A scaled magnetic levitation train wind tunnel aerodynamic load and dynamic response test system

Abstract

This invention provides a wind tunnel aerodynamic load and dynamic response testing system for a scaled-down maglev train, belonging to the technical field of rail transit aerodynamic testing and vehicle system dynamics testing. It includes a wind tunnel test section, an integral yaw turntable, a scaled-down guide rail model, and a scaled-down maglev train model. The wind tunnel test section is enclosed by an air inlet, an air outlet, and side walls. The integral yaw turntable is located at the bottom of the wind tunnel test section. The scaled-down guide rail model is fixed on the integral yaw turntable, and the scaled-down maglev train model is positioned above the scaled-down guide rail model. The scaled-down guide rail model includes a track beam and an air gap sensor, with the air gap sensor mounted on the track beam. This system addresses the problems in existing wind tunnel tests where external support structures interfere with the train-guide rail gap flow field, rigid fixing methods cannot reflect the maglev train's suspension load transmission relationship, and aerodynamic forces and dynamic responses are difficult to measure simultaneously.

Description

Technical Field

[0001] This invention relates to the field of rail transit aerodynamic testing and vehicle system dynamics testing technology, and in particular to a scaled-down maglev train wind tunnel aerodynamic load and dynamic response testing system. Background Technology

[0002] High-speed maglev trains operate at high speeds, and the average and pulsating aerodynamic forces on the train surface not only affect aerodynamic drag, lift, lateral forces, and aerodynamic moments in all directions, but also cause changes in suspension gaps, car body vibration, and attitude response through the load transmission paths between the car body, secondary suspension, suspension frame, suspension electromagnets, and guide rails. Therefore, when conducting wind tunnel tests on maglev trains, in addition to obtaining aerodynamic forces and surface pressures, it is also necessary to study the coupling relationship between aerodynamic forces and suspension control and car body dynamics.

[0003] Current wind tunnel tests for maglev trains typically use support rods, belly supports, tail supports, or rigid force-measuring brackets to fix the train model within the wind tunnel test section, and obtain aerodynamic forces through external or bottom-mounted force-measuring balances. These mechanical support structures may occupy the gap area between the bottom of the car body and the guide rails, or enter the external flow field around the train model, thereby altering the effective cross-section, local boundary layer, and vortex structure of the gap flow channel. The support structure itself also generates additional aerodynamic forces and interference loads, requiring complex support interference corrections. Simultaneously, traditional rigid supports restrict the vertical, lateral, roll, pitch, and yaw movements of the train model, making it impossible to maintain the actual system relationship of force transmission from the car body via secondary suspension and from the guide rails via electromagnetic action. Furthermore, it is difficult to simultaneously measure aerodynamic forces, levitation gap, levitation electromagnet current, and car body dynamic response in the same wind tunnel test. Although the external magnetic suspension device in the wind tunnel can reduce mechanical support interference, its magnetic field is usually directly applied to the magnet inside the model by coils outside the wind tunnel test section. This is different from the interaction between the levitation electromagnet and the guide rail of the maglev train itself, and therefore cannot be directly used to simulate the vehicle-track coupling dynamics of maglev vehicles.

[0004] Furthermore, the maglev train needs to be tested at multiple yaw angles under crosswind conditions. Rotating only the train model without simultaneously rotating the guide rail model will alter the relative position and levitation gap between the train and the guide rail. Repeated disassembly and reassembly of the train and guide rail can easily introduce geometric installation errors, sensor zero-point drift, and differences in levitation control parameters. Therefore, it is necessary to provide a wind tunnel testing system that allows the scaled-down maglev train model to remain above the scaled-down guide rail model via its own levitation and guiding electromagnetic action, and to change the yaw angle of the entire train-guide rail system. This would reduce the interference of external mechanical supports on the flow field and simultaneously acquire aerodynamic loads and dynamic responses. Summary of the Invention

[0005] The purpose of this invention is to provide a scaled-down maglev train wind tunnel aerodynamic load and dynamic response test system to solve the problems in existing wind tunnel tests, such as external support structures interfering with the flow field between the train and the guide rail, rigid fixing methods failing to reflect the transmission relationship of maglev train suspension loads, and difficulty in simultaneously measuring aerodynamic forces and dynamic responses.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A wind tunnel aerodynamic load and dynamic response test system for a scaled-down maglev train includes a wind tunnel test section, an integral yaw turntable, a scaled-down guide rail model, and a scaled-down maglev train model. The wind tunnel test section is enclosed by a test section air inlet, a test section air outlet, and a test section side wall. The integral yaw turntable is located at the bottom of the wind tunnel test section. The scaled-down guide rail model is fixed on the integral yaw turntable, and the scaled-down maglev train model is located above the scaled-down guide rail model. The integral yaw turntable is used to drive the scaled-down guide rail model and the scaled-down maglev train model to rotate as a whole around a vertical axis. The scaled-down guide rail model includes a track beam and an air gap sensor. The air gap sensor is located on the track beam and includes a sensor for measuring the vertical suspension gap and / or a sensor for measuring the lateral guide gap.

