Remote walking control system and method for forklift

Abstract

The invention belongs to the technical field of diesel fork lift truck control, and provides a forklift remote walking control system and method.The forklift remote walking control system comprises a remote operation device used for outputting a walking control signal; a signal receiving device; the vehicle execution unit comprises a reversing device, a speed measuring device, an electronic hydraulic braking device and a power device; the vehicle control unit is configured to control the reversing device to set the traveling direction of the forklift based on the polarity of the traveling control signal; when the amplitude of the walking control signal is smaller than the maximum value, a braking force mapping instruction is generated to control an electronic hydraulic braking device to provide braking force related to the amplitude, and a basic power instruction is generated to control a power device; and when the amplitude value reaches the maximum value, a speed closed-loop instruction is generated so that the walking speed of the forklift can approach the preset safety speed by adjusting the driving force output of the power device according to the feedback of the speed measuring device. The technical problems that in the prior art, remote control over the forklift is rough, and accurate micro-motion cannot be achieved can be solved.

Description

Technical Field

[0001] This application relates to the field of internal combustion forklift control technology, and in particular to a forklift remote walking control system and method. Background Technology

[0002] Forklifts, as core equipment for material handling, are widely used in warehousing, logistics hubs, ports, and large manufacturing workshops. However, in many special working conditions, the traditional human-driven mode faces significant challenges: in toxic, hazardous, high-temperature, explosive, or highly radioactive environments, the health and safety of drivers are directly threatened; in enclosed or extreme environments such as cold storage and clean rooms, prolonged operation places stringent demands on human tolerance; and in scenarios such as loading and unloading inside containers, in high-level aisles on racks, or on loading platforms, drivers have serious blind spots, leading not only to low operational efficiency but also to a higher risk of collisions. Furthermore, in operations requiring extremely high precision, such as handling precision instruments and assembling molds, relying solely on driver experience is insufficient to achieve millimeter-level stable control. Therefore, developing reliable remote control technology for forklifts to achieve "human-vehicle separation" and "human-machine collaboration" has significant engineering value and practical implications for ensuring personnel safety, improving operational accuracy, and expanding application boundaries.

[0003] Currently, most common simple remote control solutions in the industry rely on wireless communication modules to transmit relay switching signals, enabling only discrete inching control of basic movements such as forward, backward, left turn, right turn, lifting, and lowering. These solutions cannot continuously and linearly adjust travel speed and lack precise support for low-speed micro-motion conditions, resulting in stiff remote control actions and positioning difficulties, making it unsuitable for high-precision operations such as precise pallet insertion and obstacle avoidance in confined spaces. On the other hand, high-performance remote control systems directly transplanted from the construction machinery field, while possessing proportional control and multi-channel coordination capabilities, are typically designed based on entirely new electro-hydraulic architectures, resulting in high costs. Furthermore, they are difficult to deeply integrate with existing systems commonly used in forklifts, such as hydraulic braking and hydraulic steering, requiring large-scale modifications to the entire vehicle. This high integration complexity, long development cycle, and uncontrollable costs hinder their widespread application in the existing forklift market and cost-sensitive scenarios.

[0004] While various remote-controlled forklift control schemes exist in the current technology, none can effectively achieve micro-motion control and rely on precise adjustments to the throttle / handle displacement by the operator. For example, patent CN102817721B discloses a device for real-time speed adjustment of a forklift's power system, including a displacement detection device, a clutch status detection device, a speed adjustment device, and a PLC control unit. The displacement detection device and clutch status detection device are connected to the PLC control unit, which is also connected to the speed adjustment device. The displacement detection device and clutch status detection device transmit signals to the PLC control unit, which processes the signals and then transmits them to the speed adjustment device. The patent also discloses a method for real-time speed adjustment of the forklift's power system. This method can not only increase the engine speed according to operating conditions but also automatically adjust the engine speed when the handle is operated. However, in micro-motion conditions, in order to ensure that the engine does not stall and responds, the engine is usually maintained at a higher speed than idle speed. At this time, the vehicle may only be crawling over very small resistance, resulting in poor engine fuel economy. Moreover, in remote or complex conditions, it requires a high level of skill from the operator and depends on the driver's precise operation.

