EP4692567A1 - Hydraulic system and hydraulic control method based on multi-execution-state data collection - Google Patents

Hydraulic system and hydraulic control method based on multi-execution-state data collection

Info

Publication number
EP4692567A1
EP4692567A1 EP24921604.5A EP24921604A EP4692567A1 EP 4692567 A1 EP4692567 A1 EP 4692567A1 EP 24921604 A EP24921604 A EP 24921604A EP 4692567 A1 EP4692567 A1 EP 4692567A1
Authority
EP
European Patent Office
Prior art keywords
forklift
hydraulic
hydraulic control
cylinder
hydraulic system
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP24921604.5A
Other languages
German (de)
French (fr)
Other versions
EP4692567A4 (en
Inventor
Jun Zhou
Sheng BI
Meng Wu
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Anhui Heli Co Ltd
Original Assignee
Anhui Heli Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Anhui Heli Co Ltd filed Critical Anhui Heli Co Ltd
Publication of EP4692567A1 publication Critical patent/EP4692567A1/en
Publication of EP4692567A4 publication Critical patent/EP4692567A4/en
Pending legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/06—Control using electricity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/02—Servomotor systems with program control derived from a store or timing device; Control devices therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/0759—Details of operating station, e.g. seats, levers, operator platforms, cabin suspension
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/20—Means for actuating or controlling masts, platforms, or forks
    • B66F9/22—Hydraulic devices or systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/20—Means for actuating or controlling masts, platforms, or forks
    • B66F9/24—Electrical devices or systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/08—Servomotor systems incorporating electrically operated control means
    • F15B21/087—Control strategy, e.g. with block diagram
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B19/00—Testing; Calibrating; Fault detection or monitoring; Simulation or modelling of fluid-pressure systems or apparatus not otherwise provided for
    • F15B19/002—Calibrating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B19/00—Testing; Calibrating; Fault detection or monitoring; Simulation or modelling of fluid-pressure systems or apparatus not otherwise provided for
    • F15B19/007—Simulation or modelling
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/08—Servomotor systems incorporating electrically operated control means
    • F15B21/082—Servomotor systems incorporating electrically operated control means with different modes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/20507—Type of prime mover
    • F15B2211/20515—Electric motor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/275—Control of the prime mover, e.g. hydraulic control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6306—Electronic controllers using input signals representing a pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6306—Electronic controllers using input signals representing a pressure
    • F15B2211/6313—Electronic controllers using input signals representing a pressure the pressure being a load pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6336—Electronic controllers using input signals representing a state of the output member, e.g. position, speed or acceleration
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6346—Electronic controllers using input signals representing a state of input means, e.g. joystick position
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/665—Methods of control using electronic components
    • F15B2211/6651—Control of the prime mover, e.g. control of the output torque or rotational speed
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/665—Methods of control using electronic components
    • F15B2211/6658—Control using different modes, e.g. four-quadrant-operation, working mode and transportation mode
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/88—Control measures for saving energy

Definitions

  • the present invention relates the technical field of forklifts, and specifically to a self-feedback energy control system and a control method for a heavy-duty electric forklift hydraulic system based on multi-actuation-state data collection.
  • Heavy-duty electric forklifts generally refer to electric forklifts loading 6 tons or more. They use batteries as power to drive motors and hydraulic systems to work, achieving walking, loading and unloading functions. Heavy-duty electric forklifts are heavy in themselves, and the weight of the whole machine is even greater after loading, so the power required for work is also large. Due to the limitation that all major systems in the overall layout of the machine will occupy a certain space, the size of the power battery cannot be designed to be very large, resulting in a limited endurance capacity of the battery.
  • VCU Vehicle Control Unit
  • a hydraulic control model of the present invention proposes an optimal control strategy for the hydraulic system by collecting and processing hydraulic performance parameters of different drivers in different actuation states, and autonomously outputs required hydraulic performance under a set expected actuation state. At this time, the driver controls the hydraulic action only by inputting a signal and does not participate in controlling the rotational speed of the motor, entering an autonomous control state, so that the hydraulic action output of the whole vehicle best fits the current driver's working habits.
