JPH06281457A - Inclination measuring device - Google Patents

Abstract

PURPOSE:To remove an inclination effect of an acceleration sensor by synthesizing acceleration in the direction of a contact ground surface, and acceleration in the direction perpendicularly intersected with the aforesaid direction of the contact ground surface, calculating the angle formed by both the vectors of synthesized acceleration and gravity acceleration, and an angle formed by both the vectors of synthesized acceleration and acceleration in the ground surface direction, and thereby adding both the aforesaid angles to derive the inclination. CONSTITUTION:A first and a second acceleration sensors 2 and 3 are disposed at the same position of a motorbicycle 1, and in this case, this constitution thereby eliminates a need for taking the dimension of the mounting position of the sensors 2 into consideration because an inclination theta is operated based on an angle alpha formed by the vector of the synthesized acceleration (a) of acceleration G1 and G2 detected by the sensors 2 and 3 and gravity acceleration (g), and an angle beta formed by the vector of acceleration G1 and synthesized acceleration (a). As a result, the sensors 2 and 3 can thereby be easily mounted. This constitution thereby eliminates troublesomeness to select the mounting positions of the acceleration sensors 2 and 3 with respect to a car body, or to take mounting accuracy into consideration in order to avoid adverse effect to an inclination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tilt angle measuring device mounted on a motorcycle, particularly when the number of acceleration sensors to be mounted on the motorcycle is reduced and the vehicle speed sensor is not required. The present invention relates to a suitable tilt angle measuring device.

[0002]

2. Description of the Related Art Conventionally, as a tilt angle measuring device mounted on a motorcycle, for example, a device described in JP-A-60-60512 has been proposed. The tilt angle measuring device described in the publication is based on the outputs of two acceleration sensors arranged on the upper part of the motorcycle body and one acceleration sensor and a vehicle speed sensor arranged on the lower part of the motorcycle. This is a device that can measure the inclination angle of the vehicle while running without influence of centrifugal force.

The principle of measuring the tilt angle by the conventional tilt angle measuring device will be described. For example, as shown in FIG. 5, first to third acceleration sensors 51, 51 mounted on the vehicle body of the motorcycle 50 are used.
The detection outputs of 52 and 53 are A1, A2, A3, the detection output of a vehicle speed sensor (not shown) mounted on the vehicle body is V, and the height from the ground to the first acceleration sensor 51 or the second acceleration sensor 52 is L1, The distance from the surface forming the center of the vehicle body to the first acceleration sensor 51 and the second acceleration sensor 52 is L
2. When the height from the ground to the third acceleration sensor 53 is L3, the inclination angle θ of the vehicle body is θ = arctan [{(V ² / A ³ ) · ΔA-L1} /
(L1-L3)] (where ΔA: | A3-A1 | or | A3-A2 |).

[0004]

However, in the above-described conventional tilt angle measuring device, since the calculation formula of the vehicle body tilt angle of the motorcycle includes the mounting dimensions of each acceleration sensor, each acceleration with respect to the vehicle body is increased. Whether or not the mounting position (dimension) of the sensor is appropriate affects the measurement of the tilt angle, and it is actually difficult to mount each acceleration sensor on the vehicle body so as not to affect the measurement of the tilt angle. There was a problem. Further, when measuring the inclination angle of the vehicle body, a large number of acceleration sensors and vehicle speed sensors are required as described above, which causes a problem that the number of parts is increased and the cost is increased. Furthermore, when calculating the vehicle speed by detecting the number of rotations of the wheel of the motorcycle with a vehicle speed sensor, the circumference of the wheel changes apparently when the vehicle body leans due to cornering or the inclination of the road surface, so the accurate vehicle speed is detected. There was a problem that it was difficult to do.

[0005]

It is an object of the present invention to improve the disadvantages of the above-mentioned conventional example, in particular, to eliminate the influence of the mounting position of the acceleration sensor on the measurement of the inclination angle of the vehicle body, and to reduce the number of the acceleration sensors. An object of the present invention is to provide a tilt angle measuring device that does not require a vehicle speed sensor.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a first acceleration sensor for detecting an acceleration in the ground contact road direction along a plane that passes through the center of a vehicle body and divides the vehicle body longitudinal direction into left and right directions. A second acceleration sensor which is arranged at the same position as the first acceleration sensor and detects an acceleration in a direction orthogonal to the surface; and the respective accelerations detected by the first and second acceleration sensors are combined and combined. A function to calculate acceleration,
A function of calculating an angle formed by the vector of the combined acceleration and a vector of the gravitational acceleration acting on the vehicle body, and a function of calculating an angle formed by the vector of the combined acceleration and the vector of the acceleration detected by the first acceleration sensor; It is configured to include a calculating means having a function of adding both angles and calculating the inclination angle of the vehicle body. This is intended to achieve the above-mentioned object.

