JPH07218525A - Ultrasonic transceiver type anemometer - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide an ultrasonic transmitter / receiver type anemometer configured to reduce the number of ultrasonic sensors and to simplify the circuit configuration. [Structure] The anemometer is provided with a pair of ultrasonic sensors 2 and 3 in the X and Y directions on the bottom or ceiling of the vehicle 1. Separation distance Ly of the first ultrasonic sensor 2 (first ultrasonic transmitter 4
And the distance between the first ultrasonic receiver 5) and the separation distance Lx of the second ultrasonic sensor 3 (the distance between the second ultrasonic transmitter 7 and the second ultrasonic receiver 8). Shortened (Ly
<Lx). When the reception signals from the first ultrasonic receiver 5 and the second ultrasonic receiver 8 come in, the counter 15 outputs a count value (elapsed time after the transmission signal is output) to the CPU 16 each time the reception signal comes in. Then, the CPU 16 uses the counter 1
The airspeed in the Y direction and the wind speed in the X direction are calculated on the basis of the count value integrated in 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic wave transmitter / receiver type anemometer, and more particularly to an ultrasonic wave transmitter / receiver type anemometer configured to process a signal in the X direction and a signal in the Y direction by a common receiving circuit. .

[0002]

2. Description of the Related Art For example, in an automobile, when a cross wind is received while traveling at high speed on a highway, for example, the vehicle moves laterally despite holding the steering wheel in a straight direction. It may happen. Especially when passing through a tunnel at high speed, even if there is no crosswind in the tunnel, a strong crosswind may be received as soon as it leaves the tunnel.

Therefore, in an automobile, an ultrasonic wave transmission / reception system is used which calculates the wind speed by detecting the time difference until the ultrasonic wave transmitted from the ultrasonic wave transmitter is received by the ultrasonic wave receiver under the influence of the wind speed. An anemometer is provided. As an anemometer of this type, for example, there is a device disclosed in Japanese Utility Model Laid-Open No. 4-127573.

In the anemometer of this publication, an ultrasonic transmitter is installed at the center of a cross-shaped support, and four ultrasonic receivers are cross-shaped so as to face each other in the front-rear, left-right (X, Y) directions. It is provided at each tip portion of the support extending to the. Further, in the anemometer of this publication, an airspeed is detected by a pair of ultrasonic receivers arranged in the traveling direction (front-back direction), and a pair of ultrasonic receivers arranged in the lateral direction (left-right direction) orthogonal to the traveling direction. The ultrasonic receiver is configured to detect the wind speed in the lateral direction, and the counter A for the traveling direction (counts the time from the transmission of the ultrasonic signal in the traveling direction to the reception thereof), the counter for the lateral direction. The signals from B (counting the time from the transmission of the ultrasonic signal in the lateral direction to the reception) are respectively supplied to the first arithmetic circuit for calculating the airspeed and the second arithmetic circuit for calculating the wind speed. It is being supplied.

[0005]

However, in the anemometer of the above publication, four ultrasonic wave receivers are provided, and the time from the transmission of an ultrasonic wave signal to the reception thereof, the air speed, and the wind speed. A counter A for the traveling direction, a counter B for the lateral direction, a first arithmetic circuit for calculating the airspeed, and a second arithmetic circuit for calculating the wind speed are required for individually calculating Is complicated, the number of parts is increased accordingly, there is a problem that it takes extra labor in the manufacturing process and it is difficult to keep the manufacturing cost low.

In view of the above problems, it is an object of the present invention to simplify the circuit configuration of an ultrasonic transmission / reception type anemometer.

