JPH0446814A - Height adjustment device - Google Patents

Abstract

PURPOSE:To alleviate a shock to a pedestrian at the time of the collision of a vehicle with him/her by making judgement about the possibility of the collision on the basis of vehicle travel information and pedestrian walking information, when the pedestrian is detected forward in the travel direction of the vehicle, and lowering the height of the vehicle via the contraction of a suspension device at the side of the collision, when there is such a possibility. CONSTITUTION:When a pedestrian is detected forward in the travel direction of a vehicle via an infrared radar 11, information related thereto is inputted to a judgement control section 8. This judgement control section 8 calculates a distance from the vehicle to the pedestrian, and an approaching speed of the vehicle and pedestrian, or the relative speed thereof on the basis of a measurement result via the infrared radar 11. According to the result of the calculation, judgement is made about the possibility of the collision of the vehicle with the pedestrian. If the judgement indicates that there is a possibility of collision, a signal of time up to the collision is sent to a height control section 7, and the height of the vehicle at the collision side thereof, or the height at the side of front wheels is lowered for generating a nose dive phenomenon, thereby alleviating the shook of the collision.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a vehicle in which each of the front and rear wheels of a vehicle is supported by a suspension, and the attitude of the vehicle is maintained constant by controlling the suspension. Related to improvement of vehicle height adjustment device.

[Conventional technology]

As a conventional vehicle height adjustment device, there is one shown in FIG. 6, for example. This is front wheel 1. As a suspension mechanism for the rear wheel 2, a damper and a spring are held by hydraulic actuators 3 and 4, and the hydraulic pressure of the actuator 3 is controlled using the controller 5 of the front wheel 1 system, and the hydraulic pressure of the actuator 3 is controlled using the controller 6 of the rear wheel 2 system. By adjusting the hydraulic pressure of the actuator 4, the strength of the spring of each wheel 1, 2 as well as the actuator of each wheel 1.2 is expanded or contracted. The controllers 5 and 6 adjust the oil pressure supplied to each wheel based on instructions from the control section 13. This control unit 13 includes several G sensors (acceleration sensors).
9 and a vehicle height sensor 10 are connected, and acceleration/deceleration data and vehicle height data acting on the vehicle measured by these sensors are supplied one by one. The optimum vehicle height is calculated based on these data, and from this result the controller 5,
6, an oil pressure instruction is given. Based on these instructions, the controllers 5 and 6 actuate the actuators 3 and 4 of each wheel 1 and 2.
The actuators of each wheel 1.2 expand and contract to suppress vibrations so that the vehicle maintains a constant posture.

In this vehicle height adjustment device, the vehicle posture is controlled to maintain a constant vehicle posture as much as possible no matter what kind of road environment or driving environment.

For example, when a vehicle is braking, a so-called nose dive phenomenon occurs in which the front end of the vehicle sinks. At that time, this vehicle height adjustment device maintains the vehicle height by increasing hydraulic pressure to the front wheel actuator 3. It operates to prevent the pitching phenomenon of the vehicle. Alternatively, if there is a joint or uneven surface on the road, the G sensor 9 is used to detect the road surface condition, and the actuator 3 of each wheel 1.2 is activated to prevent the vehicle from pitching or rolling each time. 4, the actuators of each wheel 1.2 instantaneously expand and contract to suppress vibrations so that the vehicle maintains a very constant posture.

Next, the processing flow of this operation is shown in FIG.

First, the control unit 13 measures the acceleration of the vehicle in the vertical direction, left and right directions (step 551), and calculates the length of the actuator for each wheel based on this information (step 552).
After L/, the basic value of the hydraulic pressure to be sent to the actuators 3, 4 of each wheel 1, 2 in order to keep the vehicle attitude constant is calculated (step 553). A hydraulic pressure correction calculation is performed according to the acceleration state and braking state of the vehicle (step 554), and information on the finally determined hydraulic pressure value is sent to the front and rear vehicle controllers 5 and 6 (step 555). Each controller 5.6 supplies hydraulic pressure to each actuator 3, 4 of the front wheel 1 and rear wheel 2, respectively, to maintain a constant vehicle posture.

[Problem to be solved by the invention]

By the way, with the conventional vehicle height adjustment device as described above, even if the vehicle collides with a pedestrian while the brakes are applied, the vehicle is adjusted to maintain a constant posture.
The front of the vehicle could remain at normal height.

Therefore, a technical problem of the present invention is to forcibly generate a nose dive phenomenon when a collision with a pedestrian is unavoidable, thereby minimizing the impact value on the pedestrian.

[Means to solve the problem]

In order to solve the above-mentioned technical problems, the present invention provides a vehicle height adjustment device in which each of the front and rear wheels of a vehicle is held by a suspension, and the suspension is expanded and contracted to maintain a constant posture of the vehicle. a detection means for detecting a pedestrian when a pedestrian appears in the traveling direction of the vehicle;
A determining means for determining whether or not a collision with a pedestrian will occur based on the detection information obtained from the detecting means and driving information of a vehicle approaching the pedestrian, and based on the determination result of the determining means that there is a possibility of a collision. This method incorporates a vehicle height lowering means that reduces the suspension and lowers the vehicle height on the collision side immediately before a collision.

