Integrated linear hydraulic actuator absolute displacement detection system and method

Abstract

The invention provides an absolute displacement detection system and method for an integrated linear hydraulic actuator. The detection system comprises a control valve, an actuating cylinder, an integrated actuating shaft, a transmitting electrode plate, a signal processing system, a system controller and a driving connector. Wherein the control valve and the actuating cylinder are communicated through a machine and an oil way; the actuating cylinder and the integrated actuating shaft are in sealed sliding, and the actuating cylinder can slide according to an instruction of the control valve so as to drive the actuating shaft driving joint to move; the transmitting electrode plate is in clearance fit with the integrated actuating shaft to generate capacitance reflection; the transmitting electrode plate and the integrated actuating shaft are connected with the signal processing system through cables, and collected signals are processed to obtain displacement feedback values. When the emission electrode and the integrated actuating shaft generate relative displacement, each Ci corresponds to a fixed position, and absolute displacement can be measured after initial calibration; wherein Ci is the total capacitance of the emission electrode and the integrated actuating shaft.

Description

Technical Field

[0001] The present application belongs to the field of aviation pneumatic and hydraulic actuation technology, and specifically relates to an integrated linear hydraulic actuator absolute displacement detection system and method. Background Art

[0002] Hydraulic actuators are widely used in the aviation field due to their advantages such as large output force and stable load. They are mainly used in flight control surface control, landing gear deployment and retraction, engine throttle and nozzle direction control.

[0003] At present, LVDT sensors are usually used for additional sensing functions of aviation hydraulic actuators, which are generally placed on the inner and outer sides of the actuator cylinder in parallel. This form will increase the structure and spatial dimensions, as well as the difficulty of structural strength and stiffness design, resulting in an increase in product weight and spatial volume, and reduced product reliability. Summary of the invention

[0004] Purpose of the invention: High integration of sensing and actuation is an inevitable development of hydraulic actuator sensing technology. The application of low-cost and small-volume capacitive sensing technology in the field of hydraulic actuation has gradually attracted research attention; therefore, this application proposes an integrated linear hydraulic actuator absolute displacement detection system and method.

[0005] In a first aspect, the present application provides an integrated linear hydraulic actuator absolute displacement detection system, the detection system comprising a control valve, an actuator cylinder, an integrated actuator shaft, a transmitting electrode plate, a signal processing system, a system controller and a drive joint;

[0006] Among them, the control valve and the actuator cylinder are connected mechanically and through oil circuits; the actuator cylinder and the integrated actuator shaft are sealed and slidable according to the control valve command to drive the actuator shaft drive joint to move; the transmitting electrode plate and the integrated actuator shaft are clearance-matched to generate capacitance response; the transmitting electrode plate and the integrated actuator shaft are connected to the signal processing system respectively by cables, and the collected signals are processed to obtain displacement feedback values; when the transmitting electrode and the integrated actuator shaft undergo relative displacement, each Ci corresponds to a fixed position, and after initial calibration, the absolute displacement can be measured; wherein Ci is the total capacitance of the transmitting electrode and the integrated actuator shaft.

[0007] Preferably, capacitive coupling is formed between the integrated actuating shaft and the emitting electrode plate.

[0008] Preferably, the capacitance formed by the electrodes of the integrated actuating shaft with equal spacing and increasing depth and the transmitting electrode plate is arithmetically distributed. After initial calibration, the capacitance signal at any position can be obtained. After demodulation by the signal processing system, the displacement signal is transmitted to the system controller, and the system controller sends instructions to the control valve to realize absolute displacement monitoring and closed-loop drive control of the hydraulic product drive.

[0009] Preferably, the transmitting electrode plate and the signal processing system are integrated into a feedback system, and the feedback system is connected to the actuating cylinder by bolts to integrate the feedback system with the actuating cylinder.

