JP2007106324A - Wheel information processor and wheel information processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel information processor and wheel information processing method enabling appropriate processing of information relevant to a wheel even when disturbance is applied to the wheel or abnormality occurs in a detecting means set up in the wheel. <P>SOLUTION: The wheel information processor set up in a vehicle 10 comprises a plurality of acceleration sensors 26 that are set up in the wheel 14 and detect acceleration of a tire 18, and an ECU 100. The ECU 100 comprises a wheel force calculation section 101 for calculating a lateral force or load acting on the wheel 14 based on detected values or the like of the acceleration sensors 26, and a determination section 103 for determining whether the calculated value of the wheel force calculation section 101 is calculated based on the acceleration or the like normally detected by the acceleration sensors 26 or the like. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wheel information processing apparatus and a wheel information processing method for processing information related to wheels of a vehicle.

  2. Description of the Related Art Conventionally, a vehicle tire is known in which a strain gauge for detecting a strain of rubber at a corresponding portion is embedded in at least one of a tread portion, a sidewall portion, and a bead portion (see, for example, Patent Document 1). . By using this type of tire, it is possible to grasp the contact state between the tire and the road surface based on the output value of the strain gauge. Conventionally, there is known a device that estimates the running state of a vehicle based on an output level (vibration level) of vibration of the lower part of the vehicle spring detected by a vibration sensor provided in the lower part of the vehicle spring (for example, a patent). Reference 2). In this device, the frequency spectrum of the vibration level is obtained by frequency-converting the vibration level of the lower part of the vehicle spring detected by the vibration sensor, and the vibration levels of at least two frequency bands of the obtained frequency spectrum are calculated, The road surface state is estimated by comparing the level calculation value with the frequency spectrum master curve of the vibration level stored in advance.

Furthermore, conventionally, a tire condition detection device that detects a condition of a tire using a radial strain gauge and a circumferential strain gauge arranged on a sidewall of the tire is known (see, for example, Patent Document 3). . When it is determined from the detected value of the radial strain gauge that the tire has a radial strain, the tire condition detection device detects that the radial strain is based on a temporal change in the output of the radial strain gauge. It is determined whether it is due to a low internal pressure. Further, the tire condition detection device determines whether or not abnormal deformation due to a standing wave, which is likely to occur at a low internal pressure, has occurred in the tire based on a change in the output of the circumferential strain gauge over time.
Further, Patent Document 4 adds to the tire by detecting and comparing the contact length indicators having a 1: 1 correspondence with the contact length of the tire such as the contact time of the tire tread portion at a plurality of positions of the tire. A method for estimating the lateral force that is present is disclosed.
JP 2003-226120 A International Publication No. 01/098123 Pamphlet Japanese Patent Laying-Open No. 2005-041271 JP 2005-205956 A

  As described above, various sensors can be provided on a tire or the like constituting a vehicle wheel, and a road surface state, a wheel state, or the like can be monitored based on a predetermined physical quantity detected by the sensor. In recent years, it has also been proposed to obtain a force acting on a wheel from a physical quantity detected by a sensor provided on the wheel, and to control the behavior of the vehicle while considering the obtained force. However, since various disturbances act on the wheels while the vehicle is running, the sensors provided on the wheels also detect disturbance components due to road surface irregularities in addition to the physical quantities that should be detected. The detection accuracy of the sensor may deteriorate. Moreover, when some abnormality occurs in the sensor provided on the wheel, desired information related to the wheel cannot be obtained satisfactorily from the detection value of the sensor. For this reason, in order to appropriately execute vehicle control using information related to the wheels obtained from the detection values of the sensors, it is necessary to consider disturbances applied to the wheels, sensor abnormalities, and the like.

  Therefore, the present invention provides a wheel information processing apparatus and wheel information that enable appropriate processing of information related to a wheel even when a disturbance is applied to the wheel or an abnormality occurs in a detection unit provided on the wheel. The purpose is to provide a processing method.

  A wheel information processing apparatus according to the present invention is a wheel information processing apparatus for processing information related to a wheel of a vehicle, based on a detection means provided on the wheel for detecting a predetermined physical quantity, and a detection value of the detection means. Wheel force calculation means for calculating the force acting on the wheel, and determination means for determining whether or not the calculated value of the wheel force calculation means is calculated based on the physical quantity normally detected by the detection means. It is characterized by providing.

  The wheel force calculation means of the wheel information processing device calculates the force acting on the wheel based on the detection value of the detection means provided on the vehicle wheel for detecting a predetermined physical quantity. The calculated value of the wheel force calculating means can be used for various vehicle controls such as vehicle behavior control. The calculation value of the wheel force calculation means is subjected to a determination process by the determination means to determine whether or not it is calculated based on the physical quantity normally detected by the detection means. As a result, according to this wheel information processing apparatus, it is possible to determine whether the calculated value of the wheel force calculating means accurately indicates the force actually acting on the wheel, so that a disturbance is applied to the wheel. Even if the physical quantity is not normally detected by the detection means due to deterioration of the detection accuracy of the detection means or an abnormality in the detection means provided on the wheel, the wheel as information related to the wheel It is possible to appropriately process the calculated value of the force calculating means.

  The wheel information processing apparatus according to the present invention calculates the wheel force when the determination unit determines that the calculated value of the wheel force calculation unit is not calculated based on the physical quantity normally detected by the detection unit. It is preferable to further include means for invalidating the calculated value of the means.

  Under this aspect, when it is determined by the determining means that the calculated value of the wheel force calculating means is not calculated based on the physical quantity normally detected by the detecting means, the calculated value of the wheel force calculating means is It will not be used for vehicle control or the like. Therefore, according to this aspect, the wheel force that does not accurately indicate the force actually acting on the wheel when the target physical quantity is not normally detected by the detection means due to disturbance or failure. It is possible to suppress the vehicle control or the like from being performed based on the calculated value of the calculating means.

  Further, the vehicle has a plurality of wheels, and the detection means is provided for each of the plurality of wheels, and the wheel force calculation means calculates the force acting on the wheels for each of the plurality of wheels based on the detection value of the detection means. The determining means may determine whether the calculated value of the wheel force calculating means is calculated based on the physical quantity normally detected by the detecting means for each of the plurality of wheels. If the determination means determines that the calculated value of the wheel force calculation means for any of the wheels is not calculated based on the physical quantity normally detected by the detection means, it is detected normally by the detection means. It is preferable to further include wheel force estimating means for estimating the force acting on any of the wheels based on the calculated value of the wheel force calculating means determined to have been calculated based on the physical quantity.

  Under this aspect, when it is determined by the determining means that the calculated value of the wheel force calculating means for any wheel is not calculated based on the physical quantity normally detected by the detecting means, the wheel With respect to the above, not the calculated value of the wheel force calculating means but the estimated value of the wheel force estimating means is used for vehicle control or the like. Therefore, according to this aspect, even if the target physical quantity is not normally detected by the detection means due to disturbance or failure, the estimated value of the force actually acting on the wheel is used. Thus, the vehicle can be appropriately controlled.

  Further, the determination means is calculated based on a physical quantity that the calculation value of the wheel force calculation means is normally detected by the detection means, based on a balance condition of the force acting on the wheel that is established according to the running state of the vehicle. It is preferable to determine whether it is a thing.

  According to this aspect, it is possible to accurately determine whether or not the calculated value of the wheel force calculating means is calculated based on the physical quantity normally detected by the detecting means.

  Further, the wheel force calculation means calculates a lateral force in the wheel width direction acting on each wheel of the vehicle based on the detection value of the detection means, and the determination means determines between the left and right wheels according to the steering state of the vehicle. Whether or not the calculated value of the wheel force calculation means is based on the physical quantity normally detected by the detection means based on the balance condition of the lateral force or the balance condition of the lateral force between the front and rear wheels Is preferable.

  In general, when the vehicle is steered and the steering angle is small, the lateral forces acting on the left and right front wheels of the vehicle are substantially equal, and the lateral forces acting on the left and right rear wheels are also substantially equal. In addition, when the vehicle turns at a substantially constant steering angle and a substantially constant vehicle speed, the ratio of the lateral forces acting on the right wheel of the vehicle is substantially constant, and the ratio of the lateral forces acting on the left wheel is also approximately. It becomes constant. Therefore, according to the steering state of the vehicle, if it is determined whether or not the lateral force of each wheel calculated by the wheel force calculation means based on the detection value of the detection means satisfies any of these lateral force balance conditions. It is possible to accurately determine whether or not the calculated value of the wheel force calculating means is calculated based on the physical quantity normally detected by the detecting means.

  In this case, a plurality of detection means are provided in the wheel circumferential direction and provided in a plurality of rows in the wheel width direction with respect to the wheel, and an acceleration acquisition means for obtaining acceleration in the predetermined direction of the wheel based on each detection value. Preferably, the wheel force calculating means calculates the lateral force based on the ratio between the contact lengths of the wheels in the vehicle front-rear direction obtained from the detection values of the acceleration acquisition means in each row.

  Thus, when the acceleration acquisition means as the detection means is provided for the wheels in a plurality of rows in the wheel width direction, the ground contact length in the vehicle front-rear direction of the wheels obtained for each row of the acceleration acquisition means is the lateral force acting on the tire. It changes according to the size of. Therefore, according to this aspect, it is possible to accurately obtain the lateral force acting on the wheel in the wheel width direction.

  Further, the wheel force calculation means calculates the load in the wheel height direction acting on each wheel of the vehicle based on the detection value of the detection means, and the determination means calculates the load fluctuation due to steering according to the traveling state of the vehicle. Whether or not the calculated value of the wheel force calculation means is calculated based on the physical quantity normally detected by the detection means based on the load balance condition considered or the load balance condition between the left and right wheels Is preferable.

  In general, when the vehicle is steered, the load acting on the front wheels and the rear wheels due to the steering varies by an amount (a load variation) obtained from a predetermined relational expression from the load during steady running. In addition, when the vehicle is not being steered, the loads acting on the left and right front wheels of the vehicle are approximately equal, and the loads acting on the left and right rear wheels are also approximately equal. Therefore, if it is determined whether the load of each wheel calculated by the wheel force calculation means based on the detection value of the detection means satisfies any of these load balancing conditions according to the running state of the vehicle, the wheel It is possible to accurately determine whether or not the calculated value of the force calculating means is calculated based on the physical quantity normally detected by the detecting means.

  In this case, the detection means may be an acceleration acquisition means that is provided in a plurality in at least the wheel circumferential direction with respect to the wheel and obtains acceleration in a predetermined direction of the wheel based on each detection value. Preferably, the load is calculated based on the ground contact length of the wheel in the vehicle front-rear direction obtained from the detection value of each acceleration acquisition means of the wheel and the air pressure of the tire constituting the wheel.

  According to this aspect, the load in the wheel height direction acting on the wheel can be obtained with high accuracy.

  The wheel information processing apparatus according to the present invention may further include a wheel force estimating unit that estimates a force acting on the wheel separately from the wheel force calculating unit, and the determining unit includes the calculated value of the wheel force calculating unit and the wheel force. It is preferable to determine whether or not the calculated value of the wheel force calculating means is calculated based on the physical quantity normally detected by the detecting means based on the deviation from the estimated value of the estimating means.

