Electromechanical actuator initial position zero searching and error compensation device and method

Abstract

An electromechanical actuator initial position zero searching and error compensation device and method relate to the field of electromechanical actuators and comprise a cross-shaped support lug, one end of the cross-shaped support lug facing an actuator shell is provided with a mounting groove, an input shaft and an output shaft are rotatably connected to the cross-shaped support lug, and a cover plate is located in the mounting groove and fixedly connected with the cross-shaped support lug. A stator of the first rotary transformer is fixedly connected to the cover plate, and the output shaft penetrates through a rotor of the first rotary transformer and is used for driving the rotor of the first rotary transformer to rotate together; a stator of the second rotary transformer is fixedly connected to the actuator shell, the actuator shell is rotationally connected with the motor shaft, one end of the second rotary transformer is connected with the motor shaft, the other end of the second rotary transformer is connected with the input shaft, and the input shaft drives the output shaft to rotate through the transmission assembly. The number of turns, deviating from the zero position of the actuator, of the servo motor is measured through the angle difference value of the two rotary transformers, so that the mechanical zero position of the actuator is indirectly measured, and the zero searching function of the actuator is achieved.

Description

Technical Field

[0001] The invention relates to a position zero-finding resolver installation structure at the tail of an electromechanical actuator, belonging to the technical field of electromechanical actuators. Background Art

[0002] Electromechanical actuators control the movement of loads directly or indirectly by controlling the operation of motors to achieve target position control, and play a very critical role in the flight control process of launch vehicles. In order to ensure the precise control of load position by electromechanical actuators, it is necessary to accurately locate the mechanical initial zero position of the actuator to reduce the error. As launch vehicles continue to develop in the direction of lightweight and miniaturized design, lightweighting the initial position zeroing structure of electromechanical actuators, integration, and reliability improvement have important application prospects and significance.

[0003] Chinese patent CN110336410A is named as a novel integrated linear displacement output electromechanical actuator. In the invented device, the motor, linear displacement sensor and lead screw assembly of the electromechanical actuator share an actuator housing, which simplifies the actuator structure and enhances the overall reliability of the actuator. However, a linear displacement sensor is still used for initial position zeroing. The linear displacement sensor is installed on the actuator housing, which requires separate design of wiring holes and short cables, resulting in a relatively complex structure.

[0004] The Chinese patent CN118912175A is named as a tooth difference counting structure for an integrated electromechanical actuator. In this invention, the gear reducer and the dual rotary transformer replace the linear displacement sensor structure and are installed on the rear end cover of the motor. The electromechanical servo actuator is integrated in a limited space. Although this solution eliminates the steps of designing wiring holes and short cables, the motor is driven by a gear reducer, which has the problem of a large number of single machines and low reliability of initial position zeroing. Summary of the invention

[0005] The technical problem solved by the present application is: to overcome the deficiencies of the prior art and provide an initial position zeroing and error compensation device for an electromechanical actuator, which uses the angular difference between two resolvers to measure the number of turns of the servo motor deviating from the actuator zero position, thereby indirectly measuring the mechanical zero position of the actuator, thereby realizing the zeroing function of the actuator.

[0006] The technical solutions provided by this application are as follows:

[0007] A device for finding zero and compensating an initial position of an electromechanical actuator, comprising a cross lug, an inner cover plate of the cross lug, a first rotary transformer, a second rotary transformer, an input shaft, an output shaft and a transmission assembly; the cross lug is connected to one end of an actuator housing, a mounting groove is provided at one end of the cross lug facing the actuator housing, one end of the input shaft and one end of the output shaft are both rotatably connected to the cross lug, the inner cover plate of the cross lug is located in the mounting groove and is fixedly connected to the cross lug, and the input shaft and the output shaft both pass through the inner cover plate of the cross lug; the stator of the first rotary transformer is fixedly connected to the side of the inner cover plate of the cross lug away from the first mounting convex ring, the output shaft passes through the rotor of the first rotary transformer and is used to drive the rotor of the first rotary transformer to rotate together; the stator of the second rotary transformer is fixedly connected to the actuator housing, a motor shaft is rotatably connected in the actuator housing, one end of the second rotary transformer is connected to the motor shaft and the other end is connected to the input shaft, so that the motor shaft drives the input shaft to rotate; the transmission assembly is connected between the input shaft and the output shaft, so that the input shaft drives the output shaft to rotate through the transmission assembly.

