EP2216445A1

EP2216445A1 - Vehicle type drawing apparatus

Info

Publication number: EP2216445A1
Application number: EP08845504A
Authority: EP
Inventors: Shoichi Imanishi; Takuo Ohara; Koji Mikami; Shinji Uchida; Koji Ogura
Original assignee: Gikousha KK
Current assignee: Gikousha KK
Priority date: 2007-10-31
Filing date: 2008-10-22
Publication date: 2010-08-11
Also published as: JPWO2009057494A1; JP4460029B2; CN101835943B; EP2216445A4; CN101835943A; WO2009057494A1; KR101220656B1; KR20100071093A

Abstract

There is provided a vehicle-type drawing apparatus that enables the operation of drawing a rough design called inking on the road surface to be facilitated remarkably. By use of left and right drive wheels 3L, 3R that are provided on a same wheel shaft, that are rotatable in same directions or in reverse directions, and that are driven respectively; a driven wheel 10 having a spherical shape and arranged at a position apart from an intermediate portion between the left and right drive wheels 3L, 3R by a given distance; a marking device 11 that is arranged at an intermediate portion of the left and right drive wheels 3L, 3R. While a controller 32 is controlling drive states of the left and right drive wheels 3L, 3R, the marking device 11 marks the line or the design pattern on the road surfaces, thereby enabling drawing of any line or design pattern from an arc with a small diameter to a straight line.

Description

Technical Field

The present invention relates to drawing apparatuses for drawing lines or design patterns on drawing objects such as road surfaces, for example, and in particular, to a vehicle-type drawing apparatus suitable for so-called inking before painting.

Background Art

In general, lane markers and road surface markings drawn on road surfaces are displayed by drawing rough designs called inking and then painting them. To this end, Patent Document 1 listed below discloses a technique of drawing the road surface markings on the road surfaces with the use of a road surface marking application system mounted on a small-sized truck. While the road surface marking application system is being transported on this small-sized truck, left and right paint discharge openings arranged in a line at a paint applicator are opened and closed according to the patterns for drawing the road markings on the road surfaces. Also, Patent Document 2 listed below discloses a technique of ensuring the security of an operator while the operator is driving a wirelessly-operated traffic lane marking machine by wireless to discharge the paint on the road surfaces.

Patent Document 1: JP H7-34414 A
Patent Document 2: JP H5-214711 A

Disclosure of the Invention

Problems to be Solved by the Invention

According to Patent Document 1, on the assumptions that extremely accurate drive of the small-sized truck and extremely and highly accurate paint discharge to be linked with the moving state of the small-sized truck, it is made possible to automate drawing the markings on the road surfaces by directly discharging the paint on the road surfaces without drawing a rough design. However, the extremely accurate drive of the small-sized truck is difficult itself, and the extremely and highly accurate paint discharge to be linked with it is also difficult. Hence, neither of the above assumptions is realistic. Meanwhile, according to Patent Document 2, since the wirelessly-operated traffic lane marking machine is operated remotely by wireless, the security of the operator is ensured. However, the operator has to draw rough designs called inking as ever, as described above. In fact, the working hours and experiences are needed most for drawing the rough designs called inking among the operations of drawing the markings on the road surfaces, such as lane markers or road surface markings. Drawing the rough designs actually holds more than 60 percents of the entire working hours of the operations of drawing the markings on the road surfaces. Nevertheless, no method has been developed for facilitating the operation of drawing the rough designs called inking.
The present invention has been made in view of the above circumstances and has an object of providing a vehicle-type drawing apparatus that enables the operation of drawing a rough design called inking on the road surface to be facilitated remarkably, for example.

