Forklift height lifting control method

Abstract

The invention discloses a forklift height lifting control method. The method comprises the steps that the first height of prongs on the forklift, the second height of a portal frame on the forklift and the total height of the prongs and the portal frame are obtained; based on the first height and the second height, the target height difference between the fork tooth and the portal frame is determined, and the target height difference is used for representing the height difference of the portal frame relative to the fork tooth; based on the expected operation height and the total height of the forklift, a target lifting direction and a target control object are determined, the target control object comprises at least one of the following objects: a fork tooth and a portal, and the expected operation height is used for representing the total height which the fork tooth and the portal need to reach when the forklift operates; and on the basis of the target height difference, the total height and the target lifting direction, lifting control is conducted on the target control object, so that the forklift reaches the expected operation height. The technical problem that the control efficiency of the forklift is low in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of forklift control, and more specifically, to a method for controlling the height adjustment of a forklift. Background Technology

[0002] Currently, forklift height control plays a core role in driving the development of automated logistics, especially with the continuous maturation and expansion of unmanned forklift technology. While individual forklift components can independently complete lifting tasks, in complex workflows, the lack of comprehensive inter-mechanical coordination planning leads to a discontinuous and uneven lifting process, thus affecting the efficiency and quality of logistics operations.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This invention provides a forklift height control method to at least solve the technical problem of low control efficiency of forklifts in related technologies.

[0005] According to one aspect of the present invention, a forklift height adjustment control method is provided, comprising: acquiring a first height of the fork tines on the forklift, a second height of the mast on the forklift, and a total height of the fork tines and the mast, wherein the fork tines are structures on the forklift used to carry objects, the mast is a structure on the forklift used to connect the fork tines, the first height represents the height of the fork tines relative to a first initial position, the second height represents the height of the mast relative to a second initial position, the total height represents the overall height of the fork tines and the mast, the first initial position is the lowest position where the fork tines move on the forklift, and the second initial position is the mast... The lowest position moved on the forklift; based on the first height and the second height, the target height difference between the fork teeth and the mast is determined, wherein the target height difference is used to represent the height difference of the mast relative to the fork teeth; based on the expected operating height and total height of the forklift, the target lifting direction and the target control object are determined, wherein the target control object includes at least one of the following: fork teeth, mast, and the expected operating height is used to represent the total height that the fork teeth and mast need to reach when the forklift is operating; based on the target height difference and the total height, the target control object is lifted and lowered based on the target lifting direction so that the forklift reaches the expected operating height.

[0006] According to another aspect of the present invention, an electronic device is also provided, comprising: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods of various embodiments of the present invention during runtime.

[0007] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is executed, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of the present invention.

[0008] According to another aspect of the present invention, a computer program product is also provided, including a computer program that, when executed by a processor, implements the methods of various embodiments of the present invention.

[0009] According to another aspect of the present invention, a computer program product is also provided, including a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the methods of various embodiments of the present invention.

[0010] According to another aspect of the present invention, a computer program is also provided, which, when executed by a processor, implements the methods of the various embodiments of the present invention.

[0011] In this embodiment of the invention, the first height of the fork tines, the second height of the mast, and the total height of the fork tines and mast are obtained. The fork tines are structures on the forklift used to carry objects, and the mast is a structure on the forklift used to connect the fork tines. The first height represents the height of the fork tines relative to a first initial position, the second height represents the height of the mast relative to a second initial position, and the total height represents the overall height of the fork tines and mast. The first initial position is the lowest position the fork tines move on the forklift, and the second initial position is the lowest position the mast moves on the forklift. Based on the first and second heights, the height of the fork tines and mast is determined. The system defines a target height difference for the mast, representing the height difference between the mast and the fork tines. Based on the forklift's expected operating height and total height, it determines the target lifting direction and the target control object. The target control object includes at least one of the following: fork tines and mast. The expected operating height represents the total height that the fork tines and mast need to reach when the forklift is operating. Based on the target height difference and total height, the system performs lifting control on the target control object based on the target lifting direction to ensure the forklift reaches the expected operating height. The system dynamically calculates the current total height of the fork tines and mast based on the acquired first fork height and second mast height. Subsequently, by comparing the expected operating height with the current total height, the system automatically determines the required lifting direction. After determining the lifting direction, the system intelligently analyzes the target height difference and the current total height, flexibly selecting the control object. Through height difference judgment and intelligent selection of the target control object, the system improves forklift lifting control, ensuring that the forklift can efficiently and accurately complete height adjustments in automated operations. This significantly improves the operating efficiency and control accuracy of unmanned forklifts when handling diverse logistics tasks, thus solving the technical problem of low control efficiency of forklifts in related technologies. Attached Figure Description

[0012] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0013] Figure 1 This is a flowchart of a forklift height lifting control method according to an embodiment of the present invention;

[0014] Figure 2 This is a system block diagram of a forklift height lifting control system according to an embodiment of this application;

[0015] Figure 3 This is a schematic diagram of a forklift height lifting control device according to an embodiment of this application. Detailed Implementation

[0016] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0017] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0018] According to an embodiment of the present invention, an embodiment of a forklift height lifting control method is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0019] Figure 1This is a flowchart of a forklift height lifting control method according to an embodiment of the present invention, such as... Figure 1 As shown, the method includes the following steps:

[0020] Step S102: Obtain the first height of the fork teeth on the forklift, the second height of the mast on the forklift, and the total height of the fork teeth and mast.

[0021] Among them, the fork teeth are the structure on the forklift used to carry objects, the mast is the structure on the forklift used to connect the fork teeth, the first height is used to represent the height of the fork teeth relative to the first initial position, the second height is used to represent the height of the mast relative to the second initial position, the total height is used to represent the overall height of the fork teeth and the mast, the first initial position is the lowest position of the fork teeth on the forklift, and the second initial position is the lowest position of the mast on the forklift.

[0022] The fork teeth mentioned above are components on a forklift used to carry and move goods. They are designed to move vertically to accommodate loading and unloading needs of goods at different heights.

[0023] The mast mentioned above is a structure on a forklift used to support the fork teeth and enable their lifting and lowering movements. Controlled by hydraulic cylinders, it can extend and retract in the vertical direction of the forklift to indirectly lift the fork teeth, thus adapting to higher or more complex operating scenarios.

[0024] The aforementioned first height is defined as the height of the fork tooth relative to its lowest position (i.e., the first initial position) on the forklift. This data is collected in real time by a height detection unit (such as a wire encoder) installed at the end of the fork tooth, and is used to precisely control the lifting and lowering of the fork tooth.

[0025] The aforementioned second height refers to the height of the mast relative to its lowest position on the forklift (i.e., the second initial position), which is also obtained in real time by a height detection unit installed on the top of the mast. This height is used to control the telescopic movement of the mast and ensure the coordinated operation of the mast and the fork teeth.

[0026] The total height mentioned above is the vertical height of the fork tines and the mast as a whole. It is the sum of the first height and the second height, and is indirectly obtained by calculating the difference between the height of the mast end and the height of the fork tines. The total height data is used to assess the difference between the forklift's current operating height and the target height, and is the basis for the control logic to determine the lifting direction and the execution of actions.

[0027] First, the height detection unit continuously monitors and records the actual height information of the fork tines and mast, ensuring the real-time nature and accuracy of the data. Then, based on the acquired first and second height data, the control unit calculates the forklift's total height, providing a crucial reference for subsequent lifting control logic. This step emphasizes the independence and accuracy of height data acquisition, ensuring that subsequent control commands are based on the most realistic and immediate forklift status, thereby achieving precise control of the fork tines and mast lifting and avoiding incoordination or control errors.

[0028] The above ensures the accuracy and real-time nature of height information collection, providing a solid data foundation for the forklift height control in this application embodiment. By accurately acquiring the height information of the fork teeth and mast, the system can intelligently determine the lifting direction and control object based on the difference between the current operating state and the target height, achieving smooth and efficient coordinated lifting control. This effectively improves the operational stability and positioning accuracy of the forklift in unmanned operating environments and reduces the risk of impact and damage caused by improper control.

[0029] For example, suppose the forklift is currently performing the task of removing goods from a high shelf, with the target height being the height of a specific shelf position. The system first obtains the information of the lowest position of the fork teeth (first height) from the first cable encoder, and obtains the information of the mast also being at its lowest position (second height) from the second cable encoder. Since both the fork teeth and the mast are in their initial positions, the system calculates the total height as the sum of the two, which is the minimum height state of the forklift.

[0030] Subsequently, by analyzing the target height information, the control unit determines whether lifting control is required for the forks, the mast, or both, to achieve the target height. Based on the difference between the current total height and the target height, the control unit dynamically adjusts the output percentage of the hydraulic cylinders using a trapezoidal acceleration / deceleration algorithm. This ensures smooth and continuous lifting of the forks and mast, avoiding abrupt changes and overshoot. Furthermore, it eliminates the need for an additional load measurement mechanism, directly relying on real-time feedback from the height detection unit for control improvements, achieving high-precision positioning and stable lifting.

