JPS62209311A - Vehicle inclination and acceleration sensor - Google Patents

Abstract

PURPOSE:To operate not only the inclination of a vehicle upon reception of a stop signal from a car speed sensor but also acting acceleration upon reception of a running signal, by arranging a pressure-sensitive element between an inertial body and a receiving container. CONSTITUTION:A car speed 0 is inputted to a microcomputer (calculator) 12 from a car speed sensor 13 and, if a container 3 is inclined by an angle theta, the component force Mg sintheta of the wt. of an inertial body pressurizes a pressure-sensitive element 2a and a signal is inputted to the calculator 12. If the pressure and direction applied to each pressure-sensitive element 2 are synthesized as a vector, the moving direction and angle of inclination of the inertial body due to inclination are found. When the signal during running is inputted and the inertial body is accelerated to the right, the pressure-sensitive element 2a supplies a detection signal to operate acceleration and, when the inertial body is accelerated in the direction of an diagonal line FE, the elements 2a, 2b detect this state and calculate the intensity and direction of acceleration from the intensity and direction of pressure to output the same to an accelerometer 14 and various actuators 15. By this constitution, the inclination of the vehicle and the acceleration thereof in the horizontal direction can be detected with one apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle tilt acceleration sensor that detects the tilt and acceleration of a vehicle.

[Conventional technology]

Conventionally, in order to detect the inclination of a vehicle, etc., there has been an angle detection device as a tilt sensor as disclosed in Japanese Patent Application Laid-Open No. 58-21812, and in order to detect acceleration, there has been an angle detection device as a special acceleration sensor. There is one disclosed in JP-A-60-149976. If it is desired to detect the inclination and acceleration of the vehicle, these two types of sensors may be provided separately in the vehicle. However, since this requires two types of sensors to be installed in the vehicle, it is not the best method.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a vehicle tilt acceleration sensor that can selectively detect tilt and acceleration depending on the running state of the vehicle using one type of sensor.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention includes a container fixed to a vehicle, an inertial body housed in the container, and a multi-purpose inertial body disposed between the inertial body and the container. a plurality of pressure sensing elements that convert pressure exerted in a direction into an electrical pressure signal; a vehicle state detection means that generates first and second signals according to the state of the vehicle; and a vehicle state detection means that generates signals from the vehicle state detection means. Upon receiving the first signal, calculate the tilt direction and tilt angle of the vehicle based on the pressure signal from the pressure sensing element, and upon receiving the second signal from the vehicle state detection means, A technical means is adopted that includes a calculation means for calculating the acceleration direction and acceleration acting on the vehicle based on the pressure signal from the pressure sensing element.

[Effect]

In the device of the present invention, a vehicle state detecting means detects a state such as whether the vehicle is stopped or running, and a first
Based on the second signal, the calculating means determines whether to calculate the slope or the acceleration from the pressure signal from the pressure sensitive element. Then, either inclination or acceleration is selectively calculated from the pressure signal from the pressure sensitive element. Here, in the present invention, the direction of inclination and acceleration of the vehicle is calculated by combining respective pressure signals received by a plurality of pressure sensing elements from an inertial body.

〔Effect of the invention〕

The present invention combines a plurality of pressure-sensitive elements and an inertial body, and determines whether the pressure signal detected by the pressure-sensitive element depends on the inclination of the vehicle or acts on the vehicle depending on the state of the vehicle. Therefore, tilt and acceleration can be selectively detected without separately providing a tilt sensor and an acceleration sensor.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

This embodiment is a vehicle sensor that is combined with a vehicle speed sensor serving as a vehicle state detection means, and operates as an inclination sensor when the vehicle is stopped, and as an acceleration sensor of the vehicle when the vehicle is running.

First, FIGS. 2 and 3 are cross-sectional views of the vehicle sensor main body S of this embodiment.

The container 3 consists of a box 3a whose internal horizontal cross section is square and a lid 3b. This box body 3a is fixed to a horizontal surface of a part of the vehicle body 4, and a first pressure sensitive element 2a is fixed to a first side surface A inside this box body 3a with an adhesive, and a second pressure sensitive element 2a is fixed to a side surface B of the cylinder 2. A third pressure sensitive element 2C1 is fixed to the third side surface C, and a fourth pressure sensitive element 2d is fixed to the fourth side surface C by adhesive. A sphere l having a size that contacts the inner surfaces of all the pressure sensitive elements 2 is placed in the box 3a to which these pressure sensitive elements 2 are fixed, and is covered with a lid 3b. Here, the sphere 1 is made of iron and acts as an inertial body, and has enough mass to deform the pressure-sensitive element in the direction of movement of the sphere 1 when the box 3 is tilted or when it receives acceleration from the outside. have.