  • the present invention has got the function of independently collecting the individual operating habits of multiple people on the vehicle.
  • the entire process of each driver's driving control habits is recorded into a data dot matrix.
  • the person's operating habit recommendation mode is automatically switched, and a set point triggering the operating habits is identified to implement active control.
  • An objective of the present invention is to provide a hydraulic system and a control method based on multi-actuation-state data collection. Therefore, the operating habits can be collected to the maximum extent possible, and the working state of each actuator cylinder is fixed to an operation state that can meet the operational efficiency requirements, and can also save energy and adapt to the driver's habits.
  • a hydraulic control method based on multi-actuation-state data collection comprising the following steps:
  • the hydraulic control model comprises the operation frequency, the average values of the performance parameters of the hydraulic system, the control value, and the rotational speed of the pump motor.
  • step S7 once the driver operates the forklift handle, the operation frequency of the forklift in each actuation state is synchronously detected; and when the operation frequency is 20% less than an operation frequency in the hydraulic control model for three consecutive times, the hydraulic control model is deactivated and the driver needs to manually control the hydraulic system of the forklift to work.
  • step S7 after the driver operates the forklift handle, the forklift's load weight is first detected to determine whether the forklift is unloaded or loaded with goods, and then the forklift is autonomously controlled to work according to an output of a corresponding hydraulic control model.
  • the actuator cylinder comprises a lifting cylinder, a tilting cylinder and a side shifting cylinder; and the actuation states comprise raising, lowering, forward tilting, backward tilting, left shifting and right shifting operation states of the forklift.
  • step S2 the performance parameters of the hydraulic system comprise oil pressure, load, running time, running speed and cylinder stroke of the actuator cylinder.
  • the specified value in step S4 means that: a specified value for a lifting speed is ⁇ 30 mm/s, a specified value for a tilting speed is 1.2°/s, and a specified value for a side shifting speed is ⁇ 9 mm/s.
  • a pressure sensor is installed in the actuator cylinder to detect the oil pressure; and the running speed is calculated according to the running time and stroke of the actuator cylinder.
  • Another inventive objective of the present invention is to provide a hydraulic system for implementing the hydraulic control method described above, comprising a forklift handle, a vehicle control unit, a pump motor, and a hydraulic system for separately delivering hydraulic oil to a lifting cylinder, a tilting cylinder, and a side shifting cylinder through a gear pump via a multi-way valve, wherein a pressure sensor for detecting oil pressure is installed in each of the lifting cylinder, the tilting cylinder, and the side shifting cylinder, and a photoelectric sensor for detecting an operation frequency of the forklift handle is installed on the forklift handle; each of signal ends of the photoelectric sensor and the pressure sensors is connected to an input end of the vehicle control unit, and an output end of the vehicle control unit is connected to the pump motor through a pump motor control unit.
  • the oil pressure of each actuator cylinder is detected by the pressure sensor, and whether the forklift is loaded or not is determined by the change of the oil pressure.
  • the oil pressure of the actuator cylinder is proportional to the load size, so that the load of the forklift can be calculated, and the lifting speed of the actuator cylinder can be calculated according to the stroke and time of the actuator cylinder.
  • the operation frequency of the driver operating the forklift handle is detected by photoelectric sensor, and is compared with the operation frequency in the hydraulic control model. If they are close, the forklift is autonomously controlled to work directly according to the output of the hydraulic control model. If the operation frequency is 20% less than the operation frequency in the hydraulic control model for three consecutive times, the hydraulic control model is deactivated, and the driver needs to manually control the hydraulic system of the forklift to work.
  • the rotational speed of the pump motor is controlled by establishing the hydraulic control model, without the need for the driver to actively control it.
  • the driver manually controls the forklift handle, which is equivalent to turning the hydraulic system on or off, which can thus not only meet the operational efficiency requirements, but also achieving the purpose of energy saving. That is, intelligent identification, precise control and active output of hydraulic performance output suitable for the operating habits of an individual driver are achieved, thereby achieving optimal control, maximizing energy saving and extending the endurance capacity of the battery.
