CA2222124A1 - Device for detecting moving body deviating from course - Google Patents
Device for detecting moving body deviating from course Download PDFInfo
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- CA2222124A1 CA2222124A1 CA002222124A CA2222124A CA2222124A1 CA 2222124 A1 CA2222124 A1 CA 2222124A1 CA 002222124 A CA002222124 A CA 002222124A CA 2222124 A CA2222124 A CA 2222124A CA 2222124 A1 CA2222124 A1 CA 2222124A1
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- 238000005259 measurement Methods 0.000 claims description 25
- 238000001514 detection method Methods 0.000 claims description 14
- 238000004364 calculation method Methods 0.000 description 13
- 238000000034 method Methods 0.000 description 13
- 238000012937 correction Methods 0.000 description 12
- 230000000694 effects Effects 0.000 description 10
- 238000005516 engineering process Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 6
- 230000001186 cumulative effect Effects 0.000 description 5
- 239000002184 metal Substances 0.000 description 3
- 238000013459 approach Methods 0.000 description 2
- 238000013500 data storage Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 235000004443 Ricinus communis Nutrition 0.000 description 1
- 240000000528 Ricinus communis Species 0.000 description 1
- 230000002146 bilateral effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D1/00—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
- G05D1/02—Control of position or course in two dimensions
- G05D1/021—Control of position or course in two dimensions specially adapted to land vehicles
- G05D1/0231—Control of position or course in two dimensions specially adapted to land vehicles using optical position detecting means
- G05D1/0234—Control of position or course in two dimensions specially adapted to land vehicles using optical position detecting means using optical markers or beacons
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- Engineering & Computer Science (AREA)
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- Aviation & Aerospace Engineering (AREA)
- Radar, Positioning & Navigation (AREA)
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- General Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)
Abstract
Traveling paths over an entire traveling area are arbitrarily determined and can be flexibly changed. Traveling paths in the traveling area (20) where a moving body is to travel are arranged beforehand. For example, the marks adjacent to one another vertically and horizontally are rotated by 90~ and the marks adjacent to one another in oblique directions are inclined at the same angle. Therefore, when arbitrary predetermined traveling paths (A, B) in the predetermined traveling area (20) are selected and the moving body travels along the paths (A, B), line segment crossing detectors mounted on the moving body detect crossing all line segments which constitute predetermined passing marks corresponding to the paths (A, B). In this manner, it is possible to detect deviation from the paths (A, B). Also, even if some of more than two line segment crossing detectors cannot detect crossing all the line segments which constitute predetermined passing marks (paths C, D), at least one line segment crossing detector can detect crossing all the line segments which constitute the predetermined passing marks (paths A, B), whereby it is possible to detect deviation from the course.
Description
DESCRIPTION
DEVICE FOR DETECTING MOVING BODY DEVIATING FROM COURSE
TECHNICAL FIELD
The present invention relates to a device for detecting that a moving body, such as an automated vehicle, is deviating from a predetermined course, and more particularly to an arrangement of marks for detecting deviation and sensors for detecting the marks.
BACKGROUND ART
Up to now, the method for guiding an automated vehicle along a predetermined traveling path to a destination was called dead reckoning of estimating the current position of the vehicle with a direction detector and a device for measuring length of travel, and automatically steering the vehicle through predetermined passing points on the predetermined path, instructed in advance. For example, the method to express the predetermined traveling path with a series of coordinate points, in the case of effecting steering by dead reckoning, was disclosed in Japanese Patent Application No. 60-120275 and is already known.
The disadvantage of dead reckoning is that slippage of the vehicle and irregularities of the road surface result in errors of the estimated position of the vehicle and the vehicle cannot correctly pass through the predetermined passing points.
CA 02222124 1997-11-2~
Here, in the case of traveling outdoors, it is possible to correct the shift position intermittently with GPS (global positioning system) or radiolocation, etc. This can resolve the problem of being unable to correctly pass through the predetermined passing point.
However, the disadvantage of GPS, etc., is that these systems cannot be used outdoors or underground. Consequently, there is need for a system which can make it possible for a vehicle to correctly pass through the predetermined passing points even indoors.
Therefore, with the object of resolving such issues at low cost, the inventors have invented various methods, and the applicant has applied for various patents, for methods wherein guidance marks (referred to as "marks" below), having line segments in a predetermined geometrical form, are established intermittently on the predetermined traveling path and provide means to correctly guide a vehicle along the predetermined traveling path.
For example, in Japanese Patent Application No. 59-213991, three line segments comprising metal plates, etc., are placed in the form of a Z and a plurality of these marks is established intermittently so that all of the line segments of these Z-shaped marks lie across a predetermined traveling path; the three line segments of the marks are detected in sequence by sensors placed on an automated vehicle during travel; the course deviation of the automated vehicle (the deviation of the actual mark passing position from the predetermined mark passing position) is found by a calculation CA 02222124 1997-11-2~
based on the detection timing and the geometrical relationship of the Z; and the estimated position of the automated vehicle is intermittently calibrated based on the course deviation found.
However, in this method where marks are arranged along a predetermined traveling path, there is no margin for selecting a traveling route and the automated vehicle can only travel along a single traveling route.
Therefore, in Japanese Patent Application No. 60-213916, in order to operate the automated vehicle on one traveling route selected from among a plurality of traveling routes, as shown in Figure 15, a plurality of Z-shaped marks are arranged in a state where the marks adjacent to one another vertically and horizontally are inclined at the same angle and the marks adjacent to one another in oblique directions are rotated by 90~, so as to be able to select one traveling route from among a plurality of predetermined traveling paths.
The way the marks are arranged, shown in Figure 15, it is possible to establish a plurality of predetermined traveling paths inside the lot wherein the marks are arranged, but a large number of predetermined traveling paths cannot be established.
For example, the path A' in Figure 15 passes through the marks, but the estimated position cannot be corrected using the marks through which the path passes because the path A' does not cross all line segments of the marks. Also, path B' and path C' do not cross all of the line segments of the marks, and so the estimated position cannot be corrected in these cases either.
Therefore, with the conventional method, it is clear that for a large number of predetermined traveling paths, the estimated position cannot be corrected using marks.
Specifically, the prior art cannot respond with flexibility to changes in the traveling route, because it is not possible to establish arbitrary predetermined traveling paths within the predetermined traveling area.
DISCLOSURE OF THE INVENTION
The present invention was made in view of the foregoing situation; it is an object of the present invention to make possible the establishment of arbitrary predetermined traveling paths throughout an entire traveling area and make possible a flexible response to changes in the traveling route.
This object is attained as follows.
Specifically, in a first invention of the present invention there is provided a device for detecting a moving body deviating from a course, in which predetermined passing marks through which a moving body passes are arranged intermittently on a predetermined traveling path, so that all line segments constituting marks comprising at least a first and a second line segments which are not parallel to each other, cross the predetermined traveling path; an actual position on the predetermined passing marks is detected by detecting, by means of a line segment crossing detector mounted on the moving body, the crossing of all line segments CA 02222124 1997-11-2~
constituting the predetermined passing marks during the traveling of the moving body; and a course deviation from the predetermined traveling path of the moving body is detected based on a predetermined passing position on the predetermined passing marks and the actual position on the predetermined passing marks which was detected, characterized in that:
a plurality of marks are respectively inclined and arranged in advance within a predetermined traveling area, so that, in the case where an arbitrary predetermined traveling path in the predetermined traveling area, through which the moving body must travel, is selected and the moving body is caused to travel along the arbitrary predetermined traveling path, the line segment crossing detector mounted on the moving body can detect the crossing of all line segments constituting the predetermined passing marks corresponding to the arbitrary predetermined traveling path.
With the constitution of the aforementioned first invention, marks are arranged in advance as shown in Figure 7, within a predetermined traveling area 20 through which the moving body must travel, in a state where the marks adjacent to one another vertically and horizontally are rotated by 90~
and the marks adjacent to one another in oblique directions are inclined at the same angle, for example. For this reason, when the arbitrary predetermined traveling paths A and B
within the predetermined traveling area 20 are selected and the moving body travels along the pertinent arbitrary predetermined traveling paths A and B, the crossing of all line segments constituting the predetermined passing marks CA 02222124 1997-11-2~
corresponding to the pertinent, arbitrary predetermined traveling paths A and B is detected with the line segment crossing detectors placed on the moving body. In this way, course deviation can be detected for an arbitrary predetermined traveling path.
Also, in a second invention of the present invention, a distance between two or more line segment crossing detectors is established so that at least one line segment crossing detector of the two or more line segment crossing detectors can detect the crossing of all line segments constituting the predetermined passing marks.
With the constitution of the aforementioned second invention, the course deviation can be detected with certainty for an arbitrary predetermined traveling path, because the crossing of all line segments constituting the predetermined passing marks is detected by at least one line segment crossing detector (paths A and B), even if the crossing of all line segments constituting the predetermined passing marks is not detected by a number of line segment crossing detectors from among two or more line segment crossing detectors (paths C and D).
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a view from above of the traveling area of an embodiment;
Figure 2 is a block diagram to show the constitution of the control system of an embodiment;
Figure 3 is a diagram to show the constitution of a side wheel drive vehicle of an embodiment;
Figure 4 is a diagram to show the constitution of a front wheel steered vehicle of an embodiment;
Figure 5 is a diagram to show the locus of a vehicle of an embodiment;
Figure 6 is an inclined view to show the constitution of the mark body of an embodiment;
Figure 7 is a view from above to show the locus through which a sensor passes inside the traveling area;
Figure 8 is a graph to show the relationship between the interval between a main sensor and auxiliary sensor, the detection interval, and the error count;
Figure 9 is a view from above to show loci of sensors when a vehicle is traveling at an angle through a traveling area;
Figure 10 is a view from above to show loci of sensors when a vehicle is traveling at an angle through a traveling area;
Figure 11 is a flow chart to show the processing procedure through the approach of a vehicle to a traveling area shown in Figure 1;
Figure 12 is a view from above to show the situation where the cumulative error, due to the dead reckoning method, increases along with the progress of the vehicle;
Figures 13(a)-13(e) are figures illustrating geometrical forms of the line segments constituting the mark body;
Figures 14(a)-14(c) are figures illustrating geometrical forms of the line segments constituting the mark body; and CA 02222124 1997-11-2~
Figure 15 is a view from above to show the conventional arrangement of mark bodies.
