An unmanned fork truck

Abstract

The application discloses an unmanned forklift, which comprises a vehicle body, a control system arranged in the vehicle body, a fork arm installed at the rear of the vehicle body, a portal assembly connected with the vehicle body and driving the fork arm to move horizontally relative to the vehicle body, a sensor comprising a front obstacle avoidance sensor, a rear obstacle avoidance sensor and a posture recognition camera for detecting the posture of a tray in front of the fork arm, the rear obstacle avoidance sensor comprising a rear obstacle avoidance radar and a fork arm protection assembly, the fork arm protection assembly comprising a tine protection assembly and a root protection assembly, the tine protection assembly being located at the tine of the fork arm, the root protection assembly being located at the root of the fork arm, and the posture recognition camera being located on the portal assembly, and a control system electrically connected with the sensor and receiving detection signals from the sensor. By reasonably arranging the positions of various sensors, the unmanned forklift can realize good sensing and control of the external environment and the state performance of the forklift, and ensure the safety of forklift operation.

Description

Technical Field

[0001] This invention relates to the field of intelligent warehousing technology, and in particular to an unmanned forklift. Background Technology

[0002] Forklifts are vehicles that use forks as lifting devices to lift goods to a certain height and transport them. Given the narrow aisle spaces in some application scenarios, traditional manual forklifts, limited by their size and the operator's skill level, struggle to ensure safe operation within aisles. Therefore, automated forklifts have become the mainstream in the field of smart warehousing. In smart warehousing, to ensure the safe operation of automated forklifts, various safety sensors are typically installed, and the feedback from these sensors is used as the basis for driving decisions. However, currently, comprehensive safety protection solutions for the entire sensor layout of automated forklifts are still scarce in the industry.

[0003] Existing AGV (Automated Guided Vehicle) and AMR (Autonomous Mobile Robots) unmanned forklifts typically employ a single type of sensor arrangement. Each type of sensor has its advantages and disadvantages. For example, LiDAR offers strong spatial resolution but is significantly affected by weather conditions, while photoelectric sensors, although more adaptable to various environments, have relatively low spatial resolution. Furthermore, current sensor placement practices are inadequate. Inappropriate sensor placement not only increases the cost of the forklift but also affects the obstacle avoidance safety of the entire unmanned forklift. Summary of the Invention

[0004] The main objective of this invention is to provide an unmanned forklift that improves the arrangement of multiple types of sensors to avoid the problems associated with unmanned forklifts.

[0005] To achieve the above objectives, the present invention proposes an unmanned forklift, comprising: a vehicle body, wherein a control system is disposed within the vehicle body; a fork arm, wherein the fork arm is mounted at the rear of the vehicle body; a mast assembly, wherein the mast assembly is connected to the vehicle body and drives the fork arm to move horizontally relative to the vehicle body; and sensors, wherein the sensors are communicatively connected to the control system, the sensors including a front obstacle avoidance sensor, a rear obstacle avoidance sensor, and an attitude recognition camera for detecting the pallet position in front of the fork arm, the rear obstacle avoidance sensor including a rear obstacle avoidance radar and a fork arm protection assembly, the fork arm protection assembly including a tooth tip protection assembly and a tooth root protection assembly, the tooth tip protection assembly being located at the tooth tip of the fork arm, the tooth root protection assembly being located at the tooth root of the fork arm, and the attitude recognition camera being located on the mast assembly.

[0006] Optionally, the unmanned forklift also includes a central control unit mounted on the top of the vehicle body, and the top of the central control unit is equipped with a positioning lidar for real-time monitoring of the relative position of the unmanned forklift throughout the entire dispatch space.

[0007] Furthermore, the forward obstacle avoidance sensor includes a forward stereo obstacle avoidance camera and a forward obstacle avoidance radar, with the forward stereo obstacle avoidance camera rotatably connected to the central control assembly.

