WO2018003693A1 - Tire mounted sensor and road surface condition estimating device including same - Google Patents

Tire mounted sensor and road surface condition estimating device including same Download PDF

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Publication number
WO2018003693A1
WO2018003693A1 PCT/JP2017/023193 JP2017023193W WO2018003693A1 WO 2018003693 A1 WO2018003693 A1 WO 2018003693A1 JP 2017023193 W JP2017023193 W JP 2017023193W WO 2018003693 A1 WO2018003693 A1 WO 2018003693A1
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WO
WIPO (PCT)
Prior art keywords
road surface
tire
change
transmission
data
Prior art date
Application number
PCT/JP2017/023193
Other languages
French (fr)
Japanese (ja)
Inventor
雅士 森
高俊 関澤
良佑 神林
Original Assignee
株式会社デンソー
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2017110682A external-priority patent/JP2018009974A/en
Application filed by 株式会社デンソー filed Critical 株式会社デンソー
Priority to US16/313,069 priority Critical patent/US20190225227A1/en
Publication of WO2018003693A1 publication Critical patent/WO2018003693A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C19/00—Tyre parts or constructions not otherwise provided for
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C7/00—Tracing profiles
    • G01C7/02—Tracing profiles of land surfaces
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01W—METEOROLOGY
    • G01W1/00—Meteorology

Definitions

  • the present disclosure detects a vibration received by a tire, creates a road surface data indicating the road surface state based on the vibration data, and transmits the road surface state to the vehicle side system, and a road surface state estimation that estimates the road surface state based on the vibration data. It relates to the device.
  • a tire mount sensor is provided on the back surface of a tire tread, and vibration applied to the tire is detected by the tire mount sensor, and the detection result of the vibration is transmitted to the vehicle body system to estimate the road surface state.
  • a road surface state estimating device to perform has been proposed.
  • the road surface state is estimated based on a detection signal of a vibration detection unit provided in the tire mount sensor. Specifically, the level of the high frequency component in the detection signal of the vibration detection unit changes according to the road surface state. For this reason, the level of the high-frequency component in the detection signal of the vibration detection unit in the grounding section is defined as the road surface state when the portion corresponding to the placement position of the tire mount sensor in the tire tread is in contact with the road surface.
  • road surface data Used as road surface data.
  • road surface data is transmitted from the tire mount sensor to the vehicle body side system, and the road surface state is estimated based on the road surface data in the vehicle body side system. More specifically, an integrated voltage value obtained by integrating a high-frequency component of a detection signal indicated as a voltage value is used as road surface data.
  • a road surface friction coefficient (hereinafter referred to as road surface ⁇ ) is based on the magnitude of the integrated voltage value. Etc. are estimated.
  • An object of the present disclosure is to provide a tire mount sensor that can reduce power required for data transmission and can quickly transmit a change in a road surface state to a vehicle body side system, and a road surface state estimation device including the tire mount sensor. .
  • the tire mount sensor in one viewpoint of this indication is a tire mount sensor attached to the back of a tire, Comprising: The vibration detection part which outputs the detection signal according to the size of the vibration of a tire, The detection signal of a vibration detection part A signal processing unit that detects a road surface state from vibration data indicated by and a transmission unit that transmits road surface data representing the road surface state, and the signal processing unit responds to changes in the road surface state due to tire rotation. A transmission control unit that sets a transmission interval of road surface data and transmits the road data from the transmission unit.
  • the transmission interval can be changed, and the timing for increasing the transmission interval can be included. For this reason, it is possible to reduce the power required for data transmission at least at the timing of increasing the transmission interval, compared to the case where the transmission interval is always constant.
  • the transmission control unit detects when the road surface state has changed with the rotation of the tire and when the road surface state has not changed. At the time of change, the transmission interval is made shorter than when there is no change, and the road surface data is transmitted from the transmitter.
  • the transmission interval is made shorter than when there is no change, so that the change in the road surface condition can be quickly transmitted to the vehicle body system.
  • a vehicle danger avoidance device 100 including a road surface state estimation device will be described.
  • the vehicle risk avoidance device 100 according to the present embodiment estimates a road surface state during traveling based on vibration applied to a ground contact surface of a tire provided on each wheel of the vehicle, and also determines the risk of the vehicle based on the road surface state. Notification and vehicle motion control are performed.
  • the vehicle danger avoidance device 100 includes a tire mount sensor 1 provided on the wheel side and a vehicle body side system 2 including each part provided on the vehicle body side.
  • the vehicle body side system 2 includes a receiver 21, an electronic control device for brake control (hereinafter referred to as a brake ECU) 22, a vehicle communication device 23, a notification device 24, and the like.
  • the vehicle danger avoidance device 100 transmits data representing the road surface condition during traveling, such as data indicating the road surface ⁇ between the tire 3 and the road surface during traveling, from the tire mount sensor 1.
  • data representing the road surface condition during traveling such as data indicating the road surface ⁇ between the tire 3 and the road surface during traveling
  • ⁇ data data representing the road surface state
  • road surface data data representing the road surface state
  • the vehicle danger avoidance device 100 receives road surface data transmitted from the tire mount sensor 1 by the receiver 21 and notifies the road surface state indicated by the road surface data. 24 tells. As a result, it is possible to inform the driver of the road surface condition such as low road surface ⁇ , dry road, wet road or frozen road, and it is possible to warn the driver when the road surface is slippery. Become. Further, the vehicle risk avoidance device 100 transmits the vehicle surface state to the brake ECU 22 that performs vehicle motion control, so that vehicle motion control for avoiding danger is performed.
  • the vehicle danger avoidance device 100 transmits road surface data to the communication center 200 through the vehicle communication device 23 so that the road surface state can be mapped as described later.
  • the tire mount sensor 1 and the receiver 21 are configured as follows.
  • the tire mount sensor 1 is a tire side device provided on the tire side. As shown in FIG. 2, the tire mount sensor 1 includes an acceleration sensor 11, a temperature sensor 12, a control unit 13, an RF circuit 14, and a power source 15. As shown in FIG. 31 is provided on the back side.
  • the acceleration sensor 11 constitutes a vibration detection unit for detecting vibration applied to the tire.
  • the acceleration sensor 11 detects the acceleration as a detection signal corresponding to the vibration in the tire tangential direction indicated by the arrow X in FIG. 3 in the direction in contact with the circular orbit drawn by the tire mount sensor 1 when the tire 3 rotates.
  • the detection signal is output.
  • the acceleration sensor 11 generates, as a detection signal, an output voltage in which one of the two directions indicated by the arrow X is positive and the opposite is negative.
  • the temperature sensor 12 outputs a detection signal corresponding to the temperature, and measures the temperature of the traveling road surface by detecting the temperature at the mounting position of the tire mount sensor 1 in the tire 3.
  • the control unit 13 is a portion corresponding to a signal processing unit, and uses the detection signal of the acceleration sensor 11 as a detection signal representing vibration data in the tire tangential direction, obtains road surface data by processing the detection signal, It plays a role of transmitting it to the RF circuit 14. Specifically, the control unit 13 extracts the ground contact section of the acceleration sensor 11 when the tire 3 rotates based on the detection signal of the acceleration sensor 11, that is, the time change of the output voltage of the acceleration sensor 11. Note that the contact section here means a section in which a portion of the tread 31 of the tire 3 corresponding to the position where the acceleration sensor 11 is disposed is grounded on the road surface.
  • the portion corresponding to the location where the tire mount sensor 1 is disposed in the tread 31 of the tire 3 is the road surface. It is an agreement with the grounded section.
  • the control unit 13 Since the high frequency component included in the detection signal of the acceleration sensor 11 in the contact section represents the road surface state, the control unit 13 extracts the high frequency component from the detection signal and extracts the high frequency component as described later. Is used to detect the road surface condition such as the road surface ⁇ .
  • the control unit 13 since the temperature of the traveling road surface is measured by the temperature sensor 12, the control unit 13 detects the road surface state based on the temperature of the traveling road surface, The road surface condition obtained from the high-frequency component of the detection signal is corrected.
  • the control unit 13 when the control unit 13 detects the road surface state, the control unit 13 generates road surface data indicating the road surface state, and performs a process of transmitting the road surface data to the RF circuit 14. Thereby, road surface data is transmitted to the receiver 21 through the RF circuit 14. At this time, if road surface data is transmitted from the RF circuit 14 every time the tire 3 makes one revolution, power consumption increases. For this reason, the transmission interval is lengthened to reduce the number of transmissions. However, if the transmission interval is simply increased, the change cannot be quickly transmitted to the vehicle body side system 2 when the road surface state changes. For this reason, the transmission interval is set according to the change in the road surface condition.
  • control unit 13 is configured by a known microcomputer including a CPU, ROM, RAM, I / O, and the like, and performs the above-described processing according to a program stored in the ROM.
  • control part 13 is provided with the area extraction part 13a, the level calculation part 13b, the data generation part 13c, and the transmission control part 13d as a function part which performs those processes.
  • the section extracting unit 13a extracts the ground section by detecting the peak value of the detection signal represented by the output voltage of the acceleration sensor 11.
  • the output voltage waveform of the acceleration sensor 11 during tire rotation is, for example, the waveform shown in FIG.
  • the output voltage of the acceleration sensor 11 takes a maximum value at the start of grounding when the portion of the tread 31 corresponding to the location where the acceleration sensor 11 is disposed begins to ground as the tire 3 rotates.
  • the section extraction unit 13a detects the start of grounding at which the output voltage of the acceleration sensor 11 takes a maximum value as the timing of the first peak value. Further, as shown in FIG.
  • the voltage takes a local minimum.
  • the section extraction unit 13a detects the end of grounding when the output voltage of the acceleration sensor 11 takes a minimum value as the timing of the second peak value.
  • the reason why the output voltage of the acceleration sensor 11 takes a peak value at the above timing is as follows. That is, when the portion of the tread 31 corresponding to the location where the acceleration sensor 11 is disposed contacts with the rotation of the tire 3, the portion of the tire 3 that has been a substantially cylindrical surface is pressed in the vicinity of the acceleration sensor 11. To be flat. By receiving an impact at this time, the output voltage of the acceleration sensor 11 takes the first peak value. Further, when the portion of the tread 31 corresponding to the location where the acceleration sensor 11 is disposed moves away from the grounding surface as the tire 3 rotates, the tire 3 is released from pressing in the vicinity of the acceleration sensor 11 and is substantially flat from the plane. Return to the cylindrical shape.
  • the output voltage of the acceleration sensor 11 takes the second peak value.
  • the output voltage of the acceleration sensor 11 takes the first and second peak values at the start of grounding and at the end of grounding, respectively.
  • the sign of the output voltage is also opposite.
  • the section extraction unit 13a extracts the ground contact section of the acceleration sensor 11 by extracting the detection signal data including the timings of the first and second peak values, and the level calculation unit 13b indicates that it is in the ground contact section. To tell.
  • the section extraction unit 13a sends a detection signal to the transmission control unit 13d at this timing. As a result, the transmission control unit 13d is informed that the tire 3 has made one rotation.
  • the level calculation unit 13b when notified from the section extraction unit 13a that it is in the grounding section, calculates the level of the high-frequency component caused by the vibration of the tire 3 included in the output voltage of the acceleration sensor 11 during that period. Then, the level calculation unit 13b transmits the calculation result to the data generation unit 13c as road surface data such as ⁇ data.
  • the level of the high-frequency component is calculated as an index representing the road surface state such as the road surface ⁇ .
  • FIG. 5A shows a change in the output voltage of the acceleration sensor 11 when traveling on a high ⁇ road surface having a relatively large road surface ⁇ such as an asphalt road.
  • FIG. 5B shows the change in the output voltage of the acceleration sensor 11 when the vehicle is traveling on a low ⁇ road surface where the road surface ⁇ is relatively small to the extent corresponding to the frozen road.
  • the first and second peak values appear at the beginning and end of the contact section, that is, at the start and end of the contact of the acceleration sensor 11, regardless of the road surface ⁇ .
  • the output voltage of the acceleration sensor 11 changes due to the influence of the road surface ⁇ .
  • the road surface ⁇ is low, such as when traveling on a low ⁇ road surface
  • fine high-frequency vibration due to slip of the tire 3 is superimposed on the output voltage.
  • Such a fine high-frequency signal due to the slip of the tire 3 is not superposed when the road surface ⁇ is high, such as when traveling on a high ⁇ road surface.
  • the frequency analysis of the output voltage during the grounding section is performed for each of the cases where the road surface ⁇ is high and low, the result shown in FIG. 6 is obtained.
  • the level is high when the road surface ⁇ is high or low, but in the high frequency range of 1 kHz or higher, the level is higher when the road surface ⁇ is low than when it is high. .
  • the level of the high frequency component of the output voltage of the acceleration sensor 11 serves as an index representing the road surface state.
  • the level calculation unit 13b calculates the level of the high frequency component of the output voltage of the acceleration sensor 11 during the grounding section by the level calculation unit 13b. Therefore, by calculating the level of the high frequency component of the output voltage of the acceleration sensor 11 during the grounding section by the level calculation unit 13b, this can be converted to ⁇ data. Further, from the ⁇ data, for example, when the road surface ⁇ is low, the road surface type corresponding to the road surface ⁇ can be detected as a road surface state, such as determining that the road is frozen.
