Hydraulic servo valve control system

Abstract

The invention provides a hydraulic servo valve control system which comprises a single chip microcomputer used for conducting steady state control on the operation process of hydraulic equipment. The power supply voltage reduction module is used for connecting an external power supply and providing a stabilized power supply for system work; the servo valve output module is electrically connected with the single-chip microcomputer, and the AD sampling module is electrically connected with the single-chip microcomputer and used for preventing the single-chip microcomputer from being burnt due to too high input voltage; and the 485 communication module is connected with the single chip microcomputer and is used for receiving and sending data. Based on the STM32F030 single-chip microcomputer, digital quantity PI calculation real-time control is adopted, a traditional analog quantity control mode is replaced, remote communication is achieved through the 485 communication module, networking control can be achieved, and the system is more intelligent and user-friendly.

Description

Technical Field

[0001] This disclosure relates to the field of servo valve control technology, and in particular to a hydraulic servo valve control system. Background Technology

[0002] A hydraulic servo valve is a hydraulic control valve whose output and input quantities have a certain functional relationship and can respond quickly. It is an important component of a hydraulic servo system.

[0003] Hydraulic servo valves are controlled by hydraulic control boards, but existing hydraulic control boards are inconvenient to debug and have unintuitive displays, making them unsuitable for applications with high control requirements. Summary of the Invention

[0004] This disclosure provides a hydraulic servo valve control system to solve one of the technical problems recognized by the inventors.

[0005] This disclosure provides a hydraulic servo valve control system, including:

[0006] A microcontroller is used for steady-state control of the operation of hydraulic equipment.

[0007] The power step-down module is used to connect to an external power source and provide a regulated power supply for system operation;

[0008] The servo valve output module is electrically connected to the microcontroller and includes a servo valve drive output circuit, an output current sampling circuit, and a short-circuit protection circuit. The servo valve drive output circuit is used to drive the servo valve to work, the output current sampling circuit is used to sample the signal to enter the microcontroller, and the short-circuit protection circuit prevents the microcontroller from burning out due to excessive input voltage.

[0009] The AD sampling module is electrically connected to the microcontroller to prevent the microcontroller from burning out due to excessive input voltage.

[0010] The 485 communication module is connected to the microcontroller and is used to receive and send data.

[0011] Preferably, the servo valve drive output circuit includes a first servo valve drive output circuit and a second servo valve drive output circuit. The first servo valve drive output circuit includes a resistor R57, one end of which is connected to the base of transistor Q1. A resistor R58 and a capacitor C57 are connected in parallel between the base and emitter of transistor Q1. The emitter of transistor Q1 is grounded. The collector of transistor Q1 is connected to one end of a resistor R59. The other end of a resistor R59 is connected to the base of transistor Q2. A resistor R60 and a capacitor C58 are connected in parallel between the base and emitter of transistor Q2. The emitter of transistor Q2 is connected to the second pin of transistor Q5. The collector of transistor Q2 is connected to the first pin of transistor Q5. The third pin of transistor Q5 is connected to the positive terminal of the servo valve. A diode D14 and a resistor R61 are connected in parallel to the negative terminal of the servo valve. The first servo valve drive output circuit and the second servo valve drive output circuit have the same structure.

[0012] Preferably, the output current sampling circuit includes amplifiers U12A and U12B. A resistor R80 is connected to the first pin of amplifier U12A, and a capacitor C77 and a diode D1 are connected to the resistor R80. A resistor R78 and a resistor R66 are connected to the second pin of amplifier U12A, with one end of resistor R78 grounded and one end of resistor R66 connected to the first pin of amplifier U12A. A resistor R76 and a capacitor C75 are connected to the third pin of amplifier U12A. A short-circuit protection circuit is connected between the first pin of U12A and the seventh pin of amplifier U12B. A resistor R79 is connected to the seventh pin of amplifier U12B. A capacitor C76 and a diode D2 are connected to the resistor R79. A resistor R77 and a resistor R49 are connected to the sixth pin of amplifier U12B. One end of resistor R77 is grounded, and one end of resistor R49 is connected to the seventh pin of amplifier U12B. A resistor R75 and a capacitor C74 are connected to the fifth pin of amplifier U12B.

