Abstract:
The present disclosure relates to gesture based control of an electronic device and in particular to a method and system for gaining control over the electronic device. 
     For publication: FIG.  6

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates to gesture based control of an electronic device and in particular to a method and system for gaining control over the electronic device. 
       TECHNICAL BACKGROUND 
       [0002]    Gesture controlled systems are getting more and more common in today&#39;s society. For example, there are several companies developing software facilitating gesture control of Smartphones and other wearable electronics such as tablets. Such software often uses images captured by a camera for controlling the electronic devices. These implementations are for example advantageous for controlling a Smartphone when sitting in a car, e.g. increasing the volume of music played via the Smartphone. A camera has a limited range for capturing images, and these systems are often designed for applications where one person can and wants to control the electronic device. 
         [0003]    One such system is described in US 2014/032573 (OBLONG INDUSTRIES INC.). The document relates to a system which identifies gesture of a user using only gesture data received by a sensor. A computer application translates the gesture to a gesture signal, and controls a connected display device in response to the gesture signal. 
         [0004]    However, further development of systems for controlling devices via gestures is needed in order to broaden the range of application where such gesture based systems may be used. 
       SUMMARY 
       [0005]    In view of the above, an objective of the invention is to solve or at least reduce one or several of the drawbacks discussed above. Generally, the above objective is achieved by the attached independent patent claims. 
         [0006]    According to a first aspect, the present invention is realized by a method for controlling an electronic device being connected to a control unit. The control unit is connected to at least one sensor. The electronic device is configured to be controlled, via the control unit, by gestures of an object being sensed at a distance from the at least one sensor. The method comprising the steps of: 
         [0007]    sensing, by the at least one sensor, a first gesture input from a first object, 
         [0008]    checking, by the control unit, whether the first gesture input corresponds to a first predetermined gesture of gaining control of the electronic device. 
         [0009]    If the first gesture input corresponds to the first predetermined gesture, the method further comprising approving, by the control unit, the first object to gain control over the electronic device. 
         [0010]    In other words, if the control unit determines that the first gesture input corresponds to the first predetermined gesture, the control unit will approve the first object to gain control over the electronic device. 
         [0011]    Each of the at least one sensor could be either an active sensor from which some kind of signals are transmitted which then is reflected, refracted or scattered and then measured when received by the sensor again, and/or a passive sensor which just receives signals. If a plurality of sensors is used, the plurality can thus comprise different type of sensors. 
         [0012]    By the term “object” should, in the context of present specification, be understood any type of suitable object for performing gestures, e.g. one hand, two hands, an arm, two arms, a remote control etc. 
         [0013]    By the term “electronic device” should, in the context of present specification, be understood any type of electronic device, e.g. a stereo, a television, an input means of a computer (a virtual keyboard), a robot etc. 
         [0014]    The present invention is based on the realization that by having a predetermined gesture that has to be performed by a user in order to gain control over the electronic device, the gesture based control system can better handle when the at least one sensor is sensing gestures from separate objects (e.g. hands belonging to different persons) at the same time. For example, if the at least one sensor is connected to a gesture based control system for controlling a stereo, and several different persons are trying to change the volume of the played music, sensed gestures from persons which have not performed the predetermined gesture for gaining control over the stereo can be neglected by the control unit. 
         [0015]    According to embodiments, the method further comprises the steps of: sensing, by the at least one sensor, a second gesture input from a second object different from the first object, and ignoring, by the control unit, the second gesture input from the second object as long as the first object is in control over the electronic device. 
         [0016]    Consequently, if a first object (e.g. the hands of a first person) has gained control over the electronic device, and a second object (e.g. the hands of a second person) tries to gain control over or otherwise control the electronic device, this is ignored by the control unit. This may be advantageous for many reasons, for example if the gesture based control system is connected to a large manufacturing robot, different persons controlling such machine at the same time would end in disaster. 
