WO2012014319A1

WO2012014319A1 - Wind speed measurement device

Info

Publication number: WO2012014319A1
Application number: PCT/JP2010/062920
Authority: WO
Inventors: 泰輝児玉; 隆二郎藤田; 岳彦塩田
Original assignee: パイオニア株式会社
Priority date: 2010-07-30
Filing date: 2010-07-30
Publication date: 2012-02-02
Also published as: JPWO2012014319A1; JP5489135B2

Abstract

Disclosed is a low-cost wind speed measurement device capable of preventing accuracy loss. The disclosed wind speed measurement device is provided with a sound wave detection means (1A) which, attached to a moving body such as a bicycle (B), generates sound waves from an airflow (e.g. the wind) and detects said sound waves, an extraction means (band-pass filter) (14) which extracts a specific frequency component from the sound waves detected by the sound wave detection means (1A), and a wind speed calculation means (S7) which calculates the wind speed on the basis of the specific frequency component extracted by the extraction means (14).

Description

Wind speed measuring device

The present invention relates to a wind speed measuring device.

Due to the recent increase in health consciousness, outdoor sports such as walking, running, and cycling are widely used as hobbies. Some persons who perform such outdoor sports use a device that measures a movement speed, a movement distance, or calorie consumption. That is, there is a person who confirms the movement distance and calorie consumption in real time as the progress, a person who confirms the movement speed in real time as the exercise content, and a person who confirms or records the movement distance and calorie consumption as a result. As described above, a person who performs outdoor sports enjoys outdoor sports by using a predetermined device to set and measure his / her own indicators.

By the way, outdoor sports such as walking are performed in the natural environment, so the influence of the wind is great. For example, when driving a bicycle, the air resistance increases when the head wind increases (the wind speed of the head wind increases). The speed is reduced. Therefore, when the driver's exercise state (for example, the number of rotations of the pedal) is used as an indicator of traveling, the traveling speed decreases when the headwind blows. In this case, even if the cause of the decrease in speed is in the wind, the driver misunderstands that the traveling speed has decreased because the degree of fatigue has increased, and the driver cannot travel comfortably. In the case of a bicycle, when it exceeds 30 km / h, most of the resistance to running becomes air resistance.

Also, when the travel speed is used as an index of travel, if the air resistance also changes with the change of wind, the driver adjusts the number of rotations of the pedal so as to keep the travel speed constant. Therefore, even if the vehicle travels on the same course, a difference occurs in the work performed by the driver according to the strength of the wind. In the case of strong headwinds, in order to keep the running speed constant, work that exceeds the capacity for air resistance may be required. In this case, the driver cannot feel uncomfortable or humiliated because the running speed cannot be kept constant, as well as physical fatigue.

Thus, the air resistance caused by the wind affects the driver both mentally and physically, so it can be said that it is an important indicator for driving. The distance traveled by the mobile person relative to the air (atmosphere) (hereinafter referred to as “the travel distance relative to the air”), which is related to the air resistance, is considered to be a new indicator for outdoor sports. This “movement distance with respect to the air” can be calculated by integrating the “relative speed of the mobile person (sport performer) with respect to the air (atmosphere)”.

The wind speed measuring device described in Patent Document 1 (hereinafter referred to as “prior art 1”) includes a wind direction sensor and a cylindrical air guide tube, and a sensing unit constituting the wind direction sensor is disposed in the air guide tube. Has been. Prior art 1 measures the axial component of the introduction pipe of the wind speed by letting the wind flow through the wind guide pipe.

A wind speed measuring device (hereinafter referred to as “prior art 2”) described in Patent Document 2 includes a first vortex body and a second vortex body that generate Karman vortices, and microphones attached to the vortex bodies. And a pressure conduit for transmitting the pressure fluctuation of the Karman vortex attached to each vortex body to the microphone. Prior art 2 measures the wind speed by causing a wind to collide with the vortex and generating a Karman vortex.

The wind speed measuring device described in Patent Document 3 (hereinafter referred to as “prior art 3”) is converted by an air flow / acoustic conversion unit that converts an air flow blown out from an opening into sound, and an air flow / acoustic conversion unit. A microphone that collects sound and converts it into an electrical signal. Prior art 3 measures the wind speed (air volume) by bringing the air stream (wind) into contact with the air stream / acoustic converter.

Japanese Unexamined Patent Publication No. 2000-162229 JP 2004-317191 A Japanese Patent Laid-Open No. 06-194374

Prior art 1 is generally bi-directional and can measure the wind speed in a specific direction such as the traveling direction, but is expensive because it includes a wind speed sensor. In that respect, since the prior art 2 and the prior art 3 are equipped with a microphone, they are cheaper than the prior art 1, but also detect various sounds generated around cars, trains, creatures, etc. The accuracy of the measured value will decrease.

An object of the present invention is to provide an inexpensive wind speed measuring device that can suppress a decrease in accuracy in view of the above background.

In order to solve the above problems, a wind speed measuring device according to the present invention generates sound waves from an air flow attached to a moving body and detects sound waves, and is detected by the sound wave detection means. It has an extraction means for extracting a specific frequency component from a sound wave, and a wind speed calculation means for calculating a wind speed based on the specific frequency component extracted by the extraction means.

