Hydraulic control system and method

Abstract

The embodiment of the invention discloses a hydraulic control system and method. The hydraulic control system comprises a main controller and at least two hydraulic subsystems, and the main controller is in communication connection with the hydraulic subsystems; each hydraulic subsystem comprises at least two oil cylinders, and the main controller is used for controlling the working states of the oil cylinders so as to cooperatively control the oil cylinders. According to the hydraulic control system and method provided by the embodiment of the invention, cooperative control can be realized, and the control reliability is ensured.

Description

Technical Field

[0001] The embodiments of the present invention relate to hydraulic control technology, and more particularly to a hydraulic control system and method. Background Technology

[0002] Hydraulic systems are mechanical systems that use liquid as the working medium and transmit energy through hydrostatic pressure to achieve power transmission, motion control, or force amplification. They can provide high power and stable control and are widely used in fields requiring large loads or precision motion. Currently, existing hydraulic control systems suffer from reliability issues. Summary of the Invention

[0003] This invention provides a hydraulic control system and method to achieve coordinated control and ensure control reliability.

[0004] In a first aspect, embodiments of the present invention provide a hydraulic control system, comprising: a main controller and at least two hydraulic subsystems, wherein the main controller is communicatively connected to each of the hydraulic subsystems; each of the hydraulic subsystems includes at least two hydraulic cylinders, and the main controller is used to control the working state of the hydraulic cylinders to coordinate the control of multiple hydraulic cylinders.

[0005] Optionally, the total number of cylinders is even, and all cylinders are grouped in pairs. The two cylinders in the same group are the upper cylinder and the lower cylinder, and the two cylinders in the same group are located in the same hydraulic subsystem. The main controller is used to control the coordinated movement of all upper cylinders and the coordinated movement of all lower cylinders.

[0006] Optionally, the hydraulic subsystem further includes a slave controller, which is communicatively connected to the master controller; the slave controller is used to receive control signals from the master controller and control the working state of the hydraulic cylinder according to the control signals.

[0007] Optionally, the hydraulic subsystem further includes at least two variable frequency motors, each corresponding to one of the oil cylinders, and the oil cylinders are electrically connected to the slave controller through the corresponding variable frequency motors.

[0008] Optionally, the hydraulic control system further includes at least two encoders, each encoder corresponding to one of the hydraulic cylinders, and the hydraulic cylinders are electrically connected to the slave controller through the corresponding encoders.

[0009] Optionally, the hydraulic control system further includes multiple load detection units, each corresponding to one of the hydraulic cylinders. The load detection units are electrically connected to the main controller and are used to detect the load status of the corresponding hydraulic cylinder.

[0010] In a second aspect, embodiments of the present invention provide a hydraulic control method, wherein the hydraulic control method is executed by a main controller as described in the first aspect, the hydraulic control method comprising:

[0011] Receive control commands;

[0012] The operating state of the hydraulic cylinders is controlled according to the control commands to coordinate the control of multiple hydraulic cylinders.

[0013] Optionally, the operating state of the control cylinder includes:

[0014] Control all upper cylinders to move up or down, or control all lower cylinders to move up or down;

[0015] Receive displacement information from each of the hydraulic cylinders;

[0016] The motion state of the hydraulic cylinder is adjusted based on the displacement information.

[0017] Optionally, adjusting the motion state of the hydraulic cylinder based on the displacement information includes:

[0018] If the moving cylinder is an upper cylinder, and at least two of the upper cylinders have asynchronous displacements, then the displacement of the cylinder is adjusted so that all the upper cylinders move in tandem.

[0019] If the moving cylinder is a lower cylinder, and at least two of the lower cylinders have asynchronous displacements, then the displacement of the cylinder is adjusted so that all the lower cylinders move in tandem.

[0020] Optionally, the operating state of the control cylinder includes:

[0021] If a cylinder needs to be switched for load, control the unloaded cylinder to rise and the loaded cylinder to fall.

