Position control method and system for electric fork truck lifting localization

Abstract

This invention provides a position control method and system for lifting and addressing of an electric forklift, belonging to the field of electric forklift technology. It includes: acquiring the current fork height information and an addressing switch signal; determining whether lifting and addressing is triggered based on the addressing switch signal; if the addressing switch signal is triggered, determining whether the fork is currently within the control area based on the fork height information; if within the control area, determining whether the lifting switch is closed; if the lifting switch is closed, determining whether the fork is within the tolerance area; if the fork is not within the tolerance area, acquiring the target speed of the motor and controlling the fork to continue lifting; after the fork continues to lift, updating the current fork height information and returning to the step of acquiring the current fork height information and the triggering switch signal; if the fork is within the tolerance area, controlling the motor to stop, and the fork lifting and addressing is completed.

Description

Technical Field

[0001] This invention relates to the field of electric forklift technology, and more specifically to a position control method and system for lifting and positioning of an electric forklift. Background Technology

[0002] In forklift operations involving heavy material handling and stacking, lifting and lowering heavy loads is a fundamental function. In practice, materials are typically placed on racks at fixed heights, requiring the forks to frequently lift to specific heights for loading and unloading. To address this, forklifts are equipped with a lifting positioning function, enabling automatic stopping at specific heights to improve work efficiency.

[0003] Currently, the lifting addressing function used on forklifts is only equipped on vehicles with solenoid valves, adjusting the lifting speed or stopping the lifting by controlling the opening of the solenoid valve. This current method relies on controlling the opening of the solenoid valve, and for electric forklifts, the current lifting addressing function cannot be applied to the more common mechanical valve forklifts. Because the valve opening depends on the driver's operation, the state of the hydraulic circuit and the actual lifting status of the goods are difficult to predict accurately; at the same time, the performance of the hydraulic circuit varies under different loads, and without the use of high-cost, high-precision weight sensors, the control algorithm lacks versatility for different working conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a position control method and system for lifting and positioning of electric forklifts. This control method and system solves the problem that non-electromagnetic valve electric forklifts cannot be equipped with lifting and positioning functions. It also solves the problem that the lifting speed is difficult to control and the operation is not comfortable when lifting and positioning is performed under different load weights and different user operating habits. The lifting and positioning function is completed by adjusting the motor speed alone, without the need to add load weight judgment or adjust the motor torque, and has good versatility.

[0005] To achieve the above objectives, embodiments of the present invention provide a position control method for lifting and positioning of an electric forklift, the control method comprising: Obtain the current fork height information and address switch signal; Based on the address recognition switch signal, determine whether to trigger the lifting address recognition; When the address recognition switch signal is triggered, it is determined whether the forks are in the control area at the current moment based on the fork height information; When the area is within the control zone, determine whether the hoisting switch is closed; If the lifting switch is closed, determine whether the forks are in the tolerance zone; If it is determined that the forks are not in the tolerance zone, the target speed of the motor is obtained, and the forks are controlled to continue to rise. After the forks continue to rise, update the current fork height information and return to the steps of obtaining the current fork height information and trigger switch signal; If it is determined that the forks are in the tolerance range, the motor is stopped and the fork lifting address is completed; Determine whether parameter updates are prohibited at the current moment; Without disabling parameter updates, the results are evaluated and parameters are updated based on the current fork stop height. If parameter updates are prohibited, update the current fork height information and end the forklift lifting address recognition.

[0006] Optionally, obtaining the target speed of the motor includes: The current lifting speed of the forks is obtained according to formula (1). (1) in, Indicates in The lifting speed of the forks at all times. A constant, representing altitude data. Update cycle Indicates in The height of the gantry at all times, For time.

[0007] Optionally, obtaining the target speed of the motor includes: The current lifting acceleration of the forks is obtained according to formula (2). (2) in, This represents the current lifting acceleration of the forks.

[0008] Optionally, obtaining the target speed of the motor includes: The target speed of the motor is obtained according to formula (3). (3) (4) in, Indicates in The target speed of the motor at all times, Indicates in At all times The speed proportional parameter at time, The constant represents the minimum allowable speed limit. This represents the ideal lift velocity trajectory function that is correlated with altitude. This is a proportional parameter.

[0009] Optionally, evaluating the results and updating parameters based on the current fork stop height includes: The lifting positioning error value is obtained according to formula (5). (5) in, This is the lifting address error value. This represents the target value for the fork height.

[0010] Optionally, evaluating the results and updating parameters based on the current fork stop height includes: The evaluation results are obtained according to formula (6). (6) in, To evaluate the results, This is the tolerance range value. To control the range value.

[0011] Optionally, evaluating the results and updating parameters based on the current fork stop height includes: The parameters are updated according to formula (7). (7) in, For the updated parameters , To update the rate scaling parameter.

