Abstract:
It is an object to provide a self-propelled cleaner which facilitates restricting the raising of the cost of the self-propelled cleaner and can positively clean uncleaned areas. The self-propelled cleaner is constructed in such a manner to calculate the minimum of values (L) obtained by using the following equation (1), from present coordinates (Xc, Yc) of a place where a body has been situated, and coordinates (Xn, Yn) of uncleaned areas stored by a mapping operation, specify an uncleaned area relating to the value (L) that is the minimum, causes the body to be traveled to the uncleaned area, and cleans the uncleaned area. 
 
 L =( Xc−Xn )2+( Yc−Yn )2  Equation (1).

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a self-propelled cleaner that comprises a body provided with a cleaner mechanism, and a driving mechanism for realizing steering and driving of the body.  
         [0003]     2. Description of the Prior Art  
         [0004]     Hitherto, there is known a self-propelled cleaner that comprises a body provided with a cleaner mechanism, and a driving mechanism for realizing steering and driving of the body, and that can clean the interior of a room while self-traveling. The self-propelled cleaner is constructed such that the self-propelled cleaner searches an area of the room interior in which it is not traveled, namely, an uncleaned area of the room interior, causes the body of the self-propelled cleaner to be traveled to the uncleaned area of the room interior, and cleans the uncleaned area (see Japanese Patent Application Laid-Open Nos. Sho. 61-245215, 2004-33340, and 2000-39917).  
         [0005]     With such a self-propelled cleaner, it is possible to clean the room interior everywhere, without allowing uncleaned areas of the room interior to remain uncleaned.  
         [0006]     However, the above-mentioned Japanese Patent Application Laid-Open Nos. Sho. 61-245215, 2004-33340 and 2000-39917 do not disclose a concrete method for searching the uncleaned areas. In the event that a plurality of uncleaned areas are to be cleaned, how to cause the body to arrive at the uncleaned areas is an important factor that is required in order that idle traveling of the body can be avoided and consumption of a battery for the self-propelled cleaner can be saved. However, in order to set the order of cleaning of the uncleaned areas and travel routes of the body, it is necessary to design an arithmetic operation circuit, such as a CPU or the like, in such a manner that it has a high-performance, and also provide a RAM that serves as a work area and has a high-performance, thus raising the cost of the self-propelled cleaner.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention has been made with a view to overcoming the foregoing problems of the prior art self-propelled cleaners. It is therefore an object of the present invention to provide a self-propelled cleaner that facilitates restraining of a substantial cost and can positively carry out cleaning of uncleaned areas.  
         [0008]     In order to attain the above-mentioned object, in accordance with the present invention, there is provided a self-propelled cleaner that comprises a body provided with a cleaner mechanism, a driving mechanism for realizing steering and driving of the body, a mapping means for mapping cleaned areas as cleaning-completed area and mapping areas, not to be cleaned, as uncleaned area, while controlling the cleaner mechanism and the driving mechanism and causing the body to be traveled, the mapping means being designed in such a manner to assume an interior of a room, that is to be cleaned, as a plane-coordinate system of an X-axis and a Y-axis, take areas to be cleaned by the body at the time of stopping of the body, as unit areas, store coordinates of the cleaning-completed areas and coordinates of the uncleaned areas, and an uncleaned area-searching means for calculating the minimum of values (L) obtained by using the following equation (1), from present coordinates (Xc, Yc) of a place where the body has be situated, and coordinates (Xn, Yn) of the uncleaned areas stored by the mapping means, and searching an uncleaned area that is generally close to a present location of the body. 
 
 L =( Xc−Xn )2+( Yc−Yn )2  Equation (1). 
 
         [0009]     In the self-propelled cleaner of the present invention that is constructed as described above, the drive mechanism realizes the steering and driving of the body when the cleaner mechanism provided at the body is to carry out cleaning. Moreover, the self-propelled cleaner is provided with the mapping means that maps areas having been cleaned, as cleaning-completed areas and maps areas having not been cleaned, as uncleaned areas, while controlling the cleaner mechanism and the driving mechanism, and causing the body to be traveled while cleaning. That is, a route in which the body of the self-propelled cleaner has been traveled is mapped as a cleaning-completed area, and a route in which the body is not yet traveled is mapped as an uncleaned area.  
         [0010]     The mapping means is designed in such a manner to assume an interior of a room, that is to be cleaned, as a plane-coordinate system of an X-axis and a Y-axis, take ranges to be cleaned by the body at the time of stopping of the body, as unit areas, and store coordinates of the cleaning-completed areas and coordinates of the uncleaned areas. That is, the cleaning-completed areas and the uncleaned areas are stored as, for example, coordinates such as (1, 1) and (2, 4), whereby they are mapped.  
