JP2006062381A - Air pressure control device of a tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air pressure control device of a tire which eliminates deflection of a vehicle by generating rotational moment in the direction of eliminating the deflection of the vehicle around the center of gravity of the vehicle through a changing ratio of air pressure of left and right tires due to change in air pressure of each tire. <P>SOLUTION: The air pressure control device 20 of the tire estimates a target yaw rate γ<SB>0</SB>from a vehicle speed V and a steering angle θ, acquire a plurality of data D(n) to be difference between the target yaw rate γ<SB>0</SB>and a real yaw rate γ, acquires an average value Dave from the plurality of the acquired data D (n), and estimates the deflection direction and amount of deflection of the vehicle based on the acquired average value Dave. The air pressure control device 20 of the tire generates the rotational moment M in the direction of eliminating the deflection of the vehicle around the center of gravity of the vehicle by changing the air pressure of the tire in accordance with the average value Dave. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tire air pressure control device that extinguishes a deflection state of a vehicle by controlling the air pressure of a tire included in the vehicle.

When the vehicle is traveling on an asphalt road surface, wheels on either the left or right side of the vehicle (for example, the left front wheel and the left rear wheel) may pass through the frozen portion on the road surface. In this case, since the friction coefficient of the road surface is significantly different between the left and right sides of the vehicle, the vehicle automatically starts turning. Further, when the vehicle suddenly receives a crosswind immediately after passing through the tunnel, the vehicle automatically starts turning. In such a case, the conventional apparatus drives the electric motor of the electric power steering apparatus to automatically steer the tire, and generates a rotational moment in the direction opposite to the automatic turning direction of the vehicle around the center of gravity of the vehicle. Thereby, the conventional apparatus can suppress the automatic turning of a vehicle (for example, refer patent document 1).
Japanese Patent Laying-Open No. 2004-90878 (paragraph numbers 0017 to 0019, FIG. 3)

  By the way, the vehicle is not only affected by the disturbance that changes the behavior of the vehicle relatively abruptly as described above, but also when traveling while constantly receiving a crosswind or traveling on a canted road surface. Sometimes, it may be continuously affected by disturbances over a relatively long period of time. In such a case, a rotational force is constantly generated around the center of gravity of the vehicle by applying a lateral force to the vehicle body. In addition, the rotational moment may be constantly generated due to the state of the vehicle such as the tire PRCF (price tear residual component cornering force) caused by the alignment setting state and the tread pattern.

  In this way, it is said that the vehicle deflects that the vehicle turns slowly as a result of the rotation moment generated around the center of gravity of the vehicle due to factors other than the steering of the driver, and the direction of the generated rotation moment is the direction of the vehicle deflection. That's it.

  When such a conventional deflection occurs, the conventional device continuously drives the electric motor to maintain the tire turning angle different from the turning angle determined by the steering angle. . However, if the driver tries to move the vehicle straight and the tire is kept in a steered state, the steering wheel mechanically connected to the tire (and thus the wheel) is not at a predetermined position other than the neutral position. Will be maintained at an angle. As a result, the vehicle has a steering off center (that is, a state in which the steering wheel is deviated from the neutral position even though the vehicle is traveling straight), which causes the driver to feel uncomfortable.

  Therefore, an object of the present invention is to provide a tire pressure control device that can eliminate the deflection (deflection state) of a vehicle without causing a steering off center by changing the tire pressure.

The tire pressure control device of the present invention is made to achieve the above object,
A tire pressure changing device for changing at least one of the plurality of tires provided in the vehicle according to the instruction signal;
Driving state detecting means for detecting the driving state of the vehicle;
Deflection state value acquisition means for acquiring a deflection state value which is a value representing the deflection state of the vehicle based on the detected driving state;
Control means for sending the instruction signal to the tire air pressure changing device so that a rotational moment in a direction for eliminating the deflection state of the vehicle represented by the acquired deflection state value is generated in the vehicle;
It has.
Here, the deflection state value is a value indicating at least the deflection direction of the vehicle.