[0022] The hydraulic control system and method provided in this invention include: a main controller and at least two hydraulic subsystems. The main controller is communicatively connected to each hydraulic subsystem. Each hydraulic subsystem includes at least two cylinders. The main controller controls the working state of the cylinders to achieve coordinated control of multiple cylinders. The hydraulic control system and method provided in this invention control the working state of the cylinders in each hydraulic subsystem through the communication connection between the main controller and the hydraulic subsystems. The main controller controls the cylinders in the hydraulic subsystems that need to move to move in coordination with the cylinders in other hydraulic subsystems. For example, if at least one cylinder has a different displacement than the other cylinders, the main controller adjusts the displacement of the cylinders to achieve coordinated control of multiple cylinders and ensure control reliability. Attached Figure Description

[0023] Figure 1 This is a structural block diagram of a hydraulic control system provided in Embodiment 1 of the present invention;

[0024] Figure 2 This is a schematic diagram of a hydraulic cylinder provided in Embodiment 2 of the present invention;

[0025] Figure 3 This is a schematic diagram of a circuit containing a hydraulic cylinder provided in Embodiment 2 of the present invention;

[0026] Figure 4 This is a structural block diagram of a hydraulic control system provided in Embodiment 2 of the present invention;

[0027] Figure 5 This is a flowchart of a hydraulic control method provided in Embodiment 3 of the present invention. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0029] Example 1

[0030] Figure 1 This is a structural block diagram of a hydraulic control system provided in Embodiment 1 of the present invention. (Reference) Figure 1 The hydraulic control system includes a main controller 10 and at least two hydraulic subsystems 20. The main controller 10 is communicatively connected to each hydraulic subsystem 20. Each hydraulic subsystem 20 includes at least two cylinders. The main controller 10 is used to control the working state of the cylinders to coordinate the control of multiple cylinders.

[0031] Specifically, there can be two or more hydraulic subsystems 20, and each hydraulic subsystem 20 can include two or more cylinders. Taking a hydraulic subsystem 20 including multiple cylinders as an example, at a certain moment, the main controller 10 controls a portion of the cylinders (the cylinders that need to move) in the hydraulic subsystem 20 to move in coordination with a portion of the cylinders (the cylinders that need to move) in other hydraulic subsystems 20, or the main controller 10 controls another portion of the cylinders (the cylinders that need to move) in the hydraulic subsystem 20 to move in coordination with another portion of the cylinders (the cylinders that need to move) in other hydraulic subsystems 20. For example, when at least one cylinder has a different displacement than the other cylinders, the main controller 10 adjusts the displacement of the cylinders to ensure that the synchronization error between the cylinders does not exceed a preset threshold, such as 2mm. In other words, the main controller 10 can control all the cylinders that need to move to move in coordination, realizing coordinated control of multiple cylinders.

[0032] It should be noted that the number of hydraulic subsystems 20 and the number of cylinders included in each hydraulic subsystem 20 in this embodiment can be determined according to the actual hydraulic control system requirements, and are not limited here.

[0033] The hydraulic control system provided in this embodiment includes: a main controller and at least two hydraulic subsystems. The main controller is communicatively connected to each hydraulic subsystem. Each hydraulic subsystem includes at least two cylinders. The main controller is used to control the working state of the cylinders to achieve coordinated control of multiple cylinders. The hydraulic control system provided in this embodiment controls the working state of the cylinders in each hydraulic subsystem through the main controller's communicative connection. The main controller controls the cylinders in the hydraulic subsystems that need to move to move in coordination with cylinders in other hydraulic subsystems. For example, if at least one cylinder has a different displacement than the other cylinders, the main controller adjusts the cylinder's displacement to achieve coordinated control of multiple cylinders and ensure control reliability.

[0034] Example 2

[0035] This embodiment is based on Embodiment 1. Figure 2 This is a schematic diagram of a hydraulic cylinder provided in Embodiment 2 of the present invention. Figure 3 This is a schematic diagram of a circuit containing a hydraulic cylinder according to Embodiment 2 of the present invention. (Reference) Figure 2 , Figure 3 Optionally, the total number of cylinders is even, and all cylinders are grouped in pairs. The two cylinders in the same group are the upper cylinder and the lower cylinder, and the two cylinders in the same group are located in the same hydraulic subsystem. The main controller 10 is used to control the coordinated movement of all upper cylinders and the coordinated movement of all lower cylinders.

