A Low-Cost Hydraulic Actuator Control System and Method

Abstract

The present invention discloses a low-cost hydraulic actuator control system and method, which comprises a power supply module, an input acquisition module, an MCU, an output drive module, and a communication module. The power supply module decouples and filters the input power supply and converts it into the voltage required for the normal operation of the MCU and external sensors. The communication module ensures that the hydraulic actuator control system communicates correctly with the host computer. The input acquisition module converts the input signals of different sensors into effective levels recognizable by the MCU. The MCU converts the collected effective levels into control signals of the hydraulic actuator according to a preset conversion method, and then transmits the control signals of the hydraulic actuator to the drive module. The drive module responds to the control signal output by the MCU and selects an open-loop or closed-loop circuit to drive the hydraulic actuator to operate. The most significant advantages of the present invention are strong anti-interference ability, reliable operation, and easy promotion and application. At the same time, it also meets the requirements of diversified sensor signals, continuous control and control accuracy.

Description

Technical Field

[0001] The present invention relates to a low-cost hydraulic actuator control system and method, which is applicable to the field of machinery. Background Art

[0002] With the continuous advancement of industrial automation, hydraulic control technology has become an indispensable key technology in industrial equipment. In recent years, sensor signals in the hydraulic industry have become increasingly diverse. Simultaneously, inappropriate sensor signal range selection and poor sensor-controller compatibility are common, posing significant challenges to input circuit compatibility. With the trend toward hydraulic-driven electronic control in the hydraulic industry, existing solenoid switch cartridge valve pilot control units have experienced issues such as impact and noise during switching. Proportional valve control systems, however, offer smoother and more controllable hydraulic operation while also requiring energy savings and noise reduction. Electro-hydraulic switch control cannot meet the requirements for continuous control and precision, while high-precision, fast-response electro-hydraulic servo control technology is complex and expensive. Summary of the Invention

[0003] The purpose of the present invention is to propose a low-cost hydraulic actuator control system and method, which includes a reusable input circuit to meet the diversity of current sensor signals. At the same time, it can perform open-loop control to ensure output stability and reduce costs, and can also collect output current through hardware and feed it back to the MCU for closed-loop control, thereby greatly improving the control accuracy and making the output independent of changes in the load valve block. It has reliable operation, strong anti-interference ability, and meets the requirements of continuous control and control accuracy.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a hydraulic actuator control system includes a power supply module, an input acquisition module, an MCU, a drive module, a communication module and a display module; the power supply module is used to decouple and filter the input power supply and convert it into the voltage required for the normal operation of the MCU and external sensors; the input acquisition module receives input signals from different types of sensors for controlling the hydraulic actuator, and converts the input signals into input levels recognizable by the MCU under the control of the MCU, and then transmits the input levels to the MCU; the MCU is used to collect the input levels, convert the input levels into control signals of the hydraulic actuator according to a preset conversion method, and then transmit the control signals of the hydraulic actuator to the drive module; the drive module is used to respond to the control signal output by the MCU and select an open-loop or closed-loop circuit to drive the hydraulic actuator to operate; the communication module is used to ensure that the hydraulic actuator control system communicates correctly with the host computer; the display module is connected to the MCU and is used to display status information of the hydraulic actuator control system;

[0005] The method comprises the following steps:

[0006] S1: The input acquisition module transmits the input signal from the sensor to the MCU. The MCU first controls the input acquisition module to select the input configuration of the input sensor according to the type of input signal. The input acquisition module then converts the input signal into an input level and transmits it to the MCU.

[0007] S2: The MCU continuously samples the input level for a preset number of times and performs pre-filtering calculations. If the continuously sampled input level exceeds the preset error range, the process proceeds to step S3; if the continuously sampled input level is within the preset error range, the process proceeds to step S4.