[0010] Preferably, the signal processing system is connected to the product system controller by a cable, and the displacement of the driven product is fed back to the system controller; the system controller is connected to the control valve by a cable, and the system control command is sent to the control valve, forming a closed-loop controlled linear drive system.

[0011] In a second aspect, the present application also provides an integrated linear hydraulic actuator absolute displacement detection method, the method comprising:

[0012] Step 1, preparing an actuator shaft substrate with concave-convex intervals and grooves increasing sequentially along the actuator stroke direction;

[0013] Step 2, spraying ceramic on the surface of the actuator shaft substrate to form a reflective plate;

[0014] Step 3, grinding the surface of the ceramic sprayed actuator shaft to meet the requirements of sliding sealing;

[0015] Step 4: The ground actuating shaft is sealed to reduce the surface penetration of the surface in contact with the aviation oil source, thereby forming an integrated actuating shaft with both execution and sensing functions;

[0016] Step 5, prepare an insulating structure with the actuator structure, which is also a concave-convex spacing structure, and the width of the groove is the same as that of the actuator shaft base;

[0017] Step 6: Install a copper sheet in the groove and lead out a wire from the copper sheet to form an emitter;

[0018] Step 7: prepare a demodulation device, filter and convert the periodic capacitance signal with amplitude variation formed between the emitter and the integrated actuating shaft, and make signal demodulation hardware;

[0019] Step 8: prepare a protective housing for the demodulation device, install the signal demodulation device inside the protective housing, and connect the emitter lead to the signal demodulation device to form a feedback system with transmitting electrical signals and demodulating signals;

[0020] Step 9: Assemble the integrated actuating shaft into the interior of the actuating cylinder through the sealing assembly;

[0021] Step 10, install the feedback system to the end of the cylinder through bolts;

[0022] Step 11, encapsulate the demodulated signal and the digital display part in the test system;

[0023] Step 12: The feedback system lead wire is externally connected to the test system host, and the displacement monitoring and feedback of the actuator axis are realized through the system test software.

[0024] Preferably, the width of the protrusion is 1 / 2 of the width of the groove.

[0025] Preferably, the method further comprises:

[0026] When the transmitting electrode and the integrated actuating shaft are relatively displaced, each C i Corresponding to a fixed position, after initial calibration, the absolute displacement can be measured; where C i It is the total capacitance of the transmitting electrode and the integrated actuator shaft.

[0027] This application has the following technical effects:

[0028] The present invention is a linear actuator displacement detection system with integrated actuation and sensing, wherein the integrated actuation axis has both actuation and displacement sensing functions, and the absolute displacement monitoring and closed-loop drive control of the actuator are realized through system control connection.

[0029] The present invention adopts an integrated actuating shaft to carry out variable pole pitch design and capacitance gate signal acquisition and calibration to realize absolute displacement monitoring, real-time feedback of the working state of the actuator, achieve high integration of sensors, and improve the working reliability of the actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a diagram of the device structure provided in the embodiment of the present application;

[0031] Figure 2 It is a structural composition diagram provided by an embodiment of the present application;

[0032] Figure 3 is a schematic diagram of an integrated actuating shaft base provided in an embodiment of the present application;

[0033] Figure 4 is a structural diagram of a feedback system provided in an embodiment of the present application;

[0034] Figure 5 It is a schematic diagram of the actuation structure based on capacitor-gate integration provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] See also Figure 1-Figure 5 The present invention provides an integrated linear actuator absolute displacement detection system, which is composed of a control valve 1, an actuator cylinder 2, an integrated actuator shaft 3, a transmitting electrode plate 4, a signal processing system 5, a system controller 6 and a drive connector 7, wherein the transmitting electrode plate 4 and the signal processing system 5 form a feedback system 8, see Figure 1 .

