Intelligent AGV forklift for narrow space

Abstract

The invention provides an intelligent AGV forklift for a narrow space, and relates to the technical field of intelligent logistics equipment. Comprising a body part, a portal part and a sensor system. The portal frame part comprises a portal frame main body, a fork arm carrier and a built-in lateral moving frame; a goods blocking frame and two independent pallet fork assemblies are arranged on the built-in lateral moving frame. The pallet fork assembly comprises a base, a pallet fork arm, a hydraulic driving unit and a position detecting unit and is used for driving the pallet fork arm to be folded and unfolded and detecting the position. The sensor system comprises a top sensing radar, a rear obstacle avoidance radar and two side obstacle avoidance radars which are installed on the top of the door frame, the rear lower portion of the vehicle body and the lower portions of the left side and the right side of the vehicle body respectively. The scheme is compact in structure, accurate in sensing and suitable for operation in a narrow space.

Description

Technical Field

[0001] This invention relates to the field of intelligent logistics equipment technology, and in particular to an intelligent AGV forklift for use in confined spaces. Background Technology

[0002] Automated Guided Vehicles (AGVs) forklifts, as core equipment in modern intelligent logistics and manufacturing, play an increasingly important role in warehousing, workshop material handling, and other fields. With the continuous deepening of application scenarios, especially the increasingly urgent need for operations in extremely confined spaces such as railway freight cars, inside containers, and narrow warehouse aisles, unprecedented challenges are posed to the structural compactness, movement flexibility, and environmental perception intelligence of AGV forklifts.

[0003] Existing AGV forklifts typically face several technical bottlenecks when operating in confined spaces: In terms of overall structure and layout, traditional AGV forklift frames are mostly constructed from welded steel frames, requiring additional independent counterweights to maintain balance. This modular structure not only results in a bulky and heavy vehicle, making it difficult to navigate narrow spaces, but also makes the welded joints prone to fatigue cracks under long-term loads, posing safety hazards. Furthermore, the dispersed layout of key components such as batteries, controllers, and hydraulic pumps leads to complex wiring and piping arrangements, consuming valuable internal space and hindering miniaturization and integrated design.

[0004] Regarding the operational flexibility of the fork mechanism, traditional forks are mostly of fixed width or can only be manually adjusted. When entering environments with strictly limited width, such as train carriages, fixed forks result in an excessively large overall turning radius for the AGV, making it impossible to turn flexibly and operate close to the side walls. Although some foldable fork designs exist, they mostly rely on manual operation or simple mechanical linkages, lacking automatic drive and precise position feedback, and thus cannot meet the requirements of real-time and precise control of the fork status in fully automated AGV operations.

[0005] Regarding the configuration of environmental perception systems, the sensor layout of common AGVs often focuses on achieving a single function (such as navigation or obstacle avoidance), and the installation positions lack systematic optimization. Sensors with different functions (such as LiDAR, millimeter-wave radar, and cameras) may interfere with each other or have blind spots, especially insufficient detection of low obstacles near the ground, sides, and rear of the vehicle. In complex environments such as truck bodies and containers, blind spots can easily lead to collisions. In addition, sensor brackets are often simple in structure, easily damaged, or obstructed by dirt, affecting the reliability of perception and making it difficult to ensure stable operation under harsh conditions. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide an intelligent AGV forklift for use in confined spaces, which has the advantages of compact structure, accurate perception, and adaptability to the needs of confined space operations.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This application provides an intelligent AGV forklift for use in confined spaces, the technical solution of which is as follows: It includes a body section and a mast section, and a sensor system mounted on the body section and the mast section; its characteristic is:

[0009] The mast section includes the mast body, the fork carriage which is lifted and mounted on the mast body, and the built-in side shifter mounted on the fork carriage; the built-in side shifter is fixedly mounted with a backrest and two independent fork assemblies;

[0010] The fork assembly includes a base, fork arms, a hydraulic drive unit, and a position detection unit. The base is fixed to the built-in side shift frame, the fork arms are hinged to the base, and the hydraulic drive unit connects the base and the fork arms to drive the fork arms to fold and unfold relative to the base. The position detection unit is used to detect the folded and unfolded positions of the fork arms.

[0011] The sensor system includes:

[0012] o A top sensing radar, mounted on top of the gantry section via a bracket;

[0013] o A rear obstacle avoidance radar is installed on the lower rear side of the vehicle body;

[0014] Two side obstacle avoidance radars are symmetrically installed on the lower left and right sides of the vehicle body.

[0015] This technical solution constructs an overall AGV forklift architecture adapted to operation in confined spaces through integrated structural design and synergistic optimization of the intelligent sensing system. The mast adopts a combination design of built-in side-shifting frames and independent fork assemblies, allowing two sets of forks to be independently folded and adjusted in width. Combined with a hydraulic drive unit, this enables automated unfolding, solving the problem of excessive turning radius in traditional fixed forks. The hinged structure between the base and fork arms in the fork assembly, combined with hydraulic drive, provides real-time status feedback through a position detection unit, ensuring precise control of the fork's folding angle in confined spaces. The sensor system forms a three-dimensional sensing network through a top radar covering the high space, and layered rear and side radars. The combination of a lower-mounted rear radar and symmetrically installed side radars effectively eliminates blind spots near the ground. This multi-level sensor layout in the vehicle body and mast ensures omnidirectional obstacle detection capability while maintaining structural compactness, overcoming the shortcomings of traditional AGVs in sensing insufficiently in complex and confined environments.

[0016] Furthermore, this application also proposes that the hydraulic drive unit includes at least one drive cylinder and a control valve assembly, wherein the cylinder body end of the drive cylinder is hinged to the base, the piston rod end of the drive cylinder is hinged to the fork arm, and the control valve assembly is connected to the drive cylinder through an oil circuit.

[0017] Furthermore, this application also proposes that the position detection unit includes a first sensor disposed on the rotation path of the fork arm for detecting the folded position and unfolded position of the fork arm; the first sensor is a limit switch, proximity switch or angle sensor, which is fixedly installed on the base; and a trigger element that cooperates with the first sensor is disposed on the fork arm.

[0018] This technical solution achieves precise control and real-time feedback of the fork arm's movement state through a coordinated design of hydraulic drive and position detection. The drive cylinder uses a double-hinged connection to link the base and the fork arm, forming a stable force transmission path. The control valve group can precisely adjust the oil pressure and flow rate, ensuring smooth and controllable folding and unfolding of the fork arm. The position detection unit sets detection points at key locations along the fork arm's rotation path by fixing a first sensor to the base and cooperating with a trigger on the fork arm. Limit switches or proximity switches can accurately capture mechanical displacement, while angle sensors can continuously monitor the rotation angle. The selection of multiple sensor types adapts to different detection accuracy requirements. The spatial design of the trigger and sensor avoids the shortcomings of traditional detection devices that are susceptible to vibration interference, ensuring reliable detection of the fork arm's extreme positions.

[0019] Furthermore, this application also proposes that the inner end of the fork arm is hinged to the base via an L-shaped rocker arm; one end of the L-shaped rocker arm is fixedly connected to the inner end of the fork arm, and the other end is hinged to the base; the piston rod end of the drive cylinder of the hydraulic drive unit is hinged to the rod body of the L-shaped rocker arm.

