Steering control method and system for electric forklift

Abstract

The embodiment of the invention provides an electric forklift steering control method and system, and belongs to the technical field of forklift control. The control method comprises the following steps: judging whether a brake pedal or an accelerator pedal is treaded or not and a driver does not operate a steering wheel to rotate or not; when it is detected that a driver operates the steering wheel to rotate, the steering angle sensor detects that the steering wheel starts to rotate from a static state and detects whether the rotating speed is larger than a first rotating disc preset threshold value or not; under the condition that the rotating speed of the steering wheel is larger than a first rotating disc preset threshold value, a pump electric controller controls the rotating speed of a pump motor to be directly increased to a first motor preset threshold value and lasts for a first preset time; after a first preset time, the pump electric controller controls the rotating speed of the pump motor to be reduced to a second motor preset threshold value; judging whether the rotating speed of the steering wheel continuously increases or not; according to the control method, steering of the forklift can be triggered by triggering the steering wheel.

Description

Technical Field

[0001] The present invention relates to the technical field of forklift control, and particularly to a steering control method and system for an electric forklift. Background Art

[0002] In the existing steering control systems of electric forklifts, the steering motor and the pump motor generally share a pump motor. To prevent emergencies during the operation of the forklift and enable emergency steering, when the brake pedal or the accelerator is depressed, the steering system is always in a working state, and its pump motor (steering motor) operates at a constant speed. Throughout the operation of the forklift, the pump motor continuously operates at a relatively high speed, but this results in energy waste.

[0003] Currently, to trigger the steering function by starting the steering wheel, it is achieved by depressing the brake pedal or the accelerator. The steering system operates at a fixed speed, and the driver is not aware of the number of turns of the steering wheel, the angle of rotation of the steering wheel, the position of the tires, and the direction of rotation during steering. Therefore, the current steering system is not intelligent and has low steering efficiency. Thus, a forklift control method that can trigger the forklift to turn by triggering the steering wheel is needed. Summary of the Invention

[0004] An object of an embodiment of the present invention is to provide a steering control method and system for an electric forklift, and the control method can trigger the steering of the forklift by triggering the steering wheel.

[0005] To achieve the above object, an embodiment of the present invention provides an electric forklift steering control method, and the control method includes:

[0006] Determine whether the brake pedal or the accelerator pedal is depressed and the driver does not operate the steering wheel.

[0007] When it is detected that the driver operates the steering wheel, the angle sensor detects the steering wheel starting to rotate from a stationary state and detects whether the rotation speed is greater than a first preset threshold of the turntable.

[0008] When the rotation speed of the steering wheel is greater than the first preset threshold of the turntable, the pump electronic control controls the rotation speed of the pump motor to directly increase to a first preset threshold of the motor and lasts for a first preset time.

[0009] After the first preset time, the pump electronic control controls the rotation speed of the pump motor to decrease to a second preset threshold of the motor.

[0010] Determine whether the rotation speed of the steering wheel continues to increase.

[0011] When the rotation speed of the steering wheel continues to increase, the pump electronic control controls the rotation speed of the pump motor to increase at the speed of formula (1) to reduce the damping of the steering wheel:

[0012] f(x) = lnx + b, Formula (1)

[0013] Wherein, x represents the rotation speed of the steering wheel, and x is greater than the preset threshold of the first turntable, and b represents a preset constant value.

[0014] Optionally, when the rotation speed of the steering wheel reaches the preset threshold of the second turntable, the pump electronic control controls the rotation speed of the pump motor to be maintained at the preset threshold of the first motor, wherein the preset threshold of the second turntable is greater than the preset threshold of the first turntable.

[0015] Optionally, when the rotation speed of the steering wheel decreases, the pump electronic control controls the rotation speed of the pump motor to decrease linearly, and when the rotation speed of the steering wheel is 0, controls the pump motor to operate at the speed of the second preset threshold of the motor, and stops after maintaining for the second preset time.

[0016] Optionally, when it is detected that the brake pedal or the accelerator pedal is depressed and the driver does not operate the steering wheel, the pump motor is controlled to operate at the speed of the second preset threshold of the motor.

[0017] Optionally, the control method includes:

[0018] During the forklift driving process, judge whether the time when the driver leaves the seat exceeds 3 seconds;

[0019] When the time when the driver leaves the seat does not exceed 3 seconds, the entire forklift does not report a fault, and returns to the step of judging whether the brake pedal or the accelerator pedal is depressed and the driver does not operate the steering wheel;

[0020] When the time when the driver leaves the seat exceeds 3 seconds, the entire forklift reports a fault, and returns to the step of judging whether the brake pedal or the accelerator pedal is depressed and the driver does not operate the steering wheel.

