A steering control system and steering method for omnidirectional forklifts that enables continuous switching.

Abstract

This invention provides a steering control system and steering method for omnidirectional forklifts that enables continuous switching. The system includes a steering wheel mechanism, a steering wheel, an integrated handle, a main controller, and a drive unit. This invention controls the forklift's steering through a combination of the steering wheel and integrated handle. Combined with the freely rotating steering wheel mechanism, it allows for very intuitive control of the forklift's driving mode. Adjusting the integrated handle switches steering modes without stopping the forklift, significantly reducing the driver's operational difficulty and improving safety, driving flexibility, and transfer efficiency. Furthermore, the steering wheel speed is individually controlled by an accelerator, allowing for separate control of each steering wheel speed in each mode, ensuring consistent steering speed across all modes and enhancing driving comfort and safety.

Description

Technical Field

[0001] This invention relates to the field of forklift control technology, specifically to a steering control system and steering method that enables continuous switching of omnidirectional forklifts. Background Technology

[0002] Forklifts, or industrial handling vehicles, refer to various wheeled handling vehicles used for loading, unloading, stacking, and short-distance transportation of palletized goods. Due to their ease of use and simple operation, they are widely used in various transportation fields. Currently, when traditional forklifts are used to move goods, if the forklift is not aligned with the placement of the goods, it is necessary to reverse the forklift a certain distance, adjust the direction, and then drive the forklift in to place the goods. This method does not allow for lateral or diagonal movement, resulting in problems such as inflexible steering and limited turning range for forklifts. To solve the problem of inflexible steering of traditional forklifts, omnidirectional forklifts were developed. Omnidirectional forklifts can achieve multi-directional operation, including sideways and diagonal movement.

[0003] Existing omnidirectional forklifts mainly have four driving modes: straight driving, side driving, diagonal driving, and stationary turning. Switching between these modes requires stopping because the instantaneous steering center of gravity changes differently, resulting in varying angle and speed relationships for each steering wheel. Furthermore, the current control method, when driving in reverse (i.e., leftward while straight driving or rightward while side driving), involves steering wheel control opposite to forward direction, easily causing confusion for the driver regarding the driving direction and vehicle posture. This requires a high level of driver skill and results in poor driving feel and safety.

[0004] Therefore, there is a need to improve the current steering method of omnidirectional forklifts. The purpose of this invention is to design a steering control system that can facilitate operation and achieve continuous switching of omnidirectional forklifts without stopping. Summary of the Invention

[0005] The purpose of this invention is to provide a steering control system and steering method that enables continuous switching of omnidirectional forklifts, in order to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A steering control system capable of continuous switching of omnidirectional forklifts, comprising:

[0008] A steering wheel mechanism, wherein the steering wheel mechanism can be independently controlled to rotate and at least three sets are provided, and the steering wheel mechanism is provided with a steering wheel and an accelerator for driving the steering wheel to rotate;

[0009] The steering wheel has an encoder inside, which is electrically connected to the main controller to collect the rotation signal of the steering wheel and send it to the main controller.

[0010] An integrated handle is electrically connected to the main controller and is used to provide a switch signal to the main controller to control the vehicle's driving mode, including straight driving mode, side driving mode, stationary turning mode and diagonal driving mode.

[0011] The main controller is electrically connected to the drive device. The main controller collects signals from the integrated handle and encoder to control the drive device.

[0012] A drive device is electrically connected to a steering wheel mechanism, and a single device drives a single steering wheel mechanism, thereby controlling the steering of each steering wheel mechanism.

[0013] In one embodiment, the steering wheel mechanism further includes a drive chain and a steering motor, the steering motor applying steering torque to the rotating wheel via the drive chain, and the drive device employing a steering motor controller.

[0014] In one embodiment, the integrated handle includes four buttons: front, rear, left, right, and center. When the front and rear buttons are activated, the vehicle is controlled to drive straight or turn in place. When the left and right buttons are activated, the vehicle is controlled to drive sideways or turn in place. When the center button is activated, the vehicle is controlled to drive diagonally.

[0015] In one embodiment, the integrated handle adopts a four-way reset lever with up, down, left, and right directions. When the lever is pushed forward or backward, the vehicle is controlled to drive straight or turn in place. When the lever is pushed to the left or right, the vehicle is controlled to drive sideways or turn in place. When the lever is in the neutral position, the vehicle is controlled to drive diagonally.

[0016] In one embodiment, the steering wheel mechanism further includes an angle sensor mounted on the rotating wheel and electrically connected to the main controller for measuring the rotation angle of the rotating wheel.