[0020] This technical solution reconstructs the folding kinematics model of the fork arm by introducing an L-shaped rocker arm as a transmission intermediary. The double-hinged structure of the L-shaped rocker arm between the fork arm and the base creates a spatially offset arrangement between the fork arm's rotation axis and the base. This design overcomes the planar motion limitations of traditional fork arm direct hinges, enabling the fork arm to generate a complex motion trajectory during folding. The arrangement of the piston rod end of the hydraulic drive unit hinged to the body of the L-shaped rocker arm converts the linear driving force into a lever torque of the L-shaped rocker arm. Through the optimized design of the length ratio of the two arms of the rocker arm, the driving torque is amplified. This structure not only reduces the output force requirements of the hydraulic drive unit but also enhances system rigidity by changing the fulcrum position, preventing unexpected deformation of the fork arm under load. The special geometry of the L-shaped rocker arm guides the fork arm to contract towards the vehicle's centerline during folding, significantly reducing the lateral space occupied by the fork arm in its extended state. This spatial compression characteristic is specifically matched to the stringent limitations on vehicle width during operation in narrow spaces.

[0021] Furthermore, this application also proposes to include a second sensor for detecting whether the goods have reached the correct fork position, and a third sensor for detecting whether the fork tip has touched an obstacle;

[0022] • The second sensor is mounted on an L-shaped rocker arm or fork arm on one side and is connected to a baffle mechanism that can be touched by the goods;

[0023] The third sensor is a contact or photoelectric sensor with a buffer rebound structure, located at the front end of the fork arm.

[0024] This technical solution addresses the issues of cargo positioning and obstacle avoidance during forklift operations by employing two types of sensors. The second sensor, with detection points positioned on an L-shaped lever or fork arm and integrated with a movable baffle mechanism, triggers a signal when cargo contacts the baffle, accurately determining whether the cargo has fully entered the designated forklift area and preventing forklift failure or tipping due to cargo misalignment. The third sensor, a contact or photoelectric sensor with a buffer and rebound structure at the fork's front end, can detect obstacles through physical contact or provide early warnings through non-contact detection. The buffer structure effectively absorbs impacts, preventing sensor damage, and ensures timely cessation of movement upon encountering an obstacle, guaranteeing operational safety. The placement and structural design of the two sensor types complement each other: the second sensor focuses on verifying cargo positioning during the forklift operation, while the third sensor concentrates on detecting obstacles along the path, jointly improving the accuracy and safety of forklift operations in confined spaces.

[0025] Furthermore, this application also proposes to include a fourth sensor for detecting the lateral displacement position of the built-in side shifter, a height sensor for detecting the lifting height of the fork carriage, and a tilt sensor for detecting the tilt angle of the fork carriage.

[0026] • The pull wire end of the fourth sensor is fixed to the moving part of the built-in side shift frame through sensor bracket II, and its main body is fixed to the fork carriage through sensor bracket I;

[0027] • The main body of the height sensor is fixed to the upper side of the mast body through sensor bracket I, and its pull wire end is fixed to the fork carriage through sensor bracket II;

[0028] • The tilt sensor is fixed to a component on the fork carriage that does not tilt, and its lever moves with the tilting part of the fork carriage.

[0029] This technical solution achieves precise detection of the fork mechanism's motion state through the coordinated configuration of a multi-dimensional sensing system. The fourth sensor adopts a wire-connected, separate mounting structure, connecting to the moving parts via sensor bracket II, enabling real-time capture of the displacement of the built-in side-shifting frame, ensuring the lateral positioning accuracy of the forks in confined spaces. The height sensor, through wire-connected measurement between the mast body and the fork carriage, converts the mechanical motion of the lifting mechanism into a linear displacement signal, solving the cumulative error problem inherent in traditional height detection. The tilt sensor, by fixing its body to a non-moving part of the fork carriage and utilizing the linkage structure between the lever and the tilting component, effectively isolates the interference of other directions of fork carriage movement on angle detection, improving the reliability of tilt angle measurement. The combined installation of these three sensors, optimized for the motion characteristics of side shifting, lifting, and tilting, forms a complementary detection mechanism, providing a multi-parameter feedback basis for the precise control of AGV forklifts in complex and confined environments.

[0030] Furthermore, this application also proposes that the sensor system further includes a top radar bracket for mounting the top sensing radar and a rear radar bracket for mounting the rear obstacle avoidance radar; the rear radar bracket has a Z-shaped structure, with one end set on the top surface of the vehicle body and the rear obstacle avoidance radar set on the other end surface of the rear radar bracket; the top surface of the vehicle body is a sloped surface so that the detection surface of the rear obstacle avoidance radar is tilted downwards and backwards.

[0031] Furthermore, this application also proposes that the sensor system further includes multiple cameras, including a front-view camera, a side-view camera, and a rear-view camera;

[0032] • The forward-facing camera is mounted at the end of the mast section, facing the front of the forks;

[0033] • Side-view cameras are installed on the left and right sides of the vehicle body, facing the forks and the side areas of the vehicle body;

[0034] • The rearview camera is mounted at the rear of the vehicle body, facing the rear of the vehicle.

[0035] Furthermore, this application also proposes that the body portion includes an integral cast frame, a front end connected to the frame, a drive wheel assembly mounted on the front end, a steering wheel assembly mounted on the frame, a battery assembly, and a hydraulic pump assembly.

[0036] • The frame is a single-piece cast structure with integrated counterweight function; the frame has battery mounting area, front mounting area, controller mounting area and steering axle mounting area;

[0037] • The battery mounting area is cast with a downwardly recessed battery placement groove, in which the battery assembly is installed. The front mounting area is located below the front side of the battery placement groove.

[0038] • The controller mounting area includes a controller mounting cavity formed by an inward recess at the rear of the chassis; the AGV control components and the vehicle control components are housed within the controller mounting cavity.

[0039] • The steering axle mounting area consists of a steering axle mounting cavity that opens downwards and backwards from the rear of the frame. This cavity extends through the bottom of the frame to mount the steering wheel assembly. The battery placement recess is connected to the controller mounting cavity and the steering axle mounting cavity via a cable pass-through hole.

[0040] This technical solution innovates the structure of the unibody cast frame, integrating the traditional separate welded frame and independent counterweights into a single casting. This eliminates the fatigue risk of welded structures and achieves internal counterweight functionality through material distribution, thereby significantly reducing the vehicle's size. The battery mounting area employs a downward-recessed battery placement groove design, embedding the battery components inside the frame rather than externally mounting them, lowering the center of gravity and saving space. The front mounting area is located below and in front of the battery groove, forming a vertically stacked spatial layout that optimizes the spatial relationship between the front of the vehicle and the battery. The controller mounting cavity forms a closed chamber through an inward recess at the rear of the frame, centrally protecting the AGV control components and the overall vehicle control components, avoiding wiring redundancy caused by dispersed layouts. The steering axle mounting cavity adopts a downward-opening, rearward-opening through-cavity structure, allowing the steering wheel assembly to be directly embedded in the bottom of the frame, reducing external protruding parts. Cable routing holes connect the battery, controller, and steering axle areas, enabling integrated wiring routing within the frame and solving the problem of easy damage from traditional exposed wiring. The integrated casting design of each functional area makes the frame itself a comprehensive carrier for load-bearing, counterweight, installation, and wiring, breaking through the technical limitations of the dispersed structure of traditional AGV forklifts.

