JPS63286708A - Navigator for vehicle - Google Patents

Abstract

PURPOSE:To calculate an exact running distance of a vehicle, irrespective of a state of the road surface, by detecting a disturbance of a pulse period from a pulse generating means, and estimating an error of the running distance. CONSTITUTION:A pulse from a pulse generating means 12 in case a vehicle is running on a gravel road, an uneven road, a frozen road, etc. becomes a pulse having no regularity. In this case, a disturbance of a pulse period is detected 14, outputted to a distance error estimating means 15, and by this information, whether an error of a running distance is large or small, and a range of the error are estimated 15. Subsequently, a present position calculating means 16 calculates 16 the present position of the vehicle by an advance direction of the vehicle from a direction detecting means 11, the number of pulses from a pulse counter 13, and an error of the running distance estimated by the distance error estimating means 15 of the diameter of a wheel. Also, an on-map position determining means 17 determines a position on a map of the vehicle by information from the present position calculating means 16, and map information 18, in accordance with the error of the running distance, which has been estimated 15, and the map information is displayed 20 through a display control means 19.

Description

[Detailed description of the invention] Industrial applications The present invention relates to military navigators.

2. Description of the Related Art Conventionally, in this type of car navigator, as shown in FIG. 1
The pulse counter 3 counts the number of pulses from the pulse generating means 2.

In the arithmetic and control unit, the current position calculation means 4 calculates the current position of the vehicle based on the traveling direction of the vehicle from the direction detection means 1, the number of pulses from the pulse counter 3, and the wheel diameter, that is, the distance traveled. The position determination means 5 determines the position of the vehicle on the map based on the information from the current position calculation means 4 and the map information stored in the auxiliary storage means 6, and the display control means 7 determines the position information of the vehicle on the map. The map information stored in the auxiliary storage means 6 is displayed on the display means 8 in a superimposed manner.

Problems to be Solved by the Invention However, in the conventional military navigator described above, since the current position calculation means 4 calculates the distance traveled by the vehicle based on the number of pulses from the pulse counter 3 and the wheel diameter, When the wheels slip or spin while driving on a road, etc., there is a problem that it is not possible to accurately calculate the distance traveled by the vehicle.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a military navigator that can accurately calculate the distance traveled by a vehicle regardless of road surface conditions.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention detects a disturbance in the period of the pulse from the pulse generating means, and detects this period! The present invention is characterized in that an error in the running distance is estimated due to JJ disturbance, and the running distance is corrected based on this error.

Function The present invention has the above-mentioned configuration (Secondly, when the wheels slip or spin when driving on a gravel road or icy road, etc., in order to correct the error in the traveling distance, the vehicle is operated regardless of the condition of the road surface. Accurate mileage can be calculated.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic block diagram showing one embodiment of a car navigator according to the present invention, FIG. 2 is a waveform diagram of main signals when no period disturbance occurs in the military navigator of FIG. 1, and FIG.
The figure is a waveform diagram of main signals when a period disturbance occurs in the car navigator of FIG. 1.

In FIG. 1, reference numeral 11 indicates direction detection means for detecting the traveling direction of the vehicle, and reference numeral 12 indicates pulse generation means for generating one pulse per unit angular rotation of the wheel, the number of pulses corresponding to the travel distance. , 13 is a pulse counter for counting the number of pulses from the pulse generating means 12, and 14 is a pulse-period disturbance detecting means for detecting a disturbance in the frequency of the pulses generated by the pulse generating means 12.These direction detecting means 11, pulse generating means 12, pulse counter 13, and pulse period disturbance detecting means 14 constitute a sensor section of a military navigator.

15 is a distance error estimating means for estimating an error in the traveling distance based on the information on pulse frequency disturbance from the pulse period disturbance detecting means 14; 16 is a means for estimating the traveling distance error from the information on the traveling direction of the vehicle from the direction detecting means 11 and a pulse counter; Current position calculation means calculates the current position of the vehicle based on the number of pulses from 13, the wheel diameter, and the mileage error information from distance error estimation means 15, that is, the distance traveled. , map information stored in the auxiliary storage means 18 (map position determination means 19 for determining the position of the vehicle on the map) It is a display control means that superimposes and displays map information on the display means 20, and these distance error estimation means 15, current position calculation means 16, map position determination means 17, and display control means 19 function as the calculation control section of the military navigator. This arithmetic control section is composed of a microcomputer.

The auxiliary storage means 18 is a floppy disk, an optical disk,
The display means 20 is composed of a semiconductor memory, etc.
It consists of a T display, a liquid crystal display, etc.

Next, the operation of the above configuration (two related embodiments) will be explained with reference to FIGS. 2 and 3.

In the sensor section, a direction detecting means 11 detects the traveling direction of the vehicle, a pulse generating means 12 generates one pulse for each unit angle rotation of the wheel, the number of pulses corresponding to the traveling distance, and a pulse counter. 13 counts the number of pulses from the pulse generating means 12.

