Patent Publication Number: US-2018041683-A1

Title: High-dynamic-range sensing device and sensing method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a Divisional application of U.S. patent application Ser. No. 14/510,358, filed on 9 Oct. 2014, currently pending, which is based on Taiwan patent application Ser. No. 103121321, filed on 20 Jun. 2014, which are incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to a high-dynamic-range sensing device and the sensing method thereof, and particularly to a high-dynamic-range sensing device and the sensing method thereof that uses a control unit to rapidly abandon saturated sensing values from those given by a plurality of sensing units with different sensing ranges and switch among sensing units for achieving high-dynamic-range sensing. 
     BACKGROUND OF THE INVENTION 
     Animals always face a great deal of environmental information. Given the limited resources of energy and materials inside their bodies, it is not possible that they respond to all the stimuli from the environment. Instead, the information collected by sensory organs should be sifted before they can respond to important stimuli by using resources appropriately and thus extending their subsistence. 
     In the process when stimuli are transferred from the sensory nerves to the sensory centers, two types of sifting occur. One type of sifting occurs in the periphery nervous system for eliminating unnecessary environmental information at the sensory stage. The other occurs in the central nervous system for further sifting the information. For example, after odor molecules contact the cells in the antennal lobe of fruit flies, the signals will be transmitted to the glomeruli for noise filtering and signal strengthening. Then the signals will be transmitted to the mushroom bodies for signal analysis and judgment. Finally, the signals are transmitted to higher levels of the brain. Consequently, fruit flies can make dodging or approaching response to the source of odors. 
     In the nervous system of animals, signals can be sifted and responded rapidly using the feedback and inhibition among signal paths. The present inventor is inspired by the mechanism and provides a sensing device capable of selecting among multiple sensing units or the acquired multiple sensing values. By arranging the distribution of the sensing ranges of respective sensing units, the efficacy of high dynamic range can be attained. 
     SUMMARY 
     Accordingly, the present invention provides a high-dynamic-range sensing device and the sensing method thereof. The device comprises at least two sensing units having different sensing ranges and acquiring respective sensing values while sensing the target signal. In addition, a control unit is used for accepting or rejecting the sensing values or switching among the sensing units. In order to simply judgment, the control unit first rejects the sensing values of the sensing unit with saturated signals. Then it selects the most sensitive sensing unit among the ones without saturated signals. 
     SUMMARY 
     An objective of the present invention is to provide a high-dynamic-range sensing device, which uses a control unit to accept or reject the sensing values given by sensing units having different sensing ranges or switch among the sensing units for achieving high-dynamic-range sensing. 
     Another objective of the present invention is to provide a sensing method of high-dynamic-range sensing device, which uses a control unit to first reject the sensing values of the sensing units having saturated signals or interrupt their sensing for achieving accepting or rejecting sensing values rapidly or switching sensing units. 
     In order to achieve the objectives and efficacies described, the present invention discloses a high-dynamic-range sensing device, which comprises a first sensing unit, a second sensing unit, and a control unit. The first sensing unit has a first sensing upper limit, senses a target signal, and gives a first sensing value. The second sensing unit has a second sensing upper limit, which is greater than the first sensing upper limit, senses the target signal, and gives a second sensing value. The control unit is connected electrically to the first and second sensing units, receives the first and second sensing values, and rejects the first sensing value when the first sensing value is equal to the first sensing upper limit. 
     In addition, the present invention discloses a sensing method of high-dynamic-range sensing device applicable to the high-dynamic-range sensing device described above. First, the first and second sensing units sense the target signal and give the first and second sensing values. Next, the control unit receives the first and second sensing units and compares the first sensing value and the first sensing upper limit. If the first sensing value is equal to the first sensing upper limit, the control unit rejects the first sensing value; if the first sensing value is smaller than the first sensing upper limit, the control unit rejects the second sensing value. 