[0008] S3: The MCU marks the input level as a failure voltage, the MCU marks the output state as 0, and then returns to step S1;

[0009] S4: The MCU marks the input level as a valid voltage, and collects preset external factors and the working status of the execution component. If the external factors do not meet the preset conditions or the execution component is working abnormally, the MCU marks the output status as 0. At the same time, the MCU displays the external factors that do not meet the preset conditions or the execution component that is working abnormally on the display module to prompt the fault phenomenon; if all external conditions meet the preset conditions and the execution component is working normally, the MCU marks the output status as 1, and then enters step S5;

[0010] S5: The MCU detects the output state. If the output state is 0, the drive module is turned off and the hydraulic actuator does not move. If the output state is 1, the drive module is turned on and the process proceeds to step S6.

[0011] S6: The MCU collects the preset driving circuit information in the driving module. If it is an open-loop circuit drive, the process proceeds to step S7; if it is a closed-loop circuit drive, the process proceeds to step S8;

[0012] S7: The MCU uses an open-loop control method to control the drive module to drive the hydraulic actuator, and then returns to step S1;

[0013] S8: The MCU uses a closed-loop control method to control the drive module to drive the hydraulic actuator to operate, and then returns to step S1.

[0014] Furthermore, the aforementioned input acquisition module can provide input configurations for the input sensor including: 0-5V analog input, 0-36V analog input, pull-up input, pull-down input, floating input, GPIO input, and PWM input.

[0015] Furthermore, the aforementioned output current response MAP refers to a functional relationship between the effective voltage level and the output current. The abscissa of the output current response MAP is the effective voltage, and the ordinate is the control current.

[0016] Furthermore, the aforementioned open-loop control method is: when the input signal is at a valid level, the MCU transmits the corresponding control current to the drive module according to the output current response MAP; the principle is that the MCU outputs a PWM wave signal to the drive module, and the MCU calculates the corresponding duty cycle of the PWM wave output according to the size of the control current, and the drive module will amplify the waveform of the corresponding duty cycle output by the MCU into the required voltage of the hydraulic actuator; when the impedance of the hydraulic actuator remains unchanged, the drive module can output a stable drive current to drive the hydraulic actuator to operate; but when the impedance of the hydraulic actuator changes due to external factors, the drive current will change with the impedance change of the hydraulic actuator. If the impedance of the hydraulic actuator becomes larger, the drive current will become smaller, and vice versa, the impedance of the hydraulic actuator becomes smaller and the drive current becomes larger.

[0017] Furthermore, the aforementioned closed-loop control method is: when the input signal is a valid voltage, the MCU transmits the corresponding control current to the drive module according to the output current response MAP. The principle is that the MCU outputs a PWM wave signal to the drive module, and the MCU calculates the corresponding duty cycle of the PWM wave output according to the size of the control current; the drive module amplifies the waveform of the corresponding duty cycle output by the MCU into the required voltage of the hydraulic actuator; during the control process, the closed-loop circuit will collect the current driving current in real time, and convert it into voltage feedback to the MCU, and the MCU adjusts the PWM wave output duty cycle according to the feedback voltage, changes the voltage of the hydraulic actuator, and finally keeps the driving current output by the drive module the same as the control current; based on the above closed-loop control method, the driving current output by the drive module will not change with the change of the load, and the hydraulic actuator control system can continuously and stably control the action of the hydraulic actuator.

[0018] The low-cost hydraulic actuator control system and method described in the present invention, using the above technical solution, has the following technical effects compared with the prior art:

[0019] 1. Multifunctional input module design; can be configured with different ranges and meet the output requirements of different sensors;

[0020] 2. Open-loop and closed-loop control modes can be realized according to different load connection methods, which is adaptable to many occasions and has strong driving ability;

[0021] 3. The control system of this hydraulic actuator has fast response, high control accuracy and strong anti-interference ability, which not only meets the requirements of continuous control and control accuracy, but also meets the requirements of control cost;

[0022] 4. The input and output have built-in protection functions, which can protect the output execution components and controllers;

[0023] 5. Can cooperate with host computer for real-time calibration and monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a diagram of the control system of the hydraulic actuator;

[0025] Figure 2 This is a diagram of the input acquisition module configuration. DETAILED DESCRIPTION

[0026] In order to better understand the technical content of the present invention, specific embodiments are given and described below with reference to the accompanying drawings.