  According to this, a deflection state value that is a value representing the deflection state of the vehicle is acquired based on the driving state of the vehicle, and the rotational moment in a direction to extinguish the deflection state of the vehicle represented by the acquired deflection state value The air pressure of at least one tire is changed so that is generated in the vehicle. On the other hand, even if the tire air pressure is changed, the relationship between the steering angle of the steering wheel and the turning angle of the tire is not changed. Therefore, this tire pressure control device can eliminate the deflection of the vehicle without causing a steering off center.

  In order to cause the vehicle to generate a rotational moment (around the center of gravity of the vehicle) by changing the tire air pressure, the ratio of the left and right tire air pressures may be changed. For example, when the direction of deflection of the vehicle is the left direction, the left tire (left front wheel tire and / or left rear wheel tire) is selected to increase the air pressure of the selected tire and / or the right tire A tire (right front wheel tire and / or right rear wheel tire) is selected to reduce the air pressure of the selected tire. As a result, the ratio of the air pressure of the left tire to the air pressure of the right tire increases from the ratio of the same air pressure before control.

  As a result, the ratio of the rolling resistance of the left tire to the rolling resistance of the right tire decreases, and the ratio of the dynamic load radius of the left tire to the dynamic load radius of the right tire increases. As described above, the left tire generates a force that causes the left side of the vehicle to face forward relative to the right side, and / or the right tire causes the right side of the vehicle to face rearward relative to the left side. Force is generated. As a result, a clockwise (rightward) rotational moment is generated around the center of gravity of the vehicle, and the aforementioned leftward deflection of the vehicle disappears.

in this case,
The operating state detecting means is
Vehicle speed detecting means for detecting the speed of the vehicle;
A steering angle sensor for detecting a steering angle of a steering wheel of the vehicle;
A yaw rate sensor that detects an actual yaw rate that is the yaw rate of the vehicle;
With
The deflection state value acquisition means includes
Based on the detected vehicle speed and the detected steering angle, a target yaw rate that is an ideal yaw rate to be generated in the vehicle when a factor for deflecting the vehicle is not generated is estimated, and the estimation is performed. It is preferable that the deflection state value is acquired based on a difference between the target yaw rate that has been set and the actual yaw rate detected by the yaw rate sensor.

  According to this, a target yaw rate that is an ideal yaw rate is estimated according to the speed and steering angle of the vehicle, and the deflection state value is acquired based on the difference between the estimated target yaw rate and the actual yaw rate. Therefore, the vehicle deflection state value can be acquired not only when the steering wheel is in a substantially neutral state but also when being operated by the driver.

Furthermore, the deflection state value acquisition means includes
The difference between the target yaw rate and the actual yaw rate is obtained every elapse of a predetermined time, and the difference between the target yaw rate and the actual yaw rate obtained every elapse of the predetermined time is averaged over a period longer than the predetermined time. Preferably, the deflection state value is acquired based on the averaged value.

  According to this, the deflection state value of the vehicle is acquired based on a value obtained by averaging the difference between the target yaw rate and the actual yaw rate in terms of time. As a result, the deflection state occurring in the vehicle for a relatively long period of time can be accurately estimated without taking a sudden turn of the vehicle due to a sudden crosswind or the like as the deflection. Therefore, compared with the case where the tire air pressure is changed every time the difference between the target yaw rate and the actual yaw rate is obtained, the vehicle deflection can be gently eliminated without destabilizing the behavior of the vehicle.

Hereinafter, a tire pressure control device according to an embodiment of the present invention will be described with reference to the drawings.
This tire pressure control device is mounted on a vehicle in the form shown in FIG. The vehicle includes a left front tire FL and a right front tire FR disposed on the left and right front sides of the vehicle, a left rear tire RL and a right rear tire RR disposed on the left and right sides of the vehicle, respectively, and a steering wheel 10. A steering shaft 11 and a steering gear box 12 are provided.