[0036] The connection relationship and signal transmission between the components of the present invention are as follows:

[0037] The control valve 1 and the actuating cylinder 2 are connected by mechanical and oil circuits; the actuating cylinder 2 and the integrated actuating shaft 3 are sealed and slidable, and can slide according to the control valve 1 command to drive the actuating shaft 3 to drive the joint 7 to move; the transmitting electrode plate 4 and the integrated actuating shaft 3 are clearance-matched to generate capacitance response; the transmitting electrode plate 4 and the integrated actuating shaft 3 are connected to the signal processing system 5 by cables, and the collected signals are processed to obtain the displacement feedback value; the transmitting electrode plate 4 and the signal processing system 5 are integrated into a feedback system 8, and the feedback system 8 and the actuating cylinder 2 are connected by bolts, and the feedback system 7 is integrated with the actuating cylinder 2; the signal processing system 5 and the product system controller 6 are connected by cables, and the displacement of the driven product is fed back to the system controller 6; the system controller 6 and the control valve 1 are connected by cables, and the system control command is sent to the control valve. A closed-loop controlled linear drive system is formed.

[0038] Capacitive coupling is formed between the integrated actuating shaft 3 and the transmitting electrode plate 4. The capacitance formed by the electrodes of the integrated actuating shaft 3 with increasing depth at equal intervals and the transmitting electrode plate 4 is equidistantly distributed. After initial calibration, a capacitance signal at any position can be obtained. After demodulation by the signal processing system 5, the displacement signal is transmitted to the system controller 6, and a command is sent to the control valve 1 through the system controller 6 to realize absolute displacement monitoring and closed-loop drive control of hydraulic product drive.

[0039] The present invention is a linear actuator displacement detection system with integrated actuation and sensing, wherein the integrated actuation shaft has both actuation and displacement sensing functions, and realizes absolute displacement monitoring and closed-loop drive control of the actuator through system control connection; the present invention adopts the integrated actuation shaft to carry out variable pole pitch design and capacitive gate signal acquisition and calibration to realize absolute displacement monitoring, real-time feedback of the working state of the actuator, realize high integration of sensors, and improve the working reliability of the actuator.

[0040] The present invention is used for a real-time displacement detection system for a linear actuator. It adopts a design of evenly spaced and progressively increasing depth grooves of an integrated actuating shaft, realizes a variable pole pitch design of an integrated actuating shaft and a transmitting electrode plate, performs absolute displacement measurement of the actuator through initial calibration of a capacitive gate signal, forms a highly integrated absolute displacement detection system for a linear actuator, and realizes closed-loop drive control.

[0041] The present invention will be further described below in conjunction with specific embodiments.

[0042] In one embodiment, an integrated hydraulic actuator absolute displacement detection system is used, which is composed of a control valve 1, an actuator cylinder 2, an integrated actuator shaft 3, a transmitting electrode plate 4, a signal processing system 5 and a system controller 6. The transmitting electrode plate 4 and the signal processing system 5 form a feedback system 7. Figure 1 .

[0043] The connection relationship and signal transmission between the components of the present invention are as follows:

[0044] The control valve 1 and the actuating cylinder 2 are connected by mechanical and oil circuits; the actuating cylinder 2 and the integrated actuating shaft 3 are sealed and slidable, and can slide and drive according to the control valve 1 command; the transmitting electrode plate 4 and the integrated actuating shaft 3 are clearance-matched, generating capacitance response; the transmitting electrode plate 4 and the integrated actuating shaft 3 are connected to the signal processing system 5 by cables, and the collected signals are processed to obtain the displacement feedback value; the transmitting electrode plate 4 and the signal processing system 5 are integrated into a feedback system 7, and the feedback system 7 and the actuating cylinder 2 are connected by bolts, and the feedback system 7 and the actuating cylinder 2 are integrated; the signal processing system 5 and the product system controller 6 are connected by cables, and the displacement of the driven product is fed back to the system controller 6; the product system controller 6 and the control valve 1 are connected by cables, and the system control command is sent to the control valve. A closed-loop controlled linear drive system is formed.

[0045] In other embodiments of the present application, an integrated linear actuator absolute displacement detection system structure is as follows: Figure 2 .