     Moreover, the present invention discloses another high-dynamic-range sensing device, which also comprises a first sensing unit, a second sensing unit, and a control unit. The difference is that the control unit further comprises a third sensing unit, which senses the target signal and gives a third sensing value. Then the control unit rejects the first sensing value or interrupts the sensing of the first sensing unit when the third sensing value is greater than or equal to the first sensing upper limit. 
     Besides, the present invention discloses another sensing method of high-dynamic-range sensing device application to the second high-dynamic-range sensing device described above. First, the first, second, and third sensing units sense the target signal and give the first, second, and third sensing values. Next, the control unit receives the first and second sensing values and compares the third sensing value and the first sensing upper limit. If the third sensing value is greater than or equal to the first sensing upper limit, the control unit rejects the first sensing value; if the third sensing value is smaller than the first sensing upper limit, the control unit rejects the second sensing value. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  shows a schematic diagram of component connection according to a preferred embodiment of the present invention; 
         FIG. 1B  shows a flowchart according to a preferred embodiment of the present invention; 
         FIG. 1C  shows a schematic diagram of device structure according to a preferred embodiment of the present invention; 
         FIG. 2A  shows a schematic diagram of component connection according to another preferred embodiment of the present invention; 
         FIG. 2B  shows a flowchart according to another preferred embodiment of the present invention; 
         FIG. 2C  shows a schematic diagram of device structure according to another preferred embodiment of the present invention; 
         FIG. 3A  shows a schematic diagram of component connection according to still another preferred embodiment of the present invention; 
         FIG. 3B  shows a flowchart according to still another preferred embodiment of the present invention; and 
         FIG. 3C  shows a schematic diagram of device structure according to still another preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In order to make the structure and characteristics as well as the effectiveness of the present invention to be further understood and recognized, the detailed description of the present invention is provided as follows along with embodiments and accompanying figures. 
     The present invention provides sensing device and the sensing method thereof characterized in that the control unit is used for comparing the sensing values of the sensing units and the sensing upper limits and rejecting rapidly the sensing values equal to the sensing upper limits for excluding the sensing units having saturated signals with respect to the target signal. Thereby, switching occurs among the sensing units having different sensing ranges. Alternatively, the most appropriate sensing value is selected from the sensing values. By arranging the sensing ranges of the sensing units, the effect of high-dynamic-range sensing can be achieved. 
     Please refer to  FIGS. 1A, 1B, and 1C , which show a schematic diagram of component connection, a flowchart, and a schematic diagram of device structure according to a preferred embodiment of the present invention. As shown in  FIG. 1A , the high-dynamic-range sensing device  1  according to the present invention is used for measuring a target signal  2 . The high-dynamic-range sensing device  1  at least comprises a control unit  10 , a first sensing unit  12 , and a second sensing unit  14 . The first and second sensing units  12 ,  14  are connected electrically with the control unit  10 , respectively. 
     The first and second sensing units  12 ,  14  sense the target signal  2  simultaneously and give a first sensing value and a second sensing value, respectively. The first and second sensing values are transmitted to the control unit  10 . 
     The upper limit of the first sensing unit  12  for sensing signal is a first sensing upper limit; the lower limit thereof is a first sensing lower limit. The range between the first sensing lower limit and the first sensing upper limit is called a first sensing range of the first sensing unit  12 . Besides, the upper limit of the second sensing unit  14  for sensing signal is a second sensing upper limit; the lower limit thereof is a second sensing lower limit. The range between the second sensing lower limit and the second sensing upper limit is called a second sensing range of the second sensing unit  14 . 
     The first sensing upper limit is smaller than the second sensing upper limit, which means that the first sensing unit  12  is easier to reach signal saturation than the second sensing unit  14 . When the real value of the target signal  2  is greater than or equal to the first sensing upper limit, the first sensing value is equal to the first sensing upper limit, the signal is saturated and the real value of the target signal  2  cannot be represented. At this time, if the real value of the target signal  2  is still smaller than the second sensing upper limit and within the second sensing range, the second sensing value can be used for representing the real value of the target signal  2 . 