[0027] Various aspects of the present invention are described herein with reference to the accompanying drawings, which show a number of illustrative embodiments. The embodiments of the present invention are not limited to those described in the accompanying drawings. It should be understood that the present invention can be implemented by any of the various concepts and embodiments described above, as well as the concepts and implementations described in detail below, because the concepts and embodiments disclosed herein are not limited to any particular implementation. In addition, some aspects disclosed herein may be used alone or in any appropriate combination with other aspects disclosed herein.

[0028] Reference Figure 1 The present invention provides the following technical solutions: A hydraulic actuator control system includes a power module, an input acquisition module, an MCU, a drive module, a communication module and a display module; the power module is used to decouple and filter the input power and convert it into the voltage required for the normal operation of the MCU and external sensors; the input acquisition module receives input signals from different types of sensors for controlling the hydraulic actuator, and converts the input signals into input levels recognizable by the MCU under the control of the MCU, and then transmits the input levels to the MCU; the MCU is used to collect the input levels, convert the input levels into control signals of the hydraulic actuator according to a preset conversion method, and then transmit the control signals of the hydraulic actuator to the drive module; the drive module is used to respond to the control signal output by the MCU and select an open-loop or closed-loop circuit to drive the hydraulic actuator to operate; the communication module is used to ensure that the hydraulic actuator control system communicates correctly with the host computer; the display module is connected to the MCU and is used to display status information of the hydraulic actuator control system.

[0029] In this embodiment, the hydraulic actuator control method includes the following steps: the input acquisition module transmits the input signal from the sensor to the MCU, and the MCU first controls the input acquisition module to select the input configuration of the input sensor according to the type of the input signal. The input acquisition module can provide the input configuration for the input sensor including: 0-5V analog input, 0-36V analog input, pull-up input, pull-down input, floating input, GPIO input, and PWM input.

[0030] Reference Figure 2In this embodiment, the input acquisition module sends the input signal to the MCU for acquisition through voltage division; the 0-5V range and the 0-36V range use a selector, and the MCU controls the allocation of pins to select the range; at the same time, the MCU controls the selection of the pull-up configuration required by the input sensor, and then the input acquisition module converts the input signal into an input level and transmits it to the MCU.

[0031] The MCU continuously samples the input level for a preset number of times and performs pre-filtering calculations. If the continuously sampled input level exceeds the preset error range, the MCU marks the input level as an invalid voltage, marks the output state as 0, and then re-samples the input signal; if the continuously sampled input level is within the preset error value range, the MCU marks the input level as a valid voltage.

[0032] In this embodiment, to prevent malfunctions caused by electrical jitter in the input signal due to human factors or other factors, a pre-filter calculation is performed when confirming the input signal. The pre-filter calculation continuously samples the voltage N times. If the average of the N voltages is the same, then this voltage is the current effective voltage.

[0033] Then, the MCU collects the preset external factors and the working status of the execution components. If the external factors do not meet the preset conditions or the working status of the execution components is abnormal, the MCU will mark the output status as 0. At the same time, the MCU will display the external factors that do not meet the preset conditions or the execution components that are in abnormal working status through the display module to prompt the fault phenomenon; if all external conditions meet the preset conditions and the execution components are in normal working status, the MCU will mark the output status as 1.

[0034] In this embodiment, since the controller is integrated into the overall system, once input conditions are met, the control system simultaneously collects other data, such as temperature, oil pressure, and battery voltage. If these conditions are abnormal, control output may be disabled. Only when all conditions are met will the output be controlled according to the current MAP, driving the actuators normally.