[0031] For example, if the target height is within the lifting range of the fork tines, the system will prioritize driving the fork tin cylinders to smoothly lift the fork tines at a set acceleration until the target height is reached. If the fork tines have reached their maximum lifting position but the target height has not yet been achieved, the system will automatically switch to control the mast cylinders, using the current cylinder output percentage of the fork tines to continue lifting the mast until the height difference is compensated. Throughout the process, the control unit continuously monitors height changes to ensure that the system can smoothly decelerate until it stops when approaching the target height, enabling precise loading and unloading of goods and improving the operational efficiency and safety of the unmanned forklift in complex working environments.

[0032] Through the above steps, the control system of this application embodiment realizes intelligent and smooth control of the lifting process of the fork and the gantry. Its beneficial effects are that it improves the operation accuracy, stability and flexibility. Especially in unmanned operation scenarios, it can effectively avoid the operation risks caused by uncoordinated actions or insufficient control accuracy.

[0033] Step S104: Determine the target height difference between the fork and the gantry based on the first height and the second height.

[0034] The target height difference is used to represent the height difference between the gantry and the fork teeth.

[0035] The aforementioned target height difference refers to the actual vertical displacement of the mast relative to the fork teeth, which is the core control parameter in this application embodiment. The calculation of the target height difference is based on the real-time acquisition of the first height of the fork teeth and the second height of the mast, reflecting the height difference that the mast and fork teeth need to adjust in coordination under the current forklift operating state in order to achieve precise control of the target operating height.

[0036] This application embodiment analyzes the first height and the second height to intelligently calculate the target height difference and determine the vertical displacement requirement of the mast relative to the fork teeth. This process is equivalent to establishing a dynamic model of the height difference in the automated control system, intelligently analyzing the difference between the current working height of the forklift and the target working height, thereby guiding subsequent lifting control decisions.

[0037] The embodiments of this application can intelligently identify the difference between the current working state and the target height without the need for additional load detection. By accurately calculating the target height difference, the lifting action of the fork teeth and mast is dynamically adjusted to ensure the smooth and precise operation of the forklift under different height requirements.

[0038] For example, when an unmanned forklift is performing a goods stacking task with a target height of 4 meters, and the current fork height is 1.5 meters and the mast height is 0.5 meters, the system analyzes and calculates that the forklift's current total height is 2 meters. Then, it determines the target height difference to be 2.5 meters (the difference between the target height of 4 meters and the current total height of 2 meters), meaning the mast needs to be raised 2.5 meters relative to the forks to reach the target working height. Based on this analysis, this embodiment can intelligently determine the priority and rhythm of lifting control, precisely guide the coordinated movement of the forks and mast, and ensure that the forklift completes height adjustments smoothly and efficiently without manual intervention or load information, directly improving operational safety and efficiency.

[0039] This application's embodiments can intelligently analyze and determine the target height difference between the mast and the fork teeth without relying on additional load detection, providing a crucial basis for the formulation of subsequent lifting control strategies. The accurate calculation of the target height difference ensures that the forklift can intelligently adjust the lifting actions of the fork teeth and mast based on the difference between the current operating state and the target operating height during automated operation. This significantly improves the accuracy and stability of the operation, reduces damage and operational risks caused by uncoordinated actions or improper control, and achieves a high degree of automation and intelligence in forklift operation.

[0040] For example, in an automated warehousing environment, an unmanned forklift needs to accurately place goods on a shelf with a height of 5 meters. Currently, the first height of the fork teeth is 1.2 meters, and the second height of the mast is 0.8 meters, meaning the current total height of the forklift is 2 meters. The system then calculates the target height difference and determines it to be 3 meters (i.e., the difference between the target height of 5 meters and the current total height of 2 meters). Based on this analysis, the embodiments of this application can intelligently determine the priority of lifting control, prioritizing raising the fork teeth to their maximum adjustable height, and then seamlessly switching to mast control until the target height difference is fully compensated, achieving precise control of the 5-meter target working height. The entire process requires no manual intervention and does not rely on load information, directly improving the operating efficiency and safety of the forklift in complex working environments, demonstrating the high level of intelligence and responsiveness of automated control.

[0041] Step S106: Based on the expected working height and total height of the forklift, determine the target lifting direction and the target control object.

[0042] The target control object includes at least one of the following: fork teeth, mast, and the expected working height is used to indicate the total height that the fork teeth and mast need to reach when the forklift is performing operations.

[0043] The aforementioned expected working height defines the total height that the forklift and mast combination needs to reach when performing a specific task. The expected working height, set based on operational requirements, forms the basis for the system's decisions regarding lifting direction and target control, ensuring the forklift can accurately adapt to different work scenarios, whether it's handling goods or stacking shelves.

[0044] The aforementioned target lifting direction refers to the lifting direction automatically determined by the system based on the difference between the forklift's current total height and the expected working height. This decision-making logic ensures the continuity and efficiency of the forklift's actions, avoids unnecessary reverse operations, and reduces energy waste and time loss during the lifting process.

[0045] The aforementioned target control objects refer to the forklift components that the system needs to prioritize adjusting under specific lifting directions, including the fork teeth and mast. By intelligently analyzing the difference between the current height and the expected working height, the system can dynamically select the target control objects to ensure the smoothness and positioning accuracy of the forklift during lifting, thereby improving operational efficiency.

[0046] This application's embodiments intelligently analyze the direction of lifting and lowering movements and prioritize the controlled components based on real-time total forklift height and the set expected working height. This process is similar to a human driver quickly determining the vehicle's forward or backward direction and adjusting which parts of the vehicle to adapt to environmental changes when facing different road conditions. Through this intelligent decision-making, the system ensures that each lifting and lowering operation is the most direct response to the current operational needs, achieving automated and precise control of the forklift.

[0047] In automated logistics operations, when the system determines that the expected working height is a specific value and the forklift's current total height is insufficient, it automatically identifies the target lifting direction as upward and determines the priority target control object to lift based on the current state of the forks and mast, achieving the target working height with minimal adjustments. This not only improves the forklift's operational flexibility but also reduces lifting delays caused by complex control logic, directly improving operational accuracy and efficiency.

[0048] This application embodiment can intelligently analyze and determine the target lifting direction and target control object in an automated operating environment based on real-time height information and a preset expected operating height, achieving a high degree of automation and intelligence in forklift lifting control. This technology not only improves the operational flexibility and precision of forklifts but also reduces lifting action delays caused by complex control logic, providing technical assurance for the efficient and safe operation of unmanned forklifts. Its advantages are particularly evident in logistics environments where operating heights and cargo handling frequently change.

[0049] Specifically, the system can monitor the vertical displacement of the fork tines and mast in real time, instantly obtaining the current load height of the fork tines and the extension / retraction status of the mast. Based on this real-time data and preset operating height requirements, through intelligent calculation and analysis, the system automatically determines the direction of lifting control (target lifting direction) and the priority control target component (target control object), ensuring the continuity and smoothness of the action whether lifting the fork tines or extending the mast. This intelligent control strategy avoids the response lag caused by human judgment errors or high logical complexity in traditional control, significantly improving the height adaptability and control efficiency of unmanned forklifts during operation. In practical applications, especially in scenarios where goods of different heights are frequently handled in automated warehouses, this technology can ensure that the forklift can smoothly and efficiently adjust to the required operating height, reducing operational errors and damage, and directly promoting the improvement of automation levels in the logistics industry.

[0050] Step S108: Based on the target height difference and total height, the target control object is raised or lowered according to the target lifting direction so that the forklift reaches the expected working height.

[0051] The aforementioned expected operating height is a key operating parameter in this application embodiment. It defines the target height that the forklift and mast combination must achieve when performing a specific task. The setting of the expected operating height depends on the operational requirements, such as the stacking height of goods and the location of rack access points, and is the ultimate goal of the system for lifting control and motion coordination.

[0052] The aforementioned target height difference reflects the actual lifting requirements of the mast relative to the fork teeth. It is determined through calculation based on real-time data collected of the first fork tooth height and the second mast height, and is used to guide subsequent lifting control strategies to ensure that the forklift can be precisely adjusted to the required height.

[0053] The total height mentioned above represents the overall position of the fork and mast in the vertical direction. It is the sum of the first height and the second height and is used to assess the difference between the current forklift operation status and the expected operation height. It is the basis for determining the lifting direction and the controlled object.

[0054] The aforementioned target lifting direction refers to the lifting direction automatically determined by the system based on the difference between the current total height and the expected working height. Determining the target lifting direction ensures the continuity and efficiency of lifting control, avoiding unnecessary and wasted movement.

[0055] The aforementioned target control object refers to the forklift components that need to be adjusted first under a defined target lifting direction, including the fork teeth or mast. Selecting the target control object ensures the execution of the action and reduces delays and errors caused by complex control logic.

