JPS59218913A - System for detecting moving direction - Google Patents

Abstract

PURPOSE:To detect the moving direction of a moving body continuously and highly accurately by forming an angular speed sensor and an earth magnetism sensor and synthesizing the outputs of respective sensors with a proper ratio in accordance with conditions. CONSTITUTION:In the initial stage of the movement of a car at the time immediately after turning on respective power supplies to the angular sensor 1 and the earth magnetism sensor 4, the ratio of the sensor 4 is switched to 100% during the warming-up of the sensor 1 by variably changing constants A, B by a signal processing circuit 9 to detect the moving direction only by the sensor 4. After the completion of warming-up of the sensor 1 after passing the set time. the ratio of the sensor 1 is increased and the ratio of the sensor 4 is decreased in accordance with the moving distance, and at the time when the car runs several Km,the angle synthesizing ratio of both the sensors is switched to 50%. Then the ratio of the sensor 1 is continuously increased, and finally switched to 100%. Thus, the moving direction can be performed continuously and highly accurately even if disturbance is generated at the time of switching.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a movement direction detection method for detecting the movement direction of a moving body such as an automobile using an on-vehicle sensor.

Prior Art Recently, a direction detector detects changes in direction as the vehicle moves, and a distance detector detects the travel distance of the vehicle according to the vehicle speed, and from these detected values the current position of the vehicle on the travel route is determined. is calculated by calculation,
A driving route display device has been developed that provides guidance by displaying constantly changing current position information on a screen while comparing it with a road map.

Generally, the direction detector in this type of travel route display device is a rate-type gyroscope that detects the angular velocity of a one-time change in the direction of a moving object, or a gas rate sensor (a sensor that detects the displacement of the gas flow caused by a change in direction of the moving object). A rate sensor is used, such as a heat-sensitive device that detects the angular velocity at the time of forging.However, with such a rate sensor, the rise time when the power is turned on is The characteristics are not very good, and there is a disadvantage that it takes a certain amount of time to perform stable direction detection (in the case of a gas rate sensor, it takes a certain amount of time).

Further, as a direction detector, a geomagnetic sensor is used that senses the geomagnetism and detects the relative relationship (for example, angle) between the rotation of the horizontal component and the traveling direction of the traveling object. With a direction detector using a geomagnetic sensor, the current absolute direction is always known, so there is no accumulation of errors as in the case of using a rate sensor.
Although it has the advantage that direction detection can be performed immediately after dλ is turned on, it has the disadvantage that it is greatly affected by disturbances such as when passing through railroad crossings or railway bridges.

Therefore, in the past, a rate sensor and a geomagnetic sensor were installed together, and when the forest was turned on, the geomagnetic sensor detected the direction, and the rate sensor started up from the moment the power was turned on! At the time of stabilization after 11 hours have elapsed, the direction detection is switched to the rate sensor, so that subsequent direction detection can be performed without being affected by disturbances.

However, when taking such measures, if the geomagnetic sensor is subject to disturbance at the time of switching from the geomagnetic sensor to the rate sensor, the current position of the moving object to be moved out will be determined based on the direction of movement detected at that time. Continuity will be lost.

In addition, even if the rate sensor is in a stable state after its start-up v, it is undeniable that drift occurs due to the driving of the car. Therefore, in the long run, the drift value is accumulated and the direction detection is affected by a large amount of A. There is a problem in that it causes a difference.

Purpose The present invention has been made in consideration of the above points, and a rate sensor ν and a geomagnetic sensor are installed together, and the outputs of each sensor are moved by combining them at an appropriate ratio according to the situation. The object of the present invention is to provide a hybrid-type movement direction detection method that enables continuous and highly accurate detection of the movement direction of a body.

composition An embodiment of the present invention will be described in detail below.

In the moving direction detection method according to the present invention, a rate sensor and a tllJll upper are provided together, and the short-time signal of the rate sensor and the long-term signal of the geomagnetic sensor are combined so that the ratio of the two is variable. By taking measures to optimally switch the ratio of angular composition according to the movement status of the moving object, the moving direction can always be detected with the highest accuracy.