(A) is a side view of a bicycle to which a cycle computer having a wind speed measuring device is attached, and (b) is an enlarged view of a portion to which the cycle computer is attached in the bicycle of FIG. 1 (a). (A) is a front view of the main part of the cycle computer, (b) is a rear view of the main part of the cycle computer, (c) is a longitudinal sectional view of the main part of the cycle computer, and (d) is a diagram of FIG. It is AA sectional drawing. It is an electrical block diagram of a cycle computer. It is a block diagram of a cycle computer. It is a flowchart showing the main process by a control apparatus. It is a flowchart showing the sound pressure level signal input interruption process by a control apparatus. It is a flowchart showing the mode change interruption process by a control apparatus. It is a flowchart showing the timer interruption process by a control apparatus.

(First embodiment)
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1A is an external view showing a state in which a cycle computer S in which the wind speed measuring device 1 of the present invention is incorporated and integrated with a device having other functions is attached to a bicycle B. FIG. That is, in the present embodiment, the wind speed measuring device 1 of the present invention is not configured independently, but constitutes a part of the cycle computer S.

FIG. 2 is a diagram illustrating an example of a structural configuration of the cycle computer S including the wind speed measuring device 1 according to the first embodiment of the present invention. The cycle computer S includes a wind speed measuring device 1 that measures a wind speed relative to the bicycle B, a display device 2 that displays predetermined information that is set in advance, an input device 3 that inputs predetermined information by an operation, and a predetermined external device. A communication device 4 for communicating with (not shown), a sensor group 5 for measuring predetermined information, a control device 6 constituting a part of each device and responsible for main control of each device, these devices And a main body 7 for accommodating and integrating a part of the sensor group 5.

The main body 7 is made of synthetic resin such as plastic and has a substantially flat plate shape. An attachment portion 7 </ b> A for attaching to the bicycle B is provided on one surface of the main body 7. The attachment portion 7A is made of a synthetic resin such as plastic and has a structure that is fixed to the handle B1 in a state where the handle B1 of the bicycle B is gripped. On the surface (hereinafter referred to as “front surface”) opposite to the surface on which the mounting portion 7A is provided (hereinafter referred to as “rear surface”), the display unit 21 on which predetermined information is actually displayed and the operable operation A part 31 is provided. The display unit 21 constitutes a part of the display device 2 and is realized by, for example, a liquid crystal panel. On the other hand, the input unit 31 constitutes a part of the input device 3 and is realized by, for example, a button. When the cycle computer S is attached to the handle B1 of the bicycle B by the attachment portion 7A, the back surface of the main body 7 faces the ground, and the front surface of the main body 7 faces the atmosphere. Therefore, the driver can easily visually recognize the display unit 21 and the input unit 31.

In the present embodiment, the front surface and the back surface of the main body 7 are formed in parallel, and the shape and size thereof are the same, and an approximately oval shape or an approximately rhombus shape with different diagonal lengths is used. Presented. In a state where the cycle computer S is appropriately attached to the handle B1 of the bicycle B, the major axis direction of this surface coincides with the moving direction of the bicycle. The display unit 21 and the input unit 31 are juxtaposed in the long axis direction. When the cycle computer S is properly attached to the handle B1 of the bicycle B, the display unit 21 is located closer to the front of the bicycle B. In addition, the input unit is located on the rear side of the bicycle B.

The wind speed measuring device 1 is provided between the mounting portion 7A, the display portion 21, and the input portion 31. The wind speed measuring device 1 includes a flow path 11 through which an air flow such as wind flows, a sound wave sensor 12 that detects sound waves (vibration), and a detection port that generates sound waves (vibration) from the air flow upstream of the sound wave sensor 12. 13 is provided.

The flow passage 11 is configured by a hole that vertically cuts the main body 7 in the long axis direction of the main body 7. That is, the hole constituting the flow passage 11 penetrates from one end surface of the main body 7 to the other end surface. And the part of the hole currently formed in the front end (traveling direction side) end surface of the bicycle B constitutes the inflow port 11A of the flow passage 11, and is formed in the other rear end (reverse direction side) end surface. The hole portion constitutes the outlet 11 </ b> B of the flow passage 11. Accordingly, an air flow such as wind moving from the front and rear of the bicycle B to the bicycle B flows into the flow passage 11 from the inflow port 11A, and flows out from the outflow port 11B through the flow passage 11.

The flow passage 11 is surrounded by the main body 7 in the entire circumferential direction with respect to the central axis C1 (length direction). Therefore, the inflow path 11 is shielded from an air flow such as wind moving from the measuring method of the bicycle B (direction orthogonal to the central axis C1) to the bicycle B.

A cross section perpendicular to the central axis C1 of the flow passage 11 (hereinafter, abbreviated as “cross section of the flow passage 11”) has a substantially rectangular shape, and gradually expands from the front side to the rear side of the bicycle B. Yes. That is, the outlet 11B is wider than the inlet 11A. However, in the present embodiment, the height of the flow passage 11 (the length in the direction orthogonal to the front surface and the back surface of the main body 7) is constant, and the width of the flow passage 11 (the length of the front surface and the back surface in the minor axis direction). Only) is enlarged from the front side toward the rear side. The central axis C1 of the flow passage 11 is parallel to the surface of the main body 7 and the like.