[0056] This embodiment of the application intelligently determines the target lifting direction and the target control object based on the analysis results of the target height difference and the total height, thereby achieving precise adjustment of the forklift height. This process is similar to a commander quickly deciding on the direction of action and the priority of troop deployment based on battlefield situation analysis, ensuring that the system can respond to operational needs efficiently and accurately, and avoiding unnecessary actions and impacts caused by improper control logic of components.

[0057] For example, in an automated forklift pickup operation, the system needs to adjust the forklift to a target working height of 3 meters to accurately pick up goods from the shelf. Currently, assuming the first height of the fork teeth is 1 meter and the second height of the mast is 1.5 meters, in step S104, the system calculates a target height difference of 0.5 meters, meaning the mast needs to descend an additional 0.5 meters relative to the fork teeth for the forklift to reach the target height. Based on this difference, in step S108, this embodiment intelligently determines the target lifting direction (i.e., the descent direction) and selects the target control object (i.e., the mast) for control, achieving precise control of the target working height with minimal adjustment. The system uses a hydraulic cylinder actuator to smoothly adjust the mast descent according to a set acceleration until the total height precisely matches the target working height, significantly improving the accuracy and efficiency of the operation and reducing motion errors and damage.

[0058] By implementing step S108, this embodiment of the application can automatically select the target lifting direction and the target control object based on the analysis of the target height difference and the total height, thereby achieving precise height adjustment and motion control of the forklift. This technology reduces the delay in lifting actions, enhances the continuity and safety of operations, directly improves the operating efficiency and control precision of unmanned forklifts in automated warehouses, and reduces damage and operational risks caused by improper control.

[0059] For example, suppose an unmanned forklift is performing a task that requires raising the forks to a target working height of 2.5 meters to move goods at that height. Currently, the total height of the forklift is 1.5 meters (the first height of the forks is 1 meter, and the second height of the mast is 0.5 meters). The system calculates in step S104 that the target height difference is 1 meter, meaning that the overall height of the forks and mast needs to be raised by 1 meter. In step S108, the system intelligently determines that the target lifting direction is upward and selects the target control object (in this case, the forks) for priority control. The system first drives the fork cylinder to smoothly raise the forks to their maximum allowable height according to the set acceleration, and then seamlessly switches to mast control, continuing to raise the mast according to the percentage of cylinder output in the previous step until the entire forklift reaches the target working height. The entire process requires no additional load information and directly relies on height detection and control algorithms to achieve smooth and precise lifting control of the forklift in an unmanned operating environment, significantly improving operational efficiency and safety.

[0060] Through the above steps, the first height of the fork tines, the second height of the mast, and the total height of the fork tines and mast are obtained. The fork tines are the structure on the forklift used to carry objects, and the mast is the structure on the forklift used to connect the fork tines. The first height represents the height of the fork tines relative to a first initial position, the second height represents the height of the mast relative to a second initial position, and the total height represents the overall height of the fork tines and mast. The first initial position is the lowest position the fork tines move on the forklift, and the second initial position is the lowest position the mast moves on the forklift. Based on the first and second heights, the height of the fork tines and mast is determined. The system determines the target height difference of the mast, where the target height difference represents the height difference between the mast and the forks. Based on the expected operating height and total height of the forklift, the system determines the target lifting direction and the target control object, where the target control object includes at least one of the following: forks and mast. The expected operating height represents the total height that the forks and mast need to reach when the forklift is operating. Based on the target height difference and total height, the system performs lifting control on the target control object based on the target lifting direction to enable the forklift to reach the expected operating height. The system dynamically calculates the current total height of the forks and mast based on the acquired first fork height and second mast height. Subsequently, by comparing the expected operating height with the current total height, the system automatically determines the required lifting direction. After determining the lifting direction, the system intelligently analyzes the target height difference and the current total height, flexibly selects the control object, and improves the forklift lifting control through height difference judgment and intelligent selection of the target control object. This ensures that the forklift can efficiently and accurately complete height adjustments in automated operations, thereby significantly improving the operating efficiency and control accuracy of unmanned forklifts when handling diverse logistics tasks, and thus solving the technical problem of low control efficiency of forklifts in related technologies.

[0061] Optionally, based on the expected operating height and total height of the forklift, the target lifting direction and target control object are determined, including: determining the target lifting direction based on the expected operating height and total height; and determining the target control object based on the first lifting state of the fork teeth, the second lifting state of the mast, and the target lifting direction, wherein the first lifting state is used to indicate whether to perform a lifting operation on the fork teeth, and the second lifting state is used to indicate whether to perform a lifting operation on the mast.

[0062] The aforementioned expected operating height defines the target height that the forklift must reach when performing a task. This height is set based on operational requirements, such as the storage height of the rack or the stacking height of goods.

[0063] The total height mentioned above represents the current state of the forklift, that is, the total displacement of the fork teeth and mast in the vertical direction, which is obtained by adding the first height of the fork teeth and the second height of the mast.

[0064] The target lifting direction mentioned above is based on a comparison between the expected working height and the total height. The system automatically determines whether the forklift needs to be raised or lowered to achieve the target working height. This decision is a crucial step in the lifting control process, ensuring the correct execution of subsequent control logic.

[0065] The first lifting state mentioned above is a status indicator of whether the fork is performing a lifting operation. It is used by the system to determine whether the fork is currently in an operable state and is an important basis for formulating subsequent lifting control strategies.

[0066] The second lifting state described above is a description of whether the mast is undergoing lifting operation. Together with the first lifting state, it forms the basis for the system to judge the overall lifting status of the forklift, determining whether the mast needs to be adjusted and how to adjust it.

[0067] This application's embodiment first determines the target lifting direction based on the expected working height and the current total height, that is, it determines whether the forklift needs to rise or fall to reach the target working height. Subsequently, based on the first lifting state of the fork tines and the second lifting state of the mast, the system intelligently selects the target control object, that is, after determining the lifting direction, it determines whether to prioritize controlling the fork tines or the mast for lifting operations, ensuring the continuity of the action and maximizing efficiency.

[0068] The embodiments of this application enable intelligent decision-making based on the current state of the forklift and the target working height, ensuring precise selection of the direction of lifting operations and the controlled object, and improving the response speed and control accuracy of the forklift in automated operating environments. This technical effect directly reduces unnecessary operational delays and energy waste, improves forklift operation processes, and enhances the operating efficiency and safety of unmanned forklifts in complex logistics environments.

[0069] For example, suppose the forklift's target operating height is 4.5 meters, while the current total height is 2 meters (the first height of the fork teeth is 1 meter, and the second height of the mast is 1 meter). The system analyzes and determines that the target lifting direction is upward, then judges the lifting status of the fork teeth and the mast. Based on the first and second lifting statuses, the system intelligently determines the object to be controlled first. Since the fork teeth have not yet reached their maximum allowable height, the system selects the fork teeth as the target control object, prioritizing the lifting of the fork teeth to their maximum height, and then seamlessly switches to mast control, continuing to lift the mast until the forklift as a whole reaches the expected operating height. This process ensures the continuity and smoothness of the operation, avoiding forklift impacts or overshoots caused by improper control, and reducing component wear and operational risks.

[0070] For example, suppose an unmanned forklift is handling goods in an automated warehousing system, needing to place the goods at a height of 5 meters. Currently, the total height of the forklift is 2.5 meters (the first height of the forks is 1.5 meters, and the second height of the mast is 1 meter). The system first compares the expected working height with the total height, determining that the target lifting direction is upward. Then, analyzing the lifting status of the forks and mast, the system finds that the forks still have room to rise, so it first raises the forks to their maximum height as the target control object; once the forks reach their upper limit, the system immediately switches to mast control, continuing to raise the overall height of the forklift until the expected working height is reached. Throughout the process, this embodiment ensures the continuity and smoothness of the lifting action, requiring no additional load information, and directly relying on height detection and control algorithms to achieve precise and safe control of the forklift in an unmanned operating environment, significantly improving the efficiency of logistics automation.

[0071] Optionally, the target lifting direction is determined based on the expected working height and the total height, including: if the total height is less than the expected working height, the target lifting direction is determined to be an upward direction; if the total height is greater than the expected working height, the target lifting direction is determined to be a downward direction.

[0072] By comparing the current total height of the unmanned forklift with the expected working height, the target lifting direction is quickly determined. If the current total height is less than the expected working height, the target lifting direction is determined to be upward; conversely, if the current total height is greater than the expected working height, the target lifting direction is determined to be downward. This determination process is the foundation of automated control. It's like a navigator confirming the relationship between the destination and the current location before driving, providing clear directional guidance for subsequent path planning. Through this determination, the embodiments of this application can ensure the continuity and accuracy of lifting actions, reduce unnecessary movements, and improve operational efficiency.