[0036] Specifically, taking each hydraulic subsystem 20 as an example, which includes four cylinders, the four cylinders in each hydraulic subsystem 20 are divided into two groups, with two cylinders in each group. The two cylinders in each group are the upper cylinder and the lower cylinder, respectively. The upper and lower cylinders in the same group work in parallel, alternating between upper and lower cylinders. Figure 2 As shown, both the upper cylinder A1 and the lower cylinder A2 in the same group are equipped with an opening and closing nut B and a hollow rotating platform C, and use the same precision-rolled threaded steel bar D. At a certain moment, the main controller 10 controls all the upper cylinders to move in coordination, or the main controller 10 controls all the lower cylinders to move in coordination. When all the upper cylinders need to move, the main controller 10 controls all the upper cylinders to move in coordination; when all the lower cylinders need to move, the main controller 10 controls all the lower cylinders to move in coordination.

[0037] In one implementation, one cylinder can be selected as the master cylinder from all the upper cylinders, and the others as auxiliary cylinders. Similarly, one cylinder can be selected as the master cylinder from all the lower cylinders, and the others as auxiliary cylinders. The master cylinders in the upper and lower cylinders can be in the same hydraulic subsystem or in different hydraulic subsystems. In the same-side cylinder master-auxiliary cylinder cooperative mode: the master and auxiliary cylinders are controlled by a variable frequency motor (variable frequency drive) to adjust the hydraulic pump speed, achieving a stepped flow output. To match the flow characteristics, a regulating valve (proportional valve) is installed in the cylinder's switching valve circuit. Mechanical limiting ensures that the discrete flow output of the switching valve is constrained to be basically consistent. To prevent the cylinder from stalling during lowering, a balance valve is added to the circuit. The coordinated control is achieved through a dual closed loop: the encoder of the hydraulic cylinder collects displacement signals in real time, the controller calculates the reference displacement of the main and auxiliary hydraulic cylinders based on the running speed setpoint, and then dynamically calculates the displacement following error of the main and auxiliary hydraulic cylinders through PID control, generates speed compensation commands and converts them into motor frequency signals, and finally relies on PID parameter self-tuning to enable the main and auxiliary hydraulic cylinders to accurately follow the target displacement throughout the entire operation, achieving ±2mm level synchronous accuracy control.

[0038] Figure 4 This is a structural block diagram of a hydraulic control system provided in Embodiment 2 of the present invention. (Reference) Figure 4 Optionally, the hydraulic subsystem also includes a slave controller 21, which is communicatively connected to the master controller 10. The slave controller 21 is used to receive control signals from the master controller 10 and control the working state of the cylinder according to the control signals.

[0039] Specifically, each hydraulic subsystem 20 includes a slave controller 21, which can transmit displacement information of all cylinders in its hydraulic subsystem 20 to the master controller 10. Furthermore, the slave controller 21 controls the coordinated movement of all lower cylinders in its hydraulic subsystem 20, or controls the coordinated movement of all upper cylinders in its hydraulic subsystem 20, according to the control signals transmitted by the master controller 10.

[0040] Optionally, the hydraulic subsystem 20 also includes at least two variable frequency motors 22, each corresponding to a hydraulic cylinder, and the hydraulic cylinder is electrically connected to the controller 21 through the corresponding variable frequency motor 22.

[0041] Specifically, the number of variable frequency motors 22 is the same as the number of hydraulic cylinders. The controller 21 can control the working state and frequency of the variable frequency motors 22. When the variable frequency motors 22 rotate, they drive the corresponding hydraulic cylinders to move. Furthermore, the frequency of the variable frequency motors 22 is adjustable, achieving smooth speed adjustment under different frequency power supplies, while ensuring operating efficiency and reliability. The working principle of the variable frequency motors 22 is electromagnetic induction. The stator windings of the variable frequency motors 22 are input with adjustable frequency AC power, which can be converted from industrial frequency AC power (such as 220V / 380V, 50Hz). The stator windings of the variable frequency motors 22 generate a rotating magnetic field. The rotational speed of the rotating magnetic field is proportional to the frequency of the AC power input to the stator windings of the variable frequency motors 22. Under the action of the rotating magnetic field, the rotor of the variable frequency motor 22 generates an induced current, which in turn is driven to rotate by electromagnetic force. By adjusting the frequency of the AC power, the motor speed can be changed. The variable frequency motor 22 includes a common variable frequency asynchronous motor, a vector control variable frequency motor, and a permanent magnet synchronous variable frequency motor. The common variable frequency asynchronous motor has a simple structure, moderate cost, and a wide speed range. The vector control variable frequency motor adopts a high-precision encoder, supports closed-loop control, and has high speed regulation accuracy and large low-speed torque. The rotor of the permanent magnet synchronous variable frequency motor contains permanent magnets, which makes it more efficient (5%-10% higher than that of the asynchronous motor), smaller in size, and lower in energy consumption. In this embodiment, the variable frequency motor can be a common variable frequency asynchronous motor, which is determined according to the actual hydraulic control system requirements and is not limited here.

