A stability control method and device for high-position operation of an unmanned forklift

Abstract

The application discloses a kind of unmanned forklift high-position operation stability control method and device, it is related to unmanned forklift technical field.The method comprises: obtaining operating parameter to judge whether to enter high-position operation mode;When entering, the side support mechanism of the both sides of vehicle body is controlled to be expanded to support wheel ground contact synchronously, so that unmanned forklift is changed from three-point support to five support point support;The length of two sides is independently adjusted to make support wheel adhere to ground with preset ground contact pressure;Lifting and / or side shift operation is executed in the state of keeping extension;After operation is completed, the side support mechanism is controlled to be folded in synchronously.The device comprises side support mechanism, hydraulic control system and controller symmetrically installed on the both sides of vehicle body.The application significantly improves the longitudinal stability of unmanned forklift during high-position operation by increasing adaptive side support, prevents overturning, and the support mechanism can be folded without affecting traffic, compatible with passability and stability.

Description

Technical Field

[0001] This application relates to the field of unmanned forklift technology, and in particular to a method and device for controlling the stability of unmanned forklifts in high-position operations. Background Technology

[0002] As a core piece of equipment in automated warehousing and logistics systems, unmanned forklifts are widely used in workshops, warehouses, and other scenarios, undertaking tasks such as cargo handling and stacking. In high-level operations such as high-level stacking and high-level picking, the forks of unmanned forklifts are lifted to a high height, causing their center of gravity to shift significantly upwards and their overall longitudinal stability to decrease significantly. This is one of the core pain points faced by existing unmanned forklifts in high-level operations.

[0003] Current automated forklifts typically employ a three-point support structure (one drive wheel and two load wheels). While this structure offers acceptable stability during low-level operations, its longitudinal support rigidity is insufficient during high-level lifting operations. Uneven ground, uneven loading, or slight swaying of the cargo during operation can easily cause the forklift's center of gravity to shift longitudinally, leading to tip-over accidents. This not only damages the cargo and causes equipment malfunctions but can also affect operational efficiency and even pose safety hazards to personnel. Currently, there are limited measures to improve the stability of automated forklifts during high-level operations. Some solutions only reduce the risk of tip-over by limiting the lifting height or operating speed, but this approach significantly restricts the operating range and efficiency of automated forklifts. Summary of the Invention

[0004] This application provides a method and device for controlling the stability of unmanned forklifts in high-position operations, in order to solve the technical problem in the prior art that unmanned forklifts have insufficient longitudinal stability and are prone to tipping over when lifted to a high position.

[0005] The technical solution adopted in this application is as follows: Firstly, this application provides a method for controlling the stability of unmanned forklifts operating at high positions, including: Obtain the operating parameters of the unmanned forklift, and determine whether the unmanned forklift has entered the high-position operation mode based on the operating parameters; When it is determined that the unmanned forklift has entered the high-level operation mode, the side support mechanisms installed on the left and right sides of the unmanned forklift body are controlled to extend outward synchronously until the support wheels at the end of each side support mechanism are in contact with the ground, so that the unmanned forklift changes from the original three-point support state to a five-point support state including the two side support wheels. The extension length of the left and right side support mechanisms can be adjusted independently to ensure that the left and right support wheels are in contact with the ground with a preset grounding pressure. With the left and right side support mechanisms extended, control the forks of the unmanned forklift to perform lifting and / or lateral movement operations; Once the high-level operation is completed, the left and right side support mechanisms are controlled to retract inward simultaneously, allowing the unmanned forklift to return to normal driving status.

[0006] Furthermore, the criteria for determining whether the unmanned forklift has entered the high-level operation mode include at least one of the following: the fork lifting height reaches or exceeds a preset height threshold, a high-level operation command is received from an external control system, or the unmanned forklift is determined to have entered a preset high-level operation area based on navigation and positioning information.

[0007] Furthermore, as the side support mechanisms on the left and right sides of the unmanned forklift body unfold outward, the unmanned forklift maintains its forward and backward driving functions, and the rolling axis direction of the support wheel is perpendicular to the forward and backward direction of the unmanned forklift, so that the support wheel rolls along the forward and backward direction of the unmanned forklift.

[0008] Furthermore, the independent adjustment of the extension length of the left and right side support mechanisms, so that both left and right support wheels are in contact with the ground with a preset grounding pressure, includes: The oil inlet and return volumes of the hydraulic cylinders in the left and right side support mechanisms are controlled by electromagnetic multi-way valves respectively. Real-time monitoring of the hydraulic cylinder pressure on both the left and right sides; Adjust the extension length of the left and right cylinders respectively until the cylinder pressure of both cylinders reaches the preset ground pressure threshold.

