WO2015076200A1 - Dispositif de détection de réduction de pression d'air pour des pneus d'automobile - Google Patents

Dispositif de détection de réduction de pression d'air pour des pneus d'automobile Download PDF

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Publication number
WO2015076200A1
WO2015076200A1 PCT/JP2014/080204 JP2014080204W WO2015076200A1 WO 2015076200 A1 WO2015076200 A1 WO 2015076200A1 JP 2014080204 W JP2014080204 W JP 2014080204W WO 2015076200 A1 WO2015076200 A1 WO 2015076200A1
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Prior art keywords
air pressure
tire
rotation
detecting
decrease
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PCT/JP2014/080204
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English (en)
Japanese (ja)
Inventor
高橋亨
西川健太郎
福島靖之
正木信男
若尾泰通
Original Assignee
Ntn株式会社
株式会社ブリヂストン
高橋亨
西川健太郎
福島靖之
正木信男
若尾泰通
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Application filed by Ntn株式会社, 株式会社ブリヂストン, 高橋亨, 西川健太郎, 福島靖之, 正木信男, 若尾泰通 filed Critical Ntn株式会社
Publication of WO2015076200A1 publication Critical patent/WO2015076200A1/fr

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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
    • B60C23/00—Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements
    • B60C23/06—Signalling devices actuated by deformation of the tyre, e.g. tyre mounted deformation sensors or indirect determination of tyre deformation based on wheel speed, wheel-centre to ground distance or inclination of wheel axle
    • B60C23/061—Signalling devices actuated by deformation of the tyre, e.g. tyre mounted deformation sensors or indirect determination of tyre deformation based on wheel speed, wheel-centre to ground distance or inclination of wheel axle by monitoring wheel speed
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M17/00—Testing of vehicles
    • G01M17/007—Wheeled or endless-tracked vehicles
    • G01M17/02—Tyres
    • G01M17/025—Tyres using infrasonic, sonic or ultrasonic vibrations

Definitions

  • the present invention relates to an automobile tire pressure drop detection device that detects the pressure state of an automobile tire while the vehicle is running and informs the driver of a safety warning or a tire pressure state.
  • Patent Document 1 proposes a method of detecting a decrease in the internal pressure of a tire by relatively comparing the wheel speeds of the tires mounted on each wheel of the vehicle.
  • Patent Document 2 proposes a method for determining a tire condition by performing frequency analysis on the output of a wheel speed sensor and calculating a contact length obtained by removing a vehicle speed component from a high frequency component.
  • Patent Document 3 when the resonance frequency that is the tire pressure evaluation value is obtained, it is stored separately for each wheel speed, outside air temperature, and road type, and the resonance frequency obtained under the same conditions as before A method for determining a decrease in tire air pressure by comparison is presented.
  • Patent Document 4 proposes a high-resolution rotation detection device provided with a function of multiplying a signal by attaching a rotation detection device to a wheel bearing of an automobile.
  • Patent Document 5 proposes a rotation detection device capable of detecting an absolute angle by attaching a rotation detection device to a wheel bearing of an automobile.
  • Patent Document 6 presents a method for estimating a slip ratio and the like from a tire rotation sensor signal, and also presents a method for detecting the rotation synchronization component by averaging the rotation signal of the tire over several rotations.
  • TPMS Transire Pressure Monitoring System
  • the TPMS is made redundant without detecting so much cost and detecting the tire pressure state. ing.
  • tire pressure is automatically detected to alert the driver. desired.
  • the object of the present invention is to detect the air pressure state of the tire from the signal of the rotation sensor of the running wheel, it is not necessary to provide a special sensor on the rotation side member, without significantly increasing the cost,
  • An object of the present invention is to provide an automobile tire pressure drop detection device that can be mounted on a vehicle.
  • An apparatus for detecting a decrease in air pressure of an automobile tire is based on a rotation sensor 2 that detects the rotation of a wheel 1 and a rotation signal detected by the rotation sensor 2 so as to measure the speed of the automobile.
  • an air pressure state determination unit 4 that estimates the air pressure state of the tire 1a and outputs air pressure information.
  • variation of the rotational speed synchronized with rotation arises when the tire 1a rolls on the road surface.
  • the rotation sensor 2 is installed on a wheel bearing 30 or a drive shaft, and detects the rotation of the wheel 1.
  • the signal processing unit 3 uses the rotation signal detected by the rotation sensor 2 to extract a rotational speed fluctuation pattern synchronized with the rotation of the tire 1a that changes as described above during traveling.
  • the air pressure state determination unit 4 obtains a cross-correlation pattern between the rotational speed fluctuation pattern thus obtained and the reference rotational speed fluctuation pattern, and based on this cross-correlation pattern or the reference rotational speed fluctuation pattern.
  • the air pressure state of the tire 1a is estimated and the air pressure information is output based on the comparison between the autocorrelation pattern and the extracted autocorrelation pattern of the rotational speed fluctuation pattern. Since the air pressure state of the tire 1a can be detected during traveling using the signal acquired from the rotation sensor 2, it is not necessary to provide a special sensor. Therefore, the air pressure drop detection function of the tire 1a can be mounted on the vehicle without significantly increasing the cost.