[0042] Furthermore, the hydraulic subsystem also includes a hydraulic pump, through which the variable frequency motor controls the movement of the hydraulic cylinder. The hydraulic pump converts the mechanical energy of the variable frequency motor into the pressure energy of the hydraulic oil, providing a high-pressure oil source for the hydraulic subsystem. The operation of the hydraulic pump is based on volume changes to achieve oil suction and pressure. Essentially, it completes energy conversion through the periodic volume changes of the sealed working chamber. The specific process consists of two steps: Suction: The volume of the pump's working chamber increases, creating a negative pressure within the chamber. Hydraulic oil from the tank, under atmospheric pressure, enters the working chamber through the suction pipe. Pressure: The volume of the working chamber decreases, the oil within the chamber is squeezed, and the pressure increases. The high-pressure oil is then delivered to the hydraulic cylinder through the pressure pipe and a check valve. Different types of hydraulic pumps vary significantly in pressure, flow characteristics, and applicable scenarios. Hydraulic pumps include gear pumps, vane pumps, and piston pumps. Gear pumps have a simple structure, low cost, and strong resistance to contamination, but their pressure and flow pulsation is relatively large. Vane pumps have uniform flow, low noise, and stable operation, but their resistance to contamination is weaker, and their pressure is moderate. Piston pumps have high pressure (up to 30MPa or more), high efficiency, and flexible flow adjustment, but their structure is complex and their cost is high. The specific type of hydraulic pump used in this embodiment can be determined according to the actual hydraulic control system requirements and is not limited here.

[0043] In addition, the rated pressure, displacement, flow rate, and efficiency of the hydraulic pump affect the system's power performance; the rated frequency range, speed ratio, rated torque, and efficiency of the variable frequency motor directly affect the speed regulation effect and operational stability. The rated pressure of a hydraulic pump is the highest pressure it can output during long-term stable operation; it must be matched to the system's required working pressure to avoid overpressure damage. The displacement of a hydraulic pump is the theoretical volume of oil discharged per revolution (unit: mL / r); a larger displacement results in a larger output flow rate at the same speed. The flow rate of a hydraulic pump is the volume of oil pumped per unit time (unit: L / min); the flow rate determines the movement speed of the actuator. The efficiency of a hydraulic pump includes volumetric efficiency (the ratio of actual flow rate to theoretical flow rate) and mechanical efficiency (the ratio of output hydraulic power to input mechanical power); higher efficiency means lower energy loss. The rated frequency range, speed ratio, rated torque, and efficiency of the variable frequency motor directly affect the speed regulation effect and operational stability. The rated frequency range of a variable frequency motor is the frequency range in which it can operate stably, covering the speed regulation requirements of actual applications (e.g., 5-50Hz, 10-100Hz). The speed ratio of a variable frequency motor is the ratio of its highest rated speed to its lowest rated speed; a larger ratio indicates a wider speed regulation range. The rated torque of a variable frequency motor is the torque output at its rated speed, meeting the torque requirements for load startup and operation, especially at low speeds (to avoid insufficient torque at low speeds). The efficiency of a variable frequency motor is the ratio of its output mechanical power to its input electrical power. High-efficiency variable frequency motors reduce long-term energy consumption, making them particularly suitable for scenarios requiring continuous operation.

[0044] Optionally, the hydraulic control system also includes at least two encoders 23, each encoder 23 corresponding to a hydraulic cylinder, and the hydraulic cylinder is electrically connected to the slave controller 21 through the corresponding encoder 23.