  • the level of the high frequency component can be calculated by extracting the high frequency component from the output voltage of the acceleration sensor 11 and integrating the extracted high frequency component during the grounding section.
  • the high frequency components of the frequency bands fa to fb that are assumed to change according to the road surface condition and the road surface ⁇ are extracted by filtering or the like, and the voltages of the high frequency components of the frequency bands fa to fb extracted by the frequency analysis are obtained. Integrate.
  • a capacitor (not shown) is charged. In this way, the amount of charge increases when the road surface ⁇ is low, such as when traveling on a low ⁇ road surface, rather than when the road surface ⁇ is high, such as when traveling on a high ⁇ road surface. .
  • this charge amount as the ⁇ data it is possible to estimate the road surface ⁇ such that the larger the charge amount indicated by the ⁇ data, the lower the road surface ⁇ .
  • the data generation unit 13c basically generates road surface data based on the calculation result of the level calculation unit 13b.
  • the data generation unit 13c adopts ⁇ data as it is as road surface data, obtains a road surface state such as a frozen road or an asphalt road from ⁇ data, and generates data indicating the road surface data as road surface data.
  • the temperature of the traveling road surface is measured by the temperature sensor 12.
  • the data generation unit 13c acquires the road surface temperature by inputting the detection signal of the temperature sensor 12, detects the type of the road surface from the acquired road surface temperature, or obtains from ⁇ data correction or ⁇ data. The type of road is corrected.
  • the data generation unit 13c detects that the road surface is frozen as the type of the road surface. Furthermore, the data generation unit 13c corrects the ⁇ data obtained from the high frequency component of the detection signal of the acceleration sensor 11 or the road surface type indicated by the ⁇ data when the road surface temperature detected by the temperature sensor 12 does not match. Or not adopted as a road surface condition detection result. For example, when the road surface type obtained from the high-frequency component of the detection signal of the acceleration sensor 11 is in a frozen state, and the road surface temperature detected by the temperature sensor 12 is 40 ° C., the road surface type of the frozen state is set. It is thought that there is an error in the detection result.
  • the data generation unit 13c does not adopt the result transmitted from the level calculation unit 13b as the detection result of the road surface type.
  • the road surface ⁇ indicated by the ⁇ data does not match the type of road surface obtained from the road surface temperature, for example, if the road surface ⁇ indicated by the ⁇ data is high even though the road surface temperature is detected as frozen, the ⁇ data Is corrected to a lower value than before the correction.
  • the transmission control unit 13d detects a change in road surface state based on the road surface data generated by the data generation unit 13c. Then, the transmission control unit 13d sets the transmission interval of road surface data by the RF circuit 14 according to the detected change in the road surface state, in other words, the transmission cycle, and the transmission trigger for the RF circuit 14 according to the interval. Is output. For example, when changing from dry road to wet road, conversely changing from wet road to dry road, changing from high ⁇ road to low ⁇ road, changing from low ⁇ road to high ⁇ road, etc. It is detected as a change in road surface condition. Then, a transmission trigger is output from the transmission control unit 13d when, for example, the road surface state changes according to the change in the road surface state.
  • the transmission trigger is output, for example, every one rotation or a plurality of rotations of the tire 3 according to a change in the road surface state.
  • the timing at which the transmission trigger is output at any timing of the rotation of the tire 3 is arbitrary.
  • the transmission trigger is output at the end of the grounding, that is, at the timing when the output voltage of the acceleration sensor 11 reaches the second minimum peak value. To be.
  • the transmission control unit 13d performs transmission so that road surface data is transmitted at a predetermined transmission interval as regular transmission when the road surface state indicated by the data generated by the data generation unit 13c does not change. Generate a trigger. At the time of no change, the road surface every time the tire 3 rotates a plurality of times in order to improve the battery life by reducing the power consumption or to prevent the receiver 21 from receiving data due to duplication of data transmission with other wheels.
  • the transmission interval at which data is transmitted once is used. For example, road surface data is transmitted at a rate of once every time the tire 3 rotates five times. In this case, the road surface data is transmitted to the vehicle body side system 2 every time the vehicle travels approximately 10 m.
  • the transmission control unit 13d transmits the road surface data at a predetermined transmission interval that is shorter than that when there is no change as short cycle transmission when the road surface state indicated by the data generated by the data generation unit 13c changes. Generate a transmission trigger. For example, at the time of change, the transmission interval is set so that road surface data is transmitted every time the tire 3 makes one rotation. At this time, it is good also as a transmission interval by which road surface data is transmitted only once for every rotation of the tire 3, and furthermore, the same road surface data is transmitted a plurality of times for each rotation of the tire 3. You can also.
  • the transmission control unit 13d determines that the tire is based on the detection signal.
  • the number of rotations of 3 can be detected.
  • a detection signal is sent every time the output voltage of the acceleration sensor 11 takes the first peak value from the section extraction unit 13a, or a detection signal is sent every time a ground section is extracted. Even if it makes it, it can detect the rotation speed of the tire 3 similarly.
  • the RF circuit 14 constitutes a transmission unit that transmits road surface data such as ⁇ data transmitted from the data generation unit 13c to the receiver 21, and in the case of the present embodiment, transmission from the transmission control unit 13d.
  • Road surface data is transmitted based on the trigger.
  • Communication between the RF circuit 14 and the receiver 21 can be performed by a known short-range wireless communication technique such as Bluetooth (registered trademark).
  • the timing for transmitting the road surface data is arbitrary, but as described above, in this embodiment, when the road surface condition is unchanged, the road surface data is transmitted at a rate of once every time the tire 3 rotates a plurality of times. ing. When the road surface condition changes, the transmission interval is shorter than when there is no change, and the road surface data is transmitted every time the tire 3 makes one revolution.
  • the road surface data is sent together with the unique identification information (hereinafter referred to as ID information) of the wheels provided in advance for each tire 3 provided in the vehicle.
  • ID information unique identification information
  • the position of each wheel can be specified by a well-known wheel position detection device that detects which position of the vehicle the wheel is attached to. Therefore, by transmitting road surface data together with ID information to the receiver 21, data on which wheel is detected. Can be determined.
  • the power source 15 is constituted by a battery, for example, and supplies power for driving each part of the tire mount sensor 1.
  • the receiver 21 receives the road surface data transmitted from the tire mount sensor 1, estimates the road surface state based on the road surface data, and transmits the estimated road surface state to the notification device 24, and from the notification device 24 as necessary. Inform the driver of the road surface condition. As a result, the driver tries to drive corresponding to the road surface condition, and the danger of the vehicle can be avoided.
  • the estimated road surface state may be always displayed through the notification device 24, or the estimated road surface state needs to be operated more carefully such as a wet road, a frozen road, a low ⁇ road, or the like. Only when the road surface condition is displayed, the driver may be warned.
  • the road surface state is transmitted from the receiver 21 to the ECU for executing the vehicle motion control such as the brake ECU 22, and the vehicle motion control is executed based on the transmitted road surface state. Furthermore, the receiver 21 performs a process of outputting road surface data to the vehicle communication device 23. Based on this, road surface data is sent from the vehicle communication device 23 to the communication center 200 collecting road information and the like.
  • Brake ECU22 comprises the brake control apparatus which performs various brake control. Specifically, the brake ECU 22 controls the braking force by driving the brake fluid pressure control actuator to increase or decrease the wheel cylinder pressure. The brake ECU 22 can also control the braking force of each wheel independently.
  • the braking force is controlled as vehicle motion control based on the road surface state. For example, when the transmitted road surface state indicates that the road surface is a frozen road, the brake ECU 22 weakens the braking force generated with respect to the amount of brake operation performed by the driver as compared with the case where the road surface ⁇ is large. . Thereby, wheel slip can be suppressed and it becomes possible to avoid the danger of a vehicle.
  • the vehicle communication device 23 can perform road-to-vehicle communication, and exchanges information with the communication center 200 via a communication system (not shown) installed on a road, for example.
  • the vehicle communication device 23 transmits road surface data transmitted from the receiver 21 to the communication center 200.
  • the vehicle communication device 23 can also receive more accurate road surface data from the communication center 200.
  • the notification device 24 is composed of, for example, a meter display and is used when notifying the driver of the road surface state.
  • the notification device 24 is configured by a meter display
  • the notification device 24 is disposed in a place where the driver can visually recognize the vehicle while driving, for example, in an instrument panel in the vehicle.
  • the meter display can visually notify the driver of the road surface state by performing display in such a manner that the road surface state can be grasped.
  • the notification device 24 can be configured by a buzzer or a voice guidance device. In that case, the notification device 24 can audibly notify the driver of the road surface state by a buzzer sound or voice guidance.
  • the meter display device is exemplified as the notification device 24 that performs visual notification, the notification device 24 may be configured by a display device that displays information such as a head-up display.
  • each part which comprises the vehicle body side system 2 is connected through in-vehicle LAN (abbreviation of Local * AreaNetwork) by CAN (abbreviation for Controller
  • in-vehicle LAN abbreviation of Local * AreaNetwork
  • CAN abbreviation for Controller
  • the communication center 200 that exchanges information on road surface data with the vehicle danger avoidance device 100 performs a business of collecting road information and providing road information to vehicles and the like.
  • the communication center 200 and the vehicle communication device 23 may be configured to directly communicate with each other, but the communication center 200 can communicate with the vehicle communication device 23 through a communication system installed in various places such as roads. Yes.
  • the communication center 200 manages the road surface state information for each road location in the map data as a database, and maps the road surface state that changes every moment based on the received road surface data. Is going. That is, the communication center 200 updates the road surface state information for each road location in the map data based on the received road surface data.
  • the communication center 200 provides road surface data to the vehicle from the database.
  • the communication center 200 collects road surface data of the road on which the vehicle traveled from the vehicle travels, and updates the road surface data of each road in the map data based on the road surface data.
  • the communication center 200 also collects weather information and the like, corrects each road surface data based on the weather information and updates it as more reliable road surface data.
  • the communication center 200 acquires information on the amount of snow and the frozen road surface as weather information, and more accurate road surface data is sequentially stored by updating the snow covered road surface and the frozen road surface to the corresponding road surface data. I try to do it.
  • the communication center 200 provides the vehicle with the road surface data stored in the database so that more accurate road surface data is transmitted to the vehicle.
  • the communication center 200 collects road surface data from a large number of vehicles and updates the road surface data of each road in the map data stored in the database. As well as road surface data of a road to be traveled can be acquired.
  • the control unit 13 executes a road surface data transmission process shown in FIG. This process is executed, for example, every time the tire 3 makes one rotation based on the power supply from the power supply 15.
  • step S100 road surface condition detection processing is performed. Specifically, a high-frequency component is extracted from the detection signal of the acceleration sensor 11, that is, the output voltage, and the road surface ⁇ is detected based on the high-frequency component extracted during the contact section, or the type of the road surface is detected. Detect road surface condition. Then, ⁇ data indicating the road surface ⁇ or road surface data including the type of the road surface is created.
  • step S110 the road surface state obtained in step S100 is compared with the road surface state obtained during the previous tire rotation to determine whether or not the road surface state has changed. For example, when the type of the road surface changes so as to switch from a wet road to a dry road, or when the road surface ⁇ changes so that the road surface ⁇ switches from a state higher than a predetermined threshold to a low state, the road surface state changes. Judge that there was.
  • step S110 If a negative determination is made in step S110, the process proceeds to step S120, and periodic transmission processing is performed so that road surface data is transmitted at a transmission interval when there is no change in the road surface state. That is, as shown in FIG. 8A, road surface data is transmitted from the RF circuit 14 to the receiver 21 at a predetermined transmission interval set as regular transmission, for example, every time the tire 3 rotates a plurality of times. So that FIG. 8A shows a case where the vehicle continuously travels on a dry road as an example of no change.
  • step S110 the process proceeds to step S130, and a short cycle transmission process is performed so that road surface data is transmitted at the transmission interval at the time of change, which is shorter than the time of no change.
  • the road surface data is sent from the RF circuit 14 to the receiver 21 at a predetermined transmission interval set as short cycle transmission, for example, once or every time the tire 3 rotates once.
  • FIG. 8B shows, as an example at the time of change, a case where the vehicle travels on a road surface that switches from a dry road to a wet road and then switches to a dry road.
  • the road surface data is transmitted at a rate of once or a plurality of times each time the tire 3 rotates a plurality of times when the road surface state does not change, and when the road surface state changes, the transmission interval is made shorter than when there is no change. Data can be sent.
  • the vehicle danger avoidance device 100 sets the transmission interval of road surface data in accordance with changes in road surface conditions.
  • the transmission interval can be changed, and the transmission interval can be included in a timing for increasing the transmission interval. For this reason, it is possible to reduce the power required for data transmission at least at the timing of increasing the transmission interval, compared to the case where the transmission interval is always constant.
  • road surface data is transmitted at a rate of once every time the tire 3 rotates a plurality of times so that the power consumption of the power source 15 is reduced when the road surface state is unchanged.