The figure shows an example of a configuration for concretely implementing the moving direction detection method according to the present invention. A-D sampling the signal
A converter 3, a geomagnetic sensor 4, a distance sensor 5 that generates a pulse signal for each unit distance traveled by the vehicle, a waveform shaping circuit 6 that shapes the waveform of the pulse output, and a count of the waveform-shaped pulse signal. Mileage counting circuit 7
, a frequency detection circuit 8 that detects the output frequency of the waveform shaping circuit 6, and the A-D converter 3. The signal processing circuit 9 is comprised of a microcomputer that performs predetermined calculations based on the outputs of the mileage counting circuit 7 and the frequency detection circuit 8.

In this structure, when the car is running, the rate sensor l continuously detects the angular velocity ω of the car as it changes in one direction, and after the detection signal is amplified by the rate amplifier 2, Unit time Δ with D converter 3
It is sampled every t and converted into a signal of the declination angle Δt (Δθ - ω・Δt) according to the direction of travel of the car, and the declination signal Δθ is given to the signal processing circuit 9. At the same time, the geomagnetic sensor Relative angle θ between the direction of the horizontal component of the geomagnetism detected by 4 and the direction of travel of the car
The FG signal is given to the signal processing circuit 9. Further, a pulse signal P output from the distance sensor 5 according to the unit mileage of the car is sent to the mileage counting circuit 7 through the waveform shaping circuit 6, and the distance signal counted there is sent to the signal processing circuit 9. At the same time, the frequency detection circuit 8 detects the output frequency of the pulse signal P, and the detection signal f is provided to the signal processing circuit 9.

Therefore, in the present invention, first, the signal processing circuit 9 detects that the automobile has traveled a preset unit distance based on the distance signal sent from the mileage counting circuit 7. Arithmetic processing is performed to synthesize the angle signals respectively detected by the rate sensor 1 and the geomagnetic sensor 4 each time the vehicle travels the unit distance. That is, first, the declination signal Δθ from the rate sensor 1 is added to the final output θ0tlT up to that point.

θOUT = θOUT + Δθ ・・・・・・(1
) As it is, the moving direction of the vehicle can only be detected by the rate sensor 1 system. Next, each time the car travels a unit distance, one angle word θ9 is read from the geomagnetic sensor 4, and the difference Δθ from the final output θ'OUT at that time is
, find.

Δθ"0FG-〇'OUT ・・・・・・(
2) Add a correction coefficient (A"B-
After subtracting the correction angle Δθ2 by .tnsJ, the correction angle 702 is subtracted from the final output θ'0LIT to obtain the angle-synthesized final output θ[7UT.

Δθ = (A+B ” tns ) ΔθI ”'
...(3) θSUT ”' θ5UT −Δθ
2 ・・・・・・(4) Correction coefficient (An-B-tn,) l'E is the one that has a maximum of 1, 5T variable constant% for A and H, tn8 is the time of non-stop driving of the car It is a count value. In addition, in the signal processing circuit 9, the frequency detection circuit 8 detects whether the automobile is in a stopped state or in a running state depending on whether the frequency detection signal f sent is zero 71' or not.
When the vehicle is in a running state, the regular running time is counted to obtain tns.

Therefore, when composing the angle signals respectively detected by the rate sensor 1 and the geomagnetic sensor 4, the ratio of the angular composition can be controlled by changing the constants of A and B according to the moving situation of the vehicle. You will be able to change it at will. The constants A and B are determined by calculation so that when the rate sensor 1 and the geomagnetic sensor 4 have the same detection accuracy, they have the same ratio.

Specifically, at the beginning of the vehicle's movement after the rate sensor l and the geomagnetic sensor 4 are powered on iM, the mass rate sensor l is warmed up by variable control of the constants A and H by the signal processing circuit 9 & During the process, the rate of the geomagnetic sensor 4σ is set to 100%, and the movement direction is detected only by the geomagnetic sensor 4. Then, after the warm-up of the rate sensor 1 is completed after the set time has elapsed, the rate sensor is gradually detected as the moving distance progresses. As the ratio of l is increased, the ratio of the geomagnetic sensor 4 is decreased, so that when the car has traveled several kilometers, the ratio of the angle composition of both becomes 50% each, and then the ratio of the rate sensor l is increased. Then, the ratio is finally changed to 100-. Therefore, by adopting such a control means, it is possible to smoothly switch from the V geomagnetic sensor 4 to the rate set/sl, and even if a geomagnetic disturbance occurs at the time of the switch, continuity is not lost. Therefore, the direction of movement can be detected with high precision.