         [0017]    According to embodiments, wherein the first object is in control over the electronic device, the method further comprising the steps of: sensing, by the at least one sensor, a third gesture input from the first object, checking, by the control unit, whether the third gesture input corresponds to a second predetermined gesture of releasing control of the electronic device, and if the third gesture input corresponds to the second predetermined gesture, releasing, by the controlling unit, the first object from the control over the electronic device. 
         [0018]    Having a predefined gesture for releasing control over the electronic device results in a more flexible gesture based control system since an object can be released from control in a controlled manner. 
         [0019]    According to embodiments, wherein the first object is not in control over the electronic device, the method further comprises the steps of: sensing, by the at least one sensor, a fourth gesture input from a second object, checking, by the control unit, whether the fourth gesture input corresponds to the first predetermined gesture of gaining control of the electronic device, and if the fourth gesture input corresponds to the first predetermined gesture, approving, by the control unit, the second object to gain control over the electronic device. 
         [0020]    Consequently, when the first object has been released from control over the electronic device, a new object (e.g. the second object) can gain control over the same. This is advantageous since a more controlled transfer of control from one user to another over the electronic device may be achieved. 
         [0021]    According to some embodiments, after step of approving, by the control unit, the first object to gain control over the electronic device, the method further comprises the steps of: determining, by the control unit, a position in 3d space for the first gesture input, setting, by the control unit, the position in 3d space as a origin in a 3d coordinate system, and using, by the control unit, the 3d coordinate system and further gesture inputs from the first object for controlling the electronic device. 
         [0022]    In gesture based control system, it may be advantageous to define a coordinate system for the gestures. For example, by defining such coordinate system, gesture inputs, relating to the same object, from different sensors may be compiled in into one gesture input since the coordinate system may facilitate tracking of an object between the different sensors. This is advantageous when interpreting the gesture input, since more data will be available for the gesture input. 
         [0023]    By defining this coordinate system in conjunction with the gesture for gaining control over the electronic device, the process of setting the coordinate system may be simplified. Consequently, no specific gesture needs to be performed in order to set the coordinate system. 
         [0024]    According to some embodiments, if the first object is released from the control over the electronic device, and a second object is gaining the control by performing the predefined gesture for gaining control, this gesture will set a new coordinate system. 
         [0025]    According to some embodiments, the first object comprises two objects. In this case, first predetermined gesture and the second predetermined gesture, if applicable, may correspond to a gesture input of both said two objects. 
         [0026]    By requiring a gesture from two objects, e.g. from both hands of a user, the risk of gaining and releasing control over the electronic device by mistake may be reduced. 
         [0027]    According to some embodiments, the first predetermined gesture comprises a predetermined gesture corresponding to a gesture input from a single object and a predetermined gesture corresponding to a gesture input from two objects, and wherein the second predetermined gesture, if applicable, comprises a predetermined gesture to be performed by a single object and a predetermined gesture to be performed by two objects. 
         [0028]    Consequently, an increased flexibility may be achieved since gestures by a single object as well as gestures by two objects can be used for gaining control over the electronic device and, if applicable, for being released from the control. For example, there are fields of application where a user may only have one hand free for controlling the electronic device, e.g. if a doctor is performing surgery and is holding an instrument one of his/hers hands. 
         [0029]    In a second aspect, the present invention provides a computer program product comprising a computer-readable storage medium with instructions adapted to carry out the method according to the first aspect when executed by a device having processing capability. 
         [0030]    In a third aspect, the present invention provides a system for controlling an electronic device, the system comprising: a control unit, at least one sensor configure to sense gesture inputs from objects at a distance from the at least one sensor, a memory configured to store a first predetermined gesture of gaining control of the electronic device, the electronic device being configured to be controlled, via the controller unit, by gesture inputs sensed by the at least one sensor, wherein, in response to a first gesture input, from a first object, being sensed by the at least one sensor, the control unit is configured to check whether the first gesture input corresponds to the first predetermined gesture stored in the memory, and, if the first gesture input corresponds to the first predetermined gesture, to approve the first object to gain control over the electronic device. 