  • the vehicle danger avoidance device 100 is configured to transmit road surface data when the road surface state changes, with a transmission interval shorter than when there is no change. In this way, it is possible to reduce the power required for data transmission by reducing the transmission of road surface data when there is no change in the road surface condition. Further, at the time of change, the transmission interval is made shorter than that at the time of no change, and for example, every time the tire 3 makes one rotation, the circuit surface data is transmitted once. For this reason, it becomes possible to quickly transmit the change in the road surface state to the vehicle body side system 2.
  • any one of the plurality of transmission data can be received by the receiver 21 such as a null. Even if not, the remaining transmission data can be received by the receiver 21. Therefore, transmission data can be more reliably transmitted to the vehicle body side system 2.
  • the transmission interval is shorter than when there is no change.
  • An example to do This is merely an example of setting the transmission interval of road surface data, and other forms may be used.
  • the transmission interval of road surface data may be made shorter when the road surface state is unchanged than when the road surface state is changed. Even in this case, since it is possible to include the timing to increase the transmission interval, the power required for data transmission is reduced at least at the timing to increase the transmission interval, as compared with the case where the transmission interval is always constant. Is possible.
  • both the change time and no change time are detected, but only the change time is detected, and the road surface data transmission interval is shortened compared to before detection at the time of change, etc. It may be changed.
  • the transmission interval of road surface data is set according to the change.
  • changes in the road surface condition may be detected due to noise or the like, if the changed road surface condition continues during the subsequent tire rotation after the change in the road surface condition is detected, the change in the road surface condition A corresponding transmission interval may be set. In this way, it is possible to prevent the driver from being notified until a change in the road surface state is detected in noise.
  • the timing at which the notification by the notification device 24 and the control corresponding to the road surface state in the vehicle motion control are performed may be made different. That is, the notification by the notification device 24 is not performed immediately after a change in the road surface state is detected, but is performed when the changed road surface state continues for a plurality of rotations of the tire 3. And about vehicle motion control, you may make it perform vehicle motion control according to the road surface state after changing immediately after detecting the change of a road surface state.
  • a ground contact area is identified from the detection signal of the acceleration sensor 11 which comprises a vibration detection part, and the road surface data by which the road surface state was shown by the calculation result of the level of the high frequency component in the detection signal in a ground contact area. It is used as. However, this is only an example of a method for detecting the road surface state using the detection signal at the vibration detection unit, and even if the road surface state is detected by another method using the detection signal at the vibration detection unit. good.
  • the vibration detection part can also be comprised by the element which can perform another vibration detection, for example, a piezoelectric element.
  • the power source 15 is not limited to a battery, and may be configured by a power generation element or the like. For example, if a vibration detection element is used, the power supply 15 can be configured while the vibration detection unit is configured by the vibration detection element.
  • the receiver 21 plays a role as a control unit that determines a change in road surface state based on road surface data.
  • a control unit may be provided separately from the receiver 21, or another ECU such as the brake ECU 22 may function as the control unit.
  • the road surface state estimation device is incorporated in the vehicle danger avoidance device.
  • the portion that estimates the road surface state for example, in the case of the above embodiment, the tire mount sensor 1 and the receiver 21 correspond to the road surface state estimation device. It is good also as a structure only.

Abstract

When a road surface condition is not changing, road surface data are transmitted by a tire mounted sensor (1) at a rate of once every time a tire (3) rotates a plurality of times, in order to reduce the power consumption from a power source. Further, when the road surface condition is changing, the road surface data are transmitted by the tire mounted sensor (1) with a transmission interval that is shorter than when the road surface condition is not changing. In this way, reducing the amount of road surface data that is transmitted when the road surface condition is not changing makes it possible to reduce the amount of power required for data transmission. Further, using a transmission interval that is shorter when the road surface condition is changing than when the road surface condition is not changing makes it possible for changes in the road surface condition to be conveyed rapidly to a vehicle body side system (2).

Description

タイヤマウントセンサおよびそれを含む路面状態推定装置Tire mount sensor and road surface state estimation device including the same 関連出願への相互参照Cross-reference to related applications
　本出願は、２０１６年７月１日に出願された日本特許出願番号２０１６－１３１７８９号と、２０１７年６月５日に出願された日本特許出願番号２０１７－１１０６８２号とに基づくもので、ここにその記載内容が参照により組み入れられる。 This application is based on Japanese Patent Application No. 2016-131789 filed on July 1, 2016 and Japanese Patent Application No. 2017-110682 filed on June 5, 2017. The description is incorporated by reference.
　本開示は、タイヤが受ける振動を検出し、振動データに基づいて路面状態を示す路面データを作成して車体側システムに伝えるタイヤマウントセンサおよびその振動データに基づいて路面状態を推定する路面状態推定装置に関するものである。 The present disclosure detects a vibration received by a tire, creates a road surface data indicating the road surface state based on the vibration data, and transmits the road surface state to the vehicle side system, and a road surface state estimation that estimates the road surface state based on the vibration data. It relates to the device.
　従来、特許文献１において、タイヤトレッドの裏面にタイヤマウントセンサを備え、タイヤマウントセンサにてタイヤに加えられる振動を検出すると共に、その振動の検出結果を車体側システムに伝え、路面状態の推定を行う路面状態推定装置が提案されている。この路面状態推定装置では、タイヤマウントセンサに備えられる振動検出部の検出信号に基づいて路面状態を推定している。具体的には、路面状態に応じて振動検出部の検出信号における高周波成分のレベルが変わる。このため、タイヤトレッドのうちタイヤマウントセンサの配置箇所と対応する部分が路面に接地しているときを接地区間中として、接地区間中の振動検出部の検出信号における高周波成分のレベルを、路面状態を示す路面データとして用いる。そして、タイヤが１回転する毎にタイヤマウントセンサから車体側システムに向けて路面データを送信し、車体側システムにおいて路面データに基づいて路面状態を推定している。より詳しくは、電圧値として示される検出信号の高周波成分を積分した積分電圧値を路面データとして用い、車体側システムにおいて、積分電圧値の大きさに基づいて路面摩擦係数（以下、路面μという）の推定などを行っている。 Conventionally, in Patent Document 1, a tire mount sensor is provided on the back surface of a tire tread, and vibration applied to the tire is detected by the tire mount sensor, and the detection result of the vibration is transmitted to the vehicle body system to estimate the road surface state. A road surface state estimating device to perform has been proposed. In this road surface state estimation device, the road surface state is estimated based on a detection signal of a vibration detection unit provided in the tire mount sensor. Specifically, the level of the high frequency component in the detection signal of the vibration detection unit changes according to the road surface state. For this reason, the level of the high-frequency component in the detection signal of the vibration detection unit in the grounding section is defined as the road surface state when the portion corresponding to the placement position of the tire mount sensor in the tire tread is in contact with the road surface. Used as road surface data. Each time the tire makes one revolution, road surface data is transmitted from the tire mount sensor to the vehicle body side system, and the road surface state is estimated based on the road surface data in the vehicle body side system. More specifically, an integrated voltage value obtained by integrating a high-frequency component of a detection signal indicated as a voltage value is used as road surface data. In the vehicle body side system, a road surface friction coefficient (hereinafter referred to as road surface μ) is based on the magnitude of the integrated voltage value. Etc. are estimated.
特開２０１５－１７４６３６号公報Japanese Patent Laying-Open No. 2015-174636
　しかしながら、タイヤが１回転する毎にタイヤマウントセンサから車体側システムに向けて路面データを送信すると、送信のために必要な電力が多くなり、タイヤマウントセンサの電源の大型化などを招くことになる。このため、タイヤマウントセンサからの路面データの送信に必要な電力を低減することが望まれる。 However, if road surface data is transmitted from the tire mount sensor to the vehicle body system every time the tire rotates, the power required for transmission increases, leading to an increase in the power supply of the tire mount sensor and the like. . For this reason, it is desired to reduce the power required for transmission of road surface data from the tire mount sensor.
　これを実現するには、タイヤが複数回転する毎に路面データの送信を行うようにすることで送信間隔を長くして送信回数を減らすことが考えられる。ところが、単に送信間隔を長くしたのでは、路面状態が変わったときにそれを迅速に車体側システムに伝えることができない。 To realize this, it is conceivable to increase the transmission interval and reduce the number of transmissions by transmitting road surface data every time the tire rotates a plurality of times. However, if the transmission interval is simply lengthened, it cannot be promptly transmitted to the vehicle body side system when the road surface condition changes.
　本開示は、データ送信に必要な電力を低減でき、かつ、路面状態の変化を迅速に車体側システムに伝えることができるタイヤマウントセンサおよびそれを含む路面状態推定装置を提供することを目的とする。 An object of the present disclosure is to provide a tire mount sensor that can reduce power required for data transmission and can quickly transmit a change in a road surface state to a vehicle body side system, and a road surface state estimation device including the tire mount sensor. .
　本開示の１つの観点におけるタイヤマウントセンサは、タイヤの裏面に取り付けられるタイヤマウントセンサであって、タイヤの振動の大きさに応じた検出信号を出力する振動検出部と、振動検出部の検出信号が示す振動データから路面状態を検出する信号処理部と、路面状態が表された路面データを送信する送信部と、を有し、信号処理部は、タイヤの回転に伴う路面状態の変化に応じて路面データの送信間隔を設定し、送信部より送信させる送信制御部を備えている。 The tire mount sensor in one viewpoint of this indication is a tire mount sensor attached to the back of a tire, Comprising: The vibration detection part which outputs the detection signal according to the size of the vibration of a tire, The detection signal of a vibration detection part A signal processing unit that detects a road surface state from vibration data indicated by and a transmission unit that transmits road surface data representing the road surface state, and the signal processing unit responds to changes in the road surface state due to tire rotation. A transmission control unit that sets a transmission interval of road surface data and transmits the road data from the transmission unit.
　このように、路面状態の変化に応じて路面データの送信間隔を設定することで、送信間隔を変化させることができ、送信間隔を長くするタイミングを含めることができる。このため、送信間隔を常に一定にする場合と比較して、少なくとも送信間隔を長くするタイミングにおいてデータ送信に必要な電力を低減することが可能となる。 Thus, by setting the transmission interval of road surface data according to the change in the road surface state, the transmission interval can be changed, and the timing for increasing the transmission interval can be included. For this reason, it is possible to reduce the power required for data transmission at least at the timing of increasing the transmission interval, compared to the case where the transmission interval is always constant.
　例えば、送信制御部は、タイヤの回転に伴って路面状態が変化した変化時と路面状態が変化していない無変化時とを検出し、無変化時にはタイヤが複数回転すると送信部より路面データを送信させると共に、変化時には無変化時よりも送信間隔を短くして送信部より路面データを送信させる。 For example, the transmission control unit detects when the road surface state has changed with the rotation of the tire and when the road surface state has not changed. At the time of change, the transmission interval is made shorter than when there is no change, and the road surface data is transmitted from the transmitter.
　このように、路面状態の無変化時に、路面データの送信を少なくすることで、データ送信に必要な電力を低減することが可能となる。また、変化時には、無変化時よりも送信間隔を短くすることで、路面状態の変化を迅速に車体側システムに伝えることが可能となる。 Thus, it becomes possible to reduce the power required for data transmission by reducing the transmission of road surface data when there is no change in the road surface condition. In addition, when the vehicle is changing, the transmission interval is made shorter than when there is no change, so that the change in the road surface condition can be quickly transmitted to the vehicle body system.
第１実施形態にかかる車両用危険回避装置の車両搭載状態でのブロック構成を示した図である。It is the figure which showed the block structure in the vehicle mounting state of the danger avoidance apparatus for vehicles concerning 1st Embodiment. タイヤマウントセンサのブロック図である。It is a block diagram of a tire mount sensor. タイヤマウントセンサが取り付けられたタイヤの断面模式図である。It is a cross-sectional schematic diagram of a tire to which a tire mount sensor is attached. タイヤ回転時における加速度センサの出力電圧波形図である。It is an output voltage waveform figure of an acceleration sensor at the time of tire rotation. アスファルト路のように路面μが比較的大きな高μ路面を走行している場合における加速度センサの出力電圧の変化を示した図である。It is the figure which showed the change of the output voltage of an acceleration sensor in the case of drive | working the high micro road surface where road surface (mu) is comparatively large like an asphalt road. 凍結路のように路面μが比較的小さな低μ路面を走行している場合における加速度センサの出力電圧の変化を示した図である。It is the figure which showed the change of the output voltage of an acceleration sensor in the case of drive | working on the low micro road surface where road surface (micro | micron | mu) is comparatively small like a frozen road. 高μ路面を走行している場合と低μ路面を走行している場合それぞれについて、接地区間中における出力電圧の周波数解析を行った結果を示した図である。It is the figure which showed the result of having performed the frequency analysis of the output voltage in the earthing | grounding area about the case where it is drive | working on the high micro road surface, and the case where it is driving on the low micro road surface, respectively. 路面データの送信間隔を決める間隔設定処理のフローチャートである。It is a flowchart of the interval setting process which determines the transmission interval of road surface data. 無変化時における路面データの送信の様子を示したタイムチャートである。It is the time chart which showed the mode of transmission of the road surface data at the time of no change. 変化時における路面データの送信の様子を示したタイムチャートである。It is a time chart which showed the mode of transmission of road surface data at the time of change.