  The lateral force acting on the vehicle wheel and the load in the wheel height direction can be calculated with relatively high accuracy based on other parameters without using the detection value of the detection means provided on the wheel, such as the acceleration of the wheel. it can. Therefore, when the wheel information processing apparatus includes a wheel force estimating unit that estimates the force acting on the wheel separately from the wheel force calculating unit, the calculated value of the wheel force calculating unit and the estimated value of the wheel force estimating unit Even if the deviation is used as a determination criterion, it can be determined whether the calculated value of the wheel force calculating means accurately indicates the force actually acting on the wheel. As a result, according to this aspect, it is possible to appropriately process the calculated value of the wheel force calculating means as information related to the wheel when the detection accuracy of the detecting means is deteriorated due to a disturbance on the wheel. It becomes.

  In this case, when the deviation between the calculated value of the wheel force calculating means and the estimated value of the wheel force estimating means is within a predetermined range, the determining means is a physical quantity in which the calculated value of the wheel force calculating means is normally detected by the detecting means. It is preferable to determine that it is calculated based on the above.

  Furthermore, the wheel information processing apparatus according to the present invention may further include a sprung acceleration detecting means for detecting a sprung acceleration of the vehicle, and the determining means calculates a wheel force based on a detection value of the sprung acceleration detecting means. It may be determined whether the calculated value of the means is calculated based on a physical quantity normally detected by the detecting means.

  In general, when a vehicle passes over so-called cleats, potholes, or curbs, the tires that make up the wheels are greatly deformed three-dimensionally, so the target physical quantity is accurately detected by the detection means provided on the wheels. May not be able to be done. In addition, when the vehicle passes over a so-called cleat, pothole, or curb, the sprung acceleration of the vehicle increases and exceeds a certain threshold. Therefore, as in this aspect, even if the detection value of the sprung acceleration detecting means for detecting the sprung acceleration of the vehicle is used as a criterion, the force that the calculated value of the wheel force calculating means is actually acting on the wheel can be obtained. It is possible to determine whether or not the accuracy is indicated. As a result, according to this aspect, it is possible to appropriately process the calculated value of the wheel force calculating means as information related to the wheel when disturbance is applied to the wheel and the detection accuracy of the detecting means is deteriorated. Become.

  In this case, the wheel information processing apparatus according to the present invention may further include unsprung acceleration detecting means for detecting unsprung acceleration of the vehicle, and the determining means may be configured such that the detection value of the unsprung acceleration detecting means exceeds a predetermined threshold value. In addition, when the detection value of the sprung acceleration detection unit exceeds a predetermined threshold value, it is preferable to determine that the calculation value of the wheel force calculation unit is not calculated based on the physical quantity normally detected by the detection unit. .

  The detection means is preferably an acceleration sensor that is disposed on the inner surface of the tread portion of the tire constituting the wheel and detects the acceleration of the tire in the wheel circumferential direction or the wheel radial direction.

That is, if the change in the tire acceleration in the tire circumferential direction or the tire radial direction is grasped, the contact length in the vehicle longitudinal direction of the tire can be accurately obtained from the time interval between the peaks in the acceleration waveform. The lateral force and load acting on the wheel can be accurately calculated from the contact length.
Instead of the acceleration sensor, a strain gauge is disposed on the inner surface of the tread portion of the tire, and the tire amount in the wheel circumferential direction or the wheel radial direction is obtained by differentiating the detected strain amount with an in-vehicle control device. The acceleration may be calculated. In this case, the detection means in the claims comprises a strain gauge and a control device.

A wheel information processing method according to the present invention is a wheel information processing method for processing information related to a vehicle wheel.
(A) detecting a predetermined physical quantity of the wheel using detection means provided on the wheel;
(B) calculating a force acting on the wheel based on a detection value of the detection means;
(C) determining whether or not the calculated value in step (b) is calculated based on the physical quantity normally detected by the detecting means.

  According to the present invention, it is possible to appropriately process information related to a wheel even if a disturbance is applied to the wheel or an abnormality occurs in a detection unit provided on the wheel.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic configuration diagram showing a vehicle including a wheel information processing apparatus according to the first embodiment of the present invention, and FIG. 2 is a partial cross-sectional view showing wheels provided in the vehicle of FIG. A vehicle 10 shown in FIG. 1 includes four wheels 14 provided on a vehicle body 12, a steering device (not shown) that steers steering wheels among these four wheels 14, and among these four wheels 14. A driving drive source (not shown) for driving the driving wheels, a braking device, and the like are provided. Each wheel 14 includes a wheel 16 and a tire 18. In the present embodiment, a so-called run flat tire is adopted as the tire 18 constituting the wheel 14. However, it goes without saying that a general hollow tire other than the run-flat tire may be adopted as the tire 18.

  As shown in FIG. 2, the tire 18 is a so-called side-reinforced run-flat tire that enables run-flat running when the air pressure decreases. As shown in FIG. 2, the tire 18 includes a pair of bead portions 181 in which a bead core 180 is embedded, a pair of sidewall portions 182 extending from the bead portion 181 outward in the tire radial direction, and both sidewall portions 182. An extended tread portion 183. A carcass 184 made of, for example, a single fiber material is embedded in the pair of bead portions 181, the pair of sidewall portions 182 and the tread portion 183, and the tread portion 183 is positioned outside the carcass 184. A belt layer 185 is embedded. Reinforcing rubber 187 is embedded in each sidewall portion 182 so as to be located inside the inner liner 186.

  Each reinforcing rubber 187 has high rigidity, and supports the entire tire 18 with respect to the wheel 16 when the air pressure in the tire internal space 188 defined by the wheel 16 and the tire 18 decreases due to puncture or the like. As a result, run-flat driving is enabled. Further, a driving type or a pasting type balance weight 17 is appropriately attached to the wheel 16. Note that the tire 18 provided in the vehicle 10 is not limited to a side-reinforced run-flat tire, and the entire tire 18 is supported to the wheel 16 when the air pressure in the tire internal space 188 decreases. A core-type run flat tire including a child may be used.

  As shown in FIGS. 1 and 2, each wheel 14 described above is equipped with a TPMS valve 20 that functions as a tire pressure adjusting valve. Each TPMS valve 20 is attached to a mounting hole 16b provided in the wheel rim 16a of the wheel 16 via a grommet 19 made of elastic rubber, a washer, and a bolt. The grommet 19 has a predetermined rigidity and keeps the tire internal space 188 airtight. Further, the valve cap 20a of the TPMS valve 20 protrudes to the outside of the wheel rim 16a. If the valve cap 20a is removed and a hose of an air supply device is connected to a valve port (not shown), the tire inner space 188 is formed. Air can be supplied. As shown in FIG. 2, each TPMS valve 20 has a housing 21 protruding into the tire internal space 188, and the air pressure in the tire internal space 188 is stored in the housing 21 as wheel information. An air pressure sensor 22a to detect is disposed.

Each wheel 14 described above is provided with a plurality of acceleration sensors 26. As shown in FIG. 2, each acceleration sensor 26 is fixed to the inner surface of the tread portion 183 of the tire 18, and detects acceleration in the tire circumferential direction of the tire 18 as wheel information (physical quantity) at each installation location. As shown in FIG. 3, a plurality of acceleration sensors 26 are provided in the tire circumferential direction and in a plurality of rows in the tire width direction with respect to the inner surface of the tread portion 183. In the present embodiment, a total of 20 acceleration sensors 26 are arranged on the inner surface of the tread portion 183 at intervals of 18 ° in the tire circumferential direction.
In addition, a strain gauge is provided on the wheel instead of the acceleration sensor, and the acceleration is calculated by differentiating the strain amount as an output value in an electronic control unit (hereinafter referred to as “ECU”) mounted on the vehicle body 12. May be.

  In this embodiment, two rows of acceleration sensors 26 are provided at intervals W, and each acceleration sensor 26 in the tire outer row and each acceleration sensor 26 in the tire inner row are the width of the tire 18. It arrange | positions so that it may adjoin in a direction. Each acceleration sensor 26 may detect acceleration in the tire radial direction of the tire 18 as wheel information at the installation location. Further, three or more rows of acceleration sensors 26 may be provided for the tire 18 of each wheel 14.

  FIG. 4 is a control block diagram of the wheel information processing apparatus according to the present invention. As shown in the figure, in the housing 21 of the TPMS valve 20, an acceleration sensor 22g, a TPMS communication device 23, a control circuit 24, and a battery 25 are accommodated in addition to the air pressure sensor 22a. Thereby, each TPMS valve | bulb 20 functions also as a means which can transmit the wheel information acquired regularly while acquiring the tire pressure and wheel acceleration (wheel vibration) as wheel information, respectively. The air pressure sensor 22a is a semiconductor sensor, for example, and detects the air pressure in the tire internal space. The acceleration sensor 22g functions as means for detecting unsprung acceleration of the vehicle 10 and detects acceleration in the width direction and / or radial direction (vertical direction) of the corresponding traveling wheel 14 as unsprung vibration of the vehicle 10. The acceleration sensor 22g may be omitted from the TPMS valve 20, or may be provided on a knuckle or the like that supports the wheel 14.

  The TPMS communication device 23 is capable of periodically wirelessly transmitting a signal indicating a detection value of the air pressure sensor 22a or a detection value of the acceleration sensor 22g at a predetermined period. The control circuit 24 is mounted on an IC chip or the like, and controls the air pressure sensor 22a, the acceleration sensor 22g, and the TPMS communication device 23. The battery 25 supplies power to the air pressure sensor 22a, the acceleration sensor 22g, the TPMS communication device 23, and the control circuit 24. The TPMS valve 20 may further include a temperature sensor that detects the temperature in the tire internal space.

  Each acceleration sensor 26 provided on the tire 18 is connected to a communication device (transmitter) 28 via an amplifier 27, and each wheel 14 is connected to the acceleration sensor 26, the amplifier 27, and the communication device. A battery 29 for supplying electric power to 28 is provided. In the present embodiment, one communication device 28 is assigned to five acceleration sensors 26 (and amplifiers 27). The amplifier 27, the communication device 28, and the battery 29 are disposed at appropriate positions of the corresponding wheel 14, for example, the outer peripheral surface of the wheel 16. The amplifier 27 amplifies the output of the corresponding acceleration sensor 26 and gives it to the communication device 28. The communication device 28 outputs a signal indicating the output value of the corresponding five acceleration sensors 26 at a cycle of, for example, about 1 to 20 msec. Information can be transmitted wirelessly.