[0007]

According to the present invention, the first and second acceleration sensors are arranged at the same position (one location) on the vehicle body, and the vector of the combined acceleration of the accelerations detected by the respective acceleration sensors and the vector of the gravitational acceleration. And the angle formed by the vector of the synthetic acceleration and the vector of the acceleration detected by the first acceleration sensor are added to calculate the lean angle of the vehicle body. It is not necessary to consider the dimensions of the mounting position of each acceleration sensor, which eliminates the influence of the mounting position and mounting accuracy of each acceleration sensor on the vehicle body. It will be easy. Therefore, it is possible to eliminate the complexity of selecting the mounting position of the acceleration sensor with respect to the vehicle body and considering the mounting accuracy in order to avoid the influence on the inclination angle as in the conventional case. Further, according to the present invention, since only two acceleration sensors need to be mounted on the vehicle body, the number of acceleration sensors provided can be reduced as compared with the conventional one.
Since the vehicle speed data is not used in the calculation of the vehicle body inclination angle, it is not necessary to dispose a vehicle speed sensor as in the conventional case, and it is possible to avoid the influence of the vehicle speed on the vehicle body inclination angle measurement. Further, it is possible to reduce the number of parts such as sensors, and it is possible to reduce the cost.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment to which the tilt angle measuring device of the present invention is applied will be described below with reference to the drawings.

First, the structure of a motorcycle equipped with the tilt angle measuring apparatus of this embodiment will be described with reference to FIGS. 2 and 3. The motorcycle 1 passes through the center of the vehicle body and the front-rear direction of the vehicle body is moved left and right. A first acceleration sensor 2 arranged in the direction of the ground contact road along the bisecting plane, and a first acceleration sensor 2 arranged at the same position as the first acceleration sensor 2 and passing through the center of the vehicle body of the vehicle body. Two acceleration sensors, that is, a second acceleration sensor 3 arranged in a direction orthogonal to a plane that divides the front-rear direction into left and right, are provided. That is, the greatest feature of this embodiment is that the first and second acceleration sensors 2 and 3 are arranged at the same position on the vehicle body. In this case, the mounting positions of the first and second acceleration sensors 2 and 3 with respect to the vehicle body can be arbitrary positions that do not interfere with traveling or the like, and the mounting positions are not selected. Reference numeral 4 in the figure
Is a wheel and reference numeral 5 is a seat cowl.

Next, the structure of the inclination angle measuring device of this embodiment mounted on the motorcycle 1 will be described with reference to FIG. 1. The inclination angle measuring device is composed of a first acceleration sensor 2, a second acceleration sensor 3, A / It is configured to include a D converter 6, a computer 7 including, for example, a microcomputer, a tilt direction determination element 8, a steering sensor, and a display (not shown). In this case, the A / D converter 6, the arithmetic unit 7, the inclination direction determination element 8, and the display device are arranged in a predetermined position of the motorcycle 1, for example, inside the instrument panel.

The configuration of the tilt angle measuring device will be described in detail below.
The acceleration sensor 2 detects the acceleration in the ground contact road direction along a plane that passes through the center of the vehicle body of the motorcycle 1 and divides the front-rear direction of the vehicle body into left and right parts, and the detected acceleration G1 (analog signal) is A / D. It is designed to output to the converter 6. The second acceleration sensor 3 detects an acceleration in a direction orthogonal to a plane that passes through the center of the vehicle body of the motorcycle 1 and divides the front-rear direction of the vehicle body into two halves, and the detected acceleration G2 (analog signal) is A / D. It is designed to output to the converter 6. The A / D converter 6 includes the first acceleration sensor 2
Also, the acceleration output from the second acceleration sensor 3 is converted from analog to digital, and the accelerations G1 and G2 are output to the calculator 7.