Here, when the wheels are running on the road surface without slipping, the pulses from the pulse generating means 12 are regular pulses as shown in FIG.

That is, in the case of constant speed running, as shown in Fig. 2 (A) (-), each pulse interval tn+1, jns jn+1 becomes equal interval (==α) and repeats a constant cycle, and in the case of accelerated running, , as shown in Fig. 2 (B), the pulse interval becomes jn = tn - 1 - α (1), and the period gradually becomes shorter, and in the case of deceleration running, as shown in Fig. 2 (C). Thus, the pulse interval becomes jn=tn-1+α(1), and the period gradually becomes longer.

Therefore, the pulse generating means 12 for a predetermined time interval To
When detecting pulses from the vehicle, if the wheels are running on the road without slipping, there will be no sudden change in the pulse cycle.

In this case, the pulse period disturbance detection means 14 transmits information that the pulses have regularity to the distance error estimation means 1 of the arithmetic and control unit.
5, and the distance error estimating means 15 estimates the distance error to be "0" based on this information (2).

On the other hand, when the vehicle is traveling on a gravel road, uneven road, frozen road, etc., the pulses from the pulse generating means 12 are irregular as shown in FIG.

That is, when driving on a gravel road, each pulse interval tn-1, t of a predetermined time interval TO is
n, tn+1 become irregular and the period is disturbed from beginning to end.

If the wheels are slipping when driving on an icy road, the rotation of the wheels will be less than the actual distance traveled, and as shown in FIG.
+1 is longer than other pulse intervals j n-1, etc.

Also, if the wheels are spinning idle due to driving on a bumpy road, the rotation of the wheels will be greater than the actual distance traveled, as shown in Figure 3 (
As shown in (2) pulse interval Ln- of time interval T2
1, tn is the other pulse interval t. It will be shorter than +1 mag.

In this case, the pulse period disturbance detection means 14 detects the disturbance of the pulse period and outputs it to the distance error estimation means 15, and the distance error estimation means 15 uses this information to determine the size of the error in the traveling distance and the range of the error. presume.

In this estimation method, for example, as shown in FIG.
-1, jn+1~) or the size of the disturbance jn tl
Sjn+l ji, however, 1=-...n-1, n
+1...), it is detected that the rotation is small, and the range of the error is estimated.

The current position calculating means 16 calculates the current position of the vehicle based on the traveling direction of the vehicle from the direction detecting means 11, the number of pulses from the pulse counter 13, the wheel diameter, and the error in the traveling distance estimated by the distance error estimating means 15. Calculate the position.

The map position determining means 17 determines the position of the vehicle on the map based on the information from the current position calculating means 16 and the map information stored in the auxiliary storage means 18 according to the error in the mileage estimated by the distance error estimating means 15. The display control means 19 determines the position of the vehicle on the map and the auxiliary storage means 1.
The map information stored in 8 is displayed on display means 20 in a superimposed manner.

Therefore, according to the above embodiment, if the wheels slip or spin while driving on a gravel road or an icy road, and the count number of the pulse counter 13 does not correspond to the actual distance traveled, the pulse period may be disturbed. The detection means 14 and the distance error estimation means 15 can correct the detection error of the traveling distance.

Further, the map position determining means 17 is configured to include the distance error estimating means 1
Since the current position of the vehicle on the map is determined according to the error in the travel distance estimated by 5 (=, it is possible to improve the matching accuracy of image information.

DETAILED DESCRIPTION OF THE INVENTION As described above, the present invention provides a pulse generating means! The system is configured to detect disturbances in the cycle of the pulses of J), estimate the error in travel distance based on this disturbance in the cycle, and correct the travel distance based on this error, so it is possible to avoid driving on gravel roads, icy roads, etc. It is possible to accurately calculate the distance traveled by the vehicle even when the wheels slip or spin.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram showing an embodiment of a car navigator according to the present invention, FIG. 2 is a waveform diagram of main signals when no period disturbance occurs in the car navigator of FIG. 1, and FIG. This figure is a waveform diagram of main signals when a period disturbance occurs in the Ichikawa navigator shown in FIG. 1, and FIG. 4 is a schematic block diagram showing a conventional car navigator. 11...Direction detection means, 12...Pulse generation means,
13...Pulse counter, 14...Pulse cycle disturbance detection means, 15...Distance error estimation means, 16...Current position calculation means, 17...Map position determination means, 18
... Auxiliary storage means, 19... Display control means, 20.
...Display means. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2 (a) Equal fugue run (tn-anti) (■]) Accelerated run (tn = in-t -at(t))
(c) Deceleration running Untn-ked(t)) Figure 3

Claims (1)

[Claims] a pulse generating means for generating pulses in accordance with the rotation of the wheel; a counter for counting the pulses from the pulse generating means; a means for detecting a disturbance in the period of the pulse from the pulse generating means; A car navigator comprising means for estimating an error in travel distance due to turbulence, and means for calculating a travel distance of the vehicle from the count value of the counter and correcting the travel distance using the error estimated by the estimating means.