[0009] Furthermore, with the left and right side support mechanisms in the extended state, the unmanned forklift is allowed to move forward and backward at a speed limit lower than the normal driving speed, wherein the speed limit is a preset value or determined in real time according to the lifting height of the forks.

[0010] Secondly, this application provides a stability control device for high-level operation of an unmanned forklift, comprising: The side support mechanism is provided in two sets, which are symmetrically installed on the left and right sides of the unmanned forklift body. Each side support mechanism includes a fixed support A, a fixed support B, a hydraulic cylinder (3), a side support leg and a support wheel. Wherein, the fixed support A and the fixed support B are respectively fixedly connected to preset positions on the side of the unmanned forklift vehicle body; The cylinder body end of the hydraulic cylinder is hinged to the fixed support A, and the piston rod end of the hydraulic cylinder is hinged to the side support leg. The side support leg is hinged to the fixed support B, allowing the side support leg to swing around the hinge axis in the horizontal plane. The support wheel is rotatably connected to the end of the side support leg, and the rotation axis of the support wheel is perpendicular to the forward and backward direction of the unmanned forklift. The hydraulic control system is connected to the cylinders in each of the side support mechanisms and is used to independently control the extension and retraction of each cylinder. The controller, electrically connected to the hydraulic control system, is used to control the side support mechanism to switch between a retracted state and a supported state according to the working state of the unmanned forklift.

[0011] Furthermore, in each of the side support mechanisms, the central axis of the hydraulic cylinder and the rotational centripetal line of the side support leg always remain non-collinear during the swinging process of the side support leg.

[0012] Furthermore, the rolling direction of the support wheel is consistent with the forward and backward direction of the unmanned forklift, so that the support wheel can roll along with the forward or backward movement of the unmanned forklift when it contacts the ground.

[0013] Furthermore, the hydraulic control system includes: The hydraulic pump station is connected to the power system of the unmanned forklift and is used to provide hydraulic power. The electromagnetic multi-way valve assembly has an inlet port connected to the outlet port of the hydraulic pump station and an outlet port connected to the return port of the hydraulic pump station. The electromagnetic multi-way valve assembly has multiple working ports, which are respectively connected to the cylinders in the left and right side support mechanisms, and are used to control the extension and retraction of each cylinder.

[0014] Furthermore, the controller includes: The status detection module is connected to the on-board sensor signals of the unmanned forklift to obtain the operating parameters of the unmanned forklift and determine whether it has entered the high-position operation mode. An extension control module is connected to the hydraulic control system signal and is used to control the support mechanisms on each side to extend outward synchronously when the high-level operation mode is determined to be entered. The grounding adjustment module is connected to the hydraulic control system and is used to adjust the extension length of the left and right cylinders respectively, so that the left and right support wheels are in contact with the ground with a preset grounding pressure. The retraction control module is connected to the hydraulic control system and is used to control the support mechanisms on each side to retract inward synchronously after the completion of the high-level operation.

[0015] Furthermore, the fixed support A and the fixed support B are fixedly connected to the unmanned forklift vehicle body by bolts or welding.

[0016] Furthermore, in each of the aforementioned side support mechanisms: The cylinder body end of the hydraulic cylinder is hinged to the fixed support A via a pin A; The piston rod end of the hydraulic cylinder is hinged to the side support leg via a pin C; The side support leg is hinged to the fixed support B via pin D; The support wheel is rotatably connected to the end of the side support leg via pin B.

[0017] Furthermore, wear-resistant copper sleeves and axial limiting snap rings are respectively provided between the pin A, the pin B, the pin C and the pin D and the corresponding connecting holes.

[0018] Furthermore, the side support mechanism has a retracted state and a supported state: In the retracted state, the side support legs and the support wheels are retracted into the unmanned forklift vehicle. On both sides of the body, the projection of the side support mechanism in the horizontal direction does not exceed the width range of the unmanned forklift body; In the supported state, the support wheels on both the left and right sides simultaneously contact the ground, forming additional support points on the left and right sides of the unmanned forklift body, thus creating a five-support-point support structure for the unmanned forklift.

[0019] Thirdly, this application provides an unmanned forklift, comprising: Forklift body; The device described in the second aspect or any of the possible implementations of the second aspect is wherein the controller of the unmanned forklift high-position operation stability control device is communicatively connected to the vehicle controller of the forklift body.