[0041] Furthermore, this application also proposes that,

[0042] • The frame has air intake holes cast on both sides that are connected to the controller mounting cavity, and air intake plates are installed at the air intake holes;

[0043] • The side of the frame is cast with a charging component mounting cavity. The charging component mounting cavity is connected to the battery placement groove through a charging cable routing hole. An automatic charging plate assembly is installed inside the charging component mounting cavity.

[0044] • The frame portion above the battery mounting area is cast with an inwardly recessed front panel mounting cavity, which is connected to the controller mounting cavity;

[0045] • A mounting reference plate is cast inside the steering axle mounting cavity, which divides the steering axle mounting cavity into an upper steering motor mounting cavity and a lower steering wheel cavity; the rear axle adapter plate of the steering wheel assembly is fixed to the mounting reference plate.

[0046] This technical solution achieves optimized layout and improved structural stability of key functional modules through the integrated design of a multi-cavity cast frame. The combination of air intake holes and air intake plates on both sides of the frame forms a forced convection heat dissipation channel, effectively solving the problem of heat accumulation in electronic components such as controllers within the sealed cavity. The dedicated wiring hole design between the charging component mounting cavity and the battery recess ensures physical isolation of the charging lines while shortening wiring distance and avoiding the risk of wire tangling. The recessed structure of the front panel mounting cavity provides operators with a convenient maintenance interface while maintaining the flatness of the frame appearance. The spatial separation effect of the mounting base plate within the steering axle mounting cavity allows the steering motor and steering wheels to be placed in independent chambers, preventing mechanical interference and enhancing the overall torsional strength of the steering mechanism through the rigid fixation of the rear axle adapter plate. These features work together to achieve a comprehensive improvement in frame structure compactness, rational functional zoning, and operational reliability.

[0047] Furthermore, this application also proposes that a vehicle head is connected to the vehicle head mounting area, the vehicle head is located below the front side of the battery placement groove, and a hydraulic pump assembly is mounted on the vehicle head;

[0048] • The front mounting area and battery mounting area of ​​the chassis are covered by a front cover, which houses the battery pack and hydraulic pump assembly inside.

[0049] • The controller mounting area and steering axle mounting area of ​​the chassis are covered by a rear cover, which is used to house the steering motor cover of the AGV control components, the vehicle control components and the steering wheel device.

[0050] This technical solution systematically solves the problem of dispersed and exposed components in traditional AGV forklifts by optimizing the spatial layout of the front end and battery components and using a partitioned enclosure design. Specifically, the front end is positioned below and in front of the battery mounting recess, allowing the hydraulic pump assembly to be directly mounted on the front end. This fully utilizes the space under the front of the frame, avoids spatial interference between the hydraulic system and the battery components, and shortens the distance of the hydraulic pipeline layout. The integrated coverage of the front end mounting area and the battery mounting area by the front enclosure not only provides physical protection for the battery components and hydraulic pump assembly but also hides the connecting lines between them, reducing the risk of contamination and collisions to critical components from the external environment. The rear enclosure design, covering the controller mounting area and the steering axle mounting area, centrally encapsulates the AGV control components, vehicle control components, and steering motor, forming an independent protected area. This avoids interference from the steering motor's movement with the control components and allows for modular maintenance through the partitioned enclosure design—the front and rear enclosures can be disassembled separately for easy inspection of different functional modules. In addition, the staggered layout of the battery placement groove on the chassis and the mounting area at the front of the vehicle, combined with the streamlined coverage of the front and rear covers, effectively compresses the overall dimensions of the vehicle, reducing the risk of scraping of protruding parts of the AGV forklift when turning in narrow spaces.

[0051] As can be seen from the above, the intelligent AGV forklift and its sensor system and frame structure provided in this application solve the problems of large size and many blind spots of traditional AGV forklifts through integrated frame design, foldable fork assembly and multi-dimensional sensor layout. It has the advantages of compact structure, accurate perception and adaptability to the needs of narrow space operation. Attached Figure Description

[0052] Figure 1 This application provides a schematic diagram of the forks deployed in an intelligent AGV forklift for use in confined spaces.

[0053] Figure 2 This application provides a schematic diagram of fork storage for an intelligent AGV forklift used in confined spaces.

[0054] Figure 3 This application provides a schematic diagram showing the separation of the body and mast sections of an AGV forklift.

[0055] Figure 4 This is an exploded view of the gantry section.

[0056] Figure 5 This is a frontal perspective view of the fork assembly.

[0057] Figure 6 This is a three-dimensional view of the rear of the fork assembly.

[0058] Figure 7 This is a three-dimensional view of the bottom surface of the fork assembly.

[0059] Figure 8 Frontal three-dimensional view of the unibody cast chassis Figure 1 .

[0060] Figure 9 Frontal three-dimensional view of the unibody cast chassis Figure 2 .

[0061] Figure 10 This is a three-dimensional view of the rear of the unibody cast chassis.

[0062] Figure 11 This is a rear frontal projection view of the unibody cast frame.

[0063] Figure 12 This is an exploded view of the front structure of an AGV forklift.

[0064] Figure 13 The rear structure of the AGV forklift exploded. Figure 1 .

[0065] Figure 14 The rear structure of the AGV forklift exploded. Figure 2 .

[0066] Figure 15 A schematic diagram of the rear cover being installed at the rear end of the unibody cast frame. Detailed Implementation

[0067] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0068] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0069] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more, unless explicitly defined otherwise.

[0070] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0071] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0072] In existing technologies, automated guided vehicles (AGVs) and forklifts play an important role in warehousing and manufacturing. However, when facing narrow spaces such as railway freight cars and the interiors of containers, traditional forklifts suffer from problems such as bulky structures, insufficient fork adjustment, and blind spots in sensing. Split-type frames require additional counterweights, resulting in excessive size and weight; fixed forks are difficult to adapt to narrow turning requirements; and scattered sensor layouts can easily create detection blind spots, affecting operational safety.

[0073] To address these issues, the inventors discovered that traditional forklifts suffer from poor maneuverability in confined spaces, insufficient fork flexibility, and deficiencies in their sensing systems. By analyzing the synergistic relationship between the vehicle structure, fork drive mechanism, and sensor placement, they proposed an integrated frame design to reduce size, hydraulically driven forks for automatic folding, and optimized layered sensor layout to eliminate blind spots. This approach focuses on the synergistic optimization of structural compactness, automated operation, and comprehensive sensing capabilities.

[0074] like Figure 1-14 As shown, this application proposes an intelligent AGV forklift for use in confined spaces, including a body section 1, a mast section 2, and a sensor system. The mast section 2 includes a mast body 4, a fork carriage 5, and a built-in side-shift frame 6. The side-shift frame 6 is equipped with a stop rack 7 and two independent fork assemblies 8. The fork assembly 8 consists of a base 9, fork arms 10, a hydraulic drive unit, and a position detection unit. The hydraulic drive unit connects the base 9 and the fork arms 10 to achieve a folding action, and the position detection unit monitors the status of the fork arms 10.