  The steering wheel 10, the steering shaft 11, and the steering gear box 12 transmit the rotation of the steering wheel 10 that is rotated by the driver to the steering wheels (in this example, the left front wheel and the right front wheel). It comes to steer.

  The tire air pressure control device 20 includes a tire air pressure changing device 21, an electric control device (control means) 30, a vehicle speed sensor 40, a steering angle sensor 41, and a yaw rate sensor 42.

  The tire pressure changing device 21 includes a pump 21a, an accumulator 21b, an electromagnetic valve 21fl, an electromagnetic valve 21fr, an electromagnetic valve 21rl, and an electromagnetic valve 21rr. The pump 21a compresses air. The accumulator 21b is connected to the pump 21a and accumulates high-pressure air compressed by the pump 21a. The accumulator 21b is connected to the left front tire FL, the right front tire FR, the left rear tire RL, and the right rear tire RR through the electromagnetic valve 21fl, the electromagnetic valve 21fr, the electromagnetic valve 21rl, and the electromagnetic valve 21rr, respectively.

  Each of the electromagnetic valve 21fl, the electromagnetic valve 21fr, the electromagnetic valve 21rl, and the electromagnetic valve 21rr includes an electromagnetic mechanism, and the position of the switching valve is set to the first position (the left end in FIG. 1) and the second by the operation of the electromagnetic mechanism. The position is changed to either the position (center in FIG. 1) or the third position (right end in FIG. 1).

  When the switching valve is in the first position, each solenoid valve communicates the pump 21a and the accumulator 21b with each corresponding tire, and supplies high pressure air in the accumulator 21b to each tire. The air pressure is increased. When each switching valve is in the second position, each solenoid valve blocks communication between the accumulator 21b and each corresponding tire and maintains the air pressure of each tire. Each solenoid valve communicates each tire and the outside through a filter when the switching valve is in the third position, and reduces the air pressure of each tire.

  The electric control device 30 is a microcomputer that mainly includes a CPU 31, a ROM 32, a RAM 33, a back up RAM 34, and an interface 35. A vehicle speed sensor 40, a steering angle sensor 41, and a yaw rate sensor 42 are connected to the interface 35, and the CPU 31 inputs signals from these sensors.

  The vehicle speed sensor 40 outputs a signal corresponding to the vehicle speed (vehicle speed V) by detecting the rotational speed of the wheels or the rotational speed of the output shaft of the transmission.

  The steering angle sensor 41 outputs a signal corresponding to the steering angle θ by detecting the operation amount of the steering wheel 10. The steering angle θ detected by the steering angle sensor 41 is set to a value of “0” when the steering wheel 10 is at the steering angle midpoint (neutral position), and the steering wheel 10 rotates rightward from the steering angle midpoint. A positive value is set when the steering wheel 10 is rotating, and a negative value is set when the steering wheel 10 is rotating leftward from the steering angle midpoint.

  The yaw rate sensor 42 outputs a signal corresponding to the actual yaw rate γ by detecting the actual yaw rate γ (yaw angular velocity) generated around the center of gravity of the vehicle. The actual yaw rate γ is a value of “0” when no yaw rate occurs in the vehicle, a positive value when a clockwise yaw rate occurs, and a negative value when a counterclockwise yaw rate occurs. Is set to The vehicle speed sensor 40 corresponds to vehicle speed detection means. Further, the vehicle speed sensor 40, the steering angle sensor 41, and the yaw rate sensor 42 correspond to driving state detection means for detecting a driving state.

  The interface 35 is connected to an electromagnetic valve 21fl, an electromagnetic valve 21fr, an electromagnetic valve 21rl, an electromagnetic valve 21rr, and a pump 21a. Thereby, CPU31 sends a drive signal (instruction signal) to each solenoid valve and pump 21a.

Next, the operation of the tire pressure control device 20 configured as described above will be described.
(Acquisition of vehicle deflection state value)
First, the operation of the tire pressure control device 20 when acquiring a deflection state value that is a value representing the deflection state of the vehicle will be described with reference to FIG. The value representing the vehicle deflection state is a value representing the vehicle deflection direction and deflection amount (degree of change).