  • a hydraulic control method based on multi-actuation-state data collection comprises the following steps:
  • the forklift's load weight is first detected to determine whether the forklift is unloaded or loaded with goods, and then the forklift is autonomously controlled to work according to an output of a corresponding hydraulic control model. That is, there is a one-to-one correspondence between hydraulic control models and the forklift loads.
  • the operation frequency of the forklift in each actuation state is synchronously detected; and when the operation frequency is 20% less than an operation frequency in the hydraulic control model for three consecutive times, the hydraulic control model is deactivated and the driver needs to manually control the hydraulic system of the forklift to work. That is, the real-time performance parameter output of the hydraulic system of forklift is carried out through manual control.
  • the hydraulic control model comprises the operation frequency, the average values of the performance parameters of the hydraulic system, the control value, and the rotational speed of the pump motor.
  • the actuator cylinder comprises a lifting cylinder, a tilting cylinder and a side shifting cylinder; and the actuation states comprise raising, lowering, forward tilting, backward tilting, left shifting and right shifting operation states of the forklift.
  • the performance parameters of the hydraulic system comprise oil pressure, load, running time, running speed and cylinder stroke of the actuator cylinder.
  • a pressure sensor is installed in the actuator cylinder to detect the oil pressure; and the running speed is calculated according to the running time and stroke of the actuator cylinder.
  • the pump motor is started at this time and then drives the gear pump to supply oil to a multi-way valve, and then supplies oil to the actuator lifting cylinder, so as to lift the goods.
  • a pressure sensor Y1 is set in the lifting cylinder to detect the lifting pressure Y11, Y12, Y13 ... Y1n in real time, then the average oil pressure of the lifting cylinder is:
  • the above performance parameters of the hydraulic system are compared with the preset values, and a final control value is output to control the work, that is, a current or voltage signal is output and fed back to the pump motor control unit to control the rotational speed of the pump motor, thereby establishing a hydraulic control model of the forklift during lifting, in which the operation frequency, the average value of the respective performance parameters of the hydraulic system, the control value, and the rotational speed of the pump motor are included.
  • hydraulic control models are established for the forklift during lowering, forward tilting, backward tilting, left side shifting, and right side shifting in the case that the forklift is unloaded or loaded, respectively.
  • the driver operates the forklift handle, and the vehicle control unit starts the hydraulic system to work after receiving the control signal.
  • the automatic control of the forklift is achieved by establishing a hydraulic control model under each actuation state.
  • the vehicle control unit identifies and outputs a control method that fits the current driver's habitual control, thereby reducing unnecessary high-performance output manipulation, effectively reducing the energy consumption of the whole machine hydraulic system, and increasing the endurance capacity of the battery.
  • a hydraulic system for implementing the hydraulic control method as described above comprises a forklift handle 1, a vehicle control unit 10, a pump motor 2, and a hydraulic system for separately delivering hydraulic oil to a lifting cylinder 6, a tilting cylinder 7, and a side shifting cylinder 8 through a gear pump 4 via a multi-way valve 5.
  • a pressure sensor 9 for detecting oil pressure is installed in each of the lifting cylinder 6, the tilting cylinder 7, and the side shifting cylinder 8.
  • a photoelectric sensor for detecting an operation frequency of the forklift handle is installed on the forklift handle 1.
  • Each of signal ends of the photoelectric sensor and the pressure sensors 9 is connected to an input end of the vehicle control unit 10, and an output end of the vehicle control unit 10 is connected to the pump motor 2 through a pump motor control unit 3.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Structural Engineering (AREA)
  • Transportation (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Civil Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Fluid Mechanics (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Analytical Chemistry (AREA)
  • Forklifts And Lifting Vehicles (AREA)

Abstract

Disclosed in the present invention is a hydraulic control method based on multi-actuation-state data collection, comprising: obtaining identity information of a driver; detecting performance parameters of a hydraulic system in each actuation state; after repeating n times, recording and storing an operation frequency and average values of the performance parameters of the hydraulic system; outputting a control value; establishing a hydraulic control model when a forklift is unloaded and a hydraulic control model when the forklift is loaded; and when a driver is identified as the same person, by the hydraulic system of the forklift, autonomously controlling the forklift to work automatically according to an output of the hydraulic control model. In the present invention, the speed of a pump motor is controlled by establishing the hydraulic control model, without the need for the driver to actively control it. The driver manually controls the forklift handle to turn the hydraulic system on or off, which can thus not only meet the operational efficiency requirements, but also achieve the purpose of energy saving.