BEST MODE FOR CARRYING OUT THE INVENTION
Below, the mode for carrying out the device for detecting moving body deviating from course, relating to the present invention, is explained with reference to the figures.
Figure 1 is a view from above of the predetermined traveling area 20 through which an automated vehicle 1 (referred to as "vehicle" below), which is a moving body, is to travel, this traveling area 20 is covered with mark bodies 24, discussed below.
The mark bodies 24 (referred to below, appropriately, as "marks") are laid out in such a manner that the marks adjacent to one another vertically and horizontally are rotated by 90~
and the marks adjacent to one another in oblique directions are inclined at the same angle.
On the near side of the traveling area 20, the marks 40 and 41 are arranged in such a manner that a line extending from the reference axis of measurement 42 (in effect, the center line of the marks; the axis crossing all line segments constituting the marks at right angles) of marks 40 and 41, having the same constitution as marks 24, crosses the traveling area 20. Furthermore, the standby position 19 of the vehicle 1 is located on the near side of these marks 40 and 41. The vehicle 1 is halted facing the already aforementioned reference axis of measurement 42.
The vehicle 1 comprises a direction detector and a device CA 02222124 1997-11-2~
for measuring length of travel, calculates its current position using these detectors, and is automatically steered to travel on the predetermined traveling path. The technology for this automatic steering is the known technology relating to a previous application (Japanese Patent Application No. 60-120275) made by the applicant. A detailed explanation is not included since this technology is not directly related to the gist of the present invention.
Figure 2 is a diagram of the entire constitution of the control system of the vehicle 1.
Here, the vehicle 1 may be a side wheel drive vehicle as shown in Figure 3 or the front wheel steered vehicle as shown in Figure 4. This embodiment is explained presupposing the use of the side wheel drive vehicle as shown in Figure 3.
This side wheel drive vehicle 1 comprises a cylindrical car body 15, for example, as shown in Figure 3, on the side of that car body 15, side drive wheels 2 and 3 are placed on the same axis as the diameter of the circle. Also, castors 16F
and 16R are placed on the front and rear of the car body 15.
A main sensor 5, to detect the aforementioned mark bodies 24, 40, and 41 as discussed below, is mounted on the lower surface at the center point of the line segment connecting wheels 2 and 3, being the lower surface of the car body 15. Likewise, an auxiliary sensor 6 is placed on the line segment connecting the wheels 2 and 3, on the lower surface of the car body 15, as being separated from the main sensor 5 just by a distance d, discussed below.
As shown in Figure 2, encoders 2E and 3E are mounted on CA 02222124 1997-11-2~
the side wheels 2 and 3 of the vehicle 1; the encoders 2E and 3E measure the length of travel of the vehicle 1 by detecting the rotary position of the wheels 2 and 3. Specifically, the encoders 2E and 3E output pulse signals showing the length of travel; the counter 7 takes up the pulse signals as data for each side separately; and the count results of the counter 7 are output to both the mark detection section 8 and the dead recko~; ng calculation section 9.
Signals output from the main sensor 5 and auxiliary sensor 6 which show the crossing of line segments 23a, 23b, and 23c of the marks 24 (See Figure 6) are input to the mark detection section 8; meanwhile, the counter measurement value, showing the length of travel and which is output from the encoders 2E and 3E, is input to the mark detection section 8.
As a result, the travel distance, from the crossing of a line segment of the mark 24 (for example, line segment 23a) to the crossing of the next line segment 24b, and the travel distance, from the crossing of the line segment 24b to the crossing of the next line segment (for example 23c), are attained in the mark detection section 8. The difference between the actual passing position on the mark 24 and the central position (predetermined passing position) of the mark 24, in effect the course deviation for the predetermined traveling path, is detected based on these two travel distances and the geometrical form (Z) of the line segments of the mark 24.
Moreover, the calculation procedure applied can be that which was explained in detail in Japanese Patent Application CA 02222124 1997-11-2~
No. 60-287439. In this way, the actual passing position in each mark 24 is output from the mark detection section 8 in sequence for each passage through the marks 24.
In the dead reckoning calculation section 9, the serial current position of the vehicle 1 is estimated and calculated based on the revolutions of the side wheels 2 and 3 output from the counter 7; meanwhile the sequential current direction of the vehicle 1 is estimated and calculated based on the difference between the revolutions of the side wheels 2 and 3 output from the counter 7. The estimated and calculated values of these serial current positions and current directions of the vehicle 1 are output to the position calibration section 10.
In the position calibration section 10, the mark 24, for the correction of the currently estimated position, is selected based on these serial current positions and current directions input by the dead reckoning calculation section 9 and the stored contents of the mark arrangement information storage section 11. Then the angle at which to enter the traveling area with respect to the reference axis of measurement of the selected mark 24 is found from the information of the current direction; meanwhile, it is determined whether the correction of the estimated position, using the selected mark 24, can be trusted. As a result, in the case where it is judged that the correction of the estimated position using the selected mark 24 can be trusted, the position correction signal, which will correct the current estimated position, is output to the dead reckoning CA 02222124 1997-11-2~
calculation section 9 according to the actual position on the mark 24 output from the mark detection section 8, at the time when the crossing of the last line segment to be crossed in the mark 24 is detected.
Two past position correction signals output from the position calibration section 10 are stored in the angle correction section 12; the corrected position, corrected according to those two past position correction signals, and the estimated position immediately previous to the reception of the two past position correction signals are stored in the angle correction section 12.
Specifically, an error in the direction traveled by the vehicle 1 therebetween can be confirmed by comparing the change in two coordinate positions which were properly corrected and the change in two estimated coordinate positions. Then, the angle correction section 12 corrects the serial estimated direction of the vehicle 1 by outputting the directional error attained in this way to the dead reckoning calculation section 9.
In this way, in the dead reckoning calculation section 9, the current estimated position is corrected by the actual position on the mark 24 based on the position correction signals which were input, while the current estimated direction is corrected based on the directional error which was input.
The corrected position and corrected direction output from the dead reckoning calculation section 9 are output to the steering controller section 13. In the steering CA 02222124 1997-11-2~
controller section 13, steering control is effected based on a known point tracking technology. This point tracking technology is a steering control method which changes the target site on the predetermined traveling path sequentially as the vehicle 1 advances; steering control is effected as follows: the coordinate position data of the target site is read in sequence from the predetermined traveling sequence of points data storage section 14, wherein coordinate position data of each site on the predetermined traveling path to be traveled is stored; and orders for reaching this coordinate position of the target site, in effect the direction of progress (target steering angle) and the speed of progress (target speed), are output to the motor controller 4.
Moreover, if the vehicle 1 does not operate at a constant speed and is supposed to vary the operating speed according to the location, it is possible to have and to store a correspondence to information relating to the speed of the vehicle 1 in the case of aiming at a target site, for each target site in the predetermined traveling sequence of points data storage section 14.
The motor controller 4 outputs the revolution speed order to the motors 2M and 3M which independently drive the left and right wheels 2 and 3 respectively. Here, in the independent driving vehicle, the average of the rotational speeds of the side motors 2M and 3M determines the speed of the vehicle l;
and the difference between the rotational speeds of the side motors 2M and 3M determines the steering angle. Then, based on this type of relationship, the motor controller 4 outputs CA 02222124 1997-11-2~
orders for rotational speed corresponding to the target speed and target steering angle of the vehicle 1 to the side motors 2M and 3M.
Next, the structure of the mark body 24 constituting the travel area 20 is explained below.
Figure 6 is an inclined view to show the arrangement of the mark body 24. A mark pattern 22 is mounted on the upper surface of the base plate 21, so that the center 21a of the square base plate 21, with the length of one side being a, agrees with the center 22a of the mark pattern 22. The lateral width of this mark pattern 22 is a; the depth corresponding to the direction of progress of the vehicle 1 has a dimension of a or less; such was already disclosed in Japanese Patent Application 59-213991.
When the mark pattern 22 is mounted on the base plate 21, the upper edge 21b of the square base plate 21 is made parallel to the line segments 23a and 23c (two parallel line segments of the Z) of the mark pattern 22. Moreover, in the case of preparing the mark body 24, the line segments 23a-23c, which constitute the Z, may also be applied directly on the base plate 21, without the plate-shaped mark pattern 22 being mounted on the base plate 21. Moreover, line segments 23a-23c are constituted of materials (for example, metal if the sensors 5 and 6 are metal detectors) which can enable the detection of the pertinent line segments by sensors 5 and 60 As shown in Figure 7, the mark bodies 24 are arranged on the traveling area 20 in a specific pattern with the mark bodies 24 having two orientations.
CA 02222124 1997-11-2~
Measurement of the actual position on the mark body 24 is possible if sensors 5 and 6 can have loci (below referred to as "sensor loci") so as to cross the three line segments 23a-23c of the mark body 24. This aspect is already disclosed in Japanese Patent Application No. 59-213991. As already discussed for Figure 1, the reference axis of measurement is defined as the axis which becomes the reference of measurement for sensor loci (of course, this also crosses line segment 23b) passing through the center point of the mark body 24 and crossing two line segments 23a and 23c at right angles.