In Embodiment 1, the cross section of the flow passage 11 has a rectangular shape, but the cross sectional shape of the flow passage 11 is not particularly limited. Further, only the length in the short axis direction such as the surface is enlarged from the front side toward the rear side, but the cross section of the flow passage 11 only needs to be enlarged in that direction, and the mode of expansion is particularly limited. Not. The central axis C1 of the flow passage 11 is a straight line parallel to the surface or the like, but may be a straight line inclined to the surface or a curved line.

A sound wave sensor 12 is provided at the central portion of the main body 7 in the long axis direction. That is, the sonic sensor 12 is disposed between the surface of the main body 7 and the flow passage 11. The sound wave sensor 12 is not particularly limited in its structure and shape as long as it can detect sound waves. In the present embodiment, a MEMS microphone packaged in a flat plate shape is used as the acoustic wave sensor 12.

A detection port 13 is formed from a hole wall of the flow passage 11 to a mouth portion (not shown, hereinafter referred to as “sound port”) for collecting sound waves of the sound wave sensor 12, and the flow passage 11 and the sound port of the sound wave sensor 12 are detected. It communicates with the mouth 13 (spatial connection). Therefore, when an air flow such as wind relatively moving from the front and rear of the bicycle B toward the bicycle B flows into the flow passage 11 from the inflow port 11A and passes through the detection port 13, turbulent flow (so-called "" Wind noise ”) is generated, and moves in the detection port 13 toward the sound wave sensor 12. As a result, the sound wave sensor 12 detects turbulent flow generated by an air flow such as wind as sound waves (so-called “wind noise”). The sound wave sensor 12 outputs sound pressure data obtained by converting the detected sound wave into an electric signal to the control device 6 described later. The shape of the detection port 13 is not particularly limited, but if the detection port 13 has a columnar shape, attenuation of sound waves (vibration) due to bending loss can be suppressed, and therefore the detection port 13 has a columnar shape. Is desirable.

Here, the following is experimentally or empirically known as the behavior of the air flow when a hollow structure having an inlet / outlet opened at both ends is arranged in the atmosphere. When the cross section of the hollow portion of the hollow structure is enlarged along the direction of the air flow (hereinafter referred to as “case 1”), the flow velocity of the air flow increases toward the outlet of the hollow structure. On the other hand, when the hollow portion of the hollow structure is contracted along the direction of the air flow (hereinafter referred to as “case 2”), the flow velocity of the air flow decreases toward the outlet of the hollow structure.

Here, even in the vicinity of the entrance / exit of the hollow portion of the hollow structure, it is in the atmosphere immediately before the entrance and immediately after the exit, and is under the same atmospheric pressure. Therefore, in both the case 1 and the case 2, the air pressure immediately before the airflow flows into the hollow portion of the hollow structure is the same as the air pressure immediately after flowing out of the hollow portion of the hollow structure. It becomes. That is, the tendency of the flow velocity of the air flow in the hollow portion differs depending on whether the cross section of the hollow portion expands or contracts along the direction of the air flow.

From this tendency, for example, when the cross section orthogonal to the center line C1 of the flow path 11 expands from the front side to the rear side of the bicycle B as in the present embodiment, the directivity of the acoustic wave sensor 12 is The direction from the rear of the bicycle B toward the bicycle B (the traveling direction of the bicycle B) is relatively stronger in the direction from the front of the bicycle B toward the bicycle B (retracting direction). The reason for this will be described below.

In the example of the hollow structure described above, in any case (case 1 and case 2), the pressure immediately after the exit of the cavity is the same as the atmospheric pressure, so the pressure in the cavity is generally directed toward the exit. Asymptotically approaches atmospheric pressure and converges to atmospheric pressure at the exit. However, since the inflow amount of air is different, the flow velocity of the air flow immediately before the outlet is different. In case 1, the air that has flowed toward the outlet gradually increases in volume. However, since the atmospheric pressure is equal to the outside in the vicinity of the outlet, the air flow is discharged from the outlet while the flow velocity gradually increases. In the case 2, the air that has flowed toward the outlet gradually decreases in volume. However, since the atmospheric pressure is equal to the outside in the vicinity of the outlet, the air flow is discharged from the outlet while the flow velocity gradually decreases.

When the tendency of the behavior of the air flow in the hollow portion is applied to the air flow flowing through the flow passage 11 in the present embodiment, the inlet 11A is narrower than the outlet 11B. The velocity of the moving airflow at the detection port 13 is faster when the airflow flows into the flow passage 11 from the front of the bicycle B. That is, the directivity of the sound wave sensor 12 is strong in the direction from the front of the bicycle B toward the bicycle B.

The wind speed measuring device 1 measures the wind speed based on the sound wave detected by the sound wave sensor 12. As will be described later, the wind speed is measured by the control device 6 including a substrate on which a CPU 61 and a memory 62 described later are mounted. The control device 6 is accommodated in the main body 7 (not shown) and is electrically connected to the sound wave sensor 12 by a predetermined cable. Moreover, in this Embodiment, the display part 21 and the input part 31 are also electrically connected to the control apparatus 6, and the control apparatus 6 also performs predetermined display control and input control. That is, the control device 6 constitutes part of the wind speed measuring device 1, the display device 2, and the input device 3.