         [0011]     Moreover, the self-propelled cleaner is provided with the uncleaned area-searching means for calculating the minimum of values (L) obtained by using the above-described equation (1), from present coordinates (Xc, Yc) of a place where the body has been present, and coordinates (Xn, Yn) of the uncleaned areas stored by the mapping means, and searching an uncleaned area that is generally close to a present location of the body. By such a construction, it is possible to minimize a travel distance of the body from the present location of the body to the uncleaned area by searching the unleaned area generally close to the present location of the body and cleaning the uncleaned area and thereafter searching an uncleaned area generally close the body. Therefore, it is possible to prevent idle traveling of the body and restrict the consumption of the battery. Moreover, it is possible to search the uncleaned area that is generally close to the body, by carrying out relatively simple arithmetic operation in which the values (L) are calculated by the above-mentioned equation (1) from the coordinates of the present location of the body and the coordinates of the uncleaned areas, and the minimum of the values (L) is calculated. Therefore, a high-performance CPU, a high-performance memory and the like are not required and it is possible to restrain the raising of the cost of the self-propelled cleaner.  
         [0012]     According to the present invention described above, it is possible to positively carry out cleaning of uncleaned areas while prevent idle traveling of the body and restraining the consumption of the battery, and restrain the raising of the cost of the self-propelled cleaner.  
         [0013]     A self-propelled cleaner according to a preferred embodiment of the present invention is provided with an uncleaned area-cleaning means that causes the body to be traveled to the uncleaned area that is generally close to the present location of the body and has been searched by the uncleaned area-searching means, and causes the cleaner mechanism to clean the uncleaned area.  
         [0014]     The self-propelled cleaner according to the embodiment of the present invention that is constructed as described above can positively carry out cleaning of the uncleaned area after the body arrives at the uncleaned area.  
         [0015]     A self-propelled cleaner according to a preferred embodiment of the present invention is provided with a deleting means for deleting from the mapping means data on the uncleaned area that has been cleaned by the uncleaned area-cleaning means.  
         [0016]     In the self-propelled cleaner according to the embodiment of the present invention, data on the uncleaned areas having been cleaned once are deleted, so that it is possible to prevent repeated cleaning of the uncleaned areas having been once cleaned and efficiently carry out cleaning of the room interior.  
         [0017]     A self-propelled cleaner according to a preferred embodiment of the present invention is provided with an obstacle sensing means for sensing obstacles in front of the body and on right and left sides of the body; wherein the mapping means is designed in such a manner to store coordinates of places where the obstacles are present when the obstacles are present in front of the body and on the right and left sides of the body, to thereby map the places as obstacle areas.  
         [0018]     In the self-propelled cleaner constructed as described above, it is possible set a route of the body to the uncleaned area, on the basis of the coordinates of the obstacles that have been stored.  
         [0019]     In the self-propelled cleaner, the obstacle sensing means includes an ultrasonic sensor for sensing the obstacles in front of the body.  
         [0020]     In this self-propelled cleaner, it is possible to sense the obstacles in front of the body by receiving ultrasonic waves reflected by the obstacles in front of the body.  
         [0021]     In the self-propelled cleaner, the obstacle sensing means includes sidewall sensors for sensing the obstacles on the right and left sides of the body, the sidewall sensors having infrared ray-emitting sections and infrared ray-receiving sections.  
         [0022]     In this self-propelled cleaner, it is possible to sense the obstacles on the left and right sides of the body by detecting infrared rays reflected by the obstacles on the left and right sides of the body. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]     The above-mentioned object, other objects and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference designators denote like or corresponding parts throughout, wherein:  
         [0024]      FIG. 1  is a schematic perspective view of an appearance of a self-propelled cleaner according to the present invention;  
         [0025]      FIG. 2  is a schematic bottom view of the self-propelled cleaner shown in  FIG. 1 ;  
         [0026]      FIG. 3  is a schematic block diagram illustrating a construction of the self-propelled cleaner shown in  FIGS. 1 and 2 ;  
         [0027]      FIG. 4  is a schematic flowchart exhibiting a mapping operation;  
         [0028]      FIG. 5  is a schematic view illustrating the condition of the interior of a room and a travel route of a body;  
         [0029]      FIG. 6  is a view illustrating one example of mapping data stored in a RAM when the mapping operation is carried out;  
         [0030]      FIG. 7  is a schematic flowchart exhibiting a cleaning operation for cleaning uncleaned areas;  
         [0031]      FIG. 8  is a view illustrating another example of the mapping date; and  
         [0032]      FIG. 9  is a view illustrating still another example of the mapping data. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0033]     Now, embodiments according to the present invention will be discussed hereinafter in the following order:  
         [0034]     (1) an appearance of a self-propelled cleaner;  
         [0035]     (2) an internal construction of the self-propelled cleaner;  
         [0036]     (3) an operation of the self-propelled cleaner; and  
         [0037]     (4) various variants.  