  • the air pressure drop detection function can be mounted on the vehicle.
  • a filter process is performed by a low-pass filter (LPF) or a high-pass filter (HPF), and the tire is generated from the rotation signal as the rotation speed data. You may make it extract the component resulting from the tread pattern of 1a.
  • LPF low-pass filter
  • HPF high-pass filter
  • the air pressure state determination unit may estimate a tire air pressure state based on a peak value of the cross-correlation pattern.
  • the air pressure state determination unit 4 may estimate the air pressure state of the tire 1a based on the phase ⁇ of the cross-correlation pattern.
  • the cross-correlation pattern changes depending on the air pressure, and the peak value and the phase ⁇ of the peak position also change. Based on the peak value or the phase ⁇ of the cross-correlation pattern, the air pressure state of the tire 1a can be easily estimated.
  • the signal processing unit 3 subjects the rotation speed fluctuation pattern synchronized with the rotation to a rotation signal over a plurality of rotations of the rotation sensor 2 by performing an averaging process or an integration process synchronized with the rotation, You may get it.
  • the rotation signal data for one rotation is affected by road surface irregularities, etc., but the rotation signal for a period of a certain number of rotations is collected and averaged or integrated to extract an arbitrary rotation speed fluctuation pattern.
  • the influence of road surface unevenness is eliminated.
  • the rotation synchronization component is integrated or averaged and extracted, a very slight fluctuation in the rotation speed can be detected, so that the information on the air pressure of the tire 1a can be detected and notified with high accuracy.
  • the signal processing unit 3 may perform the process of extracting the fluctuation of the rotational speed synchronized with the rotation in a traveling speed range selected from one or more set traveling speed ranges. . Since the occurrence state of the rotational speed changes depending on the state of the tire 1a, it is affected by the traveling speed. That is, the rotational speed fluctuation component exhibits frequency characteristics due to the transmission characteristics of the tire 1a, and its phase and amplitude vary depending on the traveling speed. Therefore, when extracting the rotational speed variation pattern, it is desirable to process using a signal in a state where the rotational speed is in a specific range.
  • the signal processing unit 3 performs the extraction process for each of a plurality of travel speed ranges, and the air pressure state determination unit 4 performs an air pressure state estimation process for each speed range data, From the results of the plurality of estimation processes, the air pressure of the tire 1a may be indicated in three stages: normal, air pressure drop, and abnormality.
  • the normal pressure is equal to or higher than the first air pressure threshold value and indicates a normal tire pressure.
  • the air pressure drop is lower than the first air pressure threshold, but above the second air pressure threshold and not so low as to require immediate air filling, but indicates an air pressure at which air filling is desirable. .
  • An anomaly indicates an air pressure below the second air pressure threshold and low enough to require immediate air filling.
  • the rotation sensor 2 includes a magnetic sensor 2b and a magnetic encoder 2a having a detected pole detected by the magnetic sensor 2b or a pulsar gear, and outputs fluctuations in magnetic strength due to rotation as an analog signal. It is good also as a structure. If an analog signal output with rotation is analyzed, fluctuations in the rotation speed can be extracted from the distortion of the waveform included in the signal, so that the same processing as in the case of pulse output is possible.
  • the magnetic sensor 2b is preferably a magnetic sensor as the rotation sensor 2 installed in an environment that is more resistant to temperature changes and dirt than the optical sensor and is easily contaminated.
  • the rotation sensor 2 outputs a magnetic encoder 2a or a pulser gear having a magnetic sensor 2b and a detected pole detected by the magnetic sensor 2b, and a rotation pulse for multiplying a detection signal of the magnetic sensor 2b.
  • the structure provided with the multiplication circuit 2ca may be sufficient.
  • a rotation sensor 2 mounted on the wheel 1 having sufficient detection accuracy and sufficient spatial resolution is used. It is desirable.
  • the rotation sensor 2 that combines the magnetic encoder 2a or the pulser gear and the magnetic sensor 2b as described above, and multiplies the detected magnetic field signal to increase the resolution is resistant to inferior environments such as temperature changes and dirt, and performs, for example, one rotation. Since it has a rotational resolution of 100 pulses or more, it is suitable for this application.
  • the rotational fluctuation component in the low-speed running state can be detected with high resolution, and the detection accuracy of the change in the air pressure of the tire 1a is increased.
  • an air pressure estimation result utilization means 17 for informing the driver or changing the vehicle control state based on the air pressure state information of the tire estimated by the air pressure state determination unit 4.
  • the tire air pressure estimation result utilization means 17 is provided, for example, in the computer 16 of the vehicle that is higher than the air pressure state determination unit 4.
  • the tire pressure estimation result utilization means 17 has one of the following functions.
  • the air pressure estimation result utilizing means 17 may be configured to cause the notifying means 19 provided in the driver's seat to notify the air pressure state information of the tire 1a estimated by the air pressure state determining unit 4.
  • the notification means 19 is, for example, an image display device 19b such as a liquid crystal display device provided on the console of the driver's seat or a display lamp 19a such as a warning lamp. A warning lamp is lit according to the air pressure state to prompt the driver to check, adjust and check the air pressure.