[0007] The scaled-down maglev train model includes an aerodynamic outer shell, an internal six-component force measurement unit, a car body inertial frame, a scaled-down secondary suspension, lateral guide electromagnets, vertical levitation electromagnets, dynamic response sensors, and a levitation control and data acquisition unit. The aerodynamic outer shell is connected to the car body inertial frame via the internal six-component force measurement unit. The car body inertial frame is connected to the bottom of the car body via the scaled-down secondary suspension. The lateral guide electromagnets and vertical levitation electromagnets are located inside the rail-clamping hooks of the scaled-down maglev train model, forming non-contact electromagnetic interactions with the guiding and levitation surfaces of the corresponding track beams, respectively. The levitation control and data acquisition unit is connected to the air gap sensor, the internal six-component force measurement unit, the lateral guide electromagnets, the vertical levitation electromagnets, and the dynamic response sensor. The levitation control and data acquisition unit is used to maintain a preset levitation state and simultaneously acquire aerodynamic load, levitation gap, electromagnet current, and dynamic response data.

[0008] Furthermore, the built-in six-component force measurement unit is a single six-component balance or an equivalent six-component force measurement assembly composed of multiple multi-axis force sensors.

[0009] The inertial frame of the vehicle body is provided with a mass adjustment section and an inertia adjustment section. The mass adjustment section and the inertia adjustment section are used to adjust the total mass, center of gravity position, and roll, pitch and yaw rotational inertia of the scaled-down maglev train model.

[0010] Furthermore, the scaled-down binary suspension includes at least one of a vertical elastic element, a lateral elastic element, a longitudinal elastic element, and a damping element, and the stiffness and / or damping of the scaled-down binary suspension can be set by replacing the elastic element, changing the installation position, or adjusting the damping parameters.

[0011] Furthermore, the dynamic response sensor is disposed at at least one position in the aerodynamic outer shell, the inertial frame of the vehicle body, and the bottom surface of the scaled-down maglev train model. The dynamic response sensor includes at least one of an acceleration sensor, an angular velocity sensor, an attitude sensor, and a vehicle body relative displacement sensor.

[0012] Furthermore, the suspension control and data acquisition unit includes a real-time controller, an electromagnet power drive module, a current detection module, and a synchronous data acquisition module. The current detection module is connected to the power supply circuit of the lateral guide electromagnet and / or the vertical suspension electromagnet. The synchronous data acquisition module is used to synchronously acquire the outputs of the dynamic response sensor, the built-in six-component force measurement unit, the air gap sensor, and the current detection module. The real-time controller is used to receive the measurement signal from the air gap sensor, compare the measured gap with the target gap, and generate an electromagnet current command based on the deviation. The electromagnet power drive module supplies power to the lateral guide electromagnet and the vertical suspension electromagnet according to the current command to adjust the guide gap and the suspension gap in a closed loop.

[0013] Furthermore, the suspension control and data acquisition unit has an aerodynamic load test mode and an aerodynamic-power coupling response test mode.

[0014] In the aerodynamic load test mode, the suspension control and data acquisition unit maintains the preset suspension gap and guide gap and acquires six-component loads.

[0015] In the aerodynamic-dynamic coupling response test mode, the scaled-down secondary suspension retains the motion of the inertial frame relative to the scaled-down vehicle body. The suspension control and data acquisition unit synchronously collects data from the air gap sensor, dynamic response sensor, electromagnet drive current, and suspension control quantity.

[0016] A method for using a scaled-down maglev train wind tunnel aerodynamic load and dynamic response testing system includes the following steps: Step S1: Based on the geometric and dynamic parameters of the target maglev train and guide rail, determine the scaled-down maglev train model, scaled-down guide rail model, car body mass and moment of inertia, stiffness and damping of the scaled-down secondary suspension, and target value of suspension gap.

[0017] Step S2: Fix the scaled-down guide rail model to the overall yaw turntable, activate the vertical suspension electromagnet and the lateral guide electromagnet to make the scaled-down maglev train model reach the preset suspension state relative to the scaled-down guide rail model, and perform windless baseline calibration on the built-in six-component force measurement unit, air gap sensor and dynamic response sensor. The suspension control and data acquisition unit records the electromagnet current baseline and suspension control quantity baseline.

[0018] Step S3: The scaled-down guide rail model and the scaled-down maglev train model are rotated together to the target yaw angle and locked by the overall yaw turntable to confirm that the relative position and suspension gap of the scaled-down maglev train model and the scaled-down guide rail model meet the test requirements.

[0019] Step S4: Start the wind tunnel and adjust the wind speed to the target wind speed. Through the suspension control and data acquisition unit, synchronously acquire the six-component load signal output by the built-in six-component force measurement unit, the vertical suspension gap signal and / or lateral guide gap signal output by the air gap sensor, the linear acceleration signal, angular velocity signal, attitude angle signal and / or vehicle body relative displacement signal output by the dynamic response sensor, as well as the actual drive current and suspension control command of the lateral guide electromagnet and / or vertical suspension electromagnet according to a unified sampling clock.

[0020] Step S5: Based on the windless baseline data at the target yaw angle collected in Step S3 and the windy test data collected in Step S4, the measurement channels of the built-in six-component force measurement unit are coupled and corrected using a pre-calibrated six-component calibration matrix. The windy output and windless output under the same yaw angle, the same suspension gap setpoint, and the same suspension control parameters are differentially analyzed. Based on the mass, center of gravity position, and moment of inertia of the aerodynamic outer shell, as well as the linear acceleration and angular acceleration detected or calculated by the dynamic response sensor, the differential six-component load is inertially corrected to obtain the aerodynamic force and aerodynamic torque of the scaled-down maglev train model. Based on the vertical suspension gap signal, the lateral guide gap signal, the dynamic response signal, the actual driving current of the electromagnet, and the suspension control command, the suspension gap response, vibration response, attitude response, and electromagnetic control response of the scaled-down maglev train model are obtained.

