A multi-channel loading test system and an emergency unloading control method thereof

Abstract

The application provides a multi-channel loading test system and an emergency unloading control method thereof. The system comprises: a force control electric cylinder for applying a loading force; a servo driver for driving the force control electric cylinder to act; a double control architecture composed of a coordinated loading control system and an electric cylinder motion controller, the coordinated loading control system and the electric cylinder motion controller control the force control electric cylinder through the servo driver; the electric cylinder motion controller solves the position information of the thrust rod of the force control electric cylinder in real time to obtain the deformation of the test piece under the loading condition, and calculates the stiffness of each test piece loading position under each loading stage according to the relationship between the load borne by the test piece and the deformation, and further obtains the stiffness curve of the loading position; when the electric cylinder motion controller receives an emergency trigger signal of the coordinated loading control system, the electric cylinder motion controller takes over the servo driver and controls the force control electric cylinder according to the stiffness curve, so as to realize the position control unloading of the force control electric cylinder.

Description

Technical Field

[0001] This application belongs to the field of aircraft structure or fatigue testing technology, and specifically relates to a multi-channel loading test system and its emergency unloading control method. Background Technology

[0002] Currently, aircraft structural strength testing increasingly utilizes electric cylinders for force loading and control. A coordinated loading control system applies progressively heavier loads to the test specimen according to the test load spectrum. Simultaneously, a coordination algorithm controls the coordination of multiple electric cylinders during the force loading process. The electric cylinder motion controller monitors the cylinder's motion status by controlling the speed and revolutions of the servo motor. During force loading, the electric cylinder converts rotational motion into linear motion via the servo motor and nut assembly, thereby outputting linear force to apply load to the test specimen. The load applied by the electric cylinder needs to be transmitted multiple times through the servo motor and mechanical transmission structure. In the event of electric cylinder malfunction, the reliability and speed of emergency unloading are relatively low. In particular, incoordination during unloading can directly jeopardize the safety of the test specimen. Therefore, under normal circumstances, the unloading process of the force-controlled electric cylinder should be kept as safe and controllable as possible during testing to avoid incoordination issues during emergency unloading. Summary of the Invention

[0003] The purpose of this application is to provide a multi-channel loading test system and its emergency unloading control method to solve or mitigate at least one of the problems in the background art.

[0004] The technical solution of this application is: a multi-channel loading test system, comprising:

[0005] Multiple force-controlled electric cylinders for applying loading force;

[0006] Servo drivers for driving force-controlled electric cylinders; and

[0007] A dual control architecture consisting of a coordinated loading control system and an electric cylinder motion controller, wherein the coordinated loading control system and the electric cylinder motion controller control the force-controlled electric cylinder through a servo driver:

[0008] The electric cylinder motion controller calculates the position information of the thrust rod of the force-controlled electric cylinder in real time to obtain the deformation of the test piece under load, and calculates the stiffness of each loading part of the test piece under each loading level based on the relationship between the load and deformation of the test piece, thereby obtaining the stiffness curve of the loading part.

[0009] When the electric cylinder motion controller receives an emergency trigger signal from the coordinated loading control system, it takes over the servo driver and controls the force-controlled electric cylinder according to the stiffness curve to achieve position-controlled unloading of the force-controlled electric cylinder.

[0010] Furthermore, the coordinated loading control system and the electric cylinder motion controller exchange information via DIO.

[0011] Furthermore, the force-controlled electric cylinder has a force sensor and a displacement sensor or a motor encoder to provide the loading force and elongation output by the force-controlled electric cylinder.

[0012] Furthermore, the coordinated loading control system receives feedback from the force sensor and acts as the main control system, using a servo driver to achieve force-controlled loading of the force-controlled electric cylinder.

[0013] The electric cylinder motion controller receives feedback from displacement sensors or motor encoders and acts as a slave control system, using a servo driver to monitor the motion state of the load end of the force-controlled electric cylinder.

[0014] Furthermore, the thrust rod position information of the force-controlled electric cylinder is obtained by calculating the speed and position of the servo motor inside the force-controlled electric cylinder at each loading stage.

[0015] Furthermore, the load-bearing capacity and deformation in the stiffness curve both exhibit linear changes and are symmetrical in time distribution.

[0016] On the other hand, this application provides an emergency unloading control method for a multi-channel loading test system as described in any of the above, comprising:

[0017] Step 1: The position information of the force-controlled electric cylinder thrust rod is calculated in real time by the electric cylinder motion controller to obtain the deformation of the test piece under load.

[0018] Step 2: Based on the relationship between the load and deformation of the test specimen, calculate the stiffness of each loading part of the test specimen under each loading level, and record and simulate the stiffness curve of each loading part of the test specimen through the electric cylinder motion controller.

