JP7273559B2 - Wind tunnel test system, control method and program for wind tunnel test system - Google Patents

Description

The present invention relates to a wind tunnel test system, a control method for a wind tunnel test system, and a program.

Conventionally, for example, Patent Literature 1 below relates to a wind tunnel test apparatus, in which a vehicle grounded on a movable moving belt is connected to a load measuring instrument via a suspension wire, and suspension when the vehicle is displaced in the vertical direction is disclosed. It describes converting the amount of wire pull into aerodynamic force.

JP-A-6-341920

In order to accurately reflect the conditions of the actual vehicle in the wind tunnel experiment, it is desirable to perform various measurements with the vehicle model steered on a moving belt. On the other hand, if the vehicle model can be steered on the moving belt, the vehicle model may deviate from the moving model when an abnormality occurs. For example, if the vehicle model falls from the moving belt, the vehicle model and the moving belt may be damaged.

Accordingly, the present invention has been made in view of the above problem, and an object of the present invention is to enable a vehicle model to be steered on the belt, and to control the vehicle model when the vehicle model deviates from the belt. An object of the present invention is to provide a new and improved wind tunnel test system, a control method for the wind tunnel test system, and a program capable of ensuring safety.

In order to solve the above problems, according to one aspect of the present invention, a vehicle model having wheels that are in contact with a rearward moving belt and roll as the belt moves; and a vehicle model that supports the vehicle model. and a safety device for lifting the vehicle model from the belt in a predetermined case, the vehicle model being steerable, and the safety device being configured such that the parameters relating to steering of the vehicle model are the A wind tunnel testing system is provided that lifts the vehicle model when a limit value set according to the velocity of the vehicle model relative to the belt is exceeded.

In order to solve the above problems, according to another aspect of the present invention, there are provided a vehicle model having wheels that are in contact with a rearward moving belt and that roll as the belt moves; A support for supporting the vehicle model, a safety device for lifting the vehicle model from the belt in a predetermined case, a camera for photographing a reference point installed in front of the vehicle model, and an image of the reference point photographed by the camera. and a control device for controlling the vehicle model based on the above, wherein the control device calculates a lateral deviation amount of the vehicle model from an image of the reference point captured by the camera, and calculates the lateral deviation amount and the vehicle model. A wind tunnel testing system is provided for controlling the steering of the vehicle model based on the velocity relative to the belt.

Further, the safety device has a wire connected to the vehicle model from above and an actuator, and lifts the vehicle model by pulling the wire upward according to the operation of the actuator. can be

In order to solve the above problems, according to another aspect of the present invention, there are provided a vehicle model having wheels that are in contact with a rearward moving belt and that roll as the belt moves; and a safety device for lifting the vehicle model from the belt in a given case, the safety device comprising three wires connected to the vehicle model from above and an actuator. and pulling the three wires upward in response to actuation of the actuators to lift the vehicle model.

Further, in order to solve the above problems, according to another aspect of the present invention, a steering wheel having wheels that are grounded on a belt moving backward and roll along with the movement of the belt is provided and can be steered. determining whether or not a steering parameter of the vehicle model exceeds a limit value in the vehicle model; and moving the vehicle model from the belt if the steering parameter of the vehicle model exceeds the limit value. and a lifting step.

Further, in order to solve the above problems, according to another aspect of the present invention, a steering wheel having wheels that are grounded on a belt moving backward and roll along with the movement of the belt is provided and can be steered. Means for determining whether or not a steering parameter of the vehicle model exceeds a limit value in the vehicle model, and lifting the vehicle model from the belt when the steering parameter of the vehicle model exceeds the limit value. A program is provided for causing a computer to function as a means.

As described above, according to the present invention, the vehicle model can be steered on the belt, and safety can be ensured when the vehicle model deviates from the belt.