[0007]

According to the present invention, there is provided a first ultrasonic transmitter for transmitting an ultrasonic signal and a first ultrasonic transmitter for receiving the ultrasonic signal transmitted from the first ultrasonic transmitter. A first ultrasonic sensor having an acoustic wave receiver; a second ultrasonic transmitter arranged to transmit an ultrasonic signal in a direction different from the transmission direction of the first ultrasonic transmitter; A second ultrasonic sensor having a second ultrasonic receiver for receiving an ultrasonic signal transmitted from a second ultrasonic transmitter; and the first ultrasonic sensor.
Common receiving circuit for alternately processing the signals received by the ultrasonic receiver and the second ultrasonic receiver, the received signal from the receiving circuit and the first ultrasonic transmitter or the second ultrasonic receiver. A calculation means for calculating the wind speed in each direction based on the phase difference from the transmission signal transmitted from the ultrasonic wave transmitter, and between the first ultrasonic wave transmitter and the first ultrasonic wave receiver. And a second distance between the second ultrasonic transmitter and the second ultrasonic receiver is different.

[0008]

A first distance between the first ultrasonic transmitter and the first ultrasonic receiver and a second distance between the second ultrasonic transmitter and the second ultrasonic receiver. By making the distance different,
Since there is a time difference between the reception signals supplied from the first ultrasonic sensor and the second ultrasonic sensor and the wind speeds in the X and Y directions can be detected, the reception signal can be processed by one receiving circuit. Therefore, the circuit configuration can be simplified.

[0009]

1 to 4 show an embodiment of an ultrasonic transmission / reception type anemometer according to the present invention.

In each of the drawings, the anemometer is generally provided with a pair of ultrasonic sensors 2 and 3 on the bottom or ceiling of the vehicle 1 in the X and Y directions. The first ultrasonic sensor 2 includes a first ultrasonic transmitter 4 arranged in front of the vehicle 1 and a first ultrasonic receiver arranged rearward of the first ultrasonic transmitter 4. It consists of 5. Therefore, the ultrasonic signal 6 transmitted from the first ultrasonic transmitter 4 is transmitted rearward along the Y direction, which is the traveling direction of the vehicle 1.

The second ultrasonic sensor 3 comprises a second ultrasonic transmitter 7 arranged on the left side of the vehicle 1 and a second ultrasonic receiver 8 arranged on the right side of the vehicle 1. And consists of. Therefore, the ultrasonic signal 9 transmitted from the second ultrasonic transmitter 7 is transmitted to the right along the X direction orthogonal to the traveling direction of the vehicle 1.

The ultrasonic transmission distances (inter-sensor distances) of the pair of ultrasonic sensors 2 and 3 are not the same, and the ultrasonic transmission distance in the X direction is longer than the ultrasonic transmission distance in the Y direction. A first ultrasonic transmitter 4, a first ultrasonic receiver 5, a second ultrasonic transmitter 7, and a second ultrasonic receiver 8 are arranged. That is, the separation distance Ly between the first ultrasonic transmitter 4 and the first ultrasonic receiver 5 is larger than the separation distance Lx between the second ultrasonic transmitter 7 and the second ultrasonic receiver 8. It is getting shorter (Ly <Lx).

Therefore, since the interval between the second ultrasonic transmitter 7 and the second ultrasonic receiver 8 is set long, the ultrasonic signal 9 transmitted from the second ultrasonic transmitter 7 is that much. The time when the crosswind is affected becomes longer, and the wind speed of the crosswind can be detected more accurately than when Ly = Lx.

Reference numeral 10 denotes a transmission circuit, which is connected in parallel with the first ultrasonic transmitter 4 and the second ultrasonic transmitter 7 via a distributor 11. Therefore, when a burst-shaped transmission signal (burst signal) is output from the transmission circuit 10, the ultrasonic signals 6 and 9 are simultaneously transmitted from the first ultrasonic transmitter 4 and the second ultrasonic transmitter 7. . As shown in FIG. 3, the transmission signal is output for a predetermined time T ₁ and is output intermittently at a constant cycle T ₂ .

The first ultrasonic wave receiver 5 and the second ultrasonic wave receiver 8 are ultrasonic signals 6, 9 transmitted simultaneously from the first ultrasonic wave transmitter 4 and the second ultrasonic wave transmitter 7. When receiving, the reception signals 13 and 14 are output.