  • the air pressure estimation result utilization means 17 changes the control parameter of the vehicle control computer such as the vehicle control ECU 22 based on the air pressure state information of the tire 1a estimated by the air pressure state determination unit 4, and according to the capability of the tire 1a. It is good also as a structure which performs the defined safety control.
  • parameters of the safety control system 22a such as vehicle attitude control may be changed according to the detected air pressure state information of the tire 1a, and the safety control system 22a may be adjusted in consideration of the ability of the tire 1a.
  • vehicle control in consideration of the ability of the tire 1a is possible, appropriate driving assistance and safety control can be performed according to the traveling conditions, and traffic accidents can be prevented.
  • the air pressure estimation result utilization means 17 is determined based on the air pressure state information of the tire 1 a estimated by the air pressure state determination unit 4 and the driving weather obtained from the weather information obtaining means 25. It is good also as a structure which issues a warning at the time of the weather. Depending on the estimated air pressure of the tire 1a, a warning is not issued when the weather is fine, but a warning is issued during rainy weather when slipping is likely to occur. You can also call attention.
  • the air pressure estimation result utilization means 17 is mounted on the vehicle when a decrease in air pressure of a predetermined value or more is confirmed within a predetermined time based on the air pressure state estimated by the air pressure state determination unit 4.
  • the computer 16 may be configured to have a function of transmitting tire pressure information via a communication line 18 to a terminal of a predetermined sales office where vehicle inspection or tire replacement is possible.
  • an abnormality such as puncture has occurred in the tire 1a.
  • information is transmitted through the communication line 18 of the vehicle at the same time as the notification by the display lamp 19a serving as a warning lamp, and the inspection is performed through the sales office 20 such as a vehicle dealer or a service store as necessary. ⁇ Encourage exchanges. Thereby, inventory check of the tire 1a etc. in the sales office 20 is performed at an early stage, and prompt and appropriate inspection and replacement can be expected.
  • FIG. 1 is a block diagram showing a conceptual configuration of an automotive tire pressure drop detection device according to a first embodiment of the present invention. It is a block diagram which shows the conceptual structure of the signal processing unit of the same air pressure fall detection apparatus. It is a block diagram which shows the conceptual structure of the air pressure state judgment unit of the same air pressure fall detection apparatus.
  • FIG. 19B is a perspective view of the rotation sensor of FIG. 19A. It is sectional drawing which shows the 2nd example of the rotation sensor which the air pressure fall detection apparatus of the tire uses.
  • FIG. 20B is a perspective view of the rotation sensor of FIG. 20A. It is a block diagram which shows an example of the multiplication circuit in a rotation sensor. It is explanatory drawing of the magnetic sensor using the same multiplication circuit. It is composition explanatory drawing which shows the example of the absolute angle rotation sensor used as the rotation sensor.
  • (A)-(E) are explanatory drawings of the magnetic pole arrangement and detection signals of the rotation sensor.
  • (A)-(E) are explanatory drawings of a magnetic pole arrangement and detection signal processing example of the same rotation sensor.
  • an automobile tire air pressure drop detecting device 5 is a rotation sensor 2 for detecting the rotational speed of a wheel 1 having a tire 1a to be subjected to air pressure drop detection, and is a wheel bearing or drive. It has a rotation sensor 2 installed on a shaft outer ring or the like and a signal processing unit 3 for processing an output rotation signal.
  • the tire pressure drop detection device 5 also has a pneumatic state determination unit 4 that estimates the pneumatic state of the tire 1 a using the output of the signal processing unit 3.
  • the signal processing unit 3 is a means for extracting the fluctuation of the rotation speed synchronized with the rotation from the rotation signal detected by the rotation sensor 3 and extracting the rotation speed fluctuation pattern synchronized with the rotation from the extracted fluctuation of the rotation speed.
  • the air pressure of the tire 1a changes, the shape and area of the ground contact surface of the tire and the position where the tire 1a steps on the road surface change, so the rotational speed variation pattern changes. This is detected by the air pressure state determination unit 4 and information on the air pressure state of the tire 1a is output.
  • the signal processing unit 3 and the air pressure state determination unit 4 constitute an air pressure drop detecting device main body 15.
  • the air pressure decrease detection device main body 15 may be an independent ECU, or may be provided as a part of the ECU that controls the entire vehicle.
  • FIGS. 13 to 18 illustrate wheel bearings with rotation sensors, which will be described later.
  • FIG. 2 shows a conceptual configuration of the signal processing unit 3.
  • the rotational speed of the running wheel 1 is measured by the rotational speed discriminating unit 5a using the rotational signal detected by the rotational sensor 2, and the fluctuation of the rotational speed synchronized with the rotation of the wheel 1, that is, one revolution.
  • the rotation fluctuation pattern for each rotation is extracted by the rotation fluctuation pattern extraction unit 6.
  • a detection target such as a magnetic encoder used for the rotation sensor 2 includes a pitch error due to manufacturing variations. Therefore, the rotation speed fluctuation pattern in the normal state in the initial state is stored in the reference speed pattern storage unit 7 as the reference speed pattern P0, and a minute error component superimposed on the rotation signal of the rotation sensor 2 is corrected for error. The correction is performed by the unit 8.