[0073] This application simplifies control logic, avoids complex calculations, and directly determines the lifting direction based on simple height comparison results. This technology significantly reduces system response time, improves the adaptability of unmanned forklifts to operational needs, and reduces the skill requirements for operators, making automated control more widespread and practical.

[0074] For example, in an automated forklift pickup scenario, assuming the forklift's current total height is 2.5 meters and it needs to retrieve goods from a rack with a height of 5 meters, the expected working height is 5 meters. By comparing the total height with the expected working height, the system quickly determines the target lifting direction as upward. This step lays the foundation for subsequent control of the fork teeth and mast's upward movement, ensuring that the forklift can be raised smoothly and efficiently to the required height without stopping midway to analyze complex conditions or performing unnecessary lowering operations.

[0075] By determining the target lifting direction, this embodiment of the application can directly decide whether the unmanned forklift should lift or lower, thereby ensuring the continuity and directionality of the forklift's movements. This automatic judgment based on height comparison greatly simplifies the control process and improves the response speed and operational accuracy of the unmanned forklift in automated operating environments. In practical applications, this technology reduces reliance on operators, lowers operational difficulty, and also reduces wear and tear on components caused by improper control, extending the equipment's lifespan and directly improving the operational efficiency and economy of the unmanned forklift.

[0076] Optionally, the target control object is determined based on the first lifting state of the fork tines, the second lifting state of the gantry, and the target lifting direction, including: if the target lifting direction is an upward direction, determining whether the fork tines have reached their maximum lifting height based on the first lifting state; if the fork tines have not reached their maximum lifting height, and the maximum lifting height is greater than or equal to the expected working height, determining the target control object as the fork tines; if the fork tines have not reached their maximum lifting height, and the maximum lifting height is less than the expected working height, determining the target control object as both the fork tines and the gantry; if the fork tines have reached their maximum lifting height, determining the target control object as the gantry.

[0077] The target lifting direction mentioned above is the adjustment direction automatically determined by the system after comparing the current total height of the unmanned forklift with the expected working height, to ensure that the forklift can smoothly reach the required working height.

[0078] The first lifting state described above describes the current state of the fork, especially checking whether the fork has reached its maximum permissible lifting height. This information is crucial for determining the next control action.

[0079] The maximum lifting height of the fork tines mentioned above is the limit of the height that the fork tines can safely and effectively lift. This parameter is set at the beginning of the forklift design and is related to the physical structure and safety specifications of the forklift.

[0080] The target control object mentioned above refers to the forklift component that the system selects to control based on the target lifting direction and the current fork tooth and mast status. It can be the fork tooth, the mast, or both simultaneously.

[0081] When the target lifting direction is determined to be upward, this embodiment further determines whether the fork has further lifting space based on the first lifting state of the fork. If the fork has not yet reached its maximum lifting height, and this maximum lifting height is sufficient or just meets the requirement of the expected working height, then the fork becomes the target control object, and the system will prioritize controlling the fork to rise until the expected working height is reached. However, if the maximum lifting height of the fork is insufficient to cover the difference in the expected working height alone, even if the fork still has lifting potential, the system will determine the target control objects as the fork and the mast. This means that the fork will first rise to its maximum height, and then the mast will continue to undertake the task of lifting the forklift to the expected working height. Finally, if the fork has already reached its maximum lifting height, regardless of whether the fork has reached the expected working height, the system will determine the target control object as the mast, so as to utilize the mast's lifting capacity to continue lifting the forklift.

[0082] This series of decision-making logics reflects the intelligent allocation of control over various components in the embodiments of this application. Based on the different lifting states and capabilities of the fork teeth and mast, the system can flexibly adjust the control strategy to ensure efficient lifting operations. By real-time monitoring and intelligent judgment of the lifting component status, the problems of disjointed actions or overuse of a certain component caused by a single control method are avoided, thereby improving the overall operating efficiency of the forklift and the lifespan of its components.

[0083] This application's embodiments can intelligently allocate control resources to appropriate target control objects based on the current state and operational needs of the unmanned forklift. Whether controlling the forks or mast individually, or controlling both collaboratively, the aim is to precisely adjust the forklift to the expected working height with the shortest time and least energy consumption. This technology directly improves the forklift's operational flexibility and response speed, reduces operational complexity, and ensures stability and efficiency under various operational conditions.

[0084] For example, in an automated warehouse scenario using unmanned forklifts, suppose the forklift's current total height is 2.5 meters, and it needs to retrieve goods from a rack with a height of 5 meters, with an expected operating height of 5 meters. The system first determines the target lifting direction as upward. Considering that the maximum lifting height of the forks is 2 meters, and the forklift needs to rise another 2.5 meters to reach the expected operating height of 5 meters, the forks become the first target control object, and the system controls the forks to rise to their maximum height. Since the maximum lifting height of the forks is insufficient to cover the remaining 0.5-meter difference, the mast is then designated as the second target control object, and the forklift continues to be raised until the predetermined height of 5 meters is reached, completing the retrieval task.

[0085] For example, suppose an unmanned forklift is performing a handling task, requiring the forks to be raised to a height of 4 meters to move goods. The current total height of the unmanned forklift is 2 meters, with the forks at 1 meter and the mast at 1 meter. Based on the maximum lifting height of the forks being 2 meters, and considering the expected working height is higher than the current total height, this embodiment determines the target lifting direction as upward. Since the maximum lifting height of the forks matches the expected working height, the system first identifies the forks as the target control object and controls them to rise to their maximum height, from the current 1 meter to the maximum permissible 3 meters (2 meters original height + 1 meter lifting). After the forks reach their maximum lifting height, the system again determines that the total height of the forklift (3 meters + 1 meter = 4 meters) is still lower than the expected working height of 4 meters. Therefore, the mast is designated as the next target control object, and the system continues to control the mast to rise to the required height, ultimately achieving precise adjustment of the unmanned forklift to the expected working height of 4 meters, completing the handling task.

[0086] This process demonstrates the high efficiency and intelligence of the control logic in the embodiments of this application. By accurately identifying the lifting status and capabilities of each component, it ensures that the unmanned forklift can accurately and smoothly reach the required height with minimal operating steps and energy consumption, thereby improving the working efficiency and safety of the unmanned forklift in the automated warehousing environment.

[0087] Optionally, the target control object is determined based on the first lifting state of the fork, the second lifting state of the gantry, and the target lifting direction, including: if the target lifting direction is a downward direction, determining whether the gantry has reached its maximum downward height based on the second lifting state; if the gantry has not reached its maximum downward height, and the maximum downward height is less than or equal to the expected working height, determining the target control object as the gantry; if the gantry has not reached its maximum downward height, and the maximum downward height is greater than the expected working height, determining the target control object as the fork and the gantry; if the gantry has reached its maximum downward height, determining the target control object as the fork.

[0088] The target lifting direction is automatically determined based on the difference between the current total height of the unmanned forklift and the expected working height. The indicator system adjusts the height of the forklift upwards or downwards to meet the operational requirements.

[0089] The aforementioned second lifting state reflects whether the gantry has reached its maximum permissible descent height, and this information is crucial for identifying the target controlled object in the descent direction.

[0090] The maximum descent height of the mast mentioned above is the limit position at which the mast can be safely and effectively lowered. This parameter is determined by the physical design and safety specifications of the unmanned forklift.

[0091] The aforementioned expected operating height is the operating point height that the unmanned forklift needs to reach when performing a task. It is set according to specific task requirements, such as the height of the position for placing or retrieving goods.

[0092] When the target lifting direction is the lowering direction, this embodiment of the application determines whether the gantry has room for further descent based on the second lifting state of the gantry. If the gantry has not reached its maximum descent height, and this maximum descent height is sufficient or exactly meets the requirements of the expected working height, then the gantry will become the target control object, and the system will prioritize controlling the gantry to descend until the total height reaches the expected working height. However, if the maximum descent height of the gantry exceeds the expected working height, even if the gantry still has descent potential, the system will determine the target control objects as the fork and the gantry. This means that the gantry will first descend to the difference between the expected working height and the actual working height, and then the fork will continue to adjust to achieve a more precise position. Finally, if the gantry has reached its maximum descent height, regardless of whether the expected working height has been reached, the fork will be determined as the next target control object, and the system will control the fork to descend to meet the working height requirements.

[0093] This application can flexibly adjust the control strategy according to the lifting status and capacity of each component, ensuring that the forklift can be accurately adjusted to the required height with the fewest adjustment steps and the shortest time, while reducing the overuse of individual components and extending the forklift's lifespan.

[0094] This application's embodiment can intelligently allocate control resources based on the current height status and expected working height of the unmanned forklift, ensuring a smooth and efficient descent operation. This technology directly reduces operational steps, lowers energy consumption, improves operational accuracy, and ensures the efficiency and safety of unmanned forklifts in automated warehousing environments.