[Effect]

According to the above-mentioned means, when a pedestrian appears in the traveling direction of the vehicle while the vehicle is traveling, the pedestrian is detected by the detection means provided in the vehicle. Then, the determining means determines the possibility of a collision with the pedestrian based on this detection information and the traveling information of the vehicle approaching the pedestrian.

If the determining means determines that a collision between the vehicle and a pedestrian is unavoidable, the vehicle height lowering means compresses the suspension on the collision side of the vehicle to lower the vehicle height.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a block diagram showing an example of the present invention. As explained in the conventional example, the suspension of each wheel 1, 2 is held by hydraulic actuators 3, 4, and each actuator 3, 4 is controlled using controllers 5, 6 for front wheel 1 system and rear wheel 2 system. hydraulic pressure is regulated. These controllers 5 and 6 adjust the oil pressure supplied to the actuators 3 and 4 of each wheel 1 and 2 based on instructions from the vehicle height control section 7. Further, the vehicle height control section 7 is composed of a microcomputer, and several G sensors 9 and vehicle height sensors 10 are connected to this vehicle height control section 7, and based on data from these, each wheel 1, 2 The present embodiment further includes a determination control section 8, which expands and contracts the actuator to suppress vibrations so that the vehicle maintains a constant posture. This determination control section 8 is composed of a microcomputer similarly to the vehicle height control section 7 described above, and operates according to a control program written in a memory. A pair of infrared radars 11 that detect obstacles in front of the vehicle and a contact sensor 12 embedded in the bumper surface are connected to the determination control unit 8, and based on the detection information from these, it detects obstacles in front of the vehicle. to determine the possibility of a collision with the vehicle. and vehicle height control section 7
and the determination control section 8 are connected to each other so that information can be exchanged.

Next, the operation of the determination control section 8 will be explained based on the processing flow shown in FIG. In this judgment control unit 8, the infrared radar 11
The measurement results are taken in and predetermined processing is performed. First, based on the measurement results from the infrared radar 11, an obstacle in front of the vehicle is detected and its distance is measured (step 541). Furthermore, the speed at which the obstacle and the vehicle approach each other, that is, the relative speed v0 is calculated (step 542).
. By the way, the deceleration of the vehicle that allows the vehicle to stop most quickly is α. Then, the condition for determining the possibility of collision between the vehicle and the obstacle is expressed by equation 0 (step 543).

L>Vo ” Vo / 2 ” (Xo ”
” '■If this equation 0 is no longer satisfied, the possibility of a collision becomes extremely high. In that case, the distance M between the vehicle and the obstacle
L and the above-mentioned relative velocity V. Time to collision Δ based on
Calculate t using the formula (Step 544).

Δt=L/■o...■ Next, the temperature T of the obstacle is measured by the infrared sensor (step 545), and it is determined whether the obstacle is a pedestrian, another vehicle, or a fixed object.

At that time, the temperature is evaluated within a certain range (T1 <human body temperature T2) of a normal person (step 846). If it is determined that the obstacle is a pedestrian and a collision is unavoidable, an emergency signal is generated (Em=1) (step 547).

In other cases, it is determined that the situation is normal and an emergency signal is generated (E
m=0) (step 548). This emergency signal (E
m) and the information on the time Δt until collision are immediately sent to the vehicle height control section 7.

On the other hand, in addition to the determination control section 8, the vehicle height control section 7 sequentially performs the processing shown in the processing flow of FIG. First, the G sensor 9 determines the top, bottom, left and right of the vehicle.

The acceleration acting in the longitudinal direction is measured (step 521).

Next, after calculating the length of the actuator for each wheel 1.2 based on this information (step 522), the length of the actuator for each wheel 1.2 is calculated in order to maintain a constant vehicle posture.
, 4 (step 523). Next, it is determined whether or not there is an emergency signal (E m ) sent from the determination control section 8 (step 524). Here, if there is no emergency signal (Em=O), the front of the vehicle is normal, so normal processing is performed, and hydraulic pressure correction calculation is performed according to the acceleration state and brake condition of the vehicle (step 525), and the final Information on the hydraulic pressure value thus determined is sent to each controller 5.6 (step 826). On the other hand, when there is an emergency signal (Em = 1), a collision with a pedestrian is unavoidable, so the hydraulic pressure of the actuator 4 of the rear wheel 2 remains the same as before, and the hydraulic pressure of the actuator 3 of the front wheel 1 is Control is performed to lower the pressure and lower the vehicle height in front (step 527).

If the contact sensor 12 of the bumper detects contact, the nose dive phenomenon is continued while the front vehicle height is lowered (step 529). However, if the contact sensor 12 provided on the bumper does not detect a contact even though the time Δt calculated by the determination control unit 8 has elapsed, the emergency signal is not detected. (Step 530) This emergency signal is regarded as a malfunction.