  Further, as shown in FIGS. 1 and 4, a plurality of (four in the present embodiment) vehicle body side communication devices 30 are arranged on the vehicle body 12 of the vehicle 10 so as to correspond to the respective wheels 14. . Each vehicle body side communication device 30 can transmit and receive signals indicating wheel information and the like to and from the TPMS communication device 23 and the communication device 28 provided on the corresponding wheel 14. The vehicle body 12 may be provided with a single vehicle body side communication device capable of transmitting and receiving signals indicating wheel information and the like between the TPMS communication device 23 and the communication device 28 provided on each wheel 14. . Each vehicle body side communication device 30 is connected to an ECU 100 mounted on the vehicle body 12 as shown in FIGS. 1 and 4. Each vehicle body side communication device 30 receives a signal wirelessly transmitted from the TPMS communication device 23 or the communication device 28 of the corresponding wheel 14 and gives the received information to the ECU 100. Wheel information from the TPMS communication device 23 and the communication device 28 is stored and held by a predetermined amount in a predetermined storage area (buffer) of the ECU 100, and the ECU 100 performs various controls using information received from each vehicle body side communication device 30. Execute.

  The ECU 100 includes a CPU that executes various arithmetic processes, a ROM that stores various control programs, a RAM that is used as a work area for data storage and program execution, an input / output interface, a memory, and the like. As shown in FIG. 1, an alarm device 105 is connected to the ECU 100. The warning device 105 issues a warning to the driver under predetermined conditions under the control of the ECU 100, and includes, for example, a warning display device provided on the instrument panel of the vehicle 10.

  In addition, a plurality of sensors are connected to the ECU 100 as shown in FIG. Sensors connected to the ECU 100 include a steering angle sensor 110, a wheel speed sensor 111, a longitudinal G sensor 112, a lateral G sensor 113, a yaw rate sensor 114, a sprung G sensor 115, and the like. The steering angle sensor 110 detects a steering angle of a steering wheel (not shown) and gives a signal indicating the detected value to the ECU 100. The wheel speed sensor 111 is provided for each wheel 14 to detect the speed of the corresponding wheel 14 and gives a signal indicating the detected value to the ECU 100. The front-rear G sensor 112 detects acceleration (front-rear acceleration) in the front-rear direction of the vehicle 10 and gives a signal indicating the detected value to the ECU 100.

  The lateral G sensor 113 detects the acceleration (lateral acceleration) in the lateral direction of the vehicle 10, that is, the vehicle width direction, and gives a signal indicating the detected value to the ECU 100. The yaw rate sensor 114 detects the rotational angular velocity (yaw rate) around the vertical axis of the vehicle 10 and gives a signal indicating the detected value to the ECU 100. The sprung G sensor 115 is attached to a structural member of the vehicle body 12 or the suspension, for example. The sprung G sensor 115 detects the acceleration in the width direction and / or the vertical direction of the vehicle 10 (the vehicle body 12) at the corresponding location as the sprung vibration of the vehicle 10, and gives a signal indicating the detected value to the ECU 100.

  In the vehicle 10 configured as described above, an ECBECU 200 (see FIG. 1) that controls a braking device (electronically controlled braking device) cooperates with an ECU that controls a traveling drive source, an ECU that controls a steering device, and the like. In order to stabilize the behavior of the vehicle 10, integrated control (VDIM: Vehicle Dynamics Integrated Management) of driving, steering and braking of the vehicle 10 is executed. In such integrated control, from the viewpoint of executing vehicle motion control with high accuracy, the lateral force in the wheel width direction acting on the tire 18 of each wheel 14 and the load (vertical force) in the wheel height direction are accurately determined. It is required to get. For this reason, in the vehicle 10 of this embodiment, the above-described ECU 100 calculates the lateral force and the load acting on the tire 18 of each wheel 14 based on the wheel information from each wheel 14.

  For this reason, as shown in FIG. 4, the above-described ECU 100 mainly receives a lateral force or a load acting on each wheel 14 based on a detection value of each acceleration sensor 26 or the like sent from the communication device 28 or the like of each wheel 14. Is constructed. Further, in the ECU 100, a wheel force estimation unit 102 is constructed separately from the wheel force calculation unit 101. The wheel force estimation unit 102 of the present embodiment estimates a lateral force acting on other wheels 14 based on the force acting on at least two wheels 14 calculated by the wheel force calculation unit 101, or has a predetermined relationship. The load acting on the wheel 14 is estimated using an equation. The ECU 100 also has a determination unit 103 and a storage device 104. The determination unit 103 determines whether or not the calculated value of the wheel force calculation unit 101 is calculated based on the acceleration or the like normally detected by each acceleration sensor 26 or the like of the wheel 14. In the storage device 104, various coefficients used for calculation of wheel force by the wheel force calculation unit 101, the above-described functional expressions used for wheel force estimation by the wheel force estimation unit 102, and various types used for determination processing by the determination unit 103. A threshold value and the like are stored.

  FIG. 5 is a flowchart for explaining the calculation procedure of the lateral force acting on the wheel 14 by the wheel force calculation unit 101. The routine shown in the figure is executed for each wheel 14 every predetermined time by the wheel force calculation unit 101 of the ECU 100 while the vehicle 10 is traveling. When it is time to execute the routine of FIG. 5 for a certain wheel 14, the wheel force calculation unit 101 is based on acceleration information from each acceleration sensor 26 of the wheel 14 (tire 18) stored in a predetermined storage area. The time interval Δt between peaks in the acceleration waveform obtained from the detection value of each acceleration sensor 26 is obtained (S10).

  Here, each acceleration sensor 26 detects acceleration in the tire circumferential direction of the tire 18 at the installation location as described above. Therefore, as shown in FIG. 6, a signal indicating a large acceleration value (peak value) is output from the acceleration sensor 26 located near the front end of the ground contact portion of the tire 18 that rotates while the vehicle 10 is traveling. Similarly, a signal indicating a large acceleration value (peak value) is output from the acceleration sensor 26 located near the rear end of the ground contact portion of the tire 18 that rotates while the vehicle 10 is traveling, as shown in FIG. For this reason, in S10, the wheel force calculation unit 101 calculates the time interval Δt between the peaks in the acceleration waveform based on the sampling time of the acceleration sensor 26, the data sampling number between the peaks of the acceleration waveform, and the like.

  When the time interval Δt is calculated, the wheel force calculation unit 101 calculates the time interval Δt, the wheel speed indicated by the signal from the wheel speed sensor 111 corresponding to the corresponding wheel 14, the tire radius that is known in advance, and the like. Based on this, the contact length CL in the vehicle longitudinal direction of the tire 18 of the corresponding wheel 14 is calculated (S12). In the present embodiment, since the acceleration sensors 26 are provided in two rows for the tires 18 of the wheels 14 as described above, in S12, based on signals from the acceleration sensors 26 in the inner rows of the tires 18. A contact length CLi obtained from the calculated time interval Δt and a contact length CLo obtained from the time interval Δt calculated based on a signal from the acceleration sensor 26 in the outer row of the tire 18 are calculated.

  When the ground contact lengths CLi and CLo of the tire 18 in the longitudinal direction of the vehicle are calculated, the wheel force calculation unit 101 calculates the contact length CLi obtained from the time interval Δt calculated based on the signal from the acceleration sensor 26 in the inner row of the tire 18. The lateral force F in the wheel width direction acting on the wheel 14 is obtained from the ratio of the contact length CLo obtained from the time interval Δt calculated based on the signal from the acceleration sensor 26 in the outer row of the tire 18 ( S14). That is, when the acceleration sensor 26 is provided in a plurality of rows (two rows) in the tire width direction with respect to the tire 18 as described above, the ground contact lengths CLi and CLo in the vehicle longitudinal direction of the tire 18 obtained for each row of the acceleration sensor 26 are obtained. Changes according to the magnitude of the lateral force F acting on the wheel 14. Therefore, if the ratio between the contact lengths CLi and CLo is used, the lateral force F acting on the wheel 14 in the wheel width direction can be accurately obtained. In the present embodiment, a map or a function formula that defines the correlation between the ratio of the contact length CLi inside the tire and the contact length CLo outside the tire and the lateral force F is predetermined and stored in the storage device 104. The wheel force calculation unit 101 acquires the lateral force F using the map or the function formula. Such a map or function formula is basically created with reference to the time of steering during steady running (constant speed running) of the vehicle 10.

  As described above, the plurality of acceleration sensors 26 are disposed on the inner surface of the tread portion 183 of the tire 18, and by detecting the acceleration of the tire 18 in the tire circumferential direction or the tire radial direction, the tire circumferential direction or the tire radial direction is detected. The change in acceleration of the tire 18 can be grasped, and the contact length CL in the vehicle longitudinal direction of the tire 18 can be accurately obtained from the time interval Δt between peaks in the acceleration waveform.

  Here, the vehicle 10 is accelerated or decelerated during its travel. However, when the vehicle 10 is accelerated or decelerated, load movement in the front-rear direction of the vehicle 10 occurs. The contact lengths CLi and CLo of the tire 18 in the vehicle front-rear direction may change. Therefore, even if the lateral force F acting on the tire 18 can be accurately obtained based on the ground contact lengths CLi, CLo during steering during steady running of the vehicle 10, the load movement in the front-rear direction is performed when the vehicle 10 is accelerated or decelerated. Therefore, there is a possibility that the lateral force acquisition accuracy is deteriorated.

  For this reason, the wheel force calculation part 101 will acquire the acceleration in the front-back direction of the vehicle 10 via the front-back G sensor 112, if the process of S14 is performed (S16). And the wheel force calculation part 101 acquires correction amount (DELTA) F of lateral force F according to the acceleration in the front-back direction of the acquired vehicle 10, and uses lateral force F acquired in S14 using acquired correction amount (DELTA) G, Correction is performed as F = F + ΔF (S18). In the present embodiment, a map or function formula that defines the correlation between the acceleration in the longitudinal direction of the vehicle 10 and the correction amount ΔF is determined in advance and stored in the storage device 104 through experiments and analysis, and the wheel force calculation unit 101 acquires the correction amount ΔF using the map or the function formula.

  Thus, by correcting the lateral force F obtained from the contact lengths CLi and CLo based on the acceleration in the front-rear direction of the vehicle 10, the vehicle 10 in the front-rear direction even when the vehicle 10 is accelerating or decelerating. The lateral force in the tire width direction that acts on the tire 18 while suppressing the influence of the load movement can be obtained with high accuracy. The lateral force calculated in this way is used for the vehicle integrated control described above. However, it goes without saying that the lateral force F can be used for, for example, general ABS control and vehicle stabilization control (VSC).

  By the way, since various disturbances act on each wheel 14 while the vehicle 10 is traveling, each acceleration sensor 26 provided on the tire 18 of the wheel 14 has a relatively large road surface unevenness in addition to the acceleration to be detected. As a result, the detection of the acceleration sensor 26 and the like may be deteriorated. In addition, when some abnormality occurs in the acceleration sensor 26 provided on the tire 18 of the wheel 14, desired information such as a lateral force acting on the wheel 14 cannot be satisfactorily obtained from the detection value of the acceleration sensor 26. Therefore, in order to appropriately execute vehicle control using information related to the wheels 14 obtained from the detection values of the sensors 22a and 22g of the acceleration sensor 26 and the TPMS valve 20, disturbances applied to the wheels 14, sensor abnormalities, etc. Need to be considered.