  • filter processing is performed by a low-pass filter (LPF) or a high-pass filter (HPF) (both not shown), Components derived from the shape and tread pattern of the tire 1a are extracted.
  • LPF low-pass filter
  • HPF high-pass filter
  • rotation signals for a period of a certain number of rotations are collected and averaged or integrated to extract an arbitrary rotation speed fluctuation pattern.
  • the rotation synchronization component is averaged and detected from the rotation signal of the wheel 1 over several rotations.
  • the extraction of the rotation variation pattern will be described. Since the occurrence state of the rotational speed changes depending on the state of the tire 1a, it is affected by the traveling speed. That is, the rotational speed fluctuation component exhibits frequency characteristics due to the transmission characteristics of the tire 1a, and its phase and amplitude vary depending on the traveling speed. Therefore, when extracting the rotational speed variation pattern, it is desirable to perform processing using a signal in a state where the rotational speed is in a specific range.
  • the signal processing unit 3 is provided with a rotational speed discriminating unit 5a, so A speed discrimination function is provided.
  • the rotational speed fluctuation patterns are classified by a plurality of rotational speed regions (rotational speed levels). That is, a configuration is adopted in which a rotational speed variation pattern is extracted for each rotational speed region, the air pressure state of the tire 1a is determined in each region, and a comprehensive determination is made from the result.
  • a rotational speed variation pattern is extracted for each rotational speed region, the air pressure state of the tire 1a is determined in each region, and a comprehensive determination is made from the result.
  • the rotation sensor 2 is composed of a magnetic encoder 2a and a magnetic sensor 2b, and the magnetic encoder 2a has N and S magnetic poles 2aa which are detected portions alternately. It is applied when it is a sensor.
  • the rotation sensor 2 will be specifically described later.
  • the output of the rotation sensor 2 is rotated by the rotation speed of the detected portion (the magnetic pole 2aa or the individual teeth of the detection gear) or the required time for the rotation of the tire for one rotation of the tire.
  • An averaging unit 6a of the fluctuation pattern extraction unit 6 averages and a rotation speed fluctuation pattern that becomes tire characteristics is obtained by the extraction unit 6b. Not only taking a simple average but also taking a weighted average that puts more weight on the previous value than the past value, you can always get the latest tire characteristics and follow the tire characteristics over time .
  • the passing speed or the passing time of the detected portion (the individual teeth of the magnetic pole 2aa or the detection gear) for a plurality of rotations.
  • the rotational speed fluctuation pattern which is the tire characteristic shown in FIG. 6B is obtained.
  • the vertical axis represents the passing speed or the time required for passing through each detected part
  • the horizontal axis represents the time (corresponding to each detected part).
  • the air pressure state determination unit 4 registers the rotation speed fluctuation pattern (Pref) in a normal state (initial state) in the reference pattern storage unit 13 as a reference pattern, and detects the detected rotation speed fluctuation. Comparison with pattern (Pobs), auto-correlation pattern (Pcorr1) of detected rotational speed fluctuation pattern (Pref), detected rotational speed fluctuation pattern (Pobs) and reference rotational speed fluctuation pattern (Pref) The air pressure drop is determined from the comparison with the cross-correlation pattern (Pcorr2) of the “reference pattern”.
  • a reference value may be provided for the rotation sensor 2 to detect a correlation value or a cross-correlation pattern between the rotation speed fluctuation pattern and the reference speed pattern during traveling with the rotation phase matched.
  • the rotation sensor 2 having a Z-phase signal zero-phase signal
  • a resolver or other absolute angle sensor may be used.
  • the correlation value CV between the reference pattern (Pref) and the detected rotational speed fluctuation pattern (Pobs) is smaller than an appropriately set threshold value, it may be determined that the air pressure has decreased. At this time, the air pressure decrease degree is estimated according to the magnitude of the difference between the correlation value CV and the set threshold value.
  • the air pressure decreases. You may judge. At this time, the degree of air pressure drop is estimated according to the magnitude of the phase difference ⁇ .
  • the correlation value between the autocorrelation pattern (Pcorr1) of the reference pattern and the autocorrelation pattern (Pcorr3) of the detected rotational speed fluctuation pattern is smaller than the set threshold value, it is determined that the air pressure has decreased. May be.
  • a rotation variation pattern when the air pressure is normal may be stored in the reference pattern.
  • a change from the reference state including information such as an inherent error pattern of the rotation sensor 2 and an unbalance of the tire 1a may be stored. Can be detected, and the detection sensitivity can be further increased.
  • the reference pattern changes when the tire 1a or the wheel is replaced, the reference pattern is updated.
  • This state is a state in which it is determined that the tire type is different, so if the state suddenly changes during traveling, puncture is suspected, otherwise puncture or tire replacement has been performed, etc.
  • determination and processing are performed by the air pressure estimation result utilization means 17 described later together with FIG.
  • the rotation sensor 2 mounted on the wheel 1 has sufficient detection accuracy and sufficient spatial resolution. desirable. For example, at least 0.5% of the rotational speed fluctuation can be detected and the number of pulses per rotation is 40 or more. In order to acquire sufficient data at the time of low-speed rotation including a higher-order rotation fluctuation component, it is desirable to further increase the resolution of the rotation sensor 2. Considering the structure such as the block size of the tire 1a, it is desirable that the number of output pulses per rotation of the rotation sensor 2 be at least 100 or more so as to ensure a resolution with a contact length of about 20 mm.