[0017] This invention also provides a steering method for continuous switching of an omnidirectional forklift. This steering method is applicable to the aforementioned steering control system for continuous switching of an omnidirectional forklift. The steering method decomposes the forklift's motion into a translation vector that translates around the forklift's rotation center point and a rotation vector that rotates around the forklift's rotation center point. The method allows for non-stop switching of the entire vehicle's mode via an integrated handle. The steering method's modes include:

[0018] Straight-line mode: The main direction of the translation vector is automatically changed to the X-axis direction parallel to the direction the forklift is facing. The direction is fixed and the magnitude remains unchanged. The rotation vector is first automatically reset to zero, and then the magnitude and direction of the rotation vector are controlled by the steering wheel.

[0019] Side-moving mode: The main direction of the translation vector changes to the Y-axis direction perpendicular to the forklift's direction of travel. The direction is fixed and the magnitude remains unchanged. The rotation vector first automatically returns to zero, and then the magnitude and direction of the rotation vector are controlled by the steering wheel.

[0020] Stationary Turn Mode: Continuously operate the steering wheel to increase the rotation vector, so that the instantaneous center of the turn enters the projection plane of the vehicle body until it is close to the center of rotation, and then automatically enters the stationary turn mode.

[0021] Diagonal mode: The translation vector maintains the original direction and magnitude, while the rotation vector is automatically reset to zero first, and then the direction of the rotation vector is controlled by the steering wheel.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] This invention uses a combination of a steering wheel and an integrated handle to control the forklift's steering. Combined with a freely rotating steering wheel mechanism, it allows for very intuitive control of the forklift's driving mode. The steering mode can be switched by adjusting the integrated handle without stopping the vehicle, greatly reducing the driver's operational difficulty and improving safety, the driving flexibility of the omnidirectional forklift, and the efficiency of transfer. Moreover, the speed of the steering wheels is controlled separately by the accelerator, allowing for individual control of the speed of each steering wheel in each mode, achieving completely consistent steering speed in all modes, and improving driving comfort and safety. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the system structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the installation of the steering wheel mechanism in this invention;

[0026] Figure 3 This is a schematic diagram of vector synthesis for the side-view mode in this invention;

[0027] Figure 4 This is a schematic diagram of vector synthesis for the straight-line mode in this invention;

[0028] Figure 5 This is a schematic diagram of vector synthesis in the oblique mode of this invention where the rotation vector is zero;

[0029] Figure 6 This is a schematic diagram of vector synthesis in the oblique mode of this invention where the rotation vector is not zero.

[0030] In the diagram: 1. Steering wheel mechanism, 2. Steering wheel, 3. Integrated handle, 4. Main controller, 5. Drive device, 6. Steering wheel, 7. Encoder, 8. Drive chain, 9. Steering motor, 10. Angle sensor, 11. Forklift. 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example:

[0033] Please see Figures 1 to 2 The present invention provides a technical solution:

[0034] A steering control system capable of continuous switching of omnidirectional forklifts includes a steering wheel mechanism 1, a steering wheel 2, an integrated handle 3, a main controller 4, and a drive unit 5, wherein:

[0035] The steering wheel mechanism 1 can be independently controlled to rotate, and at least three sets are provided. The steering wheel mechanism is provided with a steering wheel 6 and an accelerator for driving the steering wheel 6 to rotate. The fact that the steering wheel mechanism 1 can be independently controlled to rotate means that the orientation of the steering wheel 6 can be independently controlled. The steering wheel mechanism 1 is located at the bottom of the forklift 11. The travel speed of the steering wheel 6 is controlled by the accelerator alone. The speed of each steering wheel 6 can be controlled separately in each mode to achieve completely consistent steering speed in each mode, thereby improving driving comfort and safety.

[0036] The drive device 5 is electrically connected to the steering wheel mechanism 1, and a single device drives the steering wheel mechanism 1, controlling the steering of each steering wheel mechanism 1 respectively. That is, each steering wheel mechanism 1 is driven by an independent drive device 5.

[0037] Furthermore, the steering wheel mechanism 1 also includes a transmission chain 8 and a steering motor 9. The steering motor 9 applies steering torque to the rotating wheel 6 through the transmission chain 8, thereby causing the steering wheel 6 to rotate. The drive device 5 adopts a steering motor controller, which drives the steering motor 9 to work.

[0038] Optionally, the steering mechanism of the rotating wheel 6 can also be driven by a hydraulic cylinder to change the orientation of the rotating wheel 6, and the corresponding driving device 5 can be a hydraulic cylinder driving device.