[0021] On the other hand, the present invention also provides an electric forklift steering control system, and the control system includes:

[0022] A battery for supplying power to the control system;

[0023] A display instrument, both ends of which are connected to both ends of the battery to display information in the control system;

[0024] A pump electronic control, connected to the display instrument through a CAN communication line and connected to both ends of the battery, and a resistor is connected between the battery and the pump electronic control;

[0025] A pump motor, connected to the pump electronic control through an encoder;

[0026] An accelerator, electrically connected to the pump;

[0027] A foot brake switch, electrically connected to the pump;

[0028] A seat switch, electrically connected to the pump;

[0029] An accelerator, electrically connected to the pump;

[0030] A DC - DC module, connected to the battery and capable of being electrically connected to the pump through a steering encoder to supply power to the pump's electric control. A resistor is connected between the DC - DC module and the battery.

[0031] Optionally, the control system includes a steering encoder disposed in the steering wheel column. The steering encoder has three - phase outputs of A, B, and C. When the steering encoder rotates one week, the A - phase outputs a pulse signal, and the B / C - phases output K pulse signals with a phase difference.

[0032] Optionally, the speed of the steering wheel rotation is obtained by calculating the duration of the B - phase signal and the number of high - level signals within the duration.

[0033] Optionally, the rotation direction of the steering wheel is obtained by the pump's electric control judging the phase sequence of the levels of the B - phase and C - phase.

[0034] Optionally, the steering angle of the tires of the electric forklift is calculated by the number of levels passed by the B - phase or C - phase to obtain the steering angle of the steering wheel, and then the pump's electric control calculates it through the steering coefficient between the steering wheel and the tires.

[0035] Through the above technical solution, a steering control method and system for an electric forklift provided by the present invention control the rotation of the steering wheel by determining whether the driver steps on the brake pedal or the accelerator pedal and whether the driver operates the steering wheel to rotate. When it is detected that the driver operates the steering wheel to rotate, the angle sensor can detect the rotation of the steering wheel starting from the stationary state and can detect whether the rotation speed of the steering wheel is greater than the first preset threshold of the turntable. When the rotation speed of the steering wheel is greater than the first preset threshold of the turntable, the pump electronic control can control the rotation speed of the pump motor to directly increase to the first preset threshold of the motor and can last for the first preset time. This kind of control can change the steering system of the forklift from static to dynamic. A larger motor rotation speed can pump out more hydraulic oil to overcome the static resistance of the hydraulic system, so that the driver will not feel a great resistance at the initial moment of turning the steering wheel. After the pump electronic control controls the rotation speed of the pump motor to reach the first preset threshold of the motor and after the first preset time, the pump electronic control can control the rotation speed of the pump motor to drop to the second preset threshold of the motor. Because at this time, after overcoming the static hydraulic resistance, the steering function has been triggered. In order to reduce energy consumption, the pump electronic control controls the rotation speed of the pump motor to drop to a lower rotation speed, that is, the second preset threshold of the motor. After the rotation speed of the pump motor is at a lower rotation speed, it can be determined whether the rotation speed of the steering wheel is continuously increasing. When the rotation speed of the steering wheel is continuously increasing, the pump electronic control can control the rotation speed of the pump motor to increase at the speed of formula (1), so as to reduce the damping of the steering wheel. The pump electronic control controls the rotation speed of the pump motor to increase at the speed of formula (1) in order to keep the damping of the steering wheel at a smaller state when the driver quickly turns the steering wheel, making the driver's operation more comfortable. And by increasing the rotation speed of the pump motor at the speed of formula (1), the steering wheel can rotate quickly from the initial state to a certain rotation speed, and when it is about to reach the limit value of the rotation speed, the damping of the steering wheel can start to increase and the increment of the rotation speed of the pump motor can be reduced, so that the driver can better control the steering wheel. This control method can trigger the steering of the forklift by triggering the steering wheel.

