Patent Publication Number: US-2013228198-A1

Title: Cleaning system and control method thereof

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/606,106 filed on Mar. 2, 2012, and Taiwan Patent Application No. 101127709, filed on Aug. 1, 2012, the entirety of which is incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a cleaning system, and more particularly, to a cleaning system utilizing a cleaning robot. 
     2. Description of the Related Art 
     Cleaning floors take a lot of time. To reduce the time for cleaning a floor, many cleaning devices have been developed, such as a broom, a mop and so forth. However, the cleaning devices must be manually operated for cleaning. Thus, conventional cleaning devices are inconvenient. 
     With technological development, many electronic devices have been developed, such as robots. Taking a cleaning robot as an example, the cleaning robot can autonomously execute a cleaning action. A user is not required to manually operate the cleaning robot to clean a floor. Thus, the cleaning robot has gradually replaced conventional cleaning devices. Generally, a conventional method of a cleaning robot utilizes a virtual wall to limit the traveling path of the cleaning robot and utilizes a docking station for charging the cleaning robot. However, if the cleaning robot cannot obtain an accurate position of the virtual wall or the docking station, the cleaning robot may collide with the virtual wall or cannot immediately connect to the docking station. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with an embodiment, a cleaning system comprises a guiding object and a cleaning robot. The guiding object comprises a magnet to form a magnetic field. The cleaning robot comprises an operation module, a first sense module and a control module. The operation module performs a cleaning action and a moving action according to a control signal. The first sense module generates a first sensed signal according to the magnetic field. The control module generates the control signal to adjust an efficiency of at least one of the cleaning action and the moving action according to the first sensed signal. 
     An exemplary embodiment of a control method for a cleaning robot is described in the following. A magnet module is disposed in a guiding object to form a magnetic field. The magnetic field is sensed to generate a sensing result and a first sensed signal is generated according to the sensing result. An efficiency of at least one of a cleaning action and a moving action is controlled according to the first sensed signal. 
     A detailed description is given in the following embodiments with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be more fully understood by referring to the following detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG. 1  is a schematic diagram of an exemplary embodiment of a cleaning system 
         FIG. 2  is a schematic diagram of an exemplary embodiment of a control method of the invention; and 
         FIG. 3  is a schematic diagram of another exemplary embodiment of a control method of the invention 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims. 
       FIG. 1  is a schematic diagram of an exemplary embodiment of a cleaning system. The cleaning system  100  comprises a guiding object  110  and a cleaning robot  130 . In this embodiment, the guiding object  110  comprises a magnet module  111  to form a magnetic field. In one embodiment, the magnet module  111  comprises at least one NdFeB magnet  113 . 
     The invention does not limit the function of the guiding object  110 . In this embodiment, the guiding object  110  is capable of guiding the cleaning robot  130 . In one embodiment, the guiding object  110  is a virtual wall to limit the traveling path of the cleaning robot  130 . In another embodiment, the guiding object  110  is a docking station for charging the cleaning robot  130 . 
     The cleaning robot  130  comprises an operation module  131 , a sense module  132  and a control module  133 . The operation module  131  performs a cleaning action and a moving action according to a control signal. The invention does not limit the circuit structure of the operation module  131 . Any element can be contained in the operation module  131 , as long as the element is capable of performing a cleaning action or a moving action. In this embodiment, the operation module  131  comprises a cleaning brush  134 , wheels  135 ,  136 , and a suction aperture  137 . The cleaning brush  134  and the suction aperture  137  execute a cleaning action. The wheels  135  and  136  execute a moving action. 
     The sense module  132  generates a sensed signal according to the magnetic field generated by the magnet module  111 . In this embodiment, the sense module  132  is disposed at a lateral side of the cleaning robot  130 , but the disclosure is not limited thereto. In other embodiments, the sense module  132  can be disposed at any position of the cleaning robot  130 , as long as the sense module  132  is capable of sensing the magnetic field. Additionally, the invention does not limit the circuit structure of the sense module  132 . In one embodiment, the sense module  132  comprises at least one of a compass sensor, a Hall sensor, a gyroscope and a g sensor. 
     The control module  133  generates the control signal to adjust an efficiency of at least one of the cleaning action and the moving action according to the first sensed signal. 
     For example, the control module  133  controls the speed and the direction of the wheels  135  and  136  to stop or start the cleaning robot  130  or adjust the moving speed or the traveling path of the cleaning robot  130  according to the sensing signal generated by the sense module  132 . In one embodiment, the moving speed of the cleaning robot  130  may be increased or reduced. In other embodiments, the control module  133  controls the cleaning robot  130  to rotate or cruise. 
     In addition, the control module  133  controls the speed of the cleaning brush  134 , and the suction or the air flow of the suction aperture  137  to adjust the efficiency of the cleaning action of the cleaning robot  130  according to the sensed signal generated by the sense module  132 . 
     In this embodiment, when the cleaning robot  130  approaches the guiding object  110 , the sense module  132  can sense a magnetic field and the magnetic field is strong. Contrarily, when the cleaning robot  130  leaves the guiding object  110 , no magnetic field can be sensed by the sense module  132  or the sense module  132  barely senses a magnetic field. 
     In one embodiment, assuming that the guiding object  110  is a virtual wall. When the cleaning robot  130  approaches the guiding object  110 , the control module  133  controls the traveling path of the cleaning robot  130  according to the sensed signal generated by the sense module  132 . In other words, the control module  133  controls the speed and the direction of the wheels  135  and  136 . 