Description

    Technical field
  • The present invention relates the technical field of forklifts, and specifically to a self-feedback energy control system and a control method for a heavy-duty electric forklift hydraulic system based on multi-actuation-state data collection.
    • Technical background
  • Heavy-duty electric forklifts generally refer to electric forklifts loading 6 tons or more. They use batteries as power to drive motors and hydraulic systems to work, achieving walking, loading and unloading functions. Heavy-duty electric forklifts are heavy in themselves, and the weight of the whole machine is even greater after loading, so the power required for work is also large. Due to the limitation that all major systems in the overall layout of the machine will occupy a certain space, the size of the power battery cannot be designed to be very large, resulting in a limited endurance capacity of the battery.
  • Most of forklift operations will achieve load changes within a certain range below a rated load or operate at a fixed load. However, since the forklift is operated by different drivers at different time periods, and each person has different operating habits, for example, the strength of operating the handle, pedal, throttle, etc., the speed of action or the length of time are all different. This results in the forklift's Vehicle Control Unit (VCU) needing to re-formulate a hydraulic performance working strategy for each operation, for example, the speed of the pump motor, the oil output of the hydraulic pump, the pressure of the hydraulic oil, etc., are different, so that the hydraulic performance is completely controlled by the driver subjectively, and the VCU has a heavy workload and does not save energy.
  • A hydraulic control model of the present invention proposes an optimal control strategy for the hydraulic system by collecting and processing hydraulic performance parameters of different drivers in different actuation states, and autonomously outputs required hydraulic performance under a set expected actuation state. At this time, the driver controls the hydraulic action only by inputting a signal and does not participate in controlling the rotational speed of the motor, entering an autonomous control state, so that the hydraulic action output of the whole vehicle best fits the current driver's working habits.
  • In combination with a face recognition function, the present invention has got the function of independently collecting the individual operating habits of multiple people on the vehicle. The entire process of each driver's driving control habits is recorded into a data dot matrix. Then, according to a driver's identity, the person's operating habit recommendation mode is automatically switched, and a set point triggering the operating habits is identified to implement active control.
    • Summary
  • An objective of the present invention is to provide a hydraulic system and a control method based on multi-actuation-state data collection. Therefore, the operating habits can be collected to the maximum extent possible, and the working state of each actuator cylinder is fixed to an operation state that can meet the operational efficiency requirements, and can also save energy and adapt to the driver's habits.
  • A specific technical solution of the present invention is as follows:
  • A hydraulic control method based on multi-actuation-state data collection, comprising the following steps:
    • S1. obtaining identity information of a driver;
    • S2. when a forklift is unloaded, operating a forklift handle to make each actuator cylinder enter an actuation state in sequence, and then separately detecting performance parameters of a hydraulic system in each actuation state;
    • S3. after repeating n times, recording and storing an operation frequency of the forklift in each actuation state and average values of the performance parameters of the hydraulic system;
    • S4. comparing an average value of a running speed among the performance parameters of the hydraulic system with a preset value, and if a difference is greater than a specified value, replacing the average value with the preset value and outputting the former as a control value;
    • S5. after processing the control value in step S4, outputting a current or voltage signal and feeding the same back to a pump motor control unit to control a rotational speed of a pump motor; thereby establishing a hydraulic control model when the forklift is unloaded;
    • S6. loading different weights of goods onto the forklift, and in the same manner as steps S2-S5, establishing a hydraulic control model when the forklift is loaded; and
    • S7. when a driver is identified as the same person in step S1, once the driver operates the forklift handle, by the hydraulic system of the forklift, autonomously controlling the forklift to work automatically according to an output of the hydraulic control model in step S5 or S6.
