked each time they pass through a shelf. The number of signal transitions from the positioning sensors determines the number of shelves the four-way shuttle has passed in the row direction. This three-point positioning method ensures that the shuttle stops accurately within a shelf. Specifically, two positioning sensors in opposing columns detect the positions of the corresponding column aisles, while the other column-direction positioning sensor serves as a stop trigger. When this positioning sensor signals a change, it indicates that the four-way shuttle has fully entered the shelf, halting its movement. The column-direction positioning principle is the same as the row-direction positioning principle. This three-point positioning system, combined with a calculation method, ensures accurate shuttle positioning without adding additional hardware to the shelves, enabling real-time position calculation during shuttle travel, significantly reducing warehouse costs. It also prevents positioning errors caused by shuttle slippage.

[0036] Further, if Figures 1-3 As shown, in this embodiment, determining the current row and column position of the four-way shuttle in the shelf includes the following sub-steps: setting any cargo location in the shelf as the origin cargo location, and setting the position of the row and column of the origin cargo location to the first row and first column, preferably the cargo location in the corner of the shelf is the origin cargo location; taking the origin cargo location as the reference point, adding numbers in order from left to right and from top to bottom, and subtracting numbers in order from right to left and from bottom to bottom, to determine the row and column values ​​of all cargo locations in the shelf; determining the row and column values ​​of the cargo location where the four-way shuttle is currently located.

[0037] Further, if Figures 1-3 As shown, in this embodiment, calculating the row and column value difference between the current row and column position and the target row and column position includes the following steps: subtracting the row value of the target row and column position from the row value of the current row and column position to obtain the row value difference; subtracting the column value of the current row and column position from the column value of the target row and column position to obtain the column value difference. The calculation is simple and the positioning is convenient.

[0038] Further, if Figures 1-3 As shown, in this embodiment, controlling the travel motor to rotate forward or reverse according to the difference between the row and column values ​​to drive the four-way shuttle to move includes the following steps: judging the positive and negative values ​​of the row value difference and the column value difference respectively; if they are positive, the travel motor is controlled to rotate forward; if they are negative, the travel motor is controlled to rotate reversely.

[0039] Further, if Figures 1-3 As shown, in this embodiment, the controller collects the signal of the positioning sensor and performs logical operations according to the rotation direction of the travel motor. The calculation of the position of the four-way shuttle includes the following steps: the travel motor drives the four-way shuttle to move the cargo position, triggering the positioning sensor, and the positioning sensor signal is transmitted to the controller for counting, and a count is performed every time a cargo position is moved; with the current row and column position as the reference point, the value is added or subtracted according to the number of cargo positions passed by the four-way shuttle, and the position of the four-way shuttle is calculated in real time.

[0040] Further, if Figures 1-3 As shown, in this embodiment, the current row and column position is used as a reference point, and the number of cargo positions passed by the four-way shuttle is added or subtracted. The real-time calculation of the position of the four-way shuttle includes the following steps: using the row value of the current row and column position as the base number, if the travel motor rotates forward, the row value is added according to the number of cargo positions passed by the four-way shuttle; if the travel motor rotates reversely, the row value is subtracted according to the number of cargo positions passed by the four-way shuttle; using the column value of the current row and column position as the base number, if the travel motor rotates forward, the column value is added according to the number of cargo positions passed by the four-way shuttle; if the travel motor rotates reversely, the column value is subtracted according to the number of cargo positions passed by the four-way shuttle. This positioning sensor calculation method combines the controller's counting, the positioning sensor triggering mechanism, and the forward and reverse rotation of the travel motor to accurately calculate the real-time position of the four-way shuttle, ensuring the accurate position of the shuttle and convenient and quick use.

[0041] Further, if Figures 1-3As shown, this embodiment also includes the following steps: a controller reads pulses fed back by the travel motor and calculates the real-time position of the travel motor; since the physical position of the shelf directly corresponds to the pulse count of the servo motor or the encoder position, the real-time position of the four-way shuttle is determined by comparing the real-time position of the travel motor with the row and column values ​​of the shelves; and the position of the four-way shuttle is determined by combining the pulses fed back by the travel motor and the signals from the two sets of positioning sensors. This servo position calculation method utilizes closed-loop control and pulse positioning technology, enabling high-precision position control of the servo motor.