　以下、本開示の実施形態について図に基づいて説明する。なお、以下の各実施形態相互において、互いに同一もしくは均等である部分には、同一符号を付して説明を行う。 Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.
　（第１実施形態）
　図１～図８Ａおよび図８Ｂを参照して、本実施形態にかかる路面状態推定装置を含む車両用危険回避装置１００について説明する。本実施形態にかかる車両用危険回避装置１００は、車両の各車輪に備えられるタイヤの接地面に加わる振動に基づいて走行中の路面状態を推定すると共に、路面状態に基づいて車両の危険性の報知や車両運動制御を行うものである。 (First embodiment)
With reference to FIGS. 1 to 8A and 8B, a vehicle danger avoidance device 100 including a road surface state estimation device according to the present embodiment will be described. The vehicle risk avoidance device 100 according to the present embodiment estimates a road surface state during traveling based on vibration applied to a ground contact surface of a tire provided on each wheel of the vehicle, and also determines the risk of the vehicle based on the road surface state. Notification and vehicle motion control are performed.
　図１および図２に示すように車両用危険回避装置１００は、車輪側に設けられたタイヤマウントセンサ１と、車体側に備えられた各部を含む車体側システム２とを有する構成とされている。車体側システム２としては、受信機２１、ブレーキ制御用の電子制御装置（以下、ブレーキＥＣＵという）２２、車両通信装置２３、報知装置２４などが備えられている。 As shown in FIGS. 1 and 2, the vehicle danger avoidance device 100 includes a tire mount sensor 1 provided on the wheel side and a vehicle body side system 2 including each part provided on the vehicle body side. . The vehicle body side system 2 includes a receiver 21, an electronic control device for brake control (hereinafter referred to as a brake ECU) 22, a vehicle communication device 23, a notification device 24, and the like.
　車両用危険回避装置１００は、タイヤマウントセンサ１よりタイヤ３と走行中の路面との間の路面μを示すデータなどの走行中の路面状態を表すデータを送信する。以下、路面μのデータのことをμデータといい、路面状態を表すデータのことを路面データという。 The vehicle danger avoidance device 100 transmits data representing the road surface condition during traveling, such as data indicating the road surface μ between the tire 3 and the road surface during traveling, from the tire mount sensor 1. Hereinafter, the data on the road surface μ is referred to as μ data, and the data representing the road surface state is referred to as road surface data.
　本実施形態の場合、車両用危険回避装置１００は、図１に示すように、受信機２１にてタイヤマウントセンサ１から送信された路面データを受信し、路面データに示される路面状態を報知装置２４より伝えている。これにより、例えば路面μが低いことや乾燥路やウェット路もしくは凍結路であることなど、路面状態をドライバに伝えることが可能となり、滑り易い路面である場合にはドライバに警告することも可能となる。また、車両用危険回避装置１００は、車両運動制御を行うブレーキＥＣＵ２２などに路面状態を伝えることで、危険を回避するための車両運動制御が行われるようにする。例えば、凍結時には、乾燥路の場合と比較してブレーキ操作量に対して発生させられる制動力が弱められるようにすることで、路面μが低いときに対応した車両運動制御となるようにする。また、車両用危険回避装置１００は、車両通信装置２３を通じて路面データを通信センター２００に送ることで、後述するように路面状態のマッピングが行えるようにしている。具体的には、タイヤマウントセンサ１および受信機２１は、以下のように構成されている。 In the case of this embodiment, as shown in FIG. 1, the vehicle danger avoidance device 100 receives road surface data transmitted from the tire mount sensor 1 by the receiver 21 and notifies the road surface state indicated by the road surface data. 24 tells. As a result, it is possible to inform the driver of the road surface condition such as low road surface μ, dry road, wet road or frozen road, and it is possible to warn the driver when the road surface is slippery. Become. Further, the vehicle risk avoidance device 100 transmits the vehicle surface state to the brake ECU 22 that performs vehicle motion control, so that vehicle motion control for avoiding danger is performed. For example, during freezing, the braking force generated with respect to the amount of brake operation is weakened compared to the case of a dry road, so that vehicle motion control corresponding to a low road surface μ is achieved. Further, the vehicle danger avoidance device 100 transmits road surface data to the communication center 200 through the vehicle communication device 23 so that the road surface state can be mapped as described later. Specifically, the tire mount sensor 1 and the receiver 21 are configured as follows.
　タイヤマウントセンサ１は、タイヤ側に備えられるタイヤ側装置である。タイヤマウントセンサ１は、図２に示すように、加速度センサ１１、温度センサ１２、制御部１３、ＲＦ回路１４および電源１５を備えた構成とされ、図３に示されるように、タイヤ３のトレッド３１の裏面側に設けられる。 The tire mount sensor 1 is a tire side device provided on the tire side. As shown in FIG. 2, the tire mount sensor 1 includes an acceleration sensor 11, a temperature sensor 12, a control unit 13, an RF circuit 14, and a power source 15. As shown in FIG. 31 is provided on the back side.
　加速度センサ１１は、タイヤに加わる振動を検出するための振動検出部を構成するものである。例えば、加速度センサ１１は、タイヤ３が回転する際にタイヤマウントセンサ１が描く円軌道に対して接する方向、つまり図３中の矢印Ｘで示すタイヤ接線方向の振動に応じた検出信号として、加速度の検出信号を出力する。より詳しくは、加速度センサ１１は、矢印Ｘで示す二方向のうちの一方向を正、反対方向を負とする出力電圧を検出信号として発生させる。 The acceleration sensor 11 constitutes a vibration detection unit for detecting vibration applied to the tire. For example, the acceleration sensor 11 detects the acceleration as a detection signal corresponding to the vibration in the tire tangential direction indicated by the arrow X in FIG. 3 in the direction in contact with the circular orbit drawn by the tire mount sensor 1 when the tire 3 rotates. The detection signal is output. More specifically, the acceleration sensor 11 generates, as a detection signal, an output voltage in which one of the two directions indicated by the arrow X is positive and the opposite is negative.
　温度センサ１２は、温度に応じた検出信号を出力するもので、タイヤ３のうちのタイヤマウントセンサ１の取り付け位置の温度を検出することで、走行路面の温度を測定している。 The temperature sensor 12 outputs a detection signal corresponding to the temperature, and measures the temperature of the traveling road surface by detecting the temperature at the mounting position of the tire mount sensor 1 in the tire 3.
　制御部１３は、信号処理部に相当する部分であり、加速度センサ１１の検出信号をタイヤ接線方向の振動データを表す検出信号として用いて、この検出信号を処理することで路面データを得て、それをＲＦ回路１４に伝える役割を果たす。具体的には、制御部１３は、加速度センサ１１の検出信号、つまり加速度センサ１１の出力電圧の時間変化に基づいて、タイヤ３の回転時における加速度センサ１１の接地区間を抽出している。なお、ここでいう接地区間とは、タイヤ３のトレッド３１のうち加速度センサ１１の配置箇所と対応する部分が路面接地している区間のことを意味している。本実施形態の場合、加速度センサ１１の配置箇所がタイヤマウントセンサ１の配置箇所とされているため、接地区間とはタイヤ３のトレッド３１のうちタイヤマウントセンサ１の配置箇所と対応する部分が路面接地している区間と同意である。 The control unit 13 is a portion corresponding to a signal processing unit, and uses the detection signal of the acceleration sensor 11 as a detection signal representing vibration data in the tire tangential direction, obtains road surface data by processing the detection signal, It plays a role of transmitting it to the RF circuit 14. Specifically, the control unit 13 extracts the ground contact section of the acceleration sensor 11 when the tire 3 rotates based on the detection signal of the acceleration sensor 11, that is, the time change of the output voltage of the acceleration sensor 11. Note that the contact section here means a section in which a portion of the tread 31 of the tire 3 corresponding to the position where the acceleration sensor 11 is disposed is grounded on the road surface. In the case of the present embodiment, since the location where the acceleration sensor 11 is disposed is the location where the tire mount sensor 1 is disposed, the portion corresponding to the location where the tire mount sensor 1 is disposed in the tread 31 of the tire 3 is the road surface. It is an agreement with the grounded section.
　そして、接地区間中における加速度センサ１１の検出信号に含まれる高周波成分が路面状態を表していることから、後述するように、制御部１３は、検出信号から高周波成分を抽出すると共に抽出した高周波成分に基づいて路面μなどの路面状態を検出している。 Since the high frequency component included in the detection signal of the acceleration sensor 11 in the contact section represents the road surface state, the control unit 13 extracts the high frequency component from the detection signal and extracts the high frequency component as described later. Is used to detect the road surface condition such as the road surface μ.
　また、本実施形態の場合は、温度センサ１２によって走行路面の温度を測定していることから、制御部１３は、走行路面の温度に基づいて、路面状態の検出を行ったり、加速度センサ１１の検出信号の高周波成分から求めた路面状態の補正などを行っている。 In this embodiment, since the temperature of the traveling road surface is measured by the temperature sensor 12, the control unit 13 detects the road surface state based on the temperature of the traveling road surface, The road surface condition obtained from the high-frequency component of the detection signal is corrected.
　このようにして、制御部１３は、路面状態の検出を行うと、その路面状態を示した路面データを生成し、それをＲＦ回路１４に伝える処理を行う。これにより、ＲＦ回路１４を通じて受信機２１に路面データが伝えられるようになっている。このとき、タイヤ３が１回転する毎にＲＦ回路１４から路面データを送信すると消費電力が大きくなる。このため、送信間隔を長くして送信回数を減らすようにしている。ただし、単に送信間隔を長くしたのでは、路面状態が変化したときに迅速に車体側システム２にその変化を伝えられない。このため、路面状態の変化に応じて送信間隔を設定するようにしている。 Thus, when the control unit 13 detects the road surface state, the control unit 13 generates road surface data indicating the road surface state, and performs a process of transmitting the road surface data to the RF circuit 14. Thereby, road surface data is transmitted to the receiver 21 through the RF circuit 14. At this time, if road surface data is transmitted from the RF circuit 14 every time the tire 3 makes one revolution, power consumption increases. For this reason, the transmission interval is lengthened to reduce the number of transmissions. However, if the transmission interval is simply increased, the change cannot be quickly transmitted to the vehicle body side system 2 when the road surface state changes. For this reason, the transmission interval is set according to the change in the road surface condition.
　具体的には、制御部１３は、ＣＰＵ、ＲＯＭ、ＲＡＭ、Ｉ／Ｏなどを備えた周知のマイクロコンピュータによって構成され、ＲＯＭなどに記憶されたプログラムに従って上記した処理を行っている。そして、制御部１３は、それらの処理を行う機能部として区間抽出部１３ａ、レベル算出部１３ｂ、データ生成部１３ｃおよび送信制御部１３ｄを備えている。 Specifically, the control unit 13 is configured by a known microcomputer including a CPU, ROM, RAM, I / O, and the like, and performs the above-described processing according to a program stored in the ROM. And the control part 13 is provided with the area extraction part 13a, the level calculation part 13b, the data generation part 13c, and the transmission control part 13d as a function part which performs those processes.
　区間抽出部１３ａは、加速度センサ１１の出力電圧で表される検出信号のピーク値を検出することで接地区間を抽出する。タイヤ回転時における加速度センサ１１の出力電圧波形は例えば図４に示す波形となる。この図に示されるように、タイヤ３の回転に伴ってトレッド３１のうち加速度センサ１１の配置箇所と対応する部分が接地し始めた接地開始時に、加速度センサ１１の出力電圧が極大値をとる。区間抽出部１３ａでは、この加速度センサ１１の出力電圧が極大値をとる接地開始時を第１ピーク値のタイミングとして検出している。さらに、図４に示されるように、タイヤ３の回転に伴ってトレッド３１のうち加速度センサ１１の配置箇所と対応する部分が接地していた状態から接地しなくなる接地終了時に、加速度センサ１１の出力電圧が極小値をとる。区間抽出部１３ａでは、この加速度センサ１１の出力電圧が極小値をとる接地終了時を第２ピーク値のタイミングとして検出している。 The section extracting unit 13a extracts the ground section by detecting the peak value of the detection signal represented by the output voltage of the acceleration sensor 11. The output voltage waveform of the acceleration sensor 11 during tire rotation is, for example, the waveform shown in FIG. As shown in this figure, the output voltage of the acceleration sensor 11 takes a maximum value at the start of grounding when the portion of the tread 31 corresponding to the location where the acceleration sensor 11 is disposed begins to ground as the tire 3 rotates. The section extraction unit 13a detects the start of grounding at which the output voltage of the acceleration sensor 11 takes a maximum value as the timing of the first peak value. Further, as shown in FIG. 4, the output of the acceleration sensor 11 at the end of the grounding in which the portion corresponding to the location where the acceleration sensor 11 is disposed in the tread 31 is grounded as the tire 3 rotates. The voltage takes a local minimum. The section extraction unit 13a detects the end of grounding when the output voltage of the acceleration sensor 11 takes a minimum value as the timing of the second peak value.