  • In a further solution, the hydraulic control model comprises the operation frequency, the average values of the performance parameters of the hydraulic system, the control value, and the rotational speed of the pump motor.
  • In a further solution, in step S7, once the driver operates the forklift handle, the operation frequency of the forklift in each actuation state is synchronously detected; and when the operation frequency is 20% less than an operation frequency in the hydraulic control model for three consecutive times, the hydraulic control model is deactivated and the driver needs to manually control the hydraulic system of the forklift to work.
  • In a further solution, in step S7, after the driver operates the forklift handle, the forklift's load weight is first detected to determine whether the forklift is unloaded or loaded with goods, and then the forklift is autonomously controlled to work according to an output of a corresponding hydraulic control model.
  • In a further solution, in step S2, the actuator cylinder comprises a lifting cylinder, a tilting cylinder and a side shifting cylinder; and the actuation states comprise raising, lowering, forward tilting, backward tilting, left shifting and right shifting operation states of the forklift.
  • In a further solution, in step S2, the performance parameters of the hydraulic system comprise oil pressure, load, running time, running speed and cylinder stroke of the actuator cylinder.
  • In a further solution, the specified value in step S4 means that: a specified value for a lifting speed is ±30 mm/s, a specified value for a tilting speed is 1.2°/s, and a specified value for a side shifting speed is ±9 mm/s.
  • In a further solution, a pressure sensor is installed in the actuator cylinder to detect the oil pressure; and the running speed is calculated according to the running time and stroke of the actuator cylinder.
  • Another inventive objective of the present invention is to provide a hydraulic system for implementing the hydraulic control method described above, comprising a forklift handle, a vehicle control unit, a pump motor, and a hydraulic system for separately delivering hydraulic oil to a lifting cylinder, a tilting cylinder, and a side shifting cylinder through a gear pump via a multi-way valve, wherein a pressure sensor for detecting oil pressure is installed in each of the lifting cylinder, the tilting cylinder, and the side shifting cylinder, and a photoelectric sensor for detecting an operation frequency of the forklift handle is installed on the forklift handle; each of signal ends of the photoelectric sensor and the pressure sensors is connected to an input end of the vehicle control unit, and an output end of the vehicle control unit is connected to the pump motor through a pump motor control unit.
  • In the present invention, the oil pressure of each actuator cylinder is detected by the pressure sensor, and whether the forklift is loaded or not is determined by the change of the oil pressure. The oil pressure of the actuator cylinder is proportional to the load size, so that the load of the forklift can be calculated, and the lifting speed of the actuator cylinder can be calculated according to the stroke and time of the actuator cylinder.
  • In the present invention, the operation frequency of the driver operating the forklift handle is detected by photoelectric sensor, and is compared with the operation frequency in the hydraulic control model. If they are close, the forklift is autonomously controlled to work directly according to the output of the hydraulic control model. If the operation frequency is 20% less than the operation frequency in the hydraulic control model for three consecutive times, the hydraulic control model is deactivated, and the driver needs to manually control the hydraulic system of the forklift to work.
  • In the present invention, the rotational speed of the pump motor is controlled by establishing the hydraulic control model, without the need for the driver to actively control it. The driver manually controls the forklift handle, which is equivalent to turning the hydraulic system on or off, which can thus not only meet the operational efficiency requirements, but also achieving the purpose of energy saving. That is, intelligent identification, precise control and active output of hydraulic performance output suitable for the operating habits of an individual driver are achieved, thereby achieving optimal control, maximizing energy saving and extending the endurance capacity of the battery.
    • Brief description of the drawings
    • Fig. 1 is a block diagram of the principle of a hydraulic system of the present invention; and
    • Fig. 2 is a block diagram of a control method of the present invention.
    Detailed description of the embodiments
  • The technical solutions of the present invention will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all the embodiments. All other embodiments obtained by those of ordinary skill in the art on the basis of the embodiments in the present application without involving inventive skill are all within the scope of protection of the present invention.