Here, the mark body 24-1 within the traveling area 20 is "placed normal" so that the reference axis of measurement 25 is vertically oriented. In this case, the measurement of the mark body 24 with the sensors 5 and 6 becomes possible if sensor loci are within at least a 45~ horizontal range with respect to the reference axis of measurement 25. The way of arranging these two line segments 23a and 23c in a vertical position is called the "Z" arrangement. Meanwhilè, the mark body 24-2 positioned above the mark body 24-1 is the Z
arrangement rotated 90~; the reference axis of measurement 26 is oriented in a sideways direction. This arrangement with a 90~ rotation is called an "N" arrangement.
Ultimately, as shown in Figure 7, the marks 24 within the traveling area 20 adjacent to a Z type mark 24 vertically and horizontally are all N type and the marks 24 adjacent to a Z
type mark 24 in oblique directions are all the Z type.
Likewise, the marks 24 adjacent to an N type mark 24 in the traveling area 20 vertically and horizontally are all Z type CA 02222124 1997-11-2~
and the marks 24 adjacent to an N type mark 24 in oblique directions are all the N type.
The marks 24 cover such a traveling area 20 in a uniform pattern wherein the marks 24 adjacent vertically and horizontally are rotated 90~ and the marks 24 adjacent in oblique directions are inclined at the same angle. Below, this pattern of arranging the marks 24 is called "interleaving."
In Figure 7, in the case where the sensor loci have the horizontal orientation called A, the actual position on the marks 24 can be measured at every other mark because the marks 24 in the N-type arrangement are arranged at every other position in a horizontal direction. Moreover, in the case where sensor loci pass vertically, measurement at every other position becomes possible in the same way due to the marks 23 in the Z-type arrangement placed at every other position in a vertical direction.
Also, in the case of the 45~ inclined sensor locus called B, the actual position on the marks 24 can be measured continuously because the marks 24 in the Z-type arrangement are arranged consecutively in the direction of a 45~ angle.
Moreover, in the case where sensor loci pass over the marks 24 in the N-type arrangement, arranged consecutively in an angled direction, continuous measurement becomes possible in the same way due to these marks 24 in the N-type arrangement.
As above, the predetermined traveling path of the vehicle 1 may be arbitrary paths, including paths A', B', and C' (See Figure 15) which could not be used before now.
CA 02222124 1997-11-2~
However, measurement becomes impossible if the sensor locus A agrees with the reference axis of measurement of the marks 24 in the N-type arrangement and does not cross all three line segments 23a-23c of the marks 24.
Consequently, in the case of sensor loci like the sensor locus C in Figure 7 which deviates widely from the reference axis of measurement, but is parallel to the sensor locus A, and passes through the seam between marks 24 located above and below, sensors 5 and 6 can only detect the end portions of the line segments 23a-23c because the sensor locus grazes the upper and lower ends of the N of the marks 24. Therefore, the signal output by the sensors 5 and 6 becomes weak and measurement becomes impossible. Moreover, measurement becsmes impossible in the same way, in the case where sensor loci pass along the seam between the marks 24 to the right and left.
Also, measurement bPCom~ impossible if, as the sensor loci B, the sensor loci form a 45~ angle (45~ or less) with the reference axis of measurement of the marks 24 in the Z-type arrangement, pass through the centers of the marks 24, and do not cross all three line segments 23a-23c of the marks 24.
Consequently, in the case of sensor loci like the sensor loci D which deviate widely from the center points of the marks 24, but are parallel to the sensor loci B, the sensor loci cannot cross all three of the line segments 23a-23c of the marks 24 (can only cross one or two of the line segments) and measurement becomes impossible.
Therefore, it is necessary that measurement definitely be CA 02222124 1997-11-2~
possible with one sensor (sensor loci A, B), even though measurement with the other sensor, among the two sensors 5 and 6, becomes impossible (sensor loci C, D). In this case, the establishment of the interval d between the two sensors 5 and 6 becomes important.
The turning center of the side wheel drive vehicle 1 of the embodiment is on the axle connecting the left and right driving wheels 2 and 3 as shown in Figure 3. Moreover, the turning center is external to the car body in the case of the vehicle turning and describing a large turning radius.
Therefore, in the case where the two sensors 5 and 6 are established on the axle connecting the left and right driving wheels 2 and 3 and separated just by the distance d, these two sensors 5 and 6 are separated just by distance d usually in a direction at right angles to the direction of progress of the vehicle 1 (See Figure 5).
Also, in the case of using the front wheel steered vehicle shown in Figure 4 as the vehicle 1, the two sensors 5 and 6 are established on the axle connecting the side rear wheels 17L and 17R which do not steer and are separated just by the distance d. In this case as well, the two sensors 5 and 6 are separated just by distance d usually in a direction at right angles to the direction of progress of the vehicle 1 (See Figure 5) because, when the vehicle 1 progress while it is steered, it is turned with the center being the turning center present on the axle connecting the side rear wheels 17L
and 17R which do not steer.
Figure 8 is a graph showing the results of a calculation CA 02222124 1997-11-2~
of the capacity for the main sensor 5 and auxiliary sensor 6 to detect the mark body 24. The horizontal axis of the graph is the interval d between the main sensor 5 and the auxiliary sensor 6; the length of one side of the square mark body 24 is 100%.
The left vertical axis of the graph is the interval (travel distance) wherein the main sensor 5 or auxiliary sensor 6 detects the mark body 24 concurrent with the progress of the vehicle 1; a maximum distance, a minimum distance, an average distance, and a standard deviation in a range of less than 1000% (in effect, the length corresponding to ten times the length of one side of the mark 24; the length of one side of the square mark body is 100%) are shown.
The right vertical axis of the graph shows a number (this is called the error count) in the case where the interval wherein the main sensor 5 or auxiliary sensor 6 detects the mark body 24 exceeds 1000%.
As clear from this graph, there is a bilateral symmetry relationship between the cases where the distance d between the main sensor 5 and the auxiliary sensor 6 is positive and is negative. It is understood that the error count reaches its m;n;mum when the distance d is +35%, +106%, and +177%.
Figure 9 is a figure to explain the reason why the error count reaches the minimum when the distance d is these specific values. All the sensor loci in Figure 9 are inclined only to 45~.
The sensor locus 30 shown with the solid line deviates greatly from the center point of the mark 24 in the same way CA 02222124 1997-11-2~
as the sensor locus D in Figure 7 (passing through the center point of the lower side of each mark body 24); therefore, the sensor locus cannot cross all three line segments 23a-23c of each mark 24 (can only cross one or two of the line segments) and as a result, the sensors cannot detect the marks 24.
Meanwhile, the sensor locus 31 or sensor locus 32 shown with the dotted line in the figure deviates only by 50~ of the distance (half the length of one side of the mark 24) from the sensor locus 30. Because the sensor locus 31 or sensor locus 32 passes through the center points of all the marks 24, the actual position on the mark 24 can be detected at all the marks 24.
Ultimately, the distance d between all the sensor loci (31, 32, ...) shown with the dotted lines in Figure 9 and the sensor locus 30 shown with the solid line can be expressed as follows:
d=(N+1/2) / ~ x100% (N is an integer) ... (1) According to the aforementioned formula (1), d-about 35 when N=0, d=about 106~ when N=1, and d=about 176% when N=2;
this coincides with the results of the calculation shown ln Figure 8.
Therefore, the mark 24 can definitely be measured with the other sensor in the case where the distance d between the main sensor 5 and the auxiliary sensor 6 bec~ -s the specific distance shown in the aforementioned formula (1) (having the relationship between the solid and dotted lines shown in Figure 9).
Figure 10 shows the situation wherein the main sensor 5 and auxiliary sensor 6 alternately measure the marks 24 in the case where the vehicle 1 travels at an angle. In Figure 10, the locus of the main sensor 5 is shown with the solid line 33 and the locus of the auxiliary sensor 6 is shown with the dotted line 34.
As shown in this figure, the main sensor 5 crosses the three line segments 23a-23c of the mark 24-3; at the time when passed through the last line segment 23a, the coordinate position of that site 35 is found through calculation. Next, the auxiliary sensor 6 intersects the three line segments 23a-23c of the mark 24-4; at the time when passed through the last line segment 23a, the coordinate position of that site 36 is found through calculation. In this way, the main sensor 5 and the auxiliary sensor 6 alternately measure the coordinate positions on the mark 24.
The arrangement in which the sensors 5 and 6 are mounted on is known; therefore, the serial position of the vehicle 1 can be calculated by determining the coordinate position on the mark 24 as noted above, in effect the coordinate positions of the sensors 5 and 6.
Figure 11 shows the procedure for the vehicle 1 standing by as shown in Figure 1, from the application of electric power to the approach to the traveling area 20.
Initially, the vehicle 1 is stopped at the standby position 19 (Step 101); power is applied to the vehicle 1 in this state (Step 102). At this stage, the vehicle l still CA 02222124 1997-11-2~
does not precisely confirm its own position and direction.
Next, the vehicle 1 starts to move slowly forward without changing its direction from the initial state (the direction of the reference axis of measurement 42 of the marks 40 and 41) (Step 103).
Next, the vehicle 1 passes the mark 40 directly before it. Because the orientation and central coordinate of the mark 40 are known, the vehicle 1 can measure the coordinate position of passing points on the mark 40 by passing the mark 40. In effect, at the time when the vehicle 1 passes the final line segment 23a of the mark 40, the current position P40 (x40, y40) of the vehicle 1 can be measured (Step 104).
However, at this time, the precise value of the direction of travel is still unclear.
The vehicle 1 continues to move straight forward without any changes; the passing coordinate position P41 (x41, y41) on the mark 41 can be measured at the time when the vehicle 1 passes the next mark 41. Because the passing coordinate position is determined at two points in this way, the direction of the vehicle 1 between these passing points can be found as the direction of a line connecting the two points.