[0045] Specifically, the number of encoders 23 is the same as the number of hydraulic cylinders. The encoders 23 collect the displacement information of the corresponding hydraulic cylinders and transmit the collected displacement information to the slave controller 21. The slave controller 21 can transmit the received displacement information to the master controller 10, so that the master controller 10 can adjust the displacement of the hydraulic cylinders according to the displacement information of the hydraulic cylinders, thereby realizing the coordinated control of the hydraulic cylinders.

[0046] Furthermore, an encoder is a device that converts rotary or linear displacement into digital or analog electrical signals. Its core function is to achieve precise conversion between position, speed, and electrical signals, providing cylinder displacement information to the hydraulic control system. Encoders achieve their function by sensing displacement and encoding it for output. While the principles of different types of encoders vary slightly, the core logic remains the same. Mechanical / Optical Sensing: Rotary encoders typically include a code disk (with scales / light-passing holes) and a read head (photoelectric / electromagnetic sensor); linear encoders use a scale and read head in conjunction. Displacement Trigger Signal: When the code disk (or scale) of a rotary encoder moves with the target, the read head detects the scale change, generating a periodic pulse signal or level change. Signal Processing Output: After shaping and counting the raw signal, the encoder outputs a digital quantity (such as pulse count, binary code) or an analog quantity, corresponding to the cylinder displacement information. Encoders can be classified into incremental encoders and absolute encoders based on their output signal type. Incremental encoders output continuous pulses, requiring counting to determine position. They are simple in structure and low in cost, but displacement information is lost after power failure. Absolute encoders, on the other hand, have a unique code (such as binary or Gray code) for each position; displacement information is not lost after power failure, resulting in higher accuracy. Furthermore, encoders can be classified into rotary encoders (measuring angle / speed) and linear encoders (measuring linear displacement) based on their measurement method. The specific type of encoder in this embodiment can be determined according to the actual needs of the hydraulic control system and is not limited here.

[0047] Furthermore, the encoder's resolution, accuracy, response speed, and signal output method directly affect positioning accuracy and control performance. Encoder resolution is the smallest recognizable unit of displacement, typically expressed in pulses per revolution (incremental encoders) or bits (e.g., 16-bit, 20-bit) (absolute encoders). Higher resolution results in better accuracy. Encoder accuracy is the deviation between the actual and measured positions, usually expressed in arcminutes, arcseconds (rotary encoders), or micrometers (linear encoders). Encoder response speed is the maximum measurable motion speed; exceeding this speed will result in signal loss, requiring matching with the actual movement speed of the hydraulic cylinder. Encoder signal output methods include open collector, differential signal, and push-pull output, which must be compatible with the slave controller interface.

[0048] Optionally, the hydraulic control system also includes multiple load detection units 30, each corresponding to a hydraulic cylinder. The load detection units 30 are electrically connected to the main controller 10 and are used to detect the load status of the corresponding hydraulic cylinder.

[0049] Specifically, the load detection unit 30 can be a load sensor. The load sensor can detect the load pressure on the hydraulic cylinder and generate a corresponding electrical signal. The main controller 10 determines the load size of the hydraulic cylinder based on the electrical signal transmitted by the load sensor, thereby adjusting the load on the hydraulic cylinder. The load sensor can convert physical loads such as tension, pressure, and torque into measurable electrical signals. Its core function is to realize the quantitative monitoring and data output of the load. The core of the load sensor is based on the strain effect, which is the key to realizing the conversion of load into electrical signals. Strain gauges are attached to the surface of a metal elastomer and form a Wheatstone bridge circuit. When the elastomer is subjected to a load, it undergoes a small deformation, which drives the strain gauges to stretch or compress synchronously, causing a change in the resistance value of the strain gauges. The change in resistance breaks the balance of the bridge and outputs a weak voltage signal. After amplification, filtering, and other processing, a standard electrical signal (such as voltage or current) proportional to the load size is obtained. Load sensors include tensile sensors, pressure sensors, torque sensors, and load cells. Tensile sensors can detect tensile loads and have tensile-resistant structures; pressure sensors focus on compressive load detection, and the force-bearing surface is mostly planar or curved; torque sensors are for detecting torsional loads on rotating parts and need to rotate synchronously with the rotating shaft; load cells are used to optimize the detection of gravity (weight) loads and have high accuracy. In this embodiment, the load sensor can be a pressure load sensor. The range, accuracy, response speed, and environmental adaptability of the load sensor affect its detection performance. The range of the load sensor is the maximum load value that the load sensor can accurately detect, which needs to cover the load range in actual applications to avoid overload damage; the accuracy of the load sensor is the degree of deviation between the load sensor's detected value and the actual load, usually expressed as a percentage of full-scale error; the response speed of the load sensor is the time it takes for the load sensor to output a stable signal from the point of bearing the load, which should be given priority in high-speed motion scenarios; the environmental adaptability of the load sensor is its ability to resist temperature drift, moisture, and vibration, and sensors with special protection levels should be selected for harsh environments such as high-temperature environments.

[0050] The hydraulic control system provided in this embodiment includes: a main controller and at least two hydraulic subsystems. The main controller is communicatively connected to each hydraulic subsystem. Each hydraulic subsystem includes at least two cylinders. The main controller is used to control the working state of the cylinders to coordinate the control of multiple cylinders. The total number of cylinders is even. All cylinders are grouped in pairs. The two cylinders in the same group are the upper cylinder and the lower cylinder, and the two cylinders in the same group are located in the same hydraulic subsystem. The main controller is used to control the coordinated movement of all upper cylinders and the coordinated movement of all lower cylinders. The hydraulic subsystem also includes a slave controller, which is communicatively connected to the main controller. The slave controller is used to receive control signals from the main controller and control the working state of the cylinders according to the control signals. The hydraulic subsystem also includes at least two variable frequency motors, each corresponding to a cylinder. The cylinders are electrically connected to the slave controller through their corresponding variable frequency motors. The hydraulic subsystem also includes at least two encoders, each corresponding to a cylinder. The cylinders are electrically connected to the variable frequency motors through their corresponding encoders. The hydraulic control system provided in this embodiment communicates with the slave controllers of each hydraulic subsystem through a main controller to control the working state of the cylinders in each hydraulic subsystem. The main controller controls the cylinders in the hydraulic subsystem that need to move to move in coordination with the cylinders in other hydraulic subsystems that need to move. For example, when at least one cylinder has a different displacement from the other cylinders, the main controller adjusts the displacement of the cylinders through the slave controllers to achieve coordinated control of multiple cylinders and ensure control reliability.

[0051] Example 3

[0052] Figure 5 This is a flowchart of a hydraulic control method provided in Embodiment 3 of the present invention. This embodiment can be applied to hydraulic control of oil cylinders, etc. The method can be executed by the main controller in the hydraulic control system described in any embodiment of the present invention. The controller can be implemented in software and / or hardware. The method specifically includes the following steps:

[0053] Step 110: Receive control commands.

[0054] The control commands can be input externally to the main controller in the hydraulic control system. Taking a hydraulic subsystem consisting of four cylinders as an example, the four cylinders in each subsystem are divided into two groups of two cylinders each. Each group consists of an upper cylinder and a lower cylinder. The upper and lower cylinders in the same group operate in parallel, alternating between upper and lower cylinders. The control commands can include commands requiring the movement of all upper cylinders, or commands requiring the movement of all lower cylinders.

[0055] Step 120: According to the control command, control the working state of the hydraulic cylinders to coordinate the control of multiple hydraulic cylinders, specifically including:

[0056] Control all upper cylinders to move up or down, or control all lower cylinders to move up or down;

[0057] Receive displacement information from each hydraulic cylinder;

[0058] Based on the displacement information, the motion state of the hydraulic cylinder is adjusted, specifically including:

[0059] If the moving cylinder is the upper cylinder, and at least two of the upper cylinders have asynchronous displacements, then adjust the displacement of the cylinders to make all the upper cylinders move in sync.

[0060] If the moving cylinder is a lower cylinder, and at least two of the lower cylinders have asynchronous displacements, then adjust the displacement of the cylinders to make all the lower cylinders move in sync.

[0061] The main controller controls all upper cylinders to move up or down, or all lower cylinders to move up or down, according to control commands. When the control command requires all upper cylinders to move up (down), the main controller controls all upper cylinders to move up (down). When the control command requires all lower cylinders to move up (down), the main controller controls all lower cylinders to move up (down).

[0062] In addition, when the main controller controls the movement of the hydraulic cylinders, it first dynamically adjusts the load state of the cylinders, and then controls the cylinders to lift or lower synchronously. When the main controller adjusts the load state of the hydraulic cylinders, if the upper and lower cylinders need to switch loads, it controls the unloaded cylinders to lift and fine-tune, and the loaded cylinders to lower and fine-tune, controlling the cylinder load imbalance to be less than or equal to 2 MPa.

[0063] It should be noted that the specific duration of the preset time in this embodiment can be determined according to actual control requirements, and is not limited here.

[0064] The hydraulic control method provided in this embodiment controls the working state of the cylinders in each hydraulic subsystem according to the control command, such as controlling all upper cylinders to move in coordination or controlling all lower cylinders to move in coordination. When there are at least two cylinders whose displacements are not synchronized, the displacement of the cylinders is adjusted to achieve coordinated control of multiple cylinders and ensure control reliability.

[0065] Example 4

[0066] Embodiment 4 of the present invention provides a computer-readable storage medium storing a computer program thereon. When executed by a main controller, the program implements the hydraulic control method provided in the embodiments of the present invention, the method comprising:

[0067] Receive control commands;

[0068] The operating state of the hydraulic cylinders is controlled according to the control commands, so as to coordinate the control of multiple hydraulic cylinders.

[0069] The computer storage medium of this invention can be any combination of one or more computer-readable media. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0070] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0071] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including—but not limited to—wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0072] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or terminal. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0073] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, rearrangements, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A hydraulic control system, characterized in that, include: The system includes a main controller and at least two hydraulic subsystems, with the main controller communicatively connected to each of the hydraulic subsystems. Each of the hydraulic subsystems includes at least two hydraulic cylinders, and the main controller is used to control the working state of the hydraulic cylinders to coordinate the control of multiple hydraulic cylinders.

2. The hydraulic control system according to claim 1, characterized in that, The total number of cylinders is even, and all cylinders are grouped in pairs. The two cylinders in the same group are the upper cylinder and the lower cylinder, and the two cylinders in the same group are located in the same hydraulic subsystem. The main controller is used to control the coordinated movement of all upper cylinders and the coordinated movement of all lower cylinders.

3. The hydraulic control system according to claim 1, characterized in that, The hydraulic subsystem also includes a slave controller, which is communicatively connected to the master controller. The slave controller is used to receive control signals from the master controller and control the working state of the hydraulic cylinder according to the control signals.

4. The hydraulic control system according to claim 3, characterized in that, The hydraulic subsystem also includes at least two variable frequency motors, each corresponding to a hydraulic cylinder, and the hydraulic cylinder is electrically connected to the slave controller through the corresponding variable frequency motor.

5. The hydraulic control system according to claim 3, characterized in that, It also includes at least two encoders, each corresponding to one of the hydraulic cylinders, and the hydraulic cylinders are electrically connected to the slave controller through the corresponding encoders.

6. The hydraulic control system according to claim 1, characterized in that, It also includes multiple load detection units, each corresponding to one of the hydraulic cylinders. Each load detection unit is electrically connected to the main controller and is used to detect the load status of the corresponding hydraulic cylinder.

7. A hydraulic control method, characterized in that, The hydraulic control method is executed by the main controller as described in any one of claims 1-6, and the hydraulic control method includes: Receive control commands; The operating state of the hydraulic cylinders is controlled according to the control commands to coordinate the control of multiple hydraulic cylinders.

8. The hydraulic control method according to claim 7, characterized in that, The operating states of the control cylinder include: Control all upper cylinders to move up or down, or control all lower cylinders to move up or down; Receive displacement information from each of the hydraulic cylinders; The motion state of the hydraulic cylinder is adjusted based on the displacement information.

9. The hydraulic control method according to claim 8, characterized in that, The step of adjusting the motion state of the hydraulic cylinder based on the displacement information includes: If the moving cylinder is an upper cylinder, and at least two of the upper cylinders have asynchronous displacements, then the displacement of the cylinder is adjusted so that all the upper cylinders move in tandem. If the moving cylinder is a lower cylinder, and at least two of the lower cylinders have asynchronous displacements, then the displacement of the cylinder is adjusted so that all the lower cylinders move in tandem.

10. The hydraulic control method according to claim 7, characterized in that, The operating states of the control cylinder include: If a cylinder needs to be switched for load, control the unloaded cylinder to rise and the loaded cylinder to fall.

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