[0020] The beneficial effects of the second and third aspects described above can be referenced to the first aspect or any possible implementation thereof, and will not be elaborated upon here. Based on the implementations provided in the above aspects, this application can also be further combined to provide more implementations.

[0021] Other advantages, objectives and features of this application will be partly apparent from the description below, and partly understood by those skilled in the art through study and practice of this application. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0023] Figure 1 This is a flowchart illustrating the stability control method for high-level unmanned forklift operations provided in this application embodiment; Figure 2 This is a schematic diagram of a sub-step of step S105 provided in an embodiment of this application; Figure 3This is a schematic diagram of the structure of the unmanned forklift high-position operation stability control device provided in the embodiments of this application; Figure 4 This is a schematic diagram of the overall structure of the side support mechanism 301 provided in the embodiments of this application; Figure 5 This is provided by the embodiments of this application. Figure 4 Enlarged view of point A in the middle; Figure 6 This is a schematic diagram of the rotational centripetal line of the hydraulic cylinder centerline and the side support leg provided in the embodiments of this application; Figure 7 This is a schematic diagram of the hydraulic control system 302 provided in an embodiment of this application; Figure 8 This is a schematic diagram of the controller 303 provided in the embodiments of this application; Figure 9 This is a schematic diagram of the overall structure of the side support structure 301 in the folded state provided in the embodiment of this application.

[0024] The following are the labels in the attached diagram: 1-Forklift body; 2-Fixed support A; 3-Hydraulic cylinder; 4-Fixed support B; 5-Side support leg; 6-Support wheel; 7-Pin A; 8-Copper sleeve; 9-Snap ring; 10-Pin B; 11-Pin C; 12-Pin D; 13-Cylinder centerline; 14-Side support leg rotation centerline. Detailed Implementation

[0025] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0026] The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. In this application, "at least one" means one or more, and "more than one" means two or more. The terms "first," "second," and other ordinal terms used in this application may be used to describe various constituent elements, but these constituent elements are not limited by these terms. The purpose of using these terms is solely to distinguish one constituent element from others and should not be construed as indicating or implying relative importance. For example, without departing from the scope of this application, a first constituent element may be named a second constituent element, and similarly, a second constituent element may be named a first constituent element.

[0027] refer to Figure 1 , Figure 1This is a flowchart illustrating the stability control method for high-level operation of an unmanned forklift provided in an embodiment of this application. Figure 1 As shown, the method for controlling the stability of unmanned forklifts in high-position operations includes at least the following steps: S101, Obtain the operating parameters of the unmanned forklift, and determine whether the unmanned forklift has entered the high-level operation mode based on the operating parameters; S103, when it is determined that the unmanned forklift has entered the high-level operation mode, the side support mechanisms installed on the left and right sides of the unmanned forklift body are controlled to extend outward synchronously until the support wheels at the end of each side support mechanism are in contact with the ground, so that the unmanned forklift changes from the original three-point support state to a five-point support state including the two side support wheels. S105, the extension length of the left and right side support mechanisms can be adjusted independently so that the left and right support wheels are in contact with the ground with a preset grounding pressure; S107, with the left and right side support mechanisms in the extended state, control the forks of the unmanned forklift to perform lifting and / or lateral movement operations. S109: When the high-level operation is detected to be completed, the left and right side support mechanisms are controlled to retract inward simultaneously, so that the unmanned forklift returns to normal driving status.

[0028] Specifically, when the method begins execution, it first enters the state recognition phase. The controller of the unmanned forklift acquires the forklift's operating parameters in real time, including but not limited to fork lifting height, current operation instructions, and navigation positioning information. The controller determines whether the unmanned forklift has entered the high-level operation mode based on the acquired operating parameters (step S101). The determination criteria include at least one of the following: the fork lifting height reaches or exceeds a preset height threshold (e.g., 4 meters), a high-level operation instruction is received from an external control system (such as a warehouse management system), or the unmanned forklift is determined to have entered a preset high-level operation area (such as a high-bay racking area) based on navigation positioning information. When any of these conditions are met, the controller determines that the unmanned forklift has entered the high-level operation mode.