[0075] The built-in side-shift frame 6 is a movable frame integrated into the fork carriage 5. Lateral displacement is achieved via linear guides or ball screw mechanisms to adjust the spacing between the two fork assemblies 8 to accommodate different cargo widths. The base 9 of the fork assembly 8 is made of high-strength cast aluminum alloy and is rigidly connected to the side-shift frame 6 via bolts to ensure the stability of the fork movements. The hydraulic drive unit includes a double-acting cylinder, with both ends hinged to the mounting lugs of the base 9 and the drive arm of the fork arm 10, respectively. The direction of the hydraulic circuit is controlled by an electromagnetic directional valve. The position detection unit uses a combination of Hall effect sensors and magnets. The magnets are fixed to the rotation axis of the fork arm 10, and the Hall effect sensors are installed at corresponding positions on the base 9 to detect the unfolding angle of the fork arm 10. Specifically, the mast section 2 achieves lateral position adjustment of the fork assembly 8 through the built-in side-shift frame 6. When the forklift enters a narrow passage, the hydraulic drive unit pushes the fork arm 10 to fold inward, reducing the overall lateral dimension of the vehicle. The position detection unit provides real-time feedback on the angle of the fork arm 10, and the control system adjusts the folding range according to a preset threshold.

[0076] Compared to existing technologies, traditional forklifts use a separate welded frame and fixed forks, resulting in an excessively large turning radius and the inability to automatically adjust fork width. This solution integrates a battery and controller into a single frame, reducing structural space requirements; independently hydraulically driven forks enable automatic width adjustment, coupled with position detection to ensure operational accuracy; through these technical solutions, this application achieves a compact vehicle structure, adapting to the need for passage through narrow spaces; the automatic fork width adjustment function reduces the turning radius and improves operational flexibility.

[0077] In a further embodiment, the fork assembly 8 includes a hydraulic drive unit and a position detection unit. The hydraulic drive unit comprises a drive cylinder 16 and a control valve assembly. The cylinder body of the drive cylinder 16 is hinged to the base 9, and the piston rod is hinged to the fork arm 10. The control valve assembly is connected to the drive cylinder 16 via an oil circuit. The position detection unit comprises a first sensor 18 and a trigger 19. The first sensor 18 is fixed to the base 9, and the trigger 19 is mounted on the fork arm 10 to detect the folding and unfolding positions of the fork arm 10. The drive cylinder 16 is an actuator that drives the fork arm 10 to move using hydraulic power. Specifically, it can be implemented using a double-acting cylinder. Its cylinder body is hinged to the base 9 to form a fixed fulcrum, and its piston rod is hinged to the fork arm 10 to form a power output point, thereby converting hydraulic energy into mechanical motion. The control valve assembly is a control device that regulates the flow direction and pressure of hydraulic oil. Specifically, it can be implemented using an electromagnetic proportional valve. By controlling the on / off state of the oil circuit and the flow rate, the extension / retraction speed and output force of the drive cylinder 16 are precisely adjusted. The first sensor 18 refers to the detection element that detects the rotational position of the fork arm 10. Specifically, it can be implemented using a limit switch, proximity switch, or angle sensor. For example, a limit switch triggers a signal through mechanical contact, a proximity switch triggers a signal through non-contact induction, and an angle sensor outputs a continuous position signal by measuring the rotation angle. The trigger element 19 refers to the physical structure that cooperates with the first sensor 18. Specifically, it can be implemented using a metal bump, magnet, or encoder disk. For example, a metal bump triggers the switch when it contacts the limit switch, and a magnet generates an electrical signal when it senses the proximity switch.

[0078] Specifically, the cylinder body of the drive cylinder 16 and the base 9 form a fixed rotation center through a hinge point. The hinge point between the piston rod and the fork arm 10 changes displacement with the extension and retraction of the cylinder, thereby driving the fork arm 10 to rotate around the base 9. The control valve group controls the extension and retraction speed of the piston rod by adjusting the flow rate of hydraulic oil entering the drive cylinder 16, ensuring smooth folding and unfolding of the fork arm 10. When the fork arm 10 rotates to the unfolded or folded position, the trigger 19 contacts or enters the sensing range of the first sensor 18, and the first sensor 18 outputs a position signal to the control system, confirming that the fork arm 10 has reached the predetermined position. When using an angle sensor, the sensor continuously monitors the rotation angle of the fork arm 10 and feeds the angle data back to the control system in real time, realizing dynamic position tracking during the movement. This solution combines hydraulic drive and electronic detection to achieve automated control and real-time position monitoring of the fork arm 10's movement. The combination of the drive cylinder 16 and the control valve group provides stable and controllable power output, offering higher load capacity and impact resistance compared to traditional motor drive solutions. The design of the first sensor 18 and the trigger 19 solves the problems of easy wear and low accuracy of mechanical limit devices, and adapts to different detection accuracy requirements through the optional configuration of multiple types of sensors.

[0079] like Figure 4-7 As shown, the inner end of the fork arm 10 is hinged to the base 9 via an L-shaped rocker arm 20; one end of the L-shaped rocker arm 20 is fixedly connected to the inner end of the fork arm 10, and the other end is hinged to the base 9; the piston rod end of the drive cylinder 16 of the hydraulic drive unit is hinged to the rod body of the L-shaped rocker arm 20. The L-shaped rocker arm 20 is a rigid connecting member with two mutually perpendicular arm segments, which can be made of high-strength alloy steel by casting or stamping. Its first arm segment is fixedly connected to the inner end of the fork arm 10, and the second arm segment forms a rotating pair with the base 9 via a pivot. This structure, by changing the spatial position of the hinge point, causes the folding trajectory of the fork arm 10 to produce a three-dimensional spatial offset. The hinge between the piston rod end and the rod body of the L-shaped rocker arm 20 means that the end of the piston rod of the drive cylinder 16 is connected to the middle part of the L-shaped rocker arm 20 via a pin, which can be a ball joint or universal joint structure, so that the direction of the hydraulic driving force forms a non-perpendicular angle with the rocker arm's motion plane, thereby converting the linear thrust into the rotational torque of the rocker arm.

[0080] Specifically, the fork arm 10 achieves dual rotational freedom through the L-shaped rocker arm 20. When the hydraulic drive unit pushes the piston rod, the L-shaped rocker arm 20 rotates around the hinge point of the base 9, causing the fork arm 10 to move along a compound trajectory. This trajectory allows the fork arm 10 to fold its front end to near the vehicle's centerline when fully folded, effectively reducing lateral space occupation. The hydraulic drive unit's design acting on the L-shaped rocker arm 20 amplifies the driving torque through leverage, resulting in a greater folding driving force under the same hydraulic pressure, while reducing the cylinder stroke requirement. Through the above technical solution, this application achieves efficient folding and unfolding of the fork arm 10 in narrow spaces, and its compound motion trajectory allows the folded fork arm 10 to completely avoid obstacles on both sides of the vehicle. The effective transmission of hydraulic driving force enables the fork arm 10 to maintain stable folding action even under load, avoiding the jamming phenomenon caused by insufficient driving force in traditional structures. The compact layout after the fork arms are folded down reduces the overall width of the forklift to 65% of its original size, meeting the requirements for passage in extremely narrow spaces such as inside train carriages.

[0081] exist Figure 5-7 In the illustrated scheme, the fork assembly 8 also includes a second sensor 21 for detecting whether the goods have reached the correct fork position, and a third sensor 22 for detecting whether the fork tip has touched an obstacle.

