A safety guarantee system and control method applied to a rotor dynamics test bench

Abstract

The application belongs to the technical field of helicopter rotor test, and particularly relates to a safety guarantee system applied to a rotor dynamics test bench and a control method. The lower end of the safety guarantee system is fixedly connected with a bottom bench, and the upper end is connected with a speed reducer. A rotor shaft, a hub and a rotor are sequentially arranged on the upper end of the speed reducer. The safety guarantee system comprises an upper connecting plate, a middle connecting plate, an inverse triangle support, a normal triangle support, a horizontal rolling mechanism, a pitching mechanism, a vertical mechanism and a center movable block. The inverse triangle support and the normal triangle support are connected through the vertical mechanism and are limited in vertical movement. The middle connecting plate is arranged above the inverse triangle support, and the normal triangle support is fixed on the bench. The pitching mechanism is fixed on the middle connecting plate, and the pitching mechanism is connected with the center movable block. The horizontal rolling mechanism is fixed below the upper connecting plate, and the horizontal rolling mechanism is connected with the center movable block.

Description

Technical Field

[0001] This invention belongs to the field of helicopter rotor testing technology, and specifically relates to a safety assurance system and control method for use on a rotor dynamics test bench. Background Technology

[0002] Helicopter rotor test benches are mainly used for rotor testing. They are used to conduct aerodynamic performance tests and measure the aerodynamic loads on the helicopter rotor. When aeroelastic stability dynamics problems occur between the rotor and fuselage, or between the rotor and wing, conventional test benches may be damaged or destroyed if not handled in time.

[0003] Rotor dynamics test benches have many rotating parts and complex coupling relationships between components such as rotor, fuselage, and wing. They are prone to danger during testing, which can lead to damage to the test bench in severe cases. Conventional rotor test benches lack safety protection systems and cannot provide passive vibration reduction or active braking and locking functions. Summary of the Invention

[0004] Purpose of the invention: This invention proposes a safety protection system and control method for rotor dynamics test benches, which has passively adjustable vibration damping devices in three directions of pitch, roll and vertical displacement, as well as active braking and locking functions, which can effectively protect the safety of the test bench.

[0005] Technical solution

[0006] A safety protection system for a rotor dynamics test bench, wherein the lower end of the safety protection system is fixedly connected to the bottom frame and the upper end is connected to the reducer, and a rotor shaft, a rotor hub and a rotor are sequentially installed on the upper end of the reducer;

[0007] The safety system includes: upper connecting plate, middle connecting plate, inverted triangular support, upright triangular support, roll mechanism, pitch mechanism, vertical mechanism, and center movable block;

[0008] The inverted triangular support and the equilateral triangular support are connected by a vertical mechanism, which restricts their vertical movement; the intermediate connecting plate is set above the inverted triangular support, and the equilateral triangular support is fixed on the frame;

[0009] The pitch mechanism is fixed to the intermediate connecting plate and is connected to the central movable block.

[0010] The rolling mechanism is fixed below the upper connecting plate and is connected to the central movable block.

[0011] Furthermore, the central movable block is shaped like an octagonal nut, and cylindrical connecting pins are provided in the four directions perpendicular to the axial direction: front, back, left, and right.

[0012] Furthermore, the front cylindrical connecting pin is connected to the upper swing limiting mechanism via a bearing, and the upper swing limiting mechanism is fixedly connected to the upper connecting plate; the rear cylindrical connecting pin is connected to the first brake pad via a bearing, and the first brake pad is fixedly connected to the upper connecting plate; the left cylindrical connecting pin is connected to the lower swing limiting mechanism via a bearing, and the lower swing limiting mechanism is fixedly connected to the middle connecting plate; the right cylindrical connecting pin is connected to the second brake pad via a bearing, and the second brake pad is fixedly connected to the middle connecting plate.

[0013] Furthermore, the connection relationships of the roll mechanism are as follows:

[0014] The upper end face of the first cross hinge bracket is fixedly connected to the lower end face of the upper connecting plate. The first cross hinge bracket and the rear cylindrical connecting pin bearing of the central movable block are connected, so that rolling motion can be performed.