The precise direction, in addition to its position, is determined in this way (Step 105). Consequently, after this stage, where the initial position and direction are determined, it becomes possible to calculate its serial position and direction with known dead reckoning technology.
Even after the vehicle 1 enters the traveling area 20 (Step 106), the serial position and direction within the traveling area 20 can be estimated and calculated.
The vehicle 1 travels along a predetermined traveling path L within the traveling area 20. At this time, the actual position of each of the predetermined passing marks 24-5, 24-6, 24-7 ..., on the predetermined traveling path L over which the vehicle 1 passes, are measured in sequence in the same way as the marks 40 and 41.
As a result, the estimated and calculated positions are corrected serially according to the actual positions on the mark measured in sequence and the vehicle 1 can travel precisely along the predetermined traveling path L.
Moreover, this embodiment is explained with the presupposition that the standby position 19 and the marks 40 and 41 used for the initial settings are external to the traveling area 20, but the standby position may also be established at a known position within the traveling area 20.
Also, the position and direction of the vehicle 1 remain the same as before the power was turned off in the case where the vehicle 1 is driven to the standby point, stopped temporarily and the power is cut, then the vehicle 1 is let stand at that position, the power is turned on once more, then the vehicle 1 is started. In such a case, the data from directly before the power is cut off can be used without any processing as the data for the initial position and direction when the power is turned on.
Figure 12 is a diagram to show the situation where the error in its estimated position increases with the progress of the vehicle 1, which estimates and calculates its position with the dead reckoning technology.
Specifically, even if the position of the vehicle 1 is accurately measured at the initial position, the range of error reaches a size corresponding to 18a when the vehicle 1 advances just by distance a. In effect, it is known that the vehicle 1 is within that error range 18a, but the precise position within the error range 18a cannot be specified. In the same way, the error range grows to 18b, 18c, 18d, and 18f when the traveling distance of the vehicle 1 extends to b, c, d, and f.
When the traveling distance is b, the error range 18b is sufficiently less than the area 24a of the mark body 24.
Therefore it is at least determined that the vehicle 1 is present on the mark body 24. Because the orientation and central position of the mark body 24 are known, the precise position on the mark 24 can be measured by the vehicle 1 passing the mark body 24 and detecting that all line segments were crossed; this being the case, the vehicle 1 can update its precise position through correction at that time.
However, the vehicle 1 fails to detect the mark 24 at any of distances a, b, c, and d and could just barely detect the mark 24 at distance f.
In this case, the error range 18f at distance f becomes much greater than an individual mark 24a; the mark detected here cannot ultimately be determined to be a particular mark.
In effect, the surrounding marks 24b, 24c, 24d, 24e, and 24f, in addition to the mark 24a, are all within the error range 18f. Therefore, so long as sensors 5 and 6 normally pass the ; CA 02222124 1997-11-2~
mark 24 and detect all three line segments, the precise position on that mark 24 can be calculated, but it is not determined which mark is passed. Consequently, in this case, it cannot be updated to the precise coordinate position of the vehicle 1; the vehicle 1 fails to reduce the cumulative error due to the dead reckoning technology.
Specifically, in the case where the vehicle 1 travels on the interleaved marks 24, it is necessary to detect the next mark 24 correctly while the error range of the cumulative error due to the dead reckoning technology is sufficiently less than the area of the mark bodies 24. Therefore, consideration is given whether there is any problem regarding this issue in practical application.
For example, when the side wheel drive vehicle 1, wherein the space between the wheels 2 and 3 on the right and left is 60 cm and the wheel diameter is 200 mm, travels directly forward for 3 m on a fairly irregular office floor, it has produced a cumulative position error of 1 cm. This means that the vehicle can travel for a distance of ten of the mark bodies 24 with a side length of 30 cm. Consequently, if it is possible to correctly detect the next mark body 24 during the travel for a distance of ten times the side length of the marks 24, since the cumulative error range at that site is sufficiently less than the dimensions of the mark bodies 24, it becomes clear whether a position was measured by passing over a mark body 24 laid in a particular position and direction. According to the above, it is thought that there is no problem in practical application.
CA 02222124 1997-11-2~
Moreover, in the embodiment, it is presupposed that the vehicle 1 has wheels on the sides, but it may also be a vehicle with a single wheel. The method for finding the current position and direction by changing the length of travel of one wheel and the steering angle of that wheel is already known according to Japanese Patent Application No. 61-151421.
Also, in the embodiment, the position and direction of the vehicle 1 is estimated based on the travel length of the wheels, but a known inertial navigation method to find the current position based on an accelerometer and gyro signal may also be applied.
Also, in the embodiment, the explanation presupposes the case of using two sensors, but a larger number of sensors may also be used. In this case, depending also on the method of arrangement, the traveling distance of the detection interval of the marks 24 can generally be shortened.
Also, in the embodiment, sensors 5 and 6 are placed on the axis connecting the side wheels, but placement in other locations is naturally also possible. In effect, in the case where the car body is rigid and does not change form, the sensor loci and locus of the center of the car body can be made to correspond by the addition of an operation for geometrical coordinate transformation.
Also, in the embodiment, as shown in Figure 1, square marks 24 are prepared as the elements; the traveling area 20 is formed with these square marks 24 providing coverage in sequence so as to leave no gaps. However, a square unit 27 of CA 02222124 1997-11-2~
a combination of four square marks 24 may be prepared, the traveling area 20 may also be formed with this square unit 27 providing coverage in sequence so as to leave no gaps.
Likewise, a square unit 28 which is a combination of nine square marks 24 or a square unit ... which is a combination of sixteen marks may be prepared; the traveling area 20 may also be formed with these square units 28 ... providing coverage in sequence so as to leave no gaps.
Also, the traveling area 20 may be formed by directly laying down the line segments 23a-23c, rather than laying the square mark bodies 24 to form the traveling area 20.
Also, in the embodiment, it is presupposed that the marks 24 comprise line segments in a Z (N) form, but the line segments may be in other geometrical forms as well. For example, as shown in Figures 13(a)-13(e) and Figures 14(a)-14(c), marks 50-57 having line segments in various geometrical forms, which already became known in Japanese Patent Application No. 60-108792 (Japanese Patent Publication No. 7-3339), may also be used. Essentially, an arbitrary configuration can be used if it is a geometrical form at least having two line segments which are not parallel to each other and with which the actual position on a mark can be detected with a line segment crossing detector.
Also, in the embodiment, the course deviation (deviation of predetermined passing position on a mark from the actual passing position) attained through the detection of marks is used to correct the position estimated by dead reckoning, but the present invention is not limited to this. The use of the course deviation attained is arbitrary.
As explained above, the present invention attains the marked effects that the predetermined traveling path can be established arbitrarily across the entire traveling area and it is possible to respond flexibly to changes in the traveling route.
INDUSTRIAL APPLICABILITY
The present invention may also be applied to manned vehicles as well as automated vehicles; additionally, an arbitrary structure may be applied as the structure of the moving body.
DEVICE FOR DETECTING MOVING BODY DEVIATING FROM COURSE
TECHNICAL FIELD
The present invention relates to a device for detecting that a moving body, such as an automated vehicle, is deviating from a predetermined course, and more particularly to an arrangement of marks for detecting deviation and sensors for detecting the marks.
BACKGROUND ART
Up to now, the method for guiding an automated vehicle along a predetermined traveling path to a destination was called dead reckoning of estimating the current position of the vehicle with a direction detector and a device for measuring length of travel, and automatically steering the vehicle through predetermined passing points on the predetermined path, instructed in advance. For example, the method to express the predetermined traveling path with a series of coordinate points, in the case of effecting steering by dead reckoning, was disclosed in Japanese Patent Application No. 60-120275 and is already known.
The disadvantage of dead reckoning is that slippage of the vehicle and irregularities of the road surface result in errors of the estimated position of the vehicle and the vehicle cannot correctly pass through the predetermined passing points.
CA 02222124 1997-11-2~
Here, in the case of traveling outdoors, it is possible to correct the shift position intermittently with GPS (global positioning system) or radiolocation, etc. This can resolve the problem of being unable to correctly pass through the predetermined passing point.
However, the disadvantage of GPS, etc., is that these systems cannot be used outdoors or underground. Consequently, there is need for a system which can make it possible for a vehicle to correctly pass through the predetermined passing points even indoors.
Therefore, with the object of resolving such issues at low cost, the inventors have invented various methods, and the applicant has applied for various patents, for methods wherein guidance marks (referred to as "marks" below), having line segments in a predetermined geometrical form, are established intermittently on the predetermined traveling path and provide means to correctly guide a vehicle along the predetermined traveling path.
For example, in Japanese Patent Application No. 59-213991, three line segments comprising metal plates, etc., are placed in the form of a Z and a plurality of these marks is established intermittently so that all of the line segments of these Z-shaped marks lie across a predetermined traveling path; the three line segments of the marks are detected in sequence by sensors placed on an automated vehicle during travel; the course deviation of the automated vehicle (the deviation of the actual mark passing position from the predetermined mark passing position) is found by a calculation CA 02222124 1997-11-2~
based on the detection timing and the geometrical relationship of the Z; and the estimated position of the automated vehicle is intermittently calibrated based on the course deviation found.
However, in this method where marks are arranged along a predetermined traveling path, there is no margin for selecting a traveling route and the automated vehicle can only travel along a single traveling route.
Therefore, in Japanese Patent Application No. 60-213916, in order to operate the automated vehicle on one traveling route selected from among a plurality of traveling routes, as shown in Figure 15, a plurality of Z-shaped marks are arranged in a state where the marks adjacent to one another vertically and horizontally are inclined at the same angle and the marks adjacent to one another in oblique directions are rotated by 90~, so as to be able to select one traveling route from among a plurality of predetermined traveling paths.
The way the marks are arranged, shown in Figure 15, it is possible to establish a plurality of predetermined traveling paths inside the lot wherein the marks are arranged, but a large number of predetermined traveling paths cannot be established.