[0008] The transmission assembly comprises an input gear and an output gear, wherein the input gear is connected to the input shaft and rotates together with the input shaft, and the output gear is connected to the output shaft and rotates together with the output shaft, and the input gear and the output gear are meshed.

[0009] The cross support ear is provided with a first mounting convex ring and a second mounting convex ring at the bottom of the mounting groove, one end of the input shaft is rotatably connected in the first mounting convex ring, and one end of the output shaft is rotatably connected in the second mounting convex ring.

[0010] The input shaft is rotatably connected to the inner wall of the first mounting convex ring via an input bearing, and the output shaft is rotatably connected to the inner wall of the second mounting convex ring via an output bearing.

[0011] An input shaft retaining ring is installed at the end of the circumferential surface of the input shaft, a first limiting convex ring is provided on the circumferential surface of the input shaft, and the input bearing is located between the input shaft retaining ring and the first limiting convex ring;

[0012] An output shaft retaining ring is installed at the end of the output shaft circumferential surface, a second limiting convex ring is arranged on the output shaft circumferential surface, and the output bearing is located between the second limiting convex ring and the output shaft retaining ring.

[0013] A retaining ring for the input hole is installed at the end of the first mounting protrusion ring, and a retaining ring for the output hole is installed at the end of the second mounting protrusion ring. The retaining ring for the input hole is located on the side of the input bearing facing the inner cover plate of the cross lug, and the retaining ring for the output hole is located on the side of the output bearing facing the inner cover plate of the cross lug.

[0014] The input bearing and the output bearing are both provided in pairs.

[0015] A method for initial position zeroing and error compensation of an electromechanical actuator, using any of the above-mentioned devices for initial position zeroing and error compensation of an electromechanical actuator for compensation, comprising:

[0016] The initial installation state of the motor shaft is zero position, and the zero position states of the first rotary transformer and the second rotary transformer when the motor shaft is zero position are recorded, and the rotor angles of the first rotary transformer and the second rotary transformer in the zero position state are defined as;

[0017] After the actuator is used, the motor shaft position when the actuator is turned off is at zero position or not at zero position; before using the actuator after being used, first start the first rotary transformer and the second rotary transformer, and record the starting state of the rotors of the first rotary transformer and the second rotary transformer according to the first rotary transformer and the second rotary transformer, and calculate the angle difference between the rotors of the first rotary transformer and the second rotary transformer according to the starting state;

[0018] Obtaining the position of the motor shaft in a startup state according to the angle difference between the rotors of the first rotary transformer and the second rotary transformer;

[0019] Control the motor shaft to return to zero position from the position at startup.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] (1) The present invention adopts a tooth-difference dual-resolver structure to measure the number of turns of the servo motor deviating from the actuator zero position, thereby indirectly measuring the mechanical zero position of the actuator, which significantly improves the reliability of the actuator's homing function.

[0022] (2) The present invention adopts an integrated design, combining a dual rotary variable structure with an actuator lug. Compared with the traditional linear displacement sensor structure, the present invention integrates the transmission and power components without changing the original actuator lug size and ensuring the transmission efficiency and structural strength, thereby reducing the number of single units in the steering gear system, improving the utilization efficiency of the space at the tail of the steering gear, reducing the total axial length of the electromechanical actuator, reducing the weight of the steering gear, and increasing the stability of the structure and function realization. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the installation structure of the dual rotary transformer tail in an embodiment of the present invention;

[0024] Figure 2 It is a cross-sectional view of the dual rotary transformer installation structure in an embodiment of the present invention;

[0025] Figure 3 Schematic diagram of the inner cover plate of the cross lug in an embodiment of the present invention;

[0026] Figure 4 A schematic diagram of the integrated cross lug structure in an embodiment of the present invention;

[0027] Figure 5 It is a partial cross-sectional view of an integrated cross lug installed on an actuator housing in an embodiment of the present invention;