[0039] Furthermore, the steering wheel mechanism 1 also includes an angle sensor 10, which is mounted on the rotating wheel 6 and electrically connected to the main controller 4. The angle sensor 10 is used to measure the rotation angle of the rotating wheel 6 for more accurate control.

[0040] The steering wheel 2 is mounted on the forklift 11. An encoder 7 is installed inside the steering wheel 2. When the steering wheel 2 rotates, it drives the encoder 7 to rotate simultaneously. The encoder 7 is electrically connected to the main controller 4 and is used to collect the rotation signal of the steering wheel 2 and send it to the main controller 4. The encoder 7 converts the angular displacement of the steering wheel 2 into an electrical signal and sends it to the main controller 4.

[0041] The integrated handle 3 is electrically connected to the main controller 4 and is used to provide a switch signal to the main controller 4 to control the vehicle's travel mode, including straight travel mode, side travel mode, stationary turn mode and diagonal travel mode. The integrated handle 3 is installed on the forklift 11.

[0042] Furthermore, the integrated handle 3 includes four buttons: front, back, left, right, and center. When the front and back buttons are activated, the forklift 11 is controlled to either straight-line mode or stationary turning mode. When the left and right buttons are activated, the forklift is controlled to either side-moving mode or stationary turning mode. When the center button is activated, the forklift is controlled to either diagonal-moving mode.

[0043] Optionally, the integrated handle 3 adopts a four-way reset control lever with up, down, left and right directions. When the control lever is pushed forward or backward, the forklift 11 is controlled to be in straight-line mode or stationary turning mode. When the control lever is pushed to the left or right, the forklift is controlled to be in side-moving mode or stationary turning mode. When the control lever is in the middle neutral position, the forklift 11 is controlled to be in diagonal-moving mode.

[0044] The main controller 4 is based on the embedded chip STM32. The main controller 4 is electrically connected to the drive device 5. The main controller 4 collects signals from the integrated handle 3 and the encoder 7, and controls the drive device 5. The drive device 5 controls the corresponding steering wheel mechanism 1 to steer. The steering wheel 2 and the integrated handle 3 are used to control the steering of the forklift 11. With the steering wheel mechanism 1 that can rotate freely, the driving mode of the entire forklift 11 can be controlled very intuitively. The steering mode can be switched by adjusting the integrated handle 3 without stopping the vehicle. This greatly reduces the difficulty of operation for the driver, improves safety and the driving flexibility and transfer efficiency of the omnidirectional forklift.

[0045] Please see Figures 3 to 6 The present invention also provides a steering method for realizing continuous switching of omnidirectional forklifts. The steering method is applicable to the above-mentioned steering control system for realizing continuous switching of omnidirectional forklifts. In this embodiment, forklift 11 has four steering wheel mechanisms 1 as an example. In the figure, a1 refers to the translation vector, a2 represents the rotation vector, a1n refers to the translation vector a1 of the steering wheel 6 of the nth steering wheel mechanism 1, a2n refers to the rotation vector a2 of the steering wheel 6 of the nth steering wheel mechanism 1, An refers to the composite vector of the nth steering wheel 6, O is the rotation center, and C refers to the instantaneous center of turn.

[0046] The steering method decomposes the motion of the forklift 11 into a translation vector that translates around the rotation center point of the forklift 11 and a rotation vector that rotates around the rotation center point of the forklift 11. The integrated handle 3 allows for non-stop switching of the vehicle's mode. The steering method's modes include:

[0047] Straight-line mode: The main direction of the translation vector is automatically changed to the X-axis direction parallel to the direction of the forklift 11. The direction is fixed and the magnitude remains unchanged. The rotation vector is first automatically reset to zero, and then the magnitude and direction of the rotation vector are controlled by the steering wheel 2.

[0048] The direction of the composite vector of each steering wheel 6 is the direction of the steering wheel 6. The magnitude of the composite vector can be regarded as the speed ratio of the steering wheel 6. As the magnitude of the rotation vector changes, the instantaneous center of rotation moves along the Y-axis, which is the straight-line mode.

[0049] Side-moving mode: The main direction of the translation vector is changed to the Y-axis direction perpendicular to the direction of the forklift 11. The direction is fixed and the magnitude remains unchanged. The rotation vector is first automatically reset to zero, and then the magnitude and direction of the rotation vector are controlled by the steering wheel 2.

[0050] The direction of the composite vector of each steering wheel 6 is the direction of the steering wheel 6, and the magnitude of the composite vector can be regarded as the speed ratio of the steering wheel 6. As the magnitude of the rotation vector changes, the instantaneous center of rotation moves along the axis, which is the side-driving mode.