The tilt direction determining element 8 is based on steering angle information of the steering wheel of the motorcycle 1 detected by the steering sensor or information of a test course on which the motorcycle 1 is traveling (information such as a bank direction which is known in advance). The inclination direction of the vehicle body (the direction of the bank) is determined, and the determined inclination direction data is output to the computer 7.
The arithmetic unit 7 has an acceleration G1 detected by the first and second acceleration sensors 2 and 3 output from the A / D converter 6.
The inclination angle of the vehicle body of the motorcycle 1 is calculated based on the inclination direction data output from G2 and the inclination direction determination element 8,
The calculated tilt angle is displayed and output from a display device or the like.

Next, the process of measuring the lean angle of the motorcycle body by the lean angle measuring apparatus of the present embodiment having the above-described structure will be described with reference to FIGS. 3 and 4.

For example, it is assumed that the vehicle body is tilted in the state shown in FIG. 3 due to cornering of the motorcycle 1 and inclination of the road surface. A first acceleration sensor 2 arranged on the vehicle body of the motorcycle 1 detects acceleration in the direction of the ground contact road along a plane that passes through the center of the vehicle body of the motorcycle 1 and divides the longitudinal direction of the vehicle body into left and right parts. The second acceleration sensor 3 detects acceleration in a direction orthogonal to a plane that passes through the center of the vehicle body of the motorcycle 1 and divides the front-rear direction of the vehicle body into left and right parts, and the detected accelerations G1 and G2 are A / D converters. 6
To the acceleration G1, G
2 is analog-to-digital converted and output to the calculator 7.

The computer 7 reads the acceleration G1 detected by the first acceleration sensor 2 based on the output of the A / D converter 6 (step S1), and calibrates the gravitational acceleration g based on the acceleration G1 (step S2). In this case, since the gravitational acceleration g changes depending on whether or not the traveling road is at high altitude, the gravitational acceleration g is calibrated. Next, the computer 7
The acceleration G1 detected by the first acceleration sensor 2 is read based on the output of the / D converter 6 (step S
3), the acceleration G2 detected by the second acceleration sensor 3 is read based on the output of the A / D converter 6 (step S4).

Next, the arithmetic unit 7 obtains a synthetic acceleration a obtained by synthesizing the acceleration G1 detected by the first acceleration sensor 2 and the acceleration G2 detected by the second acceleration sensor 3 by: a = (G1 ² + G2 ² ) ¹ Calculate with the formula ^{/ 2} . Further, the angle α formed by the vector of the gravitational acceleration g and the vector of the synthetic acceleration a is calculated by the formula α = cos ⁻¹ (g / a). Further, the angle β formed by the vector of the acceleration G1 detected by the first acceleration sensor 2 and the vector of the synthetic acceleration a is calculated by the equation β = tan ⁻¹ (G2 / G1) (step S5). In this case, what is indicated by reference character E in FIG. 3 is a centrifugal force that acts on the vehicle body of the motorcycle 1.

Next, the computing unit 7 determines the tilt direction (bank direction) of the vehicle body based on the steering angle information of the motorcycle 1 detected by the steering sensor or the course information of the motorcycle 1 traveling. Based on the inclination direction data output from the direction determination element 8, it is determined whether the inclination direction of the vehicle body of the motorcycle 1 (bank direction) is inclined "left" or "right" (step S6). ), If it is determined that the vehicle body tilt direction (bank direction) is "left", the angle "α" formed by the gravitational acceleration g and the synthetic acceleration a is set to "-α" (step S7). In this case, "+ α" is set when the vehicle body tilt direction (bank direction) is "right".

Next, when it is determined that the inclination direction (bank direction) of the vehicle body of the motorcycle 1 is inclined to the "right", the arithmetic unit 7 calculates the inclination angle θ as θ = α + β. . On the other hand, when it is determined that the leaning direction of the vehicle body of the motorcycle 1 (the direction of the bank) is leaning “left”, the leaning angle θ is calculated as θ = −α + β (step S8). After that, the calculator 7 outputs the calculated tilt angle of the vehicle body of the motorcycle 1 from a display or the like arranged on the instrument panel or the like of the motorcycle 1 (step S9).

As described above, according to the tilt angle measuring apparatus of this embodiment, the first and second acceleration sensors 2 and 3 are arranged at the same position (one place) on the vehicle body of the motorcycle 1, and
The angle α formed by the vector of the synthetic acceleration a of the accelerations G1 and G2 detected by the first and second acceleration sensors 2 and 3 and the vector of the gravitational acceleration g, and the vector of the acceleration G1 and the vector of the synthetic acceleration a. Since the inclination angle θ is calculated based on the angle β, in other words, when calculating the inclination angle θ of the vehicle body, it is not necessary to consider the size of the mounting position of each acceleration sensor as in the conventional case. The first and second acceleration sensors 2 and 3 are not affected by the mounting position and the mounting accuracy of the first and second acceleration sensors 2 and 3, and as a result, the first and second acceleration sensors 2 and 3 are easily mounted to the vehicle body. Therefore, it is possible to eliminate the complexity of selecting the mounting position of the acceleration sensor with respect to the vehicle body and considering the mounting accuracy in order to avoid the influence on the inclination angle as in the conventional case.

Further, according to the tilt angle measuring apparatus of this embodiment, the number of sensors to be mounted on the vehicle body of the motorcycle 1 is only two acceleration sensors, so that the number of acceleration sensors provided is reduced as compared with the conventional one. Further, since the vehicle speed data is not used for calculating the inclination angle of the vehicle body of the motorcycle 1, it is not necessary to dispose a vehicle speed sensor and the influence of the vehicle speed on the measurement of the inclination angle is avoided. Further, it is possible to reduce the number of parts and to reduce the cost.

[0021]

As described above, according to the tilt angle measuring device of the present invention, the effects of the following items can be obtained. The first and second acceleration sensors are arranged at the same position (one location) on the vehicle body, and the angle formed by the vector of the combined acceleration of the acceleration detected by each acceleration sensor and the vector of the gravitational acceleration, and the vector of the combined acceleration The angle formed by the acceleration vector detected by the first acceleration sensor and the vector formed by the first acceleration sensor is added to calculate the lean angle of the vehicle body. Since it is not necessary to consider the dimensions of
It is not affected by the mounting position or the mounting accuracy of each acceleration sensor on the vehicle body, and as a result, the mounting of each acceleration sensor on the vehicle body becomes easy. Therefore, unlike the conventional case, it is possible to eliminate the complexity of selecting the mounting position of the acceleration sensor with respect to the vehicle body and considering the mounting accuracy in order to avoid the influence on the inclination angle. Further, since only two acceleration sensors need to be mounted on the vehicle body, the number of acceleration sensors provided can be reduced as compared with the conventional one, and the vehicle speed data is used when calculating the inclination angle of the vehicle body. Therefore, it is not necessary to dispose a vehicle speed sensor as in the conventional case, and it is possible to avoid the influence of the vehicle speed on the measurement of the lean angle of the vehicle body.
Further, it is possible to reduce the number of parts such as sensors, and it is possible to reduce the cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a tilt angle measuring device according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a mounting state of an acceleration sensor on a motorcycle equipped with the tilt angle measuring device of the present embodiment.

FIG. 3 is an explanatory view showing a state where the motorcycle shown in FIG. 2 is inclined.

FIG. 4 is a flowchart of a tilt angle measuring process by the tilt angle measuring device according to the present embodiment.

FIG. 5 is an explanatory view showing a mounting state of an acceleration sensor and a vehicle speed sensor on a motorcycle in a conventional example.

[Explanation of symbols]

 1 Motorcycle 2 1st Acceleration Sensor as 1st Acceleration Sensor 3 2nd Acceleration Sensor as 2nd Acceleration Sensor 6 A / D Converter 7 Computation Machine as Computation Means 8 Tilt Direction Judgment Element

Claims (3)

[Claims] 1. A first acceleration sensor for detecting an acceleration in a ground road surface direction along a plane that passes through a center portion of the vehicle body and divides the vehicle body in the front-rear direction into left and right, and at the same position as the first acceleration sensor. A second acceleration sensor arranged to detect an acceleration in a direction orthogonal to the plane; a function of combining the accelerations detected by the first and second acceleration sensors to calculate a combined acceleration; A function of calculating an angle formed by a vector of the synthetic acceleration and a vector of the gravitational acceleration acting on the vehicle body, a function of calculating an angle formed by the vector of the synthetic acceleration and a vector of the acceleration detected by the first acceleration sensor, and the both angles. A tilt angle measuring device comprising: a calculating unit having a function of calculating the tilt angle of the vehicle body by adding 2. The calculation means determines whether the angle formed by the vector of the combined acceleration and the vector of the gravitational acceleration is a positive value or a negative value based on whether the leaning direction of the vehicle body is the right side or the left side. The tilt angle measuring device according to claim 1, further comprising a function of: 3. The tilt angle measuring device according to claim 1, wherein the calculation means has a function of outputting the calculated tilt angle of the vehicle body from a predetermined output means to the outside.