Here, regarding the lateral force acting on the tire 18 of each wheel 14 of the vehicle 10, the lateral force acting on the right front wheel of the vehicle 10 is Ffr, the lateral force acting on the left front wheel is Ffl, and acts on the right rear wheel. If the lateral force to be applied is Frr and the lateral force acting on the left rear wheel is Frl, the following relationship is established between them. That is, during small steering of the vehicle 10 where the yaw angular velocity ψ is smaller than a predetermined value,
Ffl = Ffr (1)
Frr = Frl (2)
The relationship is established. Also, during steady turning, the yaw angular acceleration ψ ′ is substantially zero,
l ₁ · Ffr = l ₂ · Frr (3)
l ₁ · Ffl = l ₂ · Frl (4)
The relationship is established. Here, l _{1 is} the distance in the front-rear direction from the center of gravity of the vehicle to the ground point of the front wheel, and l ₂ is the distance of the distance in the front-rear direction from the center of gravity of the vehicle to the ground point of the rear wheel.

  That is, when the vehicle 10 is being steered and the steering angle is small, the lateral forces Ffr and Ffl acting on the left and right front wheels of the vehicle 10 are substantially equal, and the lateral forces Frr and Frl acting on the left and right rear wheels are also equal. It becomes almost equal. Further, when the vehicle 10 turns at a substantially constant steering angle and a substantially constant vehicle speed, the ratio between the lateral forces Ffr and Ffl acting on the right wheel of the vehicle 10 is substantially constant, and the lateral force acting on the left wheel. The ratio between Ffr and Ffl is also substantially constant.

  Accordingly, the lateral force acting on each wheel 14 calculated based on the detected value of the acceleration sensor 26 and the like by the wheel force calculation unit 101 during the small steering of the vehicle 10 satisfies the relationship of the above expressions (1) and (2). If substantially satisfied, the acceleration sensor 26 of each wheel 14 has detected the acceleration normally, and the wheel force calculation unit 101 has a lateral force actually acting on the wheel 14 based on the detection value of the acceleration sensor 26 and the like. It can be determined that is calculated with high accuracy. Similarly, the lateral force acting on each wheel 14 calculated based on the detected value of the acceleration sensor 26 and the like by the wheel force calculation unit 101 during steady turning of the vehicle 10 is the relationship of the above expressions (3) and (4). , The acceleration sensor 26 of each wheel 14 has normally detected acceleration, and the wheel force calculation unit 101 is actually acting on the wheel 14 based on the detection value of the acceleration sensor 26 and the like. It can be determined that the force is accurately calculated.

  On the other hand, the lateral force acting on each wheel 14 calculated by the wheel force calculation unit 101 based on the detection value of the acceleration sensor 26 and the like when the vehicle 10 is slightly steered is expressed by the above formulas (1) and (2). If either one of the relations is not satisfied, the acceleration sensor 26 of one of the wheels 14 has not detected the acceleration normally, and the wheel force calculation unit 101 has accurately calculated the lateral force for the wheel 14. There is a risk of not. Similarly, the lateral force acting on each wheel 14 calculated based on the detection value of the acceleration sensor 26 and the like by the wheel force calculation unit 101 during steady turning of the vehicle 10 is any of the above formulas (3) and (4). Even if either of these is not satisfied, the acceleration sensor 26 of any one of the wheels 14 may not normally detect the acceleration, and the wheel force calculation unit 101 may not calculate the lateral force with high accuracy for the wheel 14. is there.

  In view of these points, in the present embodiment, the above-described equations (1) and (2) or (3) and (4) established by the determination unit 103 of the ECU 100 in accordance with the traveling state (steering state) of the vehicle 10. It is determined whether or not the calculated value of the wheel force calculation unit 101 is calculated based on the acceleration or the like normally detected by the acceleration sensor 26 based on the balance condition of the force acting on the wheel 14. .

Further, regarding the lateral force acting on the tire 18 of each wheel 14, the equation of motion shown in the following equations (5) and (6) is established.
M · V (ψ + β) = Ffr + Ffl + Frr + Frl (5)
Iz · ψ ′ = l ₁ · (Ffr + Ffl) −l ₂ · (Frr + Frl) (6)
However, in the above formulas (5) and (6), M: vehicle mass, Iz: yaw moment of inertia, V: vehicle speed, ψ: yaw angular velocity, ψ ': yaw angular acceleration, β: vehicle body slip angle (vehicle longitudinal direction) And the direction of travel of the vehicle).

In these formulas (5) and (6), the vehicle speed V can be actually measured by the wheel speed sensor 111, and the yaw angular velocity ψ, yaw angular acceleration ψ ', and vehicle body skid angle β are obtained from the detected values of the yaw rate sensor 114. Can do. Further, the distances l ₁ and l ₂ are known values inherent to the vehicle 10, and the vehicle mass M and the yaw inertia moment Iz in a state in which the occupant gets on the vehicle 10 also, for example, start running of the vehicle 10 through a predetermined procedure. Sometimes it can be sought. Therefore, if at least two of the lateral forces Ffr, Ffl, Frr, Frl of each wheel are known, the remaining lateral force that is not known can be estimated from the above equations (5) and (6). it can. In the present embodiment, the above-described wheel force estimation unit 102 executes a process for estimating the lateral force acting on the wheel 14 using the equations (5) and (6).

  FIG. 7 shows the procedure of the determination process regarding the lateral force executed by the determination unit 103 of the ECU 100, that is, the acceleration or the like in which the calculated value of the lateral force by the wheel force calculation unit 101 is normally detected by the acceleration sensor 26 of the wheel 14. It is a flowchart for demonstrating the procedure which determines whether it is calculated based on. The routine shown in the figure is repeatedly executed by the determination unit 103 every predetermined time. When the execution timing of the routine of FIG. 7 is reached, the determination unit 103 acquires the yaw angular velocity ψ via the yaw rate sensor 114, and whether or not the absolute value of the yaw angular velocity ψ is below a predetermined threshold ε, that is, the vehicle It is determined whether 10 is in a small steering state (S20). When determining unit 103 determines that yaw angular velocity ψ is lower than threshold value ε (Yes in S20), lateral force Ffr, Ffl, Frr and Frl of each wheel 14 calculated at that time from wheel force calculating unit 101 is determined. Is acquired (S22). Further, the determination unit 103 determines whether or not both of the above expressions (1) and (2) are generally satisfied with respect to the lateral forces Ffr, Ffl, Frr, and Frl acquired in S22 (S24).

  Regarding the lateral forces Ffr, Ffl, Frr and Frl acquired in S22, when it is determined that both of the above formulas (1) and (2) are generally satisfied (Yes in S24), The acceleration sensor 26 of the wheel 14 detects the acceleration normally, and the wheel force calculation unit 101 detects the lateral forces Ffr, Ffl, Frr actually acting on each wheel 14 based on the detection value of the acceleration sensor 26 and the like. Frl is calculated with high accuracy. Therefore, when an affirmative determination is made in S24, the determination unit 103 turns on a predetermined flag indicating that the lateral forces Ffr, Ffl, Frr, and Frl calculated by the wheel force calculation unit 101 are valid ( S26). As a result, the lateral forces Ffr, Ffl, Frr, and Frl calculated by the wheel force calculation unit 101 of the ECU 100 are used when the vehicle integration control or the like by the ECBECU 200 is performed.

  On the other hand, regarding the lateral forces Ffr, Ffl, Frr and Frl acquired in S22, when it is determined that either one of the above formulas (1) and (2) is not satisfied (No in S24), As described above, the acceleration sensor 26 of any one of the wheels 14 does not normally detect acceleration, and the wheel force calculation unit 101 does not accurately calculate the lateral force for the wheel 14. Therefore, when a negative determination is made in S24, the determination unit 103 is a predetermined flag indicating that the lateral forces Ffr ′, Ffl ′, Frr ′ and Frl ′ estimated by the wheel force estimation unit 102 are valid. Is turned on (S28).

  Thereby, when a negative determination is made in S24, that is, the calculated value of the lateral force by the wheel force calculation unit 101 for any one of the wheels 14 by the determination unit 103 is converted into the acceleration or the like normally detected by the acceleration sensor 26. If it is determined that the calculated value is not based on the lateral force Ffr ′, Ffl ′, Frr ′, and Frl ′ estimated by the wheel force estimation unit 102 of the ECU 100 when the vehicle is controlled by the ECBECU 200, etc. Will be.

  It should be noted that the wheel force estimation unit 102 calculates the value of the wheel force calculation unit 101 for the wheel 14 corresponding to the formula determined to be substantially established by the determination unit 103 among the above formulas (1) and (2). Is substituted into the above formulas (5) and (6) to calculate the lateral force for the wheel 14 corresponding to the formula that is not established among the above formulas (1) and (2). Then, the calculated value of the wheel force calculation unit 101 for the wheel 14 corresponding to the expression determined to be substantially established by the determination unit 103 and the calculated value of the lateral force for the remaining remaining wheel 14 are calculated as the lateral force. Are estimated as Ffr ′, Ffl ′, Frr ′ and Frl ′.

  On the other hand, when the determination unit 103 determines that the yaw angular velocity ψ is not lower than the threshold ε (No in S20), the determination unit 103 acquires the yaw angular acceleration ψ ′ via the yaw rate sensor 114, and the absolute value of the yaw angular acceleration ψ ′. Is below a predetermined threshold value ε ′, that is, whether or not the vehicle 10 is in a steady steering state (S30). If the determination unit 103 determines that the yaw angular acceleration ψ ′ is less than the threshold value ε ′ (Yes in S30), the lateral force Ffr, Ffl, Ffl of each wheel 14 calculated from the wheel force calculation unit 101 at that time is determined. Frr and Frl are acquired (S32). Further, the determination unit 103 determines whether or not both of the above formulas (3) and (4) are generally satisfied with respect to the lateral forces Ffr, Ffl, Frr and Frl acquired in S32 (S34).

  Regarding the lateral forces Ffr, Ffl, Frr and Frl acquired in S32, when it is determined that both of the above formulas (3) and (4) are generally satisfied (Yes in S34), The acceleration sensor 26 of the wheel 14 detects the acceleration normally, and the wheel force calculation unit 101 detects the lateral forces Ffr, Ffl, Frr actually acting on each wheel 14 based on the detection value of the acceleration sensor 26 and the like. Frl is calculated with high accuracy. Therefore, when an affirmative determination is made in S34, the determination unit 103 turns on a predetermined flag indicating that the lateral forces Ffr, Ffl, Frr, and Frl calculated by the wheel force calculation unit 101 are valid ( S26). As a result, the lateral forces Ffr, Ffl, Frr, and Frl calculated by the wheel force calculation unit 101 of the ECU 100 are used when the vehicle integration control or the like by the ECBECU 200 is performed.

  On the other hand, regarding the lateral forces Ffr, Ffl, Frr and Frl acquired in S32, when it is determined that either one of the above formulas (3) and (4) is not satisfied (No in S34), As described above, the acceleration sensor 26 of any one of the wheels 14 does not normally detect acceleration, and the wheel force calculation unit 101 does not accurately calculate the lateral force for the wheel 14. For this reason, even when a negative determination is made in S34, the determination unit 103 has a predetermined value indicating that the lateral forces Ffr ′, Ffl ′, Frr ′ and Frl ′ estimated by the wheel force estimation unit 102 are valid. The flag is turned on (S28).