[0028] Figure 6 It is a three-dimensional assembly diagram of an integrated cross lug installed on an actuator housing in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] The present application embodiment discloses an initial position zeroing and error compensation device for an electromechanical actuator, such as Figures 1-2 As shown, the position zeroing resolver installation structure at the tail of the electromechanical actuator of the present invention comprises a cross lug 1, a cross lug internal cover plate 2, a first resolver 3, a second resolver 4, an input shaft 5, an output shaft 6, an input gear 7, an output gear 8, a bearing, a shaft retaining ring and a hole retaining ring. There are 4 bearings in total, namely input bearings 9 and 10, and output bearings 11 and 12, the shaft retaining rings include input shaft retaining rings 13 and output shaft retaining rings 14, and the hole retaining rings include input hole retaining rings 15 and output hole retaining rings 16.

[0031] like Figure 2 , Figure 3 and Figure 6As shown, the input shaft retaining ring 13 is installed at the tail position of the circumferential surface of the input shaft 5, and the output shaft retaining ring 14 is installed at the tail position of the circumferential surface of the output shaft 6. The cross lug 1 is installed at one end of the actuator housing, and the cross lug 1 is provided with a mounting groove at one end facing the actuator housing. The cross lug 1 is provided with a first mounting convex ring and a second mounting convex ring at the bottom of the mounting groove. The inner cover plate 2 of the cross lug is located in the mounting groove and fixedly connected to the cross lug 1. The first mounting convex ring and the second mounting convex ring are located on the side of the inner cover plate 2 of the cross lug away from the actuator housing. One end of the input shaft 5 with the input shaft retaining ring 13 is extended into the first mounting convex ring, and two input bearings 9 and 10 are arranged between the input shaft 5 and the inner wall of the first mounting convex ring, and one end of the output shaft 6 with the output shaft retaining ring 14 is extended into the second mounting convex ring, and two output bearings 11 and 12 are arranged between the output shaft 6 and the inner wall of the second mounting convex ring. The circumferential surface of the input shaft 5 is provided with a first limiting convex ring, and the circumferential surface of the output shaft 6 is provided with a second limiting convex ring. The input bearings 9 and 10 are located between the first limiting convex ring and the input shaft retaining ring 13, and the output bearings 11 and 12 are located between the second limiting convex ring and the output shaft retaining ring 14. The input hole retaining ring 15 and the output hole retaining ring 16 are installed in the mounting holes of the input shaft 5 and the output shaft 6 of the cross lug 1 and pressed, that is, the input hole retaining ring 15 is installed at the end of the first mounting convex ring, and the output hole retaining ring 16 is installed at the end of the second mounting convex ring, and the input hole retaining ring 15 is located on the side of the input bearing facing the inner cover plate 2 of the cross lug, and the output hole retaining ring 16 is located on the side of the output bearing facing the inner cover plate 2 of the cross lug, so as to ensure the stability of the position of the input shaft and the output shaft when rotating. So that the input shaft 5 and the output shaft 6 are installed in the first mounting convex ring and the second mounting convex ring of the cross lug 1 through the input bearings 9-10 and the output bearings 11-12 respectively.

[0032] like Figure 3 and Figure 5 As shown, the input gear 7 and the output gear 8 are respectively installed on the input shaft 5 and the output shaft 6. After the cross lug inner cover plate 2 is aligned with the position where the shaft passes through and the screws are installed, it is tightened and installed on the cross lug 1 by 4 screws. The input shaft 5 and the output shaft 6 pass through the cross lug inner cover plate 2. The input gear 7 and the output gear 8 are located on the inner side of the cross lug inner cover plate 2, and the input gear 7 and the output gear 8 are meshed. The stator of the rotary transformer 3 is installed at the corresponding installation position of the cross lug inner cover plate 2 by means of the mounting shaft, the pressing plate, the locking nut, the gasket and the screws, as shown in FIG. Figure 4 As shown, the output shaft 6 passes through the rotor of the rotary transformer 3 and drives the rotor of the rotary transformer 3 to rotate together. The rotary transformer 3 is used to measure the number of rotations of the output shaft 6; the motor shaft is inserted into one end of the rotor of the rotary transformer 4 so that the rotor of the rotary transformer 4 is connected to the motor shaft and rotates together (as shown in the attached Figure 5As shown in the figure, the input shaft 5 is inserted into the other end of the rotor of the rotary transformer 4, and the input shaft 5 and the rotor of the rotary transformer 4 are connected by a locking nut and a gasket so that the input shaft 5 and the rotor of the rotary transformer 4 rotate together, and the stator of the rotary transformer 4 is fixedly connected to the actuator housing. The rotation of the motor shaft drives the rotary transformer 4 to rotate together, and the rotary transformer 4 drives the input shaft 5 to rotate together. When the motor shaft rotates, the rotary transformer 4 is used to measure the rotation angle of the motor shaft for servo closed-loop feedback measurement.