[0042] Example 1: Determine the current row and column position of the four-way shuttle in the shelf; set the target row and column position of the four-way shuttle; calculate the row and column numerical difference between the current row and column position and the target row and column position; control the travel motor to rotate forward or reverse according to the row and column numerical difference, driving the four-way shuttle to move; the controller collects the signal of the positioning sensor and performs logical operations according to the rotation direction of the travel motor to calculate the position of the four-way shuttle. After the initial position column and row of the shuttle are set, the shuttle starts to run after receiving the task; judge based on the difference between the target column or row of the task and the current column or row of the trolley, if the difference is greater than 0, the running direction is forward, and if the difference is less than 0, the running direction is reverse; when the shuttle passes the cargo position, the row direction positioning sensor or the column direction positioning sensor is triggered, the forward direction is counted up, and the reverse direction is counted down. The PLC controller performs logical operations based on the collected positioning sensor signals to calculate the position of the shuttle. For example, the target position of the shuttle task is 4 columns and 1 row, and the current position of the shuttle is 1 columns and 1 row; from column 1 to column 4, the shuttle runs forward. When passing through the cargo grid, the PLC collects the trigger of the row direction positioning sensor, performs logical operations, and adds 1 to the current column value; and so on. When the shuttle is in place, the shuttle position value is updated.

[0043] Example 2: Determine the current row and column position of a four-way shuttle within a shelf; set the target row and column position of the four-way shuttle; calculate the row and column numerical difference between the current row and column position and the target row and column position; control the travel motor to rotate forward or reverse based on the row and column numerical difference, driving the four-way shuttle to move; the controller reads the pulses fed back by the travel motor and calculates the real-time position value of the travel motor; compares the real-time position value of the travel motor with the row and column numerical value of the cargo location within the shelf to determine the real-time row and column position of the four-way shuttle. After the initial row and column position of the shuttle is set, the shuttle begins to operate after receiving the task; the PLC controller reads the real-time position value of the servo and calculates the shuttle position by comparing it with the physical position data of the cargo location. For example, if the target position of the shuttle task is 4 rows and 1 column, and the current position of the shuttle is 1 row and 1 column, when the shuttle begins to operate, the PLC controller reads the real-time position value of the servo and calculates the current position of the shuttle by comparing it with the position value of each cargo location in the PLC data storage area.

[0044] Example 3: Determine the current row position of the four-way shuttle in the shelf; set the target row position of the four-way shuttle; calculate the row value difference between the current row position and the target row position; control the travel motor to rotate forward or reverse according to the row value difference, driving the four-way shuttle to move; the controller collects the signal of the positioning sensor and performs logical operations according to the rotation direction of the travel motor to calculate the position of the four-way shuttle; the controller reads the pulse feedback from the travel motor and calculates the real-time position value of the travel motor; compares the real-time position value of the travel motor with the row value of the cargo position in the shelf to determine the real-time row position of the four-way shuttle, and combines the pulse feedback from the travel motor and the signals of the two sets of positioning sensors to determine the position of the four-way shuttle. Based on the position calculated by the calculation method of the positioning sensor and the calculation method of the servo pulse feedback, and combined with the final stop position of the trolley, the PLC controller determines the current position of the shuttle through calculation and comparison, and updates and uploads it.

[0045] Above, refer to Figures 1-3 A method for calculating the real-time position of a four-way shuttle according to an embodiment of the present invention is described. A dual calculation method is used to calculate the current position of the shuttle, which can ensure the accurate position of the shuttle. There is no need to stick barcodes or install RFID chips, which can avoid the effects of barcode dust and RFID chip damage, thereby reducing costs.

[0046] It should be noted that, in this specification, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, the elements defined by the phrase "comprising..." do not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the elements.

