Abstract:
An active three-dimensional positioning device and a control system for floor-cleaning robot are provided in the present invention. The active three dimension positioning device includes a radio frequency (RF) receiver array, a radio frequency emitter and a control circuit. The RF receiver array includes a plurality of RF receivers for receiving a RF pulse. The RF emitter is used for emitting a RF pulse. The control circuit is coupled to the RF receivers. The control circuit transmits a transmission command to the RF emitter, after the RF emitter receives the enable RF signal, and the RF emitter emits the RF pulse. The control circuit calculates the position between the RF receiver array and the RF emitter according to the positions of the RF receivers and the time when each of the RF receivers receives the RF pulse.

Description:
[0001]    This application claims priority of No. 102128038 filed in Taiwan R.O.C. on Aug. 6, 2013 under 35 USC 119, the entire content of which is hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to a technology of coordinate detection, and more particularly to an active three-dimensional positioning device and a control system for floor-cleaning robot thereof. 
         [0004]    2. Related Art 
         [0005]    With the progress of the technology, the electronic technology has been progressed from the earliest vacuum tube and transistor to the integrated circuit chip, which has the quite wide applications. Thus, the electronic products have gradually become the indispensable essentials in the life of the modern human beings. At present, because of the advance of the human factors engineering, the user interface of a digital electronic product, such as cell-phone, tablet computer, becomes more and more humanized. However, the coordinate information of the mobile device still depends on the satellite positioning system. However, the satellite positioning system can only determines the 2D coordinate of the device. The height information cannot be obtained from the satellite positioning system. 
         [0006]    In addition, the gesture operation of the mobile device generally adopted to detect the acceleration information obtained from the gyroscope or G-sensor/accelerometer. 
       SUMMARY OF THE INVENTION 
       [0007]    In view of the above-identified problems, it is therefore an object of the invention to provide an active three-dimensional positioning device. The position of the RF emitter can be obtained according to the time when a plurality of RF receivers respectively receive the RF pulse. 
         [0008]    In the embodiment of the present invention, the velocity and the acceleration can be also obtained according to the abovementioned position. 
         [0009]    Another object of the invention is to provide a control system for floor-clean robot. The system can calculate the position of the floor-clean robot according to the time when a plurality of RF receivers respectively receive the RF pulse. In addition, the system can record the moving path of the floor-clean robot. Therefore, the floor-clean robot is controlled to come back to the charging interface to charge the battery when the power of the floor-clean robot is low. 
         [0010]    To achieve the above-identified object, the invention provides an active three-dimensional positioning device. The active three-dimensional positioning device includes a radio frequency (RF) receiver array, an RF emitter and a control circuit. The RF receiver array includes a plurality of RF receivers. Each RF receiver is used for receiving a RF pulse. The RF emitter is for emitting the RF pulse. The control circuit is coupled to the RF receivers. When the control circuit outputs a transmission command to the RF emitter and the RF emitter receives the transmission command, the RF emitter emits the RF pulse. According to receiving time when the RF receivers respectively receive the RF pulse and positions of the RF receivers, the control circuit calculates a relative position between the RF receiver array and the RF emitter. 
         [0011]    According to the active three-dimensional positioning device in a preferred embodiment of the present invention, the control circuit is further used for performing a differential calculation to calculate the velocity between the RF receiver array and the RF emitter. In another preferred embodiment, the control circuit is further used for performing a second order differential calculation to calculate the acceleration between the RF receiver array and the RF emitter. Furthermore, in a preferred embodiment, the number of the RF receivers is at least four. Moreover, in a preferred embodiment, the control circuit includes an RF base station and a calculating circuit. The RF base station is used for emitting a transmission command. The calculating circuit is used for calculating the relative position between the RF emitter and the RF receiver array according to the positions of the RF receivers and the time when the RF receivers respectively receive the RF pulse. In a preferred embodiment, the second RF emitter is also provided. The abovementioned control method is adopted to obtain the position information of the second RF emitter. 
         [0012]    The spirit of the present invention is to utilize an RF emitter to emit an RF pulse, and a plurality of RF receivers to receive the RF pulse. According to the RF receivers respectively receiving the RF pulse time difference, the relative positions between the RF emitter and the respective RF receivers can be determined. Thus, the position of the user with the RF emitter can be determined. 
         [0013]    Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention. 
           [0015]      FIG. 1  illustrates a diagram depicting an active three-dimensional positioning device according to a preferred embodiment of the present invention. 