[0035] Then, the MCU detects the output status. If the output status is 0, the drive module is turned off and the hydraulic actuator does not move; if the output status is 1, the drive module is turned on and the MCU collects the preset drive circuit information in the drive module.

[0036] In this embodiment, the drive module adopts a half-bridge drive. Different control programs are flashed according to the connection method (high side or low side) of different hydraulic actuators, and no distinction is made in the hardware. At the same time, the drive module can select open-loop or closed-loop control. When a short circuit or other fault occurs in the actuator, the control element can protect itself to avoid irreversible faults caused by the control unit.

[0037] In an open-loop circuit, the MCU uses an open-loop control method to control the driver module to drive the hydraulic actuator. The open-loop control method is as follows: when the input signal is at a valid level, the MCU transmits the corresponding control current to the driver module based on the output current response MAP. The principle is that the MCU outputs a PWM wave signal to the driver module. The MCU calculates the corresponding duty cycle of the PWM wave output based on the magnitude of the control current. The driver module amplifies the waveform with the corresponding duty cycle output by the MCU to the required voltage of the hydraulic actuator. When the impedance of the hydraulic actuator remains unchanged, the driver module can output a stable drive current to drive the hydraulic actuator. However, when the impedance of the hydraulic actuator changes due to external factors, the drive current will change with the change in the hydraulic actuator impedance. If the hydraulic actuator impedance increases, the drive current will decrease. Conversely, if the hydraulic actuator impedance decreases, the drive current will increase.

[0038] In a closed-loop circuit, the MCU uses a closed-loop control method to control the driver module's operation of the hydraulic actuator. This closed-loop control method is as follows: when the input signal is a valid voltage, the MCU transmits the corresponding control current to the driver module based on the output current response MAP. The principle is that the MCU outputs a PWM wave signal to the driver module. The MCU calculates the corresponding duty cycle of the PWM wave output based on the magnitude of the control current. The driver module then amplifies the waveform with the corresponding duty cycle output by the MCU to the required voltage of the hydraulic actuator. During the control process, the closed-loop circuit collects the current driving current in real time, converts it into a voltage, and feeds it back to the MCU. The MCU adjusts the PWM wave output duty cycle based on the feedback voltage, changing the voltage of the hydraulic actuator, ultimately maintaining the driving current output by the driver module at the same level as the control current. Based on this closed-loop control method, the driving current output by the driver module does not change with changes in load, and the hydraulic actuator control system can continuously and stably control the operation of the hydraulic actuator.

[0039] In this embodiment, the output current response MAP refers to the functional relationship between the effective level and the output current. The abscissa of the output current response MAP is the effective level, and the ordinate is the control current. The specific functional relationship needs to be preset.