[0082] The second sensor 21 is mounted on an L-shaped rocker arm 20 or fork arm 10 on one side and is connected to a baffle mechanism 23 that can be touched by the goods. The second sensor 21 is a detection unit that detects the forklift status through mechanical triggering, specifically using a limit switch or micro switch. The baffle mechanism 23 is composed of a spring-loaded hinged metal plate. When the goods contact the baffle, it pushes the metal plate to rotate and triggers a sensor signal, thereby determining whether the goods have entered the preset forklift range. Specifically, when the fork arm 10 extends into the bottom of the goods, the goods contact the baffle mechanism 23 and push it to rotate, triggering the second sensor 21 to generate a signal indicating that the goods have reached the correct forklift position. At this time, the hydraulic drive unit stops operating, and the fork arm 10 maintains its current position to complete the forklift.

[0083] The third sensor 22 is a contact or photoelectric sensor with a buffer rebound structure, located at the front end of the fork arm 10. The third sensor 22 is a detection device used to detect obstacles at the front end of the fork, specifically implemented as a contact limit switch with an elastic rubber sleeve or a photoelectric sensor with a flexible support. The buffer rebound structure absorbs the impact force of a collision through a spring or elastic body, preventing damage to the sensor due to rigid contact. Specifically, when the front end of the fork contacts a low obstacle during its movement, the buffer rebound structure of the third sensor 22 deforms under pressure, triggering an alarm signal and immediately stopping the fork movement to prevent further collisions. While contact sensors directly sense obstacles through physical contact, photoelectric sensors achieve non-contact detection through beam interruption.

[0084] Through the above technical solution, this application can accurately determine whether the goods are in the correct fork position, avoiding the risk of forklift failure or tipping due to goods deviation. The timely detection and action stop function of obstacles at the fork tip significantly reduces the probability of collisions in confined spaces, improving the safety and operational efficiency of AGV forklifts in complex environments.

[0085] exist Figure 4 In the scheme shown, the mast part 2 also includes a fourth sensor 24 for detecting the lateral position of the built-in side shifter 6, a height sensor 25 for detecting the lifting height of the fork carriage 5, and a tilt sensor for detecting the tilt angle of the fork carriage 5.

[0086] The fourth sensor 24 has its cable end fixed to the moving part of the built-in side-shifting frame 6 via sensor bracket II 27, and its main body fixed to the fork carriage 5 via sensor bracket I 28. The fourth sensor 24 is a device that detects the lateral movement of the built-in side-shifting frame 6 using a cable-operated displacement measuring device, which can be implemented using a cable encoder or a cable potentiometer. The connection between the cable end and the moving part directly reflects the real-time position change of the side-shifting frame 6, while the main body being fixed to the non-moving part of the fork carriage 5 avoids errors caused by frame swaying during measurement. Specifically, the cable end of the fourth sensor 24 is connected to the moving part of the built-in side-shifting frame 6 via sensor bracket II 27. When the side-shifting frame 6 moves laterally, the cable is stretched or contracted, and the sensor body is fixed to the fork carriage 5 via sensor bracket I 28, converting the displacement into an electrical signal output.

[0087] The height sensor 25 is fixed to the upper side of the mast body 4 via sensor bracket I 28, and its cable end is fixed to the fork carriage 5 via sensor bracket II. The height sensor 25 is a device that detects the lifting height of the fork carriage 5 through a cable-driven linear displacement sensor, which can be implemented using a cable-driven displacement sensor or a magnetostrictive sensor. The connection between the cable end and the fork carriage 5 converts the lifting motion into a linear displacement signal, and fixing the main body to the upper side of the mast body 4 eliminates measurement interference caused by the tilting of the fork carriage 5. Specifically, the cable end of the height sensor 25 is connected to the fork carriage 5 via sensor bracket II. When the fork carriage 5 rises or falls, the change in cable length is detected by the sensor body, which is fixed to the upper side of the mast body 4 via sensor bracket I 28 to ensure a stable measurement reference.

[0088] The tilt sensor is fixed to a non-tilting component of the fork carriage 5, and its lever moves with the tilting portion of the fork carriage 5. The tilt sensor is a device that detects the tilt angle of the fork carriage 5 through a mechanical lever linked to a rotating component; it can be implemented using an angle encoder or a tilt sensor. The sensor body is fixed to the non-tilting component to isolate it from the influence of movements in other directions. The linkage structure between the lever and the tilting component converts angle changes into mechanical displacements that the sensor can recognize. Specifically, the lever of the tilt sensor is mechanically connected to the tilting portion of the fork carriage 5. When the fork carriage 5 tilts, the lever drives the internal mechanism of the sensor to generate an angle signal.

[0089] Through the above technical solutions, this application solves the problems of poor cargo handling stability and low operational safety caused by insufficient detection accuracy of fork lateral displacement, lifting height, and tilt angle when AGV forklifts operate in confined spaces. The split-mount structure of the lateral displacement sensor enables accurate measurement of lateral displacement, avoiding the cumulative errors of traditional gear transmission devices; the wire-type measurement method of the height sensor 25 directly converts lifting motion into a linear signal, eliminating the influence of environmental interference on the detection results; the lever linkage structure of the tilt sensor isolates non-tilting motion interference, ensuring the accuracy of angle detection. The collaborative work of multiple sensors provides a reliable data foundation for the precise control of the fork mechanism, thereby improving the stability of cargo handling and the safety of the operation process.

[0090] like Figure 1-3 As shown, the sensor system includes a top sensing radar 13, a rear obstacle avoidance radar 14, and symmetrically arranged side obstacle avoidance radars 15.

[0091] The top-mounted sensing radar 13 uses a millimeter-wave radar module, fixed to the top crossbeam of the mast via an adjustable-angle bracket. It covers the high-altitude area in front of the forks. The top-mounted sensing radar 13 scans the high space of the rack, sensing obstacles in front of the forklift and simultaneously using the robot's laser sensors to scan the surrounding environment. It combines laser point cloud data with the robot's current position, using computation and optimization algorithms to construct a real-time environmental map and estimate the robot's precise position within the map. The rear obstacle avoidance radar 14 is mounted at the end of a Z-shaped bracket on the lower rear side of the vehicle. The radar beam is tilted downwards at 15-25 degrees to detect obstacles near the ground at the rear of the vehicle. The side obstacle avoidance radars 15 are symmetrically mounted on the inner sides of the side skirts, with the radar detection surface facing downwards towards the sides of the vehicle. The horizontal coverage area of ​​the beam exceeds the width of the vehicle. This radar system employs a layered layout, combining high-mounted and low-mounted radars, eliminating blind spots near the ground in traditional solutions and improving obstacle recognition capabilities in complex environments. The multi-layered radar layout creates a blind-spot-free detection environment, avoiding the risk of collisions with low-lying obstacles.

[0092] In a specific implementation, the sensor system also includes a top radar bracket 29 for mounting the top sensing radar 13 and a rear radar bracket 30 for mounting the rear obstacle avoidance radar 14. The rear radar bracket 30 has a Z-shaped structure, with one end set on the top surface of the vehicle body 1 and the rear obstacle avoidance radar 14 set on the other end of the rear radar bracket 30. The top surface of the vehicle body 1 is sloped so that the detection surface of the rear obstacle avoidance radar 14 is tilted downwards and backwards. The Z-shaped structure of the rear radar bracket 30 refers to a three-dimensional support frame composed of three bent plates, which can be achieved by welding stamped steel plates. The first section is fixedly connected to the top surface of the vehicle body, the middle section extends upwards to form an obstacle avoidance space, and the last section extends horizontally to the rear of the vehicle body. This structure avoids interference from vehicle body components through spatial folding, providing a cantilever mounting position for the radar. The sloped top surface of the vehicle body 1 refers to a sloped surface in the upper rear area of ​​the vehicle body, which can be achieved by casting a 5°-15° tilt angle at the top of the frame 32. The slope causes the end of the radar bracket mounted on it to naturally tilt downwards, causing the radar detection surface to face the rear and lower area.