         [0038]     (1) The Appearance of the Self-Propelled Cleaner:  
         [0039]      FIG. 1  is a perspective view showing the appearance of the self-propelled cleaner according to the present invention.  FIG. 2  is a bottom view of the self-propelled cleaner shown in  FIG. 1 . Incidentally, a direction indicated in  FIG. 1  by an arrow is an advance direction of the self-propelled cleaner. As shown in  FIG. 1 , the self-propelled cleaner  10  according to the present invention includes a body BD of a substantially cylindrical shape and two drive wheels  12 R,  12 L (see  FIG. 2 ) provided at a bottom side of the self-propelled cleaner. By driving of the drive wheels  12 R,  12 L separately, the self-propelled cleaner  10  can be advanced, retreated and turned. Furthermore, at a center portion of the front side of the body BD, an infrared CCD sensor  73  serving as an image picking-up sensor is provided.  
         [0040]     Moreover, seven ultrasonic sensors  31  ( 31   a - 31   g ) that act as an obstacle detecting means for sensing an obstacle ahead of the body BD are provided at a portion of the body BD which is below the infrared CCD sensor  73 . The ultrasonic sensors  31  comprise dispatching sections for sending supersonic waves and receiver sections for receiving the supersonic waves that are provided by the ultrasonic sensors  31 , reflected by a forward wall and then returned. The ultrasonic sensors  31  can calculate a distance of the body BD to the wall from a time that is required from the providing of the supersonic waves by the dispatching sections to the receiving of the supersonic waves by the receiver sections. Of the seven ultrasonic sensors  31 , the ultrasonic sensor  31   d  is provided at the center portion of the front side of the body BD, the ultrasonic sensors  31   a ,  31   g  are symmetrically arranged at a left side and a right side, respectively, the ultrasonic sensors  31   b ,  31   f  are symmetrically arranged at the left side and the right side, respectively, and the ultrasonic sensors  31   c ,  31   e  are symmetrically arranged at the left side and right side, respectively.  
         [0041]     Moreover, pyroelectric sensors  35  ( 35   a ,  35   b ) are provided at the left side and right side of the front side of the body BD. The pyroelectric sensors  35   a ,  35   b  sense infrared rays generated from the human body and can detect the human who is present in the vicinity of the body BD. Incidentally, though pyroelectric sensors  35  ( 35   c ,  35   d ) (see  FIG. 3 ) are not shown in  FIG. 1 , they are provided at left and right sides of a rear side of the body BD. Thus, the pyroelectric sensors  35  are constructed so as to have a sensing range of 360 degrees around the body BD.  
         [0042]     As shown in  FIG. 2 , the two drive wheels  12 R,  12 L are provided at the left and right sides of the bottom of the body BD. Moreover, three supplementary wheels  13  are provided at a forward side of the bottom of the body BD (on the side of the advance direction). Furthermore, step sensors  14  for detecting unevenness of a room floor surface and steps of the room floor surface are provided at the upper right-hand region, the lower right-hand region, the upper left-hand region and the lower left-hand region of the bottom of the body BD. A main brush  15  is provided at a region of the bottom of the body BD that is lower than the center portion of the bottom of the body BD. The main brush  15  is driven by a main brush motor  52  (not shown in  FIG. 2  but shown in  FIG. 3 ) and can sweep dirt and/or dust on the room floor surface. Moreover, an opening of a portion of the body BD to which the main brush  15  is attached is a suction inlet. The dirt and/or dust is adapted to be sucked into the suction inlet while being swept by the main brush  15 . Furthermore, side brushes  16  are provided at the upper right-hand region and the upper left-hand region of the bottom of the body BD, respectively.  
         [0043]     Incidentally, though the self-propelled cleaner  10  according to the present invention is provided with various sensors in addition to the ultrasonic sensors  31 , the pyroelectric sensors  35  and the step sensors  14  that are shown in  FIGS. 1 and 2 , the various sensors other than the sensors  31 ,  35 ,  14  will be discussed in greater detail hereinafter with reference to  FIG. 3 .  