  As a result, even when a negative determination is made in S34, the lateral forces Ffr ′, Ffl ′, Frr ′ and Frl ′ estimated by the wheel force estimating unit 102 of the ECU 100 are used when the vehicle integration control or the like by the ECBECU 200 is performed. It will be. In this case, the wheel force estimation unit 102 is a wheel force calculation unit 101 for the wheel 14 corresponding to the equation determined to be substantially established by the determination unit 103 among the equations (3) and (4). By substituting the calculated value into the above formulas (5) and (6), the lateral force for the wheel 14 corresponding to the formula that is not established among the above formulas (3) and (4) is calculated.

  As described above, in the vehicle 10 according to the present embodiment, for the calculated value of the lateral force of each wheel 14 by the wheel force calculation unit 101, the acceleration obtained by the determination unit 103 in which each calculated value is normally detected by the acceleration sensor 26. A process for determining whether or not the calculated value is based on the above is performed. This makes it possible to determine whether the lateral force calculated by the wheel force calculation unit 101 accurately indicates the lateral force actually acting on the wheel 14, so that disturbance is applied to the wheel 14 and acceleration is performed. As information related to the wheels 14, even if the acceleration is not normally detected by the acceleration sensor 26 due to deterioration of the detection accuracy of the sensor 26 or the like or an abnormality in the acceleration sensor 26 or the like of the wheel 14 The calculated value of the lateral force by the wheel force calculation unit 101 can be appropriately processed.

  That is, in the vehicle 10, when the acceleration is not normally detected by the acceleration sensor 26 provided on the wheel 14 due to disturbance or failure, the lateral force estimated by the wheel force estimating unit 102 in S28 is effective. Is turned on, and the calculated value of the lateral force by the wheel force calculating unit 101 is invalidated. Thereby, it is possible to suppress the vehicle control from being performed based on the calculated value of the wheel force calculation unit 101 that does not accurately indicate the lateral force actually acting on the wheel 14. In such a case, not the calculated value of the wheel force calculating unit 101 but the estimated value of the lateral force by the wheel force estimating unit 102 is used for vehicle control (S28). Therefore, in the present embodiment, even if acceleration is not normally detected by the acceleration sensor 26 due to disturbance or failure, the estimated value of the lateral force actually acting on the wheel 14 is used. The vehicle 10 can be appropriately controlled.

  Further, as described above, according to the steering state of the vehicle 10, the determination process is executed based on the balance condition of the lateral force between the left and right wheels or the balance condition of the lateral force between the front and rear wheels (S24). Alternatively, it is possible to accurately determine whether or not the lateral force calculated value by the wheel force calculating unit 101 is calculated based on the acceleration or the like normally detected by the acceleration sensor 26.

  In addition, when estimating the lateral force in the wheel force estimation unit 102, it is necessary to obtain the vehicle mass M and the yaw inertia moment Iz in a state where the occupant is in the vehicle, but the above (1) to (6) If the relationship is used, the vehicle mass M and the yaw moment of inertia Iz can be obtained according to the procedure shown in FIG. The routine of FIG. 8 is preferably executed by the ECU 100 immediately after the vehicle 10 starts to travel, for example. In this case, when the execution timing of the routine of FIG. 8 is reached, the ECU 100 acquires the yaw angular velocity ψ, and whether or not the absolute value of the yaw angular velocity ψ is below a predetermined threshold ε, that is, the vehicle 10 is in the small steering state. (S120). When the yaw angular velocity ψ is lower than the threshold ε (Yes in S120), the wheel force calculation unit 101 acquires the lateral forces Ffr, Ffl, Frr, and Frl of each wheel 14 calculated at that time (S122). With respect to the acquired lateral forces Ffr, Ffl, Frr and Frl, it is determined whether or not both of the above expressions (1) and (2) are generally satisfied (S124).

  When it is determined in S124 that both of the above expressions (1) and (2) are generally satisfied (Yes in S124), the acceleration sensor 26 of each wheel 14 detects the acceleration normally as described above. Therefore, the wheel force calculation unit 101 accurately calculates the lateral forces Ffr, Ffl, Frr and Frl actually acting on each wheel 14 based on the detection value of the acceleration sensor 26 and the like. For this reason, when an affirmative determination is made in S124, based on the above equations (1) and (2), Ffr = Ffl and Frr = Frl, and using the detection value of the yaw rate sensor 114, the above (5) From the equations (6) and (6), the vehicle mass M and the yaw inertia moment Iz in a state in which the occupant is in the vehicle can be accurately obtained (S126).

  When it is determined that the yaw angular velocity ψ is not lower than the threshold ε (No in S120), the ECU 100 acquires the yaw angular acceleration ψ ′ and the absolute value of the yaw angular acceleration ψ ′ is a predetermined threshold ε ′. Whether or not the vehicle 10 is in a steady steering state is determined (S128). When the yaw angular acceleration ψ ′ is lower than the threshold ε ′ (Yes in S128), the wheel force calculation unit 101 acquires the lateral forces Ffr, Ffl, Frr, and Frl of each wheel 14 calculated at that time ( (S130) With respect to the acquired lateral forces Ffr, Ffl, Frr and Frl, it is determined whether or not both of the above formulas (3) and (4) are generally satisfied (S132).

If it is determined in S132 that both the above expressions (3) and (4) are generally satisfied (Yes in S32), the acceleration sensor 26 of each wheel 14 detects the acceleration normally as described above. Therefore, the wheel force calculation unit 101 accurately calculates the lateral forces Ffr, Ffl, Frr and Frl actually acting on each wheel 14 based on the detection value of the acceleration sensor 26 and the like. For this reason, when an affirmative determination is made in S132, the yaw rate sensor is obtained by setting Ffr = l ₂ / l ₁ · Frr and Ffl = l ₂ / l ₁ · Frl from the above equations (3) and (4). Using the detected value of 114, the vehicle mass M and the yaw inertia moment Iz in a state in which the occupant is in the vehicle can be accurately obtained from the above equations (5) and (6).

  If it is determined in S124 that either one of the above expressions (1) and (2) is not satisfied (No in S124), one of the above expressions (3) and (4) is determined in S132. Is determined to be not satisfied (No in S132), and if it is determined in S128 that the absolute value of the yaw angular acceleration ψ ′ is not less than the threshold value ε ′ (No in S128), the steps after S120 The process is executed repeatedly.

  Next, the process of the load in the wheel height direction which acts on each wheel 14 in the above-described ECU 100 will be described.

  As described above, the ECU 100 is provided with the wheel force calculation unit 101, and the wheel force calculation unit 101 has a wheel height that acts on each wheel 14 in addition to the lateral force F that acts on each wheel 14. A load L in the vertical direction is also calculated. That is, the wheel force calculation unit 101 calculates the load L based on the ground contact length CL of the tire 18 in the vehicle longitudinal direction and the tire air pressure detected by the air pressure sensor 22a of the TPMS valve 20. In the present embodiment, a map or a function formula that defines the correlation between the contact length CL of the tire 18 in the vehicle longitudinal direction and the tire air pressure, and the load L is determined in advance and stored in the storage device 104, and the wheel force calculation unit 101 acquires the load L using the said map or function type | formula.

In this embodiment, since the acceleration sensors 26 are provided in two rows for the tires 18 of the wheels 14 as described above, the contact length CL of each tire 18 is a signal from the acceleration sensor 26 of each row. Is calculated as an average value of the contact lengths CLi and CLo obtained from the time interval Δt calculated based on That is, if the contact length obtained based on the signal from the acceleration sensor 26 in the inner row of the tire 18 is CLi, and the contact length obtained based on the signal from the acceleration sensor 26 in the outer row of the tire 18 is CLo, the tire The contact length CL of 18 is
CL = (CLi + CLo) / 2
Is calculated as Thereby, it becomes possible to obtain | require the load L in the wheel height direction which acts on each wheel 14 accurately.

Here, regarding the load acting on the tire 18 of each wheel 14, the load Lfr acting on the right front wheel of the vehicle 10, the load acting on the left front wheel is Lfl, the load acting on the right rear wheel is Lrr, and the left If the load acting on the rear wheel is Lrl, the equation of motion shown in the following equation (7) is established.
M · g = Lfr + Lfl + Lrr + Lrl (7)
Therefore, for example, if the loads Lfr ₀ , Lfl ₀ , Lrr ₀ and Lrr ₀ acting on each wheel 14 calculated by the wheel force calculation unit 101 during steady traveling in which the vehicle 10 goes straight at a substantially constant speed are used, Thus, the vehicle mass M can be obtained with high accuracy.

  Further, if the load fluctuation amount during steady running of each front wheel when the vehicle 10 is in a steering state is ΔLf, and the load fluctuation amount during steady running of each rear wheel when the vehicle 10 is in a steering state is ΔLr, The load fluctuations ΔLf and ΔLr can be obtained from the following equations (8) and (9).

However, in the equations (8) and (9), df: front red, dr: rear tread, l: wheel base, Kf: front roll rigidity (moment required for the vehicle to rotate 1 ° around the front rotation center) , Kr: rear roll rigidity (moment required for the vehicle to rotate 1 ° around the rotation center of the rear), hs: distance from the center of gravity to the roll axis (axis connecting the front rotation center and the rear rotation center), a _y : lateral acceleration of the vehicle 10

The loads Lfr ₀ , Lfl ₀ , Lrr ₀ and Lrl ₀ acting on each wheel 14 calculated by the wheel force calculation unit 101 during steady running, and the front and rear wheels obtained from the above equations (8) and (9) When the vehicle 10 is steered, the following equations (10) to (13) are established.
Lfr = Lfr ₀ + ΔLf (10)
Lfl = Lfl ₀ −ΔLf (11)
Lrr = Lrr ₀ + ΔLr (12)
Lrl = Lrl ₀ −ΔLr (13)
However, when traveling straight ahead, Lfr ₀ = Lfl ₀ and Lrr ₀ = Lrl ₀ can be considered.

  Therefore, when the vehicle 10 is steered, the load acting on each wheel 14 calculated based on the detection values of the acceleration sensor 26 and the air pressure sensor 22a of the TPMS valve 20 by the wheel force calculation unit 101 is the above (10) to ( 13) If the relationship of equation (13) is generally satisfied, the acceleration sensor 26, the air pressure sensor 22a, etc. of each wheel 14 normally detect acceleration, etc., and the wheel force calculation unit 101 determines the detected value of the acceleration sensor 26, etc. Based on this, it can be determined that the load actually acting on each wheel 14 is accurately calculated. On the contrary, when the vehicle 10 is steered, the load on any one of the wheels 14 calculated by the wheel force calculation unit 101 based on the detection value of the acceleration sensor 26 or the like is one of the above formulas (10) to (13). If the above condition is not satisfied, the acceleration sensor 26 or the like of any one of the wheels 14 does not detect the acceleration or the like normally, and the wheel force calculation unit 101 may not calculate the load accurately for the wheel 14. .