[0093] Specifically, the top radar bracket 29 is bolted to the top crossbeam of the mast, and the top sensing radar 13 is mounted on the top of its vertical support rod. The first section of the rear radar bracket 30 is fixed to the front end of the sloping roof surface of the vehicle body via a flange, the middle section bends upward and extends, and the last section extends horizontally to the rear of the vehicle. The rear obstacle avoidance radar 14 is fixed to the end mounting surface via adjusting bolts. The geometric fit between the sloping roof surface and the Z-shaped bracket creates a 15°-30° rearward downward tilt angle for the radar detection surface, covering the ground area within 1 meter behind the rear of the vehicle. The radar beam passes through the avoidance window formed by the middle section of the bracket, avoiding obstruction by the vehicle body itself. At the same time, the cantilever structure of the Z-shaped bracket keeps the radar body away from the vehicle vibration source. Through the above technical solution, this application achieves precise adjustment of the detection angle of the rear obstacle avoidance radar 14, expanding the detection range of ground obstacles behind the vehicle body. The three-dimensional structural design of the Z-shaped bracket effectively avoids spatial interference from internal vehicle components, ensuring a smooth radar beam transmission path. The synergistic effect of the sloping roof surface and the bracket shape allows the radar to achieve the optimal detection tilt angle within a limited installation space, solving the near-ground blind spot problem caused by the low installation position of traditional rear-mounted radars. The rigid connection structure of the bracket reduces the impact of vehicle vibration on radar measurement accuracy and improves perception stability under complex operating conditions.

[0094] In a further embodiment, the system includes multiple cameras, comprising a front-view camera 311, a side-view camera 312, and a rear-view camera 313. The front-view camera 311 is mounted at the end of the mast section 2, facing forward of the forks. The side-view cameras 312 are mounted on the left and right sides of the vehicle body section 1, facing the forks and the side areas of the vehicle body. The rear-view camera 313 is mounted at the rear of the vehicle body section 1, facing the rear of the vehicle body. The front-view camera 311 is an image acquisition device mounted at the end of the mast and facing forward; it can be implemented using a wide-angle lens camera. Its installation position is directly in front of the fork operating path, used to capture real-time visual information of the fork-picking area and the direction of travel. The side-view cameras 312 are image acquisition devices symmetrically distributed on both sides of the vehicle body; they can be implemented using industrial cameras with waterproof and dustproof housings. Their lenses cover the sides of the forks and the gap area between the vehicle body and obstacles, used to monitor the distance between the vehicle body and the side wall in narrow passages. The rearview camera 313 refers to an image acquisition device installed at the rear of the vehicle body. Specifically, it can be implemented using a low-light night vision camera with its lens tilted downwards and rearwards to capture visual data of the ground and low obstacles behind the vehicle body.

[0095] Specifically, the forward-facing camera 311, mounted at the end of the mast, directly faces the fork operating area, providing a real-time image of the pallet or goods in front when picking up goods, assisting the control system in judging the alignment accuracy between the forks and the goods. The side-facing cameras 312 are fixed on the left and right sides of the vehicle, their field of view covering the side area after the fork arms 10 are extended and the gap between the vehicle body and the side wall of the passageway. When the AGV moves inside a train car or container, it can calculate the distance between the vehicle body and the side wall in real time through image recognition algorithms to avoid scratches. The rear-facing camera 313 is installed at the rear of the vehicle, its lens angle optimized to capture obstacles on the ground behind it that are more than 10 centimeters high, such as scattered goods or equipment. Image processing technology feeds the obstacle position back to the navigation system, and data fusion with the rear obstacle avoidance radar 14 improves reversing safety. The installation positions and field of view angles of the three cameras are systematically designed to ensure blind-spot-free visual coverage in the forward, side, and rear directions, while avoiding overlap or interference between the fields of view of different cameras. Through the above technical solution, this application solves the problem of blind spots in environmental perception caused by unreasonable sensor layout in narrow spaces, especially in the detection of low obstacles near the ground, sides, and rear of the vehicle. By integrating multi-dimensional visual coverage and sensor data, it achieves comprehensive monitoring of the working environment. The forward-looking camera 311 provides visual guidance for precise forking of goods, the side-looking camera 312 effectively eliminates the detection blind spots between the vehicle body and the side wall, and the rear-looking camera 313 compensates for the limitations of traditional obstacle avoidance radar in detecting low obstacles on the ground. The coordinated operation of these three cameras significantly improves the safety and control accuracy of AGVs in extremely narrow spaces.

[0096] like Figure 1-4 As shown, the vehicle body 1 includes a one-piece cast frame 32, a front end 33 connected to the frame 32, a drive wheel assembly 34 mounted on the front end 33, a steering wheel assembly 35 mounted on the frame 32, a battery pack 36, and a hydraulic pump assembly 37. The frame 32 adopts a monolithic casting structure, integrating a battery mounting area, a front end mounting area 39, a controller mounting area, and a steering axle mounting area. The battery mounting area has a downwardly recessed battery placement groove 42. The front end mounting area 39 is located below and in front of the battery groove 42. The controller mounting area is recessed inward from the rear of the frame 32 to form a closed chamber. The steering axle mounting area adopts a downwardly opening through-type cavity structure. The internal cables of each functional area are connected through cable holes 47. The one-piece cast frame 32 refers to a monolithic structure formed by an integral casting process, specifically using an aluminum alloy die-casting process. During the casting process of the frame 32, the counterweight function is achieved by adjusting the material thickness distribution in different areas. The battery placement groove 42 refers to the recessed space formed on the surface of the frame 32. Specifically, the groove contour can be formed using an in-mold molding process, ensuring that the top of the battery assembly 36 is flush with the surface of the frame 32 after insertion. The steering axle mounting cavity 46 refers to the through-channel extending downwards from the rear of the frame 32, allowing the steering wheel assembly 35 to be positioned at the lower end of the frame 32 after installation. The cable passage hole 47 refers to the cable channel provided inside the cast frame 32. Specifically, pre-fabricated channels combined with sealing rings can be used to connect cables between different chambers.

[0097] Specifically, by designing the frame 32 as a one-piece cast structure, the splicing gaps and weld stress concentration problems of traditional welded frames are eliminated. Simultaneously, the casting process directly forms functional areas such as the battery recess 42 and controller chamber 43 within the frame 32. The battery assembly 36, embedded in the recess 42, forms a sunken installation, effectively lowering the vehicle's center of gravity. The front mounting area 39 and the battery recess 42 form a front-lower-rear-upper spatial layout, allowing the drive wheel assembly 34 and battery assembly 36 to overlap longitudinally, shortening the front overhang. The controller mounting cavity 43 forms a closed protective space through an inward recess at the rear of the frame 32, preventing the control components from being exposed to the external environment. The steering axle mounting cavity 46 adopts a through-type design, allowing the steering wheel assembly 35 to be completely built into the bottom of the frame 32, eliminating the protruding structure of traditional externally mounted steering axles. The cable routing holes 47 between the functional areas form internal cable channels, enabling integrated routing of power and signal lines. Through the above technical solutions, this application achieves a compact design of the vehicle body structure, solving the technical problems of excessive size and complex wiring layout in traditional split-type frames. The recessed installation of the battery pack 36 lowers the overall vehicle center of gravity, improving vehicle stability. The enclosed structure of the controller chamber 43 enhances the protection level of electronic components, preventing dust and moisture corrosion. The built-in installation of the steering axle reduces the lateral dimensions of the vehicle body, improving maneuverability in narrow spaces. The internal channel formed by the cable guide hole 47 reduces the risk of external cable exposure, improving equipment reliability. The integral cast frame 32, through optimized material distribution, replaces independent counterweights, reducing the overall vehicle weight while ensuring load-bearing capacity.