[0015] The roll brake is fixedly connected to the first cross hinge bracket. The first brake pad passes through the gap of the roll brake and does not contact under normal circumstances. In case of an emergency, the roll brake will clamp the first brake pad tightly, so that the entire roll mechanism changes from a free roll state to a fixed connection state.

[0016] The upper end face of the first T-shaped hinge bracket is fixedly connected to the lower end face of the upper connecting plate. The first T-shaped hinge bracket, the roll lever, and the cylindrical connecting pin of the central movable block are coaxially connected by bearings, thus enabling rolling motion. The upper end of the roll lever is clamped by the roll limiting spring assembly, causing the roll lever to move along the spring extension direction. The lower end of the roll lever is connected to the lower end of the first speed controller through the first handle bearing rod. The upper end of the first speed controller is bolted to the lower end face of the upper connecting plate.

[0017] Furthermore, the pitch mechanism connections are as follows:

[0018] The lower end face of the second cross hinge bracket is fixedly connected to the upper end face of the middle connecting plate. The second cross hinge bracket and the second brake pad are coaxially connected to the right cylindrical connecting pin of the central movable block through bearings, thus enabling pitch movement. The pitch brake is fixedly connected to the second cross hinge bracket. The second brake pad passes through the gap of the pitch brake and does not contact under normal circumstances. In case of emergency, the roll brake clamps the first brake pad, thus changing the entire pitch mechanism from a free pitch state to a fixed connection state.

[0019] The lower end face of the second T-shaped hinge bracket is fixedly connected to the upper end face of the intermediate connecting plate. The second T-shaped hinge bracket and the pitch lever are coaxially connected to the left cylindrical connecting pin of the central movable block through bearings. The lower end of the pitch lever is clamped by the pitch limiting spring assembly, and the pitch lever moves along the spring extension direction. The upper end of the pitch lever is connected to the upper end of the second speed controller through the second shank bearing rod, and the lower end of the second speed controller is fixedly connected to the upper end face of the intermediate connecting plate with bolts.

[0020] Furthermore, the vertical mechanism connections are as follows:

[0021] Two rolling linear guides are symmetrically arranged on the back of the inverted triangular support. The rolling linear guides and the positive triangular support are slidably connected by four sets of linear sliders. The third brake pad is installed in the middle of the inverted triangular support. The vertical displacement brake is fixedly installed inside the vertical displacement brake connecting seat. When the linear slider moves vertically, the third brake pad moves along the middle gap of the vertical displacement brake. Under normal circumstances, they do not contact each other. In case of emergency, the vertical displacement brake will clamp the third brake pad tightly.

[0022] The upper end of the vertical displacement sensor and the buffer guide rod is connected to the lower end of the inverted triangular support, and the lower end of the vertical displacement sensor and the buffer guide rod is connected to the equilateral triangular support. A buffer spring is installed inside the buffer guide rod, and three sets of buffer rubber pads are installed between the inverted triangular support and the equilateral triangular support.

[0023] Furthermore, the system also includes: monitoring equipment;

[0024] The monitoring equipment includes: a temperature sensor mounted on the reducer and a three-dimensional displacement sensor mounted on the lower end face of the upper connecting plate.

[0025] Furthermore, the monitoring equipment also includes: a first triaxial vibration sensor installed on the end face of the upper connecting plate, and a second triaxial vibration sensor installed on the upper face of the middle connecting plate.

[0026] Furthermore, the monitoring equipment also includes two vertical displacement sensors installed between the inverted triangular support and the equilateral triangular support.

[0027] A control method for a safety assurance system applied to a rotor dynamics test bench is provided. The system is controlled by a PLC controller that receives and processes signals from temperature, displacement, and vibration sensors, comparing them with pre-set safety thresholds stored in the controller. If any signal exceeds the limit, a braking command is sent to the braking device. The braking device consists of an actuator, brake pads, and an alignment mechanism. Upon receiving the braking command, the device applies emergency braking to the motion mechanism. The actuator pushes the pitch and roll alignment mechanism to return the pitch and roll angles of the test model to zero. Another actuator pushes the brake pads to lock the vertical motion mechanism in its current position. The safety thresholds in the controller are set by the user according to the requirements of the upper-level monitoring system software, or activated by the emergency stop button on the manual control panel.