[0013] Preferably, the short-circuit protection circuit includes comparator U8A and comparator U8B. The second pin of comparator U8A is connected to the first pin of amplifier U12A through resistor R67. A capacitor C60 is connected to the second pin of comparator U8A. Resistors R68 and R59 are connected to the third pin of comparator U8A. One end of resistor R69 is connected to the first pin of comparator U8A. Resistor R70, capacitor C62, and diode D16 are connected to the first pin of comparator U8A. The first pin of comparator U8A is connected to the seventh pin of comparator U8B. Resistor R50 and capacitor C59 are connected to the sixth pin of comparator U8B. One end of resistor R50 is connected to the seventh pin of amplifier U12B. Resistor R51 and capacitor C53 are connected to the fifth pin of comparator U8B. Resistor R52 is connected to the fifth pin of comparator U8B. One end of resistor R52 is connected to the seventh pin of comparator U8B.

[0014] Preferably, the AD sampling module includes a first AD sampling module, a second AD sampling module, and a third AD sampling module. The three AD sampling modules have the same structure. The first AD sampling module includes an amplifier U4A. Resistors R21 and R10 are connected in series between the first and fourth pins of the amplifier U4A. One end of the resistor R21 is connected to a resistor R24. One end of the resistor R24 ​​is connected to a resistor R46, a capacitor C30, and a diode D7. The third pin of the amplifier U4A is connected to a resistor R20. One end of the resistor R20 is connected to a diode D10, a capacitor C47, and a resistor R19. One end of the resistor R19 is connected to a capacitor C44 and a resistor R9.

[0015] Preferably, the 485 communication module includes a chip U7, a common-mode inductor L4, and a TVS diode D5. A resistor R8 is connected to the first pin of chip U7. The second and third pins of chip U7 are connected together. A resistor R36 is connected to the third pin of chip U7. One end of resistor R36 is connected to resistor R35. A resistor R37 is connected to the fourth pin of chip U7. One end of resistor R37 is connected to resistor R34. Resistors R34 and R35 are connected together. The fifth pin of chip U7 is grounded. The sixth and seventh pins of chip U7 are respectively connected to the common-mode inductor L4. The common-mode inductor L4 is connected to the TVS diode D5. A resistor R39, a capacitor C35, and a resistor R48 are connected between the common-mode inductor L4 and the sixth pin of chip U7. A resistor R38, a capacitor C34, and a resistor R47 are connected between the common-mode inductor L4 and the seventh pin of chip U7.

[0016] Preferably, the power step-down module includes a first power step-down unit, a second power step-down unit, and a third power step-down unit. The first power step-down unit reduces the 24V to 48V power supply to 12V through a voltage regulator chip U1 and outputs it to the second power step-down unit. The second power step-down unit reduces the 12V power supply to 5V through a voltage regulator chip U3 and outputs it to the third power step-down unit. The third power step-down unit reduces the 5V voltage to 3.3V to supply the system for operation.

[0017] Preferably, it also includes an LCD display module, which is connected to the microcontroller and the power supply buck module respectively. The LCD display module includes a button interface and an LCD communication interface.

[0018] Preferably, the button interface includes a SHIFT button, a DOWN button, an UP button, an ENTER button, and a PRO button, and the SHIFT button, DOWN button, UP button, ENTER button, and PRO button are respectively connected to capacitors C8, C7, C4, C5, and C6.

[0019] The main beneficial effects of this disclosure are as follows: This invention is based on the STM32F030 microcontroller and adopts digital PI calculation real-time control to replace the traditional analog control method. Furthermore, it achieves remote communication through the 485 communication module, enabling network control and making it more intelligent and user-friendly.

[0020] It should be understood that both the foregoing general description and the following detailed description are for illustrative purposes and do not necessarily limit the scope of this disclosure. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the subject matter of this disclosure. Furthermore, the specification and drawings serve to explain the principles of this disclosure. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the specific embodiments of this disclosure or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a block diagram of the servo valve control system according to an embodiment of the present disclosure;

[0023] Figure 2 This is a microcontroller circuit diagram of an embodiment of this disclosure;

[0024] Figure 3 This is a circuit diagram of the servo valve drive circuit according to an embodiment of the present disclosure;

[0025] Figure 4 This is a circuit diagram of the output current sampling circuit and short-circuit protection circuit according to an embodiment of the present disclosure;

[0026] Figure 5 This is a circuit diagram of the AD sampling module according to an embodiment of the present disclosure;

[0027] Figure 6 This is a circuit diagram of the 485 communication module according to an embodiment of the present disclosure;

[0028] Figure 7 This is a circuit diagram of the first power supply step-down unit according to an embodiment of the present disclosure;

[0029] Figure 8 This is a circuit diagram of the second power supply step-down unit according to an embodiment of the present disclosure;

[0030] Figure 9 This is a circuit diagram of the third power supply step-down unit according to an embodiment of the present disclosure;

[0031] Figure 10 This is a circuit diagram of an LCD display module according to an embodiment of the present disclosure; Detailed Implementation

[0032] The technical solutions of this disclosure will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments.