Means for Solving the Problems

In order to solve the above problems, according to the present invention, there is provided a vehicle-type drawing apparatus for drawing a line or a design pattern on a drawing object that is relatively flat, the apparatus comprising: two drive wheels that are provided on a same wheel shaft, that are rotatable in same directions or in reverse directions, and that are driven respectively; a driven wheel that is arranged at a position apart from an intermediate portion between the two drive wheels by a given distance in a direction perpendicular to the wheel shaft, and that is rotatable in a free direction with respect to the drawing obj ect; a marking device that is arranged at an intermediate portion of the two drive wheels and that is capable of marking the line or the design pattern on the drawing object; and a controller that causes the marking device to draw the line or the design pattern on the drawing obj ect by marking the line or the design pattern on the drawing object, while controlling drive states of the two drive wheels.
According to the vehicle-type drawing apparatus described above is capable of drawing any line or design pattern from an arc with a small diameter to a straight line, thereby enabling, for example, the operation of drawing a rough design called inking on the road surface to be facilitated remarkably.
In addition, the vehicle-type drawing apparatus according to the present invention, when seen in a plan view, the gravity center of the entire vehicle-type drawing apparatus is made to locate at a position that is apart from the intermediate portion between the two drive wheels by a given distance to the driven wheel side, and that is lower than the wheel shaft of the two drive wheels.
According to the vehicle-type drawing apparatus described above, while tracing the drawing object with accuracy with the two drive wheels and one driven wheel, the vehicle-type drawing apparatus does not disturb the marking operation of the marking device arranged at an intermediate portion of the two drive wheels. Additionally, the gravity center of the vehicle-type drawing apparatus is made to be lower than the wheel shaft of the drive wheels, thereby preventing the uplift of the driven wheel at the time of crash stop.
In addition, the vehicle-type drawing apparatus according to the present invention further comprises drive state sensors that sense drive states of the two drive wheels, respectively, wherein the controller calculates information on a position of the vehicle-type drawing apparatus from the drive states of the two wheel shafts that have been sensed by the drive state sensors.
According to the vehicle-type drawing apparatus described above, it is possible to recognize which direction the vehicle faces and where the vehicle is positioned at any time. It is made possible to draw a curve line according to the curvature factor or curvature radius of the drawing object that has been input, draw a curve line by performing arc interpolation of the positions of three points on the drawing object that have been input, and draw a design pattern that has been input beforehand.
In addition, the vehicle-type drawing apparatus according to the present invention further comprises an antiskid material is provided at the two drive wheels.
According to the vehicle-type drawing apparatus described above, it is made possible to calculate the information on the position of the apparatus with accuracy from the drive states of the two drive wheels that have been sensed.
In addition, in the vehicle-type drawing apparatus according to the present invention, the driven wheel is a ball.
According to the vehicle-type drawing apparatus described above, an unnecessary movement occurring when the drive states of the two drive wheels are controlled is preventable, thereby allowing accurate calculation of the position information and accurate drawing.
In addition, in the vehicle-type drawing apparatus according to present invention, the marking device brings a metallic circular disc that is rotating into contact with the drawing object to mark the line or the design pattern on the drawing object with metallic powders of the metallic circular disc.
According to the vehicle-type drawing apparatus described above, after painting, since the metallic powders for markings can be removed with relative ease, they are suitable for drawing rough designs of the lane markers or road surface markings.
In addition, in the vehicle-type drawing apparatus according to the present invention, the metallic circular disc is made of aluminum.
According to the vehicle-type drawing apparatus described above, since the metallic circular disc is made of aluminum, the metallic circular disc that is cheap is obtainable and any damage on the road surfaces is preventable, for example.
In addition, in the vehicle-type drawing apparatus according, the controller includes a drawing circular disc state calculator that detects a wear status of the metallic circular disc from the state where the metallic circular disc is in contact with the drawing object.
According to the vehicle-type drawing apparatus described above, it is possible to detect the time for replacement of the metallic circular disc, and it is also possible to control the rotation state of the metallic circular disc so that the circumferential velocity of the metallic circular disc should be constant.
In addition, the vehicle-type drawing apparatus according to the present invention, the drawing circular disc state calculator controls a rotation state of the metallic circular disc to make an outer circumferential velocity constant from the wear status of the metallic circular disc.
According to the vehicle-type drawing apparatus described above, stable marking is achievable, and in addition, unnecessary wear of the metallic circular disc is preventable.
In addition, the vehicle-type drawing apparatus according to present invention further comprises a touch sensor that senses any touch from the exterior, wherein the controller stops drawing in the event that the touch sensor senses any touch from the exterior.
According to the vehicle-type drawing apparatus described above, it is made possible to avoid any displacement in the position information that has been detected from the drive states of the drive wheels and it is also avoid drawing of a wrong line or a wrong design pattern.
In addition, in the vehicle-type drawing apparatus according to present invention, cooling air for cooling down the controller is supplied to a drive system of the two drive wheels and a drive system of the metallic circular disc, and is then blown out of the wheel shaft of the two drive wheels and a rotation shaft of the metallic circular arc to the exterior.
According to the vehicle-type drawing apparatus described above, it is possible to cool down the drive system of the drive wheels and the drive system of the metallic circular disc. Additionally, it is possible to suppress and prevent dusts and refuses from entering the drive systems.
In addition, in the vehicle-type drawing apparatus according to present invention, the controller further includes a curve line drawing portion that draws a curve line on the drawing object, and the curve line drawing portion includes a data input curve line drawing portion that draws the curve line according to a curvature factor or a curvature radius of the drawing object that has been input, and a circular arc interpolation curve line drawing portion that performs arc interpolation on locations of three points on the drawing object that have been input and then draws the curve line.
According to the vehicle-type drawing apparatus described above, for example, even if the curvature factor or curvature radius of the road is known or is not, it is possible to draw a curve line with accuracy.
In addition, in the vehicle-type drawing apparatus according to the present invention, the controller further includes a design pattern drawing portion that draws the design pattern on the drawing object, and the design pattern drawing portion includes a vehicle direction calculation corrector that calculates a direction that the vehicle faces from positions of two points that have been marked on a straight line on the drawing object and then corrects the direction.
According to the vehicle-type drawing apparatus described above, it is made possible to draw the design pattern with accuracy in a designated direction of the road, for example.