[0005] Therefore, how to design a cost-effective, precise, and highly integrated remote travel control system based on the existing forklift system architecture has become a technical problem that needs to be solved in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a remote forklift movement control system and method, which can solve the technical problems of coarse control, inability to achieve precise micro-motion, and low integration with the original vehicle system in existing remote forklift control schemes; and has the advantages of precise micro-motion control, safety and reliability, and ease of implementation.

[0007] To achieve the above and related objectives, the present invention employs the following technical means:

[0008] The first aspect of this invention provides a remote forklift travel control system, comprising: a remote operating device having an operating handle for outputting travel control signals corresponding to the displacement magnitude and direction of the operating handle; a signal receiving device wirelessly connected to the remote operating device for receiving the travel control signals; a vehicle execution unit including a reversing device, a speed measuring device, an electro-hydraulic braking device, and a power device; and a vehicle controller communicatively connected to the signal receiving device and each device in the vehicle execution unit, wherein the vehicle controller is configured to: control the reversing device to set the forklift travel direction based on the polarity of the travel control signal; when the amplitude of the travel control signal is less than the maximum value, generate a braking force mapping command to control the electro-hydraulic braking device to provide braking force associated with the amplitude, and generate a basic power command to control the power device; when the amplitude reaches the maximum value, generate a speed closed-loop command to adjust the driving force output of the power device according to the feedback from the speed measuring device so that the forklift travel speed approaches a preset safe speed.

[0009] Furthermore, the operating handle is equipped with a horizontal joystick, and the walking control signal is generated by the displacement of the horizontal joystick.

[0010] Furthermore, when the amplitude is less than the maximum value, the braking force mapping command is to make the braking force provided by the electro-hydraulic braking device and the absolute value of the travel control signal have a preset inverse proportional function relationship.

[0011] Furthermore, when the amplitude reaches its maximum value, the speed closed-loop command is controlled by proportional-integral regulation.

[0012] Furthermore, the reversing device is a reversing solenoid valve, and the speed measuring device is a speed sensor.

[0013] Furthermore, the signal receiving device is connected to the vehicle controller via the vehicle's CAN bus.

[0014] Furthermore, the vehicle controller is connected to the power unit via hardwire.

[0015] A second aspect of the present invention provides a method for remotely controlling the movement of a forklift, comprising the following steps:

[0016] Responding to the travel control signal output by the forklift remote control handle;

[0017] The reversing device is controlled according to the polarity of the travel control signal to set the travel direction of the forklift;

[0018] Obtain the current amplitude of the travel control signal and the real-time travel speed of the forklift;

[0019] When the current amplitude is less than the maximum value, a braking force mapping command is sent to the electro-hydraulic braking device according to the current amplitude to control the electro-hydraulic braking device to provide the corresponding braking force, and at the same time control the power device to provide the basic driving force.

[0020] When the current amplitude reaches its maximum value, the driving force output of the power unit is adjusted through closed-loop control based on the difference between the real-time walking speed and the preset safe speed, so that the real-time walking speed approaches the preset safe speed.

[0021] Furthermore, the maximum value is the amplitude when the operating handle reaches its maximum stroke.

[0022] Furthermore, when the current amplitude is less than the maximum value, the braking force provided by the control electro-hydraulic braking device decreases as the absolute value of the amplitude increases, and works in conjunction with the basic driving force provided by the power unit to perform linear micro-motion control on the forklift.

[0023] The beneficial technical effects of this invention are as follows:

[0024] This invention fully utilizes the existing electronic control system of forklifts, such as the vehicle controller and electro-hydraulic braking device. By innovating the control logic of the electronic control system, it multiplexes the traditional single analog travel control signal into a comprehensive command source for direction, micro-motion control, and speed limit. This enables precise travel control comparable to local driving in remote mode, thereby achieving accurate control and high integration. It solves the technical problems of coarse control, inability to achieve precise micro-motion, and low integration with the original vehicle system in existing forklift remote control solutions.

[0025] This invention employs a strategy of constant basic driving force combined with variable braking force in the reverse adjustment under low-speed micro-motion conditions, i.e. when the amplitude is less than the maximum value. This makes the forklift travel speed and the displacement of the lever linear and smooth. The braking force is used as the active adjustment quantity, rather than only when the vehicle is stopped. This can achieve movement that is superior to the traditional method of controlling movement solely by the throttle, and is suitable for remote precision operation scenarios.