[0095] For example, suppose the current total height of the unmanned forklift is 5 meters, and a lowering operation is required, with an expected working height of 2 meters. The system determines the lowering direction based on the target lifting direction and then checks the second lifting status of the mast. If the maximum lowering height of the mast is 3 meters, which is not reached, and the mast lowering to 2 meters would meet the expected working height requirement, the system will determine the mast as the target control object and control the mast to smoothly lower to 2 meters. If the maximum lowering height of the mast is greater than the difference between the expected and actual working heights, even if there is sufficient space for the mast to lower, the system will, after the mast lowers to 2 meters, use the forks as the next target control object and fine-tune the fork height to the expected working height to ensure operational accuracy.

[0096] For example, in an automated warehousing scenario using an unmanned forklift, assuming the forklift's current total height is 4.5 meters, and the forks need to be lowered to a height of 1 meter to place goods, the expected operating height is 1 meter. The mast's current height is 3 meters, and its maximum lowering height is 3 meters, meeting the expected operating height requirement. The system determines the target lifting direction to be the lowering direction. Since the mast has not reached its maximum lowering height, and lowering to 1 meter is sufficient, the system uses the mast as the target control object, controlling the mast to smoothly lower to 1 meter, thus adjusting the overall height of the forklift to meet the height requirement for placing goods. If the mast has lowered to 1.5 meters but is still higher than the expected operating height, the system will automatically switch the forks to the next target control object, controlling the forks to lower further to 1 meter to ensure precise placement.

[0097] The embodiments of this application employ intelligent decision-making capabilities in descent control, avoiding unnecessary excessive descent, reducing energy waste during operation, and ensuring high-precision adjustment of the working height, directly improving the safety and efficiency of unmanned forklifts when handling goods.

[0098] Optionally, based on the target height difference and total height, and based on the target lifting direction, the target controlled object is lifted and lowered to enable the forklift to reach the expected working height. This includes: determining multiple control curves based on the target height difference and total height, wherein different control curves correspond to different accelerations; and controlling the target controlled object sequentially according to the multiple control curves based on the target lifting direction to enable the forklift to reach the expected working height.

[0099] The aforementioned target height difference is the vertical distance between the expected working height and the current total height. This parameter is used to measure the height that the unmanned forklift needs to adjust to reach the target working point and is the basis for the system to determine the lifting direction and control strategy.

[0100] The control curves described above represent the relationship between the percentage of cylinder output and time during the lifting control process of the unmanned forklift. By setting different accelerations, each control curve depicts a unique lifting rate variation pattern to adapt to different operational needs and forklift conditions.

[0101] The control curves for different accelerations described above reflect the system's ability to adjust the lifting speed according to different situations. The magnitude of the acceleration can directly affect the speed and stability of the forklift in reaching the expected working height, which is a key feature in this application embodiment that improves the forklift's operational flexibility and response speed.

[0102] The target lifting direction mentioned above is determined based on the comparison between the expected working height and the total height, indicating whether the unmanned forklift should rise or fall to meet the height requirements of the working point.

[0103] This application embodiment generates a series of control curves with different accelerations by analyzing the target height difference and the total height. Each curve corresponds to a specific lifting rate change pattern. Based on the target lifting direction, the system successively refers to these control curves to perform fine control on the target controlled object (fork teeth or mast). If the target lifting direction is upward, the system will select a suitable curve from the series of control curves to lift the fork teeth or mast with appropriate acceleration, or both may work together. Conversely, if it is downward, the system will also perform smooth descent control according to the curve to ensure that the forklift can smoothly and efficiently reach the expected working height.

[0104] Based on the target height difference and the current state of the forklift, control curves can be dynamically generated and selected, and the lifting rate can be precisely controlled by adjusting the acceleration. This not only improves the operational accuracy of the unmanned forklift but also ensures stability when rapidly changing the working height, avoiding overshoot or impact caused by improper control and reducing component wear.

[0105] This application's embodiments, by generating and applying control curves with different accelerations, enable precise and stable lifting control of the target object in the target lifting direction. This allows the unmanned forklift to quickly respond to operational needs while maintaining smooth movement and accurate positioning. This technical effect directly reduces operation time, improves operational efficiency, and reduces equipment failures and damage, ensuring the long lifespan and high reliability of the unmanned forklift in automated operating environments.

[0106] For example, if the current total height of the unmanned forklift is 1.5 meters, and the expected working height is 3 meters, the target height difference is 1.5 meters. The system first determines the target lifting direction as upward. Next, the system selects a suitable curve from a preset control curve library. The acceleration set on this curve ensures that the forklift smoothly reaches the expected working height within a specified time without excessive energy consumption or unnecessary impact. The system will gradually raise the forks according to the selected control curve. When the forks reach their maximum permissible height, it seamlessly switches to mast control until the unmanned forklift reaches the expected working height of 3 meters.

[0107] For example, assuming the unmanned forklift is currently at a total height of 2 meters, in order to move goods located at a height of 3.5 meters, the system needs to lift the entire forklift to the expected working height of 3.5 meters. First, the system determines the target lifting direction as the upward direction. Then, based on the target height difference of 1.5 meters and the current total height, it selects a suitable curve from a preset control curve library. The acceleration setting of this curve ensures that the unmanned forklift can smoothly lift to 3.5 meters in the shortest time and with minimal impact. The system first lifts the forks to their maximum permissible height of 2 meters according to the selected control curve, and then controls the mast to continue rising until the entire unmanned forklift reaches a height of 3.5 meters, completing the goods handling task. In this process, the embodiments of this application demonstrate its intelligence and efficiency in lifting control, ensuring rapid response and precise operation of the unmanned forklift in automated warehouses, while extending the service life of the equipment and improving the overall safety and economy of the operation.

[0108] This application provides an intelligent solution for lifting control of unmanned forklifts. By generating control curves adapted to different height requirements, the system can dynamically adjust the acceleration during the lifting process based on the target lifting direction and the state of the controlled object. This ensures smooth and efficient lifting control, directly propelling the forklift to quickly and accurately reach the expected working height, reducing waiting and adjustment time during operation, and improving the continuity and efficiency of the overall work process. Simultaneously, this control strategy also reduces equipment impact caused by rapid lifting, protecting the long-term health of the equipment and extending the service life of the unmanned forklift.

[0109] Optionally, the multiple control curves include an acceleration control curve, a constant speed control curve, and a deceleration control curve. Based on the target lifting direction, the target controlled object is controlled sequentially according to the multiple control curves to make the forklift reach the expected working height. This includes: accelerating the target controlled object based on the acceleration control curve according to the target lifting direction to make the forklift reach a first preset working height, where the first preset working height is the working height the target controlled object is to reach during the acceleration control phase; controlling the target controlled object at a constant speed based on the constant speed control curve according to the target lifting direction to make the forklift move from the first preset working height to a second preset working height, where the second preset working height is the working height the target controlled object is to reach during the constant speed control phase; and decelerating the target controlled object based on the deceleration control curve according to the target lifting direction to make the forklift move from the second preset working height to the expected working height.

[0110] The acceleration control curve described above guides the operation of the unmanned forklift during the initial lifting phase. It achieves a smooth start from a standstill to rising or falling by gradually increasing the output percentage of the hydraulic cylinders. During this phase, the rate of adjustment is determined by the slope of the curve; the steeper the slope, the faster the acceleration.

[0111] The aforementioned first preset working height is the working height that the target controlled object (fork or gantry) is to reach at the end of the acceleration control phase, and it is the target point of the acceleration control phase.

[0112] The aforementioned constant speed control curve continues after the acceleration phase to maintain the stability of the cylinder output percentage, ensuring that the target controlled object rises or falls at a constant speed from the first preset working height to the second preset working height, thus achieving smooth motion control.

[0113] The aforementioned second preset working height is the working height that the target controlled object is expected to reach at the end of the constant speed control phase; it is the target point of the constant speed control phase. It is usually close to the expected working height, but with a margin left for deceleration control.

[0114] The aforementioned deceleration control curve is used to guide the operation of the target controlled object from the second preset working height to the expected working height. By gradually reducing the output percentage of the hydraulic cylinder, smooth deceleration is achieved until a stop is reached, avoiding shock and unstable stopping when reaching the expected working height.

[0115] In this embodiment, after the target lifting direction is determined, the system first performs acceleration control on the target controlled object based on the acceleration control curve. This stage starts from a stationary state and gradually increases the output percentage of the hydraulic cylinder until the first preset working height is reached, ensuring a smooth start to the lifting action. Subsequently, according to the constant speed control curve, the system controls the target controlled object to run at a constant speed between the first and second preset working heights. This process avoids abrupt speed changes, reducing energy consumption and equipment wear. Finally, the system switches to the deceleration control curve. When the unmanned forklift approaches the expected working height from the second preset working height, the output percentage of the hydraulic cylinder is smoothly reduced to achieve smooth deceleration and precise stopping of the target controlled object, avoiding overshoot or oscillation and improving operational accuracy and safety.