[0040] While the present invention has been described above with reference to preferred embodiments, this is not intended to limit the present invention. Persons skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A low-cost hydraulic actuator control method for achieving precise control of the response of the hydraulic actuator to complete the corresponding action, characterized in that: The control system of the hydraulic actuator includes a power module, an input acquisition module, an MCU, a drive module, a communication module and a display module; The power module is used to decouple and filter the input power and convert the input power into the voltage required for the normal operation of the MCU and external sensors; The input acquisition module receives input signals from different types of sensors for controlling hydraulic actuators, converts the input signals into input levels recognizable by the MCU under the control of the MCU, and then transmits the input levels to the MCU; The MCU is used to collect input levels, convert the input levels into control signals for hydraulic actuators, and then transmit the control signals for hydraulic actuators to the drive module; The driver module is used to respond to the control signal output by the MCU and select open-loop or closed-loop circuit to drive the hydraulic actuator action; The communication module is used to ensure that the hydraulic actuator control system communicates correctly with the host computer; The display module is connected to the MCU and is used to display the status information of the hydraulic actuator control system; The method comprises the following steps: S1: The input acquisition module transmits the input signal from the sensor to the MCU. The MCU first controls the input acquisition module to select the input configuration of the input sensor according to the type of input signal. The input acquisition module then converts the input signal into an input level and transmits it to the MCU. S2: The MCU continuously samples the input level for a preset number of times and performs pre-filtering calculations. If the continuously sampled input level exceeds the preset error range, the process proceeds to step S3; if the continuously sampled input level is within the preset error range, the process proceeds to step S4. S3: The MCU marks the input level as a failure voltage, the MCU marks the output state as 0, and then returns to step S1; S4: The MCU marks the input level as a valid voltage, and collects preset external factors and the working status of the execution component. If the external factors do not meet the preset conditions or the execution component is working abnormally, the MCU marks the output status as 0. At the same time, the MCU displays the external factors that do not meet the preset conditions or the execution component that is working abnormally on the display module to prompt the fault phenomenon; if all external conditions meet the preset conditions and the execution component is working normally, the MCU marks the output status as 1, and then enters step S5; S5: The MCU detects the output state. If the output state is 0, the drive module is turned off and the hydraulic actuator does not move. If the output state is 1, the drive module is turned on and the process proceeds to step S6. S6: The MCU collects the preset driving circuit information in the driving module. If it is an open-loop circuit drive, the process proceeds to step S7; if it is a closed-loop circuit drive, the process proceeds to step S8; S7: The MCU uses an open-loop control method to control the drive module to drive the hydraulic actuator, and then returns to step S1; S8: The MCU uses a closed-loop control method to control the drive module to drive the hydraulic actuator to operate, and then returns to step S1.

2. A low-cost hydraulic actuator control method according to claim 1, characterized in that: The input configurations provided by the input acquisition module for the input sensor include: 0-5V analog input, 0-36V analog input, pull-up input, pull-down input, floating input, GPIO input, and PWM input.

3. A low-cost hydraulic actuator control method according to claim 1, characterized in that: The output current response MAP refers to the functional relationship between the effective level and the output current. The abscissa of the output current response MAP is the effective voltage, and the ordinate is the control current.

4. A low-cost hydraulic actuator control method according to claim 1, characterized in that: The open-loop control method is as follows: when the input signal is at a valid level, the MCU transmits the corresponding control current to the drive module according to the output current response MAP; the principle of the open-loop control method is that the MCU outputs a PWM wave signal to the drive module, and the MCU calculates the corresponding duty cycle of the PWM wave output according to the size of the control current. The drive module will amplify the waveform of the corresponding duty cycle output by the MCU into the required voltage of the hydraulic actuator. When the impedance of the hydraulic actuator remains unchanged, the drive module can output a stable drive current to drive the hydraulic actuator to operate; but when the impedance of the hydraulic actuator changes due to external factors, the drive current will change with the impedance change of the hydraulic actuator. If the impedance of the hydraulic actuator increases, the drive current will decrease. Conversely, when the impedance of the hydraulic actuator decreases, the drive current increases.

5. The low-cost hydraulic actuator control method according to claim 1, characterized in that: The closed-loop control method is as follows: when the input signal is a valid voltage, the MCU transmits the corresponding control current to the drive module according to the output current response MAP. The principle of the closed-loop control method is that the MCU outputs a PWM wave signal to the drive module, and the MCU calculates the corresponding duty cycle of the PWM wave output according to the size of the control current; the drive module amplifies the waveform of the corresponding duty cycle output by the MCU into the required voltage of the hydraulic actuator; during the control process, the closed-loop circuit will collect the current driving current in real time, and convert it into voltage feedback to the MCU, and the MCU adjusts the PWM wave output duty cycle according to the feedback voltage, changes the voltage of the hydraulic actuator, and finally keeps the driving current output by the drive module the same as the control current; based on the above closed-loop control method, the driving current output by the drive module will not change with the change of the load, and the hydraulic actuator control system can continuously and stably control the action of the hydraulic actuator.

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