[0021] Step S6: Change at least one of the target wind speed, target yaw angle, suspension control parameters, and stiffness or damping parameters of the scaled-down secondary suspension to conduct the test for the next target operating condition. When only the target wind speed is changed, keep the yaw angle, suspension clearance setpoint, suspension control parameters, and scaled-down secondary suspension parameters unchanged, and repeat steps S4 and S5. When the target yaw angle, suspension control parameters, or scaled-down secondary suspension parameters are changed, re-establish the preset suspension state under the new target operating condition and collect the corresponding windless baseline data, and then repeat steps S4 and S5 to obtain aerodynamic load and dynamic response data under different operating conditions.

[0022] Further, in step S5, a pre-calibrated six-component calibration matrix is ​​used to couple and correct the output of each measurement channel of the built-in six-component force measurement unit. The wind-driven output after coupling correction is then compared with the windless output under the same yaw angle, the same suspension gap setting value, the same guide gap setting value, the same suspension control parameters, and the same scaled-down secondary suspension parameters. Based on the mass, center of gravity position, and moment of inertia of the aerodynamic outer shell, as well as the linear acceleration and angular acceleration of the aerodynamic outer shell, the six-component load after differentiation is inertially corrected to obtain the aerodynamic force and aerodynamic torque of the scaled-down maglev train model.

[0023] Furthermore, between different yaw angle tests, the scaled-down guide rail model and the scaled-down maglev train model maintained the same installation relationship, and the suspension gap was controlled within the allowable error range of the same set value.

[0024] Advantages of this invention: 1. The scaled-down maglev train model relies on vertical levitation electromagnets and lateral guide electromagnets set inside the train model and guide rail model to form the main support and guidance functions. It does not require mechanical support rods that are continuously connected to the wind tunnel wall or turntable on the outside of the car body, which helps to reduce the interference of the support structure on the external flow field of the train and the flow field of the train-guide rail suspension gap.

[0025] 2. An internal six-component force measurement unit is set between the aerodynamic outer shell and the inertial frame of the vehicle body. The aerodynamic force is transmitted and measured through the load path inside the model, and the aerodynamic force and aerodynamic torque can be obtained without occupying the main channel of the train-guide rail gap.

[0026] 3. The inertial frame of the vehicle body is connected to the bottom of the vehicle body via a scaled-down secondary suspension. The vehicle body interacts with the scaled-down guide rail model through vertical suspension electromagnets and lateral guide electromagnets. The vehicle body motion state, electromagnet drive current and suspension control quantity are acquired synchronously through dynamic response sensors and suspension control and data acquisition units. The load transfer relationship between the aerodynamic outer shell, secondary suspension, vehicle body and guide rail can be preserved, and the aerodynamic load, suspension gap, electromagnet current and vehicle body dynamic response can be measured simultaneously.

[0027] 4. The scaled-down guide rail model and the scaled-down maglev train model are installed together on the overall yaw turntable. When the yaw angle is changed, the relative geometric relationship between the train and the guide rail, the suspension gap and the sensor installation relationship remain unchanged, which can reduce the error caused by repeated disassembly and assembly.

[0028] 5. The vehicle body mass, center of gravity, moment of inertia, and stiffness and damping of the scaled-down secondary suspension are adjustable. It can perform functionally equivalent scaling based on the dynamic parameters of the target vehicle and conduct comparative tests under different suspension control parameters and suspension parameters.

[0029] 6. The same test system can simultaneously perform steady and pulsating aerodynamic tests and aerodynamic-suspended-vehicle dynamic coupling response tests, improving the consistency between wind tunnel test data. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the system of the present invention. The left side shows the scaled-down guide rail model and the scaled-down maglev train model in the state of the reference yaw angle, and the right side shows the state after the overall yaw turntable drives the scaled-down guide rail model and the scaled-down maglev train model to rotate.

[0031] Figure 2 This is a partial cross-sectional view of the scaled-down maglev train model and the scaled-down guide rail model in this invention. The left side is a partial three-dimensional cross-sectional view, and the right side is a schematic diagram of the transverse cross-section.

[0032] In the diagram: 1. Test section air inlet; 2. Test section air outlet; 3. Test section side wall; 4. Overall yaw turntable; 5. Scaled-down guide rail model; 6. Scaled-down maglev train model; 501. Track beam; 502. Air gap sensor; 601. Pneumatic outer shell; 602. Built-in six-component force measurement unit; 603. Car body inertial frame; 604. Scaled-down secondary suspension; 605. Lateral guide electromagnet; 606. Vertical suspension electromagnet; 607. Dynamic response sensor; 608. Suspension control and data acquisition unit. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0034] like Figure 1As shown, a wind tunnel aerodynamic load and dynamic response test system for a scaled-down maglev train includes a wind tunnel test section, an integral yaw turntable 4, a scaled-down guide rail model 5, and a scaled-down maglev train model 6. The wind tunnel test section is enclosed by a test section inlet 1, a test section outlet 2, and a test section side wall 3. The incoming flow enters through the test section inlet 1, flows through the scaled-down maglev train model 6 and the scaled-down guide rail model 5, and exits through the test section outlet 2. The integral yaw turntable 4 is located at the bottom of the wind tunnel test section, and its rotation center is preferably located near the geometric center of the scaled-down maglev train model 6 or a selected aerodynamic torque reference point. The scaled-down guide rail model 5 is fixed on the overall yaw turntable 4, and the scaled-down maglev train model 6 is set above the scaled-down guide rail model 5. The overall yaw turntable 4 is used to drive the scaled-down guide rail model 5 and the scaled-down maglev train model 6 to rotate as a whole around the vertical axis. When the overall yaw turntable 4 rotates, the scaled-down guide rail model 5 and the scaled-down maglev train model 6 rotate synchronously as a whole. Therefore, the longitudinal, lateral and vertical positional relationships of the scaled-down maglev train model 6 relative to the scaled-down guide rail model 5 remain unchanged.