[0029] Once the controller determines that the unmanned forklift has entered the high-position operation mode, the method enters the support deployment stage. The controller sends an extension command to the hydraulic control system, which then controls the side support mechanisms installed on the left and right sides of the forklift body to deploy outwards synchronously. Driven by the hydraulic cylinders, the side support mechanisms swing outwards around the hinge points until the support wheels at the ends of the side support mechanisms contact the ground. At this point, the unmanned forklift changes from its original three-point support structure (one drive wheel and two load wheels) to a five-point support structure, that is, two additional support points are added to the left and right sides of the vehicle body on the basis of the original three-point support (step S103). During the outward deployment of the side support mechanisms, the forward and reverse drive functions of the unmanned forklift are maintained, and the rolling axis direction of the support wheels is perpendicular to the forward and reverse direction of the unmanned forklift, so that the support wheels can roll along the forward and reverse direction of the unmanned forklift, facilitating fine-tuning of the position during subsequent operations.

[0030] After the aforementioned side support mechanism is deployed, the method enters the adaptive grounding phase. In some embodiments, refer to Figure 2 , Figure 2 This is a schematic diagram of a sub-step of step S105 provided in an embodiment of this application. For example... Figure 2 As shown, the process of independently adjusting the extension length of the left and right side support mechanisms to ensure that both left and right support wheels are in contact with the ground with a preset grounding pressure includes at least the following steps: S201, the oil inlet and return flow of the oil cylinders in the left and right side support mechanisms are controlled by electromagnetic multi-way valves respectively. S203, real-time detection of the hydraulic cylinder pressure on both the left and right sides; S205, adjust the extension length of the left and right cylinders respectively until the cylinder pressure of both the left and right cylinders reaches the preset ground pressure threshold.

[0031] Specifically, firstly, the oil inlet and outlet flow rates of the hydraulic cylinders in the left and right side support mechanisms are controlled independently by electromagnetic multi-way valves, achieving independent control of the two hydraulic cylinders. Then, the hydraulic cylinder pressures on both sides are monitored in real time, and the pressure signals are fed back to the controller. Finally, the controller adjusts the extension lengths of the left and right hydraulic cylinders according to the real-time monitored cylinder pressures. When the ground is flat, the extension lengths of the two hydraulic cylinders are basically the same; when the ground is uneven, the controller adjusts the extension lengths of the two hydraulic cylinders separately to ensure that both support wheels are reliably grounded. The adjustment process continues until the hydraulic cylinder pressures on both sides reach the preset grounding pressure threshold. At this point, both support wheels are in contact with the ground with the preset grounding pressure, ensuring the reliability of the support (step S105).

[0032] After the adaptive grounding phase is completed, the method enters the high-position operation phase. With the side support mechanism extended and the support wheels reliably grounded, the controller controls the forks of the unmanned forklift to perform lifting and / or lateral movement operations (step S107). During this process, to ensure operational flexibility and safety, the unmanned forklift is allowed to move forward and backward at a speed limit lower than the normal travel speed. The speed limit can be a preset fixed value (e.g., 0.5 m / s), or it can be determined in real time based on the fork lifting height—the higher the lifting height, the lower the speed limit, providing greater safety assurance. This speed-limited movement control satisfies the need for fine-tuning the position during high-position operations while avoiding the safety risks associated with high-speed movement.

[0033] After the high-level operation phase is completed, the method enters the support retraction phase. The controller detects the completion of the high-level operation under the following conditions: the forks have descended to a safe height (e.g., 3 meters), a completion command has been received, or the operation has been completed based on the workflow. When the high-level operation is detected as complete, the controller sends a retraction command to the hydraulic control system, controlling the left and right side support mechanisms to retract inwards synchronously. Driven by the hydraulic cylinders, the side support mechanisms swing inwards around the hinge point, retracting to both sides of the forklift body, allowing the unmanned forklift to return to normal driving status and move freely to the next operating position (step S109).

[0034] Through the coordinated operation of the above five stages, the unmanned forklift high-level operation stability control method provided in this application embodiment achieves automatic control of the stability of the unmanned forklift during high-level operation. This method accurately determines operational needs through the state recognition stage, quickly establishes a five-support-point structure through the support deployment stage, overcomes the influence of uneven ground through the adaptive grounding stage, balances operational flexibility and safety during the high-level operation stage, and restores driving capability through the support retraction stage. The entire control process is logically clear and responsive, fully adapting to the automated operation requirements of unmanned forklifts. The longitudinal anti-tipping capability of the unmanned forklift during high-level operation is significantly improved, the body sway amplitude is greatly reduced, and the rated load capacity is significantly increased. Simultaneously, since the side support mechanism is fully retracted in the non-operational state, it does not affect the unmanned forklift's ability to pass through narrow passages, achieving a practical unity of passability and stability.