[0033] The above structure realizes the connection between the first rotary transformer 3, the second rotary transformer 4, the input shaft 5, the output shaft 6, the input gear 7 and the output gear 8 and the cross lug 1 and the cross lug internal cover 2. After the installation is completed, the overall structure of the servo mechanism is shown in the attached three-dimensional assembly diagram. Figure 6 shown.

[0034] The actuator position error compensation method based on the above-mentioned electromechanical actuator initial position zeroing and error compensation device includes:

[0035] The initial installation state of the motor shaft is zero position, and the zero position state of the first rotary transformer 3 and the second rotary transformer 4 when the motor shaft is zero position is recorded, and the rotor angle of the first rotary transformer 3 and the second rotary transformer 4 in the zero position state is defined as 0;

[0036] After the actuator is used, the motor shaft position when the actuator is turned off is at zero position or not at zero position; before using the actuator after being used, first start the first rotary transformer 3 and the second rotary transformer 4, and record the starting state of the rotors of the first rotary transformer 3 and the second rotary transformer 4 according to the first rotary transformer 3 and the second rotary transformer 4, and calculate the angle difference of the rotors of the first rotary transformer 3 and the second rotary transformer 4 according to the starting state;

[0037] According to the angle difference between the rotors of the first rotary transformer 3 and the second rotary transformer 4, the position of the motor shaft in the startup state is obtained;

[0038] Control the motor shaft to return to zero position from the position at startup.

[0039] Since the difference in the number of teeth between the input gear 7 and the output gear 8 is a fixed value, the difference in the number of rotations of the input shaft 5 and the output shaft 6 is fixed and non-repetitive within the working stroke of the motor shaft for every rotation of the input shaft 5. The angular difference between the rotors of the first rotary transformer 3 and the second rotary transformer 4 corresponds one to one to the position of the motor shaft. Therefore, the exact position of the motor shaft in the starting state can be calculated based on the angular difference between the rotors of the first rotary transformer 3 and the second rotary transformer 4, and the motor shaft can be controlled to rotate back to the zero position from the position in the starting state, thereby realizing the homing function of the actuator.

[0040] The tooth difference counting circle structure is adopted, which simplifies the assembly and process difficulty and improves the actuator zeroing reliability compared with the traditional displacement sensor zeroing structure.

[0041] The integrated design is adopted. The shaft is fixed by the bearing, the cover plate is installed on the lug, and the shaft is equipped with the gear and the resolver. The internal space of the lug is fully utilized to effectively reduce the axial length of the servo. The double resolver structure is built into the cross lug of the actuator. Without changing the size of the original actuator lug and ensuring the transmission efficiency and structural strength, the transmission and power components are integrated to reduce the number of single servo systems, improve the utilization efficiency of the space at the tail of the servo, and effectively reduce the weight of the servo.

[0042] The contents not described in detail in this application specification belong to the common knowledge of those skilled in the art.