         [0044]     (2) The Internal Construction of the Self-Propelled Cleaner:  
         [0045]      FIG. 3  is a schematic block diagram illustrating the construction of the self-propelled cleaner shown in  FIGS. 1 and 2 . As shown in  FIG. 3 , a CPU  21  serving as a control section, a ROM  23 , and a RAM (storage region)  22  are coupled to the body BD through a bus  24 . The CPU  21  uses the RAM  22  as a work area and carries out various controls according to a control program and various parameter tables which are stored in the ROM  23 .  
         [0046]     The body BD is provided with a battery  27 . The CPU  21  is adapted to be able to monitor a residual quantity of the battery  27  through a battery monitoring circuit  26 . Moreover, the battery  27  is provided with a charging terminal  27   a  that is to be used for charging of the battery  27  by a charger device  100  which will be discussed in greater detail hereinafter. An electrical supply terminal  101  of the charger device  100  is operatively coupled to the charging terminal  27   a , whereby the charging is carried out. The battery monitoring circuit  26  mainly monitors a voltage of the battery  27  and then detects the residual quantity of the battery  27 . Furthermore, the body BD has a speech circuit  29   a  that is coupled to the bus  24 . A speaker  29   b  generates voice according to speech signals that are produced in the speech circuit  29   a.    
         [0047]     As discussed above, the body BD is provided with the ultrasonic sensors  31  ( 31   a - 31   g ) serving as distance measuring devices, the pyroelectric sensors  35  ( 35   a - 35   d ) acting as human body sensors, and the step sensor  14  (see  FIGS. 1 and 2 ). Moreover, the body BD is provided with sidewall sensors  36 R,  36 L for detecting sidewalls of the room, as some of the other sensors that are not shown in  FIGS. 1 and 2 . In the illustrated example, the sidewall sensors  36 R,  36 L are infrared sensors that comprise light emitting sections for emitting infrared rays and receiver sections for receiving the infrared rays. However, as the sidewall sensors, there may be employed, for example, passive sensors, ultrasonic sensors or the like. Furthermore, the body BD is provided with a gyro sensor  37  as one of the above-mentioned other sensors. The gyro sensor  37  comprises an angular velocity sensor  37   a  for detecting a change in an angular velocity due to change in the advance direction of the body BD, and can detect an angle of a direction to which the body BD is directed, by carrying out multiplying of a sensor output value detected by the angular velocity sensor  37   a.    
         [0048]     The self-propelled cleaner  10  according to the present invention is provided with motor drivers  41 R,  41 L, drive wheel motors  42 R,  42 L, and an unshown gear unit arranged between the drive wheel motors  42 R,  42 L and the above-mentioned drive wheels  12 R,  12 L, as a driving mechanism. When the body BD is to be turn-traveled, the rotational direction and rotation angle of the drive wheel motors  42 R,  42 L are particularly controlled by the motor drivers  41 R,  41 L. The respective motor drivers  41 R,  41 L output driving signals corresponding to control signals from the CPU  21 . Incidentally, as the gear unit and the drive wheels  12 R,  12 L, there may be employed various gear units and drive wheels. The driving may be carried out by causing round-shaped rubber tires to be driven or causing an endless belt to be driven.  
         [0049]     Moreover, rotary encoders (not shown) are integrally attached to the drive wheel motors  42 R,  42 L. It is possible to precisely detect actual rotational direction and rotation angle of the drive wheels from outputs of the rotary encoders. Incidentally, the rotary encoders may not be attached directly to the drive wheel motors  42 R,  42 L and a freely rotatable driven wheel may be provided in the vicinity of the drive wheels. In this case, a rotating amount of the driven wheel is fed back, whereby actual rotating amounts of the drive wheels can be detected even if slipping of the drive wheels occurs. Furthermore, an acceleration sensor  44  detects accelerations in three XYZ-axial directions, and then outputs the detection results.  
         [0050]     A cleaner mechanism of the self-propelled cleaner  10  according to the present invention comprises the two side brushes  16  provided at the bottom of the body BD (see  FIG. 2 ), the main brush  15  provided at the central portion of the bottom of the body BD (see  FIG. 2 ), and a suction fan (not shown) for sucking dirt and/or dust swept by the main brush  15  and facilitating storing of the dirt and/or dust in a dust box. The main brush  15  is adapted to be driven by the main brush motor  52 . Also, the suction fan is adapted to be driven by a suction motor  55 . Motor drivers  54 ,  56  are adapted to supply driving power to the main brush motor  52  and the suction motor  55 , respectively. The cleaning performed by the main brush  15  is suitably judged and controlled by the CPU  21 , according to a condition of the floor surface, a condition of the battery and instructions from the user.  