Further, the signal processing circuit 9 detects that the frequency signal f sent from the frequency detection circuit 8 becomes zero and detects that the F car has stopped.
The offset adjustment of the rate sensor 1 is performed using the declination signal Δθ sent from the sensor as a drift value.

At that time, as the non-stop driving time of the car becomes longer,
As the offset interval of the rate sensor 1 becomes longer, the accumulated error of the rate sensor l during that period becomes a problem, but in the present invention, as is clear from the relationship between the third and fourth equations, the number of cars in the row is The non-stop running time tns is counted, and in proportion to the time t0, that is, the unadjusted offset time of the rate sensor l, the ratio of the rate sensor l during angle synthesis is decreased, and the ratio of the block magnetic sensor 4 is increased. Measures are taken to eliminate the influence of the drift of the rate sensor l.

Note that the signal processing circuit 9 is used as the driving route display device.
0 function is extended, and the two-dimensional coordinates of The current position of the vehicle is determined moment by moment, and the data of the determined and ever-changing position is sequentially stored in the image memory. It will be displayed.

As described above, in the moving direction detection method according to the present invention, a sensor for detecting the moving direction of one moving body and a geomagnetic sensor are installed together, and the detected angle by the rate sensor and the detected angle by the geomagnetic sensor are weighted by a correction coefficient. By changing the correction coefficient depending on the movement status of the moving object, the ratio of angular synthesis can be switched to the optimum ratio, and both sensors always provide the best It has the excellent advantage of being able to detect the direction of a moving object with an accuracy of .

[Brief explanation of the drawing]

The figure is a block diagram showing a configuration example for specifically implementing the movement direction detection method according to the present invention. l...Rate sensor 2...Rate amplifier 3...
・A-D...Converter 4...Geomagnetic sensor 5.
・・Distance sensor 6・Waveform shaping circuit 7・Kt counting circuit for running 8・Frequency detection circuit 9・Signal processing circuit Applicant's agent Sei Karasui Procedural Amendment June 27, 1988 Day 1, Indication of the case 1982 Patent Application No. 094528 2, Name of the invention Movement direction detection method 3, Person making the amendment Relationship to the case Patent applicant 6-27-8-4, Jingumae, Shibuya-ku, Tokyo, Agent Kannai Capital Building 6F, 2-25 Benten-dori, Naka-ku, Yokohama, Kanagawa Prefecture, 231 Japan, Showa Year, Month, Day 8, Contents of Amendment (1) The scope of claims in the specification is amended as follows. [Claim 1: An angular velocity sensor and a geomagnetic sensor are provided as sensors for detecting the moving direction of a moving body, and the angle detected by the angular velocity sensor and the angle detected by the geomagnetic sensor are weighted by a correction coefficient i. A moving direction detection method that uses a method of compositing. 2. The moving direction detection method according to item 1 above, characterized in that a variable constant whose setting can be changed is used as the correction coefficient. 3. The moving direction detection method according to item 1 above, characterized in that the correction coefficient is based on the non-stop running time of the moving body. (2) In the description of the detailed description of the invention and the brief description of the drawings in the specification, please correct the word "rate sensor" to "angular velocity sensor" in the following places, page 2, line 19 and page 2. 20th line, 10th line on page 3, 16th line, 18th to 19th lines, and 19th to additional lines, 4th line on page 4. 8th line and 15th line, 5th page 2nd to 3rd line, 4th line and 12th line, 6th page 7th line, 7th page 8th line, 10th to 3rd line 11th line and 14th line,
8th negative 16th line, 9th negative 1st line, 5th line, 8th line. 11th line, 12jj 1st O line and 20th line,
fPjlO page 7th line, 8th line, 11th line, 12th line
jj 1st O line, 17th to 18th line and 19th line
11th line, 16th line, 2nd page, 9th line (3) 7th negative final line, "Δθ" is corrected to "Δθ,". (4) In the same No. 12jj, 1st O line, "A-D...converter" is corrected to "rA-D converter". 71-

Claims (1)

[Claims] 1. A rate sensor and a geomagnetic sensor are provided as sensors for detecting the moving direction of a moving object, and the angle detected by the rate sensor and the angle detected by the geomagnetic sensor are weighted by a correction coefficient. A moving direction detection method that uses a method of compositing. 2. The moving direction detection method according to item 1 above, characterized in that the correction coefficient is a variable constant whose setting can be changed. 3. The moving direction detection method according to item 1 above, characterized in that the correction coefficient is based on the non-stop running time of the moving object.