For example, the path A' in Figure 15 passes through the marks, but the estimated position cannot be corrected using the marks through which the path passes because the path A' does not cross all line segments of the marks. Also, path B' and path C' do not cross all of the line segments of the marks, and so the estimated position cannot be corrected in these cases either.
Therefore, with the conventional method, it is clear that for a large number of predetermined traveling paths, the estimated position cannot be corrected using marks.
Specifically, the prior art cannot respond with flexibility to changes in the traveling route, because it is not possible to establish arbitrary predetermined traveling paths within the predetermined traveling area.
DISCLOSURE OF THE INVENTION
The present invention was made in view of the foregoing situation; it is an object of the present invention to make possible the establishment of arbitrary predetermined traveling paths throughout an entire traveling area and make possible a flexible response to changes in the traveling route.
This object is attained as follows.
Specifically, in a first invention of the present invention there is provided a device for detecting a moving body deviating from a course, in which predetermined passing marks through which a moving body passes are arranged intermittently on a predetermined traveling path, so that all line segments constituting marks comprising at least a first and a second line segments which are not parallel to each other, cross the predetermined traveling path; an actual position on the predetermined passing marks is detected by detecting, by means of a line segment crossing detector mounted on the moving body, the crossing of all line segments CA 02222124 1997-11-2~
constituting the predetermined passing marks during the traveling of the moving body; and a course deviation from the predetermined traveling path of the moving body is detected based on a predetermined passing position on the predetermined passing marks and the actual position on the predetermined passing marks which was detected, characterized in that:
a plurality of marks are respectively inclined and arranged in advance within a predetermined traveling area, so that, in the case where an arbitrary predetermined traveling path in the predetermined traveling area, through which the moving body must travel, is selected and the moving body is caused to travel along the arbitrary predetermined traveling path, the line segment crossing detector mounted on the moving body can detect the crossing of all line segments constituting the predetermined passing marks corresponding to the arbitrary predetermined traveling path.
With the constitution of the aforementioned first invention, marks are arranged in advance as shown in Figure 7, within a predetermined traveling area 20 through which the moving body must travel, in a state where the marks adjacent to one another vertically and horizontally are rotated by 90~
and the marks adjacent to one another in oblique directions are inclined at the same angle, for example. For this reason, when the arbitrary predetermined traveling paths A and B
within the predetermined traveling area 20 are selected and the moving body travels along the pertinent arbitrary predetermined traveling paths A and B, the crossing of all line segments constituting the predetermined passing marks CA 02222124 1997-11-2~
corresponding to the pertinent, arbitrary predetermined traveling paths A and B is detected with the line segment crossing detectors placed on the moving body. In this way, course deviation can be detected for an arbitrary predetermined traveling path.
Also, in a second invention of the present invention, a distance between two or more line segment crossing detectors is established so that at least one line segment crossing detector of the two or more line segment crossing detectors can detect the crossing of all line segments constituting the predetermined passing marks.
With the constitution of the aforementioned second invention, the course deviation can be detected with certainty for an arbitrary predetermined traveling path, because the crossing of all line segments constituting the predetermined passing marks is detected by at least one line segment crossing detector (paths A and B), even if the crossing of all line segments constituting the predetermined passing marks is not detected by a number of line segment crossing detectors from among two or more line segment crossing detectors (paths C and D).
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a view from above of the traveling area of an embodiment;
Figure 2 is a block diagram to show the constitution of the control system of an embodiment;
Figure 3 is a diagram to show the constitution of a side wheel drive vehicle of an embodiment;
Figure 4 is a diagram to show the constitution of a front wheel steered vehicle of an embodiment;
Figure 5 is a diagram to show the locus of a vehicle of an embodiment;
Figure 6 is an inclined view to show the constitution of the mark body of an embodiment;
Figure 7 is a view from above to show the locus through which a sensor passes inside the traveling area;
Figure 8 is a graph to show the relationship between the interval between a main sensor and auxiliary sensor, the detection interval, and the error count;
Figure 9 is a view from above to show loci of sensors when a vehicle is traveling at an angle through a traveling area;
Figure 10 is a view from above to show loci of sensors when a vehicle is traveling at an angle through a traveling area;
Figure 11 is a flow chart to show the processing procedure through the approach of a vehicle to a traveling area shown in Figure 1;
Figure 12 is a view from above to show the situation where the cumulative error, due to the dead reckoning method, increases along with the progress of the vehicle;
Figures 13(a)-13(e) are figures illustrating geometrical forms of the line segments constituting the mark body;
Figures 14(a)-14(c) are figures illustrating geometrical forms of the line segments constituting the mark body; and CA 02222124 1997-11-2~
Figure 15 is a view from above to show the conventional arrangement of mark bodies.
BEST MODE FOR CARRYING OUT THE INVENTION
Below, the mode for carrying out the device for detecting moving body deviating from course, relating to the present invention, is explained with reference to the figures.
Figure 1 is a view from above of the predetermined traveling area 20 through which an automated vehicle 1 (referred to as "vehicle" below), which is a moving body, is to travel, this traveling area 20 is covered with mark bodies 24, discussed below.
The mark bodies 24 (referred to below, appropriately, as "marks") are laid out in such a manner that the marks adjacent to one another vertically and horizontally are rotated by 90~
and the marks adjacent to one another in oblique directions are inclined at the same angle.
On the near side of the traveling area 20, the marks 40 and 41 are arranged in such a manner that a line extending from the reference axis of measurement 42 (in effect, the center line of the marks; the axis crossing all line segments constituting the marks at right angles) of marks 40 and 41, having the same constitution as marks 24, crosses the traveling area 20. Furthermore, the standby position 19 of the vehicle 1 is located on the near side of these marks 40 and 41. The vehicle 1 is halted facing the already aforementioned reference axis of measurement 42.
The vehicle 1 comprises a direction detector and a device CA 02222124 1997-11-2~
for measuring length of travel, calculates its current position using these detectors, and is automatically steered to travel on the predetermined traveling path. The technology for this automatic steering is the known technology relating to a previous application (Japanese Patent Application No. 60-120275) made by the applicant. A detailed explanation is not included since this technology is not directly related to the gist of the present invention.
Figure 2 is a diagram of the entire constitution of the control system of the vehicle 1.
Here, the vehicle 1 may be a side wheel drive vehicle as shown in Figure 3 or the front wheel steered vehicle as shown in Figure 4. This embodiment is explained presupposing the use of the side wheel drive vehicle as shown in Figure 3.
This side wheel drive vehicle 1 comprises a cylindrical car body 15, for example, as shown in Figure 3, on the side of that car body 15, side drive wheels 2 and 3 are placed on the same axis as the diameter of the circle. Also, castors 16F
and 16R are placed on the front and rear of the car body 15.
A main sensor 5, to detect the aforementioned mark bodies 24, 40, and 41 as discussed below, is mounted on the lower surface at the center point of the line segment connecting wheels 2 and 3, being the lower surface of the car body 15. Likewise, an auxiliary sensor 6 is placed on the line segment connecting the wheels 2 and 3, on the lower surface of the car body 15, as being separated from the main sensor 5 just by a distance d, discussed below.
As shown in Figure 2, encoders 2E and 3E are mounted on CA 02222124 1997-11-2~
the side wheels 2 and 3 of the vehicle 1; the encoders 2E and 3E measure the length of travel of the vehicle 1 by detecting the rotary position of the wheels 2 and 3. Specifically, the encoders 2E and 3E output pulse signals showing the length of travel; the counter 7 takes up the pulse signals as data for each side separately; and the count results of the counter 7 are output to both the mark detection section 8 and the dead recko~; ng calculation section 9.
Signals output from the main sensor 5 and auxiliary sensor 6 which show the crossing of line segments 23a, 23b, and 23c of the marks 24 (See Figure 6) are input to the mark detection section 8; meanwhile, the counter measurement value, showing the length of travel and which is output from the encoders 2E and 3E, is input to the mark detection section 8.
As a result, the travel distance, from the crossing of a line segment of the mark 24 (for example, line segment 23a) to the crossing of the next line segment 24b, and the travel distance, from the crossing of the line segment 24b to the crossing of the next line segment (for example 23c), are attained in the mark detection section 8. The difference between the actual passing position on the mark 24 and the central position (predetermined passing position) of the mark 24, in effect the course deviation for the predetermined traveling path, is detected based on these two travel distances and the geometrical form (Z) of the line segments of the mark 24.
Moreover, the calculation procedure applied can be that which was explained in detail in Japanese Patent Application CA 02222124 1997-11-2~
No. 60-287439. In this way, the actual passing position in each mark 24 is output from the mark detection section 8 in sequence for each passage through the marks 24.
In the dead reckoning calculation section 9, the serial current position of the vehicle 1 is estimated and calculated based on the revolutions of the side wheels 2 and 3 output from the counter 7; meanwhile the sequential current direction of the vehicle 1 is estimated and calculated based on the difference between the revolutions of the side wheels 2 and 3 output from the counter 7. The estimated and calculated values of these serial current positions and current directions of the vehicle 1 are output to the position calibration section 10.
In the position calibration section 10, the mark 24, for the correction of the currently estimated position, is selected based on these serial current positions and current directions input by the dead reckoning calculation section 9 and the stored contents of the mark arrangement information storage section 11. Then the angle at which to enter the traveling area with respect to the reference axis of measurement of the selected mark 24 is found from the information of the current direction; meanwhile, it is determined whether the correction of the estimated position, using the selected mark 24, can be trusted. As a result, in the case where it is judged that the correction of the estimated position using the selected mark 24 can be trusted, the position correction signal, which will correct the current estimated position, is output to the dead reckoning CA 02222124 1997-11-2~
calculation section 9 according to the actual position on the mark 24 output from the mark detection section 8, at the time when the crossing of the last line segment to be crossed in the mark 24 is detected.