[0008] Furthermore, two front obstacle avoidance radars are provided, one on the left and one on the right side of the bottom front of the vehicle body, respectively. The front obstacle avoidance sensors form a first detection area. When an obstacle comes into contact with the first detection area, the front obstacle avoidance sensors send a first detection signal to the control system. The control system obtains the status of the obstacle in front of the vehicle body based on the first detection signal.

[0009] Optionally, the tooth cusp protection component includes a tooth cusp photoelectric sensor and a tooth cusp camera, and the tooth cusp protection component is horizontally disposed in front of the tooth cusp of the fork arm; the tooth root protection component includes a tooth root photoelectric sensor, and the tooth root protection component is horizontally disposed in front of the tooth root of the fork arm.

[0010] Furthermore, the rear obstacle avoidance sensor forms a second detection area along the rear direction of the vehicle body; when an obstacle comes into contact with the second detection area, the rear obstacle avoidance sensor sends a second detection signal to the control system, and the control system obtains the situation of the obstacle behind the vehicle body based on the second detection signal.

[0011] Optionally, the gantry assembly is provided with a height detection component for detecting the lifting state of the fork arm. The height detection component includes an upper limit switch for the fork arm, a lower limit switch for the fork arm, and a fork arm pull wire code for detecting the distance the fork arm moves upward.

[0012] Optionally, the control system includes a walking encoder and a steering encoder.

[0013] Optionally, the central control unit also includes an audio-visual prompting component, which includes a voice player, a parking light for projecting a safety area, and a tri-color light for indicating the vehicle status.

[0014] Optionally, the unmanned forklift also includes a passive protection component, which includes an emergency stop button and a safety contact edge for passive mechanical protection at the front of the vehicle body. The safety contact edge is fitted onto the bottom of the vehicle body, and the emergency stop button is located on the central control component.

[0015] This invention, by deploying multiple different types of sensors on an unmanned forklift and rationally arranging their installation positions, ensures 360° obstacle avoidance protection for the forklift, enabling it to flexibly perceive external environmental information and achieve safer control of the entire vehicle based on sensor data. Furthermore, by combining laser sensors, vision sensors, and photoelectric sensors, this invention maintains good adaptability to various operating environments, avoiding the influence of terrain and weather. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a diagram showing the connection relationships of the various components of the unmanned forklift of the present invention;

[0018] Figure 2 This is a schematic diagram of an angle from the first embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the first embodiment of the present invention from another angle;

[0020] Figure 4 This is a schematic diagram of the projection area of ​​the parking light of the present invention;

[0021] Figure 5 This is a schematic diagram of the first detection area according to the first embodiment of the present invention;

[0022] Figure 6 This is a schematic diagram of the second detection area according to the first embodiment of the present invention;

[0023] Figure 7 This is a schematic diagram of an angle from the second embodiment of the present invention;

[0024] Figure 8 for Figure 7 Enlarged view of point A;

[0025] Figure 9 This is a schematic diagram of the second embodiment of the present invention from another angle;

[0026] Figure 10 This is a schematic diagram of the first detection area according to the second embodiment of the present invention;

[0027] Figure 11 This is a schematic diagram of the second detection area according to the second embodiment of the present invention.

[0028] Explanation of icon numbers:

[0029] Vehicle body 1; Fork arm 2; Mast assembly 3; Chain 31; Fork arm upper limit switch 32; Fork arm lower limit switch 33; Attitude recognition camera 41; Front 3D obstacle avoidance camera 42; Front obstacle avoidance radar 43; Rear obstacle avoidance radar 44; Tooth tip photoelectric sensor 45; Tooth tip camera 46; Tooth root photoelectric sensor 47; Central control assembly 5; Control panel 51; Positioning lidar 52; Voice player 53; Parking lights 54; Tri-color lights 55; Projection area 56; Emergency stop button 57; Safety contact edge 58; First detection area 6; First protection area 61; Second protection area 62; Second detection area 7; Third protection area 71; Fourth protection area 72; Control system 8; Travel encoder 81; Steering encoder 82.