1 is a schematic diagram showing the configuration of a system according to one embodiment of the present invention; FIG. FIG. 5 is a schematic diagram showing a state in which the vehicle scale model is raised by the safety device 500; 1 is a perspective view showing a vehicle scale model; FIG. FIG. 4 is a schematic diagram showing an area of an image captured by a camera and positions of reference LEDs in the area; FIG. 4 is a schematic diagram showing an area of an image captured by a camera and positions of reference LEDs in the area; FIG. 2 is a schematic diagram showing a configuration of a control device that steers front wheels and controls a safety device and its surroundings. It is a flowchart which shows the process which activates a safety device. FIG. 4 is a schematic diagram showing a controllable steering angle limit value α0; FIG. 5 is a schematic diagram for explaining a method of calculating a steering angle θ from a lateral deviation amount y; FIG. 3 is a schematic diagram showing a configuration for calculating a steering angle θ by PID calculation based on a wire angle β and a vehicle speed v;

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

First, referring to FIG. 1, the configuration of a wind tunnel testing system 1000 according to one embodiment of the present invention will be described. This embodiment relates to a system for evaluating dynamic characteristics in a moving belt wind tunnel using a vehicle scale model. As shown in FIG. 1, this wind tunnel test system 1000 comprises a vehicle scale model 100, a moving belt 200, rollers 300 and 310, a wire 400, a safety device 500, and a reference LED 600.

The vehicle scale model 100 has a front wheel 110 and a rear wheel 120 that are grounded on a moving belt 200 and roll according to the movement of the moving belt 200 toward the rear of the vehicle. Front wheels 110 are steerable on moving belts 200 . More specifically, the front wheels 110 can be steered by a tie rod and a steering rack on which a steering actuator 112 for transmitting steering force is mounted.

In the wind tunnel test system 1000 of the present embodiment, steering control is performed on the moving belt 200 instead of the method of fixing and supporting the vehicle scale model 100 above the moving belt 200 used in a general scale wind tunnel. , the vehicle scale model 100 is held on the moving belt 200 .

Front wheels 110 and rear wheels 120 do not themselves generate driving force. Therefore, the wire 400 supports the vehicle scale model 100 from the front in order to prevent the vehicle scale model 100 from being swept backward when the moving belt 200 moves.

Safety device 500 includes wires 510 for raising vehicle scale model 100 . When there is a possibility that vehicle scale model 100 deviates from moving belt 200, vehicle scale model 100 is raised by pulling wire 510 in the direction of arrow A1.

The vehicle scale model 100 also includes a wheel speed sensor 130 that detects the wheel speed of the rear wheels 120, the steering actuator 112 described above, and a camera 140 that captures the reference LED 600 provided in front of the vehicle scale model 100. I have it.

FIG. 2 is a schematic diagram showing a state in which the vehicle scale model 100 is raised by the safety device 500. As shown in FIG. The lower part of FIG. 2 shows the configuration of the safety device 500 . The safety device 500 has an actuator 520 . Actuator 520 drives member 530 to which wire 510 is connected in the direction of arrow A2, so that the wire is pulled in the direction of arrow A1, and vehicle scale model 100 rises.

FIG. 3 is a perspective view showing the vehicle scale model 100. As shown in FIG. In the example shown in FIG. 3 , wires 510 are connected to two locations on the front of vehicle scale model 100 and wire 510 is connected to one location on the rear of vehicle scale model 100 . Three points of the vehicle scale model 100 are simultaneously lifted upward by the wires 510, and the vehicle scale model 1000 is lifted from the moving belt 200 while maintaining the plane. The number of wires 510 and the arrangement of wires 510 for raising vehicle scale model 100 are not limited to the example in FIG.

As described above, front wheels 110 are steerable on moving belt 200 . In this embodiment, the camera 140 included in the vehicle scale model 100 photographs the reference LED 600, measures the amount of displacement of the reference LED 600 within the imaging area, and steers the front wheels 110 based on the amount of displacement.

4A and 4B are schematic diagrams showing an area 142 of an image captured by the camera 140 and the position of the reference LED 600 within the area 142. FIG. FIG. 4A shows the state at the time of initial setting, in which the reference LED 600 is positioned in the center of the area 142. FIG. The position of the reference LED 600 shown in FIG. 4A becomes the reference point.

FIG. 4B shows a state in which the position of the reference LED 600 is shifted with respect to FIG. 4A. In FIG. 4B, the amount of deviation from the reference point is determined from the number of pixels. In FIG. 4B, the position of the reference LED 600 is displaced by two pixels with respect to FIG. 4A. For example, in the case of 720 dpi, the displacement amount for one pixel is measured as 0.353 mm. Note that the deviation amount for one pixel can be appropriately determined in consideration of the specifications of the optical system of the camera 140 and the specifications of the imaging device.