[0012] Optionally, evaluating the results and updating parameters based on the current fork stop height includes: The parameters are updated according to formula (8). (8) in, Indicates the updated parameters , To update the rate scaling parameter.

[0013] On the other hand, the present invention also provides a position control system for lifting and addressing an electric forklift, the control system including a processor for executing the control method as described above.

[0014] Through the above technical solution, the present invention provides a position control method and system for lifting and positioning of electric forklifts. This control method and system solves the problem that non-electromagnetic valve electric forklifts cannot be equipped with lifting and positioning functions, and solves the problem that the lifting speed is difficult to control and the operation is not comfortable when lifting and positioning is performed under different load weights and different user operating habits. The lifting and positioning function is completed by adjusting the motor speed alone, without the need to add load weight judgment or adjust the motor torque, and has good versatility.

[0015] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of a position control method for lifting and addressing an electric forklift, according to one embodiment of the present invention. Figure 2 This is a schematic diagram of the control area according to one embodiment of the present invention; Figure 3 This is a flowchart illustrating the process of obtaining the target speed of a motor according to one embodiment of the present invention; Figure 4 This is a flowchart illustrating the result evaluation and parameter update process of one embodiment of the present invention. Detailed Implementation

[0017] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0018] In the embodiments of this application, certain software, components, models and other existing solutions in the industry may be mentioned. These should be regarded as exemplary and are only intended to illustrate the feasibility of implementing the technical solution of this application. However, they do not mean that the applicant has used or necessarily used the solution.

[0019] like Figure 1 The diagram shown is a flowchart of a position control method for lifting and positioning an electric forklift, according to one embodiment of the present invention. Figure 1 In this context, the control method may include: In step S1, the current fork height information and address switch signal are obtained; In step S2, it is determined whether the lifting address is triggered based on the address recognition switch signal; In step S3, when the address recognition switch signal is triggered, it is determined whether the forks are in the control area at the current moment based on the fork height information; In step S4, if the area is within the control zone, it is determined whether the hoisting switch is closed; In step S5, if the lifting switch is closed, it is determined whether the forks are in the tolerance zone; In step S6, if it is determined that the forks are not in the tolerance zone, the target speed of the motor is obtained, and the forks are controlled to continue to rise. In step S7, after the forks continue to rise, the current fork height information is updated, and the process returns to the step of obtaining the current fork height information and the trigger switch signal. In step S8, if it is determined that the forks are in the tolerance zone, the motor is stopped and the fork lifting address is completed; In step S9, it is determined whether parameter updates are prohibited at the current moment; In step S10, without disabling parameter updates, the result is evaluated and the parameters are updated based on the current fork stop height. In step S11, if parameter updates are prohibited, update the fork height information at the current moment and end the forklift lifting address recognition.

[0020] In Figure 1 In the method shown, step S1 can be used to obtain the current fork height information and the addressing switch signal. Step S2 determines whether the current addressing switch signal triggers lifting addressing. If the addressing switch is not triggered, step S12 is performed to update the current fork height information. If the addressing switch is triggered, step S3 is performed to determine whether the forks are currently within the control area based on the fork height information. A schematic diagram of the control area can be shown below. Figure 2 As shown. If not within the control zone, the current fork height information is updated, and the process returns to the step of obtaining the current fork height information and the trigger switch signal. If within the control zone, step S4 is performed to determine if the lifting switch is closed. If the lifting switch is not closed, step S14 is performed to set the current data and disable parameter updates, update the current fork height information, and return to the step of obtaining the current fork height information and the trigger switch signal. If the lifting switch is closed, the forks continue to rise, and step S5 is performed to determine if the forks are within the tolerance zone. If it is determined that the train is not within the tolerance zone, the target speed of the motor is obtained according to S6, and the forks are controlled to continue rising. The specific method for obtaining the target speed of the motor can be of various forms known to those skilled in the art. In one example of the present invention, the method for obtaining the target speed of the motor can be as follows: Figure 3 The steps shown are in this Figure 3 The process may further include the following steps: In step S11, the current lifting speed of the forks is obtained according to formula (1). (1) in, Indicates in The lifting speed of the forks at all times. A constant, representing altitude data. Update cycle Indicates in The height of the gantry at all times, For time.

[0021] In step S12, the current lifting acceleration of the forks is obtained according to formula (2). (2) in, This represents the current lifting acceleration of the forks.

[0022] In step S13, the target speed of the motor is obtained according to formula (3). (3) (4) in, Indicates in The target speed of the motor at all times, Indicates in At all times The speed proportional parameter at time, The constant represents the minimum allowable speed limit. This represents the ideal lift velocity trajectory function that is correlated with altitude. This is a proportional parameter.