[0035] Based on the same technical concept, this application also provides a stability control device for high-level operation of unmanned forklifts. (Reference) Figure 3 , Figure 3 This is a schematic diagram of the structure of the unmanned forklift high-position operation stability control device provided in the embodiments of this application. Figure 3 As shown, the device includes a side support mechanism 301, a hydraulic control system 302, and a controller 303, wherein: Two sets of side support mechanisms 301 are provided, symmetrically installed on the left and right sides of the unmanned forklift body. The two sets of side support mechanisms 301 are structurally identical and arranged symmetrically to ensure the force balance of the unmanned forklift in the supported state; The hydraulic control system 302 is connected to the oil cylinders in the side support mechanism 301 respectively, and is used to independently control the extension and retraction of each oil cylinder; The controller 303 is electrically connected to the hydraulic control system 302 and is used to control the side support mechanism 301 to switch between the retracted state and the supported state according to the working state of the unmanned forklift.

[0036] In some embodiments, reference Figure 4 and Figure 5 , Figure 4 This is a schematic diagram of the overall structure of the side support mechanism 301 provided in the embodiments of this application. Figure 5 This is provided by the embodiments of this application. Figure 4 Enlarged diagram of point A in the middle. (See diagram below.) Figure 4 and Figure 5 As shown, each side support mechanism 301 includes a fixed support A2, a hydraulic cylinder 3, a fixed support B4, a side support leg 5, and a support wheel 6, wherein: The aforementioned fixed supports A2 and B4 are respectively fixedly connected to preset positions on the side of the unmanned forklift body 1. Specifically, the fixed supports A2 and B4 can be fixed to the unmanned forklift body 1 by bolts or welding to ensure the reliability of the connection. The installation positions of the fixed supports A2 and B4 can be adjusted according to the size of the unmanned forklift model to ensure that the hydraulic cylinder 3 has a suitable stroke range; The cylinder body end of the aforementioned hydraulic cylinder 3 is hinged to the fixed support A2, and the piston rod end of the hydraulic cylinder 3 is hinged to the side support leg 5. Specifically, the cylinder body end of the hydraulic cylinder 3 is hinged to the fixed support A2 via pin A7, and the piston rod end of the hydraulic cylinder 3 is hinged to the side support leg 5 via pin C11. As a power actuator, the hydraulic cylinder 3 extends or retracts under the control of the hydraulic control system 302, driving the side support leg 5 to swing. The aforementioned side support leg 5 is hinged to the fixed support B4, allowing the side support leg 5 to swing horizontally around the hinge axis. Specifically, the side support leg 5 is hinged to the fixed support B4 via pin D12. The side support leg 5 is a key component for transmitting force and torque, connecting the vehicle body to the support wheel 6. The aforementioned support wheel 6 is rotatably connected to the end of the side support leg 5, and the axis of rotation of the support wheel 6 is perpendicular to the forward and backward direction of the unmanned forklift. Specifically, the support wheel 6 is rotatably connected to the end of the side support leg 5 via pin B10. When extended, the support wheel 6 contacts the ground, providing a stable fulcrum, and can roll as the unmanned forklift moves forward or backward, with both directions of movement aligned, reducing sliding friction with the ground.

[0037] It should be noted that the connection relationship of each component in the side support mechanism 301 is as follows: The cylinder body end of the hydraulic cylinder 3 is hinged to the fixed support A2 via pin A7; The piston rod end of the hydraulic cylinder 3 is hinged to the side support leg 5 via pin C11; The side support leg 5 is hinged to the fixed support B4 via pin D12; The support wheel 6 is rotatably connected to the end of the side support leg 5 via pin B10.

[0038] Specifically, wear-resistant copper sleeves 8 and axial limiting springs 9 are respectively provided between pins A7, B10, C11, and D12 and their corresponding connecting holes. The wear-resistant copper sleeves 8 are used to reduce wear between the pins and the connecting holes and extend their service life; the axial limiting springs 9 are used to prevent axial movement of the pins and ensure connection reliability.

[0039] In some embodiments, reference Figure 6 , Figure 6 This is a schematic diagram of the rotational centripetal line of the hydraulic cylinder's central axis and the side support leg, provided in an embodiment of this application. (See diagram below.) Figure 6 As shown, in each side support mechanism 301, the central axis 13 of the hydraulic cylinder 3 and the rotational centripetal line 14 of the side support leg 5 remain non-collinear during the swinging process of the side support leg 5. This structural design effectively avoids "dead points" during the mechanism's movement, ensuring smooth and reliable operation of the side support mechanism without any jamming.