FIG. 3 is a block diagram showing an electrical configuration of the cycle computer S including the wind speed measuring device 1 according to the first embodiment of the present invention.

The display device 2 includes a display unit 21 on which preset or selected information is displayed, and a display control circuit 22 that controls display on the display unit 21 according to an instruction from the CPU 61 described later. The display unit 21 and the display control circuit 22 are electrically connected by a predetermined bus.

The input device 3 includes an operable input unit 31 for inputting predetermined information, and an input control circuit 32 that controls input in the input unit 31 according to an instruction from the CPU 61 described later. The input unit 31 and the input control circuit 32 are electrically connected by a predetermined bus. By operating the input unit 31, it is possible to start / end data measurement and data calculation, select an environment mode to be described later, and input predetermined information such as a user ID, height, and weight. When the input unit 31 is operated, an input signal corresponding to the button type and operation mode is sent from the input unit 31 to an input control circuit (or a data input unit to be described later), and then the input signal is sent to the control device 6. Is output. In the present embodiment, the input unit 31 is composed of three buttons arranged in parallel in the minor axis direction of the surface of the main body 7. In addition to the buttons, the input unit 31 includes a cross key, a trackball, and a joystick. It is also possible to use a pointing device such as Further, the structure of the input unit 31 may be a touch panel so as to be integrated with the display unit 21.

The communication device 4 includes a communication interface (I / F) 41 for transmitting and receiving various data to and from an external device (not shown) such as a mobile terminal such as a mobile phone, and the communication interface 41 according to instructions from the CPU 61 described later. And a communication control circuit 42 for performing control. The communication interface 41 and the communication control circuit 42 are electrically connected by a predetermined bus. In response to an instruction from the CPU 61, the communication control circuit 42 outputs various data stored in the memory 62 to a predetermined external device (not shown) via the communication interface 41, and from the predetermined external device. Are input via the communication interface 41. Note that the communication interface 41 is realized by various antennas in the case of a wireless communication method, and is realized by a predetermined type of outlet or the like in the case of a wired communication method.

As shown in FIG. 3, the sensor group 5 of the cycle computer S includes a speed sensor 51, a cadence sensor 52, an acceleration sensor 53, a power sensor 54, a tilt sensor 55, a temperature sensor 56, a humidity sensor 57, an atmospheric pressure sensor 58, and a GPS sensor. 59 and the sound wave sensor 12 of the wind speed measuring device 1. Each sensor is appropriately attached to the inside or the outside of the cycle computer S according to each use. Each sensor is electrically connected to an A / D converter and a serial I / F mounted on the control device 6 by a wireless communication method or a wired communication method.

The speed sensor 51 is a device that measures the absolute speed of the bicycle B. The speed sensor 51 includes, for example, a magnet fixed to a spoke of the wheel of the bicycle B and a magnet detector attached to a chain stay or the like, and measures the number of times the magnet detector detects the magnet per unit time. Then, the speed data obtained by converting the measured value into an electric signal is output to the control device 6. Then, the CPU 61 of the control device 6 calculates the speed of the bicycle B by multiplying this number by the outer periphery of the tire.

The cadence sensor 52 is a device that measures the rotation speed (cadence) of the pedal of the bicycle B per unit time. The cadence sensor 52 includes, for example, a magnet attached to a crank and a magnet detector attached to a chain stay or the like. The cadence sensor 52 measures the number of times the magnet detector detects a magnet per unit time, and uses the measured value as an electrical value. The cadence data converted into a signal is output to the control device 6. Then, the CPU 61 of the control device 6 calculates cadence.

The acceleration sensor 53 is composed of, for example, a MEMS element, measures the acceleration of the bicycle B, and outputs acceleration data obtained by converting the measurement value into an electric signal to the control device 6. When the acceleration data is switched between positive and negative, it is possible to infer road surface conditions such as uneven road surface or soft soil. Furthermore, this estimation result can be added to a map and displayed on a display unit comprising a monitor.

The power sensor 54 is a device that measures the output of the bicycle B built in the rear wheel hub or the like of the bicycle B, and outputs the power data obtained by converting the measured value into an electric signal to the control device 6. Is something. A general power meter can measure the force applied to the sprocket. The force can be used as a criterion for evaluating the ability of the driver, and can also be used as an index for a training menu.

The tilt sensor 55 measures the tilt of the bicycle B with respect to the ground (horizontal plane), and outputs tilt data obtained by converting the measured value into an electric signal to the control device 6. For example, the control device 6 calculates the average inclination of the travel route on which the bicycle B traveled for a certain time. The temperature sensor 56 measures the temperature around the bicycle B (for example, the temperature at a stopped position, the temperature during running, etc.), and outputs temperature data obtained by converting the measured value to an electrical signal to the control device 6. . The humidity sensor 57 measures the humidity around the bicycle B (for example, humidity at a stopped position, humidity during running, etc.), and outputs humidity data obtained by converting the measured value to an electrical signal to the control device 6. . Further, the atmospheric pressure sensor 58 measures the atmospheric pressure around the bicycle B, and outputs the atmospheric pressure data obtained by converting the measured value into an electric signal to the control device 6. For example, the control device 6 calculates the altitude at which the bicycle B is located from the atmospheric pressure data.