[0046] The actuator shaft adopts a conductive metal structure, and grooves with a width of 2.5mm and a spacing of W are processed on its surface. The depth of the grooves hi increases by 0.1mm. The integrated actuator shaft base is as follows Figure 3 The surface is ceramic coated, and the ceramic coating fills the inside of the groove. The overall surface coating is 0.2mm. At the same time, the two transmitting electrode plates in the feedback system are metal rings, such as Figure 4 As shown, the metal ring and the integrated actuating shaft are made of the same conductive material, with a width of W, an assembly spacing of 1.5W, and a housing made of insulating material, in which a signal processing system is embedded.

[0047] Capacitive coupling is formed between the metal ring and the integrated actuating shaft. The capacitance formed by the transmitting electrode and the integrated actuating shaft includes two parts. When the transmitting electrode overlaps the integrated moving protrusion position x, the transmitting electrode and the groove form a capacitance C 1i , the emitting electrode and the raised position form a capacitor C2. The total capacitance is C i =C 1i +C2.

[0048]

[0049] in,

[0050] ε0 is the dielectric constant of air between the plates;

[0051] ε r is the dielectric constant of the medium between the plates;

[0052] R is the protruding radius of the integrated actuating shaft;

[0053] x is the overlapping length between the emitting electrode and the integrated moving protrusion position;

[0054] d is the distance between the transmitting electrode and the integrated actuating shaft;

[0055] h i It is the depth of the groove of the integrated actuating shaft;

[0056] w is the width of the groove and protrusion of the integrated actuating shaft;

[0057] C 1i A capacitor is formed between the transmitting electrode and the integrated actuating shaft groove;

[0058] C2 is the capacitance formed by the emitting electrode and the protruding position;

[0059] C i It is the total capacitance of the transmitting electrode and the integrated actuator shaft.

[0060] When the transmitting electrode and the integrated actuating shaft are relatively displaced, each C i Corresponding to a fixed position, after initial calibration, the absolute displacement can be measured.

[0061] The process of integrated linear hydraulic actuator preparation and absolute displacement detection method is as follows:

[0062] Step 1, preparing an actuator shaft substrate with concave-convex intervals and grooves increasing sequentially along the actuator stroke direction;

[0063] Step 2, spraying ceramic on the surface of the actuator shaft substrate to form a reflective plate;

[0064] Step 3, grinding the surface of the ceramic sprayed actuator shaft to meet the requirements of sliding sealing;

[0065] Step 4: The ground actuating shaft is sealed to reduce the surface penetration of the surface in contact with the aviation oil source, thereby forming an integrated actuating shaft with both execution and sensing functions;

[0066] Step 5, prepare an insulating structure with the actuator structure, which is also a concave-convex spacing structure, the width of the concave part is the same as the actuating shaft base, and the width of the convex part is 1 / 2 of the width of the concave part;

[0067] Step 6: Install a copper sheet in the groove and lead out a wire from the copper sheet to form an emitter;

[0068] Step 7: prepare a demodulation device, filter and convert the periodic capacitance signal with amplitude variation formed between the emitter and the integrated actuating shaft, and make signal demodulation hardware;

[0069] Step 8: prepare a protective housing for the demodulation device, install the signal demodulation device inside the protective housing, and connect the emitter lead to the signal demodulation device to form a feedback system with transmitting electrical signals and demodulating signals;

[0070] Step 9: Assemble the integrated actuating shaft into the interior of the actuating cylinder through the sealing assembly;

[0071] Step 10, install the feedback system to the end of the cylinder through bolts;

[0072] Step 11, encapsulate the demodulated signal and the digital display part in the test system;

[0073] Step 12: The feedback system lead wire is externally connected to the test system host, and the displacement monitoring and feedback of the actuator axis are realized through the system test software.