     In another embodiment, assuming that the guiding object  110  is a docking station. When a power level of a storage module (not shown) of the cleaning robot  130  is less than a pre-determined level, the control module  133  controls the wheels  135  and  136  to move to the guiding object  110 . The storage module may be a rechargeable battery. The cleaning robot  130  can obtain an accurate position of the guiding object  110  according to the sensed signal generated by the sense module  132  and move to approach the guiding object  110 . 
     In some embodiments, the control module  133  obtains the state of the cleaning robot  130  according to the sensed signal generated by the sense module  132 . For example, when a duration in which a variation of the sensed signal generated by the sense module  132  is less than a pre-determined value exceeds to a pre-determined period, this represents that the cleaning robot  130  is at a fixed place. In one embodiment, the cleaning robot  130  may be locked at the fixed place. In this case, the control module  133  controls the direction of the wheels  135  and  136  to shake the cleaning robot  130  such that the cleaning robot  130  leaves the fixed place. 
     Furthermore, the control module  133  sends an audio effect or a light effect to display the operation state of the cleaning robot  130 . For example, when the cleaning robot  130  is at a fixed place, the control module  133  may control a buzzer (not shown) to buzz and send a warning signal or a warning light to notify users, such that the users may immediately determine that an abnormal event has occurred and eliminate the abnormal event. 
     To optimize the traveling path of the cleaning robot  130 , the cleaning robot  130  further comprises another sense module  137  in one embodiment. The sense module  137  generates another sensed signal according to an external environment of the cleaning robot  130 . The control module  133  adjusts the efficiency of at least one of the cleaning action and the moving action of the operation module  131  according to the other sensed signal generated by the sense module  137 . 
     For example, when the control module  133  obtains that the cleaning robot  130  is at a fixed place according to the sensed signal generated by the sense module  132 , the control module  133  adjusts the direction of the wheels  135  and  136  to shake the cleaning robot  130  and then adjusts the traveling path of the cleaning robot  130  according to the sensed signal generated by the sense module  137  such that the cleaning robot  130  leaves the fixed place. 
     The invention does not limit the circuit structure of the sense module  137 . In one embodiment, the sense module  137  comprises a photo sensor. The photo sensor generates a sensed signal according to a reflected light of the external environment. In another embodiment, the sense module  137  comprises an audio sensor, such as an ultrasonic sensor. The audio sensor generates a sensed signal according to a reflected audio wave of the external environment. 
       FIG. 2  is a schematic diagram of an exemplary embodiment of a control method of the invention. First, a magnet module is disposed in a guiding object to form a magnetic field (step S 210 ). In one embodiment, at least one NdFeB magnet is disposed in the guiding object, but the disclosure is not limited thereto. In other embodiments, other kinds of magnets may be disposed in the guiding object. 
     The magnetic field is sensed (step S 220 ). In one embodiment, step S 220  utilizes at least one of a compass sensor, a Hall sensor, a gyroscope and a g sensor to sense the magnetic field. 
     The efficiency of at least one of a cleaning action and a moving action performed by a cleaning robot is controlled according to the sensed signal (step S 230 ). In one embodiment, step  230  controls the speed of a cleaning brush  134 , or the suction or the air flow of a suction aperture  137  for controlling the cleaning action of the cleaning robot. Furthermore, step  230  controls the speed and the direction of wheels of the cleaning robot for controlling the moving action. 
       FIG. 3  is a schematic diagram of another exemplary embodiment of the control method of the invention.  FIG. 3  is similar to  FIG. 2 , except for the addition of steps S 340  and S 350 . Since steps S 310 ˜S 330  shown in  FIG. 3  and step S 210 ˜S 230  shown in  FIG. 2  have the same principles, descriptions of steps S 310 ˜S 330  are omitted for brevity. 
     In step S 340 , it is determined whether a duration, which a variation of the sensed signal generated by step S 320  is less than a pre-determined value in exceeds to a pre-determined period. When the duration, which the variation of the sensed signal generated by step S 320  is less than the pre-determined value in exceeds to the pre-determined period, this represents that the cleaning robot is at a fixed place. Thus, an external environment of the cleaning robot is sensed to generate a sensing result, and the efficiency of at least one of the cleaning action and the moving action is adjusted according to the sensing result (step S 350 ). 
     For example, when the cleaning robot is locked at a fixed place, the moving action is first adjusted to shake the cleaning robot. Then, another sense module is utilized to sense the external environment of the cleaning robot to generate another sensing result. The traveling path of the cleaning robot is adjusted according to the other sensing result such that the cleaning robot leaves the fixed place. Additionally, when the cleaning robot is at a fixed place, the cleaning action is stopped. After the cleaning robot leaves the fixed place, the cleaning action is performed. 
     In one embodiment, step S 350  utilizes a photo sensor, and the photo sensor senses a reflected light of the external environment of the cleaning robot. In another embodiment, step S 350  utilizes an audio sensor to sense a reflected audio wave of the external environment of the cleaning robot. 
     When the duration, which the variation of the sensed signal generated by step S 320  is less than the pre-determined value in does not exceed to the pre-determined period, this represents that the cleaning robot is not at a fixed place and is operating normally. Thus, step S 320  is performed to sense the variation of the sensed signal and then control at least one of the cleaning action and the moving action according to the sensing result. Furthermore, after executing step S 350 , step S 320  is performed to sense the magnet field. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.