[0035] The upper surface of the overall yaw turntable 4 is preferably flush with or nearly flush with the bottom plate of the wind tunnel test section. A ring-shaped flexible sealing strip, a labyrinth seal structure, or a removable rectifier cover can be installed between the turntable perimeter and the test section bottom plate to reduce leakage flow and additional disturbances caused by turntable gaps. The yaw angle can be continuously adjusted according to test requirements or adjusted in stages according to preset angles.

[0036] like Figure 2 As shown, the scaled-down guide rail model 5 includes a track beam 501 and an air gap sensor 502. The external contour, levitation surface, guiding surface, and flow channel shape corresponding to the bottom of the train of the track beam 501 are geometrically scaled down according to the target maglev system. The track beam 501 can be formed by combining a non-magnetic skeleton with local ferromagnetic reaction components, so that the magnetic circuits of the vertical levitation electromagnet 606 and the lateral guiding electromagnet 605 are concentrated in the train-guide rail interaction area, while reducing the additional magnetic attraction in the non-interaction areas.

[0037] An air gap sensor 502 is mounted on the track beam. The air gap sensor 502 includes a sensor for measuring the vertical suspension gap and / or a sensor for measuring the lateral guide gap, respectively detecting the suspension gap between the vertical suspension electromagnet 606 and the suspension surface, and the guide gap between the lateral guide electromagnet 605 and the guide surface. The air gap sensor 502 can be an eddy current type, inductive type, laser type, or other non-contact displacement sensor. The detection end of the air gap sensor is preferably positioned at a location that does not significantly protrude from the guide rail surface to avoid altering the main gap flow channel.

[0038] The scaled-down maglev train model 6 can be a single-car model or a multi-car formation model consisting of a lead car, middle car, and tail car. The scaled-down maglev train model 6 includes an aerodynamic outer shell 601, an internal six-component force measurement unit 602, a car body inertial frame 603, a scaled-down secondary suspension 604, a lateral guide electromagnet 605, a vertical levitation electromagnet 606, a dynamic response sensor 607, and a levitation control and data acquisition unit 608. The aerodynamic outer shell 601 is geometrically scaled down according to the shape of the target train, and its outer surface is used to form the measured aerodynamic boundary. The aerodynamic outer shell 601 is connected to the car body inertial frame 603 through the internal six-component force measurement unit 602. The internal six-component force measurement unit 602 can be a strain gauge six-component balance, a piezoelectric six-component sensor, or a combination of several triaxial or multiaxial sensors arranged in spatial positions. The inertial frame 603 of the car body is connected to the bottom surface of the car body through a scaled-down secondary suspension 604. Lateral guide electromagnets 605 and vertical levitation electromagnets 606 are located inside the rail-clamping hooks of the scaled-down maglev train model 6, forming non-contact electromagnetic interactions with the guiding and levitation surfaces of the corresponding track beams 501, respectively. The levitation control and data acquisition unit 608 is located inside the scaled-down maglev train model 6 and is connected to the air gap sensor 502, the built-in six-component force measurement unit 602, the lateral guide electromagnet 605, the vertical levitation electromagnet 606, and the dynamic response sensor 607. The levitation control and data acquisition unit 608 is used to maintain a preset levitation state and simultaneously collect aerodynamic load, levitation gap, electromagnet current, and dynamic response data. No continuously connected external mechanical support rods are installed between the scaled-down maglev train model 6 and the wind tunnel test section, and no through-type force measurement support structure is installed in the main levitation gap channel between the scaled-down maglev train model 6 and the scaled-down guide rail model 5. To prevent the model from exceeding its safe travel length along the guide rail during testing, a conventional safety limiting structure can be installed at the end or inside of the track beam 501. This safety limiting structure is located outside the main flow area of ​​the suspension gap, and its stiffness and load can be pre-calibrated. This safety limiting structure does not provide vertical support or lateral guidance for the train model.

[0039] In a preferred embodiment of the present invention, the built-in six-component force measurement unit 602 is a single six-component balance or an equivalent six-component force measurement assembly composed of multiple multi-axis force sensors. Apart from the built-in six-component force measurement unit 602 and the flexible wires, no rigid force transmission connection bypassing the built-in six-component force measurement unit 602 is provided between the aerodynamic outer housing 601 and the vehicle body inertial frame 603. This allows the drag, lateral force, lift, roll moment, pitch moment, and yaw moment acting on the aerodynamic outer housing 601 to be transmitted through the built-in six-component force measurement unit 602.

[0040] The force measurement center and coordinate system of the built-in six-component force measurement unit 602 can be set according to the aerodynamic torque reference point of the train model. Before the test, multi-component calibration is performed using forces and torques of known direction and magnitude to obtain the sensitivity matrix and channel coupling correction matrix of each measurement channel. Since the aerodynamic outer shell 601 moves with the vehicle body during the dynamic response test, inertial compensation can be performed on the force measurement output based on the mass, center of gravity, moment of inertia, linear acceleration, and angular acceleration of the aerodynamic outer shell 601 during data processing.