[0033] Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this disclosure.

[0034] In the description of this disclosure, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0036] Example

[0037] like Figure 1-10 As shown, this embodiment provides a hydraulic servo valve control system, including a microcontroller for steady-state control of the hydraulic equipment's operation. In this embodiment, the existing STM32F030 microcontroller is used for steady-state control of the hydraulic equipment's operation, suitable for controlling all direct-acting and pilot-operated, overflow-type proportional pressure and flow valves without electrical position feedback. A power supply step-down module is used to connect to an external power source to provide regulated power for system operation. A servo valve output module, electrically connected to the microcontroller, includes a servo valve drive output circuit, an output current sampling circuit, and a short-circuit protection circuit. The servo valve drive output circuit drives the servo valve, the output current sampling circuit samples the signal to the microcontroller, and the short-circuit protection circuit prevents excessive input voltage from burning out the microcontroller. An AD sampling module, also electrically connected to the microcontroller, prevents excessive input voltage from burning out the microcontroller. A 485 communication module, connected to the microcontroller, is used to receive and send data.

[0038] like Figure 3 As shown, Figure 3 This is a circuit diagram of a servo valve drive output circuit. The servo valve drive output circuit includes a first servo valve drive output circuit and a second servo valve drive output circuit. The first servo valve drive output circuit includes a resistor R57. One end of the resistor R57 is connected to the base of a transistor Q1. A resistor R58 and a capacitor C57 are connected in parallel between the base and emitter of the transistor Q1. The emitter of the transistor Q1 is grounded. The collector of the transistor Q1 is connected to one end of a resistor R59. The other end of the resistor R59... The base of transistor Q2 is connected to the first terminal. A resistor R60 and a capacitor C58 are connected in parallel between the base and emitter of transistor Q2. The emitter of transistor Q2 is connected to the second pin of transistor Q5. The collector of transistor Q2 is connected to the first pin of transistor Q5. The third pin of transistor Q5 is connected to the positive terminal of servo valve. A diode D14 and a resistor R61 are connected in parallel to the negative terminal of servo valve. The first servo valve drive output circuit and the second servo valve drive output circuit have the same structure.

[0039] In this embodiment, the servo valve drive output circuit has two paths: a first servo valve drive output circuit and a second servo valve drive output circuit. Figure 3As shown, the two inputs are A01 and A02. Taking the first servo valve drive output circuit as an example, the A01 pulse signal controls the transistor Q1 through the current-limiting resistor R57. When the A01 pulse signal is high, the transistor Q1 is turned on and grounded, and the transistor Q2 is turned on through the current-limiting resistor R59. The turn on of the transistor Q2 controls the turn on of the transistor Q5. The servo valve is connected to F+ and F-. When the transistor Q5 is turned on, the servo valve starts to work. The resistor R61 is used to sample the current of the servo valve. The diode D14 is to prevent the transistor Q5 from being damaged when it is turned on and off. The resistor R58 and the capacitor C57 mainly play the role of anti-interference.

[0040] Furthermore, the structure and principle of the second servo valve drive output circuit are the same as those of the first servo valve drive output circuit, and will not be described in detail here.

[0041] like Figure 4 As shown, the output current sampling circuit includes amplifiers U12A and U12B. A resistor R80 is connected to the first pin of amplifier U12A, and a capacitor C77 and a diode D1 are connected to resistor R80. Resistors R78 and R66 are connected to the second pin of amplifier U12A, with one end of resistor R78 grounded and one end of resistor R66 connected to the first pin of amplifier U12A. A resistor R76 and a capacitor C75 are connected to the third pin of amplifier U12A. A short-circuit protection circuit is connected between the first pin of amplifier U12A and the seventh pin of amplifier U12B. A resistor R79 is connected to the seventh pin of amplifier U12B, which in turn is connected to a capacitor C76 and a diode D2. Resistors R77 and R49 are connected to the sixth pin of amplifier U12B. One end of resistor R77 is grounded, and one end of resistor R49 is connected to the seventh pin of amplifier U12B. Resistors R75 and C74 are connected to the fifth pin of amplifier U12B. The output current sampling circuit mainly consists of an amplifier and filtering resistors and capacitors. The current sampling resistor R61 of the servo valve is filtered by resistor R76 and capacitor C75 before being input to the third pin of amplifier U12A. The signal is amplified by resistors R78 and R66 and then filtered by resistor R80 and capacitor C77. Finally, the sampled signal directly enters the microcontroller. Diode D1 prevents the microcontroller from burning out due to excessive input voltage.

[0042] like Figure 4As shown, the short-circuit protection circuit includes comparator U8A and comparator U8B. The second pin of comparator U8A is connected to the first pin of amplifier U12A through resistor R67. Capacitor C60 is connected to the second pin of comparator U8A. Resistors R68 and R59 are connected to the third pin of comparator U8A. One end of resistor R69 is connected to the first pin of comparator U8A. Resistor R70, capacitor C62, and diode D16 are connected to the first pin of comparator U8A. The first pin of comparator U8A is connected to the seventh pin of comparator U8B. Resistor R50 and capacitor C59 are connected to the sixth pin of comparator U8B. One end of resistor R50 is connected to the seventh pin of amplifier U12B. Resistor R51 and capacitor C53 are connected to the fifth pin of comparator U8B. Resistor R52 is connected to the fifth pin of comparator U8B. One end of resistor R52 is connected to the seventh pin of comparator U8B. The short-circuit protection circuit mainly consists of a comparator and filter resistors and capacitors. The output current of the servo valve is amplified by the amplifier and then filtered by resistor R67 and capacitor C60 before being input to comparator U8A. When the sampled value of the output current is greater than 3.3V, comparator U8A outputs a low level and transmits the signal to the microcontroller. The microcontroller immediately stops outputting and reports a fault. Resistor R70 and capacitor C62 serve as filters to prevent interference, and diode D16 prevents the microcontroller from burning out due to excessive input voltage.

[0043] like Figure 5As shown, the AD sampling module includes a first AD sampling module, a second AD sampling module, and a third AD sampling module. The three AD sampling modules have the same structure. The first AD sampling module includes an amplifier U4A. Resistors R21 and R10 are connected in series between the first and fourth pins of the amplifier U4A. One end of resistor R21 is connected to resistor R24. One end of resistor R24 ​​is connected to resistor R46, capacitor C30, and diode D7. The third pin of the amplifier U4A is connected to resistor R20. One end of resistor R20 is connected to diode D10, capacitor C47, and resistor R19. One end of resistor R19 is connected to capacitor C44 and resistor R9. The AD sampling module mainly consists of amplifiers and filter resistors and capacitors. It has three analog input channels. The amplifiers used are LM2904 amplifiers, each amplifier having two analog input channels. This embodiment uses two amplifiers. Taking one of the AD sampling modules as an example, the input range is 0-10V. FVin, after being filtered by resistor R9, capacitor C44, resistor R19, and capacitor C47, is input to the third pin of amplifier U4A. The first pin of amplifier U4A outputs the sampling signal, which, after being filtered by resistor R24, resistor R46, and capacitor C30, is input to the microcontroller. Diode D7 prevents the microcontroller from burning out due to excessive input voltage. The structure and principle of the other two channels are the same as the example above, and will not be described in detail here.

[0044] like Figure 6As shown, the 485 communication module includes a chip U7, a common-mode inductor L4, and a TVS diode D5. A resistor R8 is connected to the first pin of chip U7. The second and third pins of chip U7 are connected together. A resistor R36 is connected to the third pin of chip U7. One end of resistor R36 is connected to resistor R35. A resistor R37 is connected to the fourth pin of chip U7. One end of resistor R37 is connected to resistor R34. Resistors R34 and R35 are connected together. The fifth pin of chip U7 is grounded. The sixth and seventh pins of chip U7 are respectively connected to the common-mode inductor L4. The common-mode inductor L4 is connected to the TVS diode D5. A resistor R39, a capacitor C35, and a resistor R48 are connected between the common-mode inductor L4 and the sixth pin of chip U7. A resistor R38, a capacitor C34, and a resistor R47 are connected between the common-mode inductor L4 and the seventh pin of chip U7. In this embodiment, resistors R47 and R48, capacitors C34, C35, and C67 are used to ensure that the SP485 chip U7 is in an idle state when there is no connection, providing network failure protection and improving the reliability of the RS485 node and the network. Common-mode inductor L4 and TVS diode D5 are used to protect the RS485 bus from external interference and improve the circuit's EMI performance. Pull-up resistors R8, R34, and R35 ensure data stability in the communication idle state. RTC1 is the RS485 transmit / receive control pin, TX1 is the data transmit pin, and RX1 is the data receive pin. When RTC1 is high, communication is in data transmit mode; when RTC1 is low, communication is in data receive mode.

[0045] like Figure 7-9 As shown, the power buck module includes a first power buck unit, a second power buck unit, and a third power buck unit. The first power buck unit uses a voltage regulator chip U1 to reduce the 24V to 48V power supply to 12V and output it to the second power buck unit. The second power buck unit uses a voltage regulator chip U3 to reduce the 12V power supply to 5V and output it to the third power buck unit. The third power buck unit reduces the 5V voltage to 3.3V to supply the system for operation.

[0046] Specifically, the first power supply step-down unit mainly consists of a voltage regulator chip U1 and filter capacitors. The external input power is 24VDC-48VDC. The external input power PV+ passes through filter capacitors C2 and C10 and then enters the voltage regulator chip U1. After feedback from inductor L2 and diode D4, and filtering by capacitors C11, C3, and C9, a stable +12V power supply is output. The second power supply step-down unit mainly consists of a voltage regulator chip U2 and filter capacitors. The +12V after being stepped down by the first power supply step-down unit is filtered by voltage regulator chip U3 and capacitors C79, C14, C15, and C71, and finally outputs a stable +5V power supply. The third power supply step-down unit includes a voltage regulator chip U5 and filter capacitors. The +5V is filtered by voltage regulator chip U5 and capacitors C21, C23, C22, and C29, and finally outputs a stable +3.3V power supply for use by internal circuits such as microcontrollers.

[0047] like Figure 10 As shown, it also includes an LCD display module, which is connected to the microcontroller and the power supply step-down module respectively. The LCD display module includes a button interface and an LCD communication interface.

[0048] Specifically, the button interface includes a SHIFT button, a DOWN button, an UP button, an ENTER button, and a PRO button. Each of these buttons is connected to capacitors C8, C7, C4, C5, and C6, respectively. The button interface, composed of SHIFT, DOWN, UP, ENTER, and PRO buttons, incorporates filter capacitors C4, C5, C6, C7, and C8. The filter capacitors prevent jitter interference from affecting the button signals. The microcontroller communicates with the LCD via I2C, using the SDA and SCL pins. RST is the LCD's reset pin, and AK is the LCD's backlight control pin.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure.

Claims

1. A hydraulic servo valve control system, characterized in that, include: A microcontroller is used for steady-state control of the operation of hydraulic equipment. The power step-down module is used to connect to an external power source and provide a regulated power supply for system operation; The servo valve output module is electrically connected to the microcontroller and includes a servo valve drive output circuit, an output current sampling circuit, and a short-circuit protection circuit. The servo valve drive output circuit is used to drive the servo valve to work, the output current sampling circuit is used to sample the signal to enter the microcontroller, and the short-circuit protection circuit prevents the microcontroller from burning out due to excessive input voltage. The AD sampling module is electrically connected to the microcontroller to prevent the microcontroller from burning out due to excessive input voltage. The 485 communication module is connected to the microcontroller and is used to receive and send data.

2. The hydraulic servo valve control system according to claim 1, characterized in that, The servo valve drive output circuit includes a first servo valve drive output circuit and a second servo valve drive output circuit. The first servo valve drive output circuit includes a resistor R57. One end of the resistor R57 is connected to the base of transistor Q1. A resistor R58 and a capacitor C57 are connected in parallel between the base and emitter of transistor Q1. The emitter of transistor Q1 is grounded. One end of the collector of transistor Q1 is connected to a resistor R59. The other end of the resistor R59 is connected to the base of transistor Q2. A resistor R60 and a capacitor C58 are connected in parallel between the base and emitter of transistor Q2. The emitter of transistor Q2 is connected to the second pin of transistor Q5. The collector of transistor Q2 is connected to the first pin of transistor Q5. The third pin of transistor Q5 is connected to the positive terminal of the servo valve. A diode D14 and a resistor R61 are connected in parallel to the negative terminal of the servo valve. The first servo valve drive output circuit and the second servo valve drive output circuit have the same structure.