[0116] This application achieves precise and smooth control of the lifting and lowering movements of an unmanned forklift. The embodiments of this application do not rely on complex control algorithms or additional load detection devices; they only require information provided by a height detection unit, combined with a preset control curve, to achieve coordinated control of the fork teeth and mast, ensuring the efficiency and safety of the unmanned forklift in automated operating environments. By implementing a phased control strategy of acceleration, constant speed, and deceleration, the embodiments of this application ensure that the entire process of lifting and lowering the unmanned forklift is smooth and controllable from start to stop, reducing speed abrupt changes and equipment impact caused by improper acceleration and deceleration. This effectively improves the accuracy and efficiency of forklift operations. Simultaneously, this control strategy simplifies the system structure, reduces hardware requirements, and makes the control of the unmanned forklift more intelligent and flexible in complex operating environments, directly improving the forklift's operational capabilities and stability.

[0117] For example, suppose the current total height of the unmanned forklift is 1.5 meters, while the expected working height is 4.5 meters. The system first determines the target lifting direction as upward, and then, based on the acceleration control curve, prioritizes controlling the forks to accelerate upward until the first preset working height is reached. When the forks reach the maximum allowable lifting height (e.g., 3 meters), the system applies the acceleration control curve to the mast until the mast reaches the second preset working height. Next, the system controls the mast to rise at a constant speed from the first preset working height to the second preset working height according to the uniform speed control curve, ensuring stable operation. Finally, when approaching the expected working height of 4.5 meters, the system applies the deceleration control curve to smoothly reduce the mast's rising speed until it accurately stops at the expected working height, achieving high precision and safety in operation.

[0118] By implementing the above control strategy, the embodiments of this application can ensure that the unmanned forklift achieves phased control of smooth acceleration, constant speed operation, and precise deceleration during the lifting process, directly improving the accuracy and efficiency of forklift operation, while reducing equipment impact and protecting the long-term health of the equipment. The flexibility and intelligence of this strategy make it suitable for widespread application in the automated control of unmanned forklifts under different load conditions and operational requirements, requiring no additional sensors or complex algorithms, thus achieving efficient, safe, and economical operation control.

[0119] Figure 2 This is a system block diagram of a forklift height lifting control system according to an embodiment of this application, such as... Figure 2 As shown, Figure 2 The system block diagram shown comprehensively and clearly depicts the composition architecture and information flow path of a forklift height lifting control system, and is the core view for understanding the technical solution of the embodiments of this application. The system mainly consists of three key parts: a height detection unit, a control unit, and a hydraulic cylinder execution unit. Each part achieves precise coordinated control through the interaction of data and signals.

[0120] The height detection unit includes a first wire encoder mounted on the end of the fork teeth and a second wire encoder mounted on the end of the mast. It is used to collect real-time height information of the fork teeth and mast and transmit this data to the control unit for processing. This unit ensures that the system can monitor the forklift's key motion parameters in real time, providing an accurate data foundation for subsequent control actions.

[0121] The control unit is the intelligent core of the system. It receives data input from the height detection unit, generates control signal commands based on the target lifting direction and control logic, and drives the hydraulic cylinder actuator to perform lifting control. The control unit has both automatic and manual modes, which can automatically switch according to external input, and executes a height control strategy based on a trapezoidal acceleration and deceleration algorithm to ensure the smoothness and precision of the forklift lifting process. In addition, the control unit is also responsible for initializing system parameters, including but not limited to maximum and minimum height limits, acceleration, and deceleration, to adapt to different operational needs and working conditions.

[0122] The hydraulic cylinder actuator unit includes a fork cylinder and a mast cylinder. As the system's actuator, it is responsible for converting the percentage control signal output from the control unit into actual lifting actions, thus achieving physical control of the fork and mast. This unit ensures the controllability and high precision of the lifting action by precisely controlling the cylinder output, making it a key component for achieving automated lifting in the system.

[0123] The overall system block diagram demonstrates the tight integration and information loop between height detection, intelligent control, and actuators, ensuring high efficiency and safety of unmanned forklifts in automated operations. Through this system structure design, the embodiments of this application can achieve intelligent decision-making and precise execution of forklift lifting operations. Without additional sensors or complex control algorithms, it can achieve smooth and coordinated lifting of the forks and mast under different load conditions, improving the operational accuracy of unmanned forklifts in complex working conditions and extending the lifespan of equipment components.

[0124] The height detection unit consists of a first wire encoder (for fork tooth height detection) and a second wire encoder (for mast height detection). It collects real-time vertical displacement information of the fork teeth and mast, providing it to the control unit for calculation and analysis. The control unit receives the height information and, based on preset control logic and algorithms, determines the lifting direction, selects the target control object, generates cylinder control signals, and switches modes as needed. It is the core of automated control. The cylinder execution unit includes fork tooth cylinders and mast cylinders, responsible for executing the actual lifting actions according to the control unit's instructions, converting electrical signals into equipment drives to achieve forklift height adjustment.

[0125] pass Figure 2The system design of this application enables coordinated lifting control of the mast and forks of an unmanned forklift during automated operation. This not only improves the accuracy and efficiency of forklift operations but also significantly enhances the smoothness of movement and the lifespan of equipment components through trapezoidal acceleration / deceleration algorithms and adaptive height control logic. This design avoids the complexity of controlling based solely on load, simplifies the control process, and ensures smooth and precise lifting movements for the forklift under both no-load and heavy-load conditions. This directly leads to improved operational accuracy and stability, and reduces energy waste and equipment wear during forklift operation.

[0126] This application addresses the problems of poor motion coordination, insufficient load adaptability, complex structure, low positioning accuracy, and lag in control response of existing forklift lifting control systems. The present invention provides a forklift height lifting control method. This system achieves automatic coordinated lifting control of the forks and mast through the collaboration of a height detection unit and a control algorithm. A trapezoidal acceleration / deceleration algorithm is used to smoothly adjust the cylinder output, and the lifting rhythm is dynamically adjusted according to the real-time height difference, achieving smooth and precise control under both no-load and heavy-load conditions, avoiding sudden movements, overshoot, and shocks.

[0127] This application achieves automatic hierarchical linkage and smooth switching between the fork and the gantry through the synergy of height detection and control algorithms, significantly improving the coordination of lifting actions and equipment lifespan. It can adaptively adjust the cylinder output based solely on height sensor data, eliminating the need for additional load detection devices, reducing system complexity and improving versatility. At the same time, it employs a trapezoidal acceleration and deceleration algorithm to smoothly control the cylinder output, effectively reducing overshoot and oscillation, enabling the fork and gantry to stop smoothly when approaching the target height, achieving high-precision positioning and stable lifting.

[0128] This application also provides a forklift height lifting control system, including a height detection unit, a control unit, and a hydraulic cylinder execution unit. The height detection unit is used to collect real-time information on the fork tooth height Hf and the mast height Hm. The fork tooth height is obtained by a wire encoder installed at the end of the fork tooth, and the mast height is obtained by a wire encoder Hmast installed at the end of the mast and subtracted from the fork tooth height Hm = Hmast - Hf, thereby achieving precise height control of the mast relative to the fork tooth. The hydraulic cylinder execution unit is used to convert the hydraulic cylinder percentage signal output by the control unit into the actual lifting speed. When the percentage is 100%, the lifting is performed at the rated speed, and when the percentage is 0, the lifting stops. It strictly corresponds to the percentage signal issued by the control unit to achieve predictable and precise lifting motion control.

[0129] The control unit is used to initialize and set parameters such as the maximum / minimum height of the fork and mast, the lifting acceleration, and the minimum hydraulic cylinder control percentage. It differentiates between manual and automatic modes based on real-time height information and external input. In manual mode, upon receiving an upward command, the fork is driven to its maximum height before the mast rises; upon receiving a downward command, the mast is driven to its minimum height before the fork descends. In automatic mode, the lifting direction is determined based on the difference between the target height and the current total height. The fork is controlled to move within its adjustable range until its limit position is reached, at which point the mast is controlled to move, achieving coordinated lifting. Through dynamic adjustment of the hydraulic cylinder percentage trapezoidal acceleration, smooth coordinated lifting and precise height control of the fork and mast are achieved, ensuring stable operation and positioning accuracy under both no-load and loaded conditions without the need for load measurement.

[0130] After system initialization, the control unit needs to set a series of key parameters, including: the maximum and minimum heights of the fork and gantry, and the acceleration during ascent and descent. The parameters include deceleration β, effective height difference threshold ΔHeff, effective minimum height difference ΔHstable, stop threshold Hstop, and end-deceleration threshold distance Ddec. These parameters define the system's dynamic response characteristics and safety boundaries, ensuring smooth start-stop and precise positioning under different load conditions. The control unit collects real-time data on the fork height Hf and gantry height Hm through the height detection unit and executes different control logics according to the external input control mode (automatic or manual mode).