[0051] Stationary turn mode: Continuously operate the steering wheel 2 to continuously increase the rotation vector, so that the instantaneous center of rotation enters the vehicle body projection plane until it is close to the center of rotation, and automatically enters the stationary turn mode.

[0052] Diagonal mode: The translation vector maintains the original direction and magnitude, while the rotation vector is automatically reset to zero first, and then the direction of the translation vector is controlled by steering wheel 2.

[0053] In this embodiment, the motion of the forklift 11 is divided into translation vector and rotation vector. The steering method of the forklift 11 in each mode is unified by the vector synthesis method, realizing the non-stop continuous switching of driving mode of the omnidirectional forklift 11, which improves the driving flexibility and transfer efficiency of the omnidirectional forklift 11.

[0054] The translation vector can be seen as the translational movement of the forklift 11 towards the predetermined cargo position, and the rotation vector can be seen as the adjustment of the vehicle body posture to facilitate the forklift 11's forks facing the cargo pallet. The process of the forklift 11 picking up and placing cargo is the synthesis of these two movements.

[0055] The operation method of this embodiment is to intuitively control the travel direction of the omnidirectional forklift 11 through the middle gear of the integrated handle 3. Pushing forward moves the forklift forward, and pushing left moves it left, which greatly reduces the difficulty of operation for the driver and improves safety.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A steering method for enabling continuous switching of omnidirectional forklifts, characterized in that, The steering method is based on a steering control system, which includes: A steering wheel mechanism, wherein the steering wheel mechanism can be independently controlled to rotate and at least three sets are provided, and the steering wheel mechanism is provided with a steering wheel and an accelerator for driving the steering wheel mechanism to rotate; The steering wheel has an encoder inside, which is electrically connected to the main controller to collect the rotation signal of the steering wheel and send it to the main controller. An integrated handle is electrically connected to the main controller and is used to provide a switch signal to the main controller to control the vehicle's driving mode, including straight driving mode, side driving mode, stationary turning mode and diagonal driving mode. The main controller is electrically connected to the drive device. The main controller collects signals from the integrated handle and encoder to control the drive device. A drive device is electrically connected to a steering wheel mechanism, and a single device drives a single steering wheel mechanism, thereby controlling the steering of each steering wheel mechanism. The steering wheel mechanism also includes a transmission chain and a steering motor. The steering motor applies steering torque to the rotating wheel through the transmission chain, and the drive device uses a steering motor controller. The steering wheel mechanism also includes an angle sensor, which is mounted on the rotating wheel and electrically connected to the main controller for measuring the rotation angle of the rotating wheel. The steering method decomposes the forklift's motion into a translation vector that translates around the forklift's rotation center point and a rotation vector that rotates around the forklift's rotation center point. It allows for non-stop switching of the vehicle's mode via an integrated handle. The steering method's modes include: Straight-line mode: The main direction of the translation vector is automatically changed to the X-axis direction parallel to the direction the forklift is facing. The direction is fixed and the magnitude remains unchanged. The rotation vector is first automatically reset to zero, and then the magnitude and direction of the rotation vector are controlled by the steering wheel. Side-moving mode: The main direction of the translation vector changes to the Y-axis direction perpendicular to the direction the forklift is facing. The direction is fixed and the magnitude remains unchanged. The rotation vector first automatically returns to zero, and then the magnitude and direction of the rotation vector are controlled by the steering wheel. Stationary Turn Mode: Continuously operate the steering wheel to bring the instantaneous center of the turn into the vehicle's projection plane until it approaches the center of rotation, at which point it will automatically enter the stationary turn mode. Diagonal mode: The translation vector maintains the original direction and magnitude, while the rotation vector is automatically reset to zero first, and then the direction of the translation vector is controlled by the steering wheel.

2. The steering method for continuous switching of an omnidirectional forklift according to claim 1, characterized in that: The integrated handle includes four buttons: front, back, left, right, and center. When the front and back buttons are activated, the vehicle is controlled to drive straight or turn in place. When the left and right buttons are activated, the vehicle is controlled to drive sideways or turn in place. When the center button is activated, the vehicle is controlled to drive diagonally.

3. The steering method for continuous switching of an omnidirectional forklift according to claim 1, characterized in that: The integrated handle uses a four-way reset lever with up, down, left, and right directions. When the lever is pushed forward or backward, the vehicle is controlled to drive straight or turn in place. When the lever is pushed to the left or right, the vehicle is controlled to drive sideways or turn in place. When the lever is in the neutral position, the vehicle is controlled to drive diagonally.

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