[0098] In a further embodiment, the frame 32 has air inlet holes 48 cast on both sides, communicating with the controller mounting cavity 43. Air inlet plates 49 are installed at the air inlet holes 48. The air inlet holes 48 refer to the perforated structures on both sides of the frame 32, which can be achieved using stamping or casting processes. They connect with the controller mounting cavity 43 to form an airflow channel, promoting heat dissipation for electronic components. The air inlet plates 49 can adopt a mesh or louvered structure, allowing airflow while preventing the entry of foreign objects. Specifically, the air inlet holes 48 and air inlet plates 49 on both sides of the frame 32 combine to form a forced convection cooling channel. When the vehicle is running, external airflow enters the controller mounting cavity 43 through the air inlet plates 49, carrying away the heat generated by the electronic components.

[0099] The side of the frame 32 has a charging component mounting cavity 50 cast in it. The charging component mounting cavity 50 is connected to the battery placement groove 42 through a charging cable routing hole 51. An automatic charging plate assembly 52 is installed inside the charging component mounting cavity 50. The charging component mounting cavity 50 refers to the recessed area cast into the side of the frame 32, which can be integrally formed using a cavity mold for centralized installation of the automatic charging plate assembly 52. ​​The charging cable routing hole 51 connects to the battery placement groove 42 through pre-embedded pipes or slots, achieving physical isolation and path optimization of the charging circuit. Specifically, the charging component mounting cavity 50 and the battery groove 42 are directly connected through the routing hole 51, eliminating the need for the charging circuit to bypass the frame 32 structure, shortening the wiring distance and avoiding intersections with hydraulic lines.

[0100] The frame 32 above the battery mounting area has an inwardly recessed front panel mounting cavity 53, which is connected to the controller mounting cavity 43. The front panel mounting cavity 53 refers to the maintenance interface area formed by the inward recess at the front of the frame 32. Specifically, it is connected to the controller mounting cavity 43 through a casting process, facilitating operator maintenance of the controller. The recess depth can be set to allow tools to be inserted. The front panel assembly is installed within the front panel mounting cavity 53 and integrates an external charging port, voice broadcast, and antenna. The recessed structure of the front panel mounting cavity 53 provides an operating window for controller maintenance, eliminating the need to disassemble the frame 32 housing during maintenance.

[0101] A mounting base plate 54 is cast inside the steering axle mounting cavity 46, dividing the steering axle mounting cavity 46 into an upper steering motor mounting cavity 55 and a lower steering wheel cavity 56. The rear axle adapter plate 57 of the steering wheel assembly 35 is fixed to the mounting base plate 54. The mounting base plate 54 refers to a partition structure cast inside the steering axle mounting cavity 46, which can be integrally cast with the main body of the frame 32 using reinforcing ribs, used to separate the movement space of the steering motor and the steering wheel. The rear axle adapter plate 57 is fixed to the upper surface of the base plate 54 by bolts or welding, forming a rigid connection. The mounting base plate 54 inside the steering axle mounting cavity 46 separates the steering motor and steering wheel into independent chambers, and the rigid fixing method of the rear axle adapter plate 57 can effectively suppress torsional deformation during steering.

[0102] Through the above technical solutions, this application solves the problem of heat dissipation difficulties in traditional vehicle frames, and achieves active heat dissipation by connecting the air inlet vent 48 with the controller cavity 43; optimizes the layout of the charging circuit to avoid the risk of wire entanglement and wear; simplifies the maintenance operation process of the controller through the front panel mounting cavity 53; and the rigid fixing structure of the mounting base plate 54 effectively suppresses the vibration and deformation of the steering mechanism and improves the vehicle's motion accuracy.

[0103] like Figure 2-3As shown in Figure 12, a front-end 33 is connected to the front-end mounting area 39. The front-end 33 is located below the front side of the battery placement groove 42, and the hydraulic pump assembly 37 is mounted on the front-end 33. A front cover 58 covers the front-end mounting area 39 and the battery mounting area of ​​the frame 32, enclosing the battery assembly 36 and the hydraulic pump assembly 37 inside. The front-end mounting area 39 refers to the area below the front side of the frame 32 used to fix the front-end 33. Specifically, it can be achieved by casting a groove structure with mounting holes. This area and the battery placement groove 42 are staggered vertically to reduce space occupation. The front cover 58 refers to the protective shell covering the front area of ​​the frame 32. Specifically, it can be achieved by using a split, detachable metal plate. Its edges are connected to the frame 32 by clips for quick installation and removal, and it is used to seal the battery assembly 36 and the hydraulic pump assembly 37. Specifically, the front hood 33 is positioned below the front side of the battery mounting recess 42, allowing the hydraulic pump assembly 37 to be directly fixed to the front hood mounting area 39, avoiding spatial interference with the rear battery assembly 36. The front cover 58 completely covers the front hood mounting area 39 and the battery mounting area, forming a closed space to hide hydraulic lines and battery cables, preventing external contaminants from entering.

[0104] The controller mounting area and steering axle mounting area of ​​the frame 32 are covered by a rear cover 59. The rear cover 59 is used to house the AGV control component 44, the vehicle control component 45, and the steering motor of the steering wheel device 35. The rear cover 59 is a protective shell covering the rear area of ​​the frame 32, which can be implemented using an engineering plastic shell with heat dissipation holes. It has cable fixing slots inside to isolate the steering motor from the control components. Specifically, the rear cover 59 independently covers the controller mounting area and the steering axle mounting area, placing the AGV control component 44 and the steering motor in different chambers to reduce electromagnetic interference. The staggered layout of the battery placement groove 42 and the front mounting area 39 of the frame 32, combined with the partitioned coverage of the front and rear covers, keeps the external contour of the vehicle body smooth and reduces protruding parts.

[0105] Through the above technical solutions, this application solves the problems of large size and complex wiring caused by the dispersed nature of vehicle body components. The vertical arrangement of the battery assembly 36 and the hydraulic pump assembly 37 reduces horizontal space occupation, while the partitioned coverage of the front cover 58 and the rear cover 59 achieves physical protection for critical components and concealment of wiring. The removable cover design allows for independent maintenance of the battery, hydraulic system, or control components without the need for complete vehicle body disassembly. The smoothing of the vehicle body's external contours reduces the risk of scraping when turning in narrow spaces.

[0106] In summary, the intelligent AGV forklift and its sensor system and frame structure provided in this application solve the problems of large size and many blind spots of traditional AGV forklifts through the integrated frame 32 design, foldable fork assembly 8 and multi-dimensional sensor layout. It has the advantages of compact structure, accurate perception and adaptability to the needs of narrow space operation.