[0030] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0033] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, if the word "and / or" appears throughout the text, it means including three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0034] This invention proposes an unmanned forklift, see [link / reference]. Figure 1-3 The unmanned forklift includes a vehicle body 1, within which a control system is installed; a fork arm 2, mounted at the rear of the vehicle body 1; a mast assembly 3, connected to the vehicle body 1 and driving the fork arm 2 to move horizontally relative to the vehicle body 1; and sensors, communicatively connected to the control system. These sensors include a front obstacle avoidance sensor, a rear obstacle avoidance sensor, and an attitude recognition camera 41 for detecting the pallet position in front of the fork arm 2. The rear obstacle avoidance sensor includes a rear obstacle avoidance radar 44 and a fork arm protection assembly. The fork arm protection assembly includes a tooth tip protection assembly and a tooth root protection assembly. The tooth tip protection assembly is located at the tooth tip of the fork arm 2, and the tooth root protection assembly is located at the tooth root of the fork arm 2. The attitude recognition camera 41 is located on the mast assembly 3.

[0035] The posture recognition camera 41, acting as a visual sensor, uses AI detection to analyze the pallet's position and perform precise calculations before picking up the goods, then replans the route and retrieves the pallet. After picking up the goods, it can also monitor the actual position and posture of the pallet relative to the fork arms 2 in real time, thus preventing the goods from tipping over. Furthermore, the posture recognition camera 41 also has barcode and RFID identification capabilities.

[0036] In addition, the unmanned forklift has a double fork arm 2, which is a toothed fork structure. The tooth tip refers to the position of the front end of the toothed fork tooth, and the tooth root refers to the position of the end of the toothed fork tooth.

[0037] By strategically deploying multiple sensors on the unmanned forklift, 360° obstacle avoidance protection is ensured, enabling the forklift to flexibly perceive external environmental information and achieve safer control of the entire vehicle based on sensor data. Furthermore, this invention combines laser sensors, vision sensors, and photoelectric sensors, maintaining good adaptability to various operating environments and avoiding the influence of terrain and weather.

[0038] In the first embodiment, see Figure 2-3 The unmanned forklift includes a vehicle body 1, fork arms 2, a mast assembly 3, and sensors. The sensors include a front obstacle avoidance sensor, a rear obstacle avoidance sensor, and a posture recognition camera 41 for detecting the position and orientation of the pallet in front of the fork arms 2. A central control assembly 5 is also located on the top of the vehicle body 1, extending from the top of the vehicle body 1. The central control assembly 5 has multiple control panels 51 for human-machine interaction. The mast assembly 3 is movably connected to the rear of the vehicle body 1, and the mast assembly 3 drives the fork arms 2 to move up and down.

[0039] For details, see Figure 2The front obstacle avoidance sensor includes a front stereo obstacle avoidance camera 42 and two front obstacle avoidance radars 43. The front stereo obstacle avoidance camera 42 is rotatably connected to the top of the central control component 5 through a rotating shaft structure. The front stereo obstacle avoidance camera 42 is used for active stereo protection in the direction of the vehicle front. The two front obstacle avoidance radars 43 are located at the bottom of the vehicle body 1 in the direction of the vehicle front and are symmetrically arranged on both sides along the center line of the vehicle body 1.

[0040] Further, see Figure 5 The front 3D obstacle avoidance camera 42 has a horizontal viewing angle of 80° and a vertical viewing angle of 60°. Its installation position can detect suspended obstacles on the front of the vehicle, thus forming a first protection zone 61. The two front obstacle avoidance radars 43 are positioned to the left and right to achieve a 270° scan of the bottom of the front of the vehicle, thus forming a second protection zone 62. The first protection zone 61 and the second protection zone 62 together form a first detection zone 6. When an obstacle comes into contact with the first detection zone 6, the sensor sends a first detection signal to the control system. The control system obtains the situation of the obstacle in front of the vehicle body 1 based on the first detection signal, thus ensuring obstacle avoidance protection without blind spots in front.