FIG. 4 is a sectional view of the pressure sensitive element 2 of this example. This pressure-sensitive element 2 includes a plate-shaped pressure-sensitive conductive rubber 31 that is deformed by pressure and changes its electrical resistance value, and two deformable flat plate electrodes 32 and 33 provided on both sides of the rubber. It consists of an insulating sheath 34 covering it. The plate electrodes 32.33 are then connected to leads, vI35.36.

In addition, Fig. 2.

In FIG. 3, the lead wires 35 and 36 of each pressure-sensitive element 2 are taken out all at once from a hole provided in the box body 3a, but for convenience, this illustration is omitted in FIGS. 2 and 3. did. As shown in FIG. 5, these pressure-sensitive elements 2 have a characteristic that as the pressure F that deforms the pressure-sensitive element 2 increases, the electrical resistance value R decreases.

FIG. 1 is a block diagram showing the entire system of a vehicle tilt acceleration sensor including the vehicle sensor main body S described above. Changes in the resistance value of each pressure-sensitive element 2 of the vehicle sensor S are input as changes in electric fields to an A-D converter 1), where they are digitally converted and sent to a microcomputer 12, which is a calculation means.
is input.

The microcomputer 12 receives an electrical signal from a vehicle speed sensor 13 that corresponds to the vehicle speed. The output of the microcomputer 12 is connected to a meter 14 such as an inclinometer or an accelerometer that displays the state of the vehicle, an actuator that controls a shock absorber, and a buzzer that notifies the state of inclination.

Hereinafter, the operation of this embodiment will be explained in detail based on the drawings.

First, when the first electrical signal from the vehicle speed sensor 13 indicating that the vehicle speed is O is input to the microcomputer 12, the vehicle sensor S operates as a tilt sensor.

Assume that the right side of the vehicle sensor S in FIG. 3 is raised at an angle θ. If the mass of sphere 1 is M and the gravitational acceleration is g, then
Its weight ff1Mg is tilted by θ as shown in the figure, and the box body 3a
A component force Mg cos θ in the direction of the bottom surface and a component force 1v (g sin θ) in the direction of the first side surface A are generated.
The first pressure sensitive element 2 fixed to the first side surface A by nθ
is deformed, and the change in resistance value due to this deformation is input to the microcomputer 12 as a change in voltage. The microcomputer 12 determines the pressure applied to the first pressure-sensitive element 2a from this voltage, and further calculates the angle and direction of inclination of the container 3, that is, the vehicle 4, relative to the gravitational acceleration.

Assuming that the point E on the upper right side of the vehicle sensor S in FIG. 2 is tilted at a high angle θ with the point F on the lower left side as a fulcrum, the weight of the sphere 1 is between the bottom surface of the box body 3a and the first side surface A. and a component force in the direction of the second side surface B is generated. With this component force, the first
The pressure sensitive element 2 and the second pressure sensitive element 2 are deformed, and the change in their respective resistance values is input to the microcomputer 12 as a change in voltage. The microcomputer 12 determines the pressure applied to each pressure sensitive element 2a, 2b, and calculates the tilt angle and tilt direction of the vehicle 4 with respect to the weight acceleration from these. Depending on the relative positional relationship between each pressure sensitive element 2 and the sphere 4, the distribution of pressure that each pressure sensitive element 2 receives from the sphere 4 changes depending on the angle and direction of inclination. Therefore, by combining the pressure and direction applied to each pressure-sensitive element 2 as a vector, the direction in which the sphere 4 moves due to the inclination can be determined, and the angle and direction of the inclination can be determined.

Then, the results of these calculations are output to the inclinometer 14,
Informs the driver of the vehicle's inclination. Further, if it is determined that the tilt at this time is a dangerous angle for driving the vehicle or an abnormal tilt due to theft or the like, the buzzer 15 sounds.

Next, the electric signal of the vehicle speed sensor 13 indicates that the vehicle speed is not O,
When the second signal indicating that the vehicle is in a running state is input to the microcomputer 12, the vehicle sensor S operates as an acceleration sensor. Assume that the vehicle 4 accelerates to the right in FIG. Then, since the container 3 is fixed to the vehicle 4 and the sphere 1 inside has inertia, the sphere 1
tries to move toward the left side in FIG. 3, that is, toward the first side A. Then, the first pressure sensitive element 2a located between it and the first side surface A in this moving direction is deformed.