  FIG. 2 is a flowchart showing a routine (program) executed by the CPU 31 of the electric control device 30 shown in FIG. 1 to calculate the deflection state value. The CPU 31 repeatedly executes this program every elapse of a predetermined time.

  The CPU 31 starts the process from step 200 when the predetermined timing comes, proceeds to step 205, reads the vehicle speed V in step 205, and reads the steering angle θ in subsequent step 210.

Next, the CPU 31 proceeds to step 215 to estimate a target yaw rate γ ₀ corresponding to the steering angle θ and the vehicle speed V based on a predetermined target yaw rate estimation map. The target yaw rate is an ideal yaw rate that should be generated in the vehicle in accordance with the steering angle θ and the vehicle speed V when no factor causing the deflection in the vehicle has occurred. Similar to the actual yaw rate γ, the target yaw rate γ ₀ is determined to be a positive value for the clockwise yaw rate and a negative value for the counterclockwise yaw rate.

Next, the CPU 31 proceeds to step 220 to read the actual yaw rate γ, proceeds to step 225 to add “1” to the value n, and proceeds to step 230 to subtract the target yaw rate γ ₀ from the actual yaw rate γ. Data D (n) is obtained. The value n indicates the number of data D (n), and is set to a value of “0” in advance in an initial routine that is executed when the ignition switch is turned on. Next, the CPU 31 proceeds to step 235 to store the data D (n) in the RAM 33, proceeds to step 295, and temporarily ends the processing of this routine.

As shown in FIG. 3, the data D (n) calculated in this way becomes a positive value because the actual yaw rate γ is larger than the target yaw rate γ ₀ when the vehicle is deflected to the right. Is negative, since the actual yaw rate γ is smaller than the target yaw rate γ ₀ . The absolute value of the data D (n) indicates the amount of vehicle deflection. That is, the data D (n) is an individual value indicating the deflection state of the vehicle.

(Tire pressure control)
Next, the operation of the tire pressure control device 20 when controlling the air pressure of the left front tire FL, the right front tire FR, the left rear tire RL, and the right rear tire RR will be described separately with reference to FIG.
FIG. 4 is a flowchart showing a routine (program) executed by the CPU 31 shown in FIG. 1 to control the air pressure of each tire. The CPU 31 repeatedly executes this program every elapse of a predetermined time.

(1) When the vehicle is not deflected First, the case where the driver starts traveling after changing the ignition switch from off to on and the vehicle is not deflected will be described. To do. When the ignition switch is changed from OFF to ON, the CPU 31 starts the process from step 400 when the predetermined timing comes, and proceeds to step 405. In step 405, the calculation is performed in step 225 of FIG. It is determined whether or not the value n is equal to the total number Nsum. The total number Nsum indicates the number of data D (n) necessary for obtaining the average value of the data D (n). Since this time is immediately after the ignition switch is changed from OFF to ON, the value n is not equal to the total number Nsum. Therefore, the CPU 31 makes a “No” determination at step 405 and immediately proceeds to step 495 to end the processing of this routine once.

  Thereafter, since the CPU 31 repeatedly executes the routine shown in FIG. 2, the value n gradually increases (see step 225). Therefore, when the CPU 31 executes the routine shown in FIG. 4 when the predetermined time elapses and the value n becomes equal to the total number Nsum, the CPU 31 determines “Yes” in step 405, and proceeds to step 410. Then, data D (1) to data D (n) are added, and the added value is divided by n, so that the time (period longer than the sampling interval of data D (n)) ΔT shown in FIG. A deflection state value (average value of individual deflection state values D (n)) Dave representing the vehicle deflection state is calculated.

  Next, the CPU 31 determines in step 415 whether or not the deflection state value Dave is equal to “0”. In this case, the deflection state value Dave is “0” because no deflection has occurred in the vehicle based on the assumption described above. Therefore, the CPU 31 determines “Yes” in step 415 and proceeds to step 420. After setting “0” to the value n, the CPU 31 proceeds to step 495 and temporarily ends the processing of this routine. Thus, the air pressure of the tire is not changed unless the vehicle is deflected.