Brief Description of the Drawings

FIG. 1A to FIG. 1C illustrate a schematic configuration diagram of a vehicle-type drawing apparatus according to an embodiment of the present invention;
FIG. 2A and FIG. 2B are perspective diagrams of the vehicle-type drawing apparatus illustrated in FIG. 1A to FIG. 1C;
FIG. 3 is a diagram illustrative of flows of cooling air in the vehicle-type drawing apparatus illustrated in FIG. 1A to FIG. 1C;
FIG. 4 is a block diagram of a controller in the vehicle-type drawing apparatus illustrated in FIG. 1A to FIG. 1C;
FIG. 5 is a block diagram illustrative of functional portions of the controller of FIG. 4;
FIG. 6A and FIG. 6B are diagrams illustrative of drawing a curve line;
FIG. 7A to FIG. 7C are diagrams illustrative of calculation and correction of the direction of a vehicle body; and
FIG. 8A to FIG. 8D are diagrams illustrative of another example of a marking device.

Explanation of References

1: vehicle body, 3L, 3R: left and right drive wheels, 4L, 4R: left and right drive wheels driving motors, 8L, 8R: left and right drive cases, 9: antiskid material, 10: driven wheel, 11: marking device, 12: drawing circular disc, 13: drawing circular disc rotation motor, 17: drawing mechanism case, 18: swing shaft, 19: drawing mechanism moving up-and-down motor, 20: crank, 21: rotation angle sensor, 22: control case, 25: air blower motor, 26: air blower, 27 to 30: flexible ducts, 31: touch sensor, 32: controller, 33: CPU, 34: interface, 35: memory device, 36L, 36R, 37 to 39: drivers, 40L, 40R: drive state sensors, 41: straight line drawing portion, 42: curve line drawing portion, 43: data input curve line drawing portion, 44: circular arc interpolation curve line drawing portion, 45: design pattern drawing portion, 46: vehicle direction calculation corrector, 47: left drive wheel drive state calculator, 48: right drive wheel drive state calculator, 49: drawing circular disc state calculator