Therefore, according to this embodiment, as shown in FIG. 4, when a collision with a pedestrian cannot be avoided, the normal function of the vehicle height adjustment mechanism is canceled and the height of the vehicle in front is forcibly lowered. Causes a dive phenomenon. In this case, the vehicle bumper 21 hits the pedestrian's lower part from the knee 31, and the acceleration of the thigh 32 or waist 33 in the forward direction of the vehicle decreases. Furthermore, since the waist portion 33 interferes with the hood edge portion 22 or the hood 23 from above, partly because the hood edge portion 22 is low, the impact received from the vehicle body can be reduced. Therefore, the jumping phenomenon of the pedestrian's body is suppressed, and the behavior of the pedestrian becomes pedestrian 44, pedestrian 45, and pedestrian 46 in order as shown in FIG. 4, and the head 34 of pedestrian 46 Only interference with the hood 23 is required, the impact is alleviated, and pedestrians are effectively protected.

In addition, when lowering the height of the vehicle in front immediately before the collision, the position of the vehicle bumper 21 is lowered below the height of the pedestrian's knees 31, as shown in FIG. It is best to operate the vehicle height adjustment device so that the relationship is expressed by the formula 0.

Hb<Hk-Wb/2...■ In this formula, wb indicates the width of the bumper in the upper and lower blade direction.

Furthermore, assuming that the pedestrian is Japanese,
It is appropriate to lower the height of the bumper by 50 to 100 m from the standard position.

Note that even if there is a collision with a pedestrian without the vehicle braking, the judgment control unit 8 determines whether or not there is a collision based on information on the relative speed between the vehicle and the pedestrian and the distance between the pedestrian and the pedestrian. A similar effect can be obtained by forcibly lowering the height of the vehicle in front of the vehicle and causing a nose dive phenomenon when there is a possibility of a collision.

Also, when accelerating the vehicle, the rear of the vehicle sinks,
The front will be in a raised position. Therefore, if you collide with a pedestrian in that condition, it will be a terrible disaster for the pedestrian.
At this time, the determination control unit 8 determines the presence or absence of a collision based on the information on the distance to the pedestrian and the acceleration of the vehicle, and when there is a possibility of a collision, the nose dive phenomenon is forcibly generated, so that the above-mentioned implementation can be carried out. The same effect as in the example can be obtained.

On the other hand, in the case of a collision with a pedestrian when the vehicle is running in reverse, the detection means is installed facing toward the rear of the vehicle body, and the above embodiment is applied to the control of the rear wheels to cause the rear of the vehicle body to sink. You can get the following effect.

In addition, pedestrians in the present invention include those riding two-wheeled vehicles such as bicycles, and even in the case of a collision between this person and a vehicle, the above embodiment can be applied to forcibly prevent the nose dive phenomenon. By generating it and applying it to the bottom of the wheel, the impact of a collision is alleviated.

〔effect〕

As explained above, according to the present invention, the detection means detects a pedestrian, and based on the determination result of the determination means, the vehicle height lowering means retracts the suspension immediately before the collision with the pedestrian, so that the vehicle on the collision side Since the height is made low, even in the event of a collision with a pedestrian, the impact value on the pedestrian can be reduced, which is effective for pedestrian protection.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a vehicle height adjustment device according to an embodiment of the present invention;
Fig. 2 is a processing flow of the determination control section, Fig. 3 is a processing flow of the vehicle height control section, Fig. 4 is an explanatory diagram at the time of a collision between a pedestrian and a vehicle according to this embodiment, and Fig. 5 is an illustration of this embodiment. FIG. 6 is a diagram illustrating the height of a bumper according to an example, FIG. 6 is a configuration diagram according to a conventional example, and FIG. 7 is a processing flow of a control section according to a conventional example. 1... Front wheel 2... Rear wheel 3.4... Actuator (suspension) 7...
・Vehicle height control section (vehicle height lowering means) 8... Judgment control section (judgment means) 11... Infrared radar (detection means) Special fraud applicant Nissan Motor Co., Ltd. Figure 3.4-77 Child 1 Eta Kazu Daiindaizu Flute Museum Map

Claims (3)

[Claims] (1) In a vehicle height adjustment device in which the front and rear wheels of a vehicle are held by a suspension and the suspension is expanded and contracted to maintain a constant posture of the vehicle, it is possible to prevent pedestrians from moving in the direction of travel of the vehicle while the vehicle is in motion. a detection means for detecting the pedestrian when the pedestrian appears; a determination means for determining the presence or absence of a collision with the pedestrian based on detection information obtained from the detection means and travel information of a vehicle approaching the pedestrian; and a determination means for determining whether there is a collision with the pedestrian. 1. A vehicle height adjusting device incorporating vehicle height lowering means for reducing a suspension on the basis of a determination result that there is a possibility of a collision, and lowering the vehicle height on the collision side immediately before a collision. (2) In the vehicle height adjustment device according to claim 1, the detection information is the distance to the pedestrian measured by the detection means, and the traveling information is the speed at which the vehicle approaches the pedestrian and the deceleration of the vehicle. A vehicle height adjustment device characterized in that the determination means determines whether or not there is a collision with a pedestrian based on this information. (3) The vehicle height adjusting device according to claim 1, wherein when activated, the vehicle height is lowered so that the bumper position of the vehicle is lower than the height of a pedestrian's knee.