The GPS sensor 59 is composed of a GPS chip antenna (not shown), and is incorporated into a predetermined positioning system such as a satellite, whereby the current time is acquired simultaneously with the position information of the bicycle B. The GPS sensor 59 receives a signal transmitted from the satellite and transmits it to the control device 6.

The configuration of these sensor groups 5 is an example. Therefore, the information measured and acquired by a certain sensor is only required to be finally acquired, and can be calculated and acquired from the measured values measured by other sensors. For example, without using the inclination sensor 55, the distance traveled at a certain time is calculated by the GPS sensor 59 or the like, the height difference at the certain time required for the movement is calculated from the altitude information calculated by the atmospheric pressure sensor 58, and the distance and altitude It is also possible to calculate the average slope from the difference (elevation difference). Moreover, it may replace with the atmospheric | air pressure sensor 58, the information regarding an altitude may be acquired with the GPS sensor 59, and the three-dimensional map information which has altitude information may be used as map information.

The control device 6 includes an A / D converter that converts electric signals output from various sensors into digital signals, a serial I / F, and a CPU 61 that controls the data and a memory 62 that stores data indicating various types of information. It has an I / F 63 that is a gathering, an RTC 64 that keeps track of the current time, and a crystal oscillator, and has an oscillation circuit 65 that serves as a signal for performing timer interrupt processing to be described later. The control device 6 is connected to the display control circuit 22, the input control circuit 32, and the communication control circuit 42 through a bus.

The memory 62 is realized by an internal storage device such as a flash memory, a RAM, a ROM, a hard disk drive, or a non-volatile external memory such as a USB memory or a flash memory card. The memory 62 temporarily or permanently stores information acquired by the sensor group 5 of the cycle computer S, calculation results calculated by the CPU 61, and the like. In the cycle computer S, additional information such as map information can be stored in the memory 62, a bicycle map can be created in association with the acquired / calculated data, and displayed on the display unit 21.

The band pass filter 14 constitutes the wind speed measuring device 1 and is interposed between the sound wave sensor 12 and the A / D converter. In the present embodiment, the bandpass filter 14 is a bandpass filter using an operational amplifier, and passes only a frequency band of 1 to 4 kHz. In general, the frequency of engine sounds (sounds generated by running) of automobiles and motorcycles is distributed to 1 kHz or less, and the frequency of insect voices such as cicada calls is distributed to 4 kHz or more. In this way, even if a sound wave generated by an unnecessary engine such as an automobile that is not a measurement target or a bug is detected by the sound wave sensor 12, it is removed by the bandpass filter 14. As a result, it is possible to suppress a decrease in the accuracy of the wind speed measured by the wind speed measuring device 1.

FIG. 4 is a block diagram showing a controllable (or functional) configuration of the cycle computer S including the wind speed measuring device 1 according to the first embodiment of the present invention. The cycle computer S includes a travel information acquisition unit S1, a driver / bicycle information acquisition unit S2, an environmental information acquisition unit S3, a sound pressure level calculation unit S4, an environmental mode setting unit 5, an abnormal value removal unit 6, a wind speed calculation unit S7, And a wind speed data output unit S8.

The travel information acquisition unit S1 has a function of acquiring information data related to bicycle travel (hereinafter referred to as “travel information data”). The travel information acquisition unit S1 is a sensor that measures travel information of the bicycle B such as the sound wave sensor 12, the speed sensor 51, the cadence sensor 52, the acceleration sensor 53, the power sensor 54, and the GPS sensor 59, and these sensors. It is comprised by the control apparatus 6 etc. which calculate driving information based on the measured driving information and the predetermined data previously memorize | stored in the memory 62. FIG. The predetermined data stored in the memory 62 includes data stored in advance in the ROM or data acquired by the input device 3 or the communication device 4 and stored in the RAM.

The driver / bicycle information acquisition unit S2 has a function of acquiring information data on the driver and the bicycle body (hereinafter referred to as “driver information data”). For example, the driver / information acquisition unit S2 detects an input target item related to the driver and the bicycle body selected by operating the input unit 31, and recognizes that the received data is related to the input target item. The control device 6 that sets the input mode that is the period, and information such as the driver input by operating the input unit 31 during the input mode setting is detected, and the information is converted into an electrical signal and output to the control device 6. It consists of an input device 2 and the like.

The environment information acquisition unit S3 has a function of acquiring information data related to the external environment around the bicycle B (hereinafter referred to as “environment information data”). The sensor group 5 includes sensors for measuring environmental information of the inclination sensor 55, the temperature sensor 56, the humidity sensor 57, and the atmospheric pressure sensor 58.

The sound pressure level calculation unit S4 is configured by the control device 6, and performs predetermined calculation processing using predetermined data acquired by the sensor group 5 or the like, so that the first sample time (in the present embodiment, 1) to calculate the effective value of the sound pressure level.