         [0051]     Moreover, the body BD has a wireless LAN module  61 . The CPU  21  is adapted to be able to communicate with an external LAN by radio according to a predetermined protocol. On the condition that there are unshown access points, the wireless LAN module  61  shall be governed by an environment in which the access points can be connected to an external wideband net work (for example, an internet) through routers or the like. Therefore, it is possible to carry out transmit-receive of usual mail through the internet and reading of web site. Incidentally, the wireless LAN module  61  is comprised of a standardized card slot, a standardized wireless-LAN card, which is connected to the slot, and the like. Of course, a different standardized card can be connected to the card slot.  
         [0052]     Moreover, the body BD is provided with an infrared CCD sensor  73 , and an infrared ray source  72 . An image picking-up signal that is generated in the infrared CCD sensor  73  is transmitted through the bus  24  to the CPU  21  which carries out various processes with respect to the image picking-up signal. The infrared CCD sensor  73  has an optical system that can pick up an image of an area in front of the body BD, and produces an electric signal according to infrared rays that are incident on a field of view that is realized by the optical system. Concretely, there are provided a plurality of photodiodes that are arranged correspondingly to respective picture elements at an image formation location that is determined by the above-mentioned optical system. The respective photodiodes produce electric signals that correspond to electrical energies of the incident infrared rays. A CCD element temporarily memorizes the electric signals that are produced for every picture elements, and produces image picking-up signals in which electric signals are continued for the respective picture elements. Then, the produced image picking-up signals are suitably outputted to the CPU  21 .  
         [0053]     (3) The Operation of the Self-Propelled Cleaner:  
         [0054]     Now, the operation of the self-propelled cleaner  10  according to the present invention will be discussed hereinafter.  
         [0055]     The self-propelled cleaner  10  according to the present invention carries out cleaning while causing the body BD to be traveled and carries out a mapping operation in which cleaned areas are mapped as cleaning-completed areas, areas that are not cleaned are mapped as uncleaned areas, and areas in which obstacles are present are mapped as obstacle areas. At this time, the body BD is traveled in such a zigzag manner that when the body BD arrives at a location that is short of a forward obstacle, while being straightly advanced, the body BD is turned through 90 degrees, traveled by a predetermined distance, thereafter turned again in the same direction through 90 degrees, and straightly advanced again until the body BD arrives at the location that is short of the forward obstacle.  
         [0056]     Moreover, when the above-mentioned mapping operation is carried out and the body BD is traveled to a terminal point, the body BD is moved to one of several uncleaned areas subjected to the mapping operation, that is an uncleaned area generally close to a present location of the body BD, and cleaning of the uncleaned area is then carried out. Such an uncleaned area-cleaning operation is continued until cleaning of all of uncleaned areas in the room interior is completed.  
         [0057]      FIG. 4  is a flowchart exhibiting a procedure for the mapping operation performed in the self-propelled cleaner  10  according to the present invention. Incidentally, the procedure for the mapping operation that is exhibited in  FIG. 4  will be discussed in conjunction with a cleaning operation for cleaning the interior of a room that is shown in  FIG. 5 .  FIG. 6  shows one example of mapping data memorized in the RAM  22  when the mapping operation is carried out. A cleaning range at the time when the body BD is stopped is approximately equal to a dimension of the body BD (30 cm×30 cm). In the mapping operation, this range is set as a unit area, a vertical direction in the room interior (a vertical direction in  FIG. 5 ) is denoted as an X-axis, and a lateral direction is denoted as a Y-axis. Coordinates of respective unit areas are in turn written into the RAM  22  or the like as the cleaning-completed areas, uncleaned areas and obstacle areas. For example, coordinates for the body BD shown in  FIG. 5  are (1, 1), coordinates for a left-hand wall W are (0, m), and coordinates for a lower wall W are (n, 0).  
         [0058]     The mapping operation is initially carried out with respect to a cleaning-completed area at a step S 100 . In this process, coordinates of a unit area for a place at which the body BD has been present are written in as a cleaning-completed area. For example, the coordinates for the body BD shown in  FIG. 5  are (1, 1) and written in as the cleaning-completed area. In  FIG. 6 , the coordinates (1, 1) are written in as the cleaning-completed area (shown with a mark “circle”).  