     According to the present embodiment, the first sensing lower limit is smaller than the second sensing lower limit, which means that the first sensing unit  12  is more sensitive than the second sensing unit  14 . In addition, the second sensing lower limit is smaller than the first sensing upper limit. By arranging and linking the first and second sensing ranges, a wider range of the real value of the target signal  2  can be covered, and thus achieving high-dynamic-range sensing. 
     Accordingly, when the first sensing value is equal to the first sensing upper limit, the first sensing unit  12  has reached signal saturation. Then the control unit  10  rejects the first sensing value and accepts the second sensing value. On the contrary, when the first sensing value is smaller than the first sensing upper limit, the control unit  10  rejects the second sensing value and accepts the first sensing value. 
     As shown in  FIG. 1B , the sensing method of high-dynamic-range sensing device according to the present invention at least comprises the following steps:
     Step S 10 : The first sensing unit senses the target signal and gives the first sensing value, and the second sensing unit senses the target signal and gives the second sensing value simultaneously;   Step S 20 : The control unit receives the first sensing value and the second sensing value;   Step S 30 : The control unit compares the first sensing value and the first sensing upper limit;   Step S 40 : The control unit rejects the first sensing value; and   Step S 42 : The control unit rejects the second sensing value.   

     In the step S 10 , while sensing the target signal  2  using the high-dynamic-range sensing device  1  according to the present invention, the first and second sensing units  12 ,  14  sense the target signal  2  simultaneously and, as described above, give the first and second sensing values, respectively. In the step S 20 , the first and second sensing units  12 ,  14  transmit the first and second sensing values to the control unit  10 , respectively. The control unit  10 , as in the step S 30 , compares the first sensing value and the first sensing upper limit for accepting or rejecting the first and second sensing values. 
     As described above, when the first sensing value is equal to the first sensing upper limit, it means that the target signal  2  saturates the first sensing unit  12 . Then the step S 40  is performed, in which step the control unit  10  rejects the first sensing value and accepts the second sensing value. On the contrary, when the first sensing value is smaller than the first sensing upper limit, it means that the first sensing unit  12  is not saturated. Then the step S 42  is performed, in which the control unit  10  rejects the second sensing value and accepts the first sensing value. 
     By using the disposition of components and steps described above, the high-dynamic-range sensing device  1  according to the present invention can use the control unit  10  to select the one of the first and second sensing values given by the first and second sensing units  12 ,  14  with a better sensing effect. In addition, because the control unit  10  needs to compare the first sensing value and the first sensing upper limit only, the quantity of computation is few. Thereby, it takes a short time to decide whether to accept or reject the first and second sensing values. 
     As shown in  FIG. 1C , the high-dynamic-range sensing device  1  according to the present embodiment is applied to optical sensing. The control unit  10 , the first sensing unit  12 , and the second sensing unit  14  are arranged in a matrix form as shown in the figure. The control unit  10  is placed at the center; the first and second sensing units  12 ,  14  surround the control unit  10  alternately. In this way, the first and second sensing unit  12 ,  14  can both have excellent sensing efficacy on the target signal  2 . 
     Please refer again to  FIGS. 1A and 1B . The high-dynamic-range sensing device  1  according to the present invention can further comprises a processing unit  16 , which is connected electrically with the control unit  10  and receives the first or second sensing value not rejected by the control unit  10 . According to the sensing method of high-dynamic-range sensing device, the following steps can be further included after the steps S 40  and S 42 :
     Step S 50 : The processing unit receives the second sensing value; and   Step S 52 : The processing unit receives the first sensing value.   

     The step S 50  is performed after the step S 40 . After the control unit  10  rejects the first sensing value, it transmits the second sensing value to the processing unit  16 . The step S 52  is performed after the step S 42 . After the control unit  10  rejects the second sensing value, it transmits the first sensing value to the processing unit  16 . The processing unit  16  can further operate and use the first or second sensing values. 