  • the output of the rotation sensor 2 is not necessarily a pulse output, and may be an analog signal. If an analog signal output with rotation is analyzed, fluctuations in the rotation speed can be extracted from the distortion of the waveform included in the signal, so that the same processing as in the case of pulse output is possible. In particular, when the resolution (multiplication capability) of the rotation pulse is low, it is desirable to execute signal processing with high resolution by actively using analog signals.
  • FIGS. 9A and 9B show the comparison results with the rotational speed fluctuation patterns of 0.20 MPa and 0.14 MPa, respectively, with the air pressure of 0.23 MPa as a reference. It can be seen that the phase of the rotational speed fluctuation pattern changes due to the difference in air pressure.
  • 10 (a) and 10 (b) show cross-correlation patterns based on 0.23 MPa.
  • 10A shows a cross-correlation pattern of 0.20 MPa based on 0.23 MPa3
  • FIG. 10B shows a cross-correlation pattern of 0.14 MPa based on 0.23 MPa.
  • the cross-correlation pattern differs depending on the air pressure.
  • the phase of the peak position in the cross-correlation pattern of 0.14 MPa is different from the phase of the peak position in the cross-correlation pattern of 0.20 MPa.
  • FIG. 11 shows a schematic diagram of changes in correlation value CV and phase difference ⁇ due to the difference in air pressure created from these test data.
  • the response to the change in the rotational speed pattern will be described. Since the occurrence state of the rotational speed changes depending on the state of the tire 1a, it is affected by the traveling speed.
  • the portions within the elliptical dotted lines of the waveforms shown in FIGS. 12 (a) to 12 (c) are the speed fluctuation waveforms observed at the rotational position where the rotational fluctuation occurs, as shown in (a) to (c).
  • the waveform changes according to the running speed. That is, the rotational speed fluctuation component exhibits frequency characteristics due to the transmission characteristics of the tire 1a, and its phase and amplitude vary depending on the traveling speed.
  • the rotational speed selector 5a is provided in the signal processing unit 3 (FIG. 2). By providing, a function for discriminating the rotational speed is provided.
  • the rotational speed variation pattern is classified by a plurality of rotational speed regions (rotational speed levels). That is, a reference rotational speed fluctuation pattern as a comparison target is prepared for each rotational speed region, and the air pressure state is determined in each region, and comprehensive determination is made based on the result.
  • a reference rotational speed fluctuation pattern as a comparison target is prepared for each rotational speed region, and the air pressure state is determined in each region, and comprehensive determination is made based on the result.
  • a method of using the detected information on the decrease in air pressure of the tire 1a will be described with reference to FIG.
  • the air pressure state determination unit 4 (FIG. 3) of the air pressure lowering device main body 15
  • the air pressure for notifying the driver or changing the vehicle control state based on the information on the air pressure state of the tire 1a estimated by the air pressure state determination unit 4 (FIG. 3) of the air pressure lowering device main body 15, the air pressure for notifying the driver or changing the vehicle control state.
  • An estimation result utilization means 17 is provided.
  • the air pressure estimation result utilization means 17 is provided in the computer 16 of the vehicle that is higher than the air pressure state determination unit 4, for example.
  • the tire pressure state determination unit 4 has, for example, one of the following functions.
  • the detected tire air pressure state is transmitted from the air pressure state determining unit 4 of the air pressure lowering device main body 15 to the host computer 16 of the vehicle, and the air pressure estimation result using means 17 provided in the host computer 16 or the like changes the air pressure state.
  • the notification means 19 is notified.
  • the notification means 19 is, for example, a display lamp 19a such as a driver's seat warning lamp or an image display device 19b such as a liquid crystal display device. These indicator lamps 19a such as warning lamps are turned on to display a caution on the image display device 19b, prompting the driver to check, adjust and check the air pressure.
  • the air pressure estimation result utilization means 17 further transmits information to a terminal of a sales office 20 such as a vehicle dealer or a service store through the vehicle communication line 18 when a decrease in air pressure of a certain level or more is confirmed within a set fixed time. If necessary, adjustment and inspection are promoted through the sales office 20 such as the service store.
  • a sales office 20 such as a vehicle dealer or a service store
  • an abnormality such as puncture has occurred in the tire 1a.
  • information is transmitted through the communication line 18 of the vehicle at the same time as the notification by the display lamp 19a serving as a warning lamp, and the inspection is performed through the sales office 20 such as a vehicle dealer or a service store as necessary. ⁇ Encourage exchanges. Thereby, inventory check of the tire 1a etc. in the sales office 20 is performed at an early stage, and prompt and appropriate inspection and replacement can be expected.
  • the air pressure estimation result utilization means 17 gives a warning at the time of a predetermined weather based on the air pressure state information of the tire 1a estimated by the air pressure state determination unit 4 and the driving weather obtained from the weather information acquisition means 25. You may make it emit. For example, depending on the detected air pressure state, a warning is not issued in fine weather but a warning is issued during driving in rainy weather. . If it is determined that the state is particularly dangerous, a function of automatically limiting the traveling speed may be provided.
