JP4876594B2 - Seat cushion stiffness adjustment device - Google Patents

Description

  The present invention relates to a seat cushion stiffness adjusting device that adjusts the cushion stiffness of a vehicle seat.

2. Description of the Related Art Conventionally, an occupant posture control apparatus that performs occupant posture control in accordance with the traveling environment of a vehicle is known (see, for example, Patent Document 1). This occupant posture control device controls the seat cushion pressure to be hardened by increasing the seat cushion pressure when there are many curves in the traveling direction of the vehicle or when it is predicted that the number will increase. By controlling in this way, the physical burden on the driver due to the curve is reduced.
JP 2005-119559 A

  By the way, veteran drivers such as test drivers with advanced driving skills, when grasping the behavior of the vehicle, the more the vehicle's behavior approaches an unstable state, the more emphasis is placed on the information felt by the body than the information obtained from the vision Tend. Therefore, in order to bring the driving skill of a general driver closer to the driving skill of a veteran driver who is good at feeling the behavior of the vehicle with the body, the behavior of the vehicle is as much as possible to the driver's body as the behavior of the vehicle becomes unstable. It is desirable to make it easy to feel.

  In this regard, if the seat is hardened as in the above-described prior art, the behavior of the vehicle can be easily felt by the body to the driver. However, in the above-described conventional technology, since the seat does not become hard unless the vehicle is traveling on a curve, the driver can easily feel the behavior of the vehicle on the body except when the vehicle is traveling on a curve. There wasn't.

  Accordingly, an object of the present invention is to provide a seat cushion stiffness adjusting device that facilitates transmission of vehicle behavior to a driver's body.

In order to solve the above problems, as the present invention,
Detecting means for detecting the behavior state of the vehicle;
Determination means for determining the behavior of the vehicle based on the behavior state detected by the detection means;
A stiffness variable means for varying the stiffness of the vehicle seat cushion,
The rigidity changing means increases the rigidity of the seat cushion when the behavior of the vehicle is determined to fall into an unstable or unstable state by said determining means, you lower the rigidity of the seat cushion when the vehicle is stopped A seat cushion rigidity adjusting device is provided.
In order to solve the above problems, the present invention
Detecting means for detecting the behavior state of the vehicle;
Determination means for determining the behavior of the vehicle based on the behavior state detected by the detection means;
A stiffness variable means for varying the stiffness of the vehicle seat cushion,
The rigidity variable means increases the rigidity of the seat cushion when the determination means determines that the vehicle behavior is unstable or unstable, and the determination means determines that the vehicle behavior is stable Further, the present invention provides a seat cushion stiffness adjusting device characterized by lowering the stiffness of the seat cushion.
In order to solve the above problems, the present invention
Detecting means for detecting the behavior state of the vehicle;
Determination means for determining the behavior of the vehicle based on the behavior state detected by the detection means;
A stiffness variable means for varying the stiffness of the vehicle seat cushion,
The rigidity variable means increases the rigidity of the seat cushion at the seat side than the rigidity of the seat cushion at the center of the seat when the determination means determines that the behavior of the vehicle is unstable or unstable. A seat cushion stiffness adjusting device is provided.

  In the present invention, the detection means detects a vehicle body slip angle as a vehicle behavior state, and the determination means determines that the vehicle behavior is unstable when the vehicle body slip angle exceeds a predetermined value. It is preferable.

  In the present invention, it is preferable that the rigidity varying means increases the rigidity of the seat cushion on the side of the seat.

  In the present invention, it is preferable that the stiffness varying means varies the pressure of the seat cushion.

  According to the present invention, the behavior of the vehicle can be easily transmitted to the driver's body.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a seat cushion rigidity adjusting apparatus according to the present invention. The seat cushion stiffness adjusting device of this embodiment includes an acceleration sensor 1, a yaw rate sensor 2, a vehicle speed sensor 3, an electronic control unit 10 (hereinafter referred to as ECU 10), and a seat cushion stiffness variable mechanism 20. The ECU 10 grasps the behavior of the vehicle based on information from the acceleration sensor 1, the vehicle speed sensor 2, and the yaw rate sensor 3, and controls the seat cushion stiffness varying mechanism 20 so as to vary the stiffness of the seat cushion according to the behavior of the vehicle. To do. Specifically, the ECU 10 determines a state in which the behavior of the vehicle is unstable based on the behavior state of the vehicle detected by the acceleration sensor 1, the yaw rate sensor 2, and the vehicle speed sensor 3, and determines that the state is unstable. In this case, the seat cushion stiffness variable mechanism 20 is controlled so as to increase the stiffness of the seat cushion.