[0040] In some embodiments, reference Figure 7 , Figure 7 This is a schematic diagram of the hydraulic control system 302 provided in an embodiment of this application. Figure 7 As shown, the hydraulic control system 302 includes a hydraulic pump station 701 and an electromagnetic multi-way valve group 703, wherein: The hydraulic pump station 701 is connected to the power system of the unmanned forklift and is used to provide hydraulic power. The hydraulic pump station 701 can be powered by the unmanned forklift's battery to drive the hydraulic pump and provide pressure and flow to the entire hydraulic system; The inlet of the electromagnetic multi-way valve assembly 703 is connected to the outlet of the hydraulic pump station 701, and the return port of the electromagnetic multi-way valve assembly 703 is connected to the return port of the hydraulic pump station 701. The electromagnetic multi-way valve assembly 703 has multiple working ports, which are respectively connected to the cylinders 3 in the left and right side support mechanisms 301, and are used to control the extension and retraction of each cylinder 3. The electromagnetic multi-way valve assembly 703 receives control signals from the controller 303 and controls the flow direction and flow rate of hydraulic oil by energizing and de-energizing the electromagnet, thereby precisely controlling the extension and retraction speed of the hydraulic cylinder 3. Because of independent control, the two hydraulic cylinders 3 can be adjusted separately, achieving an adaptive grounding function.

[0041] In some embodiments, reference Figure 8 , Figure 8 This is a schematic diagram of the controller 303 provided in an embodiment of this application. Figure 8 As shown, the controller 303 includes a status detection module 801, an extension control module 803, a grounding adjustment module 805, and a retraction control module 807, wherein: The aforementioned status detection module 801 is connected to the onboard sensor signals of the unmanned forklift and is used to acquire the operating parameters of the unmanned forklift and determine whether it has entered the high-level operation mode. Specifically, the status detection module 801 can acquire signals from the forklift lifting height sensor, navigation and positioning system, communication interface, etc., and comprehensively determine whether the unmanned forklift has entered the high-level operation mode. The determination criteria include at least one of the following: the forklift lifting height reaches or exceeds a preset height threshold, a high-level operation command is received from an external control system, or the unmanned forklift is determined to have entered a preset high-level operation area based on navigation and positioning information; The aforementioned extension control module 803 is signal-connected to the hydraulic control system 302 and is used to control the side support mechanisms 301 to extend outward synchronously when the system determines that it has entered the high-position operation mode. Specifically, the extension control module 803 sends a control signal to the solenoid multi-way valve group 703, causing the cylinder 3 to extend and driving the side support legs 5 to swing outward. The extension control module 803 controls the synchronous movement of the two side support mechanisms 301 to ensure the force balance of the unmanned forklift in the supported state; The aforementioned grounding adjustment module 805 is signal-connected to the hydraulic control system 302 and is used to adjust the extension length of the left and right cylinders 3 respectively, so that the left and right support wheels 6 are both in contact with the ground with a preset grounding pressure. Specifically, the grounding adjustment module 805 receives feedback signals from the cylinder pressure sensors and adjusts the extension amount of the two cylinders 3 respectively through the electromagnetic multi-way valve group 703 until the pressure of both cylinders reaches the preset grounding pressure threshold. The grounding adjustment module 805 achieves self-adaptation to the flatness of the ground, ensuring that the two support wheels 6 can be reliably grounded. The aforementioned retraction control module 807 is signal-connected to the hydraulic control system 302 and is used to control the side support mechanisms 301 to retract inward synchronously after the completion of high-level operation. Specifically, the retraction control module 807 sends a control signal to the electromagnetic multi-way valve group 703, causing the cylinder 3 to retract and drive the side support legs 5 to swing inward, retracting to both sides of the vehicle body.

[0042] It should be noted that the controller 303 can be implemented using a programmable logic controller (PLC), a microcontroller (MCU), or an embedded industrial control computer. The specific selection can be determined according to the control architecture of the unmanned forklift.

[0043] In some embodiments, the side support mechanism 301 has a retracted state and a supported state, wherein: refer to Figure 9 , Figure 9 This is a schematic diagram of the overall structure of the side support structure 301 in the folded state provided in an embodiment of this application. Figure 9 As shown, in the retracted state, the side support legs 5 and support wheels 6 are retracted to both sides of the unmanned forklift body 1. The horizontal projection of the side support mechanism 301 does not exceed the width of the unmanned forklift body 1, ensuring that the unmanned forklift is not affected by the side support mechanism during normal operation and can pass through narrow passages. At this time, the unmanned forklift maintains its original three-point support structure, providing good passability and flexibility. In the supported state, the support wheels 6 on both sides simultaneously contact the ground, forming additional support points on both sides of the unmanned forklift body 1. This transforms the unmanned forklift from a three-point support structure to a five-point support structure, greatly improving longitudinal stability. At this time, the unmanned forklift has better anti-tipping capability when performing high-level lifting and lateral movement operations.