[0041] The vehicle body inertial frame 603 is equipped with a mass adjustment unit and an inertia adjustment unit. These units are used to adjust the total mass, center of gravity position, and roll, pitch, and yaw moments of inertia of the scaled-down maglev train model 6. The mass adjustment unit can be a counterweight that is movable along the longitudinal, lateral, and vertical directions of the vehicle body, while the inertia adjustment unit can be a detachable counterweight located at both ends or sides of the vehicle body. This allows for the adjustment of the total mass, center of gravity position, roll moment of inertia, pitch moment of inertia, and yaw moment of inertia of the scaled-down model. The mass and inertia parameters are determined based on a selected dynamic similarity criterion between the target vehicle and the scaled-down model.

[0042] In a preferred embodiment of the present invention, the scaled-down binary suspension 604 includes at least one of a vertical elastic element, a lateral elastic element, a longitudinal elastic element, and a damping element, and the stiffness and / or damping of the scaled-down binary suspension 604 can be set by replacing the elastic element, changing the installation position, or adjusting the damping parameters. The scaled-down binary suspension 604 may include springs, rubber elements, flexible leaf springs, viscous dampers, magnetorheological dampers, or equivalent elastic damping assemblies, and provides predetermined equivalent stiffness and damping in the vertical, lateral, longitudinal, and anti-roll directions, respectively. Preferably, the scaled-down binary suspension 604 employs a replaceable structure to allow for changes in suspension parameters while maintaining the aerodynamic shape.

[0043] The vertical levitation electromagnet 606 and the levitation surface of the track beam 501 form an attractive or repulsive levitation effect to bear the main vertical load of the scaled-down maglev train model 6 and adjust the levitation gap. The lateral guide electromagnet 605 and the guide surface of the track beam 501 form a lateral electromagnetic effect to adjust the lateral position of the train model relative to the guide rail model. Each electromagnet can be controlled independently or coordinated according to the front-back and left-right positions to generate vertical force, lateral force, and restoring torque in the roll, pitch, and yaw directions.

[0044] In a preferred embodiment of the present invention, the dynamic response sensor 607 is disposed at at least one position in the aerodynamic outer shell 601, the vehicle body inertial frame 603, and the bottom surface of the scaled-down maglev train model 6. The dynamic response sensor 607 includes at least one of an acceleration sensor, an angular velocity sensor, an attitude sensor, and a vehicle body relative displacement sensor. Figure 2 In one embodiment shown, a dynamic response sensor 607 is mounted on the vehicle body inertial frame 603. Through the dynamic response sensor 607 and the suspension control and data acquisition unit 608, the vertical and lateral vibrations of the vehicle body, roll angle, pitch angle, yaw angle, relative displacement of the vehicle body, suspension gap fluctuation, electromagnet current change, and suspension control parameters can be obtained.

[0045] In a preferred embodiment of the present invention, the suspension control and data acquisition unit 608 includes a real-time controller, an electromagnet power drive module, a current detection module, and a synchronous data acquisition module. The current detection module is connected to the power supply circuit of the lateral guide electromagnet 605 and / or the vertical suspension electromagnet 606. The synchronous data acquisition module is used to synchronously acquire the outputs of the dynamic response sensor 607, the built-in six-component force measurement unit 602, the air gap sensor 502, and the current detection module. The real-time controller is used to receive the measurement signal from the air gap sensor 502, compare the measured gap with the target gap, and generate an electromagnet current command based on the deviation. The electromagnet power drive module supplies power to the lateral guide electromagnet 605 and the vertical suspension electromagnet 606 according to the current command to adjust the guide gap and the suspension gap in a closed loop.

[0046] As a preferred embodiment of the present invention, the suspension control and data acquisition unit 608 has an aerodynamic load test mode and an aerodynamic-power coupling response test mode.

[0047] In the aerodynamic load test mode, the suspension control and data acquisition unit 608 maintains the preset suspension gap and guide gap and acquires six-component loads. In this mode, the suspension controller maintains the preset average suspension gap and guide gap, and the wind tunnel gradually rises to the target wind speed; the built-in six-component force measurement unit 602 directly measures the six-component load transmitted from the aerodynamic outer shell 601 to the vehicle body inertial frame 603. Through windless baseline subtraction, channel coupling correction, and necessary inertial compensation, the average aerodynamic force, pulsating aerodynamic force, and stress torque can be obtained.

[0048] In the aerodynamic-dynamic coupling response test mode, the scaled-down secondary suspension 604 retains the motion of the vehicle body's inertial frame 603 relative to the center of mass of the scaled-down maglev train model 6. The suspension control and data acquisition unit 608 simultaneously acquires data from the air gap sensor 502, the dynamic response sensor 607, the electromagnet drive current, and the suspension control quantity. In this mode, the scaled-down secondary suspension 604 maintains the equivalent stiffness and damping corresponding to the target vehicle. The suspension control and data acquisition unit 608 maintains a safe suspension state according to a preset control law, but does not rigidly lock the target dynamic response of the vehicle body's inertial frame 603. The vehicle body vibration and attitude changes caused by wind load are measured by the dynamic response sensor 607, and the electromagnet drive current and suspension control quantity are recorded by the suspension control and data acquisition unit 608. Simultaneously, the suspension gap is acquired to analyze the coupling relationship between aerodynamic forces, suspension control action, and vehicle body response.

[0049] When using this system for testing, the geometric scaling ratio of the model is first determined based on the wind tunnel size and blockage ratio, and a scaled-down guide rail model 5 and a scaled-down maglev train model 6 are fabricated. Then, the inertial frame 603, the scaled-down secondary suspension 604, and the electromagnet control parameters are configured according to the target vehicle's mass, center of gravity, moment of inertia, suspension parameters, and levitation control characteristics. After the model is installed, levitation control is activated under windless conditions to stabilize the train model. The zero point of the air gap sensor 502, the zero point of the built-in six-component force measurement unit 602, and the baseline of the dynamic response sensor 607 are recorded sequentially. Simultaneously, the levitation control and data acquisition unit 608 records the electromagnet current baseline and the control quantity baseline.