The microcomputer 12 detects a change in resistance value due to the deformation of the first pressure sensitive element 2 as a change in voltage. The microcomputer 12 determines that the sphere 1 is the first
The pressure that deforms the pressure sensitive element 2 is determined, and the magnitude of the acceleration in the opposite direction is calculated.

Assuming that acceleration is applied from point F to point A in FIG. Transform. The microcomputer 12 detects the change in resistance value due to this deformation as a change in voltage, and determines the shape of the sphere 1 based on the direction and strength of the pressure that deforms each pressure-sensitive element 2.
The direction and magnitude of the acceleration acting on the object are calculated and synthesized.

Then, the results of these calculations are output to the accelerometer 14, various actuators 15, etc. that operate according to this acceleration.

With the above-described configuration and operation, this practical example can detect the inclination and horizontal acceleration of the vehicle 4 using one vehicle sensor S.

Further, the vehicle sensor S of this embodiment has a simple structure, and uses pressure-sensitive conductive rubber, which is an elastic body, as the pressure-sensitive element 2, and the spherical body 1, which is the only movable part, is in contact with the pressure-sensitive element 2. Since the movement range is limited to the range in which the pressure sensitive element 2 deforms, it has excellent mechanical strength and has a small detection error against vibrations and the like.

In this embodiment, the pressure-sensitive elements 2 are provided at four vertical surfaces of a cube circumscribing the sphere 1, as shown in FIG.

As shown in FIG. 7, the pressure sensitive elements 2 may be provided at three vertical surfaces of a triangular prism circumscribing the sphere 1.

Further, by disposing the pressure sensitive element 2 at each surface of a polyhedron of tetrahedron or more that circumscribes the sphere 1, it is possible to detect acceleration in all directions including vibrations in the vertical direction. Also,
Although the pressure-sensitive element of this embodiment utilizes the pressure-resistance characteristics of pressure-sensitive conductive rubber, it may also utilize a piezo semiconductor generally called a piezoelectric element. In addition, the vehicle condition detection means is not limited to the vehicle speed sensor, but also uses a rotation sensor that detects whether the engine is operating or a sensor that detects the presence or absence of the driver. It is also possible to generate a second signal indicating these, and generate a first signal at other times, so that acceleration and inclination can be detected separately.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure is a horizontal cross-sectional view of a vehicle sensor according to an embodiment, FIG. 3 is a cross-sectional view taken along the line nn in FIG. 2, and FIG. 5 is a characteristic diagram showing the relationship between the pressure-sensitive element and the pressure car grinding force shown in FIG. 4, FIG. 6 is a horizontal sectional view of a vehicle sensor of another embodiment, and FIG. 7 is a VI of FIG. 6. -Vl sectional view. S... Vehicle sensor, 1... Inertial body, 2... Pressure sensitive element. 3... Container, 4... Vehicle body, 12... Calculating means, 1
3...Vehicle state detection means. Representative Patent Attorney Takashi Okabe S: Excellent L4 1) 1.4 Parrot 2: S Pressure! #, ↓ 3:9 Vessel 4: Car 梼+2: ! fA N 4-n 13: Warehouse 1) Koukasahi Kinde Techin Figure 1

Claims (2)

[Claims] (1) A container fixed to a vehicle, an inertial body housed in this container, and an electrical pressure signal that is placed between this inertial body and the container and measures the pressure exerted by this inertial body in multiple directions. a plurality of pressure sensing elements for converting the pressure into the vehicle; vehicle state detection means for generating first and second signals in accordance with the state of the vehicle; and upon receiving the first signal from the vehicle state detection means, the The direction and angle of inclination of the vehicle are calculated based on the pressure signal from the pressure sensing element, and upon receiving the second signal from the vehicle state detection means, the pressure signal from the pressure sensing element is calculated. 1. A vehicle tilt acceleration sensor, comprising: calculation means for calculating an acceleration direction and acceleration acting on the vehicle based on the above information. (2) A patent characterized in that the vehicle state detection means is a vehicle speed sensor that generates a stop signal indicating the vehicle stop state as the first signal and a running signal indicating the vehicle running state as the second signal. A vehicle tilt acceleration sensor according to claim 1.