　加速度センサ１１の出力電圧が上記のようなタイミングでピーク値をとるのは、以下の理由による。すなわち、タイヤ３の回転に伴ってトレッド３１のうち加速度センサ１１の配置箇所と対応する部分が接地する際、加速度センサ１１の近傍においてタイヤ３のうちそれまで略円筒面であった部分が押圧されて平面状に変形する。このときの衝撃を受けることで、加速度センサ１１の出力電圧が第１ピーク値をとる。また、タイヤ３の回転に伴ってトレッド３１のうち加速度センサ１１の配置箇所と対応する部分が接地面から離れる際には、加速度センサ１１の近傍においてタイヤ３は押圧が解放されて平面状から略円筒状に戻る。このタイヤ３の形状が元に戻るときの衝撃を受けることで、加速度センサ１１の出力電圧が第２ピーク値をとる。このようにして、加速度センサ１１の出力電圧が接地開始時と接地終了時でそれぞれ第１、第２ピーク値をとるのである。また、タイヤ３が押圧される際の衝撃の方向と、押圧から開放される際の衝撃の方向は逆方向であるため、出力電圧の符号も逆方向となる。 The reason why the output voltage of the acceleration sensor 11 takes a peak value at the above timing is as follows. That is, when the portion of the tread 31 corresponding to the location where the acceleration sensor 11 is disposed contacts with the rotation of the tire 3, the portion of the tire 3 that has been a substantially cylindrical surface is pressed in the vicinity of the acceleration sensor 11. To be flat. By receiving an impact at this time, the output voltage of the acceleration sensor 11 takes the first peak value. Further, when the portion of the tread 31 corresponding to the location where the acceleration sensor 11 is disposed moves away from the grounding surface as the tire 3 rotates, the tire 3 is released from pressing in the vicinity of the acceleration sensor 11 and is substantially flat from the plane. Return to the cylindrical shape. By receiving an impact when the tire 3 returns to its original shape, the output voltage of the acceleration sensor 11 takes the second peak value. In this way, the output voltage of the acceleration sensor 11 takes the first and second peak values at the start of grounding and at the end of grounding, respectively. Moreover, since the direction of the impact when the tire 3 is pressed and the direction of the impact when released from the press are opposite directions, the sign of the output voltage is also opposite.
　そして、区間抽出部１３ａは、第１、第２ピーク値のタイミングを含めた検出信号のデータを抽出することで加速度センサ１１の接地区間を抽出し、接地区間中であることをレベル算出部１３ｂに伝える。 Then, the section extraction unit 13a extracts the ground contact section of the acceleration sensor 11 by extracting the detection signal data including the timings of the first and second peak values, and the level calculation unit 13b indicates that it is in the ground contact section. To tell.
　また、加速度センサ１１の出力電圧が第２ピーク値をとるタイミングが加速度センサ１１の接地終了時となるため、区間抽出部１３ａは、このタイミングで送信制御部１３ｄに検出信号を送っている。これにより、送信制御部１３ｄに対して、タイヤ３が１回転したことが伝えられる。 Also, since the timing at which the output voltage of the acceleration sensor 11 takes the second peak value is when the grounding of the acceleration sensor 11 ends, the section extraction unit 13a sends a detection signal to the transmission control unit 13d at this timing. As a result, the transmission control unit 13d is informed that the tire 3 has made one rotation.
　レベル算出部１３ｂは、区間抽出部１３ａから接地区間中であることが伝えられると、その期間中に加速度センサ１１の出力電圧に含まれるタイヤ３の振動に起因する高周波成分のレベルを算出する。そして、レベル算出部１３ｂは、その算出結果をμデータなどの路面データとしてデータ生成部１３ｃに伝える。ここで、路面μなどの路面状態を表わす指標として高周波成分のレベルを算出するようにしているが、その理由について図５Ａ、図５Ｂおよび図６を参照して説明する。 The level calculation unit 13b, when notified from the section extraction unit 13a that it is in the grounding section, calculates the level of the high-frequency component caused by the vibration of the tire 3 included in the output voltage of the acceleration sensor 11 during that period. Then, the level calculation unit 13b transmits the calculation result to the data generation unit 13c as road surface data such as μ data. Here, the level of the high-frequency component is calculated as an index representing the road surface state such as the road surface μ. The reason will be described with reference to FIGS. 5A, 5B, and 6. FIG.
　図５Ａは、アスファルト路のように路面μが比較的大きな高μ路面を走行している場合における加速度センサ１１の出力電圧の変化を示している。また、図５Ｂは、凍結路の相当する程度に路面μが比較的小さな低μ路面を走行している場合における加速度センサ１１の出力電圧の変化を示している。 FIG. 5A shows a change in the output voltage of the acceleration sensor 11 when traveling on a high μ road surface having a relatively large road surface μ such as an asphalt road. FIG. 5B shows the change in the output voltage of the acceleration sensor 11 when the vehicle is traveling on a low μ road surface where the road surface μ is relatively small to the extent corresponding to the frozen road.
　これらの図から分かるように、路面μにかかわらず、接地区間の最初と最後、つまり加速度センサ１１の接地開始時と接地終了時において第１、第２ピーク値が現れる。しかしながら、路面μの影響で、加速度センサ１１の出力電圧が変化する。例えば、低μ路面の走行時のように路面μが低いときには、タイヤ３のスリップによる細かな高周波振動が出力電圧に重畳される。このようなタイヤ３のスリップによる細かな高周波信号は、高μ路面の走行時のように路面μが高い場合にはあまり重畳されない。 As can be seen from these figures, the first and second peak values appear at the beginning and end of the contact section, that is, at the start and end of the contact of the acceleration sensor 11, regardless of the road surface μ. However, the output voltage of the acceleration sensor 11 changes due to the influence of the road surface μ. For example, when the road surface μ is low, such as when traveling on a low μ road surface, fine high-frequency vibration due to slip of the tire 3 is superimposed on the output voltage. Such a fine high-frequency signal due to the slip of the tire 3 is not superposed when the road surface μ is high, such as when traveling on a high μ road surface.
　このため、路面μが高い場合と低い場合それぞれについて、接地区間中における出力電圧の周波数解析を行うと、図６に示す結果となる。すなわち、低周波域では路面μが高い場合と低い場合のいずれを走行する場合にも高いレベルになるが、１ｋＨｚ以上の高周波域では路面μが低い場合の方が高い場合よりも高いレベルになる。このため、加速度センサ１１の出力電圧の高周波成分のレベルが路面状態を表す指標となる。 Therefore, when the frequency analysis of the output voltage during the grounding section is performed for each of the cases where the road surface μ is high and low, the result shown in FIG. 6 is obtained. In other words, in the low frequency range, the level is high when the road surface μ is high or low, but in the high frequency range of 1 kHz or higher, the level is higher when the road surface μ is low than when it is high. . For this reason, the level of the high frequency component of the output voltage of the acceleration sensor 11 serves as an index representing the road surface state.
　したがって、レベル算出部１３ｂによって接地区間中における加速度センサ１１の出力電圧の高周波成分のレベルを算出することで、これをμデータとすることが可能となる。また、μデータから、例えば路面μが低い場合に凍結路と判定するなど、路面μと対応する路面の種類を路面状態として検出することもできる。 Therefore, by calculating the level of the high frequency component of the output voltage of the acceleration sensor 11 during the grounding section by the level calculation unit 13b, this can be converted to μ data. Further, from the μ data, for example, when the road surface μ is low, the road surface type corresponding to the road surface μ can be detected as a road surface state, such as determining that the road is frozen.
　例えば、高周波成分のレベルは、加速度センサ１１の出力電圧から高周波成分を抽出し、接地区間中に抽出した高周波成分を積分することで算出することができる。具体的には、路面状態や路面μに応じて変化すると想定される周波数帯域ｆａ～ｆｂの高周波成分をフィルタリングなどによって抽出し、周波数解析によって取り出した周波数帯域ｆａ～ｆｂの高周波数成分の電圧を積分する。例えば、図示しないコンデンサにチャージさせる。このようにすれば、高μ路面を走行している場合のように路面μが高い場合よりも低μ路面を走行している場合のように路面μが低い場合の方がチャージ量が多くなる。このチャージ量をμデータとして用いて、μデータが示すチャージ量が多いほど路面μが低いというように路面μを推定できる。 For example, the level of the high frequency component can be calculated by extracting the high frequency component from the output voltage of the acceleration sensor 11 and integrating the extracted high frequency component during the grounding section. Specifically, the high frequency components of the frequency bands fa to fb that are assumed to change according to the road surface condition and the road surface μ are extracted by filtering or the like, and the voltages of the high frequency components of the frequency bands fa to fb extracted by the frequency analysis are obtained. Integrate. For example, a capacitor (not shown) is charged. In this way, the amount of charge increases when the road surface μ is low, such as when traveling on a low μ road surface, rather than when the road surface μ is high, such as when traveling on a high μ road surface. . Using this charge amount as the μ data, it is possible to estimate the road surface μ such that the larger the charge amount indicated by the μ data, the lower the road surface μ.
　データ生成部１３ｃは、基本的には、レベル算出部１３ｂでの算出結果に基づいて路面データを生成している。例えば、データ生成部１３ｃは、μデータをそのまま路面データとして採用したり、μデータから凍結路やアスファルト路のような路面状態を求めて、それを示すデータを路面データとして生成している。 The data generation unit 13c basically generates road surface data based on the calculation result of the level calculation unit 13b. For example, the data generation unit 13c adopts μ data as it is as road surface data, obtains a road surface state such as a frozen road or an asphalt road from μ data, and generates data indicating the road surface data as road surface data.
　また、上記したように、本実施形態の場合は、温度センサ１２によって走行路面の温度を測定している。これに基づき、データ生成部１３ｃは、温度センサ１２の検出信号を入力することで路面温度を取得し、取得した路面温度から路面の種類を検出したり、μデータの補正もしくはμデータから得た路面の種類の補正を行っている。 Further, as described above, in the present embodiment, the temperature of the traveling road surface is measured by the temperature sensor 12. Based on this, the data generation unit 13c acquires the road surface temperature by inputting the detection signal of the temperature sensor 12, detects the type of the road surface from the acquired road surface temperature, or obtains from μ data correction or μ data. The type of road is corrected.
　例えば、温度センサ１２で検出された路面温度が０℃よりも低いマイナスであった場合には、データ生成部１３ｃは、路面の種類として路面が凍結状態であることを検出している。さらに、データ生成部１３ｃは、加速度センサ１１の検出信号の高周波成分から求めたμデータもしくはμデータが示す路面の種類が温度センサ１２で検出された路面温度と合致しない場合には、それを補正したり、路面状態の検出結果として採用しないようにする。例えば、加速度センサ１１の検出信号の高周波成分から求めた路面の種類が凍結状態であった場合において、温度センサ１２で検出された路面温度が４０℃であったときには、凍結状態という路面の種類の検出結果に誤りがあると考えられる。この場合には、データ生成部１３ｃは、レベル算出部１３ｂから伝えられる結果を路面の種類の検出結果としては採用しないようにする。同様に、μデータが示す路面μが路面温度から得た路面の種類と合致しない場合、例えば路面温度から凍結状態と検出されているのにμデータが示す路面μが高い場合には、μデータが示す路面μを補正して補正前よりも低い値にしたりする。 For example, when the road surface temperature detected by the temperature sensor 12 is a negative value lower than 0 ° C., the data generation unit 13c detects that the road surface is frozen as the type of the road surface. Furthermore, the data generation unit 13c corrects the μ data obtained from the high frequency component of the detection signal of the acceleration sensor 11 or the road surface type indicated by the μ data when the road surface temperature detected by the temperature sensor 12 does not match. Or not adopted as a road surface condition detection result. For example, when the road surface type obtained from the high-frequency component of the detection signal of the acceleration sensor 11 is in a frozen state, and the road surface temperature detected by the temperature sensor 12 is 40 ° C., the road surface type of the frozen state is set. It is thought that there is an error in the detection result. In this case, the data generation unit 13c does not adopt the result transmitted from the level calculation unit 13b as the detection result of the road surface type. Similarly, if the road surface μ indicated by the μ data does not match the type of road surface obtained from the road surface temperature, for example, if the road surface μ indicated by the μ data is high even though the road surface temperature is detected as frozen, the μ data Is corrected to a lower value than before the correction.