[0131] In automatic control mode, the control unit compares the set target height with the real-time detected total height of the gantry and fork, automatically correcting any targets exceeding the maximum height to the maximum value and those below zero to zero. The control unit calculates the difference between the current total height and the target height in real time. When the height error is less than a set threshold, it determines that the lifting is complete and stops outputting. When the height difference is positive, it executes upward control; when the height difference is negative, it executes downward control. Before the action is executed, the control unit automatically resets the motion flags of the gantry and fork based on the height status information to ensure the integrity and safety of the control logic, achieving coordinated control and precise positioning of the gantry and fork.

[0132] When the control unit performs lifting control in automatic mode, it automatically determines the object to be lifted based on the difference between the current total height and the target height. When the target height is within the adjustable range of the fork, simply driving the fork upwards is sufficient to complete the height adjustment. When the fork has risen to its maximum height but the target height has not yet been reached, only the mast is driven upwards to complete the margin compensation. When a single object is being lifted, the cylinder output percentage gradually increases from zero according to the set acceleration, forming a trapezoidal acceleration curve. When the height change within a continuous sampling period reaches the effective height difference threshold, the current cylinder output percentage is kept constant and does not increase further. When it is detected that the current height is close to the target height... When the height is reached, it enters the deceleration zone and gradually reduces the output percentage according to the set trapezoidal deceleration to achieve a smooth stop. When it is necessary to lift the fork and the mast at the same time, the control unit first drives the fork to rise to its maximum allowable height. Then the mast continues to rise using the current cylinder output percentage of the fork, without the need for re-acceleration, so as to ensure the continuity and smoothness of the movement. When the current height reaches the preset stop threshold or an overshoot exceeding the allowable error is detected, the control unit immediately stops the cylinder output and locks the execution position to prevent the fork from failing to stop in time or from continuously overshooting, thereby achieving safe, smooth and high-precision coordinated lifting control of the mast and the fork.

[0133] When the control unit performs descent control in automatic mode, it automatically determines the object to be lifted based on the difference between the current total height and the target height: when the target height is within the adjustable range of the fork, only the fork is driven to rise; when the fork has reached its maximum height and the target height has not yet been reached, only the mast is driven for compensation; when a single object is rising, the cylinder output percentage increases from zero according to the set acceleration to form a trapezoidal acceleration curve; when the height change reaches the effective threshold, the output is maintained; when approaching the target height, it stops smoothly according to the set trapezoidal deceleration; if it is necessary to lift the fork and the mast simultaneously, the control unit first drives the fork to the maximum height, and then the mast continues to rise using the current output of the fork, without the need for re-acceleration, ensuring continuous and smooth action; when the height reaches the preset stop threshold or overshoot occurs, the cylinder output is immediately stopped and the position is locked, realizing safe, stable, and high-precision coordinated rising of the mast and the fork.

[0134] The control unit employs a trapezoidal acceleration / deceleration control strategy during ascent or descent, using the cylinder percentage as the control variable to form a segmented control model consisting of an acceleration phase, a constant speed phase, and a deceleration phase. During the acceleration phase, when the cylinder begins to move, the output cylinder percentage C(t) gradually increases from zero according to the set acceleration α, as expressed by the following formula:

[0135] C(t+△t)=C(t)+α△t,C(t)≤Cmax;

[0136] Where △t is the control cycle and Cmax is the maximum percentage of cylinder output.

[0137] During the constant-speed phase, when the height change within a continuous sampling period reaches the set effective height difference threshold ΔHeff, the output percentage remains constant, as expressed by the following formula:

[0138] C(t) = Cconst, when ΔHsample ≥ ΔHeff;

[0139] During the deceleration phase, when the difference between the current height and the target height, |HcurrentHtarget|, is less than the set threshold distance Ddec, the deceleration control phase begins. The output percentage decreases by the cylinder output percentage according to the set deceleration rate β. Simultaneously, it is determined in real time whether the change in the height difference between the previous and next steps within a continuous sampling period is less than the set threshold ΔHstable, which is expressed by the following formula:

[0140] C(t+Δt)=C(t)βΔt, when ΔHsample≥ΔHstable;

[0141] When ΔHsample < ΔHstable, the hydraulic cylinder maintains the current percentage while decelerating until the stopping condition is met.

[0142] The stopping condition is that when the height reaches the preset stopping threshold Hstop, or when the overshoot exceeds the threshold |HcurrentHtarget|>Hstop, the cylinder output is immediately stopped to prevent overshoot and oscillation.

[0143] This trapezoidal acceleration and deceleration control mechanism is suitable for independent control of the fork or gantry, as well as the synchronous control process when the two are lifting and lowering together. It can achieve smooth start and stop, speed self-adaptation, and precise height positioning.

[0144] In manual control mode, the control unit automatically controls the lifting and lowering of the fork and gantry according to operation commands, without relying on the cylinder percentage signal output by the remote control. Specifically, upon receiving an upward command, the control unit prioritizes driving the fork upward. The gantry remains stationary until the fork reaches its maximum or target height. Once the fork reaches its lifting limit, the control unit then drives the gantry to its maximum or target height, gradually increasing the cylinder output percentage according to a preset acceleration to achieve a smooth lift. Similarly, upon receiving a downward command, the control unit prioritizes driving the gantry downward. The fork remains stationary until the gantry reaches its minimum or target height. Once the gantry reaches its lowering limit, the control unit then drives the fork downward to its minimum or target height, gradually increasing the cylinder output percentage according to a preset acceleration to achieve a smooth descent. Throughout the lifting and lowering process, the control unit monitors the height changes of the fork and gantry in real time. If any height reaches a preset stop threshold or overshoot exceeds the allowable range, the corresponding cylinder output is immediately stopped to prevent overshoot and unstable stopping.

[0145] In manual control mode, the system's ascent and descent processes follow the maximum and minimum height limits of the fork and gantry, ensuring that the movement does not exceed the allowable range of the equipment structure. Through the above logic control, the system can achieve smooth coordinated movement of the fork and gantry under both no-load and loaded conditions, effectively preventing abnormal lifting speeds caused by manual operation and improving operational safety and height control accuracy.

[0146] The system includes a height detection unit for real-time acquisition of the height information of the fork teeth and the gantry. The height detection unit includes a first wire encoder mounted on the end of the fork teeth and a second wire encoder mounted on the end of the gantry. The first wire encoder detects the lifting height Hf of the fork teeth relative to their initial position, and the second wire encoder detects the height Hmast of the gantry end relative to its initial position. The control unit calculates the relative height difference Hm of the gantry relative to the end of the fork teeth based on the detected values, satisfying the following formula:

[0147] Hm = HmastHf;

[0148] The gantry height Hm is the relative height difference between the end of the gantry and the end of the fork, rather than the actual height of the gantry above the ground. This relative height difference is used to control the lifting amount of the gantry relative to the fork, so as to realize the coordinated movement and precise height control between the gantry and the fork.

[0149] The system includes a hydraulic cylinder actuator unit for performing actual lifting and lowering actions based on the hydraulic cylinder percentage control signal output by the control unit. The hydraulic cylinder actuator unit includes a fork cylinder and a gantry cylinder. After receiving the percentage control signal from the control unit, the fork cylinder drives the fork to lift and lower according to the corresponding ratio. When the cylinder control value is 100, the fork lifts and lowers at the rated speed; when the cylinder control value is 0, the fork remains stationary. Similarly, after receiving the percentage control signal from the control unit, the gantry cylinder drives the gantry to lift and lower according to the corresponding ratio. When the cylinder control value is 100, the gantry lifts and lowers at the rated speed; when the cylinder control value is 0, the gantry remains stationary. The control signal range for both the fork cylinder and the gantry cylinder is 0 to 100, corresponding to a linear output range from stop to rated speed. The hydraulic cylinder actuator unit only acts as an actuator and does not participate in load compensation or acceleration / deceleration calculations. Its actual lifting and lowering speed corresponds one-to-one with the control value output by the control unit, thereby achieving predictability and high-precision control of the lifting and lowering actions.

[0150] In this application, the system prioritizes driving the fork teeth to the adjustable limit position during ascent, and then uses the current output of the fork teeth to drive the gantry to rise and fall; during descent, it first drives the gantry to the lowest point, and then uses the gantry output to drive the fork teeth to fall. It can determine that only a single unit action is needed to complete the height adjustment, avoiding unnecessary actions and ensuring a continuous, smooth, and precise lifting process. At the start of lifting, the cylinder output increases from zero according to the set acceleration, remains constant after reaching the effective height difference, and decreases in a trapezoidal deceleration until it stops when approaching the target height. This mechanism can automatically adjust the acceleration and deceleration process according to no-load or loaded conditions without measuring the load, achieving high smoothness, high precision, and strong adaptability in lifting.