         [0031]    According to some embodiments, wherein in response to a second gesture input, from a second object different from the first object, being sensed by the at least one sensor, the control unit is configured to ignore the second gesture input from the second object as long as the first object is in control over the electronic device. 
         [0032]    According to some embodiments, wherein the first object is in control over the electronic device, wherein the memory is further configured to store a second predetermined gesture of releasing control of the electronic device, wherein, in response to a second gesture input, from the first object, being sensed by the sensor, the control unit is configured to check whether the third gesture input corresponds to a second predetermined gesture, and if the third gesture input corresponds to the second predetermined gesture, to release the first object from the control over the electronic device. 
         [0033]    According to some embodiments, wherein the first object is not in control over the electronic device, wherein, in response to a fourth gesture input, from the second object, being sensed by the sensor, the control unit is configured to check whether the fourth gesture input corresponds to the first predetermined gesture of gaining control of the electronic device, and if the fourth gesture input corresponds to the first predetermined gesture, to approve the second object to gain control over the electronic device. 
         [0034]    According to some embodiments, wherein when the control unit has approved the first object to gain control over the electronic device, the control unit is configured to: determine a position in 3d space for the first gesture input, set the position in 3d space as an origin in a 3d coordinate system, and use the 3d coordinate system and further gesture inputs from the first object for controlling the electronic device. 
         [0035]    According to some embodiments, wherein the first object comprises two objects, and wherein the first predetermined gesture and the second predetermined gesture, if applicable, corresponds to a gesture input of both of said two objects. 
         [0036]    According to some embodiments, wherein the first predetermined gesture comprises a predetermined gesture corresponding to a gesture input from a single object and a predetermined gesture corresponding to a gesture input from two objects, and wherein the second predetermined gesture, if applicable, comprises a predetermined gesture to be performed by a single object and a predetermined gesture to be performed by two objects. 
         [0037]    The second and third aspect may generally have the same features and advantages as the first aspect. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0038]    The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of embodiments of the present invention, with reference to the appended drawings, where the same reference numerals will be used for similar elements, wherein: 
           [0039]      FIG. 1  describes by way of example a system for controlling an electronic device by gestures, 
           [0040]      FIGS. 2 a - b    describe by way of example a two hand gesture for gaining control over the electronic device, 
           [0041]      FIG. 3  describes by way of example a two hand gesture for releasing the control over the electronic device, 
           [0042]      FIGS. 4 a - b    describe by way of example a one hand gesture for gaining control over the electronic device, 
           [0043]      FIG. 5  describes by way of example a one hand gesture for releasing the control over the electronic device, 
           [0044]      FIG. 6  describes by way of example a method for controlling an electronic device. 
       
    
    
     DETAILED DESCRIPTION 
       [0045]      FIG. 1  describes a system  100  for controlling an electronic device  114 . The system in  FIG. 1  comprises three sensors  102 ,  104 ,  106  but any number of sensors may be employed. A sensor  102 ,  104 ,  106  may be an active sensor, e.g. an IR-sensor, an ultra sound sensor or a laser sensor, or a passive sensor, e.g. a camera. According to some embodiments, when a plurality of sensors is employed, the plurality comprises sensor of different kind, e.g. one camera and two IR-sensors. The sensors  102 ,  104 ,  106  are configured to sense gesture inputs from objects  116 ,  120  at a distance from the sensors  102 ,  104 , 106 . As described above, the objects  116 ,  120  each may comprise one or several sub-objects, for example one or two hands of a person controlling the electronic device with gestures by the hand(s). The system  100  further comprises a driver  108  to translate the signals from the sensors  102 ,  104 ,  106  to gesture input signals having a format which a connected control unit  112  is adapted to recognize. This setup is advantageous in that different type of sensors, e.g. from different manufacturers can be used, as long as the driver  108  comprises software that can handle the specific type of sensor. The control unit  112  is further connected to a memory  110  which can store predetermined gestures to be used in order to control the electronic device  114 . The control unit  112  is thus configured to compare gesture inputs received from the driver  108  with the predetermined gestures stored in the memory  110  in order to control the electronic device  114 . In other words, the electronic device  114  is configured to be controlled, via the controller unit  112 , by gesture inputs sensed by the at least one sensor  102 ,  104 ,  106 . 