The environment mode setting unit S5 includes the control device 6 and has a function of internally setting an environment mode selected by operating the input unit 31. The “environment mode” is a classification of the external environment, and in this embodiment, includes “town mode”, “coast mode”, and “mountain mode”. An abnormality determination value, which will be described later, is set differently for each environmental mode.

The abnormal value removing unit S6 is configured by the control device 6 and is abnormal among the effective values of the sound pressure level calculated by the sound pressure level calculating unit S4 based on the abnormality determination value set for each environmental mode. Has a function of detecting and deleting. As described above, the detection target of the sound wave sensor 12 is a sound wave that is generated when an air flow that relatively moves from the front of the bicycle B toward the bicycle passes through the detection port 13. In addition to this sound wave, various sound waves (corresponding to sounds for human hearing) are generated around the traveling bicycle B. Since the sound wave sensor 12 may detect sound waves other than the sound wave generated by the detection port 13, these sound waves become noise for the wind speed measuring device 1 and the cycle computer S.

As described above, noise that can be generated is also removed by the band-pass filter 14, but there are various sources of sound waves that become noise, and depending on the type of the source, noise that belongs to the passband of the band-pass filter 14 is also present. There is (for example, a horn sound). The generation source varies depending on the external environment. For example, in the city, car engine sounds and horn sounds frequently occur. On the coast, wave sounds, bird sounds, ship sounds and horn sounds frequently occur. In mountains, insect sounds. Is occurring frequently. And each sound has a different loudness. Therefore, by providing an abnormal value determination value according to the external environment and removing sound pressure level data exceeding the abnormal value determination value, the accuracy of the wind speed measuring device 1 is improved.

The wind speed calculation unit S7 includes the control device 6, and performs a predetermined calculation process using the effective value of the sound pressure level calculated by the sound pressure level calculation unit S5 and not removed by the abnormal value removal unit S7. By performing, the average value (representative value) of the wind speed in the second sample time (10 seconds in the present embodiment) is calculated.

The wind speed data output unit S8 has a function of displaying a predetermined measurement value or calculated value, or input information input by an operation by the input unit 31, and is configured by the display device 2. The wind speed data output unit S8 has a function of transmitting predetermined data to an external device (not shown), and includes the communication device 4 and the like.

Next, a process for measuring the sound pressure level and a process for measuring the relative wind speed with respect to the bicycle B will be described with reference to FIGS.

When the power source of the cycle computer S is turned on and power is supplied to the CPU 61, a system reset occurs in the CPU 61, and the CPU 61 performs the following main processing.

First, in step S101, the CPU 61 performs an initialization process. In this process, the CPU 61 reads the activation program from the ROM in the memory 62, clears the RAM in the memory 62, and moves the process to step S102.

In step S102, the CPU 61 sets the first sample time (1 second) to the first timer, and in step S103, sets the second sample time (10 seconds) to the second timer. As will be described later, the first sample time refers to a period during which sound pressure data output by the sound wave sensor 12 and digitized by an A / D converter or the like via the bandpass filter 14 is sampled. The first timer is a device that measures the first sampling time. On the other hand, the second sample time is a period serving as a reference for calculating an average value per unit time of the sound pressure level subjected to effective value conversion, as will be described later. The second timer is a device that measures the remaining time of the second sampling time. The first timer and the second timer are subtracted every 4 ms in step S201 described later.

In step S104, the CPU 61 permits a predetermined interrupt process. Hereinafter, the predetermined interrupt process will be described.

The sound wave detection interrupt process will be described with reference to FIG. In step S201, the CPU 61 determines whether or not the electrical signal (sound pressure data) output from the sound wave sensor 12 is input. If the CPU 61 determines that the sound pressure data is not input, the CPU 61 ends the interruption process. If the CPU 61 determines that the sound pressure data is input, the CPU 61 converts the sound pressure data into the sound pressure data stored in the RAM of the memory 62 in step S203. The data is stored in the storage area, and the interrupt process is terminated.

The mode change interrupt process of the control device 6 will be described with reference to FIG. In step S301, the CPU 61 determines whether or not an electrical signal (mode data) indicating the type of environmental mode output from the input control device 3 has been input. If the CPU 61 determines that mode data has not been input, the CPU 61 terminates the mode change interrupt process. If the CPU 61 determines that mode data has been input, in step S302, the mode associated with the type of mode indicated by the mode data. The flag is set in the mode flag storage area of the RAM of the memory 62, and the mode change interrupt process ends.

In the present embodiment, three modes, “city mode”, “coast mode”, and “mountain mode”, are set as modes, and flags corresponding to each mode have a 2-byte configuration. “01H”, “02H”, and “03H” are set. When the process is performed, if the mode flag has already been set in the mode flag storage area, the existing mode flag is overwritten with the new mode flag.

The timer interrupt process of the control device 6 will be described with reference to FIG. The generation circuit 66 provided in the control device 6 generates a clock pulse every predetermined period (4 milliseconds), thereby executing a timer interrupt process described below.

First, in step S401, the CPU 61 performs time control processing for updating the first timer and the second timer. By this process, the values set in both timers are subtracted by 4 (ms).