[0050] After the no-wind calibration is completed, the overall yaw turntable 4 is driven to rotate to the first target yaw angle and locked. During the wind tunnel acceleration process, the output of the air gap sensor 502, the output of the dynamic response sensor 607, and the electromagnet current and control status recorded by the suspension control and data acquisition unit 608 are monitored in real time. When any parameter of the suspension gap, guide gap, electromagnet current, or vehicle attitude exceeds the preset safety range, the controller reduces the wind tunnel wind speed, increases the safety control effect, or terminates the test. After reaching the target wind speed, it is maintained for a preset time and data is collected synchronously. After completing the current working condition, the wind speed is reduced, and the yaw angle or suspension and control parameters are changed again to repeat the test.

[0051] During data processing, the wind-driven output of the built-in six-component force measurement unit 602 is differentially compared with the windless output at the corresponding yaw angle to eliminate baseline loads caused by gravity, assembly preload, and static electromagnetic effects. In dynamic testing, the linear and angular accelerations measured by the dynamic response sensor 607 are used to correct the inertial load on the aerodynamic outer shell 601. The electromagnet current and suspension control quantities recorded by the air gap sensor 502, dynamic response sensor 607, and suspension control and data acquisition unit 608 are synchronized with the six-component aerodynamic data to obtain the aerodynamic spectrum, suspension gap fluctuations, electromagnet current changes, vehicle body vibration amplitude, phase relationship, and aerodynamic-suspension coupling characteristics.

[0052] This invention does not limit the specific suspension system of the scaled-down maglev train model 6. The vertical suspension electromagnet 606 and the lateral guide electromagnet 605 can be electromagnetic attraction type, permanent magnet-electromagnetic hybrid type or other structures that can maintain the model's suspension and guidance at zero operating speed, depending on the target maglev system; the magnetic reaction force component, cross-sectional shape and installation position of the track beam 501 can be matched with the corresponding suspension system.

[0053] A method for using a scaled-down maglev train wind tunnel aerodynamic load and dynamic response testing system includes the following steps: Step S1: Based on the geometric and dynamic parameters of the target maglev train and guide rail, determine the target values ​​of the scaled-down maglev train model 6, the scaled-down guide rail model 5, the car body mass and moment of inertia, the stiffness and damping of the scaled-down secondary suspension 604, and the suspension gap.

[0054] Step S2: Fix the scaled-down guide rail model 5 to the overall yaw turntable 4, activate the vertical levitation electromagnet 606 and the lateral guide electromagnet 605 to make the scaled-down maglev train model 6 reach the preset levitation state relative to the scaled-down guide rail model 5, and perform windless baseline calibration on the built-in six-component force measurement unit 602, air gap sensor 502 and dynamic response sensor 607. The levitation control and data acquisition unit 608 records the electromagnet current baseline and levitation control quantity baseline.

[0055] Step S3: The scaled-down guide rail model 5 and the scaled-down maglev train model 6 are rotated to the target yaw angle and locked by the overall yaw turntable 4. Under windless conditions, the same suspension gap setting value, guide gap setting value, suspension control parameters and scaled-down secondary suspension parameters as in the windy test are maintained. After the suspension state is stable, the output of the built-in six-component force measurement unit 602, air gap sensor 502, dynamic response sensor 607, current detection module and real-time controller are collected simultaneously as the windless baseline data under the target yaw angle.

[0056] Step S4: Start the wind tunnel and adjust the wind speed to the target wind speed. Through the suspension control and data acquisition unit 608, synchronously acquire the six-component load signal output by the built-in six-component force measurement unit 602, the vertical suspension gap signal and / or lateral guide gap signal output by the air gap sensor 502, the linear acceleration signal, angular velocity signal, attitude angle signal and / or vehicle body relative displacement signal output by the dynamic response sensor 607, and the actual driving current and suspension control command of the lateral guide electromagnet 605 and / or vertical suspension electromagnet 606 according to a unified sampling clock. In this embodiment, the suspension control command includes at least one of the following: electromagnet current command, voltage command or power drive control command generated by the real-time controller based on the deviation between the air gap measurement value and the target air gap value. The actual driving current is the power supply circuit current of the lateral guide electromagnet 605 and / or vertical suspension electromagnet 606 measured by the current detection module.

[0057] Step S5: Based on the windless baseline data at the target yaw angle collected in step S3 and the windy test data collected in step S4, a pre-calibrated six-component calibration matrix is ​​used to couple and correct each measurement channel of the built-in six-component force measurement unit 602, and the windy output and windless output under the same yaw angle, the same suspension gap set value, and the same suspension control parameters are differentially analyzed; based on the mass, center of gravity position, and moment of inertia of the aerodynamic outer shell 601, as well as the linear acceleration and angular acceleration detected or calculated by the dynamic response sensor 607, the differential six-component load is inertially corrected to obtain the aerodynamic force and aerodynamic torque of the scaled-down maglev train model 6; based on the vertical suspension gap signal, the lateral guide gap signal, the dynamic response signal, the actual driving current of the electromagnet, and the suspension control command, the suspension gap response, vibration response, attitude response, and electromagnetic control response of the scaled-down maglev train model 6 are obtained.

[0058] Step S6: Change at least one of the target wind speed, target yaw angle, suspension control parameters, and stiffness or damping parameters of the scaled-down secondary suspension 604 to conduct the test for the next target operating condition; when only the target wind speed is changed, keep the yaw angle, suspension clearance setting, suspension control parameters, and scaled-down secondary suspension parameters unchanged, and repeat steps S4 and S5; when the target yaw angle, suspension control parameters, or scaled-down secondary suspension parameters are changed, re-establish the preset suspension state under the new target operating condition and collect the corresponding windless baseline data, and then repeat steps S4 and S5 to obtain aerodynamic load and dynamic response data under different operating conditions.

[0059] In a preferred embodiment of the present invention, in step S5, a pre-calibrated six-component calibration matrix is ​​used to couple and correct the output of each measurement channel of the built-in six-component force measurement unit 602. The wind-driven output after coupling and correction is then compared with the windless output under the same yaw angle, the same suspension gap setting value, the same guide gap setting value, the same suspension control parameters, and the same scaled-down secondary suspension parameters. Based on the mass, center of gravity position, and moment of inertia of the aerodynamic outer shell 601, as well as the linear acceleration and angular acceleration of the aerodynamic outer shell 601, the six-component load after differentiation is inertially corrected to obtain the aerodynamic force and aerodynamic torque of the scaled-down maglev train model 6.

[0060] In a preferred embodiment of the present invention, the scaled-down guide rail model 5 and the scaled-down maglev train model 6 maintain the same installation relationship between different yaw angle tests, and the suspension gap is controlled within the allowable error range of the same set value.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art can still adjust the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Therefore, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A wind tunnel aerodynamic load and dynamic response test system for a scaled-down maglev train, characterized in that: The system includes a wind tunnel test section, an integral yaw turntable (4), a scaled-down guide rail model (5), and a scaled-down maglev train model (6). The wind tunnel test section is formed by the test section air inlet (1), the test section air outlet (2), and the test section side wall (3). The integral yaw turntable (4) is set at the bottom of the wind tunnel test section. The scaled-down guide rail model (5) is fixed on the integral yaw turntable (4). The scaled-down maglev train model (6) is set above the scaled-down guide rail model (5). The integral yaw turntable (4) is used to drive the scaled-down guide rail model (5) and the scaled-down maglev train model (6) to rotate as a whole around the vertical axis. The scaled-down guide rail model (5) includes a track beam (501) and an air gap sensor (502). The air gap sensor (502) is set on the track beam. The air gap sensor (502) includes a sensor for measuring the vertical suspension gap and / or a sensor for measuring the lateral guide gap. The scaled-down maglev train model (6) includes an aerodynamic outer shell (601), an internal six-component force measurement unit (602), a car body inertial frame (603), a scaled-down secondary suspension (604), a lateral guide electromagnet (605), a vertical levitation electromagnet (606), a dynamic response sensor (607), and a levitation control and data acquisition unit (608). The aerodynamic outer shell (601) is connected to the car body inertial frame (603) through the internal six-component force measurement unit (602). The car body inertial frame (603) is connected to the bottom of the car body through the scaled-down secondary suspension (604). The lateral guide electromagnet (605) and the vertical levitation electromagnet (606) are connected to the car body inertial frame (603) through the scaled-down secondary suspension (604). The levitation electromagnet (606) is set inside the rail-clamping hook of the scaled-down maglev train model (6) and forms a non-contact electromagnetic interaction with the guiding surface and levitation surface of the corresponding track beam (501) respectively; the levitation control and data acquisition unit (608) is connected to the air gap sensor (502), the built-in six-component force measurement unit (602), the lateral guide electromagnet (605), the vertical levitation electromagnet (606) and the dynamic response sensor (607) respectively. The levitation control and data acquisition unit (608) is used to maintain the preset levitation state and simultaneously acquire aerodynamic load, levitation gap, electromagnet current and dynamic response data.

2. The wind tunnel aerodynamic load and dynamic response test system for a scaled-down maglev train according to claim 1, characterized in that: The built-in six-component force measuring unit (602) is a single six-component balance or an equivalent six-component force measuring component composed of multiple multi-axis force sensors; The inertial frame (603) of the vehicle body is provided with a mass adjustment section and an inertia adjustment section. The mass adjustment section and the inertia adjustment section are used to adjust the total mass, center of gravity position, and roll, pitch and yaw rotational inertia of the scaled-down maglev train model (6).

3. The wind tunnel aerodynamic load and dynamic response test system for a scaled-down maglev train according to claim 2, characterized in that: The scaled-down binary suspension (604) includes at least one of a vertical elastic element, a lateral elastic element, a longitudinal elastic element, and a damping element, and the stiffness and / or damping of the scaled-down binary suspension (604) can be set by replacing the elastic element, changing the installation position, or adjusting the damping parameters.

4. The wind tunnel aerodynamic load and dynamic response test system for a scaled-down maglev train according to claim 3, characterized in that: The dynamic response sensor (607) is disposed at at least one of the pneumatic outer shell (601), the inertial frame of the vehicle body (603), and the bottom surface of the scaled-down maglev train model (6). The dynamic response sensor (607) includes at least one of an acceleration sensor, an angular velocity sensor, an attitude sensor, and a vehicle body relative displacement sensor.

5. The wind tunnel aerodynamic load and dynamic response test system for a scaled-down maglev train according to claim 4, characterized in that: The suspension control and data acquisition unit (608) includes a real-time controller, an electromagnet power drive module, a current detection module, and a synchronous data acquisition module. The current detection module is connected to the power supply circuit of the lateral guide electromagnet (605) and / or the vertical suspension electromagnet (606). The synchronous data acquisition module is used to synchronously acquire the outputs of the dynamic response sensor (607), the built-in six-component force measurement unit (602), the air gap sensor (502), and the current detection module. The real-time controller is used to receive the measurement signal from the air gap sensor (502), compare the measured gap with the target gap, and generate an electromagnet current command based on the deviation. The electromagnet power drive module supplies power to the lateral guide electromagnet (605) and the vertical suspension electromagnet (606) according to the current command to adjust the guide gap and the suspension gap in a closed loop.

6. The wind tunnel aerodynamic load and dynamic response test system for a scaled-down maglev train according to claim 5, characterized in that: The suspension control and data acquisition unit (608) has an aerodynamic load test mode and an aerodynamic-power coupling response test mode; In the aerodynamic load test mode, the suspension control and data acquisition unit (608) maintains the preset suspension gap and guide gap and acquires six-component loads; In the aerodynamic-dynamic coupling response test mode, the scaled-down secondary suspension (604) retains the motion of the inertial frame (603) of the car body relative to the scaled-down maglev train model (6), and the suspension control and data acquisition unit (608) synchronously acquires the air gap sensor (502), dynamic response sensor (607), electromagnet drive current and suspension control quantity.

7. A method for using a scaled-down maglev train wind tunnel aerodynamic load and dynamic response testing system, characterized in that, Includes the following steps: Step S1: Based on the geometric and dynamic parameters of the target maglev train and guide rail, determine the scaled-down maglev train model (6), the scaled-down guide rail model (5), the car body mass and moment of inertia, the stiffness and damping of the scaled-down secondary suspension (604), and the target value of the suspension gap. Step S2: Fix the scaled-down guide rail model (5) to the overall yaw turntable (4), start the vertical suspension electromagnet (606) and the lateral guide electromagnet (605) so that the scaled-down maglev train model (6) reaches the preset suspension state relative to the scaled-down guide rail model (5), and perform windless baseline calibration on the built-in six-component force measurement unit (602), air gap sensor (502) and dynamic response sensor (607), and record the electromagnet current baseline and suspension control quantity baseline by the suspension control and data acquisition unit (608); Step S3: Drive the scaled-down guide rail model (5) and the scaled-down maglev train model (6) to rotate to the target yaw angle and lock them by the overall yaw turntable (4), and confirm that the relative position and suspension gap of the scaled-down maglev train model (6) and the scaled-down guide rail model (5) meet the test requirements. Step S4: Start the wind tunnel and adjust the wind speed to the target wind speed. Through the suspension control and data acquisition unit (608), synchronously acquire the six-component load signal output by the built-in six-component force measurement unit (602), the vertical suspension gap signal and / or lateral guide gap signal output by the air gap sensor (502), the linear acceleration signal, angular velocity signal, attitude angle signal and / or vehicle body relative displacement signal output by the dynamic response sensor (607), and the actual driving current and suspension control command of the lateral guide electromagnet (605) and / or vertical suspension electromagnet (606) according to a unified sampling clock. Step S5: Based on the no-wind baseline data at the target yaw angle collected in step S3 and the windy test data collected in step S4, the pre-calibrated six-component calibration matrix is ​​used to couple and correct each measurement channel of the built-in six-component force measurement unit (602), and the windy output and no-wind output under the same yaw angle, the same suspension gap setting value and the same suspension control parameters are differentially divided; based on the mass, center of gravity position and moment of inertia of the aerodynamic outer shell (601), and the linear acceleration and angular acceleration detected or calculated by the dynamic response sensor (607), the differential six-component load is inertially corrected to obtain the aerodynamic force and aerodynamic torque of the scaled-down maglev train model (6); based on the vertical suspension gap signal, the lateral guide gap signal, the dynamic response signal, the actual driving current of the electromagnet and the suspension control command, the suspension gap response, vibration response, attitude response and electromagnetic control response of the scaled-down maglev train model (6) are obtained. Step S6: Change at least one of the target wind speed, target yaw angle, suspension control parameters, and stiffness or damping parameters of the scaled-down secondary suspension (604) to conduct the test for the next target operating condition; when only the target wind speed is changed, keep the yaw angle, suspension clearance setting, suspension control parameters, and scaled-down secondary suspension parameters unchanged, and repeat steps S4 and S5; when the target yaw angle, suspension control parameters, or scaled-down secondary suspension parameters are changed, re-establish the preset suspension state under the new target operating condition and collect the corresponding windless baseline data, and then repeat steps S4 and S5 to obtain aerodynamic load and dynamic response data under different operating conditions.

8. The method of using the wind tunnel aerodynamic load and dynamic response test system for a scaled-down maglev train according to claim 7, characterized in that: In step S5, the output of each measurement channel of the built-in six-component force measurement unit (602) is coupled and corrected using a pre-calibrated six-component calibration matrix. The wind-driven output after coupling correction is differentiated from the windless output under the same yaw angle, the same suspension gap setting value, the same guide gap setting value, the same suspension control parameters, and the same scaled-down two-system suspension parameters. Based on the mass, center of gravity position, and moment of inertia of the aerodynamic outer shell (601), as well as the linear acceleration and angular acceleration of the aerodynamic outer shell (601), the six-component load after differentiation is inertially corrected to obtain the aerodynamic force and aerodynamic torque of the scaled-down maglev train model (6).

9. The method of using the wind tunnel aerodynamic load and dynamic response test system for a scaled-down maglev train according to claim 8, characterized in that: Between different yaw angle tests, the scaled-down guide rail model (5) and the scaled-down maglev train model (6) maintained the same installation relationship, and the suspension gap was controlled within the allowable error range of the same set value.

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