           [0016]      FIG. 2  illustrates a diagram depicting the configuration of RF receiver array  101  according to a preferred embodiment of the present invention. 
           [0017]      FIG. 3  illustrates a diagram depicting a control system for floor-cleaning robot having the active three-dimensional positioning device according to a preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements. 
         [0019]      FIG. 1  illustrates a diagram depicting an active three-dimensional positioning device according to a preferred embodiment of the present invention. Referring to  FIG. 1 , the active three-dimensional positioning device includes an RF receiver array  101 , RF emitters  102 ,  103  and a control circuit  104 . The RF receiver array  101  includes four RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4 . The control circuit  104  includes an RF base station  104 - 1  and a calculation circuit  104 - 2 . 
         [0020]    In the present embodiment, the active three-dimensional positioning device is used for detecting the position, velocity and acceleration of the RF emitter  102 . In the beginning, the RF base station  104 - 1  would emits a transmission command COMMAND-1 corresponding to the RF emitter  102 . The RF emitters  102  and  103  would receive the transmission command COMMAND-1. However, only the RF emitter  102  would be enabled to emit the RF pulse RFP1. Since the RF pulse RFP1 is omni-directional, the four RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  of the RF receiver array  101  would receive the RF pulse RFP1. 
         [0021]    Since the distances between the RF emitter  102  and the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  differ from each other, the received time, at which the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  respectively receive the RF pulse RFP1, may slightly differ from each other. At this time, the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  would transmit the time receiving the RF pulse RFP1 to the control circuit  104 . The calculating circuit  104 - 2  of the control circuit  104  would calculate the periods from the time when the transmission command COMMAND-1 is emitted to the time when the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  respectively receive the RF pulse RFP1 to obtain the distances between the RF emitter  102  and the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4 . Thus, the position of the RF emitter  102  can be obtained by the calculating circuit  104 - 2 . In the present embodiment, the transmission command COMMAND-1 can be implemented by RF signal, IR signal, microwave or the other transmission interface. 
         [0022]    In order to conveniently describe the spirit of the present invention, the exemplary configuration of the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  is provided.  FIG. 2  illustrates a diagram depicting the configuration of RF receiver array  101  according to a preferred embodiment of the present invention. Referring to  FIG. 2 , the RF receivers  101 - 1 ,  101 - 2  and  101 - 3  is disposed on the same plane. The RF receiver  101 - 4  is disposed on the upper side of the plane. According to the disposed positions of the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4 , the configuration of the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  are equivalent to the elements distributed in X, Y, Z planes such as the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  can be used for detecting the position of the RF emitter in three-dimensional space. Although, the number of the RF receivers in the present embodiment is four, people having ordinary skills in the art should know that the number of the RF receivers would be modified according to the requirement of the product or the application. In addition, the set-up position of the RF receivers can be modified according to design. Thus, the present invention does not limited thereto. 
         [0023]    Further, since the transmission speed of the RF pulse are extremely fast, the distance determination by the control circuit  104  may fail when the distances between the RF emitter  102  and the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  are too short. Therefore, the time intervals, from the time when the RF emitter  102  emits the RF pulse to the time when the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  respective receive the RF pulse, are the order of time in nanosecond, determination error inevitably occurs. At this time, the control circuit  104  would control the RF base station  104 - 1  to emit the transmission command COMMAND-1 once again to the RF emitter  102 , such that the RF emitter  102  would once again emit the RF pulse RFP1. Thus, the control circuit  104  can re-determine the distances between the RF emitter  102  and the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4 . Moreover, Diffraction, reflection or refraction phenomenon is more likely to occur when the RF signal encounters an obstacle, the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  may repeatedly receive the reflected or refracted RF pulse. Thus, in the present embodiment, the control circuit  104  uses the time when the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  first receive the RF pulse RFP1 to calculate the distances, and then the following received RF pulse would be served as a noise. In addition, people having ordinary skills in the art should know that the control circuit  104  also can adopt the time when RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  receive the most powerful received RF pulse RFP1 to calculate the distances. Thus, the present invention is not limited thereto. 
         [0024]    In the preferred embodiment, in order to perform the detection accurately, the control circuit  104  can repeatedly output the transmission command COMMAND-1 to request the RF emitter  102  to emit the RF pulses RFP1 repeatedly, and the control circuit  104  detects and records the time when the RF pulse RFP1 is received after each transmission command COMMAND-1 is sent. Afterward, statistical calculation is performed and the accurate position information is obtained to reduce the error. 