[0044] Based on the same technical concept, this application also provides an unmanned forklift, including a forklift body and the aforementioned unmanned forklift high-position operation stability control device. The controller 303 of the unmanned forklift high-position operation stability control device is communicatively connected to the vehicle controller of the forklift body. Exemplarily, when the unmanned forklift receives a high-position operation task, the vehicle controller sends the task information to the controller 303 of the stability control device, and the controller 303 automatically executes the aforementioned control method. After the unmanned forklift completes the high-position operation, the controller 303 automatically controls the side support mechanism 301 to retract, restoring the driving state. The entire process requires no manual intervention and fully adapts to the automated operation requirements of unmanned forklifts. This unmanned forklift can be a laser-navigated, magnetic-navigated, visual-navigated, or SLAM-navigated unmanned forklift; its specific navigation method does not affect the implementation of the technical solution of this application.

[0045] It should be noted that the order of description of the embodiments in this application is not intended to limit the priority of the embodiments.

[0046] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application and in its specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0047] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many forms under the guidance of this application without departing from the spirit and scope of protection of the claims. All equivalent transformations made under the inventive concept of this application using the content of this application's specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A method for controlling the stability of unmanned forklifts operating at high positions, characterized in that, include: Obtain the operating parameters of the unmanned forklift, and determine whether the unmanned forklift has entered the high-position operation mode based on the operating parameters; When it is determined that the unmanned forklift has entered the high-level operation mode, the side support mechanisms installed on the left and right sides of the unmanned forklift body are controlled to extend outward synchronously until the support wheels at the end of each side support mechanism are in contact with the ground, so that the unmanned forklift changes from the original three-point support state to a five-point support state including the two side support wheels. The extension length of the left and right side support mechanisms can be adjusted independently to ensure that the left and right support wheels are in contact with the ground with a preset grounding pressure. With the left and right side support mechanisms extended, control the forks of the unmanned forklift to perform lifting and / or lateral movement operations; Once the high-level operation is completed, the left and right side support mechanisms are controlled to retract inward simultaneously, allowing the unmanned forklift to return to normal driving status.

2. The method for controlling the stability of unmanned forklifts operating at high positions according to claim 1, characterized in that, The criteria for determining whether an unmanned forklift has entered the high-level operation mode include at least one of the following: the fork lifting height reaches or exceeds a preset height threshold, a high-level operation command is received from an external control system, or the unmanned forklift is determined to have entered a preset high-level operation area based on navigation and positioning information.

3. The method for controlling the stability of unmanned forklifts operating at high positions according to claim 1, characterized in that, As the side support mechanisms on the left and right sides of the unmanned forklift body unfold outward, the unmanned forklift maintains its forward and backward driving functions, and the rolling axis of the support wheel is perpendicular to the forward and backward direction of the unmanned forklift, so that the support wheel rolls along the forward and backward direction of the unmanned forklift.

4. The method for controlling the stability of unmanned forklifts operating at high positions according to claim 1, characterized in that, The method of independently adjusting the extension length of the left and right side support mechanisms so that both left and right support wheels are in contact with the ground with a preset grounding pressure includes: The oil inlet and return volumes of the hydraulic cylinders in the left and right side support mechanisms are controlled by electromagnetic multi-way valves respectively. Real-time monitoring of the hydraulic cylinder pressure on both the left and right sides; Adjust the extension length of the left and right cylinders respectively until the cylinder pressure of both cylinders reaches the preset ground pressure threshold.

5. The method for controlling the stability of unmanned forklifts operating at high positions according to claim 1, characterized in that, With the left and right side support mechanisms extended, the unmanned forklift is allowed to move forward and backward at a speed limit lower than the normal driving speed. The speed limit is a preset value or is determined in real time based on the lifting height of the forks.