    • Embodiment 1:
  • As shown in Fig. 2, a hydraulic control method based on multi-actuation-state data collection comprises the following steps:
    • S1. obtaining identity information of a driver;
    • S2. when a forklift is unloaded, operating a forklift handle to make each actuator cylinder enter an actuation state in sequence, and then separately detecting performance parameters of a hydraulic system in each actuation state;
    • S3. after repeating n times, recording and storing an operation frequency of the forklift in each actuation state and average values of the performance parameters of the hydraulic system,
    • wherein in this embodiment, the number of repetitions n is preferably 10-15 times for each actuator cylinder;
    • S4. comparing an average value of a running speed among the performance parameters of the hydraulic system with a preset value, and if a difference is greater than a specified value, replacing the average value with the preset value and outputting the former as a control value,
    • wherein the specified value means that: a specified value for a lifting speed is ±30 mm/s, a specified value for a tilting speed is 1.2°/s, and a specified value for a side shifting speed is ±9 mm/s;
    • that is, when the forklift is performing a lifting operation, when the difference between the average value of the lifting speed and the preset value is greater than ±30 mm/s, the average value thereof is output as the control value; otherwise, the preset value is output as the control value;
    • when the forklift performs tilting motion, if the difference between the average value of the tilting speed and the preset value is greater than 1.2°/s, the average value thereof is output as the control value; otherwise, the preset value is output as the control value;
    • when the forklift performs side shifting motion, if the difference between the average value of the side shifting speed and the preset value is greater than ±9 mm/s, the average value thereof is output as the control value; otherwise, the preset value is output as the control value;
    • S5. after processing the control value in step S4, outputting a current or voltage signal and feeding the same back to a pump motor control unit to control a rotational speed of a pump motor; thereby establishing a hydraulic control model when the forklift is unloaded;
    • S6. loading different weights of goods onto the forklift, and in the same manner as steps S2-S5, establishing a hydraulic control model when the forklift is loaded; and
    • S7. when a driver is identified as the same person in step S1, once the driver operates the forklift handle, by the hydraulic system of the forklift, autonomously controlling the forklift to work automatically according to an output of the hydraulic control model in step S5 or S6.
  • That is, after the driver operates the forklift handle, the forklift's load weight is first detected to determine whether the forklift is unloaded or loaded with goods, and then the forklift is autonomously controlled to work according to an output of a corresponding hydraulic control model. That is, there is a one-to-one correspondence between hydraulic control models and the forklift loads.
  • Once the driver operates the forklift handle, the operation frequency of the forklift in each actuation state is synchronously detected; and when the operation frequency is 20% less than an operation frequency in the hydraulic control model for three consecutive times, the hydraulic control model is deactivated and the driver needs to manually control the hydraulic system of the forklift to work. That is, the real-time performance parameter output of the hydraulic system of forklift is carried out through manual control.
  • In this embodiment, the hydraulic control model comprises the operation frequency, the average values of the performance parameters of the hydraulic system, the control value, and the rotational speed of the pump motor.
  • The actuator cylinder comprises a lifting cylinder, a tilting cylinder and a side shifting cylinder; and the actuation states comprise raising, lowering, forward tilting, backward tilting, left shifting and right shifting operation states of the forklift.
  • The performance parameters of the hydraulic system comprise oil pressure, load, running time, running speed and cylinder stroke of the actuator cylinder.
  • In a further solution, a pressure sensor is installed in the actuator cylinder to detect the oil pressure; and the running speed is calculated according to the running time and stroke of the actuator cylinder.