  • the weather information acquisition means 25 is a means for obtaining information from a radio, television, or other weather information communication means mounted on the vehicle, or a sensor (not shown) for detecting the weather.
  • the parameters of the safety control system 22a such as the vehicle attitude control provided in the vehicle control computer such as the vehicle control ECU 22 that controls the operation of the vehicle are changed according to the detected air pressure state, and the performance of the tire 1a is reduced.
  • the safety control system 22a may be adjusted so as to perform safety control determined in consideration.
  • the air pressure state of the tire 1a can be detected from the signal of the rotation sensor 2 of the running wheel 1a, it is not necessary to provide a special sensor on the rotation side member. Therefore, it can be mounted on a vehicle without significantly increasing the cost.
  • ⁇ In the past, there was a possibility that the air pressure drop could be overlooked or could not be checked due to visual inspection or inspection using a dedicated measuring instrument, but since it was detected using the rotation sensor 2 of the vehicle, an appropriate warning was sent Can promote safety confirmation and realize preventive safety.
  • the vehicle can issue a warning by the detection signal, so that it is possible to perform a driving operation such as reducing the speed.
  • a driving operation such as reducing the speed.
  • Vehicle control that takes air pressure into consideration is possible, so appropriate driving assistance and safety control can be performed according to driving conditions.
  • - Compared with a decrease in the average value (dynamic radius) of the rotation speed, a decrease in air pressure can be estimated and warned more accurately.
  • -By integrating or averaging the rotation synchronization components and extracting them very slight fluctuations in the rotation speed can be detected, so that a decrease in the air pressure of the tire 1a can be accurately detected and notified.
  • -By combining with the rotation sensor 2 having a higher resolution the rotational fluctuation component in the low-speed traveling state can be detected with a high resolution, and the detection accuracy of the air pressure state is increased.
  • detection of wheels from the rotational speed fluctuation pattern may include tire wear detection, tire abnormal state detection, tire type determination, etc.
  • the information extraction process is a deviation / deviation amount from the stored initial state (basic state).
  • the phenomenon to be detected is a shift that occurs in a similar manner from the basic state.
  • the rotation sensor 2 is a radial type magnetic type, and includes an annular magnetic encoder 2a that is a target, and a magnetic sensor 2b that faces the outer peripheral surface of the magnetic encoder 2a and detects the magnetism of the magnetic encoder 2a. .
  • the magnetic encoder 2a has N and S magnetic poles 2aa alternately, and outputs a sine wave rotation signal from the magnetic sensor 2b. This sinusoidal rotation signal is shaped into a rectangle by the signal processing means 2c and output as a rectangular wave pulse signal.
  • the signal processing means 2c may have a multiplication circuit 2ca, and in that case, outputs a multiplied high-resolution rotation signal.
  • the magnetic encoder 2a may include a magnetic pole 2ab for detecting the Z phase (zero phase) in one place on the circumference, aligned in the axial direction with the magnetic pole 2aa.
  • the magnetic sensor 2b In addition to the sensor unit 2ba for detecting the N and S alternating magnetic poles 2aa, a sensor unit 2bb for detecting the magnetic pole 2ab for detecting the Z phase is provided. This sensor unit 2bb outputs a Z-phase (zero-phase) signal once in one rotation.
  • the rotation sensor 2 is an axial magnetic type, and an annular magnetic encoder 2a and a magnetic sensor 2b face each other in the axial direction.
  • the magnetic encoder 2a is attached to a flange portion of a sensor attachment ring 2d having an L-shaped cross section.
  • Other configurations are the same as the radial type rotation sensor 2 shown in FIGS. 19A and 19B.
  • the radial type rotation sensor 2 may also be provided with a zero-phase magnetic pole and sensor unit, and a multiplier circuit, as described above.
  • FIGS. 20A and 20B all show a rotation sensor 2 having a magnetic encoder 2a.
  • the rotation sensor 2 is a so-called pulsar ring (not shown) whose target is made of a gear-type magnetic material, so-called. It may be a detection gear. In that case, the magnetic sensor detects the teeth of the pulsar ring and outputs a rotation signal.
  • the magnetic rotation sensor 2 using the magnetic encoder 2a and the gear-type pulsar ring is resistant to inferior environments such as temperature changes and dirt. In the case of the magnetic type, it is difficult to provide the magnetic poles more finely than in the optical type. However, if the multiplication circuit 2ca is provided, a rotation signal having a resolution necessary for detecting the rotation speed fluctuation pattern can be obtained.
  • FIG. 21 shows an example of the multiplier circuit 2ca.
  • the multiplication circuit 2ca has a phase difference of 90 degrees ( ⁇ / 4) when the pitch ⁇ of one magnetic pole pair of the magnetic encoder 2ba is one period as shown in FIG.
  • the multiplication circuit 2ca includes a signal generation means 41, a fan detection means 42, a multiplexer means 43, and a fine interpolation means 44.
  • the signal generating means 41 has the same amplitude A0 and the same average value C0 from the two-phase signals sin ⁇ and cos ⁇ which are the outputs of the magnetic sensor elements 2baa and 2bab of the magnetic sensor 2b, and m is n or less.