     Please refer to  FIGS. 2A, 2B, and 2C , which show a schematic diagram of component connection, a flowchart, and a schematic diagram of device structure according to a second preferred embodiment of the present invention. As shown in  FIG. 2A , the main difference between the present embodiment and the first one is that the second sensing unit  14  according to the present embodiment is formed by the first sensing unit  12  and a signal filtering unit  120 . The signal filtering unit  120  is disposed between the first sensing unit  12  and the target signal  2  for filtering the target signal  2 . 
     The target signal  2  filtered by the signal filtering unit  120  will make the first sensing unit  12  contained in the second sensing unit  14  produce a lower second sensing value, which is equivalent to adjusting the originally lower first sensing upper limit and first sensing lower limit of the first sensing unit  12  to the higher second sensing upper limit and second sensing lower limit by disposing the signal filtering unit  120 . 
     As shown in  FIG. 2B , in the step S 30 , the control unit  10  still judges the acceptance and rejection of the first and second sensing values by comparing the first sensing value and the first sensing upper limit. Because the second sensing value is given by sensing, instead of the real value, the target signal  2  filtered by the signal filtering unit  120 , according to the present embodiment, the following step is further included after the step S 50 :
     Step S 60 : The processing unit recovers the first sensing value.   

     When the signal filtering unit  120  filters the target signal  2 , the target signal  2  can be lowered by a ratio. In the step S 60 , the processing unit  16  recovers the second sensing value according to the ratio. For example, the signal filtering unit  120  can filter the target signal  2  by 20%. Then the processing unit  16  should recover the second sensing value by 125% for giving the real value of the target signal  2 . 
     By using the disposition of components and steps described above, according to the high-dynamic-range sensing device  1  of the present invention, the first sensing unit  12  can be used as the second sensing unit  14  by disposing the signal filtering unit  120 . When the second sensing unit  14  causes the first sensing unit  12  to saturate, the unsaturated second sensing unit  14  can be used for giving the second sensing value. Then the second sensing value is recovered to the real value of the target signal  2 . 
     As shown in  FIG. 2C , the high-dynamic-range sensing device  1  according to the present embodiment can also be applied to optical sensing. The signal filtering units  120  are arranged alternately, so that the first and second sensing unit  12 ,  14  are distributed interlacedly like a checkerboard. This arrangement enables the first and second sensing units  12 ,  14  to have excellent sensing effects on the target signal  2 . Besides, the first and second sensing values given by the first and second units  12 ,  14  are transmitted to the control unit  10 . 
     Please refer to  FIGS. 3A, 3B, and 3C , which show a schematic diagram of component connection, a flowchart, and a schematic diagram of device structure according to a third preferred embodiment of the present invention. As shown in  FIG. 3A , the main difference between the present embodiment and the first one is that the control unit  10  according to the present embodiment further comprises a third sensing unit  100 . Likewise, the third sensing unit  100  can sense the target signal  2  and give a third sensing value. The control unit  10  according to the present embodiment determines the acceptance or rejection of the first and second sensing values or switches between the first and second sensing units  12 ,  14  according to the third sensing value. 
     The upper limit of the third sensing unit  100  for sensing signal is a third sensing upper limit; the lower limit thereof is a third sensing lower limit. The range between the third sensing lower limit and the third sensing upper limit is called a third sensing range of the third sensing unit  100 . The third sensing range should cover the first sensing upper limit, so that the third sensing value can be used for judging if the first sensing unit  12  has saturated. 
     As shown in  FIG. 3B , according to the disposition of the third sensing unit  100 , the step S 10  is adjusted to a step S 12 ; the step S 30  is adjusted to a step S 32 ; the step S 40  is adjusted to a step S 44 ; and the step S 42  is adjusted to a step S 46 .