Reference numeral 12 is a receiving circuit, which is the first ultrasonic receiver 5
And the second ultrasonic receiver 8 are connected in parallel,
The reception signals 13 and 14 from the ultrasonic receiver 5 and the second ultrasonic receiver 8 are shaped into pulse waves.

A counter 15 is connected to the transmission circuit 10 and the reception circuit 12, and counts the time from the transmission signal output from the transmission circuit 10 to the reception signal output from the reception circuit 12. In addition, this counter 15
When a transmission signal comes in, the counter clears the count value up to that point and counts the time based on the new transmission signal. Also, the counter 15 outputs a count value (elapsed time after the transmission signal is output) to the CPU 16 each time a reception signal comes in.

The CPU 16 uses the counter 1 as described later.
The airspeed in the Y direction and the wind speed in the X direction are calculated on the basis of the count value accumulated by 5, and the calculation results are displayed (not shown) or the engine control circuit (not shown) of the vehicle 1.
And output to.

In this embodiment, as described above, the separation distance Ly between the first ultrasonic transmitter 4 and the first ultrasonic receiver 5 is Ly.
However, since it is shorter than the distance Lx between the second ultrasonic transmitter 7 and the second ultrasonic receiver 8 (Ly <Lx), the ultrasonic signal 6 in the Y direction is received, and then X Directional ultrasonic signals 9 are received. Therefore, the reception signal 13 from the first ultrasonic receiver 5 comes into the reception circuit 12 first, and then the reception signal 14 from the second ultrasonic receiver 8 arrives.
Comes in. Further, since the ultrasonic signals 6 and 9 pass through the intermediate positions with a time difference due to the difference in the above-mentioned separation distance, it is possible to prevent the ultrasonic signals from interfering with each other at the intermediate positions.

The CPU 16 executes the processing shown in FIG. 4 while the vehicle 1 is traveling.

In FIG. 4, the CPU 16 checks in step S1 (hereinafter, "step" is omitted) whether or not a fixed time (cycle T ₂ ) has passed since the last ultrasonic signal transmission, and the fixed time is determined. After elapses, the process proceeds to S2, and the transmission circuit 10 causes the first ultrasonic transmitter 4 and the second ultrasonic transmitter 7 to output a transmission signal (burst signal). As a result, the first ultrasonic transmitter 4 and the second ultrasonic transmitter 7 simultaneously transmit the ultrasonic signals 6 and 9.

At the same time, the transmission signal is also output to the counter 15, and the counter 15 starts counting (clocking) by supplying the transmission signal.

In next step S3, it is checked whether or not the first ultrasonic receiver 5 has received the ultrasonic signal 6 transmitted from the first ultrasonic transmitter 4. When the first ultrasonic wave receiver 5 receives the ultrasonic wave signal 6, the first ultrasonic wave receiver 5 receives the received signal.
2, output to the counter 15.

Therefore, when the first ultrasonic receiver 5 receives the ultrasonic signal 6, the CPU 16 proceeds to S4 and calculates the wind speed v _{y in the} Y direction based on the count value t ₁ accumulated by the counter 15. And outputs the calculation result.

In the next step S5, it is checked whether the second ultrasonic receiver 8 has received the ultrasonic signal 9 transmitted from the second ultrasonic transmitter 7. When the second ultrasonic wave receiver 8 receives the ultrasonic wave signal 9, the second ultrasonic wave receiver 8 receives the received signal.
2, output to the counter 15.

Therefore, when the second ultrasonic receiver 8 receives the ultrasonic signal 9, the CPU 16 proceeds to S6 and calculates the wind speed v _{x in the} X direction based on the count value t ₂ accumulated by the counter 15. And outputs the calculation result.

When the process of S6 is completed, the process returns to S1 and the processes of S1 to S6 are repeated.

As described above, the received signals from the first ultrasonic receiver 5 and the second ultrasonic receiver 8 are supplied to the counter 15 via one receiving circuit 12. That is, the transmission circuit 10, the reception circuit 12, the counter 15, and the CPU 16 are
Since it is not necessary to separately provide each wind speed detection direction, it is simplified. As a result, the number of parts can be reduced, labor can be saved in the manufacturing process, and the manufacturing cost can be kept low.