[0151] According to an embodiment of the present invention, a device embodiment of a forklift height lifting control device is provided. It should be noted that the device can be used to execute the above-described forklift height lifting control method. Figure 3 This is a schematic diagram of a forklift height lifting control device according to an embodiment of this application, as shown below. Figure 3 As shown, the device includes: an acquisition module 302, a first determination module 304, a second determination module 306, and a control module 308.

[0152] The acquisition module is used to acquire the first height of the fork tines, the second height of the mast, and the total height of the tines and mast. The tines are the structure on the forklift used to carry objects, and the mast is the structure on the forklift used to connect the tines. The first height represents the height of the tines relative to a first initial position, the second height represents the height of the mast relative to a second initial position, and the total height represents the overall height of the tines and mast. The first initial position is the lowest position the tines move on the forklift, and the second initial position is the lowest position the mast moves on the forklift. The first determination module is used to determine the height of the fork tines based on the first initial position. The system comprises a first height and a second height, which determine the target height difference between the fork tines and the mast, wherein the target height difference represents the height difference between the mast and the fork tines; a second determining module is used to determine the target lifting direction and the target control object based on the forklift's expected operating height and total height, wherein the target control object includes at least one of the following: fork tines, mast, and the expected operating height represents the total height that the fork tines and mast need to reach when the forklift is operating; and a control module is used to perform lifting control on the target control object based on the target height difference and total height, and based on the target lifting direction, so that the forklift reaches the expected operating height.

[0153] Optionally, the first determining module is used to determine the target lifting direction based on the expected working height and the total height; and to determine the target control object based on the first lifting state of the fork, the second lifting state of the gantry and the target lifting direction, wherein the first lifting state is used to indicate whether to perform a lifting operation on the fork, and the second lifting state is used to indicate whether to perform a lifting operation on the gantry.

[0154] Optionally, the first determining module is used to determine the target lifting direction as an upward direction if the total height is less than the expected working height, and to determine the target lifting direction as a downward direction if the total height is greater than the expected working height.

[0155] Optionally, the second determining module is used to determine whether the fork tooth has reached its maximum lifting height based on the first lifting state if the target lifting direction is upward; if the fork tooth has not reached its maximum lifting height, and the maximum lifting height is greater than or equal to the expected working height, the target control object is determined to be the fork tooth; if the fork tooth has not reached its maximum lifting height, and the maximum lifting height is less than the expected working height, the target control object is determined to be the fork tooth and the gantry; if the fork tooth reaches its maximum lifting height, the target control object is determined to be the gantry.

[0156] Optionally, the second determining module is used to determine whether the gantry has reached its maximum descent height based on the second lifting state if the target lifting direction is the descent direction; if the gantry has not reached its maximum descent height and the maximum descent height is less than or equal to the expected working height, the target control object is determined to be the gantry; if the gantry has not reached its maximum descent height and the maximum descent height is greater than the expected working height, the target control object is determined to be the fork and the gantry; if the gantry has reached its maximum descent height, the target control object is determined to be the fork.

[0157] Optionally, the control module is used to determine multiple control curves based on the target height difference and the total height, wherein different control curves correspond to different accelerations; based on the target lifting direction, the target controlled object is controlled sequentially according to the multiple control curves so that the forklift reaches the expected working height.

[0158] Optionally, the control module is used to accelerate the target controlled object according to the acceleration control curve based on the target lifting direction, so that the forklift reaches a first preset working height, wherein the first preset working height is the working height to be reached by the target controlled object during the acceleration control phase; to perform uniform speed control on the target controlled object according to the uniform speed control curve based on the target lifting direction, so that the forklift reaches a second preset working height from the first preset working height, wherein the second preset working height is the working height to be reached by the target controlled object during the uniform speed control phase; and to perform deceleration control on the target controlled object according to the deceleration control curve based on the target lifting direction, so that the forklift reaches the expected working height from the second preset working height.

[0159] Embodiments of this application also provide an electronic device, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods in various embodiments of the present invention during runtime.

[0160] Embodiments of this application also provide a computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of the present invention.

[0161] Embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements the methods of various embodiments of the present invention.

[0162] Embodiments of this application also provide a computer program product, including a non-volatile computer-readable storage medium for storing a computer program that, when executed by a processor, implements the methods in various embodiments of the present invention.

[0163] Embodiments of this application also provide a computer program that, when executed by a processor, implements the methods described in the various embodiments of the present invention.

[0164] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0165] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0166] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0167] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0168] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0169] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A forklift height lifting control method, characterized in that, include: The method obtains a first height of the fork tines, a second height of the mast on the forklift, and a total height of the fork tines and the mast, wherein the fork tines are structures on the forklift used to carry objects, the mast is a structure on the forklift used to connect the fork tines, the first height represents the height of the fork tines relative to a first initial position, the second height represents the height of the mast relative to a second initial position, and the total height represents the overall height of the fork tines and the mast, wherein the first initial position is the lowest position the fork tines have moved on the forklift, and the second initial position is the lowest position the mast has moved on the forklift. Based on the first height and the second height, a target height difference between the fork tooth and the gantry is determined, wherein the target height difference is used to represent the height difference of the gantry relative to the fork tooth; Based on the expected working height and the total height of the forklift, the target lifting direction and the target control object are determined, wherein the target control object includes at least one of the following: fork teeth, mast, and the expected working height is used to represent the total height that the fork teeth and the mast need to reach when the forklift is operating; Based on the target height difference and the total height, the target controlled object is raised or lowered according to the target lifting direction so that the forklift reaches the expected working height.

2. The method according to claim 1, characterized in that, Based on the expected operating height of the forklift and the total height, the target lifting direction and the target control object are determined, including: The target lifting direction is determined based on the expected working height and the total height; The target control object is determined based on the first lifting state of the fork, the second lifting state of the gantry, and the target lifting direction, wherein the first lifting state indicates whether to lift the fork and the second lifting state indicates whether to lift the gantry.

3. The method according to claim 2, characterized in that, Determining the target lifting direction based on the expected working height and the total height includes: If the total height is less than the expected working height, the target lifting direction is determined to be the upward direction; If the total height is greater than the expected working height, the target lifting direction is determined to be the descent direction.

4. The method according to claim 2, characterized in that, Based on the first lifting state of the fork teeth, the second lifting state of the gantry, and the target lifting direction, the target control object is determined, including: If the target lifting direction is upward, determine whether the fork tooth has reached the maximum lifting height of the fork tooth based on the first lifting state; If the fork tooth does not reach the maximum lifting height, and the maximum lifting height is greater than or equal to the expected working height, the target control object is determined to be the fork tooth; If the fork tooth does not reach the maximum lifting height, and the maximum lifting height is less than the expected working height, the target control object is determined to be the fork tooth and the gantry. If the fork reaches the maximum rising height, the target controlled object is determined to be the gantry.

5. The method according to claim 2, characterized in that, Based on the first lifting state of the fork teeth, the second lifting state of the gantry, and the target lifting direction, the target control object is determined, including: If the target lifting direction is a descending direction, determine whether the gantry has reached the maximum descending height of the gantry based on the second lifting state; If the gantry does not reach the maximum descent height, and the maximum descent height is less than or equal to the expected operating height, the target control object is determined to be the gantry. If the gantry does not reach the maximum descent height, and the maximum descent height is greater than the expected working height, the target control object is determined to be the fork and the gantry. If the gantry reaches the maximum descent height, the target control object is determined to be the fork tooth.

6. The method according to claim 1, characterized in that, Based on the target height difference and the total height, and based on the target lifting direction, the target controlled object is subjected to lifting control so that the forklift reaches the expected working height, including: Based on the target height difference and the total height, multiple control curves are determined, wherein different control curves correspond to different accelerations; Based on the target lifting direction, the target controlled object is controlled sequentially according to the multiple control curves so that the forklift reaches the expected working height.

7. The method according to claim 6, characterized in that, The multiple control curves include an acceleration control curve, a constant speed control curve, and a deceleration control curve; based on the target lifting direction, the target controlled object is controlled sequentially according to the multiple control curves to make the forklift reach the expected working height, including: Based on the target lifting direction, the target controlled object is accelerated according to the acceleration control curve so that the forklift reaches a first preset working height, wherein the first preset working height is the working height that the target controlled object is to reach during the acceleration control phase; Based on the target lifting direction, the target controlled object is controlled at a constant speed according to the constant speed control curve, so that the forklift can reach a second preset working height from the first preset working height, wherein the second preset working height is the working height that the target controlled object needs to reach in the constant speed control stage; Based on the target lifting direction, the target controlled object is decelerated according to the deceleration control curve so that the forklift can reach the expected working height from the second preset working height.

8. An electronic device, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the method according to any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored executable program, wherein, when the executable program is executed, it controls the device on which the storage medium is located to perform the method according to any one of claims 1 to 7.

10. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method according to any one of claims 1 to 7.

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