JPH0921650A - State detector for moving body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a state detector for moving bodies which can highly accurately detect the correct gradient angle, velocity and travel distance highly precisely free from influences of temperature, humidity and vibration while angles are not accumulated even after a long stoppage. SOLUTION: Acceleration in the progressing direction of a moving body 1 is detected by an acceleration sensor 11, a pitching angular velocity in the progressing direction is detected by an angular velocity sensor 12, and a stoppage gradient angle when the moving body 1 stops is obtained based on the detected acceleration and gravitational acceleration of the earth. The stoppage gradient angle thus obtained is added to the amount of change in angle obtained by time-integrating an output from the angular velocity sensor 12, and the resultant angle is detected as gradient angle of the moving body in progress. An output from the acceleration sensor 11 may be subjected to time quadrature to provide velocity information on the moving body, or the velocity information may be subjected to time quadrature to be detected as travel distance information on the moving body 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving body state detecting apparatus, and more particularly to a moving body state detecting apparatus capable of measuring an inclination angle, a velocity and a moving distance without offset.

[0002]

2. Description of the Related Art Accelerometers and angular velocity sensors are mounted on a moving body such as a vehicle, and a device for obtaining a tilt angle, an angular velocity, and a moving distance of the moving body based on measurement data obtained from each sensor, including a car navigation system. It is attracting attention because it is useful in various fields.

In such an apparatus, the tilt angle of the moving body is obtained based on the angular velocity data obtained from the angular velocity sensor. Further, since the angular velocity sensor also reacts to the gravitational acceleration, it is possible to remove the influence of the gravitational acceleration while the moving body is running and extract only the motion acceleration.

[0004]

However, since the accuracy of the angular velocity sensor is affected by temperature and humidity, a slight offset occurs in its output. Further, since the angular velocity sensor also reacts to minute vibrations, output fluctuations occur. Therefore, the angle obtained based on the output from the angular velocity sensor may be accumulated as time elapses, and may be obtained as an output as if the vehicle was stopped on a steep slope even though it was stopped on a flat ground. Therefore, even if only the acceleration corrected by removing the influence of gravitational acceleration by the acceleration sensor by using the angle obtained by integrating the angular velocity detected by the angular velocity sensor, there is a deviation from the true value.

Further, Japanese Patent Application Laid-Open No. 2-194314 discloses a technique for correcting the output of the angular velocity sensor based on the output offset voltage of the angular velocity sensor when the moving body is stopped. However, in this technique, although offset correction is performed, the offset voltage remains as an error, and thus the error in the detected angle increases with the passage of time.

Therefore, an object of the present invention is that the influences of temperature, humidity and vibration are not exerted, and the angles are not accumulated even when the vehicle is stopped for a long time, and the accurate tilt angle, speed and movement distance can be detected with high accuracy. It is to provide a state detecting device for a moving body.

[0007]

In order to solve the above-mentioned problems, a state detecting device for a moving body of the present invention detects an acceleration sensor for detecting an acceleration in the traveling direction of the moving body and a pitching angular velocity in the traveling direction. The angular velocity sensor, the acceleration sensor output and a predetermined gravity acceleration of the earth is used to determine the stop inclination angle when the moving body is stopped, and the obtained stop inclination angle is the output of the angular velocity sensor. And a calculation means for calculating an angle obtained by adding to an angle change amount obtained by integration as an inclination angle of the moving body during traveling.

Further, there may be provided means for obtaining the speed information of the moving body by time-integrating the output of the acceleration sensor and means for obtaining the traveling distance information of the moving body by time-integrating the obtained speed information. it can.

[0009]

According to the present invention, the acceleration sensor detects the acceleration in the traveling direction of the moving body and the angular velocity sensor detects the pitching angular velocity in the traveling direction, and when the moving body is stopped based on the detected acceleration and the earth gravity acceleration. Determine the tilt angle at the stop. The stop inclination angle thus obtained is added to the angle change amount obtained by time integration of the output of the angular velocity sensor, and the obtained angle is detected as the inclination angle of the moving body during traveling. Further, the output of the acceleration sensor is integrated over time to obtain speed information of the moving body, or this speed information is integrated over time to be detected as traveling distance information of the moving body.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a basic configuration diagram of a state detecting apparatus for a moving body according to the present invention. An acceleration sensor 11 and an angular velocity sensor 12 are mounted on the moving body 1, and an inclination angle, a speed, a moving distance, etc. are based on outputs from these sensors. The mobile unit 1 is also equipped with a computing unit (not shown) for computing.

FIG. 2 shows an example of the configuration of the sensor mounted on the moving body and the arithmetic processing unit based on the sensor output in the embodiment shown in FIG. The acceleration signal and the angular velocity signal obtained by the acceleration sensor 11 and the angular velocity sensor 12 are converted into digital data by the A / D converter 13 and supplied to the CPU 15. Stop / running determination device 14
Determines the stop state and the running state of the moving body, and supplies the determination information to the CPU 15.

The acceleration sensor 11 detects acceleration in the traveling direction of the moving body, and the angular velocity sensor 12 detects pitching angular velocity in the traveling direction. The CPU 15 calculates the inclination angle, speed, running distance, etc. of the moving body based on the acceleration data and the angular velocity data obtained from the A / D converter 14, and the stop / judgment information from the stop / run judging device 14.