Now, the conditions for installing the pair of ultrasonic sensors 2 and 3 will be described. The separation distance Ly between the first ultrasonic transmitter 4 and the first ultrasonic receiver 5 and the separation distance Lx between the second ultrasonic transmitter 7 and the second ultrasonic receiver 8 are as follows. To be decided.

T ₁ = Ly / (C ± v _y ) ... (1) t ₂ = L _x / (C ± v _x ) ... (2) However, at t _{1, the} ultrasonic signal 6 in the Y direction is received. , T ₂ is the time until the ultrasonic signal 9 in the X direction is received, C is the sound velocity, v _x is the wind velocity in the X direction of the crosswind, and v _y is the wind velocity in the Y direction of the crosswind.

Then, the above L _x , Ly, v _x , v _y are
Assuming that t ₁ <t ₂ , it is determined that the following equation is satisfied.

T ₁ + T ₁ <t ₂ (3) (However, for v _x and v _y , the wind speed range that can be realized is estimated in advance from the dynamic range.) To _{satisfy the} above equation (3), For example, the dynamic range is v _x = ± 30 m / s (crosswind), v _y = ± 50 m /
FIGS. 5 and 6 show the results of calculating the arrival time until the ultrasonic signals 6 and 9 are received with the fixed values of s (vehicle speed 180 km / h) and L _x , Ly, and T ₁ as parameters. Incidentally, FIG.
FIG. 6 is a diagram showing the relationship between the ultrasonic arrival time and the distance between the ultrasonic sensors when the Y direction ultrasonic signal is transmitted forward. FIG. 6 shows the Y direction ultrasonic signal directed backward. It is a diagram which shows the relationship of the ultrasonic arrival time at the time of transmitting, and the separation distance of an ultrasonic sensor.

In FIG. 5, when T ₁ is 1 ms, 2 ms, 3 ms and Ly = 0.6 m, the above (3)
To satisfy the formula, at point A, T ₁ = 1 ms, Ly =
It is set to 0.6 m or more and L _x = 0.8 m or less. Point B,
When T ₁ = 2 ms, Ly = 0.6 m or more, L _x = 1.15 m
Set as follows. Ly = 0.6 at point C and T ₁ = 2 ms
It is set to m or more and L _x = 1.5 m or less.

In all the above-mentioned points A to C, v _{x in} the leftward direction
= 30 m / s (+30 m / s) to the right, v _x = 3
Since 0 m / s (−30 m / s) is smaller, v _x = 30 m / s in the right direction is taken as the crosswind wind speed.

Further, in FIG. 6, T _{1 is set} to 1 ms, 2 ms, 3
In addition to ms, and Ly = 0.4 m, in order to satisfy the above equation (3), at point D, when T ₁ = 1 ms, L
Set y = 0.4 m or more and L _x = 0.75 m or less. E
Point, Ly = 0.4 m or more when T ₁ = 2 ms, L _x = 1.0
Set to 5 m or less. At point F, T ₁ = 2 ms, Ly =
It is set to 0.4 m or more and L _x = 1.4 m or less.

Therefore, the distance L _x in the X direction and the distance Li in the Y direction are approximately L _x : Ly = 0.8 to
It may be set to be 1.4: 0.3 to 0.7.

As described above, the transmission signals (burst signals) are set as shown in FIG. 3 by setting the respective separation distances L _x and Ly of the ultrasonic sensors 2 and 3 so as to satisfy the above expression (3). It is possible to prevent the signals 6 and 9 and the received signals 13 and 14 from interfering with each other, and it is possible to detect the accurate wind speed.

FIG. 7 shows a modification of the present invention.

In the above embodiment, as shown in FIG.
However, the present invention is not limited to this, and as shown in FIG. 7, the first ultrasonic transmitter 4 is provided in the front part of the vehicle 1, and the first ultrasonic receiver 5 is provided in the vehicle 1. It may be provided in the rear part. In this case, the separation distance Ly between the first ultrasonic transmitter 4 and the first ultrasonic receiver 5 is greater than the separation distance Lx between the second ultrasonic transmitter 7 and the second ultrasonic receiver 8. Also becomes longer (Ly> Lx).