[0041] In the first embodiment, see Figure 3 The rear obstacle avoidance sensor includes a rear obstacle avoidance radar 44 and a fork arm protection assembly. The rear obstacle avoidance radar 44 is located at the bottom of the mast assembly 3 and is used for active planar protection in the rear direction. The fork arm protection assembly consists of a tooth tip photoelectric sensor 45 located at the tooth tip of the fork arm 2 and a tooth root photoelectric sensor 47 located at the tooth root of the fork arm 2. The tooth tip photoelectric sensor 45 is located on the two fork arms 2, and there are two tooth root photoelectric sensors 47, which are respectively located on the two fork arms 2.

[0042] Further, see Figure 6 The rear-mounted 3D obstacle avoidance radar can perform a 270° scan of the rear bottom of the vehicle, thus forming a third protection zone 71 at the rear. Simultaneously, when the fork arm 2 is driven by the mast assembly 3, the lifting motion of the fork arm 2 allows the fork arm protection assembly to move in three-dimensional space along with the fork arm 2. Therefore, the two-dimensional scanning of the tooth tip photoelectric sensor 45 and the tooth root photoelectric sensor 47 can move vertically to obtain three-dimensional distance data of objects around the fork arm 2, thereby forming a fourth protection zone 72. The third protection zone 71 and the fourth protection zone 72 together form a second detection zone 7. When an obstacle contacts the second detection zone 7, the sensor sends a second detection signal to the control system. The control system obtains the status of obstacles in front of the vehicle body 1 based on the second detection signal, thus ensuring obstacle avoidance protection without blind spots at the rear.

[0043] In the first embodiment, see Figure 2 The top of the central control component 5 is equipped with a positioning lidar 52, which is used to monitor the relative position of the unmanned forklift in the entire scheduling space in real time. The positioning lidar 52 adopts the laser SLAM algorithm, which can accurately locate the unmanned forklift with higher resolution and a longer detection range, thereby ensuring the safe control of the unmanned forklift.

[0044] In the first embodiment, participants Figure 3 The driving mechanism of the mast assembly 3 is a hydraulic press combined with chain 31 traction, which can better drive the fork arm 2 to lift the goods. The mast assembly 3 is equipped with a height detection component for detecting the lifting state of the fork arm 2. The height detection component includes an upper limit switch for the fork arm (not shown in the figure), a lower limit switch for the fork arm (not shown in the figure), and a fork arm pull wire code (not shown in the figure) for detecting the distance of the fork arm 2 moving upward. The upper limit switch 32 and the lower limit switch 33 are used to detect and limit the highest and lowest positions of the fork arm 2, so as to more accurately perceive the state of the unmanned forklift itself and avoid accidents caused by the operation deviation of the unmanned forklift.

[0045] In the first embodiment, see Figure 4 The central control component 5 also includes an audio-visual prompting component, which includes a voice player 53, marker lights 54 for projecting safety areas, and tri-color lights 55 for indicating vehicle status. Specifically, the voice player 53 is located on the top of the central control component 5 and can remind and warn the vehicle body 1 of its operating status through voice playback. The marker lights 54 are located on the side of the central control component 5, and the number can be set to multiple. Multiple marker lights 54 form a projection area 56 to display the safety protection area of ​​the vehicle body 1. The tri-color lights 55 are located on the top of the central control component 5 and convey the current status of the vehicle body 1 through the color of the light: green indicates that the vehicle body 1 is operating normally, red indicates that the vehicle body 1 is not at the designated location or there is a malfunction of the vehicle body 1, and yellow indicates that the vehicle body 1 is under traffic control. The audio-visual prompting component can visualize the warning notification, thereby providing users with more intuitive reminders and warnings.