FIG. 5 is a schematic diagram showing a configuration of a control device 700 for steering the front wheels 110 and controlling the safety device 500 and its surroundings. The control device 700 includes a binarization signal processing unit 710 that binarizes the image data captured by the camera 140, and a lateral displacement amount calculation unit 720 that calculates the lateral displacement amount based on the binarized image data. configured as follows. The control device 700 also includes a vehicle speed acquisition unit 730 that acquires the vehicle speed from the wheel speed detected by the wheel speed sensor 130, a steering amount calculation unit 740 that calculates the steering amount based on the lateral deviation amount and the wheel speed, and a steering amount calculation unit 740. and an actuator control unit 750 that controls the steering actuator 112 or the actuator 520 of the safety device 500 based on the above. Note that the vehicle speed acquisition unit 730 may acquire the vehicle speed from the speed of the moving belt 200 . Each component of the control device 700 can be configured by a circuit (hardware) or a central processing unit such as a CPU and a program (software) for making it function.

As shown in FIG. 5, normally, the steering actuator 112 that steers the front wheels 110 is controlled based on the steering amount calculated by the steering amount calculator 740 . Accordingly, wind tunnel measurement can be performed without the vehicle scale model 100 deviating from the moving belt 200 .

On the other hand, in the event of an abnormality, etc., the amount of steering of the front wheels 110 increases, and there is a possibility that the vehicle scale model 100 will deviate from the moving belt 200 . In such a case, actuator 520 of safety device 500 is operated to pull wire 510 in the direction of arrow A1 as shown in FIG. 2, thereby raising vehicle scale model 100. FIG. As a result, the vehicle scale model 100 is not in contact with the moving belt 200, and the vehicle scale model 100 can be safely lifted while the vehicle is running, and the wind tunnel test system 1000 can be stopped.

FIG. 6 is a flow chart showing the process of activating the safety device 500. As shown in FIG. First, in step S10, the wheel speed acquisition section 730 acquires the wheel speed. In the next step S12, the controllable steering angle limit value α0 is calculated using the threshold determination graph shown in FIG.

The threshold judgment graph shown in FIG. 7 shows the characteristics of the controllable steering angle limit value α0 (vertical axis) according to the vehicle speed (horizontal axis). As shown in FIG. 7, the higher the vehicle speed, the lower the controllable steering angle limit value α0. The threshold judgment graph shown in FIG. 7 can be obtained by simulating the convergence of steering with respect to the amount of lateral deviation by simulating the motion of the vehicle while maintaining the center using the camera 140, and identifying the steering limit. Since there is a limit to the angle that can be converged and steered for each speed, the amount of deviation from the reference point is constantly detected during running, and the safety device 500 is activated when the amount of deviation exceeds the threshold.

In the next step S<b>14 , the lateral deviation amount calculator 720 calculates the lateral deviation amount y of the reference LED 600 from the image captured by the camera 140 .

In the next step S16, the steering amount calculator 740 calculates a steering angle θ for returning the position of the reference LED 600 to the initial position shown in FIG. 4A from the lateral deviation amount y. FIG. 8 is a schematic diagram for explaining a method of calculating the steering angle θ from the lateral displacement amount y, and shows a state in which the vehicle scale model 100 and the reference LED 600 are viewed from above. As shown in FIG. 8, the wire angle β is calculated from the following equation (1) from the lateral displacement amount y calculated from the image captured by the camera 140 and the length of the wire 400 (wire length L).
β=sin ⁻¹ (y/L) (1)

Steering control for converging the wire angle β to 0 [deg] is performed by the steering actuator 112 mounted on the vehicle scale model 100 . Since the wire angle β changes in linear proportion by controlling the turning angle δ of the steering actuator 112, the following equation (2) holds. λ is a specific constant of the steering actuator 112 .
δ*λ=β (2)

The steering angle θ is calculated by the following formula (3). Here, Ks is a coefficient of steering angle and turning angle, and Kv is a coefficient of vehicle speed. Also, v is the vehicle speed.
θ=Ks(δ*λ)*Kv(1/V) (3)

When the wire angle β changes due to steering, the steering angle corresponding to that angle is set and the control information is updated. Lateral displacement may be calculated by an acceleration sensor as auxiliary information. FIG. 9 is a schematic diagram showing a configuration for calculating the steering angle θ by PID calculation based on the wire angle β and the vehicle speed v. As shown in FIG. In FIG. 9, an image processing unit 760 is a block that calculates the wire angle β based on the image captured by the camera 140, and includes the above-described binarized signal processing unit 710, lateral slip amount calculation unit 720, and steering amount calculation unit 740. corresponds to a part of the configuration of A block surrounded by a dashed line, which includes the PID controller 1 and the PID controller 2, corresponds to the steering amount calculator 740. FIG.