Two past position correction signals output from the position calibration section 10 are stored in the angle correction section 12; the corrected position, corrected according to those two past position correction signals, and the estimated position immediately previous to the reception of the two past position correction signals are stored in the angle correction section 12.
Specifically, an error in the direction traveled by the vehicle 1 therebetween can be confirmed by comparing the change in two coordinate positions which were properly corrected and the change in two estimated coordinate positions. Then, the angle correction section 12 corrects the serial estimated direction of the vehicle 1 by outputting the directional error attained in this way to the dead reckoning calculation section 9.
In this way, in the dead reckoning calculation section 9, the current estimated position is corrected by the actual position on the mark 24 based on the position correction signals which were input, while the current estimated direction is corrected based on the directional error which was input.
The corrected position and corrected direction output from the dead reckoning calculation section 9 are output to the steering controller section 13. In the steering CA 02222124 1997-11-2~
controller section 13, steering control is effected based on a known point tracking technology. This point tracking technology is a steering control method which changes the target site on the predetermined traveling path sequentially as the vehicle 1 advances; steering control is effected as follows: the coordinate position data of the target site is read in sequence from the predetermined traveling sequence of points data storage section 14, wherein coordinate position data of each site on the predetermined traveling path to be traveled is stored; and orders for reaching this coordinate position of the target site, in effect the direction of progress (target steering angle) and the speed of progress (target speed), are output to the motor controller 4.
Moreover, if the vehicle 1 does not operate at a constant speed and is supposed to vary the operating speed according to the location, it is possible to have and to store a correspondence to information relating to the speed of the vehicle 1 in the case of aiming at a target site, for each target site in the predetermined traveling sequence of points data storage section 14.
The motor controller 4 outputs the revolution speed order to the motors 2M and 3M which independently drive the left and right wheels 2 and 3 respectively. Here, in the independent driving vehicle, the average of the rotational speeds of the side motors 2M and 3M determines the speed of the vehicle l;
and the difference between the rotational speeds of the side motors 2M and 3M determines the steering angle. Then, based on this type of relationship, the motor controller 4 outputs CA 02222124 1997-11-2~
orders for rotational speed corresponding to the target speed and target steering angle of the vehicle 1 to the side motors 2M and 3M.
Next, the structure of the mark body 24 constituting the travel area 20 is explained below.
Figure 6 is an inclined view to show the arrangement of the mark body 24. A mark pattern 22 is mounted on the upper surface of the base plate 21, so that the center 21a of the square base plate 21, with the length of one side being a, agrees with the center 22a of the mark pattern 22. The lateral width of this mark pattern 22 is a; the depth corresponding to the direction of progress of the vehicle 1 has a dimension of a or less; such was already disclosed in Japanese Patent Application 59-213991.
When the mark pattern 22 is mounted on the base plate 21, the upper edge 21b of the square base plate 21 is made parallel to the line segments 23a and 23c (two parallel line segments of the Z) of the mark pattern 22. Moreover, in the case of preparing the mark body 24, the line segments 23a-23c, which constitute the Z, may also be applied directly on the base plate 21, without the plate-shaped mark pattern 22 being mounted on the base plate 21. Moreover, line segments 23a-23c are constituted of materials (for example, metal if the sensors 5 and 6 are metal detectors) which can enable the detection of the pertinent line segments by sensors 5 and 60 As shown in Figure 7, the mark bodies 24 are arranged on the traveling area 20 in a specific pattern with the mark bodies 24 having two orientations.
CA 02222124 1997-11-2~
Measurement of the actual position on the mark body 24 is possible if sensors 5 and 6 can have loci (below referred to as "sensor loci") so as to cross the three line segments 23a-23c of the mark body 24. This aspect is already disclosed in Japanese Patent Application No. 59-213991. As already discussed for Figure 1, the reference axis of measurement is defined as the axis which becomes the reference of measurement for sensor loci (of course, this also crosses line segment 23b) passing through the center point of the mark body 24 and crossing two line segments 23a and 23c at right angles.
Here, the mark body 24-1 within the traveling area 20 is "placed normal" so that the reference axis of measurement 25 is vertically oriented. In this case, the measurement of the mark body 24 with the sensors 5 and 6 becomes possible if sensor loci are within at least a 45~ horizontal range with respect to the reference axis of measurement 25. The way of arranging these two line segments 23a and 23c in a vertical position is called the "Z" arrangement. Meanwhilè, the mark body 24-2 positioned above the mark body 24-1 is the Z
arrangement rotated 90~; the reference axis of measurement 26 is oriented in a sideways direction. This arrangement with a 90~ rotation is called an "N" arrangement.
Ultimately, as shown in Figure 7, the marks 24 within the traveling area 20 adjacent to a Z type mark 24 vertically and horizontally are all N type and the marks 24 adjacent to a Z
type mark 24 in oblique directions are all the Z type.
Likewise, the marks 24 adjacent to an N type mark 24 in the traveling area 20 vertically and horizontally are all Z type CA 02222124 1997-11-2~
and the marks 24 adjacent to an N type mark 24 in oblique directions are all the N type.
The marks 24 cover such a traveling area 20 in a uniform pattern wherein the marks 24 adjacent vertically and horizontally are rotated 90~ and the marks 24 adjacent in oblique directions are inclined at the same angle. Below, this pattern of arranging the marks 24 is called "interleaving."
In Figure 7, in the case where the sensor loci have the horizontal orientation called A, the actual position on the marks 24 can be measured at every other mark because the marks 24 in the N-type arrangement are arranged at every other position in a horizontal direction. Moreover, in the case where sensor loci pass vertically, measurement at every other position becomes possible in the same way due to the marks 23 in the Z-type arrangement placed at every other position in a vertical direction.
Also, in the case of the 45~ inclined sensor locus called B, the actual position on the marks 24 can be measured continuously because the marks 24 in the Z-type arrangement are arranged consecutively in the direction of a 45~ angle.
Moreover, in the case where sensor loci pass over the marks 24 in the N-type arrangement, arranged consecutively in an angled direction, continuous measurement becomes possible in the same way due to these marks 24 in the N-type arrangement.
As above, the predetermined traveling path of the vehicle 1 may be arbitrary paths, including paths A', B', and C' (See Figure 15) which could not be used before now.
CA 02222124 1997-11-2~
However, measurement becomes impossible if the sensor locus A agrees with the reference axis of measurement of the marks 24 in the N-type arrangement and does not cross all three line segments 23a-23c of the marks 24.
Consequently, in the case of sensor loci like the sensor locus C in Figure 7 which deviates widely from the reference axis of measurement, but is parallel to the sensor locus A, and passes through the seam between marks 24 located above and below, sensors 5 and 6 can only detect the end portions of the line segments 23a-23c because the sensor locus grazes the upper and lower ends of the N of the marks 24. Therefore, the signal output by the sensors 5 and 6 becomes weak and measurement becomes impossible. Moreover, measurement becsmes impossible in the same way, in the case where sensor loci pass along the seam between the marks 24 to the right and left.
Also, measurement bPCom~ impossible if, as the sensor loci B, the sensor loci form a 45~ angle (45~ or less) with the reference axis of measurement of the marks 24 in the Z-type arrangement, pass through the centers of the marks 24, and do not cross all three line segments 23a-23c of the marks 24.
Consequently, in the case of sensor loci like the sensor loci D which deviate widely from the center points of the marks 24, but are parallel to the sensor loci B, the sensor loci cannot cross all three of the line segments 23a-23c of the marks 24 (can only cross one or two of the line segments) and measurement becomes impossible.
Therefore, it is necessary that measurement definitely be CA 02222124 1997-11-2~
possible with one sensor (sensor loci A, B), even though measurement with the other sensor, among the two sensors 5 and 6, becomes impossible (sensor loci C, D). In this case, the establishment of the interval d between the two sensors 5 and 6 becomes important.
The turning center of the side wheel drive vehicle 1 of the embodiment is on the axle connecting the left and right driving wheels 2 and 3 as shown in Figure 3. Moreover, the turning center is external to the car body in the case of the vehicle turning and describing a large turning radius.
Therefore, in the case where the two sensors 5 and 6 are established on the axle connecting the left and right driving wheels 2 and 3 and separated just by the distance d, these two sensors 5 and 6 are separated just by distance d usually in a direction at right angles to the direction of progress of the vehicle 1 (See Figure 5).
Also, in the case of using the front wheel steered vehicle shown in Figure 4 as the vehicle 1, the two sensors 5 and 6 are established on the axle connecting the side rear wheels 17L and 17R which do not steer and are separated just by the distance d. In this case as well, the two sensors 5 and 6 are separated just by distance d usually in a direction at right angles to the direction of progress of the vehicle 1 (See Figure 5) because, when the vehicle 1 progress while it is steered, it is turned with the center being the turning center present on the axle connecting the side rear wheels 17L
and 17R which do not steer.
Figure 8 is a graph showing the results of a calculation CA 02222124 1997-11-2~
of the capacity for the main sensor 5 and auxiliary sensor 6 to detect the mark body 24. The horizontal axis of the graph is the interval d between the main sensor 5 and the auxiliary sensor 6; the length of one side of the square mark body 24 is 100%.
The left vertical axis of the graph is the interval (travel distance) wherein the main sensor 5 or auxiliary sensor 6 detects the mark body 24 concurrent with the progress of the vehicle 1; a maximum distance, a minimum distance, an average distance, and a standard deviation in a range of less than 1000% (in effect, the length corresponding to ten times the length of one side of the mark 24; the length of one side of the square mark body is 100%) are shown.
The right vertical axis of the graph shows a number (this is called the error count) in the case where the interval wherein the main sensor 5 or auxiliary sensor 6 detects the mark body 24 exceeds 1000%.