As described above, when the vehicle 10 is steered, the load acting on the front wheels and the rear wheels due to the steering varies from the load during steady running by an amount (load variation) obtained from the equations (8) and (9). In view of this point, in the present embodiment, the determination unit 103 of the ECU 100 calculates the wheel force calculation unit 101 based on the force balance conditions of the above formulas (10) to (13) established when the vehicle 10 is steered. It is determined whether or not the value is calculated based on acceleration or the like normally detected by the acceleration sensor 26 or the like. Further, as can be seen from the equations (10) to (13), the loads Lfr ₀ , Lfl ₀ , Lrr ₀ and Lrl ₀ acting on each wheel 14 during steady running and the above equations (8) and (9) are obtained. By using the load fluctuations of the front wheels and the rear wheels, it is possible to estimate the load acting on each wheel 14 when the vehicle 10 is steered. In view of this, the wheel force estimation unit 102 of the ECU 100, in addition to the wheel force calculation unit 101, includes known parameters such as front and rear treads df and dr, wheel base l, front and rear roll rigidity Kf and Kr, and distance hs. In addition to using the detected value of the lateral G sensor 113, the load acting on each wheel 14 is estimated based on the equations (10) to (13).

Further, when the vehicle 10 is linearly accelerated or decelerated, the following equations (14) and (15) are established.
Lfr = Lfl (14)
Lrr = Lrl (15)

  Therefore, when the vehicle 10 is linearly accelerated or decelerated, the load acting on each wheel 14 calculated by the wheel force calculation unit 101 based on the detection value of the acceleration sensor 26 and the like is expressed by the above equations (14) and (15). If the relationship is generally satisfied, the acceleration sensor 26 and the like of each wheel 14 normally detects acceleration and the like, and the wheel force calculation unit 101 actually acts on the wheel 14 based on the detection value of the acceleration sensor 26 and the like. It can be determined that the load being calculated is accurately calculated. On the contrary, when the vehicle 10 is linearly accelerated or decelerated, the load acting on each wheel 14 calculated based on the detection value of the acceleration sensor 26 and the like by the wheel force calculation unit 101 is expressed by the above formulas (14) and (15). If any of the above conditions is not satisfied, the acceleration sensor 26 or the like of any of the wheels 14 may not normally detect the acceleration or the like, and the wheel force calculation unit 101 may not calculate the load accurately for the wheel 14. There is.

  Thus, when the vehicle 10 is linearly accelerated or decelerated, the loads acting on the left and right front wheels of the vehicle 10 are substantially equal, and the loads acting on the left and right rear wheels are also substantially equal. In view of this point, in the present embodiment, the wheel force calculation unit 101 is determined by the determination unit 103 of the ECU 100 based on the load balancing conditions of the above expressions (14) and (15) that are satisfied when the vehicle 10 is traveling straight ahead. Is calculated based on the acceleration or the like normally detected by the acceleration sensor 26 or the like.

  Further, when the vehicle 10 is linearly accelerated or decelerated, the following equations (16) and (17) are established.

In the equations (16) and (17), h: height of the center of gravity of the vehicle from the road surface, e: distance between the vertical load application point and the center of the tire contact portion, a _y : longitudinal acceleration of the vehicle 10 . The “vertical load application force point e” can be obtained from the following equation.
e = (Rolling resistance coefficient) × (wheel radius)

  Therefore, if the above formulas (14) to (17) are used, it is possible to estimate the load acting on each wheel 14 when the vehicle 10 is traveling straight ahead. In view of this, the wheel force estimation unit 102 of the ECU 100 uses a known parameter, a detection value of the front / rear G sensor 112, and the like separately from the wheel force calculation unit 101, and based on the equations (14) to (17). The load acting on each wheel 14 is estimated.

  FIG. 9 shows a procedure of determination processing relating to the load executed by the determination unit 103 of the ECU 100, that is, based on the acceleration or the like in which the calculated load value by the wheel force calculation unit 101 is normally detected by the acceleration sensor 26 of the wheel 14. It is a flowchart for demonstrating the procedure which determines whether it is what was calculated. The routine shown in the figure is repeatedly executed by the determination unit 103 every predetermined time. When the execution timing of the routine of FIG. 9 is reached, the determination unit 103 acquires the steering angle of the vehicle 10 via the steering angle sensor 110 and determines whether or not the steering angle exceeds a predetermined threshold θ, that is, the vehicle 10. Is determined to be in the steering state (S40).

If the determination unit 103 determines that the steering angle exceeds the threshold θ (Yes in S40), the loads Lfr, Lfl, Lrr, and Lrl of the wheels 14 calculated at that time from the wheel force calculation unit 101, For example, the load fluctuations ΔLf and ΔLr with respect to the steady running of the front wheels and the rear wheels when the vehicle 10 is in the steering state, which is calculated by the wheel force estimation unit 102 according to the above equations (8) and (9), are acquired (S42). ). Further, the determination unit 103 determines whether or not the load balancing conditions of the above expressions (10) to (13) are generally satisfied with respect to the loads Lfr, Lfl, Lrr and Lrl and the load fluctuations ΔLf and ΔLr acquired in S42. Is determined (S44). It should be noted that the loads Lfr ₀ , Lfl ₀ , Lrr ₀ and Lrl _{0 that} are applied to each wheel 14 during steady running required in S 44 are calculated by the wheel force calculation unit 101 during steady running immediately after the vehicle 10 starts running, for example. Are stored in a predetermined storage area.

  When it is determined that the load balancing conditions of the above equations (10) to (13) are generally satisfied with respect to the loads Lfr, Lfl, Lrr and Lrl and the load fluctuations ΔLf and ΔLr acquired in S42 (in S44) Yes), as described above, the acceleration sensor 26 and the like of each wheel 14 normally detects acceleration and the like, and the wheel force calculation unit 101 actually acts on each wheel 14 based on the detection value of the acceleration sensor 26 and the like. The loads Lfr, Lfl, Lrr and Lrl being calculated are calculated with high accuracy. Therefore, when an affirmative determination is made in S44, the determination unit 103 turns on a predetermined flag indicating that the loads Lfr, Lfl, Lrr and Lrl calculated by the wheel force calculation unit 101 are valid (S46). ). Thereby, when the vehicle integration control or the like is performed by the ECBECU 200, the loads Lr, Lfl, Lrr and Lrl calculated by the wheel force calculation unit 101 of the ECU 100 are used.

  On the other hand, regarding the loads Lfr, Lfl, Lrr and Lrl and the load fluctuations ΔLf and ΔLr acquired in S42, it is determined that any of the load balancing conditions of the above formulas (10) to (13) is not satisfied. If it is to be performed (No in S44), as described above, the acceleration sensor 26 or the like of any of the wheels 14 has not detected the acceleration or the like normally, and the wheel force calculation unit 101 for the wheel 14 has a load accurately. It is not calculated. Therefore, when a negative determination is made in S44, the determination unit 103 sets a predetermined flag indicating that the loads Lfr ′, Lfl ′, Lrr ′ and Lrl ′ estimated by the wheel force estimation unit 102 are valid. Turns on (S48).

  Thereby, when a negative determination is made in S44, that is, the calculated value of the load by the wheel force calculation unit 101 for any one of the wheels 14 by the determination unit 103 is changed to an acceleration or the like normally detected by the acceleration sensor 26 or the like. If it is determined that the calculated value is not calculated based on the lateral force Lfr ′, Lfl ′, Lrr ′ and Lrr ′ estimated by the wheel force estimation unit 102 of the ECU 100 when the ECBECU 200 performs vehicle integration control or the like. Will be. When a predetermined flag indicating that the load estimated by the wheel force estimation unit 102 is valid is turned on in S48, all the calculated values of the load by the wheel force calculation unit 101 are invalidated, and all wheels 14, the estimated load value by the wheel force estimation unit 102 may be output from the ECU 100. Further, when the flag of S48 is turned ON, the acceleration sensor 26 or the like has not normally detected acceleration or the like, and only for the wheel 14 for which it has been determined that the load is not accurately calculated by the wheel force calculation unit 101, An estimated load value by the wheel force estimation unit 102 may be output from the ECU 100.

On the other hand, the determination unit 103, the steering angle is not less than the threshold theta, (No in S40) when the vehicle 10 is determined to be in the straight traveling state, it acquires the longitudinal acceleration _{a x} of the vehicle 10 via a front-rear G sensor 112 _Then , based on the longitudinal acceleration ax, it is determined whether or not the vehicle 10 is in an acceleration state or a deceleration state (S50). When determining unit 103 determines that vehicle 10 is in an accelerating state or a decelerating state (Yes in S50), loads Lfr, Lfl, Lrr, and Lrl of wheels 14 calculated at that time from wheel force calculating unit 101 are determined. Obtain (S52). Further, the determination unit 103 determines whether or not both of the expressions (14) and (15) are generally satisfied with respect to the loads Lfr, Lfl, Lrr, and Lrl acquired in S52 (S54).

  When it is determined that both of the above formulas (14) and (15) are generally satisfied with respect to the loads Lr, Lfl, Lrr and Lrl acquired in S52 (Yes in S54), as described above, each wheel 14 acceleration sensors 26 and the like normally detect acceleration and the like, and the wheel force calculation unit 101 loads Lfr, Lfl, and Lrr actually acting on each wheel 14 based on the detection values of the acceleration sensor 26 and the like. And Lrl are calculated with high accuracy. Therefore, when an affirmative determination is made in S54, the determination unit 103 turns on a predetermined flag indicating that the loads Lfr, Lfl, Lrr, and Lrl calculated by the wheel force calculation unit 101 are valid (S46). ). Thus, when the vehicle integration control or the like is performed by the ECBECU 200, the loads Lfr, Lfl, Lrr and Lrl calculated by the wheel force calculation unit 101 of the ECU 100 are used.

  On the other hand, when it is determined that at least one of the above formulas (14) and (15) is not satisfied with respect to the loads Lfr, Lfl, Lrr and Lrl acquired in S52 (No in S54), As described above, the acceleration sensor 26 or the like of any one of the wheels 14 does not normally detect acceleration or the like, and the load is not accurately calculated by the wheel force calculation unit 101 for the wheel 14. For this reason, even when a negative determination is made in S54, the determination unit 103 is a predetermined flag indicating that the loads Lfr ', Lfl', Lrr 'and Lrl' estimated by the wheel force estimation unit 102 are valid. Is turned on (S48). As a result, even when a negative determination is made in S54, the loads Lfr ′, Lfl ′, Lrr ′ and Lrl ′ estimated by the wheel force estimation unit 102 of the ECU 100 are used in the vehicle integration control or the like by the ECBECU 200. become.