  Here, a state where the behavior of the vehicle is unstable will be described with reference to FIG. FIG. 2 is a diagram illustrating the behavior of a vehicle driven by a veteran driver (that is, a driver having a high driving skill) when a double lane change is performed. In FIG. 2, the horizontal axis represents the travel distance X, the left vertical axis represents the steering angle θ by the driver, and the right vertical axis represents the vehicle body slip angle β. P * represents a pylon (cone), and the arrangement of the pylon P is schematically shown in FIG. That is, FIG. 2 shows changes in the steering angle θ of the steering wheel steered by the driver and the vehicle body slip angle β with respect to the travel distance X when a double lane change is performed.

  It is assumed that the vehicle travels from the left side to the right side in FIG. The double lane change means that the vehicle travels along the pylon P arranged as shown in FIG. The double lane change course schematically shown in FIG. 2 includes a first pylon group composed of P1 to P10 pylons arranged up to about 20 m and a P11 to P17 pylon arranged up to about 40 m to 70 m. And a third pylon group composed of P18-P27 pylons arranged in the vicinity of 70 m to 90 m. The vehicle travels straight along the first pylon group, and then passes between pylons P11 and P17 of the second pylon group arranged offset to the left side (upper side in FIG. 2) and is regarded as a wall. In order not to collide with the pylons P11 to P16 of the pylon group, it is necessary to pass between the pylons P18 and P23 of the third pylon group arranged offset to the right side (lower side in FIG. 2). As a result, it is possible to simulate the same situation as when a double lane change is performed in which steering steering is repeated twice in succession.

  The steering angle θ of the steering shown in FIG. 2 is positive when steering from the neutral position to the right (downward steering in FIG. 2), and steering from the neutral position to the left (upper FIG. 2). Steering to the upper side) is negative.

  Further, the vehicle body slip angle β shown in FIG. 2 is also called a side slip angle, and as shown in FIG. 4, it is an angle formed by the direction of the vehicle body and the traveling direction of the vehicle center of gravity. The vehicle has a characteristic that the vehicle body slip angle β increases as the cornering speed increases. As the vehicle body slip angle β increases, the degree of instability in the behavior of the vehicle increases. When the vehicle body slip angle β exceeds a certain value, the vehicle falls into a steering impossible state such as spin. The vehicle body slip angle β that falls into the uncontrollable state varies depending on the surrounding environment such as the vehicle type and the road surface condition.

  When a vehicle body slip angle β exceeds 10 °, a certain vehicle is in a state in which the behavior of the vehicle becomes unstable and the vehicle cannot easily be steered (a region above the dotted line shown in FIG. 2). In FIG. 2, the peak of the vehicle body slip angle β and the steering steering angle θ overlap each other around 55 m where the vehicle body slip angle β exceeds 10 °. Even if the vehicle body slip angle β exceeds 10 °, the steering that the veteran driver steered to the left is returned to the right as the vehicle body slip angle β decreases (the vehicle returns to the stable direction). It shows that. Furthermore, since the phase change between the vehicle body slip angle β and the steering angle θ is almost the same in subsequent driving, it is shown that the veteran driver can steer the steering skillfully according to the slip state of the vehicle. ing. That is, it is shown that the steering can be performed so that the vehicle body slip angle β is reduced and the behavior of the vehicle is directed to a stable state.

  However, in a general driver who is not an experienced driver, when the vehicle body slip angle β exceeds 10 °, skillful steering cannot be performed as shown in FIG. 2, and the vehicle body slip angle β and the steering angle θ The waveform does not correspond to the phase change. This is because ordinary drivers tend to steer and depend on information obtained from the visual sense even when such a vehicle is unstable. This is because they are not good at feeling. In order to make it easier for a general driver to feel the behavior of the vehicle with the body, the seat cushion should be harder than usual. However, in general, vehicle seat cushions are softened to make it difficult to feel the vibration and behavior of the vehicle. If the seat cushions are hardened in advance, the usual comfort when seated on the seat is impaired. It will be.

  Therefore, the seat cushion rigidity adjusting device of the present embodiment controls to increase the rigidity of the seat cushion when the behavior of the vehicle is unstable or when it is likely to fall into an unstable state. The configuration of the seat cushion rigidity adjusting device of the present embodiment will be described with reference to FIG.