  • Is a means for generating 2 m ⁇ 1 signals si that are successively shifted in phase by 2 ⁇ / 2 m ⁇ 1 from each other, where i is a positive integer of 1 to 2 m ⁇ 1 .
  • the sector detection means 42 generates m digital signals bn-m + 1, bn-m + 2, ..., bn-1, bnb encoded to define 2m equal sector Pi ⁇ ⁇ ⁇ . This is means for detecting 2m sector Pi delimited by 2m-1 signals si.
  • the multiplexer means 43 is controlled by the m digital signals bn-m + 1, bn-m + 2,..., Bn-1, bn generated from the sector detecting means 42, and is generated from the signal generating means 41.
  • 2m-1 of the above-mentioned signals si are processed, and the amplitude is constituted by a portion of the series of 2m-1 of the signals si between the average value C0 and the first threshold value L1.
  • the fine interpolation means 44 is coded to subdivide each of the 2 m sectors Pi at an angle 2 ⁇ / 2 m into 2 nm identical subsectors at an angle 2 ⁇ / 2n to obtain the desired resolution.
  • the (n ⁇ m) digital signals b1, b2,..., Bn-m ⁇ 1, bn-m (here b1, b2,..., B8, b9) are multiplied by rotation pulses.
  • FIG. 23, FIG. 24 (A) to (E) and FIG. 25 (A) to (E) show an example in which the rotation sensor 2 is an absolute angle detection type.
  • the magnetic encoder 2a is provided with two magnetic pole rows 2aA and 2aB, the number of magnetic pole pairs of one magnetic pole row 2aA is P, and the number of magnetic pole pairs of the other magnetic pole row 2aB is P + n. Therefore, there is a phase difference of n magnetic pole pairs per rotation between the magnetic pole arrays 2aA and 2aB, and the phases of the detection signals of the magnetic sensors 2ba and 2bb corresponding to these magnetic pole arrays 2aA and 2aB are Each time it rotates 360 / n degrees, it matches.
  • the phase difference detection means 2cb constituting the signal processing means 2c outputs a phase difference signal as shown in FIG. 24 (E) based on the detection signals of the magnetic sensors 2ba and 2bb.
  • the angle calculation means 2cc provided in the subsequent stage corrects the phase difference obtained by the phase difference detection means 2cb and then performs a process of converting into an absolute angle according to a preset calculation parameter.
  • FIGS. 24A and 24B show examples of magnetic pole patterns of both magnetic pole arrays 2aA and 2aB.
  • FIGS. 24C and 24D show waveforms of detection signals of the magnetic sensors 2ba and 2bb corresponding to the magnetic pole arrays 2aA and 2aB.
  • two magnetic pole pairs of the magnetic pole array 2aB correspond to three magnetic pole pairs of the magnetic pole array 2aA, and the absolute position within this section can be detected.
  • FIG. 25E shows a waveform diagram of the output signal of the phase difference obtained by the phase difference detection means 2cb of FIG. 23 based on the detection signals of FIGS. 24C and 24D.
  • phase difference signals detected by the phase difference detecting means 2cb are affected by the magnetic interference and noise of the magnetic pole arrays 2aA and 2aB, they are actually distorted. A waveform with Therefore, the angle calculation means 2cc corrects the angle correction means 2cca to calculate an absolute angle with high detection accuracy.
  • the wheel bearing 30 shown in FIGS. 13 and 14 is a third generation inner ring rotation type and is for driving wheel support, and shows an example in which the rotation sensor 2 is provided in the center of the double row.
  • the wheel bearing 30 includes an outer member 31 having a double row rolling surface 33 formed on the inner periphery, an inner member 32 having a rolling surface 34 opposed to each of the rolling surfaces 33, and these outer members.
  • the rolling member 35 of the double row interposed between the rolling surfaces 33 and 34 of the direction member 31 and the inward member 32 is provided, and a wheel is rotatably supported with respect to a vehicle body.
  • the wheel bearing 30 is a double-row outward angular ball bearing type, and the rolling elements 35 are formed of balls and are held by a cage 36 for each row.
  • the inner member 32 includes a hub wheel 32a and an inner ring 32b fitted to the outer periphery of the inboard side end of the hub wheel 32a.
  • the rolling surface 34 is provided on the outer periphery of each wheel 32a, 32b. . Both ends of the bearing space between the outer member 31 and the inner member 32 are sealed by seals 37 and 38, respectively.
  • the encoder 2 a of the rotation sensor 2 is provided on the outer periphery between the rolling surfaces 34 of the inner member 32, and the magnetic sensor 2 b facing the encoder 2 a is provided on the outer member 31. It is installed in the provided sensor mounting hole 40 in the radial direction.
  • the rotation sensor 2 is, for example, the radial type described above with reference to FIG.
  • the wheel bearing 30 is a third generation inner ring rotating type and for driving wheel support
  • the rotation sensor 2 is provided at the inboard side end.
  • the rotation sensor 2 is of the axial type described above with reference to FIGS. 20A and 20B.
  • the slinger that is press-fitted and fixed to the outer peripheral surface of the inner member 32 in the seal 38 at the inboard side end also serves as the sensor support ring 2d in the example of FIGS. 20A and 20B.