[0019] Step 3: When the coordinated loading control system experiences interlocking or emergency abnormalities, the electric cylinder motion controller takes over the control of the force-controlled electric cylinder. According to the stiffness curve of the test piece, the position of the thrust rod of the force-controlled electric cylinder is controlled to perform position-controlled unloading. During the unloading process, the position change of each loading part of the test piece follows the stiffness change curve, thereby ensuring coordinated unloading of force through position coordination.

[0020] The multi-channel loading test system and its control method of this application realize the controllability of the unloading process of the force-controlled electric cylinder when the main control system is interlocked in an emergency, improve the unloading coordination of the force-controlled electric cylinder in the multi-channel loading test, and solve the unloading safety problem of the force-controlled electric cylinder. Attached Figure Description

[0021] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0022] Figure 1 This is a schematic diagram of the multi-channel loading test system in this application.

[0023] Figure 2 This is a schematic diagram of the load-bearing curve f(t) and deformation curve p(t) of a test specimen according to an embodiment of this application.

[0024] Figure 3 This is a schematic diagram of the controllable unloading process under emergency conditions in this application.

[0025] Figure 4 This is a schematic diagram of the state changes of the DIO interaction signal bits in this application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0027] To improve the unloading coordination of force-controlled electric cylinders in structural static / fatigue tests, ensure test safety, and avoid damage to test specimens caused by uncoordinated unloading, this application provides a multi-channel loading test system based on force-controlled electric cylinders and its emergency unloading control method.

[0028] First, such as Figure 1 The diagram shows a multi-channel loading test system based on a force-controlled electric cylinder. The test system includes:

[0029] Multiple force-controlled electric cylinders 11 are used to apply loading forces to aircraft fuselage test pieces or frame test pieces. Each force-controlled electric cylinder 11 has a force sensor 16 and a displacement sensor or motor encoder 15 inside, which can provide the loading force and elongation output by the force-controlled electric cylinder 11.

[0030] A servo driver 12 is connected to the force-controlled electric cylinder 11 and used to drive the force-controlled electric cylinder 11 to perform actions.

[0031] The dual control architecture consists of a coordinated loading control system 13 and an electric cylinder motion controller 14. The coordinated loading control system 13 and the electric cylinder motion controller 14 interact through DIO (Digital Input and Output Circuit). Both the coordinated loading control system 13 and the electric cylinder motion controller 14 are connected to the servo driver 12 so that the servo driver 12 controls the force-controlled electric cylinder 11 to output loading force.

[0032] Among them, the coordinated loading control system 13 receives feedback from the force sensor 16 of the force-controlled electric cylinder 11 and acts as the main control system, realizing force-controlled loading of the force-controlled electric cylinder 11 through the servo driver 12; the electric cylinder motion controller 14 receives feedback from the displacement sensor or motor encoder 15 of the force-controlled electric cylinder 11 and acts as the slave control system, monitoring the motion state of the load end of the force-controlled electric cylinder 11 through the servo driver 12.

[0033] During the loading process of the force-controlled electric cylinder 11, the speed and position of the servo motor inside the force-controlled electric cylinder 11 are recorded and stored in real time by the control system at each loading level. By calculating the position information of the thrust rod of the force-controlled electric cylinder 11 in real time, the deformation of the test piece under load is obtained. Based on the relationship between the load and deformation of the test piece, the stiffness of each loading part of the test piece at each loading level is calculated. The stiffness curve of each loading part of the test piece is recorded and simulated by the electric cylinder motion controller 14. The schematic diagram of the stiffness curve of the load-bearing and deformation relationship of the test piece during the structural strength test loading process is shown in the figure. Figure 2 As shown, the stiffness curve shows linear changes in both load and deformation, and exhibits a symmetrical relationship in terms of time distribution.

[0034] When the control system receives an emergency trigger signal from the main control system, the slave control system generates an unloading command and switches modes. The electric cylinder motion controller 14 controls the force-controlled electric cylinder 11 by taking over the servo driver 12, realizing position-controlled unloading of the force-controlled electric cylinder 11. The controllable unloading principle in emergency state is as follows: Figure 3 As shown, the state changes of the DIO interaction information bits are as follows: Figure 4 As shown.

[0035] The emergency unloading command is the position information of the force-controlled electric cylinder thrust rod under the current loading level of the test piece, that is, the deformation of the test piece corresponding to the stiffness of the current loading part under the current loading level. The unloading curve of each loading part of the test piece is a displacement-time curve generated based on the current stiffness of the test piece.

[0036] Ideally, the load-bearing curve and deformation curve of the test specimen change linearly during loading, meaning the stiffness of the test specimen remains constant, and the unloading curve is also linear. However, in large deformation structural strength tests, the stiffness of the test specimen changes under the influence of factors such as coupling. The displacement unloading curve of each loading part generated based on stiffness simulation can better approximate the relative positional relationship between each loading part during the loading process. During unloading, the positional change of each loading part of the test specimen follows the stiffness change curve, thereby ensuring the coordinated unloading of forces through positional coordination.

