Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Automatic route guidance vehicle
Reexamination Certificate
2002-01-18
2004-06-15
Nguyen, Tan Q. (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Automatic route guidance vehicle
C701S213000, C318S587000, C340S437000
Reexamination Certificate
active
06751535
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a travel controlling apparatus of an unmanned vehicle which automatically travels on a preset traveling path in a mine, a stone quarry and the like.
2. Description of the Prior Art
Conventionally, as a traveling system of an unmanned vehicle automatically traveling on a preset traveling path, there has been well known a structure which employs both of a global positioning system navigation (hereinafter, refer to a GPS navigation) controlling an absolute position of the unmanned vehicle on the basis of a GPS receiver and an autonomous navigation detecting a traveling direction and a traveling distance of the unmanned vehicle so as to estimate and calculate a relative position and an azimuth on the basis of the absolute position by an inner angle sensor, thereby improving an accuracy of position measurement in accordance with a mutual complement between the both and traveling.
As the autonomous navigation, there have been known a dead reckoning navigation (a navigation of calculating a traveling distance by using a speed sensor and a moving distance sensor and estimating an azimuth by using a gyroscope and an earth magnetism sensor, thereby estimating the position and the azimuth of the vehicle), an inertial navigation (a navigation of estimating the position and the azimuth of the vehicle by using the gyroscope and an acceleration), and the like. Hereinafter, these navigation methods are totally called as an autonomy navigation.
FIG. 12
is a view describing a traveling system of an unmanned vehicle. In
FIG. 12
, a fixed base station
1
governs a control of an unmanned vehicle
10
, and is structured such as to transmit a traveling path data and a vehicle control govern command to the unmanned vehicle
10
via a control communication antenna
2
b
and receive a vehicle state signs
Further, the unmanned vehicle
10
has a position measuring portion and a travel controlling portion The position measuring portion calculates an absolute coordinate value of a present position of the vehicle itself on the basis of positional information received from a plurality of satellites
3
a
to
3
e
by the GPS receiver via the GPS antenna
12
a
(the GPS navigation). At this time, the position measuring portion calculates a relative position and an azimuth from the absolute coordinate position given by the GPS on the basis of the traveling direction and the traveling distance, and subsequently estimates and calculates the present position and the azimuth (the autonomy navigation). Further, after traveling for a predetermined GPS positioning sampling time, the present position and the azimuth given by the relative position and the azimuth are corrected on the basis of the absolute position newly measured by the GPS. Further, the travel controlling portion calculates a traveling direction on the basis of a result of comparison between the position and the azimuth (the traveling direction) of the preset traveling path, and the present position and azimuth, and controls a steering and a vehicle speed so as to travel at a predetermined speed in the traveling direction. The structure is made such as to guide and travel the unmanned vehicle by repeating the processes mentioned above.
The GPS navigation mentioned above has a disadvantage that a calculating time from a timing starting the positioning and a timing time interval outputting a communication time lag and the positioning data from the GPS receiver to a final position measuring portion are slower than the position calculating time in accordance with the autonomy navigation. Further, there has been known a problem that an accuracy of positioning is deteriorated and there is a case that the positioning can not be executed due to a receiving environment of the satellites
3
a
to
3
e
, that is, a receiving environment reason such as a midair viewing property whether or not a midair of the unmanned vehicle is in a state of capable of normally receiving the GPS due to a peripheral quay wall, a forest, a structure or the like, an arrangement of satellites, a multipass at a time of receiving a radio wave reflected from a peripheral reflection subject, and the like, and in the case of DGPS (so-called differential type GPS), for the reason that a compensated information communication from the fixed base station
1
delays due to various reasons such as a mountain, the quay wall, the forest, the structure, the radio wave environment and the like.
On the contrary, the autonomy navigation is employed for compensating the disadvantage, and since the relative position is calculated by calculating a traveling distance for a short time at every predetermined time, for example, on the basis of measured values of the speed sensor and the azimuth sensor, it is possible to position at real time. However, since sensor errors of the speed sensor, the azimuth sensor and the like are accumulated, whereby there is a problem that the accuracy of positioning is deteriorated, it is intended to maintain an accuracy of position by compensating at every predetermined time on the basis of the GPS navigation mentioned above.
However, in the traveling system of the unmanned vehicle in accordance with the conventional art, there is the following problems.
(1) In the GPS navigation, there is a case that the accuracy of positioning is deteriorated due to an aggravation of the satellite receiving environment or an aggravation of the environment for receiving the compensated data from the base station in the case of DGPS, or the positioning can not be executed. In this case, an accuracy of a present position and a present azimuth which are calculated on the basis of the absolute position in accordance with the GPS navigation and the relative position and azimuth in accordance with the autonomous navigation is deteriorated, or when traveling only in accordance with the autonomous navigation, the accuracy of the present position and the present azimuth is deteriorated due to an accumulation of the measured errors. Accordingly, since an agency of guiding the unwanted vehicle is reduced, the vehicle control is damaged.
(2) In the case that the speed sensor, the azimuth sensor and the like in connection to the autonomous navigation are out of order, when traveling only in accordance with the GPS navigation, the positioning data output time interval in accordance with the GPS navigation is slow as mentioned above, the interval between the measured absolute coordinate position is too long, and an accuracy of travel guiding is reduced. Further, the accuracy of travel guiding is reduced due to the matter that the accuracy of speed and the accuracy of azimuth are deteriorated at a time of a low speed in the case of only the GPS navigation, the matter that the accuracy of positioning position and azimuth) is deteriorated for the reason that the GPS antenna track (corresponding to the azimuth in accordance with the GPS) is different from a direction of attitude of the vehicle at a time of turning, and the like.
Further, when the accuracy of positioning (position and azimuth) is reduced due to the deterioration of the receiving environment and the communication environment of the GPS navigation at this time, the accuracy of travel guiding is further reduced. Accordingly, in the case of the trouble in which the autonomous navigation can not be executed, the vehicle control is damaged, and a working ratio of the unmanned vehicle is reduced.
However, there is strongly desired a traveling system having a high reliability in which it is possible to securely guide and travel even in the case mentioned above.
SUMMARY OF THE INVENTION
The present invention is made by paying attention to the problems mentioned above, and an object of the present invention is to provide a travel controlling apparatus of an unmanned vehicle which can maintain a high accuracy of travel guiding even in the case that an accuracy of positioning of a GPS navigation or an autonomous navigation is deteriorated and a state that a position
Komatsu Ltd.
Nguyen Tan Q.
Varndell & Varndell PLLC
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