The operation and processing procedure of this embodiment will be described below with reference to FIGS. First, in a stationary state on a level ground, as shown in FIG. 3, the acceleration A from the acceleration sensor 11 is 0 [g] and the earth gravity g is 1. Therefore, in this case, the inclination angle θ, the acceleration A, and the earth gravity g Relational expression with g θ =
Substituting g = 1 and A = 0 into g · sin ⁻¹ A, θ = 0
Is obtained. The obtained angle θ is set as the pitching angle of the angular velocity sensor 12 (deflection angle in the traveling direction).

FIG. 4 shows an arithmetic processing procedure of the main routine of the CPU 15 under such conditions. After the operation is started, stop information is received from the stop / determination device 14 (step S1), and the motion acceleration a is set to 0 [g] (step S1).
2) The speed V is obtained by time integration of the acceleration a (step S3). In this case, since the acceleration a = 0, the velocity V also becomes 0. Further, the speed V is integrated over time to obtain the moving distance L (step S4).

Then, the output A (=
0 [g]) and the earth gravity g (= 1 [g]) (steps S5 and S6), the inclination angle θ is θ = g · sin ⁻¹ A [deg]
(Step S7), and θ = 0 is obtained in this case, so it is determined that the ground is flat (step S8). Meanwhile, the output ω from the angular velocity sensor 12 is received (step S9),
In step S10, w is integrated over time to obtain the angle θ (step S10). At this time, since ω = 0, the angle θ also becomes 0 [deg]. In this case also, since the moving body is stopped, the angle calculation in step 10 is not performed.

Next, the processing procedure when the moving body is stopped on a slope as shown in FIG. 5 will be described with reference to the flowchart of FIG. Each processing S11 to S20 in FIG.
The processing basically similar to each processing of S1 to S10 of FIG. 4 is shown. In this example, the slope angle is 5 degrees.

Upon receipt of stop information from the stop / travel determination device 14 (step S11), the motion acceleration A = 0 [g] in steps S12 to S14, its speed V and moving distance L are obtained. Then, the output A =-from the acceleration sensor 11
0.0872 [g] is received (step S15), the earth gravity acceleration g = 1 [g] is set (step S16), and the inclination angle θ is θ = g · sin ⁻¹ A [deg] at A = −0. 0872
[G] is substituted and calculation is performed to obtain θ = -5 [deg] (step S17). Obtained tilt angle θ = −5 [deg]
Is supplied as one parameter for calculating the angle in step S20. In this case also, since the moving body is stopped, each speed sensor output is ω = 0 [deg / s] (step 1
8), the angle calculation in step 20 is not performed.

Next, the processing procedure when the moving body starts traveling from the stopped state at the inclination angle θ [deg] will be described with reference to the flowchart of FIG.

When the stop / travel determination device 14 detects the traveling state of the moving body (step S21), the acceleration sensor 1
The sensor output A [g] from 1 is received (step S2
2), the earth gravity acceleration g = 1 [g] (step S2)
3), the motion acceleration a is obtained from a = A−g · sin θ ₀ [g] (step S24), the speed V is obtained by time-integrating the motion acceleration a (step S25), and the speed V is further time-integrated. The traveled distance L is obtained (step S26).

Further, the angular velocity output Δω [deg / s] from the angular velocity sensor 12 is detected (step S27), and this Δ
The angle change Δθ [deg] is obtained by integrating ω with time (step S29). On the other hand, the inclination angle at stop (step S28) obtained by the same processing as the processing of FIG. 6 is received, the inclination angle θ ₀ during traveling is obtained by θ ± Δθ (step S30), and the obtained inclination angle θ _{0 is} obtained. Is the calculation reference parameter of the motion acceleration in step S24.

[0021]

As described above, according to the state detecting device for a moving body of the present invention, the value of the acceleration sensor output obtained when the vehicle is stopped is used as the angle.
The influence of vibration can be eliminated, and the angles are not accumulated even if the vehicle is stopped for a long time, and an accurate tilt angle can be obtained. Also, the moving distance can be obtained with high accuracy.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a state detecting device for a moving body according to the present invention.

FIG. 2 is a configuration block diagram of the embodiment shown in FIG.

FIG. 3 is a diagram showing a positional relationship of moving bodies in a stationary state on a flat ground.

FIG. 4 is a flowchart showing a processing procedure of the embodiment of the present invention in the state of FIG.

FIG. 5 is a diagram showing a positional relationship of a moving body which is stopped on a slope.

FIG. 6 is a flowchart showing a processing procedure of the embodiment of the present invention in the state of FIG.

FIG. 7 is a flowchart showing a processing procedure of an embodiment of the present invention when a moving body starts traveling from a stopped state at an inclination angle θ [deg].

[Explanation of symbols]

 1 Mobile 11 Accelerometer 12 Angular Velocity Sensor 13 A / D Converter 14 Stop / Run Judgment Device 15 CPU

Claims (3)

[Claims] 1. An acceleration sensor for detecting an acceleration in a traveling direction of a moving body, an angular velocity sensor for detecting a pitching angular velocity in the traveling direction, and the movement based on an output of the acceleration sensor and a predetermined earth gravitational acceleration. The tilt angle at stop when the body is stopped is calculated, and the angle obtained by adding the calculated tilt angle at stop to the angle change amount obtained by time integration of the output of the angular velocity sensor A moving body state detecting device, comprising: a calculating unit that obtains an inclination angle. 2. The state detecting device for a moving body according to claim 1, further comprising means for obtaining speed information of the moving body by time-integrating the output of the acceleration sensor. 3. A means for calculating traveling distance information of the moving body by time-integrating the obtained speed information.
Alternatively, the state detecting device for a moving body according to 2 is provided.