  As described above, in the vehicle 10 of the present embodiment, the calculated values of the loads on the wheels 14 by the wheel force calculation unit 101 are also normally detected by the determination unit 103 by the acceleration sensor 26 and the like. Processing for determining whether or not the calculation is based on acceleration or the like is performed. As a result, it is possible to determine whether or not the calculated value of the load by the wheel force calculation unit 101 accurately indicates the load actually acting on the wheel 14, so that disturbance is applied to the wheel 14 and the acceleration sensor 26 is applied. Even if the acceleration sensor 26 or the like does not normally detect acceleration or the like due to deterioration in the detection accuracy or the like, or the occurrence of an abnormality in the acceleration sensor 26 or the like of the wheel 14, the information related to the wheel 14 It is possible to appropriately process the calculated load value by the wheel force calculation unit 101. That is, in the vehicle 10, it is possible to suppress the vehicle control from being performed based on the calculated value of the wheel force calculation unit 101 that does not accurately indicate the load actually acting on the wheel 14, and in such a case The vehicle 10 can be appropriately controlled using the estimated lateral force value by the wheel force estimating unit 102.

  In addition, as described above, according to the steering state and acceleration / deceleration state of the vehicle 10, the balance condition considering the load variation from the steady running of the load acting on the front wheels and the rear wheels, or between the left and right wheels By executing the determination process based on the load balancing condition (S44 or S54), the calculated load value by the wheel force calculation unit 101 is calculated based on the acceleration or the like normally detected by the acceleration sensor 26. It is possible to accurately determine whether or not there is.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIG. The same elements as those described in relation to the first embodiment described above are denoted by the same reference numerals, and redundant description is omitted.

  As described in relation to the first embodiment, the load in the wheel height direction acting on each wheel 14 of the vehicle 10 may be other than using the acceleration detected by the acceleration sensor 26 of the wheel 14. Can be calculated with relatively high accuracy based on the parameters (time-series data from various sensors). Similarly, the lateral force in the wheel width direction acting on each wheel 14 of the vehicle 10 can be calculated with relatively high accuracy based on other parameters without using the acceleration detected by the acceleration sensor 26 of the wheel 14. it can. Therefore, the wheel force estimation unit 102 of the ECU 100 described above does not use the detection value of the acceleration sensor 26 of the wheel 14 or the like, but the lateral force and load acting on each wheel 14 based on other parameters (time series data by various sensors). Can be configured to estimate.

  In such a case, even if the deviation between the calculated value of the wheel force calculating unit 101 and the estimated value of the wheel force estimating unit 102 is used as a criterion, the calculated value of the wheel force calculating unit 101 actually acts on the wheel 14. It is possible to discriminate whether or not the lateral force and the load are accurately indicated. In the following description, the lateral force and load acting on each wheel 14 calculated by the wheel force calculating unit 101 are referred to as Fc and Lc, respectively, and the lateral force acting on each wheel 14 estimated by the wheel force estimating unit 102 and The loads are referred to as Fe and Le, respectively.

  FIG. 10 illustrates a wheel information processing apparatus according to the second embodiment in which the calculated values of the lateral force and the load by the wheel force calculation unit 101 are calculated based on the acceleration or the like normally detected by the acceleration sensor 26 of the wheel 14. It is a flowchart for demonstrating the procedure which determines whether it is a thing. The routine shown in the figure is also repeatedly executed every predetermined time by the determination unit 103 of the ECU 100 for each of the plurality of wheels 14. When the execution timing of the routine of FIG. 10 is reached, the determination unit 103 acquires the lateral force Fc and the load Lc of the corresponding wheel 14 calculated at that time from the wheel force calculation unit 101 (S60), and estimates the wheel force. The lateral force Fe and load Le of the corresponding wheel 14 estimated at that time are acquired from the unit 102 (S62).

After the processing of S62, the determination unit 103 determines the deviation ΔF between the lateral force calculation value Fc by the wheel force calculation unit 101 and the lateral force estimation value Fe by the wheel force estimation unit 102 and the load by the wheel force calculation unit 101. A deviation ΔL between the calculated value Lc and the estimated value Le of the load by the wheel force estimating unit 102,
ΔF = | Fc | − | Fe |
ΔL = | Lc | − | Le |
Respectively (S64).

  Next, the determination unit 103 determines whether or not the deviation ΔF related to the lateral force calculated in S64 is greater than a predetermined threshold γ1 (S66). When it is determined that the deviation ΔF related to the lateral force exceeds the threshold γ1 (Yes in S66), the determination unit 103 further determines that the deviation ΔF related to the lateral force calculated in S64 is a predetermined threshold γ2 (however, γ2 > Γ1) is determined (S68). If it is determined that the deviation ΔF related to the lateral force is below the threshold γ2, that is, if the deviation ΔF related to the lateral force is determined to be within a predetermined range (γ1 <ΔF <γ2) (Yes in S68), the determination In the unit 103, the acceleration sensor 26 or the like of the wheel 14 detects the acceleration or the like normally. In the wheel force calculation unit 101, the lateral force actually acting on the wheel 14 based on the detection value of the acceleration sensor 26 or the like. Is calculated with high accuracy, and a predetermined flag indicating that the lateral force calculation value Fc by the wheel force calculation unit 101 is valid is turned ON (S70).

  On the other hand, when it is determined that the deviation ΔF related to the lateral force is equal to or less than the threshold value γ1, that is, the absolute value of the lateral force calculated value Fc by the wheel force calculating unit 101 is equal to the lateral force estimated value Fe of the wheel force estimating unit 102. If the absolute value is below a certain level (No in S66), it may be considered that the detection accuracy of the acceleration sensor 26 and the like provided on the wheel 14 is deteriorated due to factors such as sensor abnormality and deterioration of the surrounding environment. it can. Accordingly, when a negative determination is made in S66, the determination unit 103 turns on a predetermined flag indicating that the lateral force estimation value Fe by the wheel force estimation unit 102 is valid (S72).

  When it is determined that the deviation ΔF related to the lateral force is greater than or equal to the threshold γ2, that is, the absolute value of the lateral force calculated value Fc by the wheel force calculating unit 101 is equal to the lateral force estimated value Fe of the wheel force estimating unit 102. If the absolute value is exceeded to some extent (No in S68), it can be considered that a disturbance due to road surface unevenness acts on the wheel 14 and the detected value of the acceleration sensor 26 shows an excessive value. it can. Accordingly, even when a negative determination is made in S68, the determination unit 103 turns on a predetermined flag indicating that the lateral force estimation value Fe by the wheel force estimation unit 102 is valid (S72).

  After the process of S70 or S72, the determination unit 103 determines whether or not the deviation ΔL related to the load calculated in S64 exceeds a predetermined threshold value κ1 (S74). When it is determined that the deviation ΔL related to the load exceeds the threshold κ1 (Yes in S74), the determination unit 103 further determines the deviation ΔL related to the load calculated in S64 as a predetermined threshold κ2 (where κ2> κ1). It is determined whether it is below (S76). If it is determined that the load-related deviation ΔL is below the threshold κ2, that is, if the load-related deviation ΔL is determined to be within a predetermined range (κ1 ≦ ΔL ≦ κ2) (Yes in S76), the determination unit 103 The acceleration sensor 26 and the like of the wheel 14 has normally detected acceleration and the wheel force calculation unit 101 accurately detects the load actually acting on the wheel 14 based on the detection value of the acceleration sensor 26 and the like. A predetermined flag indicating that the calculated load value Lc by the wheel force calculation unit 101 is valid is turned on (S78).

  On the other hand, when it is determined that the deviation ΔL related to the load is equal to or less than the threshold value κ1, that is, the absolute value of the load calculated value Lc by the wheel force calculating unit 101 is the absolute value of the load estimated value Le by the wheel force estimating unit 102. If it is below a certain level (No in S74), it can be considered that the detection accuracy of the acceleration sensor 26 and the like provided on the wheel 14 is deteriorated due to factors such as sensor abnormality and deterioration of the surrounding environment. Accordingly, when a negative determination is made in S74, the determination unit 103 turns on a predetermined flag indicating that the estimated load value Le of the wheel force estimation unit 102 is valid (S80).

  When it is determined that the deviation ΔL related to the load is equal to or greater than the threshold κ2, that is, the absolute value of the load calculated value Lc by the wheel force calculating unit 101 is the absolute value of the load estimated value Le by the wheel force estimating unit 102. If it exceeds a certain level (No in S76), it can be considered that a disturbance caused by road surface unevenness or the like acts on the wheel 14 and the detected value of the acceleration sensor 26 shows an excessive value. Accordingly, even when a negative determination is made in S76, the determination unit 103 turns on a predetermined flag indicating that the estimated load value Le of the wheel force estimation unit 102 is valid (S80).

  In this way, when the flag that defines which one of the calculated value of the wheel force calculating unit 101 and the estimated value of the wheel force estimating unit 102 is effective for the lateral force and the load is set, the determining unit 103 responds to the flag. Then, the calculated values or estimated values of the lateral force and load are output to the ECBECU 200 or the like (S82), and the above flags are reset (S84).

  As a result, even in the vehicle 10 equipped with the wheel information processing apparatus according to the second embodiment, acceleration or the like is not normally detected by the acceleration sensor 26 or the like provided on the wheel 14 due to disturbance or failure. In this case, a flag indicating that the force estimated by the wheel force estimating unit 102 is valid is turned ON, and the force calculated value by the wheel force calculating unit 101 is invalidated. Thereby, it is possible to suppress the vehicle control from being performed based on the calculated value of the wheel force calculation unit 101 that does not accurately indicate the lateral force actually acting on the wheel 14. In such a case, not the calculated value of the wheel force calculating unit 101 but the estimated value of the wheel force estimating unit 102 is used for vehicle control. Therefore, even when acceleration or the like is not normally detected by the acceleration sensor 26 or the like due to disturbance or failure, the vehicle 10 is appropriately used by using the estimated value of the force actually acting on the wheels 14. It becomes possible to control to. Further, when the routine of FIG. 10 is adopted, the fact that acceleration or the like is not normally detected by the acceleration sensor 26 or the like is due to an abnormality in the acceleration sensor 26 or the like, or due to a disturbance acting on the wheel 14. It is also possible to determine whether or not.

[Third Embodiment]
Hereinafter, a third embodiment of the present invention will be described with reference to FIG. The same elements as those described in relation to the first embodiment described above are denoted by the same reference numerals, and redundant description is omitted.

  In general, when the vehicle 10 rides over a so-called cleat, pothole, or curb, the tire 18 constituting the wheel 14 is greatly deformed three-dimensionally. Therefore, the acceleration sensor 26 provided on the wheel 14 or the like is used. The acceleration or the like may not be detected with high accuracy. Further, when the vehicle 10 gets over a so-called cleat, pothole or curb, the sprung acceleration of the vehicle 10, that is, the vertical acceleration of the vehicle body 12, increases and exceeds a certain threshold. Therefore, even if the detection value of the sprung G sensor 115 that detects the sprung acceleration of the vehicle 10 is used as the determination criterion, the lateral force and the load calculated by the wheel force calculation unit 101 actually act on the wheel 14. It is possible to determine whether the lateral force and the load are accurately indicated.