The Ly and Lx are determined as follows.

T ₁ = L _x / (C ± v _x ) ... (4) t ₂ = L _y / (C ± v _y ) ... (5) Then, L _x , Ly, v _x , and v _y are Assuming that t ₁ <t ₂ , it is determined to satisfy the above equation (3).

In the modification shown in FIG. 7, the distance Lx between the second ultrasonic transmitter 7 and the second ultrasonic receiver 8 is set to the same length as in the above embodiment, The distance Ly between the first ultrasonic transmitter 4 and the first ultrasonic receiver 5 is extended. Therefore, the interval between the first ultrasonic transmitter 4 and the first ultrasonic receiver 5 is set to be longer than that in the above-described embodiment, and the wind velocity of the crosswind is detected more accurately as in the above-described embodiment. In addition to that, the ultrasonic signal 6 transmitted from the first ultrasonic transmitter 4 is affected by the wind in the traveling direction for a longer time, and the airspeed is more accurate than when Ly = Lx. Can be detected.

[0043]

As described above, according to the present invention, the first distance between the first ultrasonic transmitter and the first ultrasonic receiver, the second distance between the second ultrasonic transmitter and the second ultrasonic transmitter, Since the second distance between the first ultrasonic sensor and the second ultrasonic sensor is different, there is a time difference between the reception signals supplied from the first ultrasonic sensor and the second ultrasonic sensor, which reduces the number of sensors. Can be reduced,
The reception signal can be processed by one reception circuit, and the circuit configuration can be simplified. Therefore, the number of parts is reduced by that amount, labor saving can be achieved in the manufacturing process, and the manufacturing cost can be kept low.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of an ultrasonic transmission / reception type anemometer according to the present invention.

FIG. 2 is a plan view showing an arrangement of ultrasonic sensors.

FIG. 3 is a waveform diagram of a transmission signal and a reception signal.

FIG. 4 is a flowchart illustrating a process executed by a CPU.

FIG. 5 is a diagram showing a relationship between an ultrasonic wave arrival time and an ultrasonic sensor separation distance at an air speed of 50 m / s.

FIG. 6 is a diagram showing a relationship between an ultrasonic wave arrival time and an ultrasonic sensor separation distance when an ultrasonic signal in the Y direction is transmitted forward with respect to FIG. 6;

FIG. 7 is a plan view of a modified example of the present invention.

[Description of Reference Signs] 1 vehicle 2 first ultrasonic sensor 3 second ultrasonic sensor 4 first ultrasonic transmitter 5 first ultrasonic receiver 6, 9 transmission signal 7 second ultrasonic transmitter 8 Second ultrasonic receiver 10 Transmission circuit 12 Reception circuit 13, 14 Reception signal 15 Counter 16 CPU

Claims (1)

[Claims] 1. A first ultrasonic wave transmitter for transmitting an ultrasonic wave signal, and a first ultrasonic wave receiver for receiving the ultrasonic wave signal transmitted from the first ultrasonic wave transmitter. An ultrasonic sensor, a second ultrasonic transmitter arranged to transmit an ultrasonic signal in a direction different from the transmission direction of the first ultrasonic transmitter, and the second ultrasonic transmitter A second ultrasonic sensor having a second ultrasonic receiver for receiving the transmitted ultrasonic signal, and alternating signals received by the first ultrasonic receiver and the second ultrasonic receiver. Common receiving circuit to be processed in the above, and the wind speed in each direction based on the phase difference between the receiving signal from the receiving circuit and the transmitting signal transmitted from the first ultrasonic transmitter or the second ultrasonic transmitter. Calculating means for calculating the distance between the first ultrasonic transmitter and the first ultrasonic receiver. A first distance, the second ultrasonic transmitter and the ultrasonic transceiver anemometer of which is characterized in that the made different second distance between the second ultrasonic receiver.