         [0046]    For example, if the electronic device  114  is a tablet computer having a virtual keyboard to be controlled, the predetermined gestures may relate to inputting the letters and numbers of the keyboard. Specifically, the memory  110  is configured to store a first predetermined gesture of gaining control of the electronic device. Such a gesture may reduce the risk of someone or something controlling the electronic device by mistake, e.g. a person passing by within a sensing range of the sensors  102 ,  104 ,  106  and performing one of the gestures stored in memory  110 . By defining a specific predetermined gesture, i.e. the first predetermined gesture, for gaining control of the electronic device, the risk of such inadvertently control of the electronic device is reduced. 
         [0047]    Consequently, in response to a first gesture input, from the first object  116 , being sensed by the at least one sensor, the control unit  112  is configured to check whether the first gesture input corresponds to the first predetermined gesture stored in the memory  110 . If the gesture input corresponds, i.e. matches, with the first predetermined gesture, the control unit  112  is configured to approve the first object  116  to gain control over the electronic device. 
         [0048]    It should be noted that the driver  108 , control unit  112  and memory  110  may be implemented and located within the electronic device  114  to be controlled. The sensor(s)  102 ,  104 ,  106  may also be located in the electronic device, e.g. a camera in a laptop. However, it may be advantageous if at least the sensors  102 ,  104 ,  106  are located away from the electronic device  114  to be controlled, which increased the flexibility for controlling the electronic device since the gestures do not need to be sensed in vicinity of the electronic device. Furthermore, the driver  108 , control unit  112  and memory  110  may be separate devices or implemented in a single device  107 , e.g. a computer  107  that can be connected to sensors and to the electronic device  114  to be controlled. The connection between the sensors  102 ,  104 ,  106  and such computer  107  or separate driver device  108  may be a wireless (e.g. Wi-Fi) or a wired connection. The same is valid for the connection between the control unit  112  and the electronic device  114  to be controlled. The driver  108  and the control unit  112  may be implemented in software and executed by one or more processors. The one or more processors may include a central processing unit (CPU) and/or a graphical processing unit (GPU). The memory  110  may include, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. 
         [0049]    According to some embodiments, when gestures are sensed by the sensors,  102 ,  104 ,  106  the control unit  112  is configured to first check if the control have been appointed another object, e.g. the first object  116 . If this is true, the control unit  112  is configured to ignore the gesture input from another object, e.g. from the second object  120 , as long as the first object  116  is in control over the electronic device  114 . According to some embodiments, the sensor  102 ,  104 ,  106  can keep track of objects and their respective gestures. According to other embodiments, this functionality is implemented in the control unit  112 . As described above, the control unit  112  may use a coordinate system along with the gesture inputs from the sensor(s) for keeping track of different objects which are sensed by the sensor(s). 
         [0050]    Among the predetermined gestures stored in the memory  110 , there may exist a second predetermined gesture of releasing control of the electronic device  114 . In this case, the control unit  112  is configured to check whether a gesture input from an object, e.g. the first object  116 , in control of the electronic device  114 , corresponds to the second predetermined gesture of releasing control of the electronic device. It the gesture input corresponds to the second predetermined gesture, the control unit  112  is configured to release the first object  116  from the control over the electronic device  114 . 