　送信制御部１３ｄは、データ生成部１３ｃが生成した路面データに基づいて、路面状態の変化を検出している。そして、送信制御部１３ｄは、検出した路面状態の変化に応じて、ＲＦ回路１４による路面データの送信間隔、換言すれば送信周期を設定し、その間隔に応じてＲＦ回路１４に対して送信トリガを出力する。例えば、乾燥路からウェット路に変化した場合、逆にウェット路から乾燥路に変化した場合、高μ路から低μ路に変化したり、低μ路から高μ路に変化した場合などが、路面状態の変化として検出される。そして、その路面状態の変化に応じて、例えば変化したときに、送信制御部１３ｄから送信トリガが出力される。なお、本実施形態では、後述するように、送信トリガについては、路面状態の変化に応じて、例えばタイヤ３の１回転毎もしくは複数回転毎に出力されるようにしている。送信トリガをタイヤ３の回転のどのタイミングで出力するかについては任意であるが、例えば接地終了時、つまり加速度センサ１１の出力電圧が極小値の第２ピーク値となるタイミングなどに送信トリガが出力されるようにしている。 The transmission control unit 13d detects a change in road surface state based on the road surface data generated by the data generation unit 13c. Then, the transmission control unit 13d sets the transmission interval of road surface data by the RF circuit 14 according to the detected change in the road surface state, in other words, the transmission cycle, and the transmission trigger for the RF circuit 14 according to the interval. Is output. For example, when changing from dry road to wet road, conversely changing from wet road to dry road, changing from high μ road to low μ road, changing from low μ road to high μ road, etc. It is detected as a change in road surface condition. Then, a transmission trigger is output from the transmission control unit 13d when, for example, the road surface state changes according to the change in the road surface state. In the present embodiment, as will be described later, the transmission trigger is output, for example, every one rotation or a plurality of rotations of the tire 3 according to a change in the road surface state. The timing at which the transmission trigger is output at any timing of the rotation of the tire 3 is arbitrary. For example, the transmission trigger is output at the end of the grounding, that is, at the timing when the output voltage of the acceleration sensor 11 reaches the second minimum peak value. To be.
　具体的には、送信制御部１３ｄは、データ生成部１３ｃが生成したデータが示す路面状態が変化していない無変化時には、定期送信として所定の送信間隔で路面データの送信が行われるように送信トリガを発生させる。この無変化時には、消費電力低減による電池寿命の向上を図るためや、他車輪とのデータ送信の重複によって受信機２１が受信できなくなることを防止するために、タイヤ３が複数回転する毎に路面データが１回送信される送信間隔としている。例えば、タイヤ３が５回転する毎に１回の割合で路面データを送信する。この場合、およそ１０ｍ走行する毎に路面データが車体側システム２に伝えられることになる。 Specifically, the transmission control unit 13d performs transmission so that road surface data is transmitted at a predetermined transmission interval as regular transmission when the road surface state indicated by the data generated by the data generation unit 13c does not change. Generate a trigger. At the time of no change, the road surface every time the tire 3 rotates a plurality of times in order to improve the battery life by reducing the power consumption or to prevent the receiver 21 from receiving data due to duplication of data transmission with other wheels. The transmission interval at which data is transmitted once is used. For example, road surface data is transmitted at a rate of once every time the tire 3 rotates five times. In this case, the road surface data is transmitted to the vehicle body side system 2 every time the vehicle travels approximately 10 m.
　また、送信制御部１３ｄは、データ生成部１３ｃが生成したデータが示す路面状態が変化した変化時には、短周期送信として無変化時よりも短い所定の送信間隔で路面データの送信が行われるように送信トリガを発生させる。例えば、変化時には、タイヤ３が１回転する毎に路面データが送信される送信間隔としている。このとき、タイヤ３が１回転する毎に１回だけ路面データが送信される送信間隔としても良いし、さらに、タイヤ３が１回転する毎に同じ路面データを複数回送信されるようにすることもできる。このように、タイヤ３が１回転する毎に路面データを複数回送信すれば、ヌルなどで複数回の送信データのうちのいずれかが受信機２１で受信できなかったとしても、残りの送信データが受信機２１で受信されるようにできる。したがって、より確実に車体側システム２に送信データを伝えることが可能となる。 Further, the transmission control unit 13d transmits the road surface data at a predetermined transmission interval that is shorter than that when there is no change as short cycle transmission when the road surface state indicated by the data generated by the data generation unit 13c changes. Generate a transmission trigger. For example, at the time of change, the transmission interval is set so that road surface data is transmitted every time the tire 3 makes one rotation. At this time, it is good also as a transmission interval by which road surface data is transmitted only once for every rotation of the tire 3, and furthermore, the same road surface data is transmitted a plurality of times for each rotation of the tire 3. You can also. In this way, if the road surface data is transmitted a plurality of times each time the tire 3 makes one rotation, even if any of the plurality of transmission data cannot be received by the receiver 21 due to a null or the like, the remaining transmission data Can be received by the receiver 21. Therefore, transmission data can be more reliably transmitted to the vehicle body side system 2.
　なお、本実施形態の場合、区間抽出部１３ａから加速度センサ１１が接地終了するタイミング毎に検出信号が送信制御部１３ｄに送られてくることから、送信制御部１３ｄはその検出信号に基づいてタイヤ３の回転数を検出することができる。勿論、それ以外の手法、例えば区間抽出部１３ａから加速度センサ１１の出力電圧が第１ピーク値を取る毎に検出信号が送られるようにしたり、接地区間の抽出が行われる毎に検出信号が送られるようにしても、同様にタイヤ３の回転数を検出できる。 In the case of the present embodiment, since the detection signal is sent from the section extraction unit 13a to the transmission control unit 13d at every timing when the acceleration sensor 11 finishes grounding, the transmission control unit 13d determines that the tire is based on the detection signal. The number of rotations of 3 can be detected. Of course, other methods, for example, a detection signal is sent every time the output voltage of the acceleration sensor 11 takes the first peak value from the section extraction unit 13a, or a detection signal is sent every time a ground section is extracted. Even if it makes it, it can detect the rotation speed of the tire 3 similarly.
　ＲＦ回路１４は、データ生成部１３ｃから伝えられたμデータなどの路面データを受信機２１に対して送信する送信部を構成するものであり、本実施形態の場合、送信制御部１３ｄからの送信トリガに基づいて路面データの送信を行っている。ＲＦ回路１４と受信機２１との間の通信は、例えば、Ｂｌｕｅｔｏｏｔｈ（登録商標）などの公知の近距離無線通信技術によって実施可能である。路面データを送信するタイミングについては任意であるが、上記したように、本実施形態では、路面状態の無変化時にはタイヤ３が複数回転する毎に１回の割合で路面データが送信されるようにしている。そして、路面状態の変化時には、無変化時よりも送信間隔を短くしてタイヤ３が１回転する毎に路面データが送信されるようにしている。このように、路面状態の無変化時には、路面データの送信が少なくなるようにすることで消費電力を低減することが可能となり、変化時には、路面データの送信を無変化時より多くすることで迅速に車体側システム２に路面状態の変化を伝えることが可能となる。 The RF circuit 14 constitutes a transmission unit that transmits road surface data such as μ data transmitted from the data generation unit 13c to the receiver 21, and in the case of the present embodiment, transmission from the transmission control unit 13d. Road surface data is transmitted based on the trigger. Communication between the RF circuit 14 and the receiver 21 can be performed by a known short-range wireless communication technique such as Bluetooth (registered trademark). The timing for transmitting the road surface data is arbitrary, but as described above, in this embodiment, when the road surface condition is unchanged, the road surface data is transmitted at a rate of once every time the tire 3 rotates a plurality of times. ing. When the road surface condition changes, the transmission interval is shorter than when there is no change, and the road surface data is transmitted every time the tire 3 makes one revolution. In this way, it is possible to reduce power consumption by reducing the transmission of road surface data when there is no change in the road surface condition, and quickly by increasing the transmission of road surface data when there is no change. It is possible to transmit the change of the road surface state to the vehicle body side system 2.
　また、路面データについては、車両に備えられたタイヤ３毎に予め備えられている車輪の固有識別情報（以下、ＩＤ情報という）と共に送られる。各車輪の位置については、車輪が車両のどの位置に取り付けられているかを検出する周知の車輪位置検出装置によって特定できることから、受信機２１にＩＤ情報と共に路面データを伝えることで、どの車輪のデータであるかが判別可能になる。 Further, the road surface data is sent together with the unique identification information (hereinafter referred to as ID information) of the wheels provided in advance for each tire 3 provided in the vehicle. The position of each wheel can be specified by a well-known wheel position detection device that detects which position of the vehicle the wheel is attached to. Therefore, by transmitting road surface data together with ID information to the receiver 21, data on which wheel is detected. Can be determined.
　電源１５は、例えば電池などによって構成され、タイヤマウントセンサ１の各部を駆動するための電源供給を行っている。 The power source 15 is constituted by a battery, for example, and supplies power for driving each part of the tire mount sensor 1.
　一方、受信機２１は、タイヤマウントセンサ１より送信された路面データを受信し、これに基づいて路面状態を推定すると共に推定した路面状態を報知装置２４に伝え、必要に応じて報知装置２４より路面状態をドライバに伝える。これにより、ドライバは路面状態に対応した運転を心掛けるようになり、車両の危険性を回避することが可能となる。例えば、報知装置２４を通じて推定された路面状態を常に表示するようにしても良いし、推定された路面状態がウェット路や凍結路や低μ路等のように運転をより慎重に行う必要があるときにのみ路面状態を表示してドライバに警告するようにしても良い。また、受信機２１からブレーキＥＣＵ２２などの車両運動制御を実行するためのＥＣＵに対して路面状態を伝えており、伝えられた路面状態に基づいて車両運動制御が実行されるようにしている。さらに、受信機２１は、路面データを車両通信装置２３に出力する処理を行っている。これに基づき、車両通信装置２３から道路情報などを収集している通信センター２００に路面データが送られるようになっている。 On the other hand, the receiver 21 receives the road surface data transmitted from the tire mount sensor 1, estimates the road surface state based on the road surface data, and transmits the estimated road surface state to the notification device 24, and from the notification device 24 as necessary. Inform the driver of the road surface condition. As a result, the driver tries to drive corresponding to the road surface condition, and the danger of the vehicle can be avoided. For example, the estimated road surface state may be always displayed through the notification device 24, or the estimated road surface state needs to be operated more carefully such as a wet road, a frozen road, a low μ road, or the like. Only when the road surface condition is displayed, the driver may be warned. Further, the road surface state is transmitted from the receiver 21 to the ECU for executing the vehicle motion control such as the brake ECU 22, and the vehicle motion control is executed based on the transmitted road surface state. Furthermore, the receiver 21 performs a process of outputting road surface data to the vehicle communication device 23. Based on this, road surface data is sent from the vehicle communication device 23 to the communication center 200 collecting road information and the like.
　ブレーキＥＣＵ２２は、様々なブレーキ制御を行う制動制御装置を構成するものである。具体的には、ブレーキＥＣＵ２２は、ブレーキ液圧制御用のアクチュエータを駆動することでホイールシリンダ圧を増減して制動力を制御する。また、ブレーキＥＣＵ２２は、各車輪の制動力を独立して制御することもできる。このブレーキＥＣＵ２２により、受信機２１から路面状態が伝えられると、それに基づいて車両運動制御として制動力の制御を行っている。例えば、ブレーキＥＣＵ２２は、伝えられた路面状態が凍結路であることを示していた場合、路面μが大きい場合と比較して、ドライバによるブレーキ操作量に対して発生させる制動力を弱めるようにする。これにより、車輪スリップを抑制でき、車両の危険性を回避することが可能となる。 Brake ECU22 comprises the brake control apparatus which performs various brake control. Specifically, the brake ECU 22 controls the braking force by driving the brake fluid pressure control actuator to increase or decrease the wheel cylinder pressure. The brake ECU 22 can also control the braking force of each wheel independently. When the road surface state is transmitted from the receiver 21 by the brake ECU 22, the braking force is controlled as vehicle motion control based on the road surface state. For example, when the transmitted road surface state indicates that the road surface is a frozen road, the brake ECU 22 weakens the braking force generated with respect to the amount of brake operation performed by the driver as compared with the case where the road surface μ is large. . Thereby, wheel slip can be suppressed and it becomes possible to avoid the danger of a vehicle.
　車両通信装置２３は、路車間通信を行うことができるものであり、例えば道路などに設置されている図示しない通信システムを介して、通信センター２００との情報交換を行う。本実施形態の場合、車両通信装置２３は、受信機２１から伝えられた路面データを通信センター２００に送信している。逆に、車両通信装置２３は、通信センター２００からより正確な路面データを受信することもできる。 The vehicle communication device 23 can perform road-to-vehicle communication, and exchanges information with the communication center 200 via a communication system (not shown) installed on a road, for example. In the case of the present embodiment, the vehicle communication device 23 transmits road surface data transmitted from the receiver 21 to the communication center 200. Conversely, the vehicle communication device 23 can also receive more accurate road surface data from the communication center 200.
　報知装置２４は、例えばメータ表示器などで構成され、ドライバに対して路面状態を報知する際に用いられる。報知装置２４をメータ表示器で構成する場合、ドライバが車両の運転中に視認可能な場所に配置され、例えば車両におけるインストルメントパネル内に設置される。メータ表示器は、受信機２１から路面状態が伝えられると、その路面状態が把握できる態様で表示を行うことで、視覚的にドライバに対して路面状態を報知することができる。 The notification device 24 is composed of, for example, a meter display and is used when notifying the driver of the road surface state. When the notification device 24 is configured by a meter display, the notification device 24 is disposed in a place where the driver can visually recognize the vehicle while driving, for example, in an instrument panel in the vehicle. When the road surface state is transmitted from the receiver 21, the meter display can visually notify the driver of the road surface state by performing display in such a manner that the road surface state can be grasped.
　なお、報知装置２４をブザーや音声案内装置などで構成することもできる。その場合、報知装置２４は、ブザー音や音声案内によって、聴覚的にドライバに対して路面状態を報知することができる。また、視覚的な報知を行う報知装置２４としてメータ表示器を例に挙げたが、ヘッドアップディスプレイなどの情報表示を行う表示器によって報知装置２４を構成しても良い。 Note that the notification device 24 can be configured by a buzzer or a voice guidance device. In that case, the notification device 24 can audibly notify the driver of the road surface state by a buzzer sound or voice guidance. In addition, although the meter display device is exemplified as the notification device 24 that performs visual notification, the notification device 24 may be configured by a display device that displays information such as a head-up display.
　以上のようにして、本実施形態にかかる車両用危険回避装置１００が構成されている。なお、車体側システム２を構成する各部が例えばＣＡＮ（Controller AreaNetworkの略）通信などによる車内ＬＡＮ（Local AreaNetworkの略）を通じて接続されている。このため、車内ＬＡＮを通じて各部が互いに情報伝達できるようになっている。 As described above, the vehicle danger avoidance device 100 according to the present embodiment is configured. In addition, each part which comprises the vehicle body side system 2 is connected through in-vehicle LAN (abbreviation of Local * AreaNetwork) by CAN (abbreviation for Controller | AreaNetwork) etc., for example. For this reason, each part can communicate with each other through the in-vehicle LAN.
　一方、車両用危険回避装置１００と路面データに関する情報交換を行う通信センター２００は、道路情報の収集を行うと共に道路情報を車両などに提供する事業を行っている。通信センター２００と車両通信装置２３とが直接通信を行える形態とされていても良いが、通信センター２００は道路などの各所に設置された通信システムを通じて車両通信装置２３との通信が可能となっている。 On the other hand, the communication center 200 that exchanges information on road surface data with the vehicle danger avoidance device 100 performs a business of collecting road information and providing road information to vehicles and the like. The communication center 200 and the vehicle communication device 23 may be configured to directly communicate with each other, but the communication center 200 can communicate with the vehicle communication device 23 through a communication system installed in various places such as roads. Yes.
　本実施形態の場合、通信センター２００は、地図データ中の各道路の場所ごとの路面状態の情報をデータベースとして管理しており、受信した路面データに基づいて時々刻々と変化する路面状態のマッピングを行っている。つまり、通信センター２００は、受信した路面データに基づいて地図データ中の各道路の場所ごとの路面状態の情報を更新している。そして、通信センター２００は、そのデータベースから車両に対して路面データを提供している。 In the case of this embodiment, the communication center 200 manages the road surface state information for each road location in the map data as a database, and maps the road surface state that changes every moment based on the received road surface data. Is going. That is, the communication center 200 updates the road surface state information for each road location in the map data based on the received road surface data. The communication center 200 provides road surface data to the vehicle from the database.
　具体的には、通信センター２００は、車両から送られてくる車両が走行した道路の路面データを収集し、その路面データに基づいて地図データ中の各道路の路面データを更新している。また、通信センター２００は、天気情報等も収集しており、天気情報等に基づいて各路面データを補正し、より確かな路面データとして更新している。例えば、通信センター２００は、天気情報として積雪量や凍結路面に関する情報を取得しており、積雪路面や凍結路面については、それに対応する路面データに更新することでより正確な路面データが逐次記憶されるようにしている。そして、通信センター２００は、データベースに記憶してある路面データを車両に提供することで、より正確な路面データを車両に伝えるようにしている。このとき、通信センター２００では、多数の車両から路面データを収集してデータベースに記憶している地図データ中の各道路の路面データを更新していることから、各車両は、現在位置の路面データだけでなく、走行予定の道路の路面データについても取得できる。 Specifically, the communication center 200 collects road surface data of the road on which the vehicle traveled from the vehicle travels, and updates the road surface data of each road in the map data based on the road surface data. The communication center 200 also collects weather information and the like, corrects each road surface data based on the weather information and updates it as more reliable road surface data. For example, the communication center 200 acquires information on the amount of snow and the frozen road surface as weather information, and more accurate road surface data is sequentially stored by updating the snow covered road surface and the frozen road surface to the corresponding road surface data. I try to do it. The communication center 200 provides the vehicle with the road surface data stored in the database so that more accurate road surface data is transmitted to the vehicle. At this time, the communication center 200 collects road surface data from a large number of vehicles and updates the road surface data of each road in the map data stored in the database. As well as road surface data of a road to be traveled can be acquired.
　続いて、本実施形態にかかる車両用危険回避装置１００におけるタイヤマウントセンサ１の作動について、図７、図８Ａおよび図８Ｂを参照して説明する。 Subsequently, the operation of the tire mount sensor 1 in the vehicle danger avoidance device 100 according to the present embodiment will be described with reference to FIGS. 7, 8A and 8B.
　各車輪のタイヤマウントセンサ１では、制御部１３にて、図７に示す路面データ送信処理を実行している。この処理は、電源１５からの電力供給に基づいて、例えばタイヤ３が１回転する毎に実行される。 In the tire mount sensor 1 of each wheel, the control unit 13 executes a road surface data transmission process shown in FIG. This process is executed, for example, every time the tire 3 makes one rotation based on the power supply from the power supply 15.
　まず、ステップＳ１００では、路面状態検出の処理を行う。具体的には、加速度センサ１１の検出信号、つまり出力電圧から高周波成分を抽出し、接地区間中に抽出した高周波成分に基づいて路面μの検出を行ったり、路面の種類の検出を行うことで、路面状態を検出する。そして、路面μを示すμデータもしくは路面の種類を含む路面データを作成する。 First, in step S100, road surface condition detection processing is performed. Specifically, a high-frequency component is extracted from the detection signal of the acceleration sensor 11, that is, the output voltage, and the road surface μ is detected based on the high-frequency component extracted during the contact section, or the type of the road surface is detected. Detect road surface condition. Then, μ data indicating the road surface μ or road surface data including the type of the road surface is created.
　次に、ステップＳ１１０では、ステップＳ１００で得た路面状態と前回のタイヤ回転時に得た路面状態とを比較し、路面状態に変化があったか否かを判定する。例えば、ウェット路から乾燥路に切り替わるように路面の種類が変わった場合や、路面μが所定の閾値よりも高い状態から低い状態に切り替わるように路面μが変わった場合に、路面状態に変化があったと判定している。 Next, in step S110, the road surface state obtained in step S100 is compared with the road surface state obtained during the previous tire rotation to determine whether or not the road surface state has changed. For example, when the type of the road surface changes so as to switch from a wet road to a dry road, or when the road surface μ changes so that the road surface μ switches from a state higher than a predetermined threshold to a low state, the road surface state changes. Judge that there was.
　そして、ステップＳ１１０で否定判定された場合には、ステップＳ１２０に進み、路面状態の無変化時の送信間隔で路面データの送信が行われるようにする定期送信処理を行う。すなわち、図８Ａに示すように、定期送信として設定される所定の送信間隔毎、例えばタイヤ３が複数回転する毎に１回の割合で路面データがＲＦ回路１４から受信機２１に向けて送信されるようにする。なお、図８Ａは、無変化時の一例として、車両が乾燥路を継続して走行した場合を示している。 If a negative determination is made in step S110, the process proceeds to step S120, and periodic transmission processing is performed so that road surface data is transmitted at a transmission interval when there is no change in the road surface state. That is, as shown in FIG. 8A, road surface data is transmitted from the RF circuit 14 to the receiver 21 at a predetermined transmission interval set as regular transmission, for example, every time the tire 3 rotates a plurality of times. So that FIG. 8A shows a case where the vehicle continuously travels on a dry road as an example of no change.
　一方、ステップＳ１１０で肯定判定された場合には、ステップＳ１３０に進み、無変化時よりも送信間隔が短くされた変化時の送信間隔で路面データの送信が行われるようにする短周期送信処理を行う。すなわち、図８Ｂに示すように、短周期送信として設定される所定の送信間隔毎、例えばタイヤ３が１回転する毎に１回もしくは複数回の割合で路面データがＲＦ回路１４から受信機２１に向けて送信されるようにする。なお、図８Ｂは、変化時の一例として、車両が乾燥路からウェット路に切り替わり、さらに乾燥路に切り替わる路面を走行した場合を示している。 On the other hand, if an affirmative determination is made in step S110, the process proceeds to step S130, and a short cycle transmission process is performed so that road surface data is transmitted at the transmission interval at the time of change, which is shorter than the time of no change. Do. That is, as shown in FIG. 8B, the road surface data is sent from the RF circuit 14 to the receiver 21 at a predetermined transmission interval set as short cycle transmission, for example, once or every time the tire 3 rotates once. To be sent to. FIG. 8B shows, as an example at the time of change, a case where the vehicle travels on a road surface that switches from a dry road to a wet road and then switches to a dry road.
　このようにして、路面状態の無変化時にはタイヤ３が複数回転する毎に１回もしくは複数回の割合で路面データが送信され、路面状態の変化時には無変化時よりも送信間隔を短くして路面データが送信されるようにできる。 In this way, the road surface data is transmitted at a rate of once or a plurality of times each time the tire 3 rotates a plurality of times when the road surface state does not change, and when the road surface state changes, the transmission interval is made shorter than when there is no change. Data can be sent.
　以上説明したように、本実施形態にかかる車両用危険回避装置１００は、路面状態の変化に応じて路面データの送信間隔を設定している。このように、路面状態の変化に応じて路面データの送信間隔を設定することで、送信間隔を変化させることができ、送信間隔を送信間隔を長くするタイミングを含めることができる。このため、送信間隔を常に一定にする場合と比較して、少なくとも送信間隔を長くするタイミングにおいてデータ送信に必要な電力を低減することが可能となる。 As described above, the vehicle danger avoidance device 100 according to this embodiment sets the transmission interval of road surface data in accordance with changes in road surface conditions. Thus, by setting the road surface data transmission interval according to the change in the road surface state, the transmission interval can be changed, and the transmission interval can be included in a timing for increasing the transmission interval. For this reason, it is possible to reduce the power required for data transmission at least at the timing of increasing the transmission interval, compared to the case where the transmission interval is always constant.
　具体的には、本実施形態の車両用危険回避装置１００では、路面状態の無変化時には電源１５の消費電力が少なくなるようにタイヤ３が複数回転する毎に１回の割合で路面データが送信されるようにしている。また、車両用危険回避装置１００は、路面状態の変化時には、無変化時よりも送信間隔を短くして路面データが送信されるようにしている。このように、路面状態の無変化時に、路面データの送信が少なくなるようにすることで、データ送信に必要な電力を低減することが可能となる。また、変化時には、無変化時よりも送信間隔を短くし、例えばタイヤ３が１回転する毎に１回もしくは複数回路面データを送信するようにしている。このため、路面状態の変化を迅速に車体側システム２に伝えることが可能となる。 Specifically, in the vehicle danger avoidance device 100 of this embodiment, road surface data is transmitted at a rate of once every time the tire 3 rotates a plurality of times so that the power consumption of the power source 15 is reduced when the road surface state is unchanged. To be. Further, the vehicle danger avoidance device 100 is configured to transmit road surface data when the road surface state changes, with a transmission interval shorter than when there is no change. In this way, it is possible to reduce the power required for data transmission by reducing the transmission of road surface data when there is no change in the road surface condition. Further, at the time of change, the transmission interval is made shorter than that at the time of no change, and for example, every time the tire 3 makes one rotation, the circuit surface data is transmitted once. For this reason, it becomes possible to quickly transmit the change in the road surface state to the vehicle body side system 2.
　さらに、路面状態の変化時に、タイヤ３が１回転する毎に同じ路面データを複数回送信されるようにすれば、ヌルなどで複数回の送信データのうちのいずれかが受信機２１で受信できなかったとしても、残りの送信データが受信機２１で受信されるようにできる。したがって、より確実に車体側システム２に送信データを伝えることが可能となる。 Furthermore, if the same road surface data is transmitted a plurality of times each time the tire 3 rotates once when the road surface state changes, any one of the plurality of transmission data can be received by the receiver 21 such as a null. Even if not, the remaining transmission data can be received by the receiver 21. Therefore, transmission data can be more reliably transmitted to the vehicle body side system 2.
　（他の実施形態）
　本開示は、上記した実施形態に準拠して記述されたが、当該実施形態に限定されるものではなく、様々な変形例や均等範囲内の変形をも包含する。加えて、様々な組み合わせや形態、さらには、それらに一要素のみ、それ以上、あるいはそれ以下、を含む他の組み合わせや形態をも、本開示の範疇や思想範囲に入るものである。 (Other embodiments)
Although the present disclosure has been described based on the above-described embodiment, the present disclosure is not limited to the embodiment, and includes various modifications and modifications within an equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.
　例えば、上記実施形態では、路面状態の変化に応じて路面データの送信間隔を設定する一例として、路面状態の変化時と無変化時とを検出し、変化時に無変化時よりも送信間隔を短くする例を示した。これは路面データの送信間隔の設定例の一例を示したに過ぎず、他の形態としても良い。例えば、路面状態の無変化時に変化時よりも路面データの送信間隔が短くなるようにしても良い。このようにしても、送信間隔を長くするタイミングを含めることができることから、送信間隔を常に一定にする場合と比較して、少なくとも送信間隔を長くするタイミングにおいてデータ送信に必要な電力を低減することが可能となる。さらに、路面状態の変化について、変化時と無変化時の双方を検出するようにしているが、変化時のみを検出し、変化時に路面データの送信間隔を検出前と比較して短くするなど、変化させるようにしても良い。 For example, in the above-described embodiment, as an example of setting the road surface data transmission interval according to the change in the road surface state, when the road surface state changes and when there is no change, the transmission interval is shorter than when there is no change. An example to do. This is merely an example of setting the transmission interval of road surface data, and other forms may be used. For example, the transmission interval of road surface data may be made shorter when the road surface state is unchanged than when the road surface state is changed. Even in this case, since it is possible to include the timing to increase the transmission interval, the power required for data transmission is reduced at least at the timing to increase the transmission interval, as compared with the case where the transmission interval is always constant. Is possible. Furthermore, for changes in road surface conditions, both the change time and no change time are detected, but only the change time is detected, and the road surface data transmission interval is shortened compared to before detection at the time of change, etc. It may be changed.
　また、上記実施形態では、路面状態の変化が１回検出されると、その変化に応じて路面データの送信間隔が設定されるようにしている。しかしながら、ノイズなどによって路面状態の変化が検出されることもあるため、路面状態の変化が検出されたのち、続くタイヤ回転の際にも変化した路面状態が継続した場合に、路面状態の変化に応じた送信間隔が設定されるようにしても良い。このようにすれば、ノイズ的に路面状態の変化が検出されたような場合にまでドライバに報知することを防ぐことができる。 In the above embodiment, when a change in road surface condition is detected once, the transmission interval of road surface data is set according to the change. However, since changes in the road surface condition may be detected due to noise or the like, if the changed road surface condition continues during the subsequent tire rotation after the change in the road surface condition is detected, the change in the road surface condition A corresponding transmission interval may be set. In this way, it is possible to prevent the driver from being notified until a change in the road surface state is detected in noise.
　ただし、車両運動制御については、路面状態の変化に早急に対応した制御が行われるようにする方が好ましい場合もある。したがって、報知装置２４による報知と、車両運動制御における路面状態に対応した制御が行われるタイミングを異ならせるようにしても良い。すなわち、報知装置２４による報知については、路面状態の変化が検出されて直ぐに報知を行うのではなく、変化した路面状態がタイヤ３の複数回転分継続した場合に行われるようにする。そして、車両運動制御については、路面状態の変化を検出して直ぐに変化後の路面状態に応じて車両運動制御が行われるようにしても良い。 However, as for vehicle motion control, it may be preferable to perform control corresponding to changes in road surface conditions as soon as possible. Therefore, the timing at which the notification by the notification device 24 and the control corresponding to the road surface state in the vehicle motion control are performed may be made different. That is, the notification by the notification device 24 is not performed immediately after a change in the road surface state is detected, but is performed when the changed road surface state continues for a plurality of rotations of the tire 3. And about vehicle motion control, you may make it perform vehicle motion control according to the road surface state after changing immediately after detecting the change of a road surface state.
　また、上記実施形態においては、振動検出部を構成する加速度センサ１１の検出信号から接地区間を特定し、接地区間中の検出信号における高周波成分のレベルの算出結果を路面状態が示された路面データとして用いている。しかしながら、これも振動検出部での検出信号を用いて路面状態を検出する手法の一例を示したに過ぎず、振動検出部での検出信号を用いた他の手法によって路面状態を検出しても良い。また、振動検出部を加速度センサ１１によって構成する場合を例示したが、他の振動検出を行うことができる素子、例えば圧電素子などによって振動検出部を構成することもできる。また、電源１５についても、電池に限らず、発電素子などによって構成することもできる。例えば、振動検出素子を用いれば、振動検出素子によって振動検出部を構成しつつ電源１５を構成することもできる。 Moreover, in the said embodiment, a ground contact area is identified from the detection signal of the acceleration sensor 11 which comprises a vibration detection part, and the road surface data by which the road surface state was shown by the calculation result of the level of the high frequency component in the detection signal in a ground contact area. It is used as. However, this is only an example of a method for detecting the road surface state using the detection signal at the vibration detection unit, and even if the road surface state is detected by another method using the detection signal at the vibration detection unit. good. Moreover, although the case where the vibration detection part was comprised by the acceleration sensor 11 was illustrated, the vibration detection part can also be comprised by the element which can perform another vibration detection, for example, a piezoelectric element. Further, the power source 15 is not limited to a battery, and may be configured by a power generation element or the like. For example, if a vibration detection element is used, the power supply 15 can be configured while the vibration detection unit is configured by the vibration detection element.
　また、上記実施形態の場合、受信機２１にて、路面データに基づく路面状態の変化の判定などを行う制御部としての役割を果たしている。しかしながら、これは一例を示したに過ぎず、受信機２１とは別に制御部を備えても良いし、ブレーキＥＣＵ２２などの他のＥＣＵを制御部として機能させるようにしても良い。 In the case of the above-described embodiment, the receiver 21 plays a role as a control unit that determines a change in road surface state based on road surface data. However, this is merely an example, and a control unit may be provided separately from the receiver 21, or another ECU such as the brake ECU 22 may function as the control unit.
　さらに、上記実施形態では、路面状態推定装置を車両用危険回避装置に組み込んだ場合について説明した。この車両用危険回避装置のうち路面状態の推定を行っている部分、例えば上記実施形態の場合であればタイヤマウントセンサ１および受信機２１が路面状態推定装置に相当するが、この路面状態推定装置のみの構成としても良い。 Furthermore, in the above embodiment, the case where the road surface state estimation device is incorporated in the vehicle danger avoidance device has been described. Of the vehicle danger avoidance device, the portion that estimates the road surface state, for example, in the case of the above embodiment, the tire mount sensor 1 and the receiver 21 correspond to the road surface state estimation device. It is good also as a structure only.

Claims (11)

  1. 　タイヤ（３）の裏面に取り付けられるタイヤマウントセンサであって、
    　前記タイヤの振動の大きさに応じた検出信号を出力する振動検出部（１１）と、
    　前記振動検出部の検出信号が示す振動データから路面状態を検出する信号処理部（１３）と、
    　前記路面状態が表された路面データを送信する送信部（１４）と、を有し、
    　前記信号処理部は、前記タイヤの回転に伴う前記路面状態の変化に応じて前記路面データの送信間隔を設定し、前記送信部より送信させる送信制御部（１３ｄ）を備えているタイヤマウントセンサ。     A tire mount sensor attached to the back surface of the tire (3),
    A vibration detector (11) for outputting a detection signal corresponding to the magnitude of vibration of the tire;
    A signal processor (13) for detecting a road surface state from vibration data indicated by a detection signal of the vibration detector;
    A transmission unit (14) for transmitting road surface data representing the road surface state,
    The said signal processing part is a tire mount sensor provided with the transmission control part (13d) which sets the transmission interval of the said road surface data according to the change of the said road surface state accompanying rotation of the said tire, and transmits from the said transmission part.
  2. 　前記送信制御部は、前記路面状態が変化すると、前記路面データの送信間隔を変化させる請求項１に記載のタイヤマウントセンサ。 The tire mount sensor according to claim 1, wherein the transmission control unit changes a transmission interval of the road surface data when the road surface state changes.
  3. 　前記送信制御部は、前記路面状態が変化した変化時を検出し、該変化時を検出すると、該変化時の検出前よりも前記路面データの送信間隔を短く設定する請求項１または２に記載のタイヤマウントセンサ。 The said transmission control part detects the change time when the said road surface state changed, and if this change time is detected, the transmission interval of the said road surface data will be set shorter than before the detection at the time of this change. Tire mount sensor.
  4. 　前記送信制御部は、前記変化時の検出前には前記タイヤが複数回転する毎に１回の割合で前記送信部より前記路面データを送信させ、前記変化時には前記タイヤが１回転する毎に１回の割合で前記送信部より前記路面データを送信させる請求項３に記載のタイヤマウントセンサ。 The transmission control unit causes the transmission unit to transmit the road surface data at a rate of once every time the tire rotates a plurality of times before detection at the time of the change, and 1 time for each rotation of the tire at the time of the change. The tire mount sensor according to claim 3, wherein the road surface data is transmitted from the transmission unit at a rate of times.
  5. 　前記送信制御部は、前記変化時の検出前には前記タイヤが複数回転する毎に１回の割合で前記送信部より前記路面データを送信させ、前記変化時には前記タイヤが１回転する毎に複数回の割合で前記送信部より前記路面データを送信させる請求項３に記載のタイヤマウントセンサ。 The transmission control unit causes the transmission unit to transmit the road surface data at a rate of once every time the tire rotates a plurality before the detection at the time of the change, and a plurality of times each time the tire rotates at the time of the change. The tire mount sensor according to claim 3, wherein the road surface data is transmitted from the transmission unit at a rate of times.
  6. 　前記送信制御部は、前記路面状態が変化した変化時と前記路面状態が変化していない無変化時とを検出し、前記無変化時には前記タイヤが複数回転すると前記送信部より前記路面データを送信させると共に、前記変化時には前記無変化時よりも送信間隔を短くして前記送信部より前記路面データを送信させる請求項１または２に記載のタイヤマウントセンサ。 The transmission control unit detects when the road surface state has changed and when the road surface state has not changed, and transmits the road surface data from the transmission unit when the tire rotates a plurality of times when there is no change. 3. The tire mount sensor according to claim 1, wherein the road surface data is transmitted from the transmission unit with a transmission interval shorter than that at the time of no change at the time of the change.
  7. 　前記送信制御部は、前記無変化時には前記タイヤが複数回転する毎に１回の割合で前記送信部より前記路面データを送信させ、前記変化時には前記タイヤが１回転する毎に１回の割合で前記送信部より前記路面データを送信させる請求項６に記載のタイヤマウントセンサ。 The transmission control unit causes the transmission unit to transmit the road surface data at a rate of once for each rotation of the tire at the time of no change, and at a rate of once for each rotation of the tire at the time of the change. The tire mount sensor according to claim 6, wherein the road surface data is transmitted from the transmission unit.
  8. 　前記送信制御部は、前記無変化時には前記タイヤが複数回転する毎に１回の割合で前記送信部より前記路面データを送信させ、前記変化時には前記タイヤが１回転する毎に複数回の割合で前記送信部より前記路面データを送信させる請求項６に記載のタイヤマウントセンサ。 The transmission control unit causes the transmission surface to transmit the road surface data at a rate of once every time the tire rotates a plurality of times at the time of the change, and at a rate of a plurality of times per rotation of the tire at the time of the change. The tire mount sensor according to claim 6, wherein the road surface data is transmitted from the transmission unit.
  9. 　前記信号処理部は、
    　前記タイヤの１回転中における該タイヤのうちの前記振動検出部の配置箇所と対応する部分が接地している接地区間を特定する接地区間特定部（１３ａ）と、
    　前記接地区間中における前記検出信号の高周波成分のレベルを算出する高周波レベル算出部（１３ｂ）と、を有し、
    　前記送信部は、前記高周波成分のレベルの算出結果を前記路面状態が表された路面データとして送信する請求項１ないし８のいずれか１つに記載のタイヤマウントセンサ。     The signal processing unit
    A grounding section specifying unit (13a) for specifying a grounding section in which a portion corresponding to the location of the vibration detection unit of the tire during one rotation of the tire is grounded;
    A high frequency level calculation unit (13b) for calculating a level of a high frequency component of the detection signal in the grounding section,
    The tire mount sensor according to any one of claims 1 to 8, wherein the transmission unit transmits a calculation result of the level of the high-frequency component as road surface data representing the road surface state.
  10. 　請求項１ないし９のいずれか１つに記載されたタイヤマウントセンサと、
    　車体側に備えられ、前記送信部から送信された前記路面データを受信すると共に、前記路面データに基づいて路面状態を推定する制御部（２１）を有する車体側システム（２）と、を備えた路面状態推定装置。     A tire mount sensor according to any one of claims 1 to 9,
    A vehicle body side system (2) provided on the vehicle body side, having the control unit (21) for receiving the road surface data transmitted from the transmission unit and estimating a road surface state based on the road surface data. Road surface state estimation device.
  11. 　請求項１０に記載の路面状態推定装置を含み、
    　前記車体側システムには、ドライバへの報知を行う報知装置（２５）が備えられ、
    　前記制御部は、前記報知装置を通じて、推定した前記路面状態に応じた報知を行う車両用危険回避装置。     Including the road surface state estimating device according to claim 10,
    The vehicle body side system is provided with a notification device (25) for performing notification to the driver,
    The said control part is a danger avoidance apparatus for vehicles which performs alerting | reporting according to the estimated said road surface state through the said alerting | reporting apparatus.
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CN111114550A (en) * 2018-10-30 2020-05-08 长城汽车股份有限公司 Vehicle control method and control device, vehicle and storage medium
CN111114550B (en) * 2018-10-30 2021-11-23 长城汽车股份有限公司 Vehicle control method and control device, vehicle and storage medium

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