Best Mode for Carrying Out the Invention

A description will now be given of a vehicle-type drawing apparatus for use in inking in the drawing of markings on the road surfaces as an embodiment of the vehicle-type drawing apparatus according to the present invention.
FIG. 1A to FIG. 1C illustrate an entire configuration diagram of a vehicle-type drawing apparatus according to the present embodiment. FIG. 1A is a plan view, FIG. 1B is a left-side view, and FIG. 1C is a front view. Additionally, FIG. 2A and FIG. 2B are perspective diagrams of the vehicle-type drawing apparatus illustrated in FIG. 1A to FIG. 1C. FIG. 2A is a plan view, and FIG. 2B is a left-side view. The vehicle-type drawing apparatus according to the present embodiment is capable of driving by itself. Its main components are arranged in a vehicle body 1, and are connected to an exterior remote controller via a wiring connection tube 2. Incidentally, the interior components of the vehicle body 1 are supplied with power via the wiring connection tube from an exterior power supply.
Reference numerals 3L and 3R in the figures are left and right drive wheels arranged slightly on the right side in the vehicle body 1 in the left-side view of FIG. 1B or FIG. 2B. These left drive wheel 3L and right drive wheel 3R are mounted on the same wheel shaft, and are driven by respective motors which are a left drive wheel driving motor 4L and a right drive wheel driving motor 4R. There are provided drive pulleys 5L and 5R on the rotation shafts of the left drive wheel driving motor 4L and the right drive wheel driving motor 4R, respectively. There are provided driven pulleys 6L and 6R on the wheel shaft of the left drive wheel 3L and the right drive wheel 3R, respectively. Belts 7L and 7R are wound around the drive pulleys 5L and 5R, and the driven pulleys 6L and 6R, respectively. Both of the left drive wheel driving motor 4L and the right drive wheel driving motor 4R are stepper motors, and are capable of rotating in any direction by the number of steps to be input. Hence, the left drive wheel 3L and the right drive wheel 3R are capable of rotating in the same directions or in the reverse directions with each other.
Incidentally, the rotation shaft of the left drive wheel driving motor 4L, the drive pulley 5L, the driven pulley 6L, and the belt 7L are housed in a left drive case 8L in an almost hermetic state, and only the wheel shaft of the left drive wheel 3L is externally communicated in the left drive case 8L. Likewise, the rotation shaft of the right drive wheel driving motor 4R, the drive pulley 5R, the driven pulley 6R, and the belt 7R are housed in a right drive case 8R in an almost hermetic state, and only the wheel shaft of the right drive wheel 3R is externally communicated in the right drive case 8R. In addition, antiskid materials 9 constructed of rubber belts are provided at the outer circumferences of the left drive wheel 3L and the right drive wheel 3R, respectively.
A driven wheel 10 is arranged between the left drive wheel 3L and the right drive wheel 3R in a direction perpendicular to the wheel shaft thereof. The driven wheel 10 is required to be a free wheel that freely rotates in any direction with respect to the road surface. According to the present embodiment, the driven wheel 10 is composed of a ball. As a free wheel, a known caster is conceivable, for example. However, according to the present embodiment, the left drive wheel 3L and the right drive wheel 3R rotate in reverse directions or in the same directions repeatedly. Therefore, for example, when both of the drive wheels 3L and 3R rotating in the same directions are made to change their rotations to the reverse directions, an unnecessary movement occurs at the vehicle body 1 according to the difference between the position of mounting a caster on the vehicle body and the wheel shaft of the caster. In light of this, when the driven wheel 10 is composed of a ball, the ball is capable of rotating at any time in any direction theoretically as far as the ball is in point contact with the road surface and the rotary inertia is suppressed. In fact, the driven wheel 10 composed of a ball is rotatably supported by the vehicle body 1 with three balls.
There is provided a marking device 11 at an intermediate portion of the left drive wheel 3L and the right drive wheel 3R, and there is provided a drawing circular disc 12 for providing a marking on the road surface at an intermediate portion of the both drive wheels 3L and 3R. This drawing circular disc 12 is an aluminum circular disc, and is rotated by a drawing circular disc rotation motor 13. A drive pulley 14 is attached to the rotation shaft of the drawing circular disc rotation motor 13, a driven pulley 15 is attached to the rotation shaft of the drawing circular disc 12, and a belt 16 is wounded around the drive pulley 14 and the driven pulley 15. When the drawing circular disc 12 composed of such a metallic circular disc is brought into contact with the road surface with the drawing circular disc 12 being made to rotate, the drawing circular disc 12 made of aluminum is ground down and metallic powders of aluminum are adhered to the road surface. According to the present embodiment, by use of the metallic powders of aluminum, lines or design patterns are drawn on the road surfaces. Moreover, the rotation shaft of the drawing circular disc rotation motor 13, the drive pulley 14, the driven pulley 15, and the belt 16 are housed in a drawing mechanism case 17 in an almost hermetic state, whereas only the rotation shaft of the drawing circular disc 12 is externally communicated in the interior of the drawing mechanism case 17.
The drawing mechanism case 17 is attached to the vehicle body 1 to be capable of swinging in the up and down directions via a swing shaft 18 arranged on the driven wheel 10 side. Meanwhile, a drawing mechanism moving up-and-down motor 19 is arranged at the opposite side of the swing shaft 18 with respect to the drawing mechanism case 17. A crank arm 20 is attached to its rotation shaft, so that the crank arm 20 supports the bottom surface of the drawing mechanism case 17. Therefore, when the drawing mechanism moving up-and-down motor 19 is rotated and then the bottom surface of the drawing mechanism case 17 is pushed upwardly by the crank arm 20, the drawing mechanism case 17 rotates around the swing shaft 18 upwardly and the drawing circular disc 12 becomes spaced apart from the road surface. When the drawing mechanism moving up-and-down motor 19 is reversely rotated and then the support for the drawing mechanism case 17 by means of the crank arm 20 is released, the drawing mechanism case 17 rotates around the swing shaft 18 downwardly and the drawing circular disc 12 becomes in contact with the road surface. That is to say, when the vehicle-type drawing apparatus according to the present embodiment does not draw a marking on the road surface, the drawing mechanism moving up-and-down motor 19 is rotated to make the drawing circular disc 12 spaced apart from the road surface, whereas only when the vehicle-type drawing apparatus according to the present embodiment draws a marking on the road surface, the drawing mechanism moving up-and-down motor 19 is reversely rotated to bring the drawing circular disc 12 into contact with the road surface. Additionally, the swing shaft 18 of the drawing mechanism case 17 is provided with a rotation angle sensor 21.