  • For example, during the lifting action of the lifting cylinder, when the driver operates the forklift handle to perform the lifting action, the pump motor is started at this time and then drives the gear pump to supply oil to a multi-way valve, and then supplies oil to the actuator lifting cylinder, so as to lift the goods. A pressure sensor Y1 is set in the lifting cylinder to detect the lifting pressure Y11, Y12, Y13 ... Y1n in real time, then the average oil pressure of the lifting cylinder is:
    • Σ lifting pressure [ (Y11+Y12+Y13+......+Y1n) / n ] ; the average forklift load G11, G12, G13 ... G1n is simultaneously recorded and calculated one by one, then
    • Σ lifting load spectrum [ (G11+G12+G13+......+G1n) / n ] ; thereafter, the lifting speed V11, V12, V13 ... V1n of the lifting cylinder is calculated according to the time and cylinder stroke, then Σ lifting speed [ (V11+V12+V13+......+V1n) / n ] , where n described above is the number of times.
  • The above performance parameters of the hydraulic system are compared with the preset values, and a final control value is output to control the work, that is, a current or voltage signal is output and fed back to the pump motor control unit to control the rotational speed of the pump motor, thereby establishing a hydraulic control model of the forklift during lifting, in which the operation frequency, the average value of the respective performance parameters of the hydraulic system, the control value, and the rotational speed of the pump motor are included.
  • Similarly, hydraulic control models are established for the forklift during lowering, forward tilting, backward tilting, left side shifting, and right side shifting in the case that the forklift is unloaded or loaded, respectively.
  • According to the control block diagram in Figure 2, the driver operates the forklift handle, and the vehicle control unit starts the hydraulic system to work after receiving the control signal. The automatic control of the forklift is achieved by establishing a hydraulic control model under each actuation state.
  • In the present invention, through the above control method, the vehicle control unit identifies and outputs a control method that fits the current driver's habitual control, thereby reducing unnecessary high-performance output manipulation, effectively reducing the energy consumption of the whole machine hydraulic system, and increasing the endurance capacity of the battery.
    • Embodiment 2:
  • As shown in Fig. 1, a hydraulic system for implementing the hydraulic control method as described above comprises a forklift handle 1, a vehicle control unit 10, a pump motor 2, and a hydraulic system for separately delivering hydraulic oil to a lifting cylinder 6, a tilting cylinder 7, and a side shifting cylinder 8 through a gear pump 4 via a multi-way valve 5. A pressure sensor 9 for detecting oil pressure is installed in each of the lifting cylinder 6, the tilting cylinder 7, and the side shifting cylinder 8. A photoelectric sensor for detecting an operation frequency of the forklift handle is installed on the forklift handle 1. Each of signal ends of the photoelectric sensor and the pressure sensors 9 is connected to an input end of the vehicle control unit 10, and an output end of the vehicle control unit 10 is connected to the pump motor 2 through a pump motor control unit 3.
  • Although this specification is described in accordance with implementations, not every implementation contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims (9)

  1. A hydraulic control method based on multi-actuation-state data collection, characterized in that the hydraulic control method comprises the following steps:
    S1. obtaining identity information of a driver;
    S2. when a forklift is unloaded, operating a forklift handle to make each actuator cylinder enter an actuation state in sequence, and then separately detecting performance parameters of a hydraulic system in each actuation state;
    S3. after repeating n times, recording and storing an operation frequency of the forklift in each actuation state and average values of the performance parameters of the hydraulic system;
    S4. comparing an average value of a running speed among the performance parameters of the hydraulic system with a preset value, and if a difference is greater than a specified value, replacing the average value with the preset value and outputting the former as a control value;
    S5. after processing the control value in step S4, outputting a current or voltage signal and feeding the same back to a pump motor control unit to control a rotational speed of a pump motor; thereby establishing a hydraulic control model when the forklift is unloaded;
    S6. loading different weights of goods onto the forklift, and in the same manner as steps S2-S5, establishing a hydraulic control model when the forklift is loaded; and
    S7. when a driver is identified as the same person in step S1, once the driver operates the forklift handle, by the hydraulic system of the forklift, autonomously controlling the forklift to work automatically according to an output of the hydraulic control model in step S5 or S6.
  2. The hydraulic control method according to claim 1, characterized in that the hydraulic control model comprises the operation frequency, the average values of the performance parameters of the hydraulic system, the control value, and the rotational speed of the pump motor.