         [0051]    According to some embodiments, the sensors  102 ,  104 ,  106  or the driver  108  or the control unit  112  are adapted to recognize when an object in control of the electronic device  114  is no longer within a control area. The control area may be e.g. the sensing area of the sensors  102 ,  104 ,  106 , or an area a bit smaller than the sensing area. The control area can be configured and saved into the memory  110 . Consequently, the control unit may read the control area from the memory and e.g. disregard gesture inputs received from outside the control area. If the object in control is exiting the control area, the control unit  112  may be adapted to release the object from the control. According to some embodiments, this is the only way of releasing an object from the control, i.e. a predetermined gesture for releasing the control does not exist. 
         [0052]    If the control unit  112  has released the first object  116  from the control, the control unit  112  is configured to check whether a gesture input from the second object  120  corresponds to the first predetermined gesture of gaining control of the electronic device  114 . If the gesture input matches the predetermined gesture of gaining control of the electronic device, the control unit  112  is configured to approve the second object  120  to gain control over the electronic device. 
         [0053]    When an object  116 ,  120  is approved of the control over the electronic device  114 , further gesture inputs from the object in control are used for controlling the electronic device  114 . The control unit  112  may be adapted to use the coordinate system for interpreting the gesture inputs and translate them into control signals which are sent to the electronic device  114  in order to control the electronic device  114 . This coordinate system may advantageously be determined based on the gesture input for gaining control over the electronic device. This will further be explained in conjunction with  FIGS. 2 b  and 4 b    below. 
         [0054]      FIGS. 2 a - b    show by way of example a gesture for gaining control over the electronic device, i.e. a gesture corresponding to the first predetermined gesture in the memory discussed in conjunction with  FIG. 1  above. In  FIG. 2 a   , the start position of the exemplary gesture is shown. The gesture is performed by the first object  116  which in this example corresponds to two hands  204 ,  206 . The start position corresponds to the two hands being in abutment with each other, wherein the palm of the first hand  204  is pressed against the palm of the second hand  206 . This is an advantageous starting position since it is a very unusual position and thus reduces the risk of performing the gesture shown in  FIGS. 2 a - b    by mistake. In  FIG. 2 b   , the gesture is completed by moving the hands  204 ,  206  in opposite directions, such that a space is formed between the first hand  204  and the second hand  206 . Since this gesture corresponds to the first predetermined gesture, the object  116 , i.e. the hands  204 ,  206  are given the control over the electronic device by the control unit. 
         [0055]    In the space between the two sub-objects  204 ,  206 , a virtual object  208  is shown. This virtual object  208  may be seen as reference object for any subsequent gestures formed by the first object  116  for controlling the electronic device. Inside the virtual object  208 , a representation of the coordinate system  202  is shown. This coordinate system  202  is used by the control unit for interpreting the gesture inputs such that the control unit translates the gesture inputs into control signals which are sent to the electronic device  114  in order to control the electronic device  114  as described above. The coordinate system  202  may be a 2D system or a 3D system. 
         [0056]      FIG. 3  describe a gesture for releasing the control over the electronic device. In this example, the gesture corresponds to moving the hands  204 ,  206  such that the palms of the hands  204 ,  206  face the floor. By performing this gesture, the first object  116  are released from control over the electronic device by the control unit. 
         [0057]    In other words,  FIGS. 2 a - b    and  FIG. 3  describe an embodiment where the first object  116  comprises two objects  204 ,  206 , and wherein the first predetermined gesture and the second predetermined gesture corresponds to a gesture input of both of said two objects  204 ,  206 . 
         [0058]    Moreover, as can be seen in  FIGS. 2 a - b    and  3 , the first predetermined gesture comprises a predetermined gesture corresponding to a gesture input from two objects  204 ,  206  and also the second predetermined gesture comprises a predetermined gesture corresponding to a gesture input from two objects  204 ,  206 . 