(2) When rightward deflection occurs in the vehicle In this case, the deflection state value Dave is larger than “0”. Accordingly, when the value n becomes equal to the total number Nsum, when the CPU 31 proceeds to step 415, it determines “No” in step 415 and proceeds to step 430 to determine whether the deflection state value Dave is greater than “0”. It is determined whether or not a rightward deflection has occurred in the vehicle.

  As described above, the deflection state value Dave is larger than “0”. Accordingly, the CPU 31 determines “Yes” in step 430 and proceeds to step 435 to apply the absolute value of the deflection state value Dave to the function f to change the tire pressure change amount f (| Dave | ) And the target tire pressure Pfl of the left front tire FL is updated by subtracting the change amount f (| Dave |) from the target tire pressure Pfl of the left front tire FL. Here, the function f is a function for calculating a change amount (control amount) of the tire air pressure with respect to the deflection amount using the deflection amount as a variable, and is a function that monotonously increases with respect to the absolute value of the deflection amount. The function f is set so that the value obtained by the function f is always greater than “0”.

  Further, in step 435, the CPU 31 updates the target tire air pressure Prl of the left rear tire RL by subtracting the change amount f (| Dave |) from the target tire air pressure Prl of the left rear tire RL.

  Further, the CPU 31 updates the target tire pressure Pfr of the right front tire FR by adding the change amount f (| Dave |) to the target tire pressure Pfr of the right front tire FR, and similarly the target tire pressure of the right rear tire RR. The target tire air pressure Prr of the right rear tire RR is obtained by adding the change amount f (| Dave |) to Prr. Then, the CPU 31 sends an instruction signal to the solenoid valve 21fl, the solenoid valve 21fr, the solenoid valve 21rl, and the solenoid valve 21rr so that the air pressure of each tire becomes the updated target tire pressure Pfl, Prl, Pfr, and Prr. send. Thereafter, the CPU 31 proceeds to step 495 via step 420, and once ends the processing of this routine.

  By controlling the air pressure of each tire in this way, as shown in FIG. 5A, the tire air pressure Pfl of the left front tire FL and the tire air pressure Prl of the left rear tire RL are respectively reduced, and the right front tire FR. The tire pressure Pfr and the tire pressure Prr of the right rear tire RR are increased. Therefore, the ratio of the right tire pressure to the left tire pressure is higher than the ratio of the tire pressure before the control.

  As a result, the ratio of the rolling resistance of the right tire to the rolling resistance of the left tire decreases. Further, the ratio of the dynamic load radius of the right tire to the dynamic load radius of the left tire increases. As described above, the right tire generates a force that causes the right side of the vehicle to be directed forward relative to the left side, and / or the left tire causes the left side of the vehicle to be directed rearward relative to the right side. Force is generated. As a result, since a counterclockwise (leftward) rotational moment M is generated around the center of gravity of the vehicle, the rightward deflection of the vehicle described above disappears.

(3) When leftward deflection occurs in the vehicle In this case, the deflection state value Dave is a negative value. Therefore, when the CPU 31 proceeds to step 415 in FIG. 4, it determines “No” in step 415, and also determines “No” in the subsequent step 430 and proceeds to step 440. Then, in step 440, the CPU 31 updates the target tire pressure Pfl of the left front tire FL by adding the change amount f (| Dave |) to the target tire pressure Pfl of the left front tire FL. Similarly, the target tire pressure Prl of the left rear tire RL is updated by adding the change amount f (| Dave |) to the target tire pressure Prl of the left rear tire RL.

  Further, the CPU 31 subtracts the change amount f (| Dave |) from the target tire air pressure Pfr of the right front tire FR and the target tire air pressure Prr of the right rear tire RR, respectively, so that the target tire air pressure Pfr and the right rear tire of the right front tire FR are subtracted. The target tire pressure Prr of the tire RR is updated. Then, the CPU 31 sends an instruction signal to the solenoid valve 21fl, the solenoid valve 21fr, the solenoid valve 21rl, and the solenoid valve 21rr so that the air pressure of each tire becomes the updated target tire pressure Pfl, Prl, Pfr, and Prr. send. Thereafter, the CPU 31 proceeds to step 495 via step 420, and once ends the processing of this routine.

  Accordingly, as shown in FIG. 5B, the ratio of the right tire pressure to the left tire pressure is lower than the ratio of the tire pressure before the control. Accordingly, the left tire generates a force that causes the left side of the vehicle to be directed forward relative to the right side, and / or the right tire causes the right side of the vehicle to be directed rearward relative to the left side. Will occur. As a result, since a clockwise (rightward) rotational moment M is generated around the center of gravity of the vehicle, the aforementioned leftward deflection of the vehicle disappears.

  As described above, the tire air pressure control device changes the ratio of the air pressure of the left tire and the air pressure of the right tire according to the deflection direction of the vehicle, so that the vehicle A rotational moment M is generated in a direction that eliminates the deflection state. As a result, the deflection of the vehicle can be eliminated without causing a steering off center.

  In addition, the tire air pressure control device is not a data D (n) that is an individual value indicating the deflection state of the vehicle, but a value obtained by averaging a plurality of data D (n) in terms of time (temporal average value). The tire pressure is controlled based on a certain deflection state value Dave. Thereby, compared with the case where the tire air pressure is changed every time the difference between the target yaw rate and the actual yaw rate is obtained, the deflection of the vehicle can be eliminated without destabilizing the behavior of the vehicle.

Note that step 205 to step 230 in FIG. 2 and step 410 in FIG. 4 estimate the target yaw rate γ ₀ from the vehicle speed V and the steering angle θ, and based on the estimated target yaw rate γ ₀ and the actual yaw rate γ, The difference data D (n) is obtained, and the difference between the plurality of target yaw rates and the actual yaw rate obtained every predetermined time in this way (data D (1), data D (2),... This corresponds to deflection state value acquisition means for obtaining the deflection state value Dave from the data D (n)). Further, step 415 and step 430 correspond to deflection direction estimating means for estimating the deflection direction of the vehicle based on the obtained deflection state value Dave.

  Further, step 435 and step 440 are instructions signals to the tire pressure changing device 21 so that a rotational moment in the direction of extinguishing the deflection state of the vehicle represented by the obtained deflection state value Dave is generated in the vehicle. Corresponds to control means for sending In other words, step 435 and step 440 change the center of gravity of the vehicle by changing the ratio of the air pressure of the left tire and the right tire according to the vehicle deflection direction estimated by the deflection direction estimating means. This corresponds to a control means for controlling the tire pressure changing device 21 so as to generate a rotational moment M in a direction in which the deflection of the vehicle disappears around.

  The present invention is not limited to the above embodiment, and various modifications can be employed within the scope of the present invention. For example, the tire air pressure control device 20 does not control the air pressure of all tires according to the deflection state value Dave, but selects an arbitrary tire from the left and right tires and changes the air pressure of the selected arbitrary tire. By doing so, the tire air pressure changing device 21 may be controlled so as to generate a rotational moment M in a direction in which the deflection of the vehicle disappears. Hereinafter, a case where the vehicle is deflected in the right direction will be described as an example.

  The tire air pressure control device 20 may select the right front tire FR and the right rear tire RR, and may control the tire air pressure changing device 21 to increase the air pressure (air pressure Pfr and air pressure Prr) of these tires. Alternatively, the tire pressure control device 20 may select only the right front tire FR or only the right rear tire RR and increase the air pressure of the selected tire.

  Further, the tire pressure control device 20 may select the left front tire FL and the left rear tire RL, and reduce the air pressure (air pressure Pfl and air pressure Prl) of these tires, or only the left front tire FL or the left rear tire. Only the tire RL may be selected, and the air pressure of the selected tire may be lowered.

  Further, the tire pressure control device 20 may select the right front tire FR and the left rear tire RL to increase the air pressure Pfr of the right front tire FR and decrease the air pressure Prl of the left rear tire RL. The right rear tire RR may be selected to lower the air pressure Pfl of the left front tire FL and increase the air pressure Prr of the right rear tire RR.

  The tire air pressure control device 20 includes an air pressure sensor that is attached to each tire and detects an actual air pressure of each tire, and the air pressure detected by the air pressure sensor coincides with the target tire air pressure of each tire described above. In addition, the tire pressure changing device may be controlled (feedback control). In addition, in step 435 and step 440 in FIG. 4, the target tire pressure of each tire is changed by a value based on the function f, but the target tire pressure of each tire is all set to a constant value or It can also be configured to change only a certain value individually determined for the tire. Further, the function f in step 435 and step 440 may be a function that is different for each tire.

  Further, the tire pressure control device 20 may obtain the deflection state value of the vehicle based on the actual yaw rate value when the steering angle θ of the steering wheel 10 is “0”. In addition, the tire pressure control device 20 is used in combination with a device that suppresses sudden automatic turning of the vehicle, such as a conventional device that controls the tire turning angle and a device that independently controls the braking force of each wheel. You can also.

It is a conceptual diagram of a vehicle equipped with a tire pressure control device and a tire pressure control device. It is the flowchart which showed the program which CPU shown in FIG. 1 performs in order to acquire and calculate the deflection state value of a vehicle. It is the figure which showed the deflection state value Dave which is the data D (n) which shows the deflection state of the vehicle estimated from the target yaw rate and the actual yaw rate, and its average value. It is the flowchart which showed the program which CPU shown in FIG. 1 performs in order to control the air pressure of each tire. FIG. 5A is a conceptual diagram showing a state in which the tire air pressure is controlled in order to generate a counterclockwise rotation moment, and FIG. 5B is a tire pressure in order to generate a clockwise rotation moment. It is the conceptual diagram which showed the state which controlled.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Steering wheel, 20 ... Tire pressure control device, 21 ... Tire pressure change device, 21a ... Pump, 21b ... Accumulator, 21fl, 21fr, 21rl, 21rr ... Solenoid valve, 30 ... Electric control device, 31 ... CPU, 40 ... Vehicle speed sensor, 41 ... steering angle sensor, 42 ... yaw rate sensor.

Claims (3)

A tire pressure changing device for changing at least one of the plurality of tires provided in the vehicle according to the instruction signal;
Driving state detecting means for detecting the driving state of the vehicle;
Deflection state value acquisition means for acquiring a deflection state value which is a value representing the deflection state of the vehicle based on the detected driving state;
Control means for sending the instruction signal to the tire air pressure changing device so that a rotational moment in a direction for eliminating the deflection state of the vehicle represented by the acquired deflection state value is generated in the vehicle;
Tire pressure control device equipped with. In the tire pressure control device according to claim 1,
The operating state detecting means is
Vehicle speed detecting means for detecting the speed of the vehicle;
A steering angle sensor for detecting a steering angle of a steering wheel of the vehicle;
A yaw rate sensor that detects an actual yaw rate that is the yaw rate of the vehicle;
With
The deflection state value acquisition means includes
Based on the detected vehicle speed and the detected steering angle, a target yaw rate that is an ideal yaw rate to be generated in the vehicle when a factor for deflecting the vehicle is not generated is estimated, and the estimation is performed. A tire pressure control device configured to acquire the deflection state value based on a difference between the target yaw rate that has been set and the actual yaw rate detected by the yaw rate sensor. In the tire pressure control device according to claim 2,
The deflection state value acquisition means includes
The difference between the target yaw rate and the actual yaw rate is obtained every elapse of a predetermined time, and the difference between the target yaw rate and the actual yaw rate obtained every elapse of the predetermined time is averaged over a period longer than the predetermined time. A tire pressure control device configured to acquire the deflection state value based on an averaged value.

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