As clear from this graph, there is a bilateral symmetry relationship between the cases where the distance d between the main sensor 5 and the auxiliary sensor 6 is positive and is negative. It is understood that the error count reaches its m;n;mum when the distance d is +35%, +106%, and +177%.
Figure 9 is a figure to explain the reason why the error count reaches the minimum when the distance d is these specific values. All the sensor loci in Figure 9 are inclined only to 45~.
The sensor locus 30 shown with the solid line deviates greatly from the center point of the mark 24 in the same way CA 02222124 1997-11-2~
as the sensor locus D in Figure 7 (passing through the center point of the lower side of each mark body 24); therefore, the sensor locus cannot cross all three line segments 23a-23c of each mark 24 (can only cross one or two of the line segments) and as a result, the sensors cannot detect the marks 24.
Meanwhile, the sensor locus 31 or sensor locus 32 shown with the dotted line in the figure deviates only by 50~ of the distance (half the length of one side of the mark 24) from the sensor locus 30. Because the sensor locus 31 or sensor locus 32 passes through the center points of all the marks 24, the actual position on the mark 24 can be detected at all the marks 24.
Ultimately, the distance d between all the sensor loci (31, 32, ...) shown with the dotted lines in Figure 9 and the sensor locus 30 shown with the solid line can be expressed as follows:
d=(N+1/2) / ~ x100% (N is an integer) ... (1) According to the aforementioned formula (1), d-about 35 when N=0, d=about 106~ when N=1, and d=about 176% when N=2;
this coincides with the results of the calculation shown ln Figure 8.
Therefore, the mark 24 can definitely be measured with the other sensor in the case where the distance d between the main sensor 5 and the auxiliary sensor 6 bec~ -s the specific distance shown in the aforementioned formula (1) (having the relationship between the solid and dotted lines shown in Figure 9).
Figure 10 shows the situation wherein the main sensor 5 and auxiliary sensor 6 alternately measure the marks 24 in the case where the vehicle 1 travels at an angle. In Figure 10, the locus of the main sensor 5 is shown with the solid line 33 and the locus of the auxiliary sensor 6 is shown with the dotted line 34.
As shown in this figure, the main sensor 5 crosses the three line segments 23a-23c of the mark 24-3; at the time when passed through the last line segment 23a, the coordinate position of that site 35 is found through calculation. Next, the auxiliary sensor 6 intersects the three line segments 23a-23c of the mark 24-4; at the time when passed through the last line segment 23a, the coordinate position of that site 36 is found through calculation. In this way, the main sensor 5 and the auxiliary sensor 6 alternately measure the coordinate positions on the mark 24.
The arrangement in which the sensors 5 and 6 are mounted on is known; therefore, the serial position of the vehicle 1 can be calculated by determining the coordinate position on the mark 24 as noted above, in effect the coordinate positions of the sensors 5 and 6.
Figure 11 shows the procedure for the vehicle 1 standing by as shown in Figure 1, from the application of electric power to the approach to the traveling area 20.
Initially, the vehicle 1 is stopped at the standby position 19 (Step 101); power is applied to the vehicle 1 in this state (Step 102). At this stage, the vehicle l still CA 02222124 1997-11-2~
does not precisely confirm its own position and direction.
Next, the vehicle 1 starts to move slowly forward without changing its direction from the initial state (the direction of the reference axis of measurement 42 of the marks 40 and 41) (Step 103).
Next, the vehicle 1 passes the mark 40 directly before it. Because the orientation and central coordinate of the mark 40 are known, the vehicle 1 can measure the coordinate position of passing points on the mark 40 by passing the mark 40. In effect, at the time when the vehicle 1 passes the final line segment 23a of the mark 40, the current position P40 (x40, y40) of the vehicle 1 can be measured (Step 104).
However, at this time, the precise value of the direction of travel is still unclear.
The vehicle 1 continues to move straight forward without any changes; the passing coordinate position P41 (x41, y41) on the mark 41 can be measured at the time when the vehicle 1 passes the next mark 41. Because the passing coordinate position is determined at two points in this way, the direction of the vehicle 1 between these passing points can be found as the direction of a line connecting the two points.
The precise direction, in addition to its position, is determined in this way (Step 105). Consequently, after this stage, where the initial position and direction are determined, it becomes possible to calculate its serial position and direction with known dead reckoning technology.
Even after the vehicle 1 enters the traveling area 20 (Step 106), the serial position and direction within the traveling area 20 can be estimated and calculated.
The vehicle 1 travels along a predetermined traveling path L within the traveling area 20. At this time, the actual position of each of the predetermined passing marks 24-5, 24-6, 24-7 ..., on the predetermined traveling path L over which the vehicle 1 passes, are measured in sequence in the same way as the marks 40 and 41.
As a result, the estimated and calculated positions are corrected serially according to the actual positions on the mark measured in sequence and the vehicle 1 can travel precisely along the predetermined traveling path L.
Moreover, this embodiment is explained with the presupposition that the standby position 19 and the marks 40 and 41 used for the initial settings are external to the traveling area 20, but the standby position may also be established at a known position within the traveling area 20.
Also, the position and direction of the vehicle 1 remain the same as before the power was turned off in the case where the vehicle 1 is driven to the standby point, stopped temporarily and the power is cut, then the vehicle 1 is let stand at that position, the power is turned on once more, then the vehicle 1 is started. In such a case, the data from directly before the power is cut off can be used without any processing as the data for the initial position and direction when the power is turned on.
Figure 12 is a diagram to show the situation where the error in its estimated position increases with the progress of the vehicle 1, which estimates and calculates its position with the dead reckoning technology.
Specifically, even if the position of the vehicle 1 is accurately measured at the initial position, the range of error reaches a size corresponding to 18a when the vehicle 1 advances just by distance a. In effect, it is known that the vehicle 1 is within that error range 18a, but the precise position within the error range 18a cannot be specified. In the same way, the error range grows to 18b, 18c, 18d, and 18f when the traveling distance of the vehicle 1 extends to b, c, d, and f.
When the traveling distance is b, the error range 18b is sufficiently less than the area 24a of the mark body 24.
Therefore it is at least determined that the vehicle 1 is present on the mark body 24. Because the orientation and central position of the mark body 24 are known, the precise position on the mark 24 can be measured by the vehicle 1 passing the mark body 24 and detecting that all line segments were crossed; this being the case, the vehicle 1 can update its precise position through correction at that time.
However, the vehicle 1 fails to detect the mark 24 at any of distances a, b, c, and d and could just barely detect the mark 24 at distance f.
In this case, the error range 18f at distance f becomes much greater than an individual mark 24a; the mark detected here cannot ultimately be determined to be a particular mark.
In effect, the surrounding marks 24b, 24c, 24d, 24e, and 24f, in addition to the mark 24a, are all within the error range 18f. Therefore, so long as sensors 5 and 6 normally pass the ; CA 02222124 1997-11-2~
mark 24 and detect all three line segments, the precise position on that mark 24 can be calculated, but it is not determined which mark is passed. Consequently, in this case, it cannot be updated to the precise coordinate position of the vehicle 1; the vehicle 1 fails to reduce the cumulative error due to the dead reckoning technology.
Specifically, in the case where the vehicle 1 travels on the interleaved marks 24, it is necessary to detect the next mark 24 correctly while the error range of the cumulative error due to the dead reckoning technology is sufficiently less than the area of the mark bodies 24. Therefore, consideration is given whether there is any problem regarding this issue in practical application.
For example, when the side wheel drive vehicle 1, wherein the space between the wheels 2 and 3 on the right and left is 60 cm and the wheel diameter is 200 mm, travels directly forward for 3 m on a fairly irregular office floor, it has produced a cumulative position error of 1 cm. This means that the vehicle can travel for a distance of ten of the mark bodies 24 with a side length of 30 cm. Consequently, if it is possible to correctly detect the next mark body 24 during the travel for a distance of ten times the side length of the marks 24, since the cumulative error range at that site is sufficiently less than the dimensions of the mark bodies 24, it becomes clear whether a position was measured by passing over a mark body 24 laid in a particular position and direction. According to the above, it is thought that there is no problem in practical application.
CA 02222124 1997-11-2~
Moreover, in the embodiment, it is presupposed that the vehicle 1 has wheels on the sides, but it may also be a vehicle with a single wheel. The method for finding the current position and direction by changing the length of travel of one wheel and the steering angle of that wheel is already known according to Japanese Patent Application No. 61-151421.
Also, in the embodiment, the position and direction of the vehicle 1 is estimated based on the travel length of the wheels, but a known inertial navigation method to find the current position based on an accelerometer and gyro signal may also be applied.
Also, in the embodiment, the explanation presupposes the case of using two sensors, but a larger number of sensors may also be used. In this case, depending also on the method of arrangement, the traveling distance of the detection interval of the marks 24 can generally be shortened.
Also, in the embodiment, sensors 5 and 6 are placed on the axis connecting the side wheels, but placement in other locations is naturally also possible. In effect, in the case where the car body is rigid and does not change form, the sensor loci and locus of the center of the car body can be made to correspond by the addition of an operation for geometrical coordinate transformation.
Also, in the embodiment, as shown in Figure 1, square marks 24 are prepared as the elements; the traveling area 20 is formed with these square marks 24 providing coverage in sequence so as to leave no gaps. However, a square unit 27 of CA 02222124 1997-11-2~
a combination of four square marks 24 may be prepared, the traveling area 20 may also be formed with this square unit 27 providing coverage in sequence so as to leave no gaps.
Likewise, a square unit 28 which is a combination of nine square marks 24 or a square unit ... which is a combination of sixteen marks may be prepared; the traveling area 20 may also be formed with these square units 28 ... providing coverage in sequence so as to leave no gaps.