In step S402, the CPU 61 determines whether or not the first sampling time has elapsed, that is, whether or not the first timer is “0”. If the CPU 61 determines that the first sampling time has not elapsed, it moves the process to step S407, and if it determines that the first sampling time has elapsed, it moves the process to step S403.

In step S403, the CPU 61 sets the first sampling time (1 second) to the first timer, and in step S404 converts the sound pressure data stored in the sound pressure data storage area of the RAM into an effective value. The sound pressure level is calculated, and the sound pressure level that has undergone effective value conversion in step S405 is stored in a predetermined area of the RAM as sound pressure level effective value data. Here, when the CPU 61 stores the sound pressure level effective value data in the RAM, the CPU 61 correlates the elapsed time (0 to 10 seconds) in the second sampling time with the electrical signal sent from the sound wave sensor 12 as a time. It is digitized (digitized) using two elements: progress and sound pressure level effective value data.

In step S406, the CPU 61 clears the sound pressure data storage area and moves the process to step S407. In the present embodiment, the sound pressure data is completely erased every time the first sampling time elapses. However, the sound pressure data may be transferred to another storage device or another storage area of the RAM and stored continuously. Good. Further, even if the first sampling time elapses, the data stored at the first sampling time is not erased, and the next new first sampling time is distinguished from the data stored at the previous first sampling time. As possible, the sound pressure data may be stored subsequent to the data stored at the previous first sampling time.

In step S407, the CPU 61 determines whether or not the second sampling time has elapsed, that is, whether or not the second timer is “0”. If the CPU 61 determines that the second sampling time has not elapsed, the CPU 61 ends the timer interruption process. If the CPU 61 determines that the second sampling time has elapsed, the process proceeds to step S408.

In step S408, the CPU 61 sets the second sampling time (10 seconds) in the second timer. In step S409, the CPU 61 sets the environmental mode flags (01H, 02H,...) Stored in the environmental mode flag storage area in the RAM of the memory 62. Or, 03H) is confirmed to recognize the current environment mode.

In step S410, the CPU 61 detects an abnormal value from the sound pressure level effective value data stored in the RAM of the memory 62 at the second sampling time based on the environmental mode recognized in step S409. And the process proceeds to step S411. That is, the CPU 61 detects a sound pressure level effective value data stored during the second sampling time that is equal to or higher than the abnormality determination value associated with the environmental mode.

For example, in the city, many cars are running, and the sound pressure level (sound volume) of the sound wave generated around the bicycle is very high, so the abnormality determination value in the city mode corresponding to the city is the highest. Is set. On the other hand, on the coast and mountains, there are not many automobiles running compared to the city, but the sound pressure level of sound waves caused by automobiles when a bicycle passes by a car cannot be ignored. Therefore, an abnormality determination value lower than that in the city mode is set for the coast mode and the mountain mode corresponding to the coast and mountains. As described above, even if the process of simply removing the abnormal value is performed, the influence of a single and unnecessary sound wave is reduced, so that a decrease in accuracy of the wind speed measured by the wind speed measuring device 1 can be suppressed. Moreover, since the accuracy of removing the abnormal value is improved by setting the abnormality determination value according to the external environment, it is possible to further suppress a decrease in the accuracy of the wind speed measured by the wind speed measuring device 1.

In step S411, if the CPU 61 detects an abnormal value that is sound pressure level effective value data that exceeds the abnormal determination value in step S410, and determines that there is no abnormal value, the process proceeds to step S413, and there is an abnormal value. If it is determined that the sound pressure level effective value data related to the abnormal value is deleted from the sound pressure level effective value data storage area in step S412, the process proceeds to step S413.

In step S413, the CPU 61 calculates an average value of sound pressure level effective values in the second sample time. In step S414, the CPU 61 converts a predetermined sound pressure level stored in advance in the ROM of the memory 62 into a wind speed or a predetermined value. The wind speed is calculated based on the conversion formula for converting the sound pressure level to the wind speed, and the process proceeds to step S415.

In step S415, the CPU 61 displays the wind speed calculated in step S414 on the display unit 21 and stores it in the wind speed data storage area of the RAM 62 of the memory 62 as wind speed data in association with the current time that can be acquired by the RTC 64. Then, the process proceeds to step S416.

In step S416, the CPU 61 clears the sound pressure level effective value data storage area, and ends the timer interrupt process. In the present embodiment, the sound pressure level effective value data is completely deleted every time the second sampling time elapses, but it is transferred to other storage devices and other storage areas of the RAM so as to continue to be stored. It may be. In addition, even if the second sampling time has elapsed, the data stored at the second sampling time is not erased, and the next new second sampling time is distinguished from the data stored at the previous second sampling time. As can be done, the sound pressure level effective value data may be stored subsequent to the data stored in the previous second sampling time.

(Other embodiments)
In addition to the first embodiment, modifications and improvements as long as the object of the present invention can be achieved are included in the present invention. For example, the wind speed measuring device 1 is attached to the bicycle B and incorporated in the cycle computer S used for cycling. For example, the wind velocity measuring device 1 may be incorporated into a measuring device corresponding to the cycle computer S attached to the motorbike. . Even in this case, sound waves that are outside the detection target are frequently or continuously generated from the engine mounted on the motorcycle. However, for example, by detecting an ignition pulse and fuel consumption, information on sound waves by the engine is acquired, and the abnormal value can be accurately removed by using the information in the abnormal value detection processing. .