[0043] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. An initial position zeroing and error compensation device for an electromechanical actuator, characterized in that: It comprises a cross lug (1), a cross lug inner cover plate (2), a first rotary transformer (3), a second rotary transformer (4), an input shaft (5), an output shaft (6) and a transmission assembly; A cross lug (1) is connected to one end of the actuator housing, and a mounting groove is provided at one end of the cross lug (1) facing the actuator housing. One end of the input shaft (5) and one end of the output shaft (6) are both rotatably connected to the cross lug (1). An inner cover plate (2) of the cross lug is located in the mounting groove and is fixedly connected to the cross lug (1). The input shaft (5) and the output shaft (6) both pass through the inner cover plate (2) of the cross lug. The stator of the first rotary transformer (3) is fixedly connected to the inner cover plate (2) of the cross support ear, and the output shaft (6) passes through the rotor of the first rotary transformer (3) and is used to drive the rotor of the first rotary transformer (3) to rotate together; The stator of the second rotary transformer (4) is fixedly connected to the actuator housing, and a motor shaft is rotatably connected inside the actuator housing. One end of the second rotary transformer (4) is connected to the motor shaft, and the other end is connected to the input shaft (5), so that the motor shaft drives the input shaft (5) to rotate; The transmission assembly is connected between the input shaft (5) and the output shaft (6), so that the input shaft (5) drives the output shaft (6) to rotate through the transmission assembly.

2. The electromechanical actuator initial position zeroing and error compensation device according to claim 1, characterized in that: The transmission assembly comprises an input gear (7) and an output gear (8); the input gear (7) is connected to the input shaft (5) and rotates together with the input shaft (5); the output gear (8) is connected to the output shaft (6) and rotates together with the output shaft (6); the input gear (7) and the output gear (8) are meshed.

3. The electromechanical actuator initial position zeroing and error compensation device according to claim 1, characterized in that: The cross support ear (1) is provided with a first mounting convex ring and a second mounting convex ring at the bottom of the mounting groove, one end of the input shaft (5) is rotatably connected in the first mounting convex ring, and one end of the output shaft (6) is rotatably connected in the second mounting convex ring.

4. The electromechanical actuator initial position zeroing and error compensation device according to claim 3, characterized in that: The input shaft (5) is rotatably connected to the inner wall of the first mounting convex ring via an input bearing, and the output shaft (6) is rotatably connected to the inner wall of the second mounting convex ring via an output bearing.

5. The electromechanical actuator initial position zeroing and error compensation device according to claim 4, characterized in that: An input shaft retaining ring (13) is installed at the end of the circumferential surface of the input shaft (5), a first position-limiting convex ring is provided on the circumferential surface of the input shaft (5), and the input bearing is located between the input shaft retaining ring (13) and the first position-limiting convex ring; An output shaft retaining ring (14) is installed at the end of the circumferential surface of the output shaft (6), a second limiting convex ring is provided on the circumferential surface of the output shaft (6), and the output bearing is located between the second limiting convex ring and the output shaft retaining ring (14).

6. The electromechanical actuator initial position zeroing and error compensation device according to claim 4, characterized in that: An input hole retaining ring (15) is installed at the end of the first mounting protruding ring, and an output hole retaining ring (16) is installed at the end of the second mounting protruding ring. The input hole retaining ring (15) is located on the side of the input bearing facing the inner cover plate (2) of the cross lug, and the output hole retaining ring (16) is located on the side of the output bearing facing the inner cover plate (2) of the cross lug.

7. The electromechanical actuator initial position zeroing and error compensation device according to claim 4, characterized in that: The input bearing and the output bearing are both provided in pairs.

8. A method for initial position zeroing and error compensation of an electromechanical actuator, characterized in that: The compensation is performed using an electromechanical actuator initial position zeroing and error compensation device as described in any one of claims 1 to 7, comprising: The initial installation state of the motor shaft is zero position, the zero position state of the first rotary transformer (3) and the second rotary transformer (4) when the motor shaft is in zero position is recorded, and the rotor angle of the first rotary transformer (3) and the second rotary transformer (4) in the zero position state is defined as 0; After the actuator is used, the motor shaft position when the actuator is turned off is at zero position or not at zero position; before using the actuator after being used, first start the first rotary transformer (3) and the second rotary transformer (4), and record the starting state of the rotors of the first rotary transformer (3) and the second rotary transformer (4) according to the first rotary transformer (3) and the second rotary transformer (4), and calculate the angle difference of the rotors of the first rotary transformer (3) and the second rotary transformer (4) according to the starting state; Obtaining the position of the motor shaft in a startup state according to the angle difference between the rotors of the first rotary transformer (3) and the second rotary transformer (4); Control the motor shaft to return to zero position from the position at startup.

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