As described above, in step S16, the steering angle θ for returning the position of the reference LED 600 to the initial position shown in FIG. 4A can be calculated based on the wire angle β and the vehicle speed. In the next step S18, it is determined whether or not the steering angle θ obtained in step S16 is larger than the steering angle limit value α0 obtained in step S12. Proceed to S20.

At step S20, the safety device 500 is activated. As a result, the vehicle scale model 100 is lifted upward as shown in FIG. After step S20, the process ends.

As described above, according to the process of FIG. 6, when the vehicle scale model 100 is laterally displaced, the steering angle θ for returning the position of the reference LED 600 to the initial position shown in FIG. 4A is equal to the steering angle limit value α0. If it is greater than , the safety device 500 is activated. This reliably prevents the vehicle scale model 100 from deviating from the moving belt 200 and falling from the moving belt 200 when the steering angle θ is greater than the limit value α0 determined according to the vehicle speed. can.

As described above, according to the present embodiment, when there is a possibility that the vehicle scale model 100 deviates from the moving belt 200, the safety device 500 is operated to lift the vehicle model 100. FIG. Therefore, it is possible to reliably prevent a situation such as the vehicle scale model 100 falling from the moving belt 200 .

Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs can conceive of various modifications or modifications within the scope of the technical idea described in the claims. It is understood that these also naturally belong to the technical scope of the present invention.

100 vehicle scale model 110 front wheel 120 rear wheel 140 camera 200 moving belt 400 wire 500 safety device 510 wire 520 actuator 700 control device

Claims (6)

a vehicle model having wheels that are grounded on a rearward moving belt and that roll as the belt moves;
a support for supporting the vehicle model;
a safety device for lifting the vehicle model off the belt in predetermined cases;
with
the vehicle model is enabled to steer;
A wind tunnel experiment, wherein the safety device lifts the vehicle model when a steering parameter of the vehicle model exceeds a limit value set according to the speed of the vehicle model relative to the belt. system. a vehicle model having wheels that are grounded on a rearward moving belt and that roll as the belt moves;
a support for supporting the vehicle model;
a safety device for lifting the vehicle model off the belt in predetermined cases;
a camera that captures a reference point installed in front of the vehicle model;
a control device for controlling the vehicle model based on an image of the reference point captured by the camera;
with
The control device calculates a lateral deviation amount of the vehicle model from the image of the reference point captured by the camera, and controls steering of the vehicle model based on the lateral deviation amount and the speed of the vehicle model relative to the belt. A wind tunnel test system characterized by : The safety device has a wire connected to the vehicle model from above, and an actuator, and lifts the vehicle model by pulling the wire upward according to the operation of the actuator. , The wind tunnel test system according to claim 1 or 2. a vehicle model having wheels that are grounded on a rearward moving belt and that roll as the belt moves;
a support for supporting the vehicle model;
a safety device for lifting the vehicle model off the belt in predetermined cases;
with
The safety device has three wires connected to the vehicle model from above and an actuator, and pulls the three wires upward in accordance with the operation of the actuator to move the vehicle model A wind tunnel test system characterized by lifting . In a steerable vehicle model that is grounded on a belt that moves backward and has wheels that roll as the belt moves, it is determined whether or not a parameter related to steering of the vehicle model exceeds a limit value. a step of determining;
lifting the vehicle model from the belt when a steering parameter of the vehicle model exceeds the limit value;
A control method for a wind tunnel test system, comprising: In a steerable vehicle model that is grounded on a belt that moves backward and has wheels that roll as the belt moves, it is determined whether or not a parameter related to steering of the vehicle model exceeds a limit value. a means of determining
means for lifting the vehicle model from the belt when a steering parameter of the vehicle model exceeds the limit value;
A program that allows a computer to function as a

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