[0046] In the first embodiment, see Figure 1The unmanned forklift also includes a passive protection component, which includes an emergency stop button 57 and a safety edge 58 for passive mechanical protection at the front of the vehicle body 1. The safety edge 58 is fitted onto the bottom of the vehicle body 1, and the emergency stop button 57 is located on the central control component 5. Specifically, the safety edge 58 is made of flexible material and has a built-in anti-collision sensor. In certain situations, when the safety edge 58 has come into contact with an obstacle, it will notify the control system through its built-in anti-collision sensor, and the control system will control the forklift to stop urgently.

[0047] Furthermore, the control system is pre-set with a safety obstacle avoidance fusion algorithm. When the control system receives the first detection signal and the second detection signal from the sensor, the pre-set safety obstacle avoidance fusion algorithm will fuse all real-time data related to obstacle avoidance from the aforementioned obstacle avoidance lidar, obstacle avoidance photoelectric, stereo obstacle avoidance camera, anti-collision sensor, and upper management control system, and give the algorithm result to the forklift safety obstacle avoidance system according to a certain safety strategy. The forklift safety obstacle avoidance system sends the safety obstacle avoidance result to the forklift on-board control system through the vehicle communication system. The forklift on-board control system will control the forklift to complete the warning, deceleration, direct passage, optimal avoidance passage, fast passage, stopping and waiting, stopping, and emergency stopping operations.

[0048] In the second embodiment, see Figure 9-11 The rear obstacle avoidance sensor includes a fork arm protection assembly. This assembly comprises a tooth-point photoelectric sensor 45 and a tooth-point camera 46 positioned at the tooth tip of the fork arm 2, and a tooth-root photoelectric sensor 47 positioned at the tooth root of the fork arm 2. The tooth-point photoelectric sensor 45 and the tooth-point camera 46 are respectively mounted on the two fork arms 2, and their positions can be adapted as needed. Two tooth-root photoelectric sensors 47 are provided, each mounted on one of the two fork arms 2. The tooth-point photoelectric sensor 45 and the tooth-root photoelectric sensor 47 provide obstacle avoidance in front of the tooth tip and in front of the tooth root of the fork arm 2, forming a fifth protection zone. Simultaneously, a sixth protection zone is projected by the tooth-point camera 46. The fifth and sixth protection zones together constitute the second detection zone 7, thus ensuring obstacle avoidance protection without blind spots at the rear.

[0049] In the second embodiment, see Figure 7-8 The control system includes a travel encoder 81 and a steering encoder 82. The travel encoder 81 monitors and provides feedback on the actual number of rotations of the steering wheel motor of the unmanned forklift. The steering encoder 82 monitors and provides feedback on the magnitude and direction of the actual steering wheel angle. The steering encoder 82 is also equipped with a limit switch for centering the steering wheel. When the forklift body 1 maintains a constant turning angle while moving forward and backward, and its trajectory is approximately a straight line, the current turning angle is the center angle. By positioning this center angle, the forklift's travel trajectory can be made more precise.

[0050] In the second embodiment, see Figure 7-8 The driving mechanism of the mast assembly 3 is a hydraulic press traction. A height detection component for detecting the lifting state of the fork arm 2 is provided on the mast assembly 3. The height detection component includes an upper limit switch 32 and a lower limit switch 33. The upper limit switch 32 and the lower limit switch 33 are used to detect and limit the highest and lowest lifting positions of the fork arm 2, thereby more accurately sensing the state of the unmanned forklift itself and avoiding accidents caused by operational deviations of the unmanned forklift.

[0051] In the second embodiment, see Figure 7-9 The design of the forward obstacle avoidance sensor, the central control component 5, and the audio-visual prompt component is similar to that of the first embodiment. The corresponding process in the aforementioned method embodiment can be referred to, and will not be repeated here.

[0052] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An unmanned forklift, characterized in that, include: The vehicle body, and the control system is installed inside the vehicle body; A fork arm, which is mounted at the rear of the vehicle body; A mast assembly, which is connected to the vehicle body, and the mast assembly drives the fork arm to move horizontally relative to the vehicle body; as well as The sensor is communicatively connected to the control system. The sensor includes a front obstacle avoidance sensor, a rear obstacle avoidance sensor, and an attitude recognition camera for detecting the position of the pallet in front of the fork arm. The rear obstacle avoidance sensor includes a rear obstacle avoidance radar and a fork arm protection assembly. The fork arm protection assembly includes a tooth tip protection assembly and a tooth root protection assembly. The tooth tip protection assembly is located at the tooth tip of the fork arm, and the tooth root protection assembly is located at the tooth root of the fork arm. The attitude recognition camera is located on the gantry assembly. The unmanned forklift also includes a central control unit mounted on the top of the vehicle body, and the top of the central control unit is equipped with a positioning lidar for real-time monitoring of the relative position of the unmanned forklift in the entire dispatch space. The front obstacle avoidance sensor includes a front stereo obstacle avoidance camera and a front obstacle avoidance radar, and the front stereo obstacle avoidance camera is rotatably connected to the central control component; The front stereo obstacle avoidance camera has a horizontal field of view of 80° and a vertical field of view of 60°, which can detect suspended obstacles on the front of the vehicle, thereby forming the first protection zone. Two front obstacle avoidance radars are provided, which are respectively located on the left and right sides of the bottom front of the vehicle body, and can achieve a 270° scan of the bottom of the front of the vehicle, thereby forming a second protection zone. The tooth cusp protection component includes a tooth cusp photoelectric sensor and a tooth cusp camera. The tooth cusp protection component is horizontally positioned in front of the tooth cusp of the fork arm. The tooth root protection component includes a tooth root photoelectric sensor. The tooth root protection component is horizontally positioned in front of the tooth root of the fork arm. The rear obstacle avoidance radar can perform a 270° scan of the rear bottom of the vehicle, thereby forming a third protection zone at the rear. The fork arm is driven by the gantry assembly, enabling the tooth tip photoelectric sensor and the tooth root photoelectric sensor to obtain three-dimensional distance data of objects around the fork arm, thereby forming a fourth protective zone; The forward obstacle avoidance sensor forms a first detection area that includes the first protection area and the second protection area; When an obstacle comes into contact with the first detection area, the forward obstacle avoidance sensor sends a first detection signal to the control system, and the control system obtains the situation of the obstacle in front of the vehicle body based on the first detection signal. The rear obstacle avoidance sensor forms a second detection area that includes the third protection area and the fourth protection area; When an obstacle comes into contact with the second detection area, the rear obstacle avoidance sensor sends a second detection signal to the control system, and the control system obtains the situation of the obstacle behind the vehicle body based on the second detection signal.

2. The unmanned forklift according to claim 1, characterized in that, The gantry assembly is equipped with a height detection component for detecting the lifting and lowering state of the fork arm. The height detection component includes an upper limit switch for the fork arm, a lower limit switch for the fork arm, and a fork arm pull wire code for detecting the distance the fork arm moves upward.

3. The unmanned forklift according to claim 1, characterized in that, The control system includes a walking encoder and a steering encoder.

4. The unmanned forklift according to claim 1, characterized in that, The central control unit also includes an audio-visual prompting component, which includes a voice player, a marker light for projecting a safety area, and a tri-color light for indicating the vehicle status.

5. The unmanned forklift according to claim 1, characterized in that, The unmanned forklift also includes a passive protection component, which includes an emergency stop button and a safety edge for passive mechanical protection at the front of the vehicle body. The safety edge is fitted onto the bottom of the vehicle body, and the emergency stop button is located on the central control component.

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