JPH0395407A - Gyro device - Google Patents

Abstract

PURPOSE:To enable accurate detection of a direction by detecting a drift component of an angular velocity sensor approximately as continuous data and by subtracting this drift component from an output of the angular velocity sensor. CONSTITUTION:An output of an angular velocity sensor 11 is sampled by a control signal from a stop detecting circuit 15 and supplied to a memory 14. An approximation estimating circuit 16 interpolates the sensor output at the time of a stop stored in the memory 14, so as to make it approximate to continuous data, and also estimates the amount of a change. Based on the interpolated data, besides, this circuit estimates the amount of a change in data thereafter. The data estimated in approximation from the sensor output at the time of the stop in the estimating circuit 16 are taken as drift data. Then, the output of the sensor 11 once stored in the memory 12 is supplied to a subtracter 17, while the data estimated in approximation by the estimating circuit 16 are supplied to the subtracter 17, and an output of subtraction is supplied as an angular velocity data detection output of a gyro device 10 to an integrating circuit 21. Based on the angular velocity data obtained in this way and not containing a drift component practically, accurate detection of a direction can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a gyro device applied to a navigation device of, for example, an automobile.

[Summary of the invention]

The present invention detects the drift command of the angular velocity sensor as continuous data in a gyro device using an angular velocity sensor applied to a navigation device, for example, and subtracts this drift command from the output of the angular velocity sensor to obtain angular velocity data. This makes it possible to obtain accurate angular velocity data.

[Conventional technology]

In recent years, various navigation devices have been developed to be mounted on automobiles. For example, the position of the own vehicle is determined by detecting the direction of travel of the vehicle from the starting point, the amount of travel, etc.
This determined road map in the vicinity of your vehicle's position is stored on a CD RO.
It is conceivable to display information on a display device based on information from a mass storage device such as an M device.

[Problem to be solved by the invention]

It is conceivable to use a gyro device as a driving direction detection device used in such a car navigation system, but a car navigation system needs to be constructed at a relatively low cost. A gyro device is used.

This low-accuracy gyro device has the disadvantage that an error called 0-point drift occurs in the detection output. That is, for example, when the angular velocity generated by the running of a car is in the state shown in FIG. 5A, a drift component that gradually increases as shown in FIG. 5B occurs, and the actual output of the gyro device is as follows. As shown in FIG. 6A, a drift component is superimposed on this angular velocity data.

For this reason, it is necessary to remove the drift component from the detection output, but the detection output becomes only the drift l-1 minutes only when the car is stopped, and when the car is temporarily stopped at an intersection etc. Sometimes, the offset was set to O by detecting this Drift 1/Kibun. For example, if the car stops temporarily at jl+t2 (see Figure 6A) after it starts running, the detection output can be reset to 0 at t1 and t2 as shown in Figure 6B. Then, each time the car temporarily stops, the drift Iffl is removed and the drift weight is no longer accumulated.

However, even if the drift component is removed at the time of stopping in this way, the drift I-Kibun still accumulates between the start of running and the time of stopping, and the detected data shown in Fig. 6B and Fig. 5A There is a difference between the actual angular velocity data shown in the actual driving conditions and the original angular velocity data.

In view of this point, it is an object of the present invention to remove the Drift 1 component to enable good direction detection.

[Means for Solving the Problem] As shown in FIG. 1, for example, a gyro device of the present invention detects the moving direction of a moving body based on the output of an angular velocity sensor (11).
) is approximately detected as continuous data, and this trifle I-command is subtracted from the output of the angular velocity sensor (11) by a subtracter (17) to obtain angular velocity data. .

(Operation) According to this structure, the drift 1 and the predetermined value are continuously subtracted from the output of the angular velocity sensor, angular velocity data with almost no drift component is obtained, and accurate direction detection can be performed based on this angular velocity data.

(Embodiment) Hereinafter, one embodiment of the gyro device of the present invention will be described with reference to FIGS. 1 to 3.

In this example, the present invention is applied to a navigation system for an automobile, and the structure is as shown in FIG.

In FIG. 1, (10) indicates the entire gyro device, which is mounted on an automobile and detects angular velocity data based on the output of an angular velocity sensor (11).

That is, the output of the angular velocity sensor (11) is stored in the memory (12).
) and stored in the memory (14) via the Zumble/Hold circuit (13). In this case, the sampling timing in the sample/hold circuit (13) is controlled by a stop detection circuit (15) that detects the stopped state of the vehicle, and when the stop detection circuit (15) detects the stopped state of the vehicle, the sampling timing is The signal is supplied to a sample and hold circuit (13), and by supplying this sampling control signal, the output of the angular velocity sensor (11) is sampled and supplied to a memory (14). Then, the output signal of the memory (14) is supplied to the approximate estimation circuit (16). This approximate estimation circuit (16) is connected to a memory (14).
) is a circuit that approximates continuous data and estimates the amount of change by interpolating the sensor output at the time of stop stored in Interpolation is wrong. Also, based on the interpolated data, the amount of subsequent change in data is estimated. This approximate estimation circuit (1
The data approximated from the sensor output when stopped in 5) is
Use it as drift data.

Then, the output of the angular velocity sensor (11) temporarily stored in the memory (12) is supplied to the subtracter (l7), and the data approximately estimated by the approximate estimation circuit (16) is supplied to the subtracter (1).
7), the approximate estimated drift data is subtracted from the angular velocity data detected by the angular velocity sensor (11), and the subtracted output is supplied to the integrating circuit (21) as the angular velocity data detection output of the gyro device (10).

The integrating circuit (21) then integrates the angular velocity data supplied from the gyro device (10) to detect the running direction. That is, if the running direction at the starting point can be determined, the current running direction can be detected by correcting the running direction at the starting point by integrating the angular velocity data. Then, the driving direction data outputted by the integrating circuit (21) is supplied to the current position detection circuit (22), and furthermore, the driving distance data of the car detected by the distance sensor (23) is supplied to the current position detection circuit (22).
). By doing so, the current position detection circuit (22) can detect the current coordinate position of the automobile, and by supplying display data based on the detected coordinate position to the display device (24), the display device (24) can display data based on the detected coordinate position. The current location is displayed on the screen of the device (24) along with a road map and the like.

Next, to explain the operation when detecting the position of a car equipped with this navigation device, the current position detection circuit (22) uses the driving direction data supplied from the integrating circuit (21) and the distance sensor (23). Based on the supplied travel distance data, the coordinate position of the starting point is moved to constantly detect the current position.

Here, the running direction data is obtained by integrating the angular velocity data output by the gyro device (10) by the integrating circuit (21). The angular velocity data output by (11) includes a drift component.Suppose that the angular velocity data including this drift component is obtained, for example, as shown in Fig. 2A.This angular velocity data can be used as it is. The data is stored as continuous data in the memory (12), and the angular velocity data at the time when the stop detection circuit (15) detects the stop of the vehicle is sampled by the sample/hold circuit (14) and stored in the memory (14).
). For example, t1 in the running data in Figure 2A
If the car stops at t2 and t3, this t+,
The angular velocity data of tz and t3 are stored in the memory (14). Then, interpolation processing of the angular velocity data of 5, t2, and t3 is performed in the approximate estimation circuit (16) as shown by the solid line in FIG. 2B. In this case, the starting point data is set to “0”.
and is connected by a straight line from the starting point at each stop. Also,
Based on data 1+, 12, . . . at each stop, the amount of change in angular velocity until the car stops next time is estimated. For example, when the angular velocities at two points 1, 12 can be detected as data at the time of stopping, as shown in FIG. The angular velocity X after t2 is estimated based on the amount of change in angular velocity up to and the amount of change in angular velocity from t1 to t2.

Then, by subtracting the drift data obtained by this approximate estimation from the angular velocity data once stored in the memory (12), angular velocity data from which the drift component has been removed is obtained as shown in FIG. 2C.

In this case, in the tree example, the drift data to be subtracted is
Since the data at each stop is made into continuous data by the above-mentioned approximate estimation, angular velocity data with drift components removed continuously can be obtained, and accurate angular velocity data with extremely low drift components can be obtained from the gyro device (10). Output. Therefore, even if an inexpensive angular velocity sensor (l1) that generates a large amount of drift components is used as the angular velocity sensor (l1) incorporated in the gyro device (lO), accurate angular velocity data can be obtained and a navigation device that can accurately detect the position is possible. It can be maintained cheaply.

In the above embodiment, the approximate estimation circuit (16) connects each piece of data with a straight line.
It is also possible to use polynomial arithmetic processing to connect the curves with quadratic or higher order curves, and obtain a value closer to the actual drift component as shown by the broken line in FIG. 2B. By doing so, more accurate angular velocity data can be obtained.

In addition, in the above embodiment, the drift component is detected from the sensor output when the car stops, but even if the drift component is extracted by taking advantage of the fact that the drift component fluctuates relatively slowly, it will still be expensive. .

That is, for example, as shown in FIG.
), the output of the angular velocity sensor (11) is supplied to a low-pass filter (l8), and this filter (18) cuts off the high-frequency components and extracts only the slowly fluctuating drift components. Store the ingredients in memory (19). Then, the output of the memory (19) is converted to the subtracter (1
7) and subtracts the drift component from the output of the memory (12) which stores the output of the angular velocity sensor (11) as it is. Then, the subtracted output is supplied to the integration circuit (21) as output data of the gyro device (10'). The other parts have the same structure as the circuit in the example shown in FIG.

With the configuration of the example in FIG. 4 as well, drift components are continuously detected and angular velocity data from which drift components are continuously removed can be obtained.

Furthermore, it goes without saying that the present invention is not limited to the above-mentioned embodiments, and can take various other configurations.

FIG. 2 is an explanatory diagram showing a conventional detection state.

(10) is a gyro device, (11) is an angular velocity sensor, (
l2)+(14) is a memory, (13) is a sample/hold circuit, (15) is a stop detection circuit, and (16) is an approximate estimation circuit.

[Effects of the Invention] According to the gyro device of the present invention, accurate angular velocity data can be detected using a relatively inexpensive angular velocity sensor that generates many drift components, and there is an advantage that accurate position detection can be performed. .

[Brief explanation of drawings]

Claims (1)

[Claims] A gyro device that detects the moving direction of a moving body based on the output of an angular velocity sensor, which approximately detects a drift component of the angular velocity sensor as continuous data, and uses the drift component as continuous data. A gyro device that obtains angular velocity data by subtracting it from the output.