         [0059]     At a step S 110 , whether or not any obstacle has been present on the left side of the body BD is judged. In this process, whether or not the left sidewall-sensor  36 L senses the obstacle on the left side of the body BD is judged. In a case where it is judged that the obstacle has been present on the left side of the body BD, a mapping process for mapping the left side of the body BD as an obstacle area is carried out at a step S 120 . That is, next coordinates on the left side of coordinates of the place at which the body BD has been present are written in as an obstacle area. In  FIG. 6 , the next coordinates (0, 1) on the left side of the coordinates (1, 1) are written in as the obstacle area (shown with a mark “x”).  
         [0060]     On the other hand, when it is judged at the step S 110  that any obstacle has been not present on the left side of the body BD, a mapping process for mapping the left side of the body BD as an uncleaned area is carried out at a step S 130 . That is, next coordinates on the left side of the coordinates of the place at which the body BD has been present are written in as an uncleaned area. In  FIG. 6 , this uncleaned area is not indicated by any designator (remains blank). Incidentally, even if the coordinates are written in as the uncleaned area at the step S 130 , when the body BD travels and cleans the same area, the area is overwritten as a cleaning-completed area.  
         [0061]     When the processing of the step S 120  or S 130  is carried out, whether or not any obstacle has been present on the right side of the body BD is judged at a step S 140 . In this process, whether or not the right sidewall-sensor  36 R has detected an obstacle that has been present on the right side of the body BD is judged. When it is judged that the obstacle has been present on the right side of the body BD, a mapping process for mapping an area on the right side of the body BD as an obstacle area is carried out at a step S 150 . That is, next coordinates on the right side of the coordinates of the place at which the body BD has been present are written in as an obstacle area.  
         [0062]     On the other hand, it is judged at the step S 140  that any obstacle has not been present on the right side of the body BD, a mapping process for mapping an area on the right side of the body BD as an uncleaned area is carried out at a step S 160 . That is, next coordinates on the right side of the coordinates of the place at which the body BD has been are written as an uncleaned area.  
         [0063]     When the process of the step S 150  or S 160  is carried out, whether or not any obstacle has been present in front of the body BD is judged at a step S 170 . That is, whether or not the ultrasonic sensors  31  have sensed any obstacle in front of the body BD is judged. Incidentally, this processing is to judge whether or not any obstacle has been present at a next unit area on the forward side of the present coordinates of the body BD. This judgment is carried out by measuring a distance to the forward obstacle from the body BD by the ultrasonic sensors. For example, when the body BD has been situated at coordinates (1, 8) indicated in  FIG. 6 , whether or not any obstacle has been present at a next unit area (1, 9) on the forward side is judged.  
         [0064]     When it is judged at the step S 170  that the forward obstacle has been sensed, a mapping process for mapping an area in front of the body BD as an obstacle area is carried out at a step S 180 . That is, next coordinates on the forward side of the unit area at which the body BD has been present are written in as an obstacle area. For example, the next coordinates (1, 9) on the forward side of the coordinates (1, 8) of the body BD in  FIG. 6  are written in as an obstacle area (shown with a mark “x”).  
         [0065]     When the processing of the step S 180  is carried out, a processing for causing the body BD to be turned through 90 degrees is carried out. When this processing is completed, the body BD is then moved in parallel to the obstacle.  
         [0066]     The direction to which the body BD is turned through 90 degrees at this time is a direction in which no obstacle is present and which an uncleaned area is present.  
         [0067]     When a processing of a step S 190  is carried out or it is judged at the step S 170  that no obstacle has been present in front of the body BD, a processing for causing the body BD to be advanced is carried out at a step S 200 . In this processing, controlling of the drive motors  42 R,  42 L is carried out and the body BD is straightly-advanced by a unit area. For example, where the body BD has been present at the coordinates (1, 1), the body BD is traveled to coordinates (1, 2). Furthermore, for example, where the body BD has been situated at the coordinates (1, 8) and the 90 degrees turn of the body BD has been carried out at the sep S 190 , the body BD is moved to coordinates (2, 9).  
         [0068]     When the process of the step S 200  is carried out, whether or not the 90 degrees turn of the body BD was previously carried out is judged. In this processing, whether or not the 90 degrees turn of the body BD was carried out by the processing of the step S 190  prior to performing of the processing for causing the body BD to be straightly-advanced at the step S 200 , is judged. When it is judged at a step S 210  that the 90 degrees turn of the body BD was previously carried out, a 90 degrees turn of the body BD is again carried out at a step S 220 .  
