Unmanned forklift control method, device, equipment and storage medium

Abstract

The present invention belongs to the field of AGV control technology, and discloses an unmanned forklift control method, device, equipment and storage medium. The present invention obtains cargo loading and unloading instructions, controls the steering angle of the steering wheel according to the cargo loading and unloading instructions, and makes the unmanned forklift travel along the target driving trajectory to the target position. When the unmanned forklift is detected to arrive at the target position, the fork arm is controlled to load and unload the cargo according to the cargo loading and unloading instructions. Compared with the prior art, the present invention obtains cargo loading and unloading instructions, determines the direction and angle of deflection of each steering wheel according to the cargo loading and unloading instructions, and controls and adjusts the deflection angle of each steering wheel of the unmanned forklift, so that the unmanned forklift can adjust its own posture within a relatively small range and go to the target position according to the path indicated by the instructions, thereby completing the loading and unloading of cargo.

Description

Technical Field

[0001] The present invention relates to the field of AGV control technology, and in particular to an unmanned forklift control method, device, equipment and storage medium. Background Art

[0002] With the maturity of unmanned forklift technology, more and more warehouse transportation has begun to use unmanned forklifts to replace manual labor for high-intensity cargo handling, which can improve the efficiency of cargo handling to a certain extent. However, traditional unmanned forklifts usually need to rely on laying guide devices to guide the unmanned forklifts. Unmanned forklifts require a relatively large space to complete movement or turning during the movement process. For warehouse environments with complex environments and small movable space, they cannot turn and move well.

[0003] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0004] The main purpose of the present invention is to provide an unmanned forklift control method, device, equipment and storage medium, aiming to solve the technical problem in the prior art that unmanned forklifts cannot turn and move well in a small space.

[0005] To achieve the above-mentioned object, the present invention provides an unmanned forklift control method, device, equipment and storage medium method, the method comprising the following steps:

[0006] Obtain cargo loading and unloading instructions;

[0007] Controlling the steering angle of the steering wheel according to the cargo loading and unloading instructions so that the unmanned forklift drives along the target driving trajectory to the target location;

[0008] When it is detected that the unmanned forklift arrives at the target position, the fork arm is controlled to load and unload the cargo according to the cargo loading and unloading instruction.

[0009] Optionally, controlling the steering angle of the steering wheel according to the cargo loading and unloading instruction so that the unmanned forklift drives along the target driving trajectory to the target position includes:

[0010] Obtaining a target driving trajectory of the unmanned forklift according to navigation information contained in the cargo loading and unloading instruction;

[0011] Obtaining the current location of the unmanned forklift;

[0012] The steering angle of the steering wheel is determined according to the target driving trajectory and the current position, so that the unmanned forklift can travel to the target position along the target driving trajectory.

[0013] Optionally, determining the steering angle of the steering wheel according to the target driving trajectory and the current position of the unmanned forklift includes:

[0014] Obtaining a reference point of the unmanned forklift, projecting the reference point onto the target driving trajectory, and obtaining a speed direction of the reference point;

[0015] Obtaining the tangent slope of the reference point at the current curve position according to the velocity direction;

[0016] Obtaining the curvature of the curve at the current position according to the tangent slope of the reference point at the current curve position;

[0017] The steering angle of the steering wheel is obtained according to the curvature of the current position curve.

[0018] Optionally, obtaining the steering angle of the steering wheel according to the curvature of the current position curve includes:

[0019] Establishing a vehicle coordinate system with the reference point as the coordinate origin, and acquiring corresponding coordinates of the steering wheel according to the relative position of the steering wheel and the reference point;

[0020] detecting the curvature of the current position curve;

[0021] When the curvature of the current position curve is not equal to a preset value, obtaining the rotation radius of the reference point and the rotation center coordinates of the reference point according to the curvature;

[0022] Obtaining the slope of the steering wheel rotation trajectory according to the rotation radius, the rotation center coordinates, the corresponding coordinates of the steering wheel and the tangent slope of the reference point at the current curve position;

[0023] The steering angle is calculated according to the slope of the steering wheel rotation trajectory.

[0024] Optionally, after detecting the curvature of the current position curve, the method further includes:

[0025] When the curvature of the current position curve is equal to a preset value, obtaining an angle between the velocity direction of the current reference point and the coordinate system;

[0026] The steering angle of the steering wheel is adjusted to be consistent with the angle between the velocity direction of the current reference point and the coordinate system.

[0027] Optionally, the unmanned forklift comprises an upper fork arm and a lower fork arm;

[0028] When the unmanned forklift is detected to have arrived at the target location, controlling the fork arm to load and unload the cargo according to the loading and unloading instruction includes:

[0029] Detecting operation identification information contained in the loading and unloading instruction;

[0030] If the operation identification information is a loading instruction, detecting the current loading state;

[0031] If the current loading state is an empty state, the upper fork arm is called to complete the loading according to the first preset loading operation;

[0032] If the current loading state is the single-drag state, the lower fork arm is called to complete the loading according to the second preset loading operation;

[0033] If the current loading state is double-support state, a command error message is returned.

[0034] Optionally, according to the identification information, a corresponding preset operation mode is selected to load and unload the cargo, including:

[0035] If the operation identification information is an unloading operation, detecting the current loading state;

[0036] If the current loading state is empty, the command error message is returned;

[0037] If the current loading state is a single-drag state, the upper fork arm is called to complete the unloading action according to the first preset unloading operation;

[0038] If the current loading state is the double-support state, the lower fork arm is called to complete the unloading action according to the second preset unloading operation.

[0039] In addition, to achieve the above-mentioned purpose, the present invention also proposes an unmanned forklift control device, the unmanned forklift control device comprising:

[0040] An instruction acquisition module, used to obtain cargo loading and unloading instructions;

[0041] A steering wheel steering module is used to control the steering angle of the steering wheel according to the cargo loading and unloading instructions, so that the unmanned forklift can drive to the target position along the target driving trajectory;

[0042] The fork arm control module is used to control the fork arm to load and unload cargo according to the cargo loading and unloading instruction when detecting that the unmanned forklift arrives at the target position.

[0043] In addition, to achieve the above-mentioned purpose, the present invention also proposes an unmanned forklift control device, which includes: a memory, a processor, and an unmanned forklift control program stored in the memory and executable on the processor, and the unmanned forklift control program is configured to implement the steps of the unmanned forklift control method described above.

[0044] In addition, to achieve the above-mentioned purpose, the present invention also proposes a storage medium, on which an unmanned forklift control program is stored, and when the unmanned forklift control program is executed by a processor, the steps of the unmanned forklift control method described above are implemented.

[0045] The present invention obtains cargo loading and unloading instructions, controls the steering angle of the steering wheel according to the cargo loading and unloading instructions, and makes the unmanned forklift drive along the target driving trajectory to the target position. When the unmanned forklift is detected to have arrived at the target position, the fork arm is controlled to load and unload cargo according to the cargo loading and unloading instructions. Compared with the prior art, the present invention obtains cargo loading and unloading instructions, determines the direction and angle that each steering wheel needs to deflect according to the cargo loading and unloading instructions, and controls and adjusts the deflection angle of each steering wheel of the unmanned forklift, thereby enabling the unmanned forklift to adjust its own posture within a relatively small range and go to the target position along the path indicated by the instructions to complete the loading and unloading of cargo. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a structural schematic diagram of an unmanned forklift control device in a hardware operating environment involved in an embodiment of the present invention;

[0047] Figure 2 It is a flow chart of the first embodiment of the unmanned forklift control method of the present invention;

[0048] Figure 3 It is a flow chart of the second embodiment of the unmanned forklift control method of the present invention;

[0049] Figure 4 The figure is a schematic diagram of the system composition and data flow of an embodiment of the unmanned forklift control of the present invention.

[0050] Figure 5 A schematic diagram of chassis control of an embodiment of an unmanned forklift control method of the present invention;

[0051] Figure 6 A schematic diagram of a third embodiment of the unmanned forklift control method of the present invention;

[0052] Figure 7 A schematic diagram of a first preset loading operation of an embodiment of an unmanned forklift control method of the present invention;

[0053] Figure 8 A schematic diagram of a second preset loading operation of an embodiment of an unmanned forklift control method of the present invention;

[0054] Fig. 9 A schematic diagram of a first preset unloading operation of an embodiment of an unmanned forklift control method of the present invention;

[0055] Fig.10 A schematic diagram of a second preset unloading operation of an embodiment of an unmanned forklift control method of the present invention;

[0056] Fig.11 A picture of a cargo-carrying vehicle according to an embodiment of the control method of an unmanned forklift of the present invention;

[0057] Fig.12This is a structural block diagram of the first embodiment of the unmanned forklift control device of the present invention.

[0058] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0059] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0060] Reference Figure 1 , Figure 1 The figure is a schematic diagram of the structure of an unmanned forklift control device in the hardware operating environment involved in the embodiment of the present invention.

[0061] like Figure 1 As shown, the unmanned forklift control device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display), an input unit such as a keyboard (Keyboard), and the optional user interface 1003 may also include a standard wired interface and a wireless interface. The network interface 1004 may optionally include a standard wired interface and a wireless interface (such as a wireless fidelity (WIreless-FIdelity, WI-FI) interface). The memory 1005 may be a high-speed random access memory (Random Access Memory, RAM) memory, or a stable non-volatile memory (Non-Volatile Memory, NVM), such as a disk memory. The memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0062] Those skilled in the art will understand that Figure 1 The structure shown in the figure does not constitute a limitation on the unmanned forklift control device, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0063] like Figure 1 As shown, the memory 1005 as a storage medium may include an operating system, a network communication module, a user interface module, and an unmanned forklift control program.

[0064] exist Figure 1In the unmanned forklift control device shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the unmanned forklift control device of the present invention can be set in the unmanned forklift control device, and the unmanned forklift control device calls the unmanned forklift control program stored in the memory 1005 through the processor 1001, and executes the unmanned forklift control method provided by the embodiment of the present invention.

[0065] The embodiment of the present invention provides an unmanned forklift control method, referring to Figure 2 , Figure 2 The figure is a flow chart of a first embodiment of a control method for an unmanned forklift according to the present invention.

[0066] In this embodiment, the unmanned forklift control method includes the following steps:

[0067] Step S10: Obtain cargo loading and unloading instructions.

[0068] It should be noted that the executor of the method of this embodiment can be an unmanned mobile device, which can include a vehicle-mounted controller, at least one steerable wheel and a loading and unloading device, or a device with the same or similar functions. This embodiment and the following embodiments are described using an unmanned forklift as an example.

[0069] It should be understood that the cargo loading and unloading instructions are issued through an instruction sending device, wherein the instruction sending device may be integrated into an unmanned forklift or in the cloud. When the unmanned forklift obtains the cargo loading and unloading instructions, it will perform corresponding actions according to the content contained in the cargo loading and unloading instructions.

[0070] It can be understood that when the instruction sending device is integrated in an unmanned forklift, the cargo loading and unloading instructions are transmitted to the corresponding execution device through the data bus in the unmanned forklift. When the instruction sending device is in the cloud, the cargo loading and unloading instructions can be transmitted via Bluetooth, local area network, etc.

[0071] Step S20: controlling the steering angle of the steering wheel according to the cargo loading and unloading instruction, so that the unmanned forklift drives along the target driving trajectory to the target position.

[0072] It should be noted that the cargo loading and unloading instructions include the driving trajectory and target position of the unmanned forklift. When the unmanned forklift obtains the cargo loading and unloading instructions, it will adjust the rotation angle of the steering wheel on the unmanned forklift chassis according to the driving trajectory and target position contained in the instructions, so that the unmanned forklift can drive to the target position along the specified path.

[0073] It can be understood that the steering wheel on the chassis of the unmanned forklift is a small wheel with a drive and steering system. When multiple steering wheels are combined together, omnidirectional movement can be achieved.

[0074] In the specific implementation, the steering wheels of the unmanned forklift will adjust the deflection angles of each steering wheel according to the cargo loading and unloading instructions. Through the mutual cooperation between the steering wheels, the unmanned forklift can achieve operations such as translation or rotation, and then drive the steering wheels to make the unmanned forklift drive to the target position.

[0075] Step S30: When it is detected that the unmanned forklift arrives at the target location, the fork arm is controlled to load and unload the cargo according to the cargo loading and unloading instruction.

[0076] It should be noted that the unmanned forklift is equipped with a positioning device, which can accurately locate its current location. The unmanned forklift obtains its own position in real time and matches it with the target position to realize the detection of the position of the unmanned forklift. When its own position matches the target position successfully, it will execute the loading and unloading actions of the goods according to the cargo loading and unloading instructions.

[0077] This embodiment analyzes the acquired cargo loading and unloading instructions to obtain the target position of the unmanned forklift and the driving trajectory to the target position. The on-board controller obtains the deflection angle of each steering wheel at the chassis of the unmanned forklift according to the driving trajectory, and adjusts it according to the current position to achieve the translation or rotation operation of the unmanned forklift. With the help of the driving of the steering wheel, the unmanned forklift can reach the target position along the driving trajectory from the command receiving position. When reaching the target position, in order to maintain the movement coordination with the loading and unloading action, it is also necessary to adjust its own position at the target position, so as to achieve the loading and unloading action of the cargo. Therefore, the method provided in this embodiment can achieve the ability to complete translation in any direction or rotation around any point in a relatively small space.

[0078] refer to Figure 3 , Figure 3 The figure is a flow chart of a second embodiment of a control method for an unmanned forklift according to the present invention.

[0079] Based on the first embodiment described above, the unmanned forklift control method of this embodiment includes, in step S20:

[0080] Step S201: obtaining a target travel track of the unmanned forklift according to navigation information included in the cargo loading and unloading instruction.

[0081] Reference Figure 4 , Figure 4 The figure is a schematic diagram of the system composition and data flow of an unmanned forklift. It can be seen from the figure that the unmanned forklift system can include a navigation system, a dispatching system, a control system and an actuator, etc.

[0082] It should be noted that the navigation information is generated by the navigation system, which contains the driving trajectory of the unmanned forklift to the target location. After obtaining the navigation information, the navigation information is added to the cargo loading and unloading instructions.

[0083] Step S202: Acquire the current location of the unmanned forklift.

[0084] Step S203: determining the steering angle of the steering wheel according to the target driving trajectory and the current position, so that the unmanned forklift drives along the target driving trajectory to the target position.

[0085] It should be noted that when the current location and driving trajectory of the unmanned forklift are obtained, the next movement state of the unmanned forklift can be determined, and then the appropriate steering angle of the steering wheel can be adjusted to make the unmanned forklift go to the target location according to the driving trajectory.

[0086] In the specific implementation, the specific position of the current driving trajectory is determined according to the current position and driving path of the unmanned forklift, and the state that the unmanned forklift should maintain in the next action trend is obtained, and the obtained state is transmitted to the motion controller according to the scheduling system, so that the motion controller controls the travel drive and steering drive of the steering wheel, and then controls the travel motor to provide travel power to the steering wheel, and the steering motor adjusts the steering angle of the steering wheel to the target steering angle, so that the unmanned forklift can go to the target position according to the driving trajectory.

[0087] Furthermore, in order to better adjust the steering angle of the steering wheel, step S203 also includes:

[0088] Obtaining a reference point of the unmanned forklift, projecting the reference point onto the target driving trajectory, and obtaining a speed direction of the reference point;

[0089] Obtaining the tangent slope of the reference point at the current curve position according to the velocity direction;

[0090] Obtaining the curvature of the curve at the current position according to the tangent slope of the reference point at the current curve position;

[0091] The steering angle of the steering wheel is obtained according to the curvature of the current position curve.

[0092] It should be noted that the reference point of the unmanned forklift refers to the position of the center point of the unmanned forklift. The reference point is projected onto the driving trajectory to describe the moving trajectory of the unmanned forklift for the convenience of calculation.

[0093] It can be understood that when the unmanned forklift is moving, the unmanned forklift is equivalent to a reference point, and the speed direction of the reference point refers to the speed direction of the unmanned forklift.

[0094] It should be understood that any form of motion can be decomposed and converted into curved motion around a point. If an object moves in a straight line, it can also be regarded as a curved motion, except that the center of rotation of the curved motion is infinitely far away.

[0095] Reference Figure 5 , Figure 5 1 is a schematic diagram of chassis control principle of an embodiment of the present invention, wherein 1 is the main steering wheel, 2 and 3 are auxiliary steering wheel 1 and auxiliary steering wheel 2 respectively, A, B, C are the center points of the three steering wheels respectively, w is the reference point of the unmanned forklift, v is the speed direction of the reference point, v1, v2, v3 are the speed directions of the three steering wheels respectively, curve L is the driving trajectory of the unmanned forklift, O is the instantaneous equivalent rotation center of the unmanned forklift, r, r1, r2, r3 are the rotation radius of the reference point and the three steering wheels respectively.

[0096] In a specific implementation, the tangent of the unmanned forklift on the curve L can be determined according to the speed v of the reference point w, and the tangent is consistent with the speed v of the reference point. After the direction of the tangent is obtained, the slope k of the tangent can be determined according to the direction of the tangent. According to the position of the reference point w and the slope k of the tangent, the curvature c corresponding to the reference point w can be calculated, and then the steering angle of the steering wheel can be obtained.

[0097] Furthermore, in order to more accurately determine the steering angle of the steering wheel, the method further includes the following steps:

[0098] Establishing a vehicle coordinate system with the reference point as the coordinate origin, and acquiring corresponding coordinates of the steering wheel according to the relative position of the steering wheel and the reference point;

[0099] detecting the curvature of the current position curve;

[0100] When the curvature of the current position curve is not equal to a preset value, obtaining the rotation radius of the reference point and the rotation center coordinates of the reference point according to the curvature;

[0101] Obtaining the slope of the steering wheel rotation trajectory according to the rotation radius, the rotation center coordinates, the corresponding coordinates of the steering wheel and the tangent slope of the reference point at the current curve position;

[0102] The steering angle is calculated according to the slope of the steering wheel rotation trajectory.

[0103] It should be noted that the preset value of the curvature is used to distinguish the motion state of the unmanned forklift at this time. The preset value can be 0 or other values. This embodiment will be described with the preset value being 0.

[0104] It can be understood that when the curvature is not equal to 0, it means that the unmanned forklift is performing curved motion and the motion state is rotation. At this time, the three steering wheels need to be deflected by corresponding angles to obtain three different motion directions. Under the action of the steering wheels in these three different motion directions, the unmanned forklift can achieve rotation in the target direction.

[0105] In the specific implementation, in order to better obtain the deflection angle of the steering wheel, the vehicle body coordinate system can be established with the reference point w as the coordinate origin. Correspondingly, m and n are used to represent the positions of the three steering wheels relative to the reference point w in the vehicle body coordinate system. The coordinates of the three steering wheels in the vehicle body coordinate system are:

[0106] A(0,m)

[0107] B(-n,-m)

[0108] C(n,-m)

[0109] The rotation radius of the reference point w is:

[0110]

[0111] The coordinates of the rotation center obtained according to the length of r and the slope k are:

[0112] O(x0,y0)

[0113] in,

[0114]

[0115]

[0116] Therefore, the tangent slopes k1, k2, k3 of the tangent lines corresponding to the curvilinear motion with radii r1, r2, r3 are:

[0117]

[0118]

[0119]

[0120] Thus, the steering angles θ1, θ2, and θ3 of the three steering wheels can be obtained as follows:

[0121]

[0122]

[0123]

[0124] Therefore, according to the above method, the theoretical steering angle of the steering wheel at any position on the curve can be calculated, and by adjusting the steering wheel according to the theoretical steering angle, the unmanned forklift can be moved along the curve to the target position.

[0125] Furthermore, in order to more directly distinguish the motion states of rotation and translation, the method further includes the following steps:

[0126] When the curvature of the current position curve is equal to a preset value, obtaining an angle between the velocity direction of the current reference point and the coordinate system;

[0127] The steering angle of the steering wheel is adjusted to be consistent with the angle between the velocity direction of the current reference point and the coordinate system.

[0128] In the specific implementation, when the curvature c corresponding to the reference point w is 0, it indicates that the unmanned forklift is performing a translational motion at this time. When adjusting the steering angle of the steering wheel, the direction of the steering wheel can be adjusted to be consistent with the speed direction v of the reference point w, thereby realizing the translational movement of the unmanned forklift.

[0129] This embodiment starts with the driving trajectory of the unmanned forklift, divides the trajectory to be driven into several small segments, regards each small segment as doing circular motion, and calculates the corresponding equivalent rotation center and equivalent rotation radius, and determines the slope corresponding to the reference point at this moment according to the speed direction of the reference point, thereby determining the curvature of the curve, and further determining the tangent slope of each steering wheel at this point, thereby obtaining the steering angle of each steering wheel, so that the steering wheel can achieve the steering of the target angle within a very small range, and thus the unmanned forklift can be moved and turned in a very small space.

[0130] refer to Figure 6 , Figure 6 The figure is a flow chart of a third embodiment of a method for controlling an unmanned forklift according to the present invention.

[0131] Based on the above embodiments, the unmanned forklift control method of this embodiment includes, in step S30:

[0132] Step S301: Detecting the operation identification information contained in the loading and unloading instruction;

[0133] Step S302: if the operation identification information is a loading instruction, detecting the current loading state;

[0134] Step S303: If the current loading state is an empty state, the upper fork arm is called to complete the loading according to the first preset loading operation;

[0135] Step S304: if the current loading state is the single-drag state, the lower fork arm is called to complete the loading according to the second preset loading operation;

[0136] Step S305: If the current loading state is the double-support state, a command error message is returned.

[0137] It should be noted that the fork arm of the unmanned forklift includes an upper fork arm and a lower fork arm. The control logic of the upper fork arm and the lower fork arm is different, which can realize the loading and unloading of goods at different positions, and can also carry two pallets of goods at the same time.

[0138] It can be understood that the operation identification information refers to the specific actions that the unmanned forklift is required to perform, including loading and unloading operations.

[0139] It should be understood that when controlling the fork arm, the order of "first in, last out" is adopted. When picking up goods, the upper fork arm is used to take the goods to the top of the vehicle body. At this time, if another picking up task is received, the lower fork arm is used to lift the goods, and then the goods on the lower fork arm are placed, and then the goods on the upper fork arm are placed.

[0140] It should be understood that referring to Figure 7 , Figure 7 This is a schematic diagram of the first preset loading operation. The first preset loading operation is called when the loading state is an empty state. At this time, the upper fork arm is called. Specifically, the upper fork arm is first raised to a certain height and then extended forward. When the upper fork arm is lowered to the height for picking up the goods, the vehicle drives forward. When the goods are picked up, the upper fork arm is lifted and retracted, and the goods are placed on top of the unmanned forklift and the vehicle drives away.

[0141] It is important to understand that referring to Figure 8 , Figure 8 This is a schematic diagram of the second preset loading operation. The second preset loading operation is called when the loading state is a single-tow state. At this time, the lower fork arm is called. Specifically, the lower fork arm is extended, the vehicle drives in to pick up the goods, and the lower fork arm rises to lift the goods and drive away.

[0142] In the specific implementation, when the unmanned forklift drives to the target position, the corresponding action is determined according to the operation identification information in the cargo loading instruction. When the operation identification information is identified as a loading instruction, the scheduling system will allocate the motion controller and the action controller according to the currently completed steps, so that the unmanned forklift completes the forward or backward operation, and the lifting driver controls the pump motor to realize the extension and lifting of the fork arm. For example, when the unmanned forklift carries a pallet of goods on the top, it receives an instruction to pick up the goods again. At this time, it is necessary to dispatch the motion controller to realize driving from the current position to the target position. When the target position is reached, the scheduling system issues a scheduling instruction to control the action controller and the motion controller to cooperate to complete the action of picking up the goods. First, the action controller is called to let the lifting driver control the pump motor to work, so that the lower fork arm extends forward. At this time, the motion controller controls the travel driver to stimulate the travel motor, so that the unmanned forklift moves forward and picks up the goods. When the goods are picked up, the action controller controls the pump motor to lift the lower fork arm, and the motion controller controls the unmanned forklift to leave and complete the cargo loading. If the instruction to load the goods is received again, because the current state is detected as a double-support state, the loading operation is refused and an error message is returned.

[0143] Furthermore, in order to ensure the integrity of cargo loading and unloading, the following steps are also included:

[0144] If the operation identification information is an unloading operation, detecting the current loading state;

[0145] If the current loading state is empty, the command error message is returned;

[0146] If the current loading state is a single-drag state, the upper fork arm is called to complete the unloading action according to the first preset unloading operation;

[0147] If the current loading state is the double-support state, the lower fork arm is called to complete the unloading action according to the second preset unloading operation.

[0148] It should be noted that, refer to Fig. 9 , Fig. 9 This is a schematic diagram of the first preset unloading operation. The first preset unloading operation is called when the loading state is a single-drag state. At this time, the upper fork arm is called. Specifically, the upper fork arm is first raised to a certain height and then extended forward. When the upper fork arm is lowered to the height required for placing the goods, the goods are put down, the unmanned forklift is driven away, and the upper fork arm is controlled to be lifted, retracted and lowered to the initial state.

[0149] It is important to understand that referring to Fig.10 , Fig.10This is a schematic diagram of the second preset unloading operation. The second preset unloading operation is called when the loading state is a double-drag state. At this time, the lower fork arm is called. Specifically, the vehicle drives into the target position, lowers the lower fork arm, puts down the cargo, and retracts the lower fork arm to its initial state.

[0150] Reference Fig.11 , Fig.11 This is a real picture of the goods, which shows the positional relationship between the unmanned forklift's double-supported goods and the fork arms.

[0151] In the specific implementation, when the unmanned forklift receives an unloading instruction, it needs to determine the current loading status. When the loading status at this time is a double-support status, the lower fork arm is first dispatched to execute the second preset write operation to complete the unloading of the goods. After the unloading is completed, when the unloading instruction is received again, the current loading status is detected again. At this time, the loading status is a single-drag status. When it reaches the target position, the upper fork arm is called to execute the first preset unloading operation to complete the unloading of the goods. When the unmanned forklift is in an empty state at this time and receives an unloading instruction, it directly returns an error message and refuses to execute the unloading operation.

[0152] This embodiment realizes different operations of loading or unloading goods under different loading states by separately controlling the upper fork arm and the lower fork arm of the unmanned forklift, and also realizes that the unmanned forklift can carry two pallets of goods at the same time, thereby improving the efficiency of cargo handling during the cargo handling process.

[0153] In addition, an embodiment of the present invention further provides a storage medium, on which an unmanned forklift control program is stored. When the unmanned forklift control program is executed by a processor, the steps of the unmanned forklift control method described above are implemented.

[0154] Reference Fig.12 , Fig.12 This is a structural block diagram of the first embodiment of the unmanned forklift control device of the present invention.

[0155] like Fig.12 As shown, the unmanned forklift control device proposed in the embodiment of the present invention includes:

[0156] The instruction acquisition module 10 is used to acquire cargo loading and unloading instructions.

[0157] The steering wheel steering module 20 is used to control the steering angle of the steering wheel according to the cargo loading and unloading instructions, so that the unmanned forklift can travel to the target position along the target driving trajectory.

[0158] The fork arm control module 30 is used to control the fork arm to load and unload cargo according to the cargo loading and unloading instruction when detecting that the unmanned forklift arrives at the target position.

[0159] This embodiment analyzes the acquired cargo loading and unloading instructions to obtain the target position of the unmanned forklift and the driving trajectory to the target position. The on-board controller obtains the deflection angle of each steering wheel at the chassis of the unmanned forklift according to the driving trajectory, and adjusts it according to the current position to achieve the translation or rotation operation of the unmanned forklift. With the help of the driving of the steering wheel, the unmanned forklift can reach the target position along the driving trajectory from the command receiving position. When reaching the target position, in order to maintain the movement coordination with the loading and unloading action, it is also necessary to adjust its own position at the target position, so as to achieve the loading and unloading action of the cargo. Therefore, the method provided in this embodiment can achieve the ability to complete translation in any direction or rotation around any point in a relatively small space.

[0160] In one embodiment, the steering wheel steering module 20 is further used to obtain the target driving trajectory of the unmanned forklift according to the navigation information contained in the cargo loading and unloading instructions; obtain the current location of the unmanned forklift; determine the steering angle of the steering wheel according to the target driving trajectory and the current location, so that the unmanned forklift travels along the target driving trajectory to the target location.

[0161] In one embodiment, the steering wheel steering module 20 is further used to obtain a reference point of the unmanned forklift, project the reference point onto the target driving trajectory, and obtain the speed direction of the reference point; obtain the tangent slope of the reference point at the current curve position according to the speed direction; obtain the curvature of the current position curve according to the tangent slope of the reference point at the current curve position; and obtain the steering angle of the steering wheel according to the curvature of the current position curve.

[0162] In one embodiment, the steering wheel steering module 20 is further used to establish a vehicle coordinate system with the reference point as the coordinate origin, obtain the corresponding coordinates of the steering wheel according to the relative position of the steering wheel and the reference point; detect the curvature of the current position curve; when the curvature of the current position curve is not equal to a preset value, obtain the rotation radius of the reference point and the rotation center coordinates of the reference point according to the curvature; obtain the slope of the steering wheel rotation trajectory according to the rotation radius, the rotation center coordinates, the corresponding coordinates of the steering wheel and the tangent slope of the reference point at the current curve position; and calculate the steering angle according to the slope of the steering wheel rotation trajectory.

[0163] In one embodiment, the steering wheel steering module 20 is also used to obtain the angle between the speed direction of the current reference point and the coordinate system when the curvature of the current position curve is equal to a preset value; and adjust the steering angle of the steering wheel to be consistent with the angle between the speed direction of the current reference point and the coordinate system.

[0164] In one embodiment, the fork arm control module 30 is also used to detect the operation identification information contained in the loading and unloading instructions; if the operation identification information is a loading instruction, the current loading state is detected; if the current loading state is an empty state, the upper fork arm is called to complete the loading according to the first preset loading operation; if the current loading state is a single-drag state, the lower fork arm is called to complete the loading according to the second preset loading operation; if the current loading state is a double-support state, an instruction error message is returned.

[0165] In one embodiment, the fork arm control module 30 is also used to detect the current loading state if the operation identification information is an unloading operation; if the current loading state is an empty state, return an instruction error message; if the current loading state is a single-drag state, call the upper fork arm to complete the unloading action according to the first preset unloading operation; if the current loading state is a double-support state, call the lower fork arm to complete the unloading action according to the second preset unloading operation.

[0166] It should be understood that the above is only an example and does not constitute any limitation on the technical solution of the present invention. In specific applications, technicians in this field can make settings as needed, and the present invention does not limit this.

[0167] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of the present invention. In practical applications, technicians in this field can select part or all of them according to actual needs to achieve the purpose of the present embodiment, and no limitation is made here.

[0168] In addition, it should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0169] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0170] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as a read-only memory (ROM) / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0171] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for controlling an unmanned forklift, characterized in that: The unmanned forklift control method comprises: Obtain cargo loading and unloading instructions; Controlling the steering angle of the steering wheel according to the cargo loading and unloading instructions so that the unmanned forklift drives along the target driving trajectory to the target location; When it is detected that the unmanned forklift arrives at the target location, the fork arm is controlled to load and unload the cargo according to the cargo loading and unloading instruction; The method of controlling the steering angle of the steering wheel according to the cargo loading and unloading instruction so that the unmanned forklift drives along the target driving trajectory to the target position includes: Obtaining a target driving trajectory of the unmanned forklift according to navigation information contained in the cargo loading and unloading instruction; Obtaining the current location of the unmanned forklift; Determining a steering angle of a steering wheel according to the target driving trajectory and the current position, so that the unmanned forklift drives along the target driving trajectory to the target position; Determining the steering angle of the steering wheel according to the target driving trajectory and the current position of the unmanned forklift includes: Obtaining a reference point of the unmanned forklift, projecting the reference point onto the target driving trajectory, and obtaining a speed direction of the reference point; Obtaining the tangent slope of the reference point at the current curve position according to the velocity direction; Obtaining the curvature of the curve at the current position according to the tangent slope of the reference point at the current curve position; The steering angle of the steering wheel is obtained according to the curvature of the current position curve.

2. The method according to claim 1, characterized in that The step of obtaining the steering angle of the steering wheel according to the curvature of the current position curve comprises: Establishing a vehicle coordinate system with the reference point as the coordinate origin, and acquiring corresponding coordinates of the steering wheel according to the relative position of the steering wheel and the reference point; detecting the curvature of the current position curve; When the curvature of the current position curve is not equal to the preset value, the rotation radius of the reference point and the rotation center coordinates of the reference point are obtained according to the curvature. Obtaining the slope of the steering wheel rotation trajectory according to the rotation radius, the rotation center coordinates, the corresponding coordinates of the steering wheel and the tangent slope of the reference point at the current curve position; The steering angle is calculated according to the slope of the steering wheel rotation trajectory.

3. The method according to claim 2, characterized in that After detecting the curvature of the current position curve, the method further includes: When the curvature of the current position curve is equal to a preset value, obtaining an angle between the velocity direction of the current reference point and the coordinate system; The steering angle of the steering wheel is adjusted to be consistent with the angle between the velocity direction of the current reference point and the coordinate system.

4. The method according to claim 1, characterized in that The unmanned forklift includes an upper fork arm and a lower fork arm; When the unmanned forklift is detected to have arrived at the target location, controlling the fork arm to load and unload the cargo according to the loading and unloading instruction includes: Detecting operation identification information contained in the loading and unloading instruction; If the operation identification information is a loading instruction, detecting the current loading state; If the current loading state is an empty state, the upper fork arm is called to complete the loading according to the first preset loading operation; If the current loading state is the single-drag state, the lower fork arm is called to complete the loading according to the second preset loading operation; If the current loading state is double-support state, a command error message is returned.

5. The method according to claim 4, characterized in that The selecting a corresponding preset operation mode to load and unload goods according to the identification information includes: If the operation identification information is an unloading operation, detecting the current loading state; If the current loading state is empty, the command error message is returned; If the current loading state is a single-drag state, the upper fork arm is called to complete the unloading action according to the first preset unloading operation; If the current loading state is the double-support state, the lower fork arm is called to complete the unloading action according to the second preset unloading operation.

6. An unmanned forklift control device, characterized in that: The unmanned forklift control device comprises: An instruction acquisition module, used to obtain cargo loading and unloading instructions; A steering wheel steering module is used to control the steering angle of the steering wheel according to the cargo loading and unloading instructions, so that the unmanned forklift can drive along the target driving trajectory to the target position; A fork arm control module, used to control the fork arm to load and unload cargo according to the cargo loading and unloading instruction when detecting that the unmanned forklift arrives at the target position; The method of controlling the steering angle of the steering wheel according to the cargo loading and unloading instruction so that the unmanned forklift drives along the target driving trajectory to the target position includes: Obtaining a target driving trajectory of the unmanned forklift according to navigation information contained in the cargo loading and unloading instruction; Obtaining the current location of the unmanned forklift; Determining a steering angle of a steering wheel according to the target driving trajectory and the current position, so that the unmanned forklift drives along the target driving trajectory to the target position; Determining the steering angle of the steering wheel according to the target driving trajectory and the current position of the unmanned forklift includes: Obtaining a reference point of the unmanned forklift, projecting the reference point onto the target driving trajectory, and obtaining a speed direction of the reference point; Obtaining the tangent slope of the reference point at the current curve position according to the velocity direction; Obtaining the curvature of the curve at the current position according to the tangent slope of the reference point at the current curve position; The steering angle of the steering wheel is obtained according to the curvature of the current position curve.

7. An unmanned forklift control device, characterized in that: The device comprises: a memory, a processor, and an unmanned forklift control program stored in the memory and executable on the processor, wherein the unmanned forklift control program is configured to implement the steps of the unmanned forklift control method according to any one of claims 1 to 5.

8. A storage medium, characterized in that: The storage medium stores an unmanned forklift control program, and when the unmanned forklift control program is executed by the processor, the steps of the unmanned forklift control method according to any one of claims 1 to 5 are implemented.

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