  The acceleration sensor 1 detects the acceleration (lateral G) of the own vehicle in the vehicle width direction. A signal representing the acceleration (so-called lateral G) in the vehicle width direction of the host vehicle is output to the ECU 10. Therefore, the ECU 10 can calculate the lateral G of the host vehicle based on the signal output from the acceleration sensor 1.

  The vehicle speed sensor 2 detects the vehicle speed of the host vehicle. A signal representing the speed of the host vehicle is output to the ECU 10. Therefore, the ECU 10 can calculate the vehicle speed of the host vehicle based on the signal output from the vehicle speed sensor 5. If a signal indicating that the vehicle speed is zero is input, the ECU 10 can recognize that the vehicle is stopped.

  The yaw rate sensor 3 is rotation detection means that detects rotation of the vehicle in the yaw direction. The yaw rate sensor 3 is mounted on the vehicle and detects an angular velocity (yaw rate) around the center of gravity of the vehicle generated by the yaw motion. According to the yaw rate sensor 3, it is possible to detect that the running vehicle is making a yaw motion by steering or the like. A signal representing the angular velocity detected by the yaw rate sensor 3 is output to the ECU 10. Therefore, the ECU 10 can calculate the angular velocity (yaw rate) around the center of gravity of the host vehicle based on the signal output from the yaw rate sensor 1.

  Further, the rotation detecting means for detecting the rotation of the vehicle in the yaw direction may be a gyro sensor instead of the yaw rate sensor 1. The gyro sensor detects an angle of three axes of X (roll), Y (pitch), and Z (yaw), an angular velocity, an acceleration, and the like. Therefore, in the case of a gyro sensor, the rotation in the yaw direction of the vehicle can be detected by using the detection value for the Z axis.

The ECU 10 grasps the behavior state of the vehicle based on the signals from the acceleration sensor 1, the vehicle speed sensor 2, and the yaw rate sensor 3, and calculates the vehicle body slip angle β as data representing the behavior state of the vehicle. The vehicle body slip angle β is, for example,
[Equation 1]
β = ∫ {(lateral G-yaw rate × vehicle speed) / vehicle speed} dt
It is possible to calculate by.

  The ECU 10 determines a state in which the behavior of the vehicle is unstable based on the vehicle body slip angle β calculated according to [Equation 1]. For example, the ECU 10 sets the threshold value of the vehicle body slip angle β for determining the state where the vehicle behavior is unstable to 10 °, and the vehicle behavior when the calculated vehicle body slip angle β exceeds 10 °. Is determined to be unstable. The ECU 10 that has determined that the behavior of the vehicle is unstable outputs a command to the seat cushion stiffness varying mechanism 20 to increase the seat cushion stiffness to a predetermined value.

  Further, the ECU 10 can also determine a state where the behavior of the vehicle is stable based on the vehicle body slip angle β calculated according to [Equation 1]. For example, the ECU 10 sets the threshold value of the vehicle body slip angle β for determining a state in which the vehicle behavior is stable to 5 °, and the vehicle behavior is changed when the calculated vehicle body slip angle β is less than 5 °. It is determined that the state is stable. The ECU 10 that has determined that the behavior of the vehicle is stable outputs a command to the seat cushion stiffness varying mechanism 20 to lower the seat cushion stiffness to a predetermined value.

  Therefore, the ECU 10 determines a command content to be output to the seat cushion stiffness varying mechanism 20 according to a threshold relationship as shown in FIG. 3, for example. That is, the ECU 10 outputs a command to increase the stiffness of the seat cushion to a predetermined value when the vehicle body slip angle β exceeds 10 ° when the stiffness of the seat cushion is low, and the vehicle body slip when the stiffness of the seat cushion is high. When the angle β is less than 5 °, a command for lowering the rigidity of the seat cushion to a predetermined value is output.

  In addition, by setting the threshold value of the vehicle body slip angle β that increases the rigidity of the seat cushion to a predetermined value, the rigidity of the seat cushion can be increased in a state where the behavior of the vehicle is actually unstable. Yes, by setting a lower threshold for the vehicle body slip angle β that increases the seat cushion rigidity to a predetermined value, the seat cushion rigidity is increased before the vehicle behavior becomes unstable. be able to.

  The ECU 10 includes a plurality of ROMs such as a ROM for storing control programs and control data, a RAM for temporarily storing control program processing data, a CPU for processing control programs, and an input / output interface for exchanging information with the outside. It is composed of circuit elements. The ECU 10 is not limited to one electronic control unit, and may be a plurality of control units so that control is shared.