[0028] In summary, the beneficial effects of the present invention are as follows:

[0029] 1. This system can be applied to rotor dynamics test benches for passive vibration reduction in three directions: pitch, roll, and vertical displacement, thus protecting the safety of the test bench;

[0030] 2. This system can replace different lifting buffer springs, yaw limit springs and speed controllers to change the natural frequencies of the system in three directions, thereby better achieving vibration reduction adjustment of the test bench;

[0031] 3. The system can monitor the pitch angle, roll angle and vertical displacement of the test bench. It can automatically activate the emergency brake according to the set threshold, or the operator can manually activate the braking device.

[0032] 4. This system can collect and monitor the motion parameters and vibration parameters of the test bench in real time. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a safety assurance system applied to a rotor dynamics test bench.

[0034] Figure 2 This is a schematic diagram of the central movable block 13 and the cylindrical connecting pins in the four axial directions.

[0035] Figure 3 The connection status of the central live block 13.

[0036] Figure 4 This is a schematic diagram showing the connection of the first brake pad of the rolling mechanism.

[0037] Figure 5 This is a schematic diagram of the rear axial view of the safety protection device.

[0038] Figure 6 This is a front axial view of the safety protection device.

[0039] Figure 7 This is a schematic diagram showing the connection of the third brake pad of the vertical displacement brake.

[0040] Figure 8 This is a diagram showing the installation location of the safety protection device monitoring equipment.

[0041] Figure 9 This is a general framework diagram of the electrical control logic of the security system.

[0042] Figure 10 This is a functional block diagram of the supervisory control system software. Detailed Implementation

[0043] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0044] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0045] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0046] A safety assurance system for a rotor dynamics test bench mainly consists of a roll mechanism, a roll braking device, a roll constraint stiffness adjustment device, a sliding mechanism, a sliding braking device, displacement and angle monitoring equipment, and a safety protection PLC controller. It can passively mitigate vibration dispersion issues of the test bench, implement emergency braking on the test bench, and also initiate emergency shutdown of the test bench's power system by sending control commands.

[0047] During rotor dynamics testing, the lower end of the safety protection system is connected to the test bench, and the upper end is fixedly connected to the reducer. The rotor shaft, rotor hub, and rotor accessories are installed sequentially at the top of the reducer.

[0048] Working principle of the safety protection device: The PLC controller receives and processes signals from sensors such as temperature, displacement, and vibration of the test bench and model, compares them with the pre-set safety threshold values ​​stored in the controller, and if any signal exceeds the limit, sends a braking command to the braking device (outputting signals in the form of analog output, digital output, and relay output). The braking device consists of actuators, brake pads, and a centering mechanism. Upon receiving the braking command, it applies emergency braking to the motion mechanism. The actuators push the pitch and roll centering mechanisms to return the pitch and roll angles of the test model to zero, while another actuator pushes the brake pads to lock the vertical motion mechanism in its current position.

[0049] ①The mechanical structure of the protection system

[0050] The general configuration of the dynamic test rig is as follows Figure 1 As shown, the bottom platform 1 is installed on the ground platform. The lower end of the safety system 2 is fixedly connected to the upper end of the bottom platform 1. The upper end of the safety system 2 is connected to the reducer 3. The rotor shaft 4, the rotor hub 5 and the rotor 6 are installed sequentially on the upper end of the reducer 3.

[0051] A safety protection system for a rotor dynamics test bench includes: an upper connecting plate 11, an intermediate connecting plate 21, an inverted triangular support 30, an upright triangular support 32, a roll mechanism, a pitch mechanism, a vertical mechanism, and a central movable block 13.

[0052] The inverted triangular support 30 and the equilateral triangular support 32 are connected by a vertical mechanism, which restricts their vertical movement; the intermediate connecting plate 21 is set above the inverted triangular support 30, and the equilateral triangular support 32 is fixed on the platform.

[0053] The pitch mechanism is fixed on the intermediate connecting plate 21, and the pitch mechanism is connected to the central movable block.

[0054] The rolling mechanism is fixed below the upper connecting plate 11 and is connected to the central movable block.

[0055] The following provides supplementary details on the installation process for each organization.