     Step S 12 : The first sensing unit senses the target signal and gives a first sensing value; the second sensing unit senses the target signal and gives a second sensing value; and the third sensing unit senses the target signal and gives a third sensing value simultaneously;   Step S 32 : The control unit compares the third sensing value and the first sensing upper limit;   Step S 44 : The control unit rejects the first sensing value or interrupts the sensing of the first sensing unit; and   Step S 46 : The control unit rejects the second sensing value or interrupts the sensing of the second sensing unit.   

     In the step S 12 , the first, second, and third sensing units  12 ,  14 ,  100  sense the target signal  2  simultaneously and give the first, second, and third sensing values, respectively. 
     As described above, the control unit  10  according to the present embodiment determines the acceptance or rejection of the first and second sensing values or switches between the first and second sensing units  12 ,  14  according to the third sensing value. Thereby, in the step S 32 , the control unit  10  compares the third sensing value and the first sensing upper limit for judging whether the first sensing value or the second sensing value should be rejected, or whether the sensing of the first sensing unit  12  or the second sensing unit  14  should be interrupted. 
     When the third sensing value is greater than or equal to the first sensing upper limit, it means that the target signal  2  saturates the first sensing unit  12 . At this time, the step S 44  is performed, in which the control unit  10  rejects the first sensing value and accepts the second sensing value, or interrupts the sensing of the first sensing unit  12 . On the contrary, when the third sensing value is smaller than the first sensing upper limit, it means that the first sensing unit  12  has not saturated yet. Then the step S 46  is performed, in which the control unit  10  rejects the second sensing value and accepts the first sensing value, or interrupts the sensing of the second sensing unit  12 . Because the control unit  10  adopts the third sensing value, instead of the first sensing value given by the first sensing unit  12 , as the basis for judgment, interruption of the first sensing unit  12  will not influence the normal operation of the high-dynamic-range sensing device  1  according to the present embodiment. 
     By using the disposition of components and steps described above, the high-dynamic-range sensing device  1  according to the present invention acquires the third sensing value given by the third sensing unit  100 . The third sensing value replaces the first sensing value and is used as the basis for judgment by the control unit  10 . Consequently, in addition to accepting or rejecting the first and second sensing values, the sensing of the first or second sensing unit  12 ,  14  can be further interrupted. Hence, the control unit  10  switches between the first and second sensing units  12 ,  14 . 
     As shown in  FIG. 2C , the high-dynamic-range sensing device  1  according to the present embodiment can also be applied to sensing acoustic waves. The third sensing unit  100 , which is capable of sensing the volume of sound, in the control unit  10  can sense the target signal  2 . Switches are performed between two microphones having different sound sensing ranges, which are just the first and second sensing units  12 ,  14 . Thereby, when the volume is smaller, the first sensing unit  12  having a lower first sensing lower limit (more sensitive) can be adopted. When the volume is larger, the second sensing unit  14  having a higher second sensing upper limit can be used instead for avoiding noise interference such as popping due to excessive volume of sound. 
     To sum up, the present invention provides a high-dynamic-range sensing device and the sensing method thereof. In the sensing method, the sensing units give sensing values, and then the control unit compares the sensing values and the upper sensing limit of the sensing units, respectively. When a sensing value is equal to the upper sensing limit, the control unit rejects the sensing value or interrupts the sensing of the sensing unit thereof. Thereby, the sensing device quickly excludes the sensing units that obtain saturated signals and their sensing values and thus switches between the alternative sensing units with different sensing ranges or picks up the optimum one of the sensing values. 
     Accordingly, the present invention conforms to the legal requirements owing to its novelty, nonobviousness, and utility. However, the foregoing description is only embodiments of the present invention, not used to limit the scope and range of the present invention. Those equivalent changes or modifications made according to the shape, structure, feature, or spirit described in the claims of the present invention are included in the appended claims of the present invention.