[0026] When the vehicle is intended to travel at full speed, i.e. when the amplitude reaches its maximum value, this invention uses speed closed-loop control to keep the maximum travel speed within a preset safe speed value. This can fundamentally avoid the danger of vehicle speeding that may occur when the command is continuously at its maximum during remote operation, thereby achieving active speed limiting and improving safety.

[0027] This invention is mainly based on software logic innovation, requiring minimal hardware modification. It only adds a remote control handle and a signal receiving device, making it easy to install and modify on existing forklift platforms. It has the advantages of low cost, ease of implementation, and strong scalability.

[0028] The micro-motion control logic of this invention conforms to the driver's intuition, which makes it easier to remotely operate forklifts for precise positioning and narrow passage operations, reducing the difficulty of remote operation and improving the user experience.

[0029] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0030] The accompanying drawings, incorporated in and forming part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without inventive effort. In the drawings:

[0031] Figure 1 This is a schematic block diagram of the control system of this application;

[0032] Figure 2 This is a schematic diagram showing the mapping relationship between the walking control signal and the braking control in this application;

[0033] Figure 3 This is a flowchart of the control method of this application;

[0034] Figure 4 This is the control logic flowchart of the vehicle controller in this application.

[0035] Figure Labels

[0036] 100: Walking system; 101: Reversing solenoid valve; 102: Speed ​​sensor; 200: Electro-hydraulic braking system; 201: Brake controller; 202: Brake actuator; 300: Power system; 400: Vehicle controller; 500: Remote operating device; 501: Operating handle; 502: Signal receiver. Detailed Implementation

[0037] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should be understood that certain features of the invention (described in the context of separate embodiments for clarity) may also be provided in a single embodiment. Conversely, multiple features of the invention (described in the context of a single embodiment for brevity) may also be provided separately or in any suitable combination or, where appropriate, in any other described embodiment of the invention. Certain features described in the context of various embodiments will not be considered essential features of those embodiments unless the embodiment is inoperable without those elements. The invention is further illustrated below by specific examples; however, it should be noted that the specific process conditions and results described in the embodiments of the invention are merely illustrative and should not be construed as limiting the scope of protection of the invention. All equivalent changes or modifications made in accordance with the spirit and essence of the invention should be covered within the scope of protection of the invention.

[0038] like Figure 1 As shown, this application provides a forklift remote travel control system, including: a remote operating device 500, which has an operating handle 501 for outputting travel control signals corresponding to the displacement magnitude and direction of the operating handle 501; a signal receiving device, which is wirelessly connected to the remote operating device 500 for receiving travel control signals; a vehicle execution unit, including a reversing device, a speed measuring device, an electro-hydraulic braking device, and a power device; and a vehicle controller 400, which is communicatively connected to the signal receiving device and each device in the vehicle execution unit. The vehicle controller 400 is configured to: control the reversing device to set the forklift travel direction based on the polarity of the travel control signal; when the amplitude of the travel control signal is less than the maximum value, generate a braking force mapping command to control the electro-hydraulic braking device to provide braking force associated with the amplitude, and generate a basic power command to control the power device; when the amplitude reaches the maximum value, generate a speed closed-loop command to adjust the driving force output of the power device according to the feedback from the speed measuring device, so that the forklift travel speed approaches a preset safe speed.

[0039] Furthermore, the operating handle 501 is equipped with a horizontal joystick, and the travel control signal is generated by the displacement of the horizontal joystick. The operating handle 501 in this application is handheld and has a built-in wireless transmission module. The X-axis output of the horizontal joystick, for example, an analog voltage of -3.3V to +3.3V, represents the backward / forward movement and its desired speed. The signal receiving device in this application is a signal receiver 502 with a built-in wireless receiving module and a CAN interface. The signal receiver 502 is installed on the forklift. The travel control signal sent by the operating handle 501 is wirelessly transmitted (e.g., 2.4G / 5.8G) to the signal receiver 502, where it is converted into a CAN message, for example, message ID 0x200. Data byte 0 contains a scalarized speed expectation value of -100 to +100, and is then sent to the vehicle's CAN network. Furthermore, the mechanical displacement of the rocker arm in this application is converted into a continuous analog travel control signal through internal components such as potentiometers. The direction of displacement represents the polarity, corresponding to the forward and backward commands of the forklift; the magnitude of displacement represents the amplitude, determining the absolute value of the signal.