         [0069]     On the other hand, when it is judged at the step S 210  that the 90 degrees turn of the body BD was not previously carried out, whether or not the body BD has arrived at a terminal is judged at a step S 230 . In the mapping operation, where any obstacles on the forward, left and right sides of the body have been sensed and where the body BD has arrived at a unit area in which the body was already traveled, it is judged that the body BD has arrived at the terminal. When it is judged at the step S 230  that the body BD does not yet arrive at the terminal, a processing is returned to the step S 100 . On the other hand, when it is judged at the step S 230  that the body BD has arrived at the terminal, the mapping operation is terminated.  
         [0070]     The mapping processes shown in  FIG. 4  are carried out, whereby the body BD follows a route indicated in  FIG. 5  by an arrow of a chain double-dashed line, this processing is terminated at a point E (coordinates (10, 9)) in  FIG. 5  and the body BD is stopped. Such mapping data as shown in  FIG. 6  is then prepared. Incidentally, blank portions shown in  FIG. 6  represent uncleaned areas as described above. These uncleaned areas include areas where the body BD can be actually traveled, and areas where the body can not be traveled and any obstacles have been present.  
         [0071]     Now, a cleaning operation for cleaning uncleaned areas that is carried out after the mapping processes of  FIG. 4  were carried out will be discussed hereinafter. Incidentally, a case where the point E (coordinates (10, 9)) that is the terminal of the route shown in  FIG. 5  is taken as a start point and an uncleaned area generally close to the point E is searched will be discussed in the following.  FIG. 7  is a schematic flowchart exhibiting a cleaning operation for cleaning uncleaned areas that is carried out after the mapping processes of  FIG. 4  were performed.  
         [0072]     When the cleaning process for cleaning uncleaned areas is initiated, first of all, a calculating process for calculating numeral values (L) from coordinates for respective uncleaned areas and coordinates of the present location of the body BD is carried out at a step S 300 . In this processing, for the respective coordinates (Xn, Yn) of the uncleaned areas that have been written in the mapping date shown in  FIG. 6 , calculating of the values (L) is carried out from the coordinates (Xn, Yn) and the coordinates (Xc, Yc) of the place where the body BD has been present, by using the following equation (1): L=(Xc−Xn)2+(Yc−Yn)2.  
         [0073]     When the processing of the step S 300  is carried out, a process for calculating the minimum of the values (L) is carried out at a step S 310 . That is, a process for calculating the minimum of the values (L) for the respective uncleaned areas which were calculated at the step S 300  is carried out.  
         [0074]     When the process of the step S 310  is carried out, a process for specifying an uncleaned area generally close to the body BD is carried out at a step S 320 . In this processing, an uncleaned area relating to a value (L) that was calculated as the minimum value at the step S 310  is specified as the uncleaned area generally close to the body BD.  
         [0075]     When the process of the step S 320  is carried out, a process for causing the body BD to be traveled to the uncleaned area generally close to the body BD, while carrying out mapping of obstacle areas is carried out at a step S 330 . In this processing, the process for causing the body to be traveled to the uncleaned area that was specified in the step S 320  as the uncleaned area generally close to the body BD, is carried out, and sensing of any obstacles is carried out by the sidewall sensors  36 R,  36 L and the ultrasonic sensors  31  during the traveling of the body BD. When any obstacles have been sensed, unit areas in front of the body BD and on the right and left sides of the body BD are mapped as obstacle areas. In this way, when any obstacles are present at the unit areas that were mapped as the obstacle areas prior to the initiating of the uncleaned area cleaning process, the unit areas are overwritten as the obstacle areas, whereby it is possible to correct the mapping data.  
         [0076]     When the process of the step S 330  is carried out, a cleaning process is carried out at a step S 340 . In this processing, the uncleaned area which is generally close to the body BD and at which the body BD has arrived as a result of the processing of the step S 330  is cleaned. That is, the processing of the step S 340  is carried out, whereby the cleaning of the uncleaned area is completed.  
         [0077]     When the processing of the step S 340  is carried out, a process for deleting the data on the uncleaned area is carried out at a step S 350 . That is, the data on the unleaned areas that were cleaned at the step S 330  are deleted. In this way, it is possible to prevent repeated cleaning of the uncleaned areas having been once cleaned.  
         [0078]     When the processing of the step S 350  is carried out, a process for mapping cleaning-completed areas is carried out at a step S 360 . In this processing, coordinates of the uncleaned areas having been deleted at the step S 340  are written in as cleaning-completed areas.  
         [0079]     When the processing of the step S 360  is carried out, whether or not all the uncleaned areas have been cleaned is judged at a step S 370 . In the event that it is judged that the uncleaned areas all have not been cleaned, a process is returned to the step S 300 . On the other hand, where it is judged that all the uncleaned areas have been cleaned, the uncleaned area cleaning process is terminated.  