         [0059]      FIGS. 4 a - b    show by way of example a gesture for gaining control over the electronic device, i.e. a gesture corresponding to the first predetermined gesture in the memory discussed in conjunction with  FIG. 1  above. In  FIG. 4 a   , the start position of the exemplary gesture is shown. The gesture is performed by the first object  116  which in this example corresponds to a single hand  402 . The start position corresponds to the hand  402  being positioned with its palm facing the floor. In  FIG. 4 b   , the gesture is completed by turning the hand  402  such that the palm of the hand  402  is turned upwards. Since this gesture corresponds to the first predetermined gesture, the object  116 , i.e. the hand  402  is given the control over the electronic device by the control unit. 
         [0060]    In the space above the palm of the hand  402 , a virtual object  208  is show. This virtual object may be seen as a reference object for any subsequent gestures formed by the first object  116  for controlling the electronic device. Inside the virtual object  208 , a representation of the coordinate system  202  is shown. This coordinate system  202  is used by the control unit for interpreting the gesture inputs such that the control unit translates the gesture inputs into control signals which are sent to the electronic device in order to control the electronic device as described above. 
         [0061]      FIG. 5  describe a gesture for releasing the control over the electronic device. In this example, the gesture corresponds to turning the hand  402  such that the palm of the hand  402  faces the floor. By performing this gesture, the first object  116  are released from control over the electronic device by the control unit. 
         [0062]      FIG. 6  shows by way of example a method for controlling the electronic device with gesture inputs. The method is explained in conjunction with the system shown in  FIG. 1 . 
         [0063]    The method starts with the control unit  112  receiving S 402  a gesture input from an object  116 ,  120 . Firstly, it is decided S 404  if an object other than the object from which the gesture input is received is in control over the electronic device. If this is the case, the gesture input is ignored S 405  by the control unit  112 . Consequently, gesture inputs from objects will be ignored as long as an object other than the object(s) from which the gesture inputs are received is in control over the electronic device. 
         [0064]    On the other hand, if no such other object is in control over the electronic device, the next step is to decide S 406 , by the control unit, if the object  116 ,  120  from which the gesture input is received is in control of the electronic device  114 . If the object  116 ,  120  in fact is in control over the electronic device  114 , the control unit  112  continues by comparing the gesture input with predetermined gestures, for example stored in the memory  110 . If the received gesture input corresponds to a predetermined gesture of releasing control of the electronic device  114 , the control unit  112  releases S 416  the object  116 ,  120  from the control over the electronic device  114 . If the gesture do not corresponds to predetermined gesture of releasing control of the electronic device  114 , the gesture input is interpreted, possibly by using a coordinate system as described in conjunction with  FIGS. 2 b  and 4 b   , by comparing the gesture input with further predetermined gestures stored in the memory  110 , and the interpretation is then translated to a control signal sent to the electronic device  114  in order to control S 418  the electronic device. 
         [0065]    However, if it is decided S 406  that the object  116 ,  120  from which the gesture input is not in control over the electronic device  114 , the next step is to check S 408 , by the control unit  112 , if the received gesture input corresponds to a predetermined gesture, stored in memory  110 , of gaining control of the electronic device  114 . If it is decided that the received gesture input do not correspond to the predetermined gesture of gaining control of the electronic device  114 , the gesture input is ignored S 409  by the control unit  112 . 
         [0066]    However, if the received gesture input is determined S 408  to correspond to the predetermined gesture of gaining control of the electronic device, the control  112  unit is configured to approve S 410  the object  116 ,  120  to gain control over the electronic device  114 . 
         [0067]    Finally, control unit is configured to determine a position in 3d space for the gesture input and to set S 412  the position in 3d space as a origin in a 3d coordinate system which will be used as described in conjunction with step S 418 . 
         [0068]    The person skilled in the art realizes that the present invention by no means is limited to the order of the steps in the exemplary embodiment of the method described above. On the contrary, variations are possible within the scope of the appended claims. For example, the step S 404  of checking if another object is already in control and the step of checking S 406  if the object from which the gesture input is received already is in control may be performed in different order such that step S 406  is performed prior to step S 404 .