In the vehicle body 1, a hermetic control case 22 is provided above the left drive case 8L, the right drive case 8R, the driven wheel 10, and the marking device 11, and the control case 22 includes therein a main board mounting a CPU thereon, an I/O board 24 provided with an interface and a driver, and a memory board + mounting a memory device thereon. Below the control case 22, a blower 27 to be driven by a blower motor 26 to rotate is arranged and the blower 27 and the control case 22 are connected by a flexible duct 28. Also, the control case 22 and the left drive case 8L, and the control case 22 and the right drive case 8R are connected by flexible ducts 29, respectively, whereas the control case 22 and the drawing mechanism case 17 are connected by a flexible duct 30.
Hence, as illustrated in FIG. 3, cooling air supplied into the control case 22 from the blower 27 cools down the interior of the control case 22, and is then supplied into the left drive case 8L, the right drive case 8R, and the drawing mechanism case 17. After cooling down the drive system in the left drive case 8L, the cooling air is blown out of the wheel shaft of the left drive wheel 3L to the exterior. After cooling down the drive system in the right drive case 8R, the cooling air is blown out of the wheel shaft of the right drive wheel 3R to the exterior. After cooling down the drive system in the drawing mechanism case 17, the cooling air is blown out of the rotation shaft of the drawing circular disc 12 to the exterior. As described above, since the markings are drawn on the road surfaces by aluminum powders of the drawing circular disc 12 made of aluminum according to the present embodiment, the powders might be stirred up in the vicinity of the apparatus. Besides, dusts and refuses exist on the road surfaces. According to the present embodiment, the cooling air of the apparatus is blown out of the wheel shaft of the drive wheels 3L and 3R and the rotation shaft of the drawing circular disc 12 to the exterior, thereby suppressing and preventing the dusts and refuses from entering the interior of the drive systems.
In addition, four corners in the plane view of the vehicle body 1 are provided with touch sensors 31 each composed of, for example, a piezoelectric element or a touch switch. According to the present embodiment, the position information of the vehicle is acquired from the drive states of the left and right drive wheels 3L and 3R, specifically, from the drive states of the left and right drive wheels driving motors 4L and 4R. If the vehicle-type drawing apparatus touches something or something touches the vehicle-type drawing apparatus, the drive states of the left and right drive wheels 3L and 3R will be inconsistent with the movement state of the vehicle-type drawing apparatus. If so, accurate position information won't be acquirable, it will be impossible to achieve markings on the road surface with a high degree of accuracy, as a result. For this reason, in the event that the touch sensor 31 sensors any touch from the exterior, drawing is caused to stop temporarily.
Further, according to the present embodiment, the gravity center of the entire apparatus maintains its weight balance to locate at a position (indicated by a figure of circle colored with alternately arranged black and white) apart from the intermediate portion of the left and right drive wheels 3L and 3R to the driven wheel 10 side by only a given distance, in the plan view of FIG. 2A. In the vehicle-type drawing apparatus according to the present embodiment, in the state where the drawing circular disc 12 of the marking device 11 is in contact with the road surface while the drawing circular disc 12 is being rotated, for example, the left and right drive wheels 3L and 3R are rotated in reverse directions with a slight speed difference, thereby enabling a circular arc with an extremely small diameter to be drawn on the road surface. The left and right drive wheels 3L and 3R are synchronized to rotate in the same directions, thereby enabling a substantially perfect straight line to be drawn on the road surface. Incidentally, the left and right drive wheels 3L and 3R are rotated with a phase difference in the same directions, thereby enabling a circular arc to be drawn with a small curvature factor, that is, a circular arc with a great curvature radius. Moreover, a given design pattern is enabled to be drawn on the road surface by a combination thereof. For instance, the road surface markings such as number symbols for speed limit and the road surface markings such as arrows for limiting the direction of movement have defined sizes in compliance with traffic laws and regulations. The vehicular swept path according to the size of the design pattern, specifically, the drive states of the left and right drive wheels 3L and 3R are memorized beforehand, and then the left and right drive wheels 3L and 3R, that are, the left and right drive wheels driving motors 4L and 4R are driven in accordance with the drive states, so that a given design pattern can be drawn on the road surface.
In order to trace the road surface by means of the two left and right drive wheels 3L and 3R and a single driven wheel 10, it is necessary to arrange the center gravity at the inside of a triangle connecting the contact points of the aforementioned wheels. However, if the gravity center of the entire apparatus is situated too closer to the driven wheel 10 side, the load of the driven wheel 10 will be too great. The driven wheel 10 according to the present embodiment is a ball and is made to rotate easily in any direction of the road surface, but if the load of the driven wheel 10 is too great, the frictional resistance will be increased. Therefore, in a case where the left and right drive wheels 3L and 3R are rotated with a phase difference or rotated in reverse directions, the movement of the vehicle body 1 is disturbed by the frictional resistance of the driven wheel 10. This might inhibit a marking to be provided by the marking device 11. On the other hand, if the gravity center of the entire apparatus is situated too closer to the wheel shaft side of the left and right drive wheels 3L and 3R, for instance, the load of the driven wheel 10 will be reduced on a slope where the left and right drive wheels 3L and 3R are located on the lower side of the slope, thereby making it impossible to trace the road surface with accuracy. Accordingly, the gravity center of the entire apparatus is situated at a position apart from the intermediate portion of the left and right drive wheels 3L and 3R to the driven wheel 10 side by only a given distance in the plan view.
A controller of the vehicle-type drawing apparatus according to the present embodiment is composed of a main board 23, an I/O board 24, and a memory board 25 included in the control case 22. The outline of the controller is illustrated as a block diagram of FIG. 4. A controller 32 includes: a CPU 33 that controls arithmetic processing; an interface 34 that adapts inputs and outputs of various sensors and data; a memory device 35 that stores various programs and results of arithmetic processes; and drivers 36L, 36R, and 37 to 39 that convert control signals from the CPU 33 to drive signals of an actuator. Also, the drive states of the left and right drive wheels driving motors 4L and 4R composed of step motors are monitored by drive state sensors 40L and 40R, respectively. Incidentally, a data input portion 101, a data output portion 102, and a display portion 103 are arranged at a remote controller.