  The seat cushion stiffness varying mechanism 20 shown in FIG. 1 is means for varying the stiffness of the seat cushion as shown in FIG. 5 based on a command signal from the ECU 10. The seat cushion stiffness varying mechanism 20 varies, for example, the spring constant of a spring built in the seat cushion, varies the resilience coefficient of the seat cushion, or varies the pressure in the seat cushion with an accumulator or the like. As a result, the rigidity of the seat cushion is varied.

  FIG. 5 is a schematic diagram of the entire sheet. The seat cushion shown in FIG. 5 includes a pillow portion 30 that supports the head of the occupant, a backrest portion 40 that supports the upper half of the occupant, and a seating portion 50 that supports the lower half of the occupant. Moreover, the pillow part 30 has a cushion part comprised from the side parts 31 and 32 and the center part 33, and the backrest part 40 has a cushion part comprised from the side parts 41 and 42 and the center part 43, and a seating part. 50 has a cushion part composed of side parts 51, 52 and a central part 53. The side portions 31, 32, 41, 42, 51, 52 improve the supportability of the occupant seated on the seat.

  FIG. 6 is a diagram illustrating an example of a seat cushion stiffness varying mechanism 20 that varies the pressure in the seat cushion illustrated in FIG. 5 by the accumulator 21. As shown in FIG. 6, the side parts 31, 32 and the central part 33 of the pillow part 30, the side parts 41, 42 and the central part 43 of the backrest part 40, and the side parts 51, 52 and the central part 53 of the seating part 50. A pressurizing unit (a portion where a, b, and c of 31a and the like are attached to the reference numerals) to which a medium such as a fluid is supplied by the accumulator 21 is installed. The rigidity of each cushion part changes by changing the pressure value of a pressurizing part. For example, increasing the pressure value of the pressurizing part 31a increases the rigidity of the side part 31 of the pillow part 30, and increasing the pressure value of the pressurizing part 43b increases the rigidity of the central part 43 of the backrest part 40. The pressure value of each pressurizing unit may be changed uniformly or may be changed differently.

  The seat cushion stiffness varying mechanism 20 shown in FIG. 6 varies the pressure value of each pressurizing unit based on a command signal from the ECU 10. For example, when the ECU 10 that has determined that the behavior of the vehicle is unstable outputs a command to increase the stiffness of each cushion part (pressure value of each pressurizing unit) to a predetermined value, the seat cushion stiffness variable mechanism 20 according to the output command. Increases the pressure value of each pressurizing part. When the ECU 10 that has determined that the behavior of the vehicle is stable outputs a command to lower the stiffness of each cushion part (pressure value of each pressurizing unit) to a predetermined value, the seat cushion stiffness varying mechanism 20 Reduce the pressure value in the pressurizing section.

  Further, the rigidity of only a part of the cushion parts may be changed instead of changing the rigidity of all the cushion parts uniformly. For example, only the side portions 31, 32, 41, 42, 51, 52 of the cushion part are varied. The ECU 10 that has determined that the behavior of the vehicle is unstable causes the rigidity of the side portions 31, 32, 41, 42, 51, and 52 to be a predetermined value (for example, a value that is higher than the respective central portions 33, 43, and 53). In response to the output command, the seat cushion stiffness varying mechanism 20 causes the pressure values of the pressurizing portions installed in the side portions 31, 32, 41, 42, 51, 52 to be changed to the central portions 33, 43, The pressure value of the pressurizing unit installed at 53 is set higher. On the other hand, when the pressure value is lowered, the ECU 10 that has determined that the behavior of the vehicle is stable sets the rigidity of the side portions 31, 32, 41, 42, 51, and 52 to a predetermined value (for example, normal rigidity). In response to the output command, the seat cushion stiffness varying mechanism 20 outputs the pressure value of the pressurizing portion installed in the side portions 31, 32, 41, 42, 51, 52 to the normal value. make low.

  The present invention does not specify the mechanism for changing the rigidity of the seat cushion in detail, and can be applied to a seat cushion rigidity changing mechanism having any configuration or characteristic. Detailed description of the obvious seat cushion stiffness variable mechanism is omitted.

  Therefore, according to the seat cushion stiffness adjusting apparatus of the present embodiment, the seat cushion stiffness is increased more than usual in an abnormal situation such as when the behavior of the vehicle is unstable or when it is likely to fall into an unstable state. This makes it easier for the driver to feel the vehicle's behavior than usual. As a result, even a general driver can easily feel the behavior of the vehicle in such an abnormality, so that it is possible to perform a driving operation that makes the behavior of the vehicle a stable direction. On the other hand, since the cushion rigidity of the seat is low at normal times, comfort during riding during normal times can be maintained.