[0040] Furthermore, the vehicle execution unit of this application includes a travel system 100, which in turn includes a reversing device for switching forward / backward, a speed measuring device for detecting the actual travel speed of the forklift, a gear pump, a gearbox, a drive axle, and other components. Preferably, the reversing device is a reversing solenoid valve 101, and the speed measuring device is a speed sensor 102, which can be installed on the drive axle of the forklift.

[0041] Furthermore, the electro-hydraulic braking device (also referred to as the electro-hydraulic braking system 200) of this application is a configurable system for existing forklifts, comprising a brake controller 201 and a brake actuator 202 controlled by the controller. The brake actuator 202 typically includes components such as a hydraulic valve assembly and brake calipers. The brake controller 201 communicates with the upper-level controller via a CAN bus and receives braking force mapping commands.

[0042] Furthermore, the power unit (also referred to as the power system 300) of this application includes an engine / generator and an electronic control unit (ECU / MCU), the throttle opening of which is controlled by analog voltage or PWM signal.

[0043] Furthermore, the hardware of the vehicle controller 400 in this application can adopt a high-performance MCU commonly used in vehicles. Its I / O interface is hard-wired to the commutation solenoid valve 101 and the speed sensor 102; its CAN bus interface is connected to the brake controller 201 and the signal receiving device respectively; and it is also hard-wired to the throttle control terminal of the power system 300 through an analog output or PWM output.

[0044] Furthermore, such as Figure 2As shown, when the amplitude is less than the maximum value, the braking force mapping command is to make the braking force provided by the electro-hydraulic braking device and the absolute value of the travel control signal have a preset inverse proportional function relationship. The maximum value in this application is the amplitude when the operating handle 501 reaches its maximum stroke. Furthermore, Figure 2 The horizontal axis represents the opening of the horizontal lever, i.e., the absolute value of the travel control signal |V_cmd| as referred to in this application, ranging from the neutral position 0 to the maximum travel ±100%, representing the amplitude of the operator pushing the horizontal lever; the vertical axis represents the braking force, i.e., the braking force required by the electro-hydraulic braking device (also referred to as the electro-hydraulic braking system 200) as referred to in this application. When the horizontal lever is in the neutral position, i.e., |V_cmd|=0, the braking force is at its maximum F=MAX, corresponding to the forklift coming to a complete stop; as |V_cmd| increases, the required braking force decreases linearly. When |V_cmd|=V_max, the braking force drops to zero, F=0, at which point the system switches to another mode. When the vehicle controller 400 receives the |V_cmd| signal in real time and determines that |V_cmd|<V_max, i.e., it is in a micro-motion condition, it immediately calls... Figure 2 The inverse proportional function relationship shown calculates the target braking force F_brake based on the current |V_cmd| value. Then, the vehicle controller 400 sends a braking force mapping command containing F_brake to the brake controller 201 via the CAN bus. The brake controller 201 drives the brake actuator 202 to accurately output the calculated braking force. Simultaneously, the vehicle controller 400 outputs a small, constant base throttle Th_base to the power unit (also called the power system 300). Furthermore, under low-speed micro-motion conditions, this application employs a strategy of constant base driving force combined with variable braking force in reverse adjustment, resulting in a linear and smooth correspondence between the forklift's travel speed and the displacement of the rocker arm. Using braking force as the active adjustment quantity, it achieves intuitive and high-precision micro-motion with light push for slow travel and heavy push for fast travel.