         [0025]    According to the abovementioned method for detecting the position, the control circuit  104  can obtain the moving path and its corresponding time point of the RF emitter  102  according to the plurality calculating result. Afterward, the differential calculation is adopted to obtain the velocity and acceleration of the RF emitter  102 . 
         [0026]    Similarly, to detect the position, velocity, acceleration of the RF emitter  103 , the RF base station  104 - 1  would emits a transmission command COMMAND-2 corresponding to the RF emitter  103 . The RF emitters  102  and  103  would receive the transmission command COMMAND-2, but only the RF emitter would be enabled to emit the RF pulse RFP2. Since the RF pulse RFP2 is omni-directional, the four RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  of the RF receiver array  101  would receive the RF pulse RFP2. 
         [0027]    Since the distances between the RF emitter  103  and the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  differ from each other, the received time, at which the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  respectively receive the RF pulse RFP2, may slightly differ from each other. At this time, the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  would transmit the time receiving the RF pulse RFP2 to the control circuit  104 . The calculating circuit  104 - 2  of the control circuit  104  would calculate the periods from the time when the transmission command COMMAND-2 is emitted to the time when the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  respectively receive the RF pulse RFP2 to obtain the distances between the RF emitter  103  and the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4 . Thus, the position of the RF emitter  103  can be obtained by the calculating circuit  104 - 2 . Since the method for determining the position, velocity and acceleration of the RF emitter  103  is the same as the method for determining the position, velocity and acceleration of the RF emitter  102 , the detail description thereof is omitted. 
         [0028]    Further, the abovementioned application can be used in floor-clean robot. As shown in  FIG. 3 ,  FIG. 3  illustrates a diagram depicting a control system for floor-cleaning robot having the active three-dimensional positioning device according to a preferred embodiment of the present invention. Referring to  FIG. 3 , in this embodiment, the control system for floor-cleaning robot includes a RF receiver array  101 , a floor-cleaning robot with a RF emitter  301 , a charging interface  302  and a control circuit  104 . The RF receiver array  101  also includes four RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4 . The control circuit  104  includes an RF base station  104 - 1  and a calculating circuit  104 - 2 . 
         [0029]    First, in the beginning of the detection, the RF base station  104 - 1  would emits a transmission command COMMAND-1 corresponding to the RF emitter of the floor-cleaning robot  301 . The RF emitter of the floor-cleaning robot  301  would receive the transmission command COMMAND-1 and then emit the RF pulse RFP1. Since the RF pulse RFP1 is omni-directional, the four RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  of the RF receiver array  101  would receive the RF pulse RFP1. 
         [0030]    Since the distances between the RF emitter  102  and the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  differ from each other, the received time, at which the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  respectively receive the RF pulse RFP1, may slightly differ from each other. At this time, the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  would transmit the time points of receiving the RF pulse RFP1 to the control circuit  104 . The calculating circuit  104 - 2  of the control circuit  104  would calculate the periods from the time when the transmission command COMMAND-1 is emitted to the time when the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4  respectively receive the RF pulse RFP1 to obtain the distances between the floor-cleaning robot  301  and the RF receivers  101 - 1 ,  101 - 2 ,  101 - 3  and  101 - 4 . Thus, the relative position between the floor-cleaning robot  301  and the RF receiver array  101  and the corresponding coordinate of the floor-cleaning robot  301  can be determined. Further, if the detection time is sufficient, the moving path can be also obtained. The control system can illustrate the plane view of the floor by this technique. When the power of the floor-cleaning robot  301  is low, the system can determine the preferred path to go back to the charging interface according to the moving path thereof. 
         [0031]    Similarly, in the abovementioned embodiment, only one floor-cleaning robot  301  is controlled. People having ordinary skills in the art should know that it is similar to control two or more floor-cleaning robots according to the abovementioned embodiment. Thus, the present invention is not limited thereto. Further, beside the floor-cleaning robot, the present invention also can be applied to position model aircraft, amusement equipment, smart phone, and so on. Thus, the present invention is not limited thereto. 
         [0032]    In summary, the spirit of the present invention is to utilize an RF emitter to emit an RF pulse, and a plurality of RF receivers to receive the RF pulse. According to the time difference when the RF receivers respective receive the RF pulse to determine the relative positions between the RF emitter and the respective RF receivers. Thus, the position of the user with the RF emitter can be determined. 
         [0033]    While the invention has been described by way of examples and in terms of preferred embodiments, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications.