A proportional direction valve control driving device based on forward and reverse switching

Abstract

The application relates to a proportional direction valve control driving device based on forward-reverse switching, and belongs to the technical field of proportional direction valve control driving, which solves the problems that the proportional direction valve switching control driving device is mostly one-way driving and the circuit structure is complex. The device comprises a forward-reverse switching circuit, which is used for judging the positive and negative nature of a received analog given control signal; if the analog given control signal is positive, an analog feedback control circuit keeps a positive rotation working mode; if the analog given control signal is negative, the analog feedback control circuit is switched to a reverse rotation working mode; the analog feedback control circuit generates a first deviation control signal and a positive valve driving signal of a proportional direction valve based on an analog given control signal and a current sampling signal obtained from a positive connection terminal of the proportional direction valve when being in the positive rotation working mode; and the analog feedback control circuit generates a second deviation control signal and a reverse valve driving signal of the proportional direction valve based on the analog given control signal and a current sampling signal obtained from a negative connection terminal of the proportional direction valve when being in the reverse rotation working mode.

Description

Technical Field

[0001] This invention relates to the field of proportional directional valve switching control drive device technology, and in particular to a proportional directional valve control drive device based on forward and reverse switching. Background Technology

[0002] With the continuous development of modern science and technology, hydraulic technology has gradually matured. In particular, electro-hydraulic control technology, which combines electronic and hydraulic technologies, has accelerated the development of hydraulic technology, enabling hydraulic control to move towards automation and becoming an indispensable and important technical means and link in modern control engineering. Electro-hydraulic proportional directional valves can not only achieve pressure-free, balanced directional switching, but also have the function of remote throttling and speed regulation, representing the development direction of hydraulic directional control. They are widely used in engineering machinery, machining industry, rubber and plastics machinery, metallurgical industry, and other fields.

[0003] Flow control of a proportional valve is achieved by adjusting the position of the core of the proportional directional valve (specifically, the proportional electromagnet within the proportional directional valve) by controlling the current. The proportional valve drive circuit amplifies and modulates the control signal to drive power semiconductor devices to control the current of the proportional directional valve. Currently, drive circuits are broadly classified into analog and digital types. Analog drive circuits use operational amplifiers, PWM generator modules, and current sampling modules to complete the drive circuit design, offering advantages over digital drive circuits such as lower cost, higher reliability, and stronger valve adaptability. However, most widely used analog drive circuits are unidirectional. Furthermore, if existing analog proportional valve control circuits use a current acquisition scheme with sampling resistors, when applied to the control of a three-wire proportional directional valve, since the two valve core electromagnets in a three-wire proportional directional valve share a common terminal O (i.e., terminals A, B, and O), when there is current in AO, the proportional directional valve is controlled to conduct in the forward direction, and when there is current in BO, it is controlled to conduct in the reverse direction. At this point, there will be coupling between the two sampling channels, causing the feedback of the two channels to interfere with each other. Therefore, due to the characteristics of its current sampling circuit, the existing current sampling circuit cannot be directly applied to the proportional commutator drive circuit. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a proportional directional valve control drive device based on forward and reverse switching, in order to solve the problem that existing proportional directional valve switching control drive devices are mostly unidirectional drives and have complex circuit structures.

[0005] This invention provides a proportional directional valve control drive device based on forward and reverse rotation switching, the device comprising:

[0006] The forward / reverse switching circuit is used to determine the forward / reverse nature of the received analog given control signal. If it is forward, the analog feedback control circuit maintains the forward rotation mode; if it is reverse, the analog feedback control circuit is switched to the reverse rotation mode.

[0007] The analog feedback control circuit, when in forward operation mode, generates a first deviation control signal based on the analog given control signal and the current sampling signal obtained from the positive terminal of the proportional directional valve, and generates a forward valve drive signal for the proportional directional valve based on the first deviation control signal; when in reverse operation mode, it generates a second deviation control signal based on the analog given control signal and the current sampling signal obtained from the negative terminal of the proportional directional valve, and generates a reverse valve drive signal for the proportional directional valve based on the second deviation control signal.

[0008] Based on the above solution, the present invention also makes the following improvements:

[0009] Furthermore, the device also includes a digital-to-analog converter circuit.

[0010] The analog given control signal is obtained by converting the corresponding digital given control signal into an analog-to-digital signal using the digital-to-analog converter circuit.

[0011] The corresponding digital given control signal has the same positive and negative polarity as the analog given control signal.

[0012] Furthermore, the forward / reverse switching circuit determines the forward / reverse nature of the received analog given control signal, including:

[0013] If the analog given control signal is less than the reference signal, then the analog given control signal is a positive analog given control signal; so that the analog feedback control circuit can directly process the positive analog given control signal to obtain the positive valve drive signal.

[0014] If the analog given control signal is greater than the reference signal, then the analog given control signal is a reverse analog given control signal; the forward-reverse switching circuit also acquires the difference signal between the reverse analog given control signal and the reference signal; so that the analog feedback control circuit processes the difference signal to obtain the reverse valve drive signal.

[0015] Furthermore, the forward / reverse switching circuit includes: a differential amplifier N4, a comparator N5, a relay K, and resistors R46, R47, R48, and R49; wherein,

[0016] The non-inverting input terminal of the comparator N5 is connected to one end of the normally open contact K-1 and one end of the normally closed contact K-2 of the relay, which is the given signal receiving terminal of the forward / reverse switching circuit and is used to receive the analog given control signal; the output terminal of the differential amplifier N4 is connected to the other end of the normally closed contact K-2, which is the given signal output terminal of the forward / reverse switching circuit.

[0017] The comparator N5 is used to determine the positive or negative nature of the received analog given control signal:

[0018] The inverting input of comparator N5 is connected to a reference voltage; the output is connected to the positive terminal of the control coil of relay K, and the negative terminal of relay K is grounded.

[0019] The differential amplifier N4 is used to output the difference signal between the inverted analog given control signal and the reference signal:

[0020] For differential amplifier N4:

[0021] The non-inverting input terminal is connected to one end of resistor R48 and one end of resistor R49; the other end of resistor R48 is connected to the other end of normally open contact K-1 of relay K.

[0022] The inverting input terminal is connected to one end of resistor R47 and one end of resistor R46; the other end of resistor R47 is grounded, and the other end of resistor R46 is connected to the reference voltage.

[0023] The output of differential amplifier N4 is also connected to the other end of resistor R49;

[0024] The normally open contact K-3 of the relay is connected between the output terminal of the analog feedback control circuit and the positive terminal of the proportional directional valve.

[0025] The normally closed contact K-4 of the relay is connected between the output terminal of the analog feedback control circuit and the negative terminal of the proportional directional valve.

[0026] Furthermore, when in the forward operating mode, relay K does not operate, and normally closed contacts K-2 and K-4, normally open contacts K-1 and K-3 do not operate.

[0027] When in the reverse operating mode, relay K is energized, normally closed contacts K-2 and K-4 are open, and normally open contacts K-1 and K-3 are closed.

[0028] Furthermore, the analog feedback control circuit comprises an analog control circuit, a pulse modulation circuit, an amplification and driving circuit, and a current sampling circuit based on a Hall sensor; wherein,

[0029] The analog control circuit has a control input terminal connected to the given signal output terminal; a feedback terminal connected to the feedback output terminal of the current sampling circuit, used to receive the current sampling signal obtained from the positive terminal of the proportional directional valve when the analog feedback control circuit is in forward operation mode; and also used to receive the current sampling signal obtained from the negative terminal of the proportional directional valve when the analog feedback control circuit is in reverse operation mode; the output terminal is connected to the modulation input terminal of the pulse modulation circuit, used to output a first deviation control signal or a second deviation control signal;

[0030] The pulse modulation circuit has its output terminal connected to the input terminal of the amplification drive circuit.

[0031] The amplifier driver circuit has its output terminal connected to the driver input terminal of the current sampling circuit.

[0032] The current sampling circuit has its drive output terminal connected to the positive terminal of the proportional directional valve via the normally closed contact K-4 of the relay, and also connected to the negative terminal of the proportional directional valve via the normally open contact K-3 of the relay. The common terminal of the proportional directional valve is grounded. The drive output terminal of the current sampling circuit is the output terminal of the analog feedback control circuit.

[0033] Furthermore, the analog control circuit includes operational amplifiers N1A and N1B, resistors R3, R5, R6, R10, R11, R15, R16, and R17, capacitors C3 and C4, and potentiometers RP1 and RP2; wherein,

[0034] One end of resistor R16 is connected to QGND via capacitor C4; the other end of resistor R16 is connected to one end of resistor R15; the other end of resistor R15 is connected to one end of resistor R11 and one fixed end of potentiometer RP2; the other end of resistor R11 is connected to the sliding end of potentiometer RP2 and one end of resistor R17.

[0035] For operational amplifier N1A:

[0036] The inverting input is connected to one end of resistor R15, the non-inverting input is connected to QGND, and the output is connected to one end of resistor R17.

[0037] For operational amplifier N1B:

[0038] The inverting input is connected to the other end of resistor R17, one end of resistor R10 and one end of capacitor C3. The other end of capacitor C3 is connected to the output of operational amplifier N1B. The non-inverting input is connected to QGND via resistor R3.

[0039] The other end of resistor R10 is connected to one end of resistor R6 and the sliding end of potentiometer RP1. The other end of resistor R6 and one fixed end of potentiometer RP1 are both connected to -VEE. The other fixed end of potentiometer RP1 is connected to +VEE via resistor R5.

[0040] One end of the resistor R16 is the control input terminal of the analog control circuit, the inverting input terminal of the operational amplifier N1B is the feedback terminal of the analog control circuit, and the output terminal of the operational amplifier N1B is the output terminal of the analog control circuit.

[0041] Furthermore, the pulse modulation circuit includes a pulse width modulation circuit and a triangular wave generator; wherein,

[0042] The pulse width modulation circuit includes an operational amplifier N2B and resistors R7, R8, R12 and R14;

[0043] For operational amplifier N2B:

[0044] The non-inverting input is connected to one end of resistor R7, and the inverting input is connected to one end of resistor R14; the output is connected to +VEE via resistors R12 and R8 connected in series.

[0045] The other end of resistor R7 is the modulation input terminal of the pulse modulation circuit; the end of resistor R12 connected to resistor R8 is the drive output terminal of the pulse modulation circuit; the other end of resistor 14 is the modulation output terminal of the pulse width modulation circuit.

[0046] The triangular wave generator includes operational amplifiers N3A and N3B, and resistors R13, R18, R22 and R45;

[0047] For operational amplifier N3A:

[0048] The non-inverting input is connected to one end of resistor R13 and one end of resistor R45, the inverting input is connected to QGND, and the output is connected to the other end of resistor R13, one end of resistor R18, and one end of resistor R22.

[0049] For operational amplifier N3B:

[0050] The non-inverting input is connected to QGND, and the inverting input is connected to the other end of resistor R18, the other end of resistor R22, and one end of capacitor C6. The output of operational amplifier N3B is connected to the other end of capacitor C6 and the other end of R45.

[0051] The output terminal of the operational amplifier N3B is the output terminal of the triangular wave generator, which is connected to the modulation output terminal of the pulse width modulation circuit.

[0052] Furthermore, the sampling circuit includes an operational amplifier N2A, a Hall sensor D2, resistors R19, R20, R23, R24, and R25, and capacitors C7 and C8; wherein,

[0053] For operational amplifier N2A:

[0054] The inverting input is connected to one end of resistor R24, one end of resistor R19, and one end of resistor R20, and the other end of resistor R24 ​​is connected to QGND; the non-inverting input is connected to one end of resistor R25, and the output is connected to one end of resistor R23, the other end of resistor R19, and the other end of resistor R20.

[0055] For Hall sensor D2:

[0056] The VIOUT terminal is connected to the other end of resistor R25 and one end of capacitor C8. The BW_SEL terminal, GND terminal, and the other end of capacitor C8 are all connected to QGND. The GND terminal is also connected to one end of capacitor C7. The other end of capacitor C7 and VCC terminal are both connected to the second DC power supply voltage.

[0057] The two IP+ terminals are connected together as the drive input terminals of the current sampling circuit; the two IP- terminals are connected together as the drive output terminals of the current sampling circuit; the other end of resistor R23 is the feedback output terminal of the current sampling circuit.

[0058] Furthermore, the amplification driving circuit includes an amplification driving chip V1, a diode V2, and resistors R26 and R28; wherein,

[0059] The input terminal of the amplifier driver chip V1 is connected to the modulation output terminal of the pulse modulation circuit;

[0060] The output terminal of the amplifier driver chip V1 is connected to the drive input terminal of the current sampling circuit;

[0061] The output of the amplifier driver chip V1 is also connected to the negative terminal of diode V2, and the positive terminal of diode V2 is grounded.

[0062] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0063] The proportional directional valve control drive device based on forward and reverse switching provided by this invention can switch between forward and reverse operating modes of the simulated given control signal by setting a forward and reverse switching circuit. In this way, only one analog feedback control circuit is needed to realize the separate control of forward and reverse rotation of the proportional directional valve control drive device based on forward and reverse switching, which effectively solves the problem that most existing proportional directional valve switching control drive devices are unidirectional drives and cannot realize bidirectional drives, and simplifies the circuit structure of the proportional directional valve switching control drive device.

[0064] Meanwhile, this invention also provides the hardware circuit structure of the forward and reverse switching circuit and the analog feedback control circuit, which does not require software cooperation, and the designed circuit has advantages such as high reliability, low cost and easy maintenance.

[0065] Furthermore, the circuit designed in this invention is small in size and can realize the control of up to 16 proportional directional valves in a 3U standard industrial board, effectively improving the system integration and control capabilities.

[0066] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0067] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0068] Figure 1 This is a schematic diagram of the proportional directional valve control drive device based on forward and reverse switching provided in an embodiment of the present invention;

[0069] Figure 2 This invention provides a schematic diagram of another proportional directional valve control drive device based on forward and reverse switching for embodiments of the present invention. Detailed Implementation

[0070] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0071] A specific embodiment of the present invention discloses a proportional directional valve control drive device based on forward and reverse rotation switching, the structural schematic diagram of which is shown below. Figure 1 and Figure 2 As shown, it includes:

[0072] The forward / reverse switching circuit is used to determine the forward / reverse nature of the received analog given control signal. If it is forward, the analog feedback control circuit maintains the forward rotation mode; if it is reverse, the analog feedback control circuit is switched to the reverse rotation mode.

[0073] The analog feedback control circuit, when in forward operation mode, generates a first deviation control signal based on the analog given control signal and the current sampling signal obtained from the positive terminal of the proportional directional valve, and generates a forward valve drive signal for the proportional directional valve based on the first deviation control signal; when in reverse operation mode, it generates a second deviation control signal based on the analog given control signal and the current sampling signal obtained from the negative terminal of the proportional directional valve, and generates a reverse valve drive signal for the proportional directional valve based on the second deviation control signal.

[0074] Preferably, the device further includes a digital-to-analog converter circuit, wherein the analog given control signal is obtained by converting the corresponding digital given control signal into an analog signal via the digital-to-analog converter circuit; the corresponding digital given control signal and the analog given control signal have the same positive and negative polarity.

[0075] In this embodiment, the upper-layer application controller outputs a digital given control signal through the IIC bus, and the digital-to-analog converter performs digital-to-analog conversion based on the digital given control signal, and outputs an analog control signal corresponding to the digital given control signal.

[0076] Preferably, the digital-to-analog conversion circuit includes a level conversion chip B1, a digital-to-analog chip D1, resistors R1, R2, R4, R21, and capacitors C1, C2, C5; wherein,

[0077] Level conversion chip B1 is used to convert the voltage adapted to the IIC bus into the voltage adapted to the digital-to-analog chip D1; specifically, for chip B1:

[0078] The VDD1 terminal is connected to the first power supply voltage via resistor R3, the GND1 terminal is connected to DGND, and the GND1 terminal is also connected to the first power supply voltage via capacitor C2; the SDA1 terminal is used to receive digital given control signals.

[0079] The VDD2 terminal is directly connected to the second DC power supply voltage, the SDA terminal is connected to the second DC power supply voltage via resistor R1, the GND2 terminal is connected to QGND, and the GND2 terminal is also connected to the second DC power supply voltage via capacitor C2.

[0080] The SDA terminal of chip B1 is also connected to the SDA terminal of chip D1;

[0081] For chip D1:

[0082] The ADDR1, FOR, GND, and ADDR2 terminals are all connected to QGND; the VDD terminal is connected to the second DC power supply voltage, and the VDD terminal is also grounded through capacitor C5. The terminal is connected to the second DC power supply voltage via resistor R21;

[0083] One output terminal of the chip D1 (exemplarily, such as the VoutB terminal) is an analog given control signal output terminal, used to output an analog given control signal.

[0084] After the upper-level application controller outputs a digital setpoint control signal via the IIC bus, the level conversion chip B1 converts the 3.3V level signal of the upper-level controller to a 5V level signal, thereby achieving level matching between the upper-level controller and the digital-to-analog converter chip D1. The IIC bus line between the level conversion chip B1 and the digital-to-analog converter chip D1 is pulled up to 5V through resistors R1 and R2, ensuring that the IIC bus is in an idle state by default. The digital-to-analog converter chip D1 receives the control command (i.e., the "digital setpoint control signal") from the upper-level controller and converts the digital control signal in the range of 0-4095 into an analog control signal of 0-5V. Chip D1 has four output channels; in this invention, one output channel (B) is used to implement the commutation output of the proportional directional valve. A single chip D1 has the capability to control four proportional directional valves.

[0085] Preferably, the forward / reverse switching circuit determines the forward / reverse nature of the received analog given control signal by:

[0086] If the analog given control signal is less than the reference signal, then the analog given control signal is a positive analog given control signal; so that the analog feedback control circuit can directly process the positive analog given control signal to obtain the positive valve drive signal.

[0087] If the analog given control signal is greater than the reference signal, then the analog given control signal is a reverse analog given control signal; the forward-reverse switching circuit also acquires the difference signal between the reverse analog given control signal and the reference signal; so that the analog feedback control circuit processes the difference signal to obtain the reverse valve drive signal.

[0088] Specifically, the forward / reverse switching circuit can be configured as follows:

[0089] The forward / reverse switching circuit includes: a differential amplifier N4, a comparator N5, a relay K, and resistors R46, R47, R48, and R49; wherein,

[0090] The non-inverting input terminal of the comparator N5 is connected to one end of the normally open contact K-1 and one end of the normally closed contact K-2 of the relay, which is the given signal receiving terminal of the forward / reverse switching circuit and is used to receive the analog given control signal; the output terminal of the differential amplifier N4 is connected to the other end of the normally closed contact K-2, which is the given signal output terminal of the forward / reverse switching circuit.

[0091] The comparator N5 is used to determine the positive or negative nature of the received analog given control signal:

[0092] The inverting input of comparator N5 is connected to a reference voltage; the output is connected to the positive terminal of the control coil of relay K, and the negative terminal of relay K is grounded.

[0093] The differential amplifier N4 is used to output the difference signal between the inverted analog given control signal and the reference signal:

[0094] For differential amplifier N4:

[0095] The non-inverting input terminal is connected to one end of resistor R48 and one end of resistor R49; the other end of resistor R48 is connected to the other end of normally open contact K-1 of relay K.

[0096] The inverting input terminal is connected to one end of resistor R47 and one end of resistor R46; the other end of resistor R47 is grounded, and the other end of resistor R46 is connected to the reference voltage.

[0097] The output of differential amplifier N4 is also connected to the other end of resistor R49;

[0098] The normally open contact K-3 of the relay is connected between the output terminal of the analog feedback control circuit and the positive terminal of the proportional directional valve.

[0099] The normally closed contact K-4 of the relay is connected between the output terminal of the analog feedback control circuit and the negative terminal of the proportional directional valve.

[0100] At this time, when in the forward rotation working mode, relay K does not operate, and normally closed contacts K-2 and K-4, normally open contacts K-1 and K-3 do not operate;

[0101] In the reverse operating mode, relay K is energized, normally closed contacts K-2 and K-4 are open, and normally open contacts K-1 and K-3 are closed. If resistors R48 and R49 have equal resistance values, the differential amplifier N5 outputs the difference signal obtained by subtracting the reference voltage from the reverse analog given control signal, and controls the analog feedback control circuit to reverse based on the difference signal.

[0102] Preferably, the analog feedback control circuit comprises an analog control circuit, a pulse modulation circuit, an amplification and driving circuit, and a current sampling circuit based on a Hall sensor; wherein,

[0103] The analog control circuit has a control input terminal connected to the given signal output terminal; a feedback terminal connected to the feedback output terminal of the current sampling circuit, used to receive the current sampling signal obtained from the positive terminal of the proportional directional valve when the analog feedback control circuit is in forward operation mode; and also used to receive the current sampling signal obtained from the negative terminal of the proportional directional valve when the analog feedback control circuit is in reverse operation mode; the output terminal is connected to the modulation input terminal of the pulse modulation circuit, used to output a first deviation control signal or a second deviation control signal;

[0104] The pulse modulation circuit has its output terminal connected to the input terminal of the amplification drive circuit.

[0105] The amplifier driver circuit has its output terminal connected to the driver input terminal of the current sampling circuit.

[0106] The current sampling circuit has its drive output terminal connected to the positive terminal of the proportional directional valve via the normally closed contact K-4 of the relay, and also connected to the negative terminal of the proportional directional valve via the normally open contact K-3 of the relay. The common terminal of the proportional directional valve is grounded. The drive output terminal of the current sampling circuit is the output terminal of the analog feedback control circuit.

[0107] To facilitate better implementation of this solution by those skilled in the art, this embodiment also provides the specific structures of several circuits involved in the positive analog feedback control circuit. Specifically,

[0108] The analog control circuit includes operational amplifiers N1A and N1B, resistors R3, R5, R6, R10, R11, R15, R16, and R17, capacitors C3 and C4, and potentiometers RP1 and RP2. One end of resistor R16 is connected to QGND via capacitor C4; the other end of resistor R16 is connected to one end of resistor R15; the other end of resistor R15 is connected to one end of resistor R11 and one fixed end of potentiometer RP2; the other end of resistor R11 is connected to the sliding end of potentiometer RP2 and one end of resistor R17. For operational amplifier N1A: the inverting input is connected to one end of resistor R15, the non-inverting input is connected to QGND, and the output is connected to one end of resistor R17. For operational amplifier N1B... The inverting input terminal is connected to the other end of resistor R17, one end of resistor R10, and one end of capacitor C3. The other end of capacitor C3 is connected to the output terminal of operational amplifier N1B. The non-inverting input terminal is connected to QGND via resistor R3. The other end of resistor R10 is connected to one end of resistor R6 and the sliding terminal of potentiometer RP1. The other end of resistor R6 and one fixed terminal of potentiometer RP1 are both connected to -VEE. The other fixed terminal of potentiometer RP1 is connected to +VEE via resistor R5. One end of resistor R16 is the control input terminal of the analog control circuit. The inverting input terminal of operational amplifier N1B is the feedback terminal of the analog control circuit. The output terminal of operational amplifier N1B is the output terminal of the analog control circuit.

[0109] The analog control circuit enables real-time PI control of the proportional solenoid valve's control current. The analog given control signal is first connected to the inverting input (pin 2) of operational amplifier N1A via resistor R16 and output from the output (pin 1). Proportional calculation is achieved through parameter matching of resistors R15, R11, and RP2 with R16. The amplification ratio can be adjusted by potentiometer RP2. The proportionally calculated control signal is then input to the inverting input (pin 6) of operational amplifier N1B via resistor R17, and integral calculation is achieved through parameter matching of capacitor C3 and resistor R17. The zero-point adjustment of the PI calculation analog control signal can be achieved by coordinating the parameters of resistor R5, potentiometer RP1, and resistor R6.

[0110] The pulse modulation circuit includes a pulse width modulation circuit and a triangular wave generator; wherein, the pulse width modulation circuit includes an operational amplifier N2B, resistors R7, R8, R12 and R14; for the operational amplifier N2B: the non-inverting input terminal is connected to one end of resistor R7, and the inverting input terminal is connected to one end of resistor R14; the output terminal is connected to +VEE via resistors R12 and R8 connected in series.

[0111] The other end of resistor R7 is the modulation input terminal of the pulse modulation circuit; the end of resistor R12 connected to resistor R8 is the drive output terminal of the pulse modulation circuit; the other end of resistor 14 is the modulation output terminal of the pulse width modulation circuit; the triangular wave generator includes operational amplifiers N3A and N3B, and resistors R13, R18, R22, and R45; for operational amplifier N3A: the non-inverting input terminal is connected to one end of resistor R13 and one end of R45, the inverting input terminal is connected to QGND, and the output terminal is connected to the other end of resistor R13, one end of resistor R18, and one end of resistor R22; for operational amplifier N3B: the non-inverting input terminal is connected to QGND, the inverting input terminal is connected to the other end of resistor R18, the other end of resistor R22, and one end of capacitor C6, and the output terminal of operational amplifier N3B is connected to the other end of capacitor C6 and the other end of R45; the output terminal of operational amplifier N3B is the output terminal of the triangular wave generator and is connected to the modulation output terminal of the pulse width modulation circuit.

[0112] The simulated given control signal undergoes an analog PI calculation in the analog control circuit, and is then output from the output terminal (pin 7) of operational amplifier N1B to the pulse width modulation circuit. N3A and N3B, along with resistors R13, R9, R18, R22, and resistor C6, function as a triangular wave generator. By determining the parameters of capacitor C6, a triangular wave modulated carrier with a frequency of 200Hz is generated. The analog control signal after the PI calculation is input to the non-inverting input terminal (pin 5) of operational amplifier N2B through resistor R7. The triangular wave modulated carrier is input to the inverting input terminal (pin 6) of N2B through resistor R14. N2B performs pulse width modulation calculations to generate the PWM control signal. Matching the parameters of resistors R12 and R8 adjusts the amplitude level of the PWM control signal.

[0113] The amplification driving circuit includes an amplification driving chip V1, a diode V2, and resistors R26 and R28; wherein, the input terminal of the amplification driving chip V1 is connected to the modulation output terminal of the pulse modulation circuit; the output terminal of the amplification driving chip V1 is connected to the driving input terminal of the current sampling circuit; the output terminal of the amplification driving chip V1 is also connected to the negative terminal of the diode V2, and the positive terminal of the diode V2 is grounded.

[0114] The PWM control signal is input to the amplification and drive circuit to control the on / off state of the power semiconductor, thereby controlling the current of the proportional commutator valve. The PWM control signal is also input to the IN pin of the integrated power MOSFET device V1 to control its corresponding channel's OUT output. The OUT output is connected to the positive terminal of the proportional commutator valve coil via a Hall current sensor, and the power supply ground PGND is connected to the common terminal of the proportional valve electromagnet coil. Diode V2 provides a freewheeling path for the inductive load.

[0115] The sampling circuit includes an operational amplifier N2A, a Hall sensor D2, resistors R19, R20, R23, R24, and R25, and capacitors C7 and C8. For the operational amplifier N2A: the inverting input is connected to one end of resistor R24, one end of resistor R19, and one end of resistor R20; the other end of resistor R24 ​​is connected to QGND. The non-inverting input is connected to one end of resistor R25, and the output is connected to one end of resistor R23, the other end of resistor R19, and the other end of resistor R20. For the Hall sensor D2: the VIOUT terminal is connected to the other end of resistor R25 and one end of capacitor C8; the BW_SEL terminal, the GND terminal, and the other end of capacitor C8 are all connected to QGND; the GND terminal is also connected to one end of capacitor C7; the other end of capacitor C7 and the VCC terminal are both connected to the second DC power supply voltage. The two IP+ terminals are connected together as the drive input of the current sampling circuit; the two IP- terminals are connected together as the drive output of the current sampling circuit; the other end of resistor R23 is the feedback output of the current sampling circuit.

[0116] The current output from the amplification drive circuit to the proportional directional valve must flow through the Hall sensor D2 in the current sampling circuit. The Hall sensor D2 samples and converts the proportional directional valve current value into a voltage signal. This sampled voltage signal is input through resistor R25 to operational amplifier N2A. Proportional calculation is achieved through parameter matching of R19, R20, and R25, and the current value is fed back to the positive analog control circuit. In this embodiment, using a Hall sensor for proportional directional valve current sampling solves the problem that conventional analog proportional valve control drive circuits cannot be applied to proportional directional valves due to channel coupling interference.

[0117] During normal operation, whether controlling the proportional directional valve in either forward or reverse direction, the control method is simple, requiring only the transmission of control commands from the upper-level application controller. The circuit in this embodiment features digital bus control functionality, allowing it to act as an actuator receiving commands from the upper-level application controller, facilitating system networking. The circuit design is compact, enabling control of up to 16 channels of proportional directional valves (or 16 channels of proportional valves) within a standard 3U industrial board, effectively improving system integration and control capabilities.