  3. The hydraulic control method according to claim 1, characterized in that in step S7, once the driver operates the forklift handle, the operation frequency of the forklift in each actuation state is synchronously detected; and when the operation frequency is 20% less than an operation frequency in the hydraulic control model for three consecutive times, the hydraulic control model is deactivated and the hydraulic system of the forklift is manually controlled.
  4. The hydraulic control method according to claim 1, characterized in that after the driver operates the forklift handle, the forklift's load weight is first detected to determine whether the forklift is unloaded or loaded with goods, and then the forklift is autonomously controlled to work according to an output of a corresponding hydraulic control model.
  5. The hydraulic control method according to claim 1, characterized in that the actuator cylinder comprises a lifting cylinder, a tilting cylinder and a side shifting cylinder; and the actuation states comprise raising, lowering, forward tilting, backward tilting, left shifting and right shifting operation states of the forklift.
  6. The hydraulic control method according to claim 1, characterized in that the performance parameters of the hydraulic system comprise oil pressure, load, running time, running speed and cylinder stroke of the actuator cylinder.
  7. The hydraulic control method according to claim 6, characterized in that a pressure sensor is installed in the actuator cylinder to detect the oil pressure; and the running speed is calculated according to the running time and stroke of the actuator cylinder.
  8. The hydraulic control method according to claim 6, characterized in that the specified value in step S4 means that: a specified value for a lifting speed is ±30 mm/s, a specified value for a tilting speed is 1.2°/s, and a specified value for a side shifting speed is ±9 mm/s.
  9. A hydraulic system for implementing the hydraulic control method according to any one of claims 1 to 8, comprising a forklift handle (1), a vehicle control unit (10), a pump motor (2), and a hydraulic system for separately delivering hydraulic oil to a lifting cylinder (6), a tilting cylinder (7), and a side shifting cylinder (8) through a gear pump (4) via a multi-way valve (5), characterized in that a pressure sensor (9) for detecting oil pressure is installed in each of the lifting cylinder (6), the tilting cylinder (7), and the side shifting cylinder (8), and a photoelectric sensor for detecting an operation frequency of the forklift handle is installed on the forklift handle (1); each of signal ends of the photoelectric sensor and the pressure sensors (9) is connected to an input end of the vehicle control unit (10), and an output end of the vehicle control unit (10) is connected to the pump motor (2) through a pump motor control unit (3).
EP24921604.5A 2024-03-26 2024-11-06 HYDRAULIC SYSTEM AND HYDRAULIC CONTROL METHOD BASED ON DATA COLLECTION ACROSS MULTIPLE EXECUTION STATUS Pending EP4692567A4 (en)

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PCT/CN2024/130178 WO2025161580A1 (en) 2024-03-26 2024-11-06 Hydraulic system and hydraulic control method based on multi-execution-state data collection

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CN106335454A (en) * 2016-09-29 2017-01-18 北京汽车股份有限公司 Vehicle and setting method of vehicle driving habit of driver
CN109026867A (en) * 2018-09-25 2018-12-18 杭叉集团股份有限公司 The energy-saving hydraulic system of large-tonnage storage battery forktruck
CN110683488A (en) * 2019-09-29 2020-01-14 浙江事倍达物流设备有限公司 Intelligent electric engineering vehicle and control method thereof
CN111103871A (en) * 2020-01-03 2020-05-05 圣点世纪科技股份有限公司 Automobile auxiliary driving control method based on finger vein recognition
CN112141962A (en) * 2020-10-20 2020-12-29 安徽合力股份有限公司 Hydraulic control system and control method for electric forklift
CN112455418A (en) * 2020-11-27 2021-03-09 厦门理工学院 Automatic driving energy-saving auxiliary system of diesel fork lift truck and control method thereof
KR102416201B1 (en) * 2021-03-04 2022-07-05 주식회사 알씨엔 Autonomous Drive Control System for Electric Forklift of Autonomous or Manual
CN116923622A (en) * 2023-07-26 2023-10-24 依米克车业（昆山）有限公司 Intelligent power control method for electric bicycle
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