  • the magnetic sensor 2 b is resin-molded in a ring-shaped metal case 39 and fixed to the outer member 31 via the metal case 39. Other configurations are the same as those shown in FIGS.
  • 17 and 18 show an example in which the wheel bearing 30 is a third generation inner ring rotating type and for supporting a driven wheel, and the rotation sensor 2 is provided at the inboard side end.
  • the end face opening at the inboard side end portion of the outer member 31 is covered with a cover 29, and the magnetic sensor 2 b of the rotation sensor 2 is attached to the cover 29.
  • Other configurations and operational effects are the same as those of the example shown in FIGS.
  • the air pressure drop detecting device for automobile tires of the present invention can be widely applied from small cars such as passenger cars and taxis to large cars such as trucks, trailers and buses.
  • small cars such as passenger cars and taxis
  • large cars such as trucks, trailers and buses.
  • the most preferable form is application to large vehicles such as trucks, trailers and buses.
  • These automobiles require passengers and cargo to be transported safely and efficiently, so it is important to always keep the vehicle in a normal state.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

L'invention concerne un dispositif de détection de réduction de pression d'air en mesure de détecter l'état de la pression d'air d'un pneu d'après des signaux de rotation pour une roue en cours de déplacement, ledit dispositif ne nécessitant pas la mise en œuvre d'un capteur spécial sur un élément côté rotation. Le dispositif comporte : un capteur de rotation (2) qui détecte des signaux de rotation pour une roue (1) de manière à pouvoir mesurer la vitesse de l'automobile ; une unité de traitement de signaux (3) qui extrait une fluctuation au niveau de la vitesse de rotation synchronisée par rapport à la rotation, d'après les signaux de rotation détectés par ce capteur de rotation (2), et qui extrait un modèle de fluctuation de vitesse de rotation synchronisée par rapport à la rotation, d'après cette fluctuation extraite au niveau de la vitesse de rotation ; et une unité de détermination de l'état de pression d'air (4) qui estime l'état de la pression d'air d'un pneu (1a) et qui fournit des informations se rapportant à la pression d'air, en fonction d'un modèle de corrélation croisée entre un modèle de fluctuation de vitesse de rotation de référence et le modèle de fluctuation de vitesse de rotation extraite.
PCT/JP2014/080204 2013-11-21 2014-11-14 Dispositif de détection de réduction de pression d'air pour des pneus d'automobile WO2015076200A1 (fr)

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JP2013-241128 2013-11-21
JP2013241128A JP6425883B2 (ja) 2013-11-21 2013-11-21 自動車用タイヤの空気圧低下検知装置

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JP6509575B2 (ja) * 2015-02-10 2019-05-08 Ntn株式会社 車両の車輪回り走行影響情報検出装置

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JPS62149503A (ja) * 1985-12-24 1987-07-03 Nippon Soken Inc 車輪の空気圧検出装置
JP2000255230A (ja) * 1999-02-26 2000-09-19 Continental Ag 空気タイヤの緊急時走行状態を検出する方法と装置
JP2005170065A (ja) * 2003-12-05 2005-06-30 Hitachi Ltd 車両情報メモリエリアを持った無線タグ、車両情報メモリエリアを持った無線タグに読み書きする装置、車両情報メモリエリアを持った無線タグに読み書きする方法、車両情報メモリエリアを持った無線タグに読み書きする装置を備えた車両
JP2005186702A (ja) * 2003-12-24 2005-07-14 Bridgestone Corp タイヤ及びタイヤ摩耗状態推定方法とその装置
JP2006131137A (ja) * 2004-11-08 2006-05-25 Denso Corp 車両用信号処理装置
WO2010147004A1 (fr) * 2009-06-15 2010-12-23 Ntn株式会社 Système de contrôle de la pression d'air de pneumatique

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JP2001195697A (ja) * 2000-01-11 2001-07-19 Omron Corp 車両検出装置および車両管理システム
JP4292955B2 (ja) * 2003-11-12 2009-07-08 日本精工株式会社 スタビリティコントロール装置
US6993449B2 (en) * 2004-01-31 2006-01-31 Continental Teves, Inc. Tire pressure loss detection

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Publication number Priority date Publication date Assignee Title
JPS62149503A (ja) * 1985-12-24 1987-07-03 Nippon Soken Inc 車輪の空気圧検出装置
JP2000255230A (ja) * 1999-02-26 2000-09-19 Continental Ag 空気タイヤの緊急時走行状態を検出する方法と装置
JP2005170065A (ja) * 2003-12-05 2005-06-30 Hitachi Ltd 車両情報メモリエリアを持った無線タグ、車両情報メモリエリアを持った無線タグに読み書きする装置、車両情報メモリエリアを持った無線タグに読み書きする方法、車両情報メモリエリアを持った無線タグに読み書きする装置を備えた車両
JP2005186702A (ja) * 2003-12-24 2005-07-14 Bridgestone Corp タイヤ及びタイヤ摩耗状態推定方法とその装置
JP2006131137A (ja) * 2004-11-08 2006-05-25 Denso Corp 車両用信号処理装置
WO2010147004A1 (fr) * 2009-06-15 2010-12-23 Ntn株式会社 Système de contrôle de la pression d'air de pneumatique

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