[0047] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description is not intended to limit the present invention. After reading the above description, various modifications and substitutions of the present invention will become apparent to those skilled in the art. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for calculating the real-time position of a four-way shuttle, wherein the four-way shuttle travels in a shelf provided with a plurality of cargo spaces arranged in a matrix. The method is implemented by a three-point positioning system, wherein the three-point positioning system comprises a controller and two sets of positioning sensors; the controller is arranged on the four-way shuttle, and the controller is connected to the two sets of positioning sensors and a travel motor for driving the four-way shuttle by signals; the number of each set of positioning sensors is three, wherein one set of positioning sensors is respectively arranged on two opposite sides of the four-way shuttle, and another set of positioning sensors is respectively arranged on the remaining two sides of the four-way shuttle; the method is characterized in that The method includes the following steps: Determine the current row and column position of the four-way shuttle within the rack; Set the target row position of the four-way shuttle; Calculate the difference between the current row and column position and the target row and column position; According to the difference between the row and column values, the travel motor is controlled to rotate forward or reverse, driving the four-way shuttle to move; The controller collects the signal from the positioning sensor and performs logic operations based on the rotation direction of the travel motor to calculate the position of the four-way shuttle; It also includes the following steps: The controller reads the pulses fed back by the travel motor and calculates the real-time position value of the travel motor; Compare the real-time position value of the travel motor with the row and column values ​​of the cargo positions in the shelf to determine the real-time row and column position of the four-way shuttle; The position of the four-way shuttle is determined by integrating the pulses fed back by the travel motor and the signals from the two sets of positioning sensors; Taking the row direction as an example, the working process of the three-point positioning system is as follows: the positioning sensor adopts a diffuse reflection photoelectric switch, and the four-way shuttle moves along the row direction. At this time, a group of positioning sensors located in the row direction are blocked by the aisles on the shelves, and the positioning sensors located in the column direction are blocked once each time they pass a cargo location. The number of signal conversions of the positioning sensor is used to determine the number of cargo locations passed by the four-way shuttle in the row direction, and the three-point positioning method can ensure the accuracy of the final complete stop in the cargo location. Specifically, the two positioning sensors in the relative column directions respectively detect the positions of the relative column aisles, and the other positioning sensor in the column direction serves as the stop trigger point. When the signal of the positioning sensor changes, it means that the four-way shuttle has completely entered the cargo location and the movement of the four-way shuttle stops. The positioning principle in the column direction is the same as that in the row direction.

2. The method for calculating the real-time position of a four-way shuttle vehicle according to claim 1, wherein: Determining the current row and column position of the four-way shuttle in the rack includes the following sub-steps: Set any shelf location as the origin location, and set the row and column position of the origin location to the first row and first column; Taking the origin as the reference point, add numbers from left to right and from top to bottom to determine the row and column values ​​of all the shelves in the shelf. Determine the row and column values ​​of the cargo location where the four-way shuttle is currently located.

3. The method for calculating the real-time position of a four-way shuttle vehicle according to claim 1 or 2, wherein: Calculating the difference between the current row and column position and the target row and column position includes the following steps: Subtract the row value of the target row and column position from the row value of the current row and column position to obtain the row value difference; Subtract the column value at the target row and column position from the column value at the current row and column position to obtain the column value difference.

4. The method for calculating the real-time position of a four-way shuttle vehicle according to claim 3, wherein: The method of controlling the travel motor to rotate forward or reverse according to the difference between the row and column values ​​to drive the four-way shuttle to move includes the following steps: Determine the positive and negative of the row value difference and column value difference respectively. If it is a positive number, the travel motor is controlled to rotate forward. If it is a negative number, the travel motor is controlled to rotate reversely.

5. The method for calculating the real-time position of a four-way shuttle vehicle according to claim 1, wherein: The controller collects the signal of the positioning sensor and performs logic operation according to the rotation direction of the travel motor to calculate the position of the four-way shuttle, which includes the following steps: The travel motor drives the four-way shuttle to move the cargo space, triggering the positioning sensor, and the positioning sensor signal is transmitted to the controller for counting; Taking the current row and column position as the reference point, the value is added or subtracted according to the number of cargo spaces passed by the four-way shuttle, and the position of the shuttle is calculated in real time.

6. The method for calculating the real-time position of a four-way shuttle as claimed in claim 5, characterized in that: The method of using the current row and column position as a reference point and adding or subtracting value according to the number of cargo spaces passed by the four-way shuttle to calculate the position of the four-way shuttle in real time includes the following steps: Taking the row value of the current row and column position as the base, if the travel motor rotates forward, the row value is increased according to the number of cargo positions passed by the four-way shuttle. If the travel motor rotates reversely, the row value is decreased according to the number of cargo positions passed by the four-way shuttle. Taking the column value of the current row and column position as the base, if the travel motor rotates forward, the column value is added according to the number of cargo positions passed by the four-way shuttle. If the travel motor rotates reversely, the column value is subtracted according to the number of cargo positions passed by the four-way shuttle.

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