  FIG. 11 illustrates a wheel information processing apparatus according to the third embodiment, in which the calculated values of lateral force and load by the wheel force calculation unit 101 are calculated based on the acceleration normally detected by the acceleration sensor 26 of the wheel 14. It is a flowchart for demonstrating the procedure which determines whether it is a thing. The routine shown in the figure is also repeatedly executed at predetermined intervals by the determination unit 103 of the ECU 100. At the execution timing of the routine of FIG. 11, the determination unit 103 acquires the unsprung acceleration ad of the vehicle 10 from the acceleration sensor 22 g of the TPMS valve 20 and also acquires the unsprung acceleration au of the vehicle 10 from the sprung G sensor 115. (S90). Furthermore, the determination unit 103 determines whether or not the unsprung acceleration ad of the vehicle 10 exceeds a predetermined threshold value δ1 (S92).

  When determining that the unsprung acceleration ad of the vehicle 10 exceeds the threshold value δ1 (Yes in S90), the determination unit 103 further determines whether or not the sprung acceleration au of the vehicle 10 exceeds a predetermined threshold value δ2. Is determined (S94). When it is determined that the unsprung acceleration ad of the vehicle 10 exceeds the threshold δ1 and the sprung acceleration au of the vehicle 10 exceeds the threshold δ2 (Yes in S94), the determination unit 103 determines that the vehicle 10 It is assumed that the vehicle has overtaken a cleat, a pothole, or a curb, and that acceleration or the like cannot be accurately detected by the acceleration sensor 26 or the like provided on the wheel 14, and is estimated by the wheel force estimation unit 102. A predetermined flag indicating that the lateral force or load is valid is turned ON (S96). Thereby, when it is determined by the determination unit 103 that the lateral force or load calculation value by the wheel force calculation unit 101 is not calculated based on the acceleration or the like normally detected by the acceleration sensor 26 or the like, When the vehicle integration control or the like is performed by the ECBECU 200, a lateral force or a load estimated by the wheel force estimation unit 102 of the ECU 100 is used.

  On the other hand, when it is determined that the unsprung acceleration ad of the vehicle 10 is equal to or less than the threshold value δ1 (No in S92), and when it is determined that the sprung acceleration au of the vehicle 10 is equal to or less than the threshold value δ2 (S94). No), the determination unit 103 regards that acceleration or the like is accurately detected by the acceleration sensor 26 or the like provided on the wheel 14, and that the lateral force or load calculated by the wheel force calculation unit 101 is valid. Is turned on (S98). Thereby, in these cases, the lateral force and the load calculated by the wheel force calculation unit 101 of the ECU 100 are used in the vehicle integration control or the like by the ECBECU 200.

  Thus, even if the detection value of the sprung G sensor 115 that detects the sprung acceleration of the vehicle 10 is used as a criterion, the calculated values of the lateral force and the load by the wheel force calculation unit 101 actually act on the wheels 14. It can be discriminated whether the lateral force and the load are accurately indicated. Thereby, also in the vehicle 10 provided with the wheel information processing apparatus of the present embodiment, when a disturbance is applied to the wheel 14 and the detection accuracy of the acceleration sensor 26 or the like deteriorates, the lateral force of the wheel force calculation unit 101 is reduced. The calculated value can be appropriately processed.

It is a schematic block diagram which shows the vehicle provided with the wheel information processing apparatus by this invention. It is a fragmentary sectional view which shows the wheel with which the vehicle of FIG. 1 was equipped. It is a schematic diagram which shows the arrangement | positioning aspect of the acceleration sensor in the tire of the wheel with which the vehicle of FIG. 1 was equipped. It is a control block diagram of the wheel information processing apparatus by this invention. 2 is a flowchart showing a routine for obtaining a lateral force in a tire width direction acting on a tire in the vehicle of FIG. 1. It is a schematic diagram which shows the relationship between the ground contact state of a tire and the acceleration waveform obtained from the detected value of the acceleration provided in the tire. In the vehicle of FIG. 1, a procedure for determining whether or not the calculated value of the lateral force by the wheel force calculation unit is calculated based on the acceleration or the like normally detected by the wheel acceleration sensor is described. It is a flowchart. 2 is a flowchart for explaining a procedure for calculating a vehicle mass and a yaw moment of inertia in a state where an occupant gets in the vehicle of FIG. 1. The flowchart for demonstrating whether the calculated value of the load by the wheel force calculation part is calculated based on the acceleration etc. which were normally detected by the acceleration sensor of a wheel in the vehicle of FIG. It is. In the second embodiment of the present invention, a procedure for determining whether or not the calculated values of the lateral force and the load by the wheel force calculation unit are calculated based on the acceleration or the like normally detected by the wheel acceleration sensor. It is a flowchart for demonstrating. In the third embodiment of the present invention, a procedure for determining whether or not the calculated values of the lateral force and the load by the wheel force calculation unit are calculated based on the acceleration or the like normally detected by the wheel acceleration sensor. It is a flowchart for demonstrating.

Explanation of symbols

  10 vehicle, 12 vehicle body, 14 wheel, 16 wheel, 18 tire, 20 TPMS valve, 22a air pressure sensor, 22g acceleration sensor, 23 TPMS communication machine, 24 control circuit, 25, 29 battery, 26 acceleration sensor, 27 amplifier, 28 communication 30, vehicle body side communication device, 100 ECU, 101 wheel force calculation unit, 102 wheel force estimation unit, 103 determination unit, 104 storage device, 105 alarm device, 110 steering angle sensor, 111 wheel speed sensor, 112 front and rear G sensor, 113 lateral G sensor, 114 yaw rate sensor, 115 sprung G sensor, 183 tread portion, 188 tire internal space, 200 ECBECU.

Claims (14)

In a wheel information processing apparatus for processing information related to a vehicle wheel,
Detecting means provided on the wheel for detecting a predetermined physical quantity;
Wheel force calculation means for calculating a force acting on the wheel based on a detection value of the detection means;
A wheel information processing apparatus comprising: determining means for determining whether or not the calculated value of the wheel force calculating means is calculated based on the physical quantity normally detected by the detecting means.   When the determination means determines that the calculated value of the wheel force calculation means is not calculated based on the physical quantity normally detected by the detection means, the calculated value of the wheel force calculation means is invalidated. The wheel information processing apparatus according to claim 1, further comprising: The vehicle has a plurality of wheels, and the detection means is provided for each of the plurality of wheels,
The wheel force calculation means calculates a force acting on a wheel for each of the plurality of wheels based on a detection value of the detection means,
The determination means determines, for each of the plurality of wheels, whether the calculated value of the wheel force calculation means is calculated based on the physical quantity normally detected by the detection means,
When the determination means determines that the calculated value of the wheel force calculation means for any wheel is not calculated based on the physical quantity normally detected by the detection means, the detection means Wheel force estimating means for estimating a force acting on any of the wheels based on a calculated value of the wheel force calculating means determined to be calculated based on the normally detected physical quantity. The wheel information processing apparatus according to claim 1 or 2.   The determination means is based on the physical quantity in which the calculated value of the wheel force calculation means is normally detected by the detection means, based on a balance condition of forces acting on the wheels established according to the running state of the vehicle. 4. The wheel information processing apparatus according to claim 1, wherein it is determined whether or not the information is calculated in the above manner.   The wheel force calculating means calculates a lateral force in a wheel width direction that acts on each wheel of the vehicle based on a detection value of the detecting means, and the determining means determines the left and right according to the steering state of the vehicle. The calculated value of the wheel force calculation means is calculated based on the physical quantity normally detected by the detection means based on the balance condition of the lateral force between the wheels or the balance condition of the lateral force between the front and rear wheels. It is determined whether it is a thing, The wheel information processing apparatus of Claim 4 characterized by the above-mentioned.   The detection means is an acceleration acquisition means that is provided in a plurality in the wheel circumferential direction with respect to the wheel and is provided in a plurality of rows in the wheel width direction, and obtains acceleration in the predetermined direction of the wheel based on each detection value. And the wheel force calculating means calculates the lateral force based on a ratio between the contact lengths of the wheels in the longitudinal direction of the vehicle obtained from the detection values of the acceleration acquiring means in each row. Wheel information processing apparatus according to claim 1.   The wheel force calculating means calculates a load in a wheel height direction acting on each wheel of the vehicle based on a detection value of the detecting means, and the determining means is based on steering according to a running state of the vehicle. The calculated value of the wheel force calculation means is calculated based on the physical quantity normally detected by the detection means, based on the balance condition of the load considering the load variation or the balance condition of the load between the left and right wheels. It is determined whether it is a thing, The wheel information processing apparatus of Claim 4 characterized by the above-mentioned. The detection means is an acceleration acquisition means that is arranged in a plurality in at least the wheel circumferential direction with respect to the wheel, and obtains acceleration in a predetermined direction of the wheel based on each detected value.
The wheel force calculation means calculates the load based on a ground contact length of the wheel in the vehicle longitudinal direction obtained from a detection value of each acceleration acquisition means of the wheel and an air pressure of a tire constituting the wheel. 8. The wheel information processing apparatus according to claim 7, wherein   In addition to the wheel force calculation means, wheel force estimation means for estimating a force acting on the wheel is further provided, and the determination means is a deviation between the calculated value of the wheel force calculation means and the estimated value of the wheel force estimation means. The method according to claim 1, wherein it is determined whether or not the calculated value of the wheel force calculating means is calculated based on the physical quantity normally detected by the detecting means. The wheel information processing apparatus described.   When the deviation between the calculated value of the wheel force calculating means and the estimated value of the wheel force estimating means is within a predetermined range, the determining means detects the calculated value of the wheel force calculating means normally by the detecting means. The wheel information processing apparatus according to claim 9, wherein the wheel information processing apparatus is determined to be calculated based on the physical quantity.   The apparatus further comprises sprung acceleration detecting means for detecting the sprung acceleration of the vehicle, and the determining means determines that the calculated value of the wheel force calculating means is normal by the detecting means based on the detected value of the sprung acceleration detecting means. The wheel information processing apparatus according to any one of claims 1 to 3, wherein it is determined whether or not the physical quantity is calculated based on the physical quantity detected in step (b).   The apparatus further comprises unsprung acceleration detecting means for detecting unsprung acceleration of the vehicle, wherein the determining means has a detected value of the unsprung acceleration detecting means exceeding a predetermined threshold value, and a detected value of the unsprung acceleration detecting means. 12. When the value exceeds a predetermined threshold, it is determined that the calculated value of the wheel force calculating means is not calculated based on the physical quantity normally detected by the detecting means. Wheel information processing apparatus according to claim 1.   The said detection means is an acceleration sensor which is arrange | positioned in the tread part inner surface of the tire which comprises the said wheel, and detects the acceleration of the said tire in a wheel circumferential direction or a wheel radial direction. The wheel information processing apparatus according to any one of the above. In a wheel information processing method for processing information related to a vehicle wheel,
(A) detecting a predetermined physical quantity of the wheel using detection means provided on the wheel;
(B) calculating a force acting on the wheel based on a detection value of the detection means;
(C) A wheel information processing method including a step of determining whether or not the calculated value in step (b) is calculated based on the physical quantity normally detected by the detecting means.

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