[0056] The central movable block 13 is similar in shape to an octagonal nut, but it has cylindrical connecting pins in four directions: front, rear, left, and right. The front cylindrical connecting pin is connected to the upper swing limiting mechanism via a bearing, and the upper swing limiting mechanism is fixedly connected to the upper connecting plate 11. The rear cylindrical connecting pin is connected to the first brake pad 12 via a bearing, and the first brake pad 12 is fixedly connected to the upper connecting plate 11. The left cylindrical connecting pin is connected to the lower swing limiting mechanism via a bearing, and the lower swing limiting mechanism is fixedly connected to the middle connecting plate 21. The right cylindrical connecting pin is connected to the second brake pad 22 via a bearing, and the second brake pad 22 is fixedly connected to the middle connecting plate 21. See the detailed view of the central movable block 13. Figure 2 The connection details with the central live block 13 are shown in the image. Figure 3 .

[0057] On the back of the rolling mechanism, the upper end face of the first cross-hinged bracket 10 is bolted to the lower end face of the upper connecting plate 11. The rear cylindrical connecting pins of the first cross-hinged bracket 10, the first brake pad 12, and the central movable block 13 are coaxially connected by bearings, thus enabling rolling motion. The rolling brake 8 is fixedly connected to the first cross-hinged bracket 10. The first brake pad 12 passes through the gap of the rolling brake 8 and does not contact under normal circumstances. In case of emergency, the rolling brake 8 can clamp the first brake pad 12, thus changing the entire rolling mechanism from a freely rolling state to a fixed connection state. For details on the connection and braking of the rolling mechanism, see [link to details]. Figure 4 .

[0058] At the front of the rolling mechanism, the upper end face of the first T-shaped hinge bracket 14 is bolted to the lower end face of the upper connecting plate 11. The first T-shaped hinge bracket 14, the rolling lever 15, and the central movable block 13 are coaxially connected by a bearing through a cylindrical connecting pin. A bearing 16 is installed inside, allowing for rolling motion. The upper end of the rolling lever 15 is clamped to the rolling limit spring assembly 17, ensuring that the rolling lever 15 can only move along the spring extension direction. The spring assembly can be replaced with springs of different stiffnesses and can apply different preloads. The lower end of the rolling lever 15 is connected to the lower end of the first speed controller 19 through a first handle bearing rod 18. The upper end of the first speed controller 19 is bolted to the lower end face of the upper connecting plate 11. The speed controller can control the speed and time of the mechanical equipment moving from one place to another, and can change the control speed of its internal adjustable core to change the damping, with continuously adjustable damping. See detailed views. Figure 5 Figure 6 As shown.

[0059] On the right side of the pitch mechanism, the lower end face of the second cross-hinged bracket 20 is bolted to the upper end face of the intermediate connecting plate 21. The second cross-hinged bracket 20, the second brake pad 22, and the right cylindrical connecting pin of the central movable block 13 are coaxially connected by bearings, thus enabling pitch movement. The pitch brake 7 is fixedly connected to the second cross-hinged bracket 20. The second brake pad 22 passes through the gap of the pitch brake 7 and does not contact under normal circumstances. In case of emergency, the roll brake 7 can clamp the first brake pad 22, thus changing the entire pitch mechanism from a free pitching state to a fixed connection state. This connection mechanism and form are similar to the braking form of the roll mechanism. See detailed views. Figure 5 As shown.

[0060] On the left side of the pitch mechanism, the lower end face of the second T-shaped hinge bracket 24 is bolted to the upper end face of the intermediate connecting plate 21. The second T-shaped hinge bracket 24, the pitch lever 25, and the left cylindrical connecting pin of the central movable block 13 are coaxially connected by bearings, with bearings installed inside, allowing for rolling motion. The lower end of the pitch lever 25 is clamped to the pitch limiting spring assembly 27, ensuring that the pitch lever 25 can only move in the direction of spring extension and contraction. The spring assembly can be replaced with springs of different stiffnesses and can also apply different amounts of preload. The upper end of the pitch lever 25 is connected to the upper end of the second speed controller 29 via the second shank bearing rod 28. The lower end of the second speed controller 29 is bolted to the upper end face of the intermediate connecting plate 21. The speed controller can control the speed and time of the mechanical equipment moving from one place to another, and can change the control speed of its internal adjustable core to change the damping, with continuously adjustable damping. See detailed views. Figure 6 As shown.