In addition, a measurement device in which the wind speed measurement device 1 is integrated can be attached to the user himself and used for running and skiing and skating. In the case of running, sound waves that are outside the detection purpose are periodically generated when landing, but by detecting the landing timing with an acceleration sensor or impact sensor, the landing timing can be used for abnormal value detection processing. An abnormal value can be accurately removed. On the other hand, in the case of skiing and skating, sound waves that are outside the detection purpose are generated when the traveling direction is changed, but changes in the traveling direction can be detected by the acceleration sensor, so the detected change in the traveling direction is abnormal. It can be used in the value detection process to remove abnormal values with high accuracy.

In the first embodiment, the wind speed measuring device 1 is incorporated in the main body 7 of the cycle computer S. However, a structure separated from the main body 7 may be used. In this case, the wind speed measuring device 1 needs to be able to communicate with the control device 2. Furthermore, in the first embodiment, the wind speed measuring device 1 (cycle computer S) displays the wind speed while the bicycle B is running, but does not have a display function and stores data such as wind speed data. The data may be output to a fixed terminal such as a personal computer installed at home or the like and displayed on the screen.

Furthermore, in the first embodiment, the wind speed measuring device 1 is attached to the handle B1 of the bicycle B. Although the directivity of the wind speed measuring device 1 is relatively strong in the direction from the front of the bicycle B to the bicycle B, the airflow moving from the rear of the bicycle B toward the bicycle B can be detected structurally. However, when the driver rides on the bicycle B, the wind speed measuring device 1 is shielded by the driver from the air flow moving from the rear of the bicycle B toward the bicycle B. Therefore, for example, a sound wave detection means 1A (flow passage 11; a flow path 11, which detects sound waves by generating sound waves from the air flow of the wind speed measuring device 1 behind the driver of the bicycle B such as a frame into which the saddle of the bicycle B is inserted. The performance of the cycle computer S can be improved by providing an equivalent to the acoustic wave sensor 12 and the detection port 13). The reason for this will be described below.

The sound wave detecting means that can communicate with the wind speed measuring device 1 is attached to the rear side of the driver of the bicycle B and the part corresponding to the inflow port 11A is directed to the rear side of the bicycle B. Suppose that In this case, the air flow (head wind) coming from the front of the bicycle B by the sound wave detection means of the wind speed measuring device 1 is accurately detected, and the air flow coming from the rear of the bicycle B by the one corresponding to the sound wave detection means is accurately obtained. Can be detected. Therefore, the cycle computer S can accurately measure not only the wind speed of the airflow that increases the load on the driver but also the wind speed of the airflow that reduces the load on the bicycle B. As a result, it is possible to accurately calculate the “distance that the moving person moves relative to the atmosphere” (hereinafter referred to as “the moving distance relative to the atmosphere”).

DESCRIPTION OF SYMBOLS 1 Wind speed measuring device 1A Sound wave detection means 2 Display apparatus 3 Input device 4 Communication apparatus 5 Sensor group 6 Control apparatus 7 Main body 7A Attachment part 11 Flow path 11A Inlet 11B Outlet 12 Sound wave sensor 13 Detection port 14 Band pass filter (extraction means) )
21 Display Unit 22 Display Control Circuit 31 Input Unit 32 Input Control Circuit 41 Communication Interface 42 Communication Control Circuit 51 Speed Sensor 52 Cadence Sensor 53 Acceleration Sensor 54 Power Sensor 55 Inclination Sensor 56 Temperature Sensor 57 Humidity Sensor 58 Air Pressure Sensor 59 GPS Sensor 61 CPU
62 Memory 63 Interface group 64 RTC
65 Oscillation circuit B Bicycle B1 Steering wheel S1 Travel information acquisition unit S2 Driver / bicycle information acquisition unit S3 Environmental information acquisition unit S4 Sound pressure level calculation unit (sound pressure calculation unit)
S5 Environment mode setting unit S6 Abnormal value removal unit (abnormal value detection unit)
S7 Wind speed calculation unit (wind speed calculation means)
S8 Wind speed data output section

Claims

A sound wave detecting means attached to the moving body, generating sound waves from the air flow, and detecting the sound waves;
Extraction means for extracting a specific frequency component from the sound wave detected by the sound wave detection means;
A wind speed measuring device comprising: wind speed calculating means for calculating a wind speed based on the specific frequency component extracted by the extracting means.
The wind speed calculating means is
A sound pressure calculator that calculates a sound pressure level based on the specific frequency component;
When the sound pressure calculating unit calculates the sound pressure level a predetermined number of times or for a predetermined time, an abnormal value for detecting an abnormal value that satisfies a preset condition from the calculated values calculated by the sound pressure calculating unit A detection unit, and
The wind speed measuring device according to claim 1, wherein when the abnormal value detecting unit detects the abnormal value, the wind speed calculating unit calculates the wind speed by removing the abnormal value.