[0045] Furthermore, when the amplitude reaches or exceeds the maximum value, the speed closed-loop command control method is proportional-integral (PI) control. When |V_cmd| = V_max is detected, the system immediately and automatically switches from micro-motion mode to speed closed-loop control mode. At this time, the input to the vehicle controller 400 is the difference between the preset safe speed V_safe and the actual forklift travel speed V_actual, i.e. This application then employs a PI controller (proportional-integral controller) to dynamically calculate the throttle opening based on the error e. The proportional term generates an adjustment proportional to the current error e; the larger the error, the stronger the adjustment, resulting in a rapid response and quick reduction of the error. The integral term generates an adjustment proportional to the integral of the error e over time, used to eliminate steady-state error and achieve zero steady-state speed tracking. The PI controller adds the calculation results of the proportional and integral terms, outputting a dynamically changing throttle opening command, Throttle. This application directly outputs the throttle opening command to the power system 300, enabling the forklift to maintain stable V_safe driving even under the maximum command, preventing the risk of speeding during remote control. At this time, the braking force command is set to zero.

[0046] like Figure 3 and Figure 4 As shown, this application also provides a method for remotely controlling the movement of a forklift, comprising the following steps:

[0047] S1. Responds to the travel control signal output by the forklift remote control handle.

[0048] S2. Control the reversing device to set the forklift's travel direction according to the polarity of the travel control signal.

[0049] Furthermore, this application analyzes the travel control signal. If the |V_cmd| of the signal is not zero, the control reversing device switches to forward or backward state according to the signal polarity, i.e., positive or negative, thereby determining the forklift's travel direction.

[0050] S3. Obtain the current amplitude of the travel control signal and the real-time travel speed of the forklift.

[0051] S4. When the current amplitude is less than the maximum value, a braking force mapping command is sent to the electro-hydraulic braking device according to the current amplitude to control the electro-hydraulic braking device to provide the corresponding braking force, and at the same time control the power device to provide the basic driving force.

[0052] Furthermore, if the current amplitude |V_cmd| is less than the maximum value and is in the low to medium range, then it corresponds to the micro-motion condition. Based on the preset amplitude-braking force mapping relationship, the target braking force F_brake is calculated. F_brake decreases as |V_cmd| increases, and a braking force mapping command is sent to the brake controller to control the braking execution structure to provide the corresponding braking force while maintaining a small base throttle.

[0053] S5. When the current amplitude reaches its maximum value, the driving force output of the power unit is adjusted through closed-loop control based on the difference between the real-time walking speed and the preset safe speed, so that the real-time walking speed approaches the preset safe speed.

[0054] Furthermore, if the current amplitude |V_cmd| reaches the maximum value V_max, then the corresponding full-speed command is issued. The difference between the preset safe speed V_safe and the real-time travel speed V_actual is calculated, and the required throttle opening Throttle is calculated through the PI adjustment algorithm to make V_actual approach V_safe. The throttle control signal is then output to the power system, at which point the braking force is fully released.

[0055] The present invention will be described in detail below through specific examples and embodiments. It should also be understood that the following embodiments are only for specific illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0056] Example 1

[0057] This embodiment provides a forklift remote travel control system, including a travel system 100, an electro-hydraulic braking system 200, a power system 300, a vehicle controller 400, and a remote operation device 500.

[0058] When the system in this embodiment is running, the vehicle controller 400 receives the expected speed value, V_cmd, output from the joystick of the operating handle 501 from the CAN bus, and executes the following control logic:

[0059] 1) Signal analysis and direction control: Determine V_cmd. If V_cmd=0, control the reversing solenoid valve 101 to return to the neutral position and the forklift stops running; if V_cmd>0, control the reversing solenoid valve 101 to be energized to the forward position; if V_cmd<0, control the reversing solenoid valve 101 to be energized to the reverse position.

[0060] 2) Micro-motion control: When the absolute value of V_cmd, |V_cmd|, is less than the maximum value, i.e., the preset micro-motion threshold V_max, the forklift is considered to be in micro-motion mode, and the control is applied according to the following... Figure 2 The mapping relationship shown indicates that the desired braking force F_brake_cmd is inversely proportional to |V_cmd| in a linear relationship. K1 is a coefficient.

[0061] Simultaneously, the control power system 300 outputs a small, fixed base throttle signal Th_base. The vehicle controller 400 sends a command containing F_brake_cmd to the brake controller 201 via the CAN bus. The brake controller 201 then uses closed-loop control to achieve the desired braking force through the brake actuator 202. In this way, the forklift can move slowly and smoothly under low signal, forced braking, and low throttle conditions, with the moving speed proportional to the amplitude of the push of the rocker arm.