[0061] The upper end of the inverted triangular support 30 of the vertical sliding mechanism is bolted to the lower end face of the intermediate connecting plate 21. Two symmetrically arranged rolling linear guides 31 are installed on the back of the inverted triangular support 30. The rolling linear guides 31 and the equilateral triangular support 32 are slidably connected by four sets of linear sliders 33, allowing the linear sliders 33 to only move vertically along the rolling linear guides 31. The third brake pad 34 is centrally mounted in the middle of the inverted triangular support 30, and the vertical displacement brake 43 is fixedly installed inside the vertical displacement brake connecting seat 9. When the linear slider 33 moves vertically, the third brake pad 34 can move along the middle gap of the vertical displacement brake 43. Under normal circumstances, they do not contact each other. In case of emergency, the vertical displacement brake 43 can clamp the third brake pad 34 tightly. (See detailed view). Figure 7 .

[0062] On the other side of the vertical sliding mechanism, two sets of vertical displacement sensors 35 and buffer guide rods 36 are provided. The upper ends of the vertical displacement sensors 35 and buffer guide rods 36 are connected to the lower end of the inverted triangular support 30, and the lower ends of the vertical displacement sensors 35 and buffer guide rods 36 are connected to the equilateral triangular support 32. A buffer spring 37 is installed inside the buffer guide rod 36. The buffer springs can be replaced and adjusted with different stiffnesses, and different preloads can be applied to the springs. Three sets of buffer rubber pads 38 are installed between the inverted triangular support 30 and the equilateral triangular support 32. In the event of a large vertical displacement change, secondary vibration reduction can be achieved. See the detailed view. Figure 5 Figure 6 As shown.

[0063] The monitoring equipment mainly includes a temperature sensor 39, mounted on the reducer 3; a first triaxial vibration sensor 40 mounted on the end face of the upper connecting plate 11; a second triaxial vibration sensor 41 mounted on the upper end face of the intermediate connecting plate 21; a triaxial displacement sensor 42 mounted on the lower end face of the upper connecting plate 11; and two vertical displacement sensors 35 mounted between the inverted triangular support 30 and the equilateral triangular support 32. See details... Figure 8 .

[0064] ② Electrical control of the protection system

[0065] This security system consists of a host security computer, a PLC controller, a data acquisition module, a temperature measurement module, a digital I / O module, tilt sensors, displacement sensors, temperature sensors, and acceleration sensors. The overall system structure is as follows: Figure 9 As shown.

[0066] The PLC controller receives and processes signals from sensors on the test bench and model, including those for temperature, displacement, and vibration. These signals are compared to pre-set safety thresholds stored in the controller. If any signal exceeds the limit, a braking command is sent to the braking device (outputting signals in analog, digital, or relay output formats). The braking device consists of actuators, brake pads, and a centering mechanism. Upon receiving the braking command, it applies emergency braking to the motion mechanism. The actuators push the pitch and roll centering mechanisms to return the pitch and roll angles of the test model to zero. Another actuator pushes the brake pads to lock the vertical motion mechanism in its current position. The safety thresholds in the controller can be set by the user according to the requirements of the upper-level monitoring system software, or the emergency stop button on the control panel can be manually used to activate the braking device of the test bench. The functional block diagram of the upper-level monitoring system software is shown below. Figure 10 .

[0067] The host computer serves as the management and monitoring center of the security system, completing communication and data exchange with the slave PLC system; and monitoring and storing the data and status information of the entire security system in real time.

[0068] ③ Working principle of the security system

[0069] When conducting rotor aeroelastic stability tests or rotor dynamic response tests, the dynamic test bench transmits energy to the rotor through the reducer and rotor shaft, driving the rotor to rotate along the rotor shaft. Due to the existence of aerodynamic imbalance forces, the rotor will undergo single-direction or multi-direction attitude changes along its disk plane, including roll, pitch, and vertical displacement. The electrical control system of the safety system will collect and feedback the current test status data in real time, including pitch and roll attitude angles, vertical displacement changes, triaxial vibration of the test bench, and reducer temperature.

[0070] When roll, pitch, or vertical movement occurs, the upper connecting plate of the safety system will first undergo corresponding motion changes. The brake pads of the roll or pitch mechanism will rotate axially around the central movable block. The roll or pitch lever mechanism on its opposite side will also rotate axially around the central movable block. The safety system will undergo vertical displacement along the buffer guide rail. Spring assemblies and speed controllers are installed at the upper and lower ends of the lever for damping adjustment, which can adjust the natural frequency of the safety system in all three directions, thereby achieving passive vibration reduction. When the test bench experiences an abnormal state that causes the roll, pitch, or vertical movement to exceed the limit, the PLC controller receives and processes signals measured by sensors such as temperature, displacement, and vibration of the test bench and model. These signals are compared with the pre-set safety threshold values ​​stored in the controller. If any signal exceeds the limit, a braking command is issued to the braking device (outputting signals in the form of analog output, digital output, and relay output). The braking device consists of actuators, brake pads, and a centering mechanism. Upon receiving a braking command, it applies emergency braking to the motion mechanism. The actuators push the pitch and roll centering mechanisms to return the pitch and roll angles of the test model to zero. Another actuator pushes the brake pads to lock the vertical motion mechanism in its current position. The friction between the brake pads and the brake unit achieves the emergency braking lock-up effect, thus protecting the safety of the test bench.

[0071] 1. The safety protection system can passively reduce vibration in three directions: pitch, roll and vertical displacement of the test bench. Vibration reduction at different frequencies can be achieved by replacing the spring mechanism with one of different stiffness.

[0072] 2. The safety protection system can remotely achieve emergency braking in three directions: pitch, roll, and vertical displacement, to protect the safety of the test bench;

[0073] 3. The safety protection system has remote power-on, power-off, and emergency stop functions. It can achieve emergency braking when the movement of the test bench exceeds the limit by setting a pre-set displacement change limit.

[0074] 4. The safety assurance system can monitor and record the displacement, tilt angle, temperature, and triaxial vibration of the test bench in real time in three directions: heading, lateral, and vertical.

[0075] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A safety protection system for a rotor dynamics test bench, wherein the lower end of the safety protection system is fixedly connected to the bottom frame, the upper end is connected to the reducer, and a rotor shaft, a rotor hub and a rotor are sequentially installed on the upper end of the reducer; Its features are: The safety system includes: upper connecting plate, middle connecting plate, inverted triangular support, upright triangular support, roll mechanism, pitch mechanism, vertical mechanism, and center movable block; The inverted triangular support and the equilateral triangular support are connected by a vertical mechanism, which restricts their vertical movement; the intermediate connecting plate is set above the inverted triangular support, and the equilateral triangular support is fixed on the frame; The pitch mechanism is fixed to the intermediate connecting plate and is connected to the central movable block. The rolling mechanism is fixed below the upper connecting plate and is connected to the central movable block.

2. The system according to claim 1, characterized in that: The central movable block is shaped like an octagonal nut, and cylindrical connecting pins are provided in the four directions of front, back, left, and right perpendicular to the axial direction.

3. The system according to claim 2, characterized in that: The front cylindrical connecting pin is connected to the upper swing limiting mechanism via a bearing, and the upper swing limiting mechanism is fixedly connected to the upper connecting plate. The rear cylindrical connecting pin is connected to the first brake pad via a bearing, and the first brake pad is fixedly connected to the upper connecting plate. The left cylindrical connecting pin is connected to the lower swing limiting mechanism via a bearing, and the lower swing limiting mechanism is fixedly connected to the middle connecting plate. The right cylindrical connecting pin is connected to the second brake pad via a bearing, and the second brake pad is fixedly connected to the middle connecting plate.

4. The system according to claim 3, characterized in that: The connection relationships of the roll mechanism are as follows: The upper end face of the first cross hinge bracket is fixedly connected to the lower end face of the upper connecting plate. The first cross hinge bracket and the rear cylindrical connecting pin bearing of the central movable block are connected, so that rolling motion can be performed. The roll brake is fixedly connected to the first cross hinge bracket. The first brake pad passes through the gap of the roll brake and does not contact under normal circumstances. In case of an emergency, the roll brake will clamp the first brake pad tightly, so that the entire roll mechanism changes from a free roll state to a fixed connection state. The upper end face of the first T-shaped hinge bracket is fixedly connected to the lower end face of the upper connecting plate. The first T-shaped hinge bracket, the roll lever, and the cylindrical connecting pin of the central movable block are coaxially connected by bearings, thus enabling rolling motion. The upper end of the roll lever is clamped by the roll limiting spring assembly, causing the roll lever to move along the spring extension direction. The lower end of the roll lever is connected to the lower end of the first speed controller through the first handle bearing rod. The upper end of the first speed controller is bolted to the lower end face of the upper connecting plate.

5. The system according to claim 4, characterized in that: The pitch mechanism connections are as follows: The lower end face of the second cross hinge bracket is fixedly connected to the upper end face of the middle connecting plate. The second cross hinge bracket and the second brake pad are coaxially connected to the right cylindrical connecting pin of the central movable block through bearings, thus enabling pitch movement. The pitch brake is fixedly connected to the second cross hinge bracket. The second brake pad passes through the gap of the pitch brake and does not contact under normal circumstances. In case of emergency, the roll brake clamps the first brake pad, thus changing the entire pitch mechanism from a free pitch state to a fixed connection state. The lower end face of the second T-shaped hinge bracket is fixedly connected to the upper end face of the intermediate connecting plate. The second T-shaped hinge bracket and the pitch lever are coaxially connected to the left cylindrical connecting pin of the central movable block through bearings. The lower end of the pitch lever is clamped by the pitch limiting spring assembly, and the pitch lever moves along the spring extension direction. The upper end of the pitch lever is connected to the upper end of the second speed controller through the second shank bearing rod, and the lower end of the second speed controller is fixedly connected to the upper end face of the intermediate connecting plate with bolts.

6. The system according to claim 5, characterized in that: The vertical mechanism connections are as follows: Two rolling linear guides are symmetrically arranged on the back of the inverted triangular support. The rolling linear guides and the positive triangular support are slidably connected by four sets of linear sliders. The third brake pad is installed in the middle of the inverted triangular support. The vertical displacement brake is fixedly installed inside the vertical displacement brake connecting seat. When the linear slider moves vertically, the third brake pad moves along the middle gap of the vertical displacement brake. Under normal circumstances, they do not contact each other. In case of emergency, the vertical displacement brake will clamp the third brake pad tightly. The upper end of the vertical displacement sensor and the buffer guide rod is connected to the lower end of the inverted triangular support, and the lower end of the vertical displacement sensor and the buffer guide rod is connected to the equilateral triangular support. A buffer spring is installed inside the buffer guide rod, and three sets of buffer rubber pads are installed between the inverted triangular support and the equilateral triangular support.

7. The system according to claim 6, characterized in that: The system also includes: monitoring equipment; The monitoring equipment includes: a temperature sensor mounted on the reducer and a three-dimensional displacement sensor mounted on the lower end face of the upper connecting plate.

8. The system according to claim 7, characterized in that: The monitoring equipment also includes: a first triaxial vibration sensor mounted on the end face of the upper connecting plate, and a second triaxial vibration sensor mounted on the upper face of the middle connecting plate.

9. The system according to claim 8, characterized in that: The monitoring equipment also includes two vertical displacement sensors installed between the inverted triangular support and the upright triangular support.

10. A control method for a safety assurance system applied to a rotor dynamics test bench, used to control the system described in any of the preceding claims, characterized in that: The PLC controller receives and processes signals from temperature, displacement, and vibration sensors, comparing them with pre-set safety thresholds stored in the controller. If any signal exceeds the limit, a braking command is sent to the braking device. The braking device consists of actuators, brake pads, and a centering mechanism. Upon receiving the braking command, it applies emergency braking to the motion mechanism. The actuators push the pitch and roll centering mechanisms to return the pitch and roll angles of the test model to zero. Another actuator pushes the brake pads to lock the vertical motion mechanism in its current position. The safety thresholds in the controller are set by the user according to the needs of the upper-level monitoring system software, or the emergency stop button on the manual control panel can be used to activate the braking device of the test bench.

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