In fact, FIG. 6 illustrates a block diagram of functional portions, which are configured in the controller 32 by arithmetic processing in accordance with programs. According to the present embodiment, the controller 32 includes as functional portions; a straight line drawing portion 41; a curve line drawing portion 42; a design pattern drawing portion 45; a left drive wheel drive state calculator 47; a right drive wheel drive state calculator 48; and a drawing circular disc state calculator 49. The curve line drawing portion 42 includes a data input curve line drawing portion 43; and a circular arc interpolation curve line drawing portion 44. The design pattern drawing portion 45 includes a vehicle direction calculation corrector 46. The straight line drawing portion 41 draws a straight line on the road surface by synchronizing the left and right drive wheels 3L and 3R to drive to rotate in the same directions with the vehicle facing a direction of drawing the straight line.
The data input curve line drawing portion 43 in the curve line drawing portion 42 draws a curve line of circular arc on the road surface according to the curvature factor or curvature radius of the road input from the data input portion 101. Specifically, as illustrated in FIG. 6A, for example, there is a case where a lane marker forming an outside line is painted at a position spaced apart by a given distance from the side edge of the road. At the time of inking that is drawing a rough design, a curvature radius of a circular arc of the side edge of the road in the inside of the circular arc, for example, is input from the data input portion 101 with the vehicle body 1 situated at a transition position from a straight line to a curve line and facing the drawing start direction of the curve line of the circular arc to be drawn, that is, facing a direction of tangent of the curve line of the circular arc. Then, the data input curve line drawing portion 43 sets a movement locus of the drawing circular disc 12 of the marking device 11 with a radius to which the distance to the outside line to be spaced apart is added, and then sets the movement locus of the left and right drive wheels 3L and 3R necessary for moving along the locus.
The circular arc interpolation curve line drawing portion in the curve line drawing portion 42 performs arc interpolation of the positional data of the three points input by the remote controller moving the apparatus, calculates the curvature factor or curvature radius of the curve line of circular arc to be drawn, and draws the curve line of circular arc on the road surface. Specifically, as illustrated in FIG. 6B, for example, there is a case where a lane marker forming an outside line is painted at a position spaced apart by a given distance from the side edge of the road. At the time of inking that is drawing a rough design, the vehicle body 1 is moved to a start point of the curve line of circular arc for the rough design by the remote controller, the location is memorized. Then, the vehicle body 1 is moved to an intermediate portion (anywhere except the start point and end point) of the curve line of circular arc for the rough design by the remote controller, so the location is memorized. Subsequently, the vehicle body 1 is moved to an end point of the curve line of circular arc for the rough design by the remote controller, so the location is memorized. In the meantime, the vehicle body 1 may face in any direction. In the controller 32, since the drive state sensors 40L and 40R monitor the drive states of the left and right drive wheels driving motors 4L and 4R, respectively, it is possible to monitor in which direction the vehicle body 1 faces. It is also possible to extract only the positional data of the three points that have been input, in consideration of the monitoring result. Such extracted positional data of the three points determines only one circular arc that passes through the start point, the intermediate portion, and the end point of the curve line of circular arc. The movement locus of the drawing circular disc 12 of the marking device 11 is set with the curvature factor or the curvature radius of the curve line of circular arc, and then the movement locus of the left and right drive wheels 3L and 3R necessary for moving the locus is set.
The design pattern drawing portion 45 memorizes beforehand the movement locus of the left and right drive wheels 3L and 3R necessary for drawing the road surface markings that have sizes defined by the traffic laws and regulation as described above. In addition, regarding the road surface markings that do not have defined sizes, when the size of the road surface marking is input, the road surface marking itself is set as the movement locus of the drawing circular disc 12 of the marking device 11, so the movement locus of the left and right drive wheels 3L and 3R necessary for moving the locus is set.
Even if the movement locus of the left and right drive wheels 3L and 3R for drawing the design pattern in this manner, it is necessary for the vehicle to face in a direction necessary for drawing the design pattern on the actual road surface correctly in order to draw the design pattern on an actual road surface correctly. For this end, the vehicle direction calculation corrector 46 included in the design pattern drawing portion 45 calculates the direction of the vehicle to be described below, for example, and then corrects the direction. That is, in a case where a road marking indicated by a chain double-dashed line as illustrated in FIG. 7C is to be drawn in parallel to the side edge of a straight road and the vehicle has to face in a direction parallel to a reference line, passing through a drawing start point, in parallel to the side edge of the road, a first point is marked at a position with the vehicle located in the vicinity of the drawing start point but not located at the drawing start point and with the vehicle not facing in a direction parallel to the reference line. Then, the vehicle moves linearly a distance L₀ in the direction that the vehicle faces, and that point is marked. For instance, the drawing reference point and X-axis coordinate X₁ and Y-axis coordinate Y₁ of the first marked point are measured and input, where X-axis denotes widthwise direction of a road and Y-axis denotes lengthwise direction thereof. Next, the reference line (or the drawing start point) and X-axis coordinate X₂ of the second marked point are measured and input. These coordinates tell the direction of the vehicle with respect to the reference line, and also tell the displacement between the first marked point and the drawing start point, for example. It is therefore possible to set the position of the vehicle at the drawing start point and correct the direction of the vehicle to the reference line direction.
The left drive wheel drive state calculator 47 and the right drive wheel drive state calculator 48 calculate and set the drive states of the left and right drive wheels 3L and 3R necessary for achieving the movement locus of the left and right drive wheels 3L and 3R that has been set at the straight line drawing portion 41, the curve line drawing portion 42, and the design pattern drawing portion 45, and then output the control signals to drivers 36L and 36R, while the drive state sensors 40L and 40R are monitoring the drive states of the left and right drive wheels driving motors 4L and 4R, respectively.
The drawing circular disc state calculator 49 calculates the wear status of the drawing circular disc 12 based upon the rotation angle sensor 21 arranged at the swing shaft 18 of the drawing mechanism case 17. According to the present embodiment, as described above, since the aluminum powders of the drawing circular disc 12 are used for drawing, the diameter of the drawing circular disc 12 will get smaller gradually. As the diameter of the drawing circular disc 12 gets smaller gradually, the drawing mechanism case 17 will face down gradually when the outer circumference of the drawing circular disc 12 is in contact with the road surface and the rotation angle of the drawing mechanism case 17 rotating around the swing shaft 18 will change. Hence, the drawing circular disc state calculator 49 calculates the outer diameter of the drawing circular disc 12 with the use of the rotation angle of the drawing mechanism case 17 sensed by the rotation angle sensor 21 when the drawing circular disc 12 is in contact with the road surface, and then calculates the wear status.
Subsequently, the control signals are output to the driver 37 to make the outer circumferential velocity of the drawing circular disc 12 always constant at the time of marking in response to the wear status of the drawing circular disc 12 that has been calculated, that is, in response to the change in the outer diameter so as to control the drive state of the drawing circular disc rotation motor 13. Also, when the wear status of the drawing circular disc 12 that has been calculated reaches or becomes close to the limit, the fact is output to the data output portion 102 and displayed on the display portion 103.
Incidentally, according to the above embodiment, there has been described an example of separately providing the drawing circular disc rotation motor for rotating the drawing circular disc 12 and the drawing mechanism moving up-and-down motor for moving up and down the drawing mechanism case 17. However, it is possible to employ only one motor instead of the two motors. In other words, as illustrated in FIG. 8A to FIG. 8D, a swing shaft 21 for swinging the drawing mechanism case 17 up and down is inserted into the drawing mechanism case 17. One-way clutches 51, which work only when the drawing mechanism case 17 is rotated upwardly, that is, only when a motor for drawing mechanism 52 composed of a step motor rotates counterclockwise in FIG. 8B, are interposed between the swing shaft and the drawing mechanism case 17. The swing shaft 21 is made to rotate in forward and reverse directions by the motor for drawing mechanism 52 by use of a pulley 53 and a belt 54, and a pulley 55 and a belt 56 connect the swing shaft 21 and the rotation shaft of the drawing circular disc 12. There is provided a proximity switch 57 at an upper rotation limit position above the drawing mechanism case 17.
In FIG. 8B, for example, when the motor for drawing mechanism 52 rotates clockwise, the swing shaft 21 rotates in the same direction and the drawing mechanism case 17 rotates downwardly. However, when the drawing circular disc 12 comes into contact with the road surface as illustrated in FIG. 8D, the one-way clutch 51 will not work and the drawing mechanism case 17 will not rotate downwardly any more. Meanwhile, since the drawing circular disc 12 is coupled to the motor for drawing mechanism 52 and keeps rotating, it is possible to draw the marking on the road surface. From this state, when the motor for drawing mechanism 52 is made to rotate counterclockwise, the swing shaft 21 rotates in the same direction. The one-way clutch 51 works and the drawing mechanism case 17 rotates upwardly. When the drawing mechanism case 17 arrives at the upper rotation limit position, the proximity switch 57 begins operating. This operation stops the motor for drawing mechanism 52.
In such a case, as described in the above embodiment, a rotation angle sensor may be provided in the vicinity of the swing shaft 51 so that the wear status of the drawing circular disc 12 may be sensed with the rotation angle of the drawing mechanism case 17. However, for example, since the drawing mechanism case 17 begins rotating upwardly as soon as the motor for drawing mechanism 52 is caused to rotate counterclockwise, it is made possible to acquire the rotation angle of the drawing mechanism case 17 by use of the number of steps from the time when the motor for drawing mechanism 52 composed of a step motor is caused to rotate counterclockwise to the time when the motor for drawing mechanism 52 is caused to stop by the operation of the proximity switch 57. With the rotation angle, it is made possible to sense the wear status of the drawing circular disc 12. This case also results in sensing of the wear status of the drawing circular disc 12 by use of the state where the drawing circular disc 12 is in contact with the road surface.
In addition, the method of drawing markings on the road surfaces with the use of the marking device 11 is not limited to the above described embodiments. As examples, there are methods of adhering powders of titanium oxide to the road surfaces, employed at present, and methods of spraying titanium dioxide solution onto the road surfaces. Furthermore, there are methods of spraying liquid such as ink, coating material, or the like, methods of spraying powders of calcium carbonate or the like, and methods of applying the liquid or powers, which are also applicable.
Moreover, by use of the above marking device, the vehicle-type drawing apparatus according to the present invention is applicable to anything as far as the markings are drawn on a drawing object of a relatively flat surface, in addition to the road surfaces. It is possible to draw markings on an open space in a park or ground, a roof of a building, a floor of a room, the bottom surface of a swimming pool without water, the bottom surface of a skating rink without ice, on the surface of ice, snowfield, and the like. Further, as the apparatus is downsized, it is made possible to draw markings on the surface of a table or desk, for example. An advantage of the vehicle-type drawing apparatus according to the present invention is that there is no limit in the size of the drawing area. As far as it is relatively flat, it is possible to draw markings on a drawing area no matter how it may be wide.
In fact, any rattling or inclination in the drawing object will displace the position of the vehicle-type drawing apparatus itself. This causes a possibility of hindering accurate drawing. In such a case, the reference point is set on the surface of the drawing object such as a road surface. The position of the apparatus is adjusted by detecting the reference point by use of a detector such as, for example, a laser radar or detecting the inclination by use of an inclination sensor. It is therefore possible to continue accurate drawing.

Claims

A vehicle-type drawing apparatus for drawing a line or a design pattern on a drawing obj ect that is relatively flat, the apparatus comprising:
two drive wheels that are provided on a same wheel shaft, that are rotatable in same directions or in reverse directions, and that are driven respectively;

a driven wheel that is arranged at a position apart from an intermediate portion between the two drive wheels by a given distance in a direction perpendicular to the wheel shaft, and that is rotatable in a free direction with respect to the drawing object;

a marking device that is arranged at an intermediate portion of the two drive wheels and that is capable of marking the line or the design pattern on the drawing object; and

a controller that causes the marking device to draw the line or the design pattern on the drawing object by marking the line or the design pattern on the drawing object, while controlling drive states of the two drive wheels.
The vehicle-type drawing apparatus according to claim 1, wherein when seen in a plan view, the gravity center of the entire vehicle-type drawing apparatus is made to locate at a position that is apart from the intermediate portion between the two drive wheels by a given distance to the driven wheel side, and that is lower than the wheel shaft of the two drive wheels.
The vehicle-type drawing apparatus according to claim 1 or claim 2, further comprising drive state sensors that sense drive states of the two drive wheels, respectively,
wherein the controller calculates information on a position of the vehicle-type drawing apparatus from the drive states of the two wheel shafts that have been sensed by the drive state sensors.
The vehicle-type drawing apparatus according to claim 3, further comprising an antiskid material provided at the two drive wheels.
The vehicle-type drawing apparatus according to claim 3 or claim 4, wherein the driven wheel is a ball.
The vehicle-type drawing apparatus according to any one of claims 1 to 5, wherein the marking device brings a metallic circular disc that is rotating into contact with the drawing object to mark the line or the design pattern on the drawing object with metallic powders of the metallic circular disc.
The vehicle-type drawing apparatus according to claim 6, wherein the metallic circular disc is made of aluminum.
The vehicle-type drawing apparatus according to claim 6 or claim 7, wherein the controller includes a drawing circular disc state calculator that detects a wear status of the metallic circular disc from the state where the metallic circular disc is in contact with the drawing object.
The vehicle-type drawing apparatus according to claim 8, wherein the drawing circular disc state calculator controls a rotation state of the metallic circular disc to make an outer circumferential velocity constant from the wear status of the metallic circular disc.
The vehicle-type drawing apparatus according to any one of claims 1 to 9, further comprising a touch sensor that senses any touch from the exterior,
wherein the controller stops drawing in the event that the touch sensor senses any touch from the exterior.
The vehicle-type drawing apparatus according to any one of claims 6 to 10, wherein cooling air for cooling down the controller is supplied to a drive system of the two drive wheels and a drive system of the metallic circular disc, and is then blown out of the wheel shaft of the two drive wheels and a rotation shaft of the metallic circular disc to the exterior.
The vehicle-type drawing apparatus according to any one of claims 1 to 11,
wherein the controller further includes a curve line drawing portion that draws a curve line on the drawing object, and
wherein the curve line drawing portion includes a data input curve line drawing portion that draws the curve line according to a curvature factor or a curvature radius of the drawing object that has been input, and a circular arc interpolation curve line drawing portion that performs arc interpolation on locations of three points on the drawing object that have been input and then draws the curve line.
The vehicle-type drawing apparatus according to any one of claims 1 to 12,
wherein the controller further includes a design pattern drawing portion that draws the design pattern on the drawing object, and
wherein the design pattern drawing portion includes a vehicle direction calculation corrector that calculates a direction that the vehicle faces from positions of two points that have been marked on a straight line on the drawing object and then corrects the direction.