         [0080]     Referring now to  FIGS. 8 and 9 , embodiments for performing the uncleaned area cleaning process shown in  FIG. 7  will be discussed hereinafter. First of all, the terminal (coordinates (10, 9)) of the travel route of the body BD that is shown in  FIG. 5  is taken as the start point and, regarding the several uncleaned areas that have been written in the mapping data, calculating of the values (L) is carried out using the above-mentioned equation (1) (at the step S 300 ). The minimum of the values (L) having been calculated regarding the respective uncleaned areas is calculated (at the step S 310 ), and the uncleaned area generally close to the place at which the body BD has been present is specified (at the step S 320 ). Incidentally, in  FIG. 8 , an uncleaned area in which the value (L) from the start point becomes the minimum is the coordinates (11, 10) and the coordinates (11, 8). However, the body BD can not be traveled to a unit area relating to the coordinates, so that the uncleaned area is excluded. Coordinates (10, 9) indicated in  FIG. 8  by a number  1  are specified as an uncleaned area generally close to the body BD.  
         [0081]     Thereafter, a process for causing the body BD to be traveled to the uncleaned area specified as the uncleaned area generally close to the body BD is carried out while carrying out a process for mapping obstacle areas. In  FIG. 8 , the travel route of the body BD is indicated by an arrow of a chain double-dashed line. When the body BD has arrived at the coordinates (10, 9) indicated by the number  1 , obstacles that are present at unit areas of coordinates (11, 10) and coordinates (10, 6) are sensed and mapped as obstacle areas. Thereafter, the uncleaned area which is generally close to the place at which the body BD has arrived is cleaned (at the step S 340 ), the data on the uncleaned area are deleted (at the step S 350 ), and the area is mapped as a cleaning-completed area (at the step S 360 ).  
         [0082]     When the above-mentioned process for carrying out the cleaning of the uncleaned area generally close to the body BD is carried out, a point (coordinates (10, 7)) which is indicated in  FIG. 9  by a number  1  and has been subjected to the uncleaned area cleaning process is taken as a present location, and searching and cleaning of uncleaned areas are again carried out. In this case, the body BD is traveled along a route indicated in  FIG. 9  by an arrow of a chain double-dashed line and arrives at a point (coordinates (10, 5)) indicated in  FIG. 9  by a number  2 , and cleaning of the uncleaned area is carried out.  
         [0083]     (4) Various Variants  
         [0084]     While the case where the infrared CCD sensor is employed as the image picking-up sensor is described in the foregoing, the image picking-up sensor that is employed in the self-propelled cleaner according to the present invention is not limited to the infrared CCD sensor. For example, any camera which is photosensitive to light of predetermined color (for example, blue light) may be employed as the image picking-up sensor. In this case, a means for emitting light of the predetermined color (for example, a blue light emitting diode (LED) lamp) is employed as a light emitting device.  
         [0085]     Moreover, while the case where the mapping of the uncleaned areas is carried out each time the body BD arrives at the next unit areas is described in the foregoing, the embodiments of the present invention may be constructed such that only the obstacle areas and cleaning-completed areas are mapped during the traveling of the body BD and unit areas that have not been subjected to the mapping process at the time when the body BD arrives at the terminal are collectively mapped as uncleaned areas.  
         [0086]     (5) Summary:  
         [0087]     As described above, the self-propelled cleaner  10  according to the present invention is constructed such that it carries out the calculating of the minimum of the values (L) from the coordinates (Xc, Yc) of the place at which the body BD has been present, and the coordinates (Xn, Yn) that are stored by carrying out the mapping process, by using the following equation (1), specifies the uncleaned area relating to the value (L) that is taken as the minimum, causes the body BD to be traveled to the uncleaned area, and carries out the cleaning of the uncleaned area. Therefore, it is possible to minimize a travel distance of the body BD from the present location of the body BD to the uncleaned area and possible to restrict the consumption of the battery. Moreover, it is possible to search the uncleaned area, that is generally close to the body BD, by carrying out simple arithmetic operation, so that a high-performance CPU, a high-performance memory and the like are not required and it is possible to restrain the raising of the cost of the self-propelled cleaner. 
 
 L =( Xc−Xn )2+( Yc−Yn )2  equation (1). 
 
         [0088]     It should be noted that the terms and expressions having been employed herein are used as terms of description, not of limitation. In the use of such terms and expressions, there is no intention of excluding any equivalents of the features illustrated and described or portions thereof. However, it is recognized that various modifications are possible within the scope of the invention claimed.