3. A hydraulic servo valve control system according to claim 2, characterized in that, The output current sampling circuit includes amplifiers U12A and U12B. A resistor R80 is connected to the first pin of amplifier U12A, which is connected to capacitor C77 and diode D1. A resistor R78 and resistor R66 are connected to the second pin of amplifier U12A. One end of resistor R78 is grounded, and one end of resistor R66 is connected to the first pin of amplifier U12A. A resistor R76 and capacitor C75 are connected to the third pin of amplifier U12A. The short-circuit protection circuit is connected between the first pin of 2A and the seventh pin of amplifier U12B. The seventh pin of amplifier U12B is connected to resistor R79, which is connected to capacitor C76 and diode D2. The sixth pin of amplifier U12B is connected to resistors R77 and R49. One end of resistor R77 is grounded, and one end of resistor R49 is connected to the seventh pin of amplifier U12B. The fifth pin of amplifier U12B is connected to resistor R75 and capacitor C74.

4. A hydraulic servo valve control system according to claim 3, characterized in that, The short-circuit protection circuit includes comparator U8A and comparator U8B. The second pin of comparator U8A is connected to the first pin of amplifier U12A through resistor R67. Capacitor C60 is connected to the second pin of comparator U8A. Resistors R68 and R59 are connected to the third pin of comparator U8A. One end of resistor R69 is connected to the first pin of comparator U8A. Resistor R70, capacitor C62, and diode D16 are connected to the first pin of comparator U8A. The first pin of comparator U8A is connected to the seventh pin of comparator U8B. Resistor R50 and capacitor C59 are connected to the sixth pin of comparator U8B. One end of resistor R50 is connected to the seventh pin of amplifier U12B. Resistor R51 and capacitor C53 are connected to the fifth pin of comparator U8B. Resistor R52 is connected to the fifth pin of comparator U8B. One end of resistor R52 is connected to the seventh pin of comparator U8B.

5. A hydraulic servo valve control system according to claim 1, characterized in that, The AD sampling module includes a first AD sampling module, a second AD sampling module, and a third AD sampling module. The three AD sampling modules have the same structure. The first AD sampling module includes an amplifier U4A. Resistors R21 and R10 are connected in series between the first and fourth pins of the amplifier U4A. One end of the resistor R21 is connected to a resistor R24. One end of the resistor R24 ​​is connected to a resistor R46, a capacitor C30, and a diode D7. The third pin of the amplifier U4A is connected to a resistor R20. One end of the resistor R20 is connected to a diode D10, a capacitor C47, and a resistor R19. One end of the resistor R19 is connected to a capacitor C44 and a resistor R9.

6. A hydraulic servo valve control system according to claim 1, characterized in that, The 485 communication module includes a chip U7, a common-mode inductor L4, and a TVS diode D5. A resistor R8 is connected to the first pin of chip U7. The second and third pins of chip U7 are connected together. A resistor R36 is connected to the third pin of chip U7. One end of resistor R36 is connected to resistor R35. A resistor R37 is connected to the fourth pin of chip U7. One end of resistor R37 is connected to resistor R34. Resistors R34 and R35 are connected together. The fifth pin of chip U7 is grounded. The sixth and seventh pins of chip U7 are connected to the common-mode inductor L4, which is connected to the TVS diode D5. A resistor R39, a capacitor C35, and a resistor R48 are connected between the common-mode inductor L4 and the sixth pin of chip U7. A resistor R38, a capacitor C34, and a resistor R47 are connected between the common-mode inductor L4 and the seventh pin of chip U7.

7. A hydraulic servo valve control system according to claim 1, characterized in that, The power step-down module includes a first power step-down unit, a second power step-down unit, and a third power step-down unit. The first power step-down unit uses a voltage regulator chip U1 to step down the 24V to 48V power supply to 12V and output it to the second power step-down unit. The second power step-down unit uses a voltage regulator chip U3 to step down the 12V power supply to 5V and output it to the third power step-down unit. The third power step-down unit reduces the 5V voltage to 3.3V to supply the system for operation.

8. A hydraulic servo valve control system according to claim 1, characterized in that, It also includes an LCD display module, which is connected to the microcontroller and the power supply step-down module respectively. The LCD display module includes a button interface and an LCD communication interface.

9. A hydraulic servo valve control system according to claim 8, characterized in that, The button interface includes a SHIFT button, a DOWN button, an UP button, an ENTER button, and a PRO button. The SHIFT button, DOWN button, UP button, ENTER button, and PRO button are respectively connected to capacitors C8, C7, C4, C5, and C6.

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