[0118] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0119] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A proportional directional valve control and drive device based on forward and reverse rotation switching, characterized in that, The device includes: A forward / reverse switching circuit is used to determine the forward / reverse nature of the received analog given control signal. If it is forward, the analog feedback control circuit maintains its forward operating mode; if it is reverse, the analog feedback control circuit switches to a reverse operating mode. The forward / reverse switching circuit determines the forward / reverse nature of the received analog given control signal by: if the analog given control signal is less than a reference signal, then the analog given control signal is a forward analog given control signal; so that the analog feedback control circuit can directly process the forward analog given control signal to obtain a forward valve drive signal; if the analog given control signal is greater than the reference signal, then the analog given control signal is a reverse analog given control signal. The forward / reverse switching circuit also acquires the difference signal between the reverse analog given control signal and the reference signal; so that the analog feedback control circuit can process the difference signal to obtain a reverse valve drive signal. The analog feedback control circuit, when in forward operation mode, generates a first deviation control signal based on the analog given control signal and the current sampling signal obtained from the positive terminal of the proportional directional valve, and generates a forward valve drive signal for the proportional directional valve based on the first deviation control signal; when in reverse operation mode, it generates a second deviation control signal based on the analog given control signal and the current sampling signal obtained from the negative terminal of the proportional directional valve, and generates a reverse valve drive signal for the proportional directional valve based on the second deviation control signal.

2. The proportional directional valve control and drive device based on forward and reverse switching according to claim 1, characterized in that, The device also includes a digital-to-analog converter circuit. The analog given control signal is obtained by converting the corresponding digital given control signal into an analog-to-digital signal using the digital-to-analog converter circuit. The corresponding digital given control signal has the same positive and negative polarity as the analog given control signal.

3. The proportional directional valve control and drive device based on forward and reverse switching according to claim 2, characterized in that, The forward / reverse switching circuit includes: a differential amplifier N4, a comparator N5, a relay K, and resistors R46, R47, R48, and R49; wherein, The non-inverting input terminal of the comparator N5 is connected to one end of the normally open contact K-1 and one end of the normally closed contact K-2 of the relay, which is the given signal receiving terminal of the forward / reverse switching circuit and is used to receive the analog given control signal; the output terminal of the differential amplifier N4 is connected to the other end of the normally closed contact K-2, which is the given signal output terminal of the forward / reverse switching circuit. The comparator N5 is used to determine the positive or negative nature of the received analog given control signal: The inverting input of comparator N5 is connected to a reference voltage; the output is connected to the positive terminal of the control coil of relay K, and the negative terminal of relay K is grounded. The differential amplifier N4 is used to output the difference signal between the inverted analog given control signal and the reference signal: For differential amplifier N4: The non-inverting input terminal is connected to one end of resistor R48 and one end of resistor R49; the other end of resistor R48 is connected to the other end of normally open contact K-1 of relay K. The inverting input terminal is connected to one end of resistor R47 and one end of resistor R46; the other end of resistor R47 is grounded, and the other end of resistor R46 is connected to the reference voltage. The output of differential amplifier N4 is also connected to the other end of resistor R49; The normally open contact K-3 of the relay is connected between the output terminal of the analog feedback control circuit and the positive terminal of the proportional directional valve. The normally closed contact K-4 of the relay is connected between the output terminal of the analog feedback control circuit and the negative terminal of the proportional directional valve.

4. The proportional directional valve control and drive device based on forward and reverse switching according to claim 3, characterized in that, When in the forward operating mode, relay K does not operate, and normally closed contacts K-2 and K-4, normally open contacts K-1 and K-3 do not operate. When in the reverse operating mode, relay K is energized, normally closed contacts K-2 and K-4 are open, and normally open contacts K-1 and K-3 are closed.

5. The proportional directional valve control and drive device based on forward and reverse switching according to claim 3 or 4, characterized in that, The analog feedback control circuit consists of an analog control circuit, a pulse modulation circuit, an amplification and drive circuit, and a current sampling circuit based on a Hall sensor; wherein, The analog control circuit has a control input terminal connected to the given signal output terminal; a feedback terminal connected to the feedback output terminal of the current sampling circuit, used to receive the current sampling signal obtained from the positive terminal of the proportional directional valve when the analog feedback control circuit is in forward operation mode; and also used to receive the current sampling signal obtained from the negative terminal of the proportional directional valve when the analog feedback control circuit is in reverse operation mode; the output terminal is connected to the modulation input terminal of the pulse modulation circuit, used to output a first deviation control signal or a second deviation control signal; The pulse modulation circuit has its output terminal connected to the input terminal of the amplification drive circuit. The amplifier driver circuit has its output terminal connected to the driver input terminal of the current sampling circuit. The current sampling circuit has its drive output terminal connected to the positive terminal of the proportional directional valve via the normally closed contact K-4 of the relay, and also connected to the negative terminal of the proportional directional valve via the normally open contact K-3 of the relay. The common terminal of the proportional directional valve is grounded. The drive output terminal of the current sampling circuit is the output terminal of the analog feedback control circuit.

6. The proportional directional valve control and drive device based on forward and reverse switching according to claim 5, characterized in that, The analog control circuit includes operational amplifiers N1A and N1B, resistors R3, R5, R6, R10, R11, R15, R16, and R17, capacitors C3 and C4, and potentiometers RP1 and RP2; wherein, One end of resistor R16 is connected to QGND via capacitor C4; the other end of resistor R16 is connected to one end of resistor R15; the other end of resistor R15 is connected to one end of resistor R11 and one fixed end of potentiometer RP2; the other end of resistor R11 is connected to the sliding end of potentiometer RP2 and one end of resistor R17. For operational amplifier N1A: The inverting input is connected to one end of resistor R15, the non-inverting input is connected to QGND, and the output is connected to one end of resistor R17. For operational amplifier N1B: The inverting input terminal is connected to the other end of resistor R17, one end of resistor R10 and one end of capacitor C3. The other end of capacitor C3 is connected to the output terminal of operational amplifier N1B. The non-inverting input terminal is connected to QGND via resistor R3. The other end of resistor R10 is connected to one end of resistor R6 and the sliding end of potentiometer RP1. The other end of resistor R6 and one fixed end of potentiometer RP1 are both connected to -VEE. The other fixed end of potentiometer RP1 is connected to +VEE via resistor R5. One end of the resistor R16 is the control input terminal of the analog control circuit, the inverting input terminal of the operational amplifier N1B is the feedback terminal of the analog control circuit, and the output terminal of the operational amplifier N1B is the output terminal of the analog control circuit.

7. The proportional directional valve control and drive device based on forward and reverse switching according to claim 6, characterized in that, The pulse modulation circuit includes a pulse width modulation circuit and a triangular wave generator; wherein... The pulse width modulation circuit includes an operational amplifier N2B and resistors R7, R8, R12 and R14; For operational amplifier N2B: The non-inverting input is connected to one end of resistor R7, and the inverting input is connected to one end of resistor R14; the output is connected to +VEE via resistors R12 and R8 connected in series. The other end of resistor R7 is the modulation input terminal of the pulse modulation circuit; the end of resistor R12 connected to resistor R8 is the drive output terminal of the pulse modulation circuit; the other end of resistor R14 is the modulation output terminal of the pulse width modulation circuit. The triangular wave generator includes operational amplifiers N3A and N3B, and resistors R13, R18, R22 and R45; For operational amplifier N3A: The non-inverting input is connected to one end of resistor R13 and one end of resistor R45, the inverting input is connected to QGND, and the output is connected to the other end of resistor R13, one end of resistor R18, and one end of resistor R22. For operational amplifier N3B: The non-inverting input is connected to QGND, and the inverting input is connected to the other end of resistor R18, the other end of resistor R22, and one end of capacitor C6. The output of operational amplifier N3B is connected to the other end of capacitor C6 and the other end of R45. The output terminal of the operational amplifier N3B is the output terminal of the triangular wave generator, which is connected to the modulation output terminal of the pulse width modulation circuit.

8. The proportional directional valve control and drive device based on forward and reverse switching according to claim 7, characterized in that, The sampling circuit includes an operational amplifier N2A, a Hall sensor D2, resistors R19, R20, R23, R24, and R25, and capacitors C7 and C8; wherein, For operational amplifier N2A: The inverting input is connected to one end of resistor R24, one end of resistor R19, and one end of resistor R20, and the other end of resistor R24 ​​is connected to QGND; the non-inverting input is connected to one end of resistor R25, and the output is connected to one end of resistor R23, the other end of resistor R19, and the other end of resistor R20. For Hall sensor D2: The VIOUT terminal is connected to the other end of resistor R25 and one end of capacitor C8. The BW_SEL terminal, GND terminal, and the other end of capacitor C8 are all connected to QGND. The GND terminal is also connected to one end of capacitor C7. The other end of capacitor C7 and VCC terminal are both connected to the second DC power supply voltage. The two IP+ terminals are connected together as the drive input terminals of the current sampling circuit; the two IP- terminals are connected together as the drive output terminals of the current sampling circuit; the other end of resistor R23 is the feedback output terminal of the current sampling circuit.

9. The proportional directional valve control and drive device based on forward and reverse switching according to claim 8, characterized in that, The amplification drive circuit includes an amplification drive chip V1, a diode V2, and resistors R26 and R28; wherein, The input terminal of the amplifier driver chip V1 is connected to the modulation output terminal of the pulse modulation circuit; The output terminal of the amplifier driver chip V1 is connected to the drive input terminal of the current sampling circuit; The output of the amplifier driver chip V1 is also connected to the negative terminal of diode V2, and the positive terminal of diode V2 is grounded.

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