[0036] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent specific implementation part. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementation, they are used to explain the embodiments of the present invention, but do not constitute a limitation to the embodiments of the present invention. In the drawings:

[0038] Figure 1 is the first flowchart of a steering control method for an electric forklift according to an embodiment of the present invention;

[0039] Figure 2It is the second flowchart of a steering control method for an electric forklift according to an embodiment of the present invention;

[0040] Figure 3 It is the system connection diagram of a steering control system for an electric forklift according to an embodiment of the present invention;

[0041] Figure 4 It is the schematic diagram of the pulse output of three phases A, B, and C according to an embodiment of the present invention. Specific embodiments

[0042] The following will describe in detail the specific embodiments of the embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining and illustrating the embodiments of the present invention, and are not used to limit the embodiments of the present invention.

[0043] In the embodiments of the present application, some industry-existing solutions such as certain software, components, models, etc. may be mentioned. They should be considered exemplary. The purpose is only to illustrate the feasibility in the implementation of the technical solutions of the present application, but it does not mean that the applicant has already or necessarily used this solution.

[0044] Figure 1 It is the first flowchart of a steering control method for an electric forklift according to an embodiment of the present invention. In the present invention, the process of this control method may include:

[0045] In step S1, it is judged whether the brake pedal or the accelerator pedal is depressed and the driver has no operation of turning the steering wheel.

[0046] In step S2, when it is detected that the driver has an operation of turning the steering wheel, the steering angle sensor detects that the steering wheel starts to rotate from the stationary state and detects whether the rotation speed is greater than the first preset threshold of the turntable.

[0047] In step S3, when the rotation speed of the steering wheel is greater than the first preset threshold of the turntable, the pump electronic control controls the rotation speed of the pump motor to directly increase to the first preset threshold of the motor and lasts for the first preset time.

[0048] In step S4, after the first preset time, the pump electronic control controls the rotation speed of the pump motor to drop to the second preset threshold of the motor.

[0049] In step S5, it is judged whether the rotation speed of the steering wheel continues to increase.

[0050] In step S6, when the rotation speed of the steering wheel continues to increase, the pump electronic control controls the rotation speed of the pump motor to increase at the speed of formula (1) to reduce the damping of the steering wheel:

[0051] f(x) = lnx + b, formula (1)

[0052] Wherein, x represents the rotation speed of the steering wheel, and x is greater than the preset threshold of the first turntable, and b represents a preset constant value.

[0053] In the present invention, it is judged whether the driver steps on the brake pedal or the accelerator pedal, and it is judged whether the driver operates the steering wheel to control the rotation of the steering wheel. In the logic of controlling the steering of the electric forklift, whether the steering wheel rotates is the priority control logic. When it is detected that the driver operates the steering wheel to rotate, the angle sensor can detect that the steering wheel starts to rotate from the stationary state, and can detect whether the rotation speed of the steering wheel is greater than the preset threshold of the first turntable. When the rotation speed of the steering wheel is greater than the preset threshold of the first turntable, the pump electronic control can control the rotation speed of the pump motor to directly increase to the preset threshold of the first motor, and can last for the first preset time. This kind of control can make the steering system of the forklift change from static to dynamic. A larger motor rotation speed can pump out more hydraulic oil to overcome the static resistance of the hydraulic system, so that the driver will not feel a great resistance at the initial moment of turning the steering wheel. If the rotation speed of the steering wheel is not greater than the preset threshold of the first turntable, it can be indicated that the driver has no intention of steering at this time, and the pump electronic control can not control the rotation speed of the pump motor to the preset threshold of the first motor. After the pump electronic control controls the rotation speed of the pump motor to reach the preset threshold of the first motor and after the first preset time, the pump electronic control can control the rotation speed of the pump motor to drop to the preset threshold of the second motor. Because at this time, after overcoming the static hydraulic resistance, the steering function has been triggered. In order to reduce energy consumption, the pump electronic control controls the rotation speed of the pump motor to drop to a lower rotation speed, that is, the preset threshold of the second motor. After the rotation speed of the pump motor is at a lower rotation speed, it can be judged whether the rotation speed of the steering wheel is continuously increasing. When the rotation speed of the steering wheel is continuously increasing, the pump electronic control can control the rotation speed of the pump motor to increase at the speed of formula (1), so as to reduce the damping of the steering wheel. The pump electronic control controls the rotation speed of the pump motor to increase at the speed of formula (1) in order to make the damping of the steering wheel maintain at a smaller state whether the driver turns the steering wheel quickly or slowly, making the driver's operation more comfortable. And by increasing the rotation speed of the pump motor at the speed of formula (1), the steering wheel can rotate quickly from the initial state to a certain rotation speed, and when it is about to reach the limit value of the rotation speed, the damping of the steering wheel can start to increase, reducing the increment of the rotation speed of the pump motor, slowing down the time for the steering wheel to reach the limit speed, and avoiding the steering wheel speed from being too fast, so that the driver can better control the steering wheel. This control method can trigger the steering of the forklift by triggering the steering wheel.

[0054] In an embodiment of the present invention, when the rotation speed of the steering wheel reaches the preset threshold of the second turntable, the pump electronic control can control the rotation speed of the pump motor to be maintained at the speed of the first motor preset threshold. The preset threshold of the second turntable can be greater than the preset threshold of the first turntable, and the preset threshold of the second turntable can be the maximum speed of the turntable.

[0055] In an embodiment of the present invention, as Figure 1 shown, in step S7, when the rotation speed of the steering wheel decreases, the pump electronic control controls the rotation speed of the pump motor to decrease linearly, and when the rotation speed of the steering wheel is 0, controls the pump motor to operate at the speed of the second motor preset threshold and stops after maintaining for the second preset time.

[0056] When the rotation speed of the steering wheel decreases, the pump electronic control can control the rotation speed of the pump motor to decrease linearly. When the rotation speed of the steering wheel is 0, the pump electronic control can control the pump motor to operate at the speed of the second motor preset threshold and can stop after maintaining for the second preset time, aiming to reduce the energy consumption.

[0057] In an embodiment of the present invention, as Figure 1 shown, in step S8, when it is detected that the brake pedal or the accelerator pedal is depressed and the driver does not operate the steering wheel, the pump motor is controlled to operate at the speed of the second motor preset threshold.

[0058] When it is detected that the brake pedal or the accelerator pedal is depressed and the driver does not operate the steering wheel, the pump motor can be controlled to operate at the speed of the second motor preset threshold. The speed of the second motor preset threshold can be the minimum idle speed. This operation can ensure the existence of steering when the vehicle is driving straight, enable quick steering to avoid danger in case of an accident, and keep the steering idle speed at a relatively low level during straight driving, reducing the energy consumption of the whole vehicle to the lowest state, and generally extending the battery usage time by about 7%.

[0059] In an embodiment of the present invention, as Figure 2 shown, the second process of the steering control method can include:

[0060] In step S9, during the forklift driving process, it is judged whether the time when the driver leaves the seat exceeds 3 seconds.

[0061] In step S10, when the time when the driver leaves the seat does not exceed 3 seconds, the forklift vehicle does not report a fault and returns to the step of judging whether the brake pedal or the accelerator pedal is depressed and the driver does not operate the steering wheel.

[0062] In step S11, if the driver has been away from the seat for more than 3 seconds, the entire forklift reports a fault, and it returns to the step of determining whether the brake pedal or the accelerator pedal is depressed and the driver has no operation of turning the steering wheel.

[0063] In the present invention, when the entire vehicle is in motion, the delay time of the seat switch can be 3 seconds to prevent the entire vehicle from reporting a fault due to the driver leaving the seat briefly when driving on a bumpy road. Therefore, it can be determined whether the time the driver is away from the seat exceeds 3 seconds. If the time the driver is away from the seat does not exceed 3 seconds, the entire forklift may not report a fault and return to step S1 to normally control the turning of the steering wheel. If the time the driver is away from the seat exceeds 3 seconds, the entire forklift may report a fault, the forklift can stop, and it can return to step S1 to normally control the turning of the steering wheel.

[0064] On the other hand, the present invention also provides an electric forklift steering control system. As Figure 3 shown, the control system may include: a battery, a display instrument, a pump electronic control, a pump motor, an accelerator, a foot brake switch, a seat switch, an accelerator, and a DC-DC module. The battery can supply power to the control system. The display instrument can display information such as the rotation speed and rotation direction of the steering wheel and the rotation angle of the tire. Both ends of the display instrument can be connected to both ends of the battery. The pump electronic control can be connected to the display instrument through a CAN communication line and can also be connected to both ends of the battery. A resistor can be connected between the battery and the pump electronic control. The pump motor can be connected to the pump electronic control through an encoder to be controlled by the pump electronic control. The accelerator can be connected to the pump electronic control to be controlled by the pump electronic control. The foot brake switch can be connected to the pump electronic control. The seat switch can be connected to the pump electronic control to detect whether the driver is in the seat. The accelerator can be connected to the pump electronic control. The DC-DC module can be connected to the battery and can be connected to the pump electronic control through a steering encoder to supply power to the pump electronic control. A resistor can be connected between the DC-DC module and the battery.

[0065] In an embodiment of the present invention, the control system may include a steering encoder. The above-mentioned corner sensor can be a steering encoder. The steering encoder can be arranged in the steering wheel column. The steering encoder can be provided with three-phase outputs of A, B, and C. When the steering encoder rotates one week, phase A can output a pulse signal, and phases B / C can output K pulse signals with a phase difference. As Figure 4 shown, therefore, by calculating the pulses of the three phases of A, B, and C, the rotation speed and steering of the steering wheel can be obtained. When detecting the number of turns of the steering of the steering wheel, when turning one circle, phase A outputs a low-level signal to the pump electronic control, and remains high-level at other times. Therefore, by the number of low-level signals output by phase A, the number of turns of the steering wheel rotation can be determined.

[0066] In one embodiment of the present invention, when calculating the rotation speed of the steering wheel, it can be obtained by calculating the duration of the B-phase signal and the number of high-level signals within the duration. The pump electronic control calculates the duration of the B-phase signal and the number of high-level signals within the duration (the time axis is related to the speed of the steering wheel), calculates the real-time speed of the steering wheel through the pump electronic control, and the calculation period of the pump electronic control is 50 milliseconds. Then, the calculated value is used to display the speed on the instrument interface through CAN communication.

[0067] In one embodiment of the present invention, by the pump electronic control judging the phase sequence of the appearance of the B and C levels, it can be judged whether it is a left turn or a right turn. Through the situation of the B / C phase sequence, the correctness of the pipelines and oil circuits of the steering system can be judged.

[0068] In one embodiment of the present invention, calculated from the number of levels of the B phase and the C phase, there are a total of K per revolution, and one is equal to degrees. Therefore, the angle of rotation of the steering wheel can be calculated by the number of levels passed by the B phase or the C phase. The pump electronic control then calculates the angle of rotation of the corresponding tire through the steering coefficient of the steering wheel and the tire, and enables the angle of the tire to be displayed on the instrument in real time, thereby improving the driver's judgment of the steering wheel and greatly improving the intelligence of steering.

[0069] Through the above technical solution, a steering control method and system provided by the present invention control the rotation of the steering wheel by determining whether the driver steps on the brake pedal or the accelerator pedal and whether the driver operates the steering wheel. When it is detected that the driver operates the steering wheel, the angle sensor can detect the rotation of the steering wheel starting from the stationary state and can detect whether the rotation speed of the steering wheel is greater than the first preset threshold of the turntable. When the rotation speed of the steering wheel is greater than the first preset threshold of the turntable, the pump electronic control can control the rotation speed of the pump motor to directly increase to the first preset threshold of the motor and can last for the first preset time. This kind of control can change the steering system of the forklift from static to dynamic. A larger motor rotation speed can pump out more hydraulic oil to overcome the static resistance of the hydraulic system, so that the driver will not feel a great resistance at the initial moment of turning the steering wheel. After the pump electronic control controls the rotation speed of the pump motor to reach the first preset threshold of the motor and after the first preset time, the pump electronic control can control the rotation speed of the pump motor to drop to the second preset threshold of the motor. Because at this time, after overcoming the static hydraulic resistance, the steering function has been triggered. In order to reduce energy consumption, the pump electronic control controls the rotation speed of the pump motor to drop to a lower rotation speed, that is, the second preset threshold of the motor. After the rotation speed of the pump motor is at a lower rotation speed, it can be determined whether the rotation speed of the steering wheel is continuously increasing. When the rotation speed of the steering wheel is continuously increasing, the pump electronic control can control the rotation speed of the pump motor to increase at the speed of formula (1), so as to reduce the damping of the steering wheel. The pump electronic control controls the rotation speed of the pump motor to increase at the speed of formula (1) in order to keep the damping of the steering wheel at a smaller state when the driver quickly turns the steering wheel, making the driver's operation more comfortable. And by increasing the rotation speed of the pump motor at the speed of formula (1), the steering wheel can rotate quickly from the initial stage to a certain rotation speed, and when approaching the limit value of the rotation speed, the damping of the steering wheel can start to increase and the increment of the rotation speed of the pump motor can be reduced, so that the driver can better control the steering wheel. This control method can trigger the steering of the forklift by triggering the steering wheel.

[0070] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0071] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, as well as the combination of flows and / or blocks in the flowchart and / or block diagram. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one or more of the flows Figure 1 or more flows and / or blocks Figure 1 or more blocks.

[0072] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in one or more of the flows Figure 1 or more flows and / or blocks Figure 1 or more blocks.

[0073] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more of the flows Figure 1 or more flows and / or blocks Figure 1 or more blocks.

[0074] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and a memory.

[0075] The memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM), and / or non-volatile memory such as read-only memory (ROM) or flash memory (flash RAM). The memory is an example of computer-readable media.

[0076] A computer-readable medium includes both permanent and non-permanent, removable and non-removable media and can implement information storage by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer-readable medium does not include transitory computer-readable media such as modulated data signals and carrier waves.

[0077] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0078] The above are only embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A steering control method for an electric forklift, characterized in that: The control method comprises: Determine whether the brake pedal or accelerator pedal is pressed and the driver does not turn the steering wheel; When it is detected that the driver has turned the steering wheel, the steering angle sensor detects that the steering wheel starts to turn from a stationary state, and detects whether the turning speed is greater than a first preset threshold of the steering wheel; When the rotation speed of the steering wheel is greater than the preset threshold of the first rotary disk, the pump electronic control controls the pump motor speed to directly increase to the first motor preset threshold and lasts for a first preset time; After a first preset time, the pump electronic control controls the pump motor speed to drop to a second motor preset threshold; Determine whether the rotation speed of the steering wheel continues to increase; When the rotation speed of the steering wheel continues to increase, the pump electronic control controls the speed of the pump motor to increase at a speed of formula (1) to reduce the damping of the steering wheel: f(x)=lnx+b, formula (1) Wherein, x represents the rotation speed of the steering wheel, and x is greater than the first turntable preset threshold value, and b represents a preset constant value.

2. The control method according to claim 1, characterized in that: When the rotation speed of the steering wheel reaches the second turntable preset threshold, the pump electronic control controls the rotation speed of the pump motor to maintain at the first motor preset threshold, wherein the second turntable preset threshold is greater than the first turntable preset threshold.

3. The control method according to claim 2, characterized in that: When the rotation speed of the steering wheel decreases, the pump electronic control controls the rotation speed of the pump motor to drop linearly, and when the rotation speed of the steering wheel is 0, controls the pump motor to run at a speed of a second motor preset threshold, and stops after maintaining the speed for a second preset time.

4. The control method according to claim 1, characterized in that: When it is detected that the brake pedal or the accelerator pedal is depressed and the driver does not perform a steering wheel rotation operation, the pump motor is controlled to operate at a speed of a preset threshold value of the second motor.

5. The control method according to claim 4, characterized in that: The control method comprises: During the driving process of the forklift, determine whether the driver has been away from the seat for more than 3 seconds; If the driver leaves the seat for less than 3 seconds, the forklift does not report a fault and returns to the step of determining whether the brake pedal or accelerator pedal is pressed and the driver does not turn the steering wheel; If the driver leaves the seat for more than 3 seconds, the forklift reports a fault and returns to the step of determining whether the brake pedal or the accelerator pedal is pressed and the driver does not turn the steering wheel.

6. An electric forklift steering control system, characterized in that: The control system comprises: A battery to power the control system; A display instrument, two ends of which are connected to two ends of the battery to display information in the control system; A pump electronic control is connected to the display instrument through a CAN communication line and is connected to both ends of the battery, and a resistor is connected between the battery and the pump electronic control; A pump motor, electrically connected to the pump via an encoder; an accelerator, electrically connected to the pump; A foot brake switch, electrically connected to the pump; A seat switch, electrically connected to the pump; an accelerator, electrically connected to the pump; A DC-DC module is connected to the battery and can be connected to the pump electronic control via a steering encoder to supply power to the pump electronic control. A resistor is connected between the DC-DC module and the battery.

7. The control system according to claim 6, characterized in that: The control system includes a steering encoder, which is arranged in the steering wheel column. The steering encoder has three-phase outputs of A, B, and C. When the steering encoder rotates one circle, phase A outputs a pulse signal, and phases B / C output K pulse signals with phase differences.

8. The control system according to claim 7, characterized in that: The speed of the steering wheel rotation is obtained by calculating the duration of the B-phase signal and the number of high levels during the duration.

9. The control system according to claim 7, characterized in that: The rotation direction of the steering wheel is obtained by the pump electronic control judging the phase sequence of the B-phase and C-phase levels.

10. The control system according to claim 7, characterized in that: The steering angle of the tire of the electric forklift is calculated by the number of electrical levels of phase B or phase C, and the angle of steering wheel rotation is then calculated by the pump electronic control through the steering coefficient of the steering wheel and tire.

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