[0023] Step S7 can be used to update the current fork height information after the forks continue to rise, and return to the step of obtaining the current fork height information and the trigger switch signal. If it is determined that the forks are in the tolerance range, the motor is stopped according to step S8, and the fork lifting address is completed. According to step S9, it is determined whether parameter updates are prohibited at the current moment. If parameter updates are not prohibited, in step S10, result evaluation and parameter updates are performed based on the current fork stop height. The specific methods for result evaluation and parameter updates can be various forms known to those skilled in the art. In one example of the present invention, the specific method for result evaluation and parameter updates can be as follows: Figure 4 The steps shown are in this Figure 4 The process may further include the following steps: In step S21, the lifting addressing error value is obtained according to formula (5). (5) in, This is the lifting address error value. This represents the target value for the fork height.

[0024] In step S22, the evaluation result is obtained according to formula (6). (6) in, To evaluate the results, This is the tolerance range value. To control the range value.

[0025] In step S23, the parameters are updated according to formula (7). (7) in, For the updated parameters , To update the rate scaling parameter.

[0026] In step S24, the parameters are updated according to formula (8). (8) in, Indicates the updated parameters , The update rate ratio parameter is used to determine the number of updates required. However, setting the parameter too high can cause the optimal point to be missed.

[0027] Step S11 can be used to update the fork height information at the current moment and end the forklift lifting address recognition when parameter updates are prohibited.

[0028] On the other hand, the present invention also provides a position control system for lifting and addressing an electric forklift, the control system including a processor for executing the control method as described above.

[0029] Through the above technical solution, the present invention provides a position control method and system for lifting and positioning of electric forklifts. This control method and system solves the problem that non-electromagnetic valve electric forklifts cannot be equipped with lifting and positioning functions, and solves the problem that the lifting speed is difficult to control and the operation is not comfortable when lifting and positioning is performed under different load weights and different user operating habits. The lifting and positioning function is completed by adjusting the motor speed alone, without the need to add load weight judgment or adjust the motor torque, and has good versatility.

[0030] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0031] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0032] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0033] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0034] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0035] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0036] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0037] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0038] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A position control method for lifting and positioning of an electric forklift, characterized in that, The control method includes: Obtain the current fork height information and address switch signal; Based on the address recognition switch signal, determine whether to trigger the lifting address recognition; When the address recognition switch signal is triggered, it is determined whether the forks are in the control area at the current moment based on the fork height information; When the area is within the control zone, determine whether the hoisting switch is closed; If the lifting switch is closed, determine whether the forks are in the tolerance zone; If it is determined that the forks are not in the tolerance zone, the target speed of the motor is obtained, and the forks are controlled to continue to rise. After the forks continue to rise, update the current fork height information and return to the steps of obtaining the current fork height information and trigger switch signal; If it is determined that the forks are in the tolerance range, the motor is stopped and the fork lifting address is completed; Determine whether parameter updates are prohibited at the current moment; Without disabling parameter updates, the results are evaluated and parameters are updated based on the current fork stop height. If parameter updates are prohibited, update the current fork height information and end the forklift lifting address recognition. Obtaining the target speed of the motor includes: The target speed of the motor is obtained according to formula (3). ，（3） ，（4） in, Indicates in The target speed of the motor at all times, Indicates in At all times The speed proportional parameter at time, The constant represents the minimum allowable speed limit. This represents the ideal lift velocity trajectory function that is correlated with altitude. For proportional parameters, Indicates in The lifting speed of the forks at all times. Indicates in The height of the gantry at all times, For time; The evaluation and parameter updates based on the current fork stop height include: The lifting positioning error value is obtained according to formula (5). ，（5） in, This is the lifting address error value. This is the target value for the fork height.

2. The control method according to claim 1, characterized in that, Obtaining the target speed of the motor includes: The current lifting speed of the forks is obtained according to formula (1). ，（1） in, A constant, representing altitude data. The update cycle.

3. The control method according to claim 2, characterized in that, Obtaining the target speed of the motor includes: The current lifting acceleration of the forks is obtained according to formula (2). ，（2） in, This represents the current lifting acceleration of the forks.

4. The control method according to claim 3, characterized in that, The evaluation and parameter updates based on the current fork stop height include: The evaluation results are obtained according to formula (6). ，（6） in, To evaluate the results, This is the tolerance range value. To control the range value.

5. The control method according to claim 4, characterized in that, The evaluation and parameter updates based on the current fork stop height include: The parameters are updated according to formula (7). ，（7） in, For the updated parameters , This is for updating the rate scaling parameter.

6. The control method according to claim 5, characterized in that, The evaluation and parameter updates based on the current fork stop height include: The parameters are updated according to formula (8). ，（8） in, Indicates the updated parameters , This is for updating the rate scaling parameter.

7. A position control system for lifting and positioning of an electric forklift, characterized in that, The control system includes a processor for executing the control method as described in any one of claims 1 to 6.

Images