[0107] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0108] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. An intelligent AGV forklift for use in confined spaces, comprising a body section (1) and a mast section (2), and a sensor system disposed on the body section (1) and the mast section (2); characterized in that: - The mast part (2) includes a mast body (4), a fork carriage (5) that is lifted and installed on the mast body (4), and a built-in side shifter (6) installed on the fork carriage (5); a backrest (7) and two sets of independent fork assemblies (8) are fixedly installed on the built-in side shifter (6); - The fork assembly (8) includes a base (9), fork arms (10), a hydraulic drive unit and a position detection unit; the base (9) is fixed on the built-in side shifter (6), the fork arms (10) are hinged to the base (9), and the hydraulic drive unit connects the base (9) and the fork arms (10) to drive the fork arms (10) to fold and unfold relative to the base (9); The position detection unit is used to detect the folded position and unfolded position of the fork arm (10); - The sensor system includes: - A top sensing radar (13) is mounted on top of the gantry section (2) via a bracket; - A rear obstacle avoidance radar (14) is mounted on the lower rear side of the vehicle body part (1); - Two side obstacle avoidance radars (15) are symmetrically installed on the lower left and right sides of the vehicle body part (1).

2. The intelligent AGV forklift according to claim 1, characterized in that: The hydraulic drive unit includes at least one drive cylinder (16) and a control valve group. The cylinder body end of the drive cylinder (16) is hinged to the base (9), and its piston rod end is hinged to the fork arm (10). The control valve group is connected to the drive cylinder (16) through an oil circuit.

3. The intelligent AGV forklift according to claim 1, characterized in that: The position detection unit includes a first sensor (18) disposed on the rotation path of the fork arm (10) for detecting the folded position and unfolded position of the fork arm (10); the first sensor (18) is a limit switch, proximity switch or angle sensor, which is fixedly installed on the base (9); the fork arm (10) is provided with a trigger (19) that cooperates with the first sensor (18).

4. The intelligent AGV forklift according to claim 1, characterized in that: The inner end of the fork arm (10) is hinged to the base (9) via an L-shaped rocker arm (20); one end of the L-shaped rocker arm (20) is fixedly connected to the inner end of the fork arm (10), and the other end is hinged to the base (9); the piston rod end of the drive cylinder (16) of the hydraulic drive unit is hinged to the rod body of the L-shaped rocker arm (20).

5. The intelligent AGV forklift according to claim 4, characterized in that: It also includes a second sensor (21) for detecting whether the goods have reached the correct fork position, and a third sensor (22) for detecting whether the fork tip has touched an obstacle; - The second sensor (21) is disposed on the L-shaped rocker arm (20) or the fork arm (10) on one side and is connected to a baffle mechanism (23) that can be touched by the goods; - The third sensor (22) is a contact or photoelectric sensor with a buffer rebound structure, and is located at the front end of the fork arm (10).

6. The intelligent AGV forklift according to claim 1, characterized in that: It also includes a fourth sensor (24) for detecting the lateral position of the built-in side shifter (6), a height sensor (25) for detecting the lifting height of the fork carriage (5), and a tilt sensor for detecting the tilt angle of the fork carriage (5); - The pull wire end of the fourth sensor (24) is fixed to the moving part of the built-in side shift frame (6) through the sensor bracket II (27), and its main body is fixed to the fork carriage (5) through the sensor bracket I (28); - The main body of the height sensor (25) is fixed to the upper side of the mast body (4) by the sensor bracket I (28), and its pull wire end is fixed to the fork carriage (5) by the sensor bracket II; - The tilt sensor is fixed on a non-tilting part of the fork carriage (5), and its paddle moves with the tilting part of the fork carriage (5).

7. The intelligent AGV forklift according to claim 1, characterized in that: The sensor system also includes a top radar bracket (29) for mounting the top sensing radar (13) and a rear radar bracket (30) for mounting the rear obstacle avoidance radar (14); the rear radar bracket (30) has a Z-shaped structure, with one end set on the top surface of the vehicle body part (1) and the rear obstacle avoidance radar (14) set on the other end surface of the rear radar bracket (30); the top surface of the vehicle body part (1) is a slope so that the detection surface of the rear obstacle avoidance radar (14) is tilted downwards and backwards.

8. The intelligent AGV forklift according to claim 1 or 7, characterized in that: The sensor system also includes multiple cameras, including a front-view camera (311), a side-view camera (312), and a rear-view camera (313). - The forward-facing camera (311) is mounted at the end of the mast portion (2) and faces the front of the forks; - The side-view camera (312) is installed on the left and right sides of the vehicle body (1), facing the forks and the side area of ​​the vehicle body; - The rearview camera (313) is mounted at the rear of the vehicle body part (1) and faces the rear of the vehicle body.

9. The intelligent AGV forklift according to claim 1, characterized in that: The vehicle body (1) includes an integral cast frame (32), a front end (33) connected to the frame (32), a drive wheel assembly (34) mounted on the front end (33), a steering wheel assembly (35) mounted on the frame (32), a battery assembly (36), and a hydraulic pump assembly (37); - The frame (32) is a single-piece structure integrally cast and has a counterweight function; the frame (32) has a battery mounting area, a front mounting area (39), a controller mounting area and a steering axle mounting area; - The battery mounting area is cast with a downwardly recessed battery placement groove (42), the battery assembly (36) is installed in the battery placement groove (42), and the front mounting area (39) is located below the front side of the battery placement groove (42); - The controller mounting area includes a controller mounting cavity (43) formed by an inward recess at the rear of the chassis; the AGV control assembly (44) and the vehicle control assembly (45) are located within the controller mounting cavity (43); - The steering axle mounting area is formed by a steering axle mounting cavity (46) that opens downward and backward from the rear of the frame and extends through the bottom of the frame to mount the steering wheel assembly (35); - The battery placement groove (42) is connected to the controller mounting cavity (43) and the steering axle mounting cavity (46) through the wire hole (47).

10. The intelligent AGV forklift according to claim 9, characterized in that: - The frame (32) has air inlet holes (48) cast on both sides that are connected to the controller mounting cavity (43), and an air inlet plate (49) is installed at the air inlet holes (48); - The side of the frame (32) is cast with a charging component mounting cavity (50), and the charging component mounting cavity (50) is connected to the battery placement groove (42) through a charging cable routing hole (51). An automatic charging plate assembly (52) is installed in the charging component mounting cavity (50). - The frame portion above the battery mounting area is cast with an inwardly recessed front panel mounting cavity (53), which is connected to the controller mounting cavity (43); - The steering axle mounting cavity (46) is filled with a mounting reference plate (54), which divides the steering axle mounting cavity (46) into an upper steering motor mounting cavity (55) and a lower steering wheel cavity (56); the rear axle adapter plate (57) of the steering wheel device (35) is fixed on the mounting reference plate (54).

11. The intelligent AGV forklift according to claim 9, characterized in that: The front mounting area (39) is connected to the front (33), the front (33) is located below the front side of the battery placement groove (42), and the hydraulic pump assembly (37) is mounted on the front (33); - The front mounting area (39) and battery mounting area of ​​the frame (32) are covered by a front cover (58), which encloses the battery assembly (36) and the hydraulic pump assembly (37) inside; - The controller mounting area and steering axle mounting area of ​​the frame (32) are covered with a rear cover (59), which is used to house the AGV control component (44), the vehicle control component (45) and the steering motor of the steering wheel device (35).

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