[0062] 3) Full Speed ​​and Speed ​​Limit Control: When the absolute value of V_cmd, |V_cmd|, reaches its maximum value, V_max, corresponding to the push-to-the-end joystick, the vehicle controller 400 switches to the speed closed-loop control mode. In this mode, the target travel speed is the preset safe speed, V_safe, for example, 10km / h. The vehicle controller 400 reads the forklift travel speed, V_actual, fed back by the speed sensor 102, calculates the speed error e = V_safe - V_actual, and then dynamically calculates the throttle opening based on the error through a proportional-integral regulator. This throttle signal is then output to the power system, ensuring that the forklift can maintain a stable travel speed at the preset safe speed even under maximum command, preventing loss of control. At this time, the braking force command is set to zero.

[0063] In this embodiment, the electro-hydraulic braking system 200 is used for micro-motion control of the vehicle and is seamlessly connected with the throttle control. Through the intelligent decision-making of the vehicle controller 400, the precise "slowing down - acceleration - speed limiting" full-process control in remote state is achieved through a single joystick. The entire control system has a smooth response and is safe and reliable.

[0064] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A forklift remote movement control system, characterized in that, include: The remote operating device (500) has an operating handle (501) for outputting a walking control signal corresponding to the displacement magnitude and direction of the operating handle (501); A signal receiving device, which is wirelessly connected to the remote operating device (500), is used to receive the walking control signal; The vehicle actuator includes a reversing device, a speed measuring device, an electro-hydraulic braking device, and a power unit; A vehicle controller (400) is communicatively connected to the signal receiving device and each device in the vehicle execution unit, wherein the vehicle controller (400) is configured as follows: Based on the polarity of the travel control signal, the reversing device is controlled to set the forklift's travel direction; When the amplitude of the walking control signal is less than the maximum value, a braking force mapping command is generated to control the electro-hydraulic braking device to provide braking force associated with the amplitude, and a basic power command is generated to control the power device. When the amplitude reaches the maximum value, a speed closed-loop command is generated to adjust the driving force output of the power unit to make the forklift travel speed approach the preset safe speed based on the feedback from the speed measuring device.

2. The control system according to claim 1, characterized in that, The operating handle (501) is equipped with a horizontal rocker arm, and the walking control signal is generated by the displacement of the horizontal rocker arm.

3. The control system according to claim 1 or 2, characterized in that, When the amplitude is less than the maximum value, the braking force mapping command is to make the braking force provided by the electro-hydraulic braking device have a preset inverse proportional function relationship with the absolute value of the walking control signal.

4. The control system according to claim 1, characterized in that, When the amplitude reaches the maximum value, the speed closed-loop command is controlled by proportional-integral regulation.

5. The control system according to claim 1, characterized in that, The reversing device is a reversing solenoid valve (101), and the speed measuring device is a speed sensor (102).

6. The control system according to claim 1, characterized in that, The signal receiving device is connected to the vehicle controller (400) via the vehicle CAN bus.

7. The control system according to claim 1, characterized in that, The vehicle controller (400) is connected to the power unit via a hard wire.

8. A method for remote movement control of a forklift, characterized in that, Includes the following steps: Responding to the travel control signal output by the forklift remote control handle; The reversing device is controlled according to the polarity of the travel control signal to set the travel direction of the forklift; Obtain the current amplitude of the travel control signal and the real-time travel speed of the forklift; When the current amplitude is less than the maximum value, a braking force mapping command is sent to the electro-hydraulic braking device according to the current amplitude to control the electro-hydraulic braking device to provide the corresponding braking force, and at the same time control the power device to provide the basic driving force. When the current amplitude reaches the maximum value, the driving force output of the power device is adjusted through closed-loop control based on the difference between the real-time walking speed and the preset safe speed, so that the real-time walking speed approaches the preset safe speed.

9. The control method according to claim 8, characterized in that, The maximum value is the amplitude when the operating handle reaches its maximum stroke.

10. The control method according to claim 8, characterized in that, When the current amplitude is less than the maximum value, the braking force provided by the electro-hydraulic braking device is reduced as the absolute value of the amplitude increases, and in conjunction with the basic driving force provided by the power device, linear micro-motion control is performed on the forklift.

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