  Further, according to the seat cushion stiffness adjusting apparatus of the present embodiment, the behavior of the vehicle is determined based on the vehicle body slip angle β, so that the vehicle behavior is more accurately compared to the case where the behavior of the vehicle is determined based on the yaw rate. A state where the behavior is unstable can be determined. This is because even if the value of the yaw rate is large, the behavior of the vehicle is not always unstable.

  Further, according to the seat cushion rigidity adjusting apparatus of the present embodiment, the rigidity of a part of the seat cushion can be changed, not the rigidity of the entire seat cushion. Increasing the rigidity of the cushion on the side of the seat not only makes it easier for the occupant to grasp the behavior of the vehicle, but also improves the supportability of the occupant and increases safety.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, the present invention is not limited to changing the cushion rigidity of a front seat such as a driver seat or a passenger seat, but may be a case of changing the cushion rigidity of a rear seat.

  Moreover, the cushion stiffness of the seat may be further subdivided instead of the two steps of high and low. For example, by providing a plurality of pressure values of the pressurizing portion that can be set by the seat cushion stiffness varying mechanism 20, the cushion stiffness can be variously changed.

  Further, instead of lowering the seat cushion rigidity when the vehicle body slip angle β falls below a predetermined value as in the above-described embodiment, the seat cushion rigidity is lowered when it is detected that the vehicle has stopped. May be. For example, if the ECU 10 detects that the vehicle has stopped when the vehicle speed sensor 2 detects the vehicle speed zero, the shift position sensor detects the parking "P" state, or detects that the ignition key is turned off, Good.

1 is a block diagram illustrating an embodiment of a seat cushion rigidity adjusting device according to the present invention. It is a figure which shows the behavior of the vehicle when the vehicle which a veteran driver drives has performed the double lane change. It is a figure which shows the threshold value relationship of the vehicle body slip angle (beta) which makes the rigidity of a seat cushion variable. It is a figure for demonstrating the vehicle body slip angle (beta). It is one schematic diagram of the whole sheet | seat. It is a figure which shows an example of the seat cushion rigidity variable mechanism 20 which varies the pressure in the seat cushion shown by FIG.

Explanation of symbols

1 Acceleration sensor 2 Vehicle speed sensor 3 Yaw rate sensor 10 ECU
20 Seat cushion stiffness variable mechanism 21 Accumulator 30 Pillow part 40 Backrest part 50 Seating part

Claims (6)

Detecting means for detecting the behavior state of the vehicle;
Determination means for determining the behavior of the vehicle based on the behavior state detected by the detection means;
A stiffness variable means for varying the stiffness of the vehicle seat cushion,
The rigidity changing means increases the rigidity of the seat cushion when the behavior of the vehicle is determined to fall into an unstable or unstable state by said determining means, you lower the rigidity of the seat cushion when the vehicle is stopped A seat cushion rigidity adjusting device characterized by the above. Detecting means for detecting the behavior state of the vehicle;
Determination means for determining the behavior of the vehicle based on the behavior state detected by the detection means;
A stiffness variable means for varying the stiffness of the vehicle seat cushion,
The rigidity variable means increases the rigidity of the seat cushion when the determination means determines that the vehicle behavior is unstable or unstable , and the determination means determines that the vehicle behavior is stable and wherein to Rukoto low rigidity of the seat cushion, the rigidity adjusting device for a seat cushion. Detecting means for detecting the behavior state of the vehicle;
Determination means for determining the behavior of the vehicle based on the behavior state detected by the detection means;
A stiffness variable means for varying the stiffness of the vehicle seat cushion,
The rigidity variable means increases the rigidity of the seat cushion at the seat side than the rigidity of the seat cushion at the center of the seat when the determination means determines that the behavior of the vehicle is unstable or unstable. A seat cushion rigidity adjusting device characterized by the above. The detection means detects a vehicle body slip angle as a behavior state of the vehicle,
The seat cushion rigidity adjusting apparatus according to any one of claims 1 to 3, wherein the determination unit determines that the behavior of the vehicle is unstable when the vehicle body slip angle exceeds a predetermined value. The seat cushion rigidity adjusting device according to claim 1, wherein the seat cushion is a seat cushion on a side portion of the seat. The seat cushion stiffness adjusting apparatus according to any one of claims 1 to 3, wherein the stiffness varying means varies the pressure of the seat cushion.

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