Claims

1. An integrated linear hydraulic actuator absolute displacement detection system, characterized in that: The detection system comprises a control valve, an actuator cylinder, an integrated actuator shaft, a transmitting electrode plate, a signal processing system, a system controller and a drive joint; Among them, the control valve and the actuator cylinder are connected mechanically and through oil circuits; the actuator cylinder and the integrated actuator shaft are sealed and slidable according to the control valve command to drive the actuator shaft drive joint to move; the transmitting electrode plate and the integrated actuator shaft are clearance-matched to generate capacitance response; the transmitting electrode plate and the integrated actuator shaft are connected to the signal processing system respectively by cables, and the collected signals are processed to obtain the displacement feedback value; when the transmitting electrode and the integrated actuator shaft undergo relative displacement, each Ci corresponds to a fixed position, and after initial calibration, the absolute displacement can be measured; wherein Ci is the total capacitance of the transmitting electrode and the integrated actuator shaft.

2. The detection system according to claim 1, characterized in that: Capacitive coupling is formed between the integrated actuating shaft and the transmitting electrode plate.

3. The detection system according to claim 2, characterized in that: The capacitance formed by the electrodes with equal spacing and increasing depth of the integrated actuating shaft and the transmitting electrode plate is equidistantly distributed. After initial calibration, the capacitance signal at any position can be obtained. After demodulation by the signal processing system, the displacement signal is transmitted to the system controller, and the system controller sends instructions to the control valve to realize absolute displacement monitoring and closed-loop drive control of hydraulic product drives.

4. The detection system according to claim 1, characterized in that: The transmitting electrode plate and the signal processing system are integrated into a feedback system, and the feedback system and the actuating cylinder are connected by bolts to integrate the feedback system and the actuating cylinder.

5. The detection system according to claim 1, characterized in that: The signal processing system is connected to the product system controller by cables, and the displacement of the driven product is fed back to the system controller; the system controller is connected to the control valve by cables, and the system control instructions are sent to the control valve, forming a closed-loop controlled linear drive system.

6. An integrated linear hydraulic actuator absolute displacement detection method, characterized in that: The method comprises: Step 1, preparing an actuator shaft substrate with concave-convex intervals and grooves increasing sequentially along the actuator stroke direction; Step 2, spraying ceramic on the surface of the actuator shaft substrate to form a reflective plate; Step 3, grinding the surface of the ceramic sprayed actuator shaft to meet the requirements of sliding sealing; Step 4: The ground actuating shaft is sealed to reduce the surface penetration of the surface in contact with the aviation oil source, thereby forming an integrated actuating shaft with both execution and sensing functions; Step 5, prepare an insulating structure with the actuator structure, which is also a concave-convex spacing structure, and the width of the groove is the same as that of the actuator shaft base; Step 6: Install a copper sheet in the groove and lead out a wire from the copper sheet to form an emitter; Step 7: prepare a demodulation device, filter and convert the periodic capacitance signal with amplitude variation formed between the emitter and the integrated actuating shaft, and make signal demodulation hardware; Step 8: prepare a protective housing for the demodulation device, install the signal demodulation device inside the protective housing, and connect the emitter lead to the signal demodulation device to form a feedback system with transmitting electrical signals and demodulating signals; Step 9: Assemble the integrated actuating shaft into the interior of the actuating cylinder through the sealing assembly; Step 10, install the feedback system to the end of the cylinder through bolts; Step 11, encapsulate the demodulated signal and the digital display part in the test system; Step 12: The feedback system lead wire is externally connected to the test system host, and the displacement monitoring and feedback of the actuator axis are realized through the system test software.

7. The method according to claim 6, characterized in that The width of the protrusion is 1 / 2 of the width of the groove.

8. The method according to claim 6, characterized in that The method further comprises: When the transmitting electrode and the integrated actuating shaft are relatively displaced, each C i Corresponding to a fixed position, after initial calibration, the absolute displacement can be measured; where C i It is the total capacitance of the transmitting electrode and the integrated actuator shaft.

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