[0037] This application also provides an emergency unloading control method based on the above-mentioned multi-channel loading test system, which includes the following process:

[0038] Step 1: First, based on the electric force loading control system architecture, the position information of the force-controlled electric cylinder thrust rod is calculated in real time by the electric cylinder motion controller 14, thereby obtaining the deformation of the test piece under load.

[0039] Step 2: Based on the relationship between the load and deformation of the test piece, calculate the stiffness of each loading part of the test piece under each loading level, and record and simulate the stiffness curve of each loading part of the test piece through the electric cylinder motion controller 14.

[0040] Step 3: When the coordinated loading control system 13 experiences interlocking or emergency abnormality, the electric cylinder motion controller 14 takes over the control of the force-controlled electric cylinder 11. It controls the position of the thrust rod of the force-controlled electric cylinder according to the stiffness curve of the test piece to perform position-controlled unloading of the force-controlled electric cylinder. During the unloading process, the position change of each loading part of the test piece follows the stiffness change curve, thereby ensuring the coordinated unloading of force through position coordination.

[0041] The multi-channel loading test system and its control method of this application realize the controllability of the unloading process of the force-controlled electric cylinder when the main control system is interlocked in an emergency, improve the unloading coordination of the force-controlled electric cylinder in the multi-channel loading test, and solve the unloading safety problem of the force-controlled electric cylinder.

[0042] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A multi-channel loading test system, characterized in that, include: Multiple force-controlled electric cylinders for applying loading force, wherein the force-controlled electric cylinder has a force sensor and a displacement sensor or a motor encoder to provide the loading force and elongation output by the force-controlled electric cylinder; Servo driver used to drive force-controlled electric cylinders to perform actions; as well as A dual control architecture consisting of a coordinated loading control system and an electric cylinder motion controller, wherein the coordinated loading control system and the electric cylinder motion controller control the force-controlled electric cylinder through a servo driver: The electric cylinder motion controller calculates the position information of the thrust rod of the force-controlled electric cylinder in real time to obtain the deformation of the test piece under load, and calculates the stiffness of each loading part of the test piece under each loading level based on the relationship between the load and deformation of the test piece, thereby obtaining the stiffness curve of the loading part. When the electric cylinder motion controller receives an emergency trigger signal from the coordinated loading control system, it takes over the servo driver and controls the force-controlled electric cylinder according to the stiffness curve to achieve position-controlled unloading of the force-controlled electric cylinder.

2. The multi-channel loading test system as described in claim 1, characterized in that, The coordinated loading control system and the electric cylinder motion controller exchange information via DIO.

3. The multi-channel loading test system as described in claim 1, characterized in that, The force-controlled electric cylinder has a force sensor and a displacement sensor or a motor encoder to provide the loading force and elongation output by the force-controlled electric cylinder.

4. The multi-channel loading test system as described in claim 3, characterized in that, The coordinated loading control system receives feedback from the force sensor and acts as the main control system, using a servo driver to achieve force-controlled loading of the force-controlled electric cylinder. The electric cylinder motion controller receives feedback from displacement sensors or motor encoders and acts as a slave control system, using a servo driver to monitor the motion state of the load end of the force-controlled electric cylinder.

5. The multi-channel loading test system as described in claim 4, characterized in that, The thrust rod position information of the force-controlled electric cylinder is obtained by calculating the speed and position of the servo motor inside the force-controlled electric cylinder at each loading stage.

6. The multi-channel loading test system as described in claim 5, characterized in that, The stiffness curve shows linear changes in both load and deformation, and exhibits a symmetrical relationship in terms of time distribution.

7. An emergency unloading control method for a multi-channel loading test system as described in any one of claims 1 to 6, characterized in that, include: Step 1: The position information of the force-controlled electric cylinder thrust rod is calculated in real time by the electric cylinder motion controller to obtain the deformation of the test piece under load. Step 2: Based on the relationship between the load and deformation of the test specimen, calculate the stiffness of each loading part of the test specimen under each loading level, and record and simulate the stiffness curve of each loading part of the test specimen through the electric cylinder motion controller. Step 3: When the coordinated loading control system experiences interlocking or emergency abnormalities, the electric cylinder motion controller takes over the control of the force-controlled electric cylinder. According to the stiffness curve of the test piece, the position of the thrust rod of the force-controlled electric cylinder is controlled to perform position-controlled unloading. During the unloading process, the position change of each loading part of the test piece follows the stiffness change curve, thereby ensuring coordinated unloading of force through position coordination.

Images