6. A stability control device for high-position operation of an unmanned forklift, characterized in that, include: The side support mechanism is provided in two sets, which are symmetrically installed on the left and right sides of the unmanned forklift body (1). Each side support mechanism includes a fixed support A (2), a fixed support B (4), a hydraulic cylinder (3), a side support leg (5), and a support wheel (6). Among them, the fixed support A (2) and the fixed support B (4) are respectively fixedly connected to the preset positions on the side of the unmanned forklift vehicle body (1); The cylinder body end of the oil cylinder (3) is hinged to the fixed support A (2), and the piston rod end of the oil cylinder (3) is hinged to the side support leg (5). The side support leg (5) is hinged to the fixed support B (4), so that the side support leg (5) can swing around the hinge axis in the horizontal plane. The support wheel (6) is rotatably connected to the end of the side support leg (5), and the rotation axis of the support wheel (6) is perpendicular to the forward and backward direction of the unmanned forklift. The hydraulic control system is connected to the cylinders (3) in each of the side support mechanisms and is used to independently control the extension and retraction of each cylinder (3); The controller, electrically connected to the hydraulic control system, is used to control the side support mechanism to switch between a retracted state and a supported state according to the working state of the unmanned forklift.

7. The unmanned forklift high-position operation stability control device according to claim 6, characterized in that, In each of the side support mechanisms, the central axis (13) of the oil cylinder (3) and the rotation centripetal line (14) of the side support leg (5) always remain non-collinear during the swinging process of the side support leg (5).

8. The unmanned forklift high-position operation stability control device according to claim 6, characterized in that, The rolling direction of the support wheel (6) is consistent with the forward and backward direction of the unmanned forklift, so that the support wheel (6) can roll with the forward or backward movement of the unmanned forklift when it contacts the ground.

9. The unmanned forklift high-position operation stability control device according to claim 6, characterized in that, The hydraulic control system includes: The hydraulic pump station is connected to the power system of the unmanned forklift and is used to provide hydraulic power. The electromagnetic multi-way valve assembly has an oil inlet connected to the oil outlet of the hydraulic pump station and an oil return port connected to the oil return port of the hydraulic pump station. The electromagnetic multi-way valve assembly has multiple working oil ports, which are respectively connected to the oil cylinders (3) in the left and right side support mechanisms, and are used to control the extension and retraction of each oil cylinder (3).

10. The unmanned forklift high-position operation stability control device according to claim 6, characterized in that, The controller includes: The status detection module is connected to the on-board sensor signals of the unmanned forklift to obtain the operating parameters of the unmanned forklift and determine whether it has entered the high-position operation mode. An extension control module is connected to the hydraulic control system signal and is used to control the support mechanisms on each side to extend outward synchronously when the high-level operation mode is determined to be entered. The grounding adjustment module is connected to the hydraulic control system signal and is used to adjust the extension length of the left and right cylinders (3) respectively, so that the left and right support wheels (6) are in contact with the ground with a preset grounding pressure. The retraction control module is connected to the hydraulic control system and is used to control the support mechanisms on each side to retract inward synchronously after the completion of the high-level operation.

11. The unmanned forklift high-position operation stability control device according to claim 6, characterized in that, The fixed support A (2) and the fixed support B (4) are fixedly connected to the unmanned forklift body (1) by bolts or welding.

12. The unmanned forklift high-position operation stability control device according to claim 6, characterized in that, In each of the aforementioned side support mechanisms: The cylinder body end of the oil cylinder (3) is hinged to the fixed support A (2) via a pin A (7); The piston rod end of the oil cylinder (3) is hinged to the side support leg (5) via a pin C (11); The side support leg (5) is hinged to the fixed support B (4) via pin D (12); The support wheel (6) is rotatably connected to the end of the side support leg (5) via pin B (10).

13. The unmanned forklift high-position operation stability control device according to claim 12, characterized in that, Wear-resistant copper sleeves (8) and axial limiting snap rings (9) are respectively provided between the pin A (7), the pin B (10), the pin C (11) and the pin D (12) and the corresponding connecting holes.

14. The unmanned forklift high-position operation stability control device according to claim 6, characterized in that, The side support mechanism has a retracted state and a supported state: In the retracted state, the side support legs (5) and the support wheels (6) are retracted to both sides of the unmanned forklift body (1), and the projection of the side support mechanism in the horizontal direction does not exceed the width range of the unmanned forklift body (1). In the supported state, the support wheels (6) on the left and right sides simultaneously contact the ground, forming additional support points on the left and right sides of the unmanned forklift body (1), so that the unmanned forklift forms a five-support-point support structure.

15. An unmanned forklift, characterized in that, include: Forklift body; And the unmanned forklift high-position operation stability control device as described in any one of claims 6 to 14, wherein the controller of the unmanned forklift high-position operation stability control device is communicatively connected to the vehicle controller of the forklift body.

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