Also, the traveling area 20 may be formed by directly laying down the line segments 23a-23c, rather than laying the square mark bodies 24 to form the traveling area 20.
Also, in the embodiment, it is presupposed that the marks 24 comprise line segments in a Z (N) form, but the line segments may be in other geometrical forms as well. For example, as shown in Figures 13(a)-13(e) and Figures 14(a)-14(c), marks 50-57 having line segments in various geometrical forms, which already became known in Japanese Patent Application No. 60-108792 (Japanese Patent Publication No. 7-3339), may also be used. Essentially, an arbitrary configuration can be used if it is a geometrical form at least having two line segments which are not parallel to each other and with which the actual position on a mark can be detected with a line segment crossing detector.
Also, in the embodiment, the course deviation (deviation of predetermined passing position on a mark from the actual passing position) attained through the detection of marks is used to correct the position estimated by dead reckoning, but the present invention is not limited to this. The use of the course deviation attained is arbitrary.
As explained above, the present invention attains the marked effects that the predetermined traveling path can be established arbitrarily across the entire traveling area and it is possible to respond flexibly to changes in the traveling route.
INDUSTRIAL APPLICABILITY
The present invention may also be applied to manned vehicles as well as automated vehicles; additionally, an arbitrary structure may be applied as the structure of the moving body.
Claims (7)
1. (Amended) A device for detecting a moving body deviating from a course, in which predetermined passing marks through which a moving body passes are arranged intermittently on a predetermined traveling path, so that all line segments constituting marks comprising at least a first and a second line segments which are not parallel to each other, cross the predetermined traveling path; an actual position on the predetermined passing marks is detected by detecting, by means of a line segment crossing detector mounted on the moving body, the crossing of all line segments constituting the predetermined passing marks during the traveling of the moving body; and a course deviation from the predetermined traveling path of the moving body is detected based on a predetermined passing position on the predetermined passing marks and the actual position on the predetermined passing marks which was detected, characterized in that:
a plurality of the marks are [respectively inclined and]
arranged in advance within a predetermined traveling area in a state where the marks adjacent to one another vertically and horizontally are rotated by 90° and the marks adjacent to one another in oblique directions are inclined at the same angle, so that a measurement reference axis crossing vertically with respect to a longitudinal direction of line segments constituting the mark is oriented in the vertical or horizontal direction of the predetermined traveling area through which the moving body must travel, and a distance between the plurality of the marks is previously set to a certain degree, so that, in the case where an arbitrary predetermined traveling path in the predetermined traveling area, through which the moving body must travel, is selected and the moving body is caused to travel along the arbitrary predetermined traveling path, the line segments crossing detector mounted on the moving body can detect the crossing of all line segments constituting the predetermined passing marks corresponding to the arbitrary predetermined traveling path.
a plurality of the marks are [respectively inclined and]
arranged in advance within a predetermined traveling area in a state where the marks adjacent to one another vertically and horizontally are rotated by 90° and the marks adjacent to one another in oblique directions are inclined at the same angle, so that a measurement reference axis crossing vertically with respect to a longitudinal direction of line segments constituting the mark is oriented in the vertical or horizontal direction of the predetermined traveling area through which the moving body must travel, and a distance between the plurality of the marks is previously set to a certain degree, so that, in the case where an arbitrary predetermined traveling path in the predetermined traveling area, through which the moving body must travel, is selected and the moving body is caused to travel along the arbitrary predetermined traveling path, the line segments crossing detector mounted on the moving body can detect the crossing of all line segments constituting the predetermined passing marks corresponding to the arbitrary predetermined traveling path.
2. (Not Amended) The device for detecting a moving body deviating from a course according to Claim 1, characterized in that, in the case of estimating a current position of the moving body based on detection outputs of direction detection means and traveling distance detection means which are mounted on the moving body and effecting steering control of the moving body based on the estimated position so that the moving body passes in sequence predetermined passing points on the predetermined traveling path instructed in advance, the estimated position is intermittently corrected based on the detected course deviation.
3. (Amended) The device for detecting a moving body deviating from a course according to Claim 1, characterized in that [a plurality of marks are arranged in advance within the predetermined traveling area in a state where the marks adjacent to one another vertically and horizontally are rotated by 90° and the marks adjacent to one another in oblique directions are inclined at the same angle] marks, of the line segments arranged on a square base plate, are prepared and laid in sequence so as not to leave gaps in the predetermined traveling area, whereby a plurality of marks are arranged within the predetermined traveling area.
4. (Amended) The device for detecting a moving body deviating from a course according to Claim 3, characterized in that [marks, of the line segments arranged on a square base plate, are prepared and laid in sequence so as not to leave gaps in the predetermined traveling area, whereby a plurality of marks are arranged within the predetermined traveling area]
square units, of a combination of the square marks, are prepared and laid in sequence so as not to leave gaps in the predetermined traveling area, whereby the plurality of marks are arranged within the predetermined traveling area.
square units, of a combination of the square marks, are prepared and laid in sequence so as not to leave gaps in the predetermined traveling area, whereby the plurality of marks are arranged within the predetermined traveling area.
5. (Amended) The device for detecting a moving body deviating from a course according to Claim [4] ~, characterized in that [square units, of a combination of the square marks, are prepared and laid in sequence so as not to leave gaps in the predetermined traveling area, whereby the plurality of marks are arranged within the predetermined traveling area] two or more of the line segment crossing detectors are disposed in a vertical direction with respect to a moving direction of the moving body by separating from each other by a predetermined distance, d= (N+1/2) / ~2x100%
where a length in the longitudinal direction of the line segment constituting the marks is 100% and N is an integer.
where a length in the longitudinal direction of the line segment constituting the marks is 100% and N is an integer.
6. The device for detecting a moving body deviating from a course according to Claim [1] ~, characterized in that the distance between the two or more of the line segment crossing detectors [are placed at a specific distance from each other at right angles to a direction of movement of the moving body] is set as being shifted by not more than a predetermined amount with respect to the predetermined distance d.
7. The device for detecting a moving body deviating from a course according to Claim 2, characterized in that the steering control of the moving body is effected in such a manner that, at least two marks are arranged in front of a position of progress of the predetermined traveling area, an actual position on the marks detected when the moving body passes these at least two marks is determined as an initial position and, a direction of progress of the moving body determined from each of the actual positions on two or more of the marks detected when the moving body passes these at least two marks is determined as an initial direction.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7128355A JPH08320227A (en) | 1995-05-26 | 1995-05-26 | Course deviation detecting device for moving body |
| JP128355/1995 | 1995-05-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2222124A1 true CA2222124A1 (en) | 1996-11-28 |
Family
ID=14982777
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002222124A Abandoned CA2222124A1 (en) | 1995-05-26 | 1996-05-27 | Device for detecting moving body deviating from course |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPH08320227A (en) |
| CN (1) | CN1185206A (en) |
| AU (1) | AU5780396A (en) |
| CA (1) | CA2222124A1 (en) |
| GB (1) | GB2316484A (en) |
| WO (1) | WO1996037756A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2353909B (en) * | 1999-08-28 | 2004-03-17 | John Alfred Cawkwell | Robot positioning and motion mechanism |
| SE519435C2 (en) * | 2000-03-21 | 2003-02-25 | Anoto Ab | Floors and vehicles and method for controlling a vehicle using a position coding pattern |
| CN102298388B (en) * | 2011-08-22 | 2012-12-19 | 深圳市银星智能科技股份有限公司 | Restriction system for mobile robot |
| CN109269494B (en) * | 2014-02-28 | 2022-08-02 | 原相科技股份有限公司 | Tracking system |
| CN104075718B (en) * | 2014-06-10 | 2016-08-31 | 厦门大学 | Pedestrian's track route localization method of fixing circuit |
| CN106970621B (en) | 2017-04-17 | 2021-03-30 | 北京京东乾石科技有限公司 | Transfer robot operation control method and device and robot |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS548280A (en) * | 1977-06-20 | 1979-01-22 | Toshihiro Tsumura | Device for correcting direction of moving object |
| SE423840B (en) * | 1980-10-02 | 1982-06-07 | Volvo Ab | VIEW THROUGH A WHEEL-DRIVED DRIVE VEHICLE TO PROVIDE AN UPDATE |
| NL8500529A (en) * | 1985-02-25 | 1986-09-16 | Ind Contractors Holland Bv | SYSTEM FOR DETERMINING THE POSITION OF A VEHICLE NOT BONDED TO A FIXED TRACK. |
| JPH073339B2 (en) * | 1985-05-21 | 1995-01-18 | 株式会社小松製作所 | Detecting device for direction and position of unmanned vehicle |
| JPH07104718B2 (en) * | 1985-09-27 | 1995-11-13 | 株式会社小松製作所 | Driving course teaching device for unmanned vehicles |
| JPS62113210A (en) * | 1985-11-11 | 1987-05-25 | Nec Corp | Guide path for unmanned vehicle |
-
1995
- 1995-05-26 JP JP7128355A patent/JPH08320227A/en active Pending
-
1996
- 1996-05-27 GB GB9724998A patent/GB2316484A/en not_active Withdrawn
- 1996-05-27 CA CA002222124A patent/CA2222124A1/en not_active Abandoned
- 1996-05-27 CN CN96194157A patent/CN1185206A/en active Pending
- 1996-05-27 AU AU57803/96A patent/AU5780396A/en not_active Abandoned
- 1996-05-27 WO PCT/JP1996/001416 patent/WO1996037756A1/en active Search and Examination
Also Published As
| Publication number | Publication date |
|---|---|
| GB2316484A (en) | 1998-02-25 |
| AU5780396A (en) | 1996-12-11 |
| WO1996037756A1 (en) | 1996-11-28 |
| JPH08320227A (en) | 1996-12-03 |
| CN1185206A (en) | 1998-06-17 |
| GB9724998D0 (en) | 1998-01-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |