Patent Publication Number: US-2021186331-A1

Title: Shoe-type device and method of controlling the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims under 35 U.S.C. § 119 to Korean Patent Application No. 10-2019-0173847 filed on Dec. 24, 2019, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference in their entirety. 
     BACKGROUND 
     1. Field 
     At least one example embodiment relates to a shoe-type device and a technology for controlling the shoe-type device. 
     2. Description of the Related Art 
     A user wears shoes in daily life. The shoes have a basic function of protecting the feet of the user comfortably and safely. Recently, shoes having a special function in addition to such a basic function have been developed and released. For example, there are various types of shoes, for example, shoes that automatically provide an electric stimulus to soles of the feet of a user when the user walks with the shoes on, and shoes that detect a gait pattern of a user through a sensor. As such, shoes have evolved into a wearable device having various advanced functions. 
     SUMMARY 
     Some example embodiments relate to a shoe-type device. 
     In some example embodiments, the shoe-type device includes a vibrator configured to generate a vibration; a pressure sensor under the vibrator, the pressure sensor configured to measure a measured pressure; and a controller configured to control an intensity of the vibration generated by the vibrator based on the measured pressure. 
     In some example embodiments, at least a portion of the pressure sensor overlaps the vibrator in a direction vertical to a bottom surface of the shoe-type device. 
     In some example embodiments, the pressure sensor completely overlaps an area of the vibrator in the direction vertical to the bottom surface of the shoe-type device. 
     In some example embodiments, the vibrator completely overlaps an area of the pressure sensor in the direction vertical to the bottom surface of the shoe-type device. 
     In some example embodiments, the pressure sensor and the vibrator form a vertical layer structure and have a same center position in a first direction. 
     In some example embodiments, the pressure sensor is attached to an underside of the vibrator. 
     In some example embodiments, the vibrator and the pressure sensor are integrally formed. 
     In some example embodiments, the controller is configured to set a vibration frequency of a vibration generated by the vibrator different from a sensing frequency of the pressure sensor. 
     In some example embodiments, the controller is configured to control the vibrator such that the intensity of the vibration decreases, in response to a decrease in the measured pressure. 
     In some example embodiments, the controller is configured to control the vibrator such that the intensity of the vibration increases, in response to an increase in the measured pressure. 
     In some example embodiments, the controller is configured to, set the intensity of the vibration as a first intensity, in response to the measured pressure being a first pressure, and set the intensity of the vibration as a second intensity greater than the first intensity, in response to the measured pressure being a second pressure greater than the first pressure. 
     In some example embodiments, the controller is configured to determine the intensity of the vibration based on the measured pressure and pressure-vibration intensity conversion information. 
     In some example embodiments, the vibrator is configured to generate the vibration such that the intensity of the vibration is less than a sensory threshold of a user wearing the shoe-type device. 
     In some example embodiments, the vibrator includes a first vibrator and a second vibrator, the first vibrator configured to generate a vibration at a position corresponding to a forefoot of a foot of a user, and the second vibrator configured to generate a vibration at a position corresponding to a rearfoot of the foot of the user, and the pressure sensor includes a first pressure sensor and a second pressure sensor, the first pressure sensor being under the first vibrator; and the second pressure sensor being under the second vibrator. 
     In some example embodiments, the controller is configured to, determine an intensity of a first vibration generated by the first vibrator based on a pressure measured by the first pressure sensor; and determine an intensity of a second vibration generated by the second vibrator based on a pressure measured by the second pressure sensor. 
     In some example embodiments, the controller is configured to control the first vibrator and the second vibrator such that the intensity of the first vibration and the intensity of the second vibration differ from each other. 
     Some example embodiments relate to a method of controlling a shoe-type device, the shoe-type device including a vibrator, a pressure sensor under the vibrator, and a controller. 
     In some example embodiments, the method includes measuring, via the pressure sensor, a measured pressure; and controlling, by the controller, an intensity of a vibration generated by the vibrator based on the measured pressure. 
     In some example embodiments, at least a portion of the pressure sensor overlaps the vibrator in a direction vertical to a bottom surface of the shoe-type device. 
     In some example embodiments, the controlling includes controlling the vibrator such that the intensity of the vibration decreases, in response a decrease in the measured pressure; and controlling the vibrator such that the intensity of the vibration increases, in response to an increase in the measured pressure. 
     In some example embodiments, the vibrator includes a first vibrator and a second vibrator, the first vibrator configured to generate a vibration at a position corresponding to a forefoot of a foot of a user, and the second vibrator configured to generate a vibration at a position corresponding to a rearfoot of the foot of the user, and the pressure sensor includes a first pressure sensor and a second pressure sensor, the first pressure sensor being under the first vibrator, and the second pressure sensor being under the second vibrator. The controlling may include determining an intensity of a first vibration generated by the first vibrator based on a pressure measured by the first pressure sensor; and determining an intensity of a second vibration generated by the second vibrator based on a pressure measured by the second pressure sensor. 
     Some example embodiments relate to an insole of a shoe-type device. 
     In some example embodiments, the insole includes an insole body insertable in the shoe-type device; a vibrator installed in the insole body, the vibrator configured to generate a vibration; and a pressure sensor under the vibrator in the insole body, the pressure sensor configured to measure a measured pressure. 
     In some example embodiments, at least a portion of the pressure sensor overlaps the vibrator in a direction vertical to a bottom surface of the insole. 
     In some example embodiments, the vibrator includes a first vibrator and a second vibrator, the first vibrator configured to generate a vibration at a position corresponding to a forefoot of a foot of a user, and the second vibrator configured to generate a vibration at a position corresponding to a rearfoot of the foot of the user, and the pressure sensor includes a first pressure sensor and a second pressure sensor, the first pressure sensor being under the first vibrator, and the second pressure sensor being under the second vibrator. 
     In some example embodiments, an intensity of the vibration generated by the vibrator is based on the measured pressure. 
     In some example embodiments, the intensity of the vibration is based on the measured pressure such that the intensity of the vibration varies directly with the measured pressure. 
     In some example embodiments, the insole further includes a connector configured to connect the vibrator and the pressure sensor to a controller. 
     In some example embodiments, the connector is configured to at least partially protrude from the insole body downwards towards an outsole of the shoe-type device to contact a terminal of the controller. 
     In some example embodiments, the insole further includes the controller connected to the vibrator and the pressure sensor via the connector, the controller configured to control an intensity of the vibration generated by the vibrator based on the measured pressure. 
     Additional aspects of example embodiments will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects will become apparent and more readily appreciated from the following description of example embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a perspective view of an example of a shoe-type device according to at least one example embodiment; 
         FIG. 2  is an exploded perspective view of an example of a shoe-type device according to at least one example embodiment; 
         FIG. 3  is a cross-sectional view of an example of a shoe-type device according to at least one example embodiment; 
         FIG. 4  is a plan view illustrating an example of a positional relationship between electronic devices of a shoe-type device and a foot of a user according to at least one example embodiment; 
         FIGS. 5A through 5E  are diagrams illustrating examples of an arrangement relationship between a vibrator and a pressure sensor according to at least one example embodiment; 
         FIG. 6  is a diagram illustrating an example of vibration control of a shoe-type device for a forefoot and a rearfoot of a user according to at least one example embodiment; 
         FIGS. 7A through 7D  are diagrams illustrating examples of adjusting a vibration intensity of a vibrator based on a magnitude of a pressure measured by a pressure sensor according to at least one example embodiment; 
         FIG. 8  is a flowchart illustrating an example of a method of controlling a shoe-type device according to at least one example embodiment; 
         FIG. 9  is a diagram illustrating an example of a control device of a shoe-type device according to at least one example embodiment; and 
         FIG. 10  is a diagram illustrating an example of a walking assistance device according to at least one example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, some example embodiments will be described in detail with reference to the accompanying drawings. Regarding the reference numerals assigned to the elements in the drawings, it should be noted that the same elements will be designated by the same reference numerals, wherever possible, even though they are shown in different drawings. Also, in the description of embodiments, detailed description of well-known related structures or functions will be omitted when it is deemed that such description will cause ambiguous interpretation of the present disclosure. 
     It should be understood, however, that there is no intent to limit this disclosure to the particular example embodiments disclosed. On the contrary, example embodiments are to cover all modifications, equivalents, and alternatives falling within the scope of the example embodiments. Like numbers refer to like elements throughout the description of the figures. 
     In addition, terms such as first, second, A, B, (a), (b), and the like may be used herein to describe components. Each of these terminologies is not used to define an essence, order or sequence of a corresponding component but used merely to distinguish the corresponding component from other component(s). It should be noted that if it is described in the specification that one component is “connected,” “coupled,” or “joined” to another component, a third component may be “connected,” “coupled,” and “joined” between the first and second components, although the first component may be directly connected, coupled or joined to the second component. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the,” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved. 
     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 the disclosure of this application pertains. Terms, such as those defined in commonly used dictionaries, are to be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art, and are not to be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Also, in the description of example embodiments, detailed description of structures or functions that are thereby known after an understanding of the disclosure of the present application will be omitted when it is deemed that such description will cause ambiguous interpretation of the example embodiments. 
     Various example embodiments will now be described more fully with reference to the accompanying drawings in which some example embodiments are shown. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. 
     A shoe-type device to be described hereinafter may include an electronic device configured to generate a vibration. For example, the shoe-type device may include a vibrator that may generate a physical vibration based on a control signal. The vibrator may be embedded in the shoe-type device, or an insole, and provide a user wearing the shoe-type device with a stimulus of a magnitude less than a sensory threshold of the user. The sensory threshold refers to a minimum magnitude of a stimulus that activates cells of the plantar sole of the user. The vibrator may generate the vibration having an intensity less than or equal to a threshold of a tactile sensation felt by a plantar sole of a foot of the user, thereby triggering stochastic resonance. The stochastic resonance refers to a phenomenon where a level of sensitivity to an observation target signal is improved when, to a measuring device or a sensory organ having a fixed sensory threshold, white noise of a magnitude less than or equal to the sensory threshold is applied. For example, the vibration generated by the vibrator of the shoe-type device may amplify a tactile signal to be transferred to the plantar sole of the foot of the user through the stochastic resonance, and thus the user may feel more sensitively a sensation on the plantar sole of the foot of the user. Thus, the shoe-type device may help those who may not normally feel a sensation due to a reduced sensory ability of their feet. 
     Hereinafter, example embodiments will be described in detail with reference to the accompanying drawings, and like reference numerals in the drawings refer to like elements throughout. 
       FIG. 1  is a perspective view of an example of a shoe-type device according to at least one example embodiment.  FIG. 2  is an exploded perspective view of an example of a shoe-type device with an insole body being separately shown according to at least one example embodiment.  FIG. 3  is a cross-sectional view of an example of a shoe-type device according to at least one example embodiment. 
     Referring to  FIGS. 1 through 3 , a shoe-type device  1  includes a sole  10 , a control device  20 , and an upper  90 . The sole  10  includes an outsole  11 , a midsole  12 , and an insole  13 . Hereinafter, a longitudinal direction of the shoe-type device  1  will indicate a y-axis direction, a width direction of the shoe-type device  1  will indicate an x-axis direction, and a height direction of the shoe-type device  1  will indicate a z-axis direction. The shoe-type device  1  is provided in a form of a shoe, for example. However, the form of the shoe-type device  1  is not limited to the foregoing example. For example, the shoe-type device  1  may be provided in a form of a sock, and be applied to an exercise assist robot. 
     The outsole  11  forms at least a portion of a bottom part of the shoe-type device  1 . For example, the outsole  11  includes a bottom surface that is brought into contact with the ground when a user wears the shoe-type device  1 . Although the outsole  11  and the midsole  12  are illustrated as being separate, the outsole  11  and the midsole  12  may be provided in an integral form. The midsole  12  forms at least a portion of an outer lower shape of the shoe-type device  1 . The insole  13  is provided inside the upper  90  and disposed on the midsole  12 . The insole  13  includes a surface that is brought into contact with a plantar sole of a foot of the user when the user wears the shoe-type device  1 , and is detachable from the midsole  12 . 
     The insole  13  includes an insole body  131 , a support layer  132 , an electronic device, a connecting line  134 , and a connector  135 . The insole body  131  is disposed on a top surface of the midsole  12 , and may be provided in various shapes. The support layer  132  is provided on an inner side of the insole body  131  and may support the electronic device and the connecting line  134 . The connecting line  134  may electrically connect the electronic device and the control device  20 . The connector  135  may electrically connect each electronic device to the control device  20 . 
     The electronic device is disposed on a top surface of the support layer  132 . The electronic device and the support layer  132  are disposed as a whole in the insole body  131 . However, examples are not limited to the illustrated example, and a portion of the electronic device may be exposed to an outside of the insole body  131 . 
     The electronic device includes at least one vibrator, for example, a vibrator  133   a  and a vibrator  133   b  as illustrated, and at least one pressure sensor, for example, a pressure sensor  143   a  and a pressure sensor  143   b  as illustrated. The vibrator may include, for example, a piezoelectric motor (or simply piezo motor) or an eccentric vibration motor. The vibrator may generate a physical vibration having an intensity less than or equal to a set maximum vibration intensity. The intensity may change irregularly as in noise. The pressure sensor, which is a sensor configured to measure a pressure applied thereto, may sense a foot pressure to be transferred from the plantar sole of the foot of the user when the user wears the shoe-type device  1 . The pressure sensor may be a piezoelectric pressure sensor (or simply piezo pressure sensor) or a force sensitive resistor (FSR) pressure sensor, and be embodied in a form of a film. 
     The pressure sensor may not be disposed separately from the vibrator, but be disposed under where the vibrator is disposed. For example, as illustrated, the pressure sensor, for example, the pressure sensors  143   a  and  143   b , may overlap the vibrator, for example, the vibrators  133   a  and  133   b , in at least a portion in a direction vertical to a bottom surface of the shoe-type device  1 . As such, the pressure sensor and the vibrator may form a vertical layer structure. 
     According to an example, the electronic device may further include another sensor, for example, an inertial sensor such as an acceleration sensor and a gyro sensor. The inertial sensor may be used to measure a movement of the shoe-type device  1  or a movement of the user wearing the shoe-type device  1 . 
     The control device  20  may be electrically connected to the electronic device, and thus receive sensor data from the pressure sensor or another sensor included in the electronic device. In addition, the control device  20  may transmit, to the vibrator, a control signal for controlling an operation of the vibrator. 
     The control device  20  includes a case  21 , a connecting portion  22 , a battery  23 , and a controller  24 . The case  21  is provided in a form corresponding to a receiving groove  121  formed in the midsole  12 . The connecting portion  22  includes a terminal to be electrically connected to the connecting line  134 , and is disposed on an upper side of the case  21 . The battery  23  may provide power that is needed for the shoe-type device  1  to operate. For example, the battery  23  may provide power to the electronic device and the controller  24 , and include a rechargeable battery. 
     The controller  24  includes at least one processor, and may control an operation of the shoe-type device  1 . 
     The controller  24  may generate a control signal to control an operation of the electronic device. For example, the controller  24  may generate one or more control signals for controlling respective ones of the vibrators based on a pressure measured by the pressure sensor, and one or more control signals for adjusting the number of vibrations to be generated by the respective ones of the vibrators and/or a maximum vibration intensity of the respective ones of the vibrators. 
     For example, the controller  24  associated with the shoe-type device  1  may include processing circuitry including, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit, a microprocessor, application-specific integrated circuit (ASIC), etc. The processing circuitry may be special purpose processing circuitry that configures the shoe-type device  1  to set an intensity of a vibration generated by the vibrators to be directly related to a magnitude of pressure measured by the pressure sensors. Therefore, the special purpose controller  24  may improve the functioning of the shoe-type device  1  by controlling a vibration intensity of the vibrators based on a pressure as described above, and thus relieve inconvenience a user may experience due to an excessive vibration. 
       FIG. 4  is a plan view illustrating an example of a relationship between relative positions of an electronic device and a foot of a user according to at least one example embodiment. 
     Referring to  FIG. 4 , a shoe-type device includes a front vibrator  133   a  disposed in a front portion of the support layer  132 , a rear vibrator  133   b  disposed in a rear portion of the support layer  132 , a front pressure sensor  143   a  disposed under the front vibrator  133   a , and a rear pressure sensor  143   b  disposed under the rear vibrator  133   b . The front vibrator  133   a  may generate a vibration or vibration noise at a position corresponding to a forefoot of a foot of a user, and the rear vibrator  133   b  may generate a vibration or vibration noise at a position corresponding to a rearfoot of the foot of the user. Here, the forefoot may indicate an anterior sole portion of the foot, and the rearfoot may indicate a posterior sole portion of the foot. 
     According to an example embodiment, the controller  24  may determine an intensity of a vibration to be generated by the front vibrator  133   a  based on a pressure measured by the front pressure sensor  143   a , and an intensity of a vibration to be generated by the rear vibrator  133   b  based on a pressure measured by the rear pressure sensor  143   b.    
     An intensity of a vibration or a transfer characteristic of the vibration to be felt by the user may vary according to a change in pressure of a sole of the foot of the user while the user is wearing the shoe-type device  1 . For example, when the user is standing with the shoe-type device  1  on, a pressure to be applied to the sole of the foot of the user may be relatively great. In this example, a vibration of a greater intensity may need to be applied to the sole of the foot of the user. For another example, when the user is sitting or lying with the shoe-type device  1  on, a pressure to be applied to the sole of the foot of the user may be relatively smaller than that when the user is standing. In this example, a vibration of a smaller intensity may need to be applied to the sole of the foot of the user. As described above, a pressure on the sole and an intensity of a vibrator to be applied may have a close relationship. Thus, to determine a vibration intensity suitable for each of the vibrators  133   a  and  133   b , a more accurate pressure may need to be measured from a position at which each of the vibrators  133   a  and  133   b  is disposed. 
     The shoe-type device  1  may have the pressure sensors  143   a  and  143   b  under the vibrators  133   a  and  133   b , and thus effectively determine an intensity of a vibration corresponding to a position at which a pressure of the sole is measured. In addition, as the pressure sensors  143   a  and  143   b  are disposed under the vibrators  133   a  and  133   b , the vibrators  133   a  and  133   b  may naturally perform a function corresponding to a puck structure of the pressure sensors  143   a  and  143   b.    
       FIGS. 5A through 5E  are diagrams illustrating examples of an arrangement of a vibrator and a pressure sensor according to at least one example embodiment. 
     According to an example embodiment, a vibrator and a pressure sensor may form a vertical layer structure, and at least a portion of them may overlap each other in a direction vertical to a bottom surface of a shoe-type device. There may be various forms of the vertical layer structure formed between the vibrator and the pressure sensor. The vibrators  133   a ,  133   b  may be one of vibrators  512 ,  522 ,  532 ,  542  and  552 , and the pressure sensors  143   a ,  143   b  may be a corresponding one of pressure sensors  514 ,  524 ,  534 ,  544  and  554 , which are each discussed in more detail below. 
     Referring to  FIG. 5A , a vibrator  512  and a pressure sensor  514  have a same width, and a same center position in a first direction. For example, the vibrator  512  and the pressure sensor  514  may be arranged within a concentric circle in the first direction. The first direction may correspond to a z-axis direction or a direction vertical to a bottom surface of a shoe-type device. Referring to  FIG. 5B , a pressure sensor  524  completely overlaps a vibrator  522  in an area of the vibrator  522  in a direction vertical to a bottom surface of a shoe-type device. In such a case, the vibrator  522  may have a width greater than that of the pressure sensor  524 . Referring to  FIG. 5C , a vibrator  532  completely overlaps a pressure sensor  534  in an area of the pressure sensor  534  in a direction vertical to a bottom surface of a shoe-type device. In such a case, the pressure sensor  534  may have a width greater than that of the vibrator  532 . Referring to  FIG. 5D , dissimilar to what is illustrated in  FIG. 5A , a vibrator  542  and a pressure sensor  544  may not have a same center position in a first direction. Referring to  FIG. 5E , there are a plurality of pressure sensors  554  and  556  associated with a single vibrator  552 . In such a case, all the pressure sensors  554  and  556  may be disposed under a vibrator  552 , and at least a portion of them may overlap the vibrator  552  in a direction vertical to a bottom surface of a shoe-type device. 
     According to an example embodiment, a pressure sensor may be attached to a vibrator and may be under the vibrator. In addition, the vibrator and the pressure sensor may be provided in an integral form with the pressure sensor being disposed under the vibrator. That is, the vibrator and the pressure sensor may be embodied by a single module. 
       FIG. 6  is a diagram illustrating an example of vibration control of a shoe-type device for a forefoot and a rearfoot of a foot of a user according to at least one example embodiment. 
     Referring to  FIG. 6 , a shoe-type device includes a front vibrator  614  disposed at a position corresponding to a forefoot of a foot of a user, and a rear vibrator  612  disposed at a position corresponding to a rearfoot of the foot of the user. A front pressure sensor  624  is disposed under the front vibrator  614  and a rear pressure sensor  622  is disposed under the rear vibrator  612 . Here, a forefoot and a rearfoot may indicate an anterior sole portion of a foot and a posterior sole portion of the foot, respectively. 
     When the user is standing on a flat ground with the shoe-type device on, a pressure to be applied to the rearfoot may be generally greater than a pressure to be applied to the forefoot. In such a general case, a pressure to be sensed by the rear pressure sensor  622  may be greater than a pressure to be sensed by the front pressure sensor  624 , and thus a controller of the shoe-type device may control the front vibrator  614  and the rear vibrator  612  such that a vibration intensity of the rear vibrator  612  is greater than a vibration intensity of the front vibrator  614 . The controller may automatically control the vibration intensity of each of the front vibrator  614  and the rear vibrator  612  based on the pressure sensed by each of the front pressure sensor  624  and the rear pressure sensor  622 . Thus, the shoe-type device may effectively trigger stochastic resonance that increases sensitivity of a foot sole of the user based on a pressure on the foot sole of the user. 
       FIGS. 7A through 7D  are diagrams illustrating examples of adjusting a vibration intensity of a vibrator based on a magnitude of a pressure measured by a pressure sensor according to at least one example embodiment. 
       FIG. 7A  illustrates an example of linearly adjusting a vibration intensity of a vibrator based on a magnitude of a measured pressure.  FIGS. 7B and 7C  illustrate examples of non-linearly adjusting a vibration intensity of a vibrator based on a magnitude of a measured pressure.  FIG. 7D  illustrates non-continuously adjusting a vibration intensity of a vibrator based on a magnitude of a measured pressure. 
     When a magnitude of a measured pressure is small, a shoe-type device may set an intensity of a vibration to be generated by a vibrator to be small based on, for example, the pressure-intensity relationship illustrated in one of  FIGS. 7A to 7D . When a magnitude of a measured pressure is great, the shoe-type device may set an intensity of a vibration to be generated by the vibrator to be great based on, for example, the pressure-intensity relationship illustrated in one of  FIGS. 7A to 7D . Thus, the shoe-type device may control a vibration intensity of the vibrator based on a pressure as described above, and thus relieve inconvenience a user may experience due to an excessive vibration. 
       FIG. 8  is a flowchart illustrating an example of a method of controlling a shoe-type device according to at least one example embodiment. 
     Referring to  FIG. 8 , in operation  810 , the control device  20  of the shoe-type device  1  measures a pressure using the pressure sensors  143   a ,  143   b  disposed under respective ones of the vibrators  133   a ,  133   b.    
     In operation  820 , the control device  20  of the shoe-type device  1  adjusts an intensity of a vibration to be generated by the vibrators  133   a ,  133   b  based on the pressure measured in operation  810 . 
     According to an example embodiment, when the measured pressure increases, the control device  20  may control the vibrators  133   a ,  133   b  such that an intensity of the vibration to be generated by the vibrators  133   a ,  133   b  increases. Conversely, when the measured pressure decreases, the control device  20  may control the vibrators  133   a ,  133   b  such that an intensity of the vibration to be generated by the vibrator decreases. The control device  20  may adjust a vibration intensity of the vibrator  20  by controlling an output of a motor included in the vibrators  133   a ,  133   b . The control device  20  may automatically adjust a vibration intensity of the vibrators  133   a ,  133   b  based on a change in measured pressure. 
     According to an example embodiment, when the shoe-type device  1  includes the first vibrator  133   a  configured to generate a vibration at a position corresponding to a forefoot of a foot of a user, the second vibrator  133   b  configured to generate a vibration at a position corresponding to a rearfoot of the foot of the user, the first pressures sensor  143   a  disposed under the first vibrator  133   a , and the second pressure sensor  143   b  disposed under the second vibrator  133   b , the control device  20  may determine an intensity of a first vibration to be generated by the first vibrator  133   a  based on a pressure measured by the first pressure sensor  143   a  and determine an intensity of a second vibration to be generated by the second vibrator  133   b  based on a pressure measured by the second pressure sensor  143   b . The intensity of the first vibration and the intensity of the second vibration may differ from each other. 
     A magnitude of a measured foot sole pressure and a vibration intensity of the vibrator to be set based on pressure may have a continuous or non-continuous relationship, or a linear or non-linear relationship for example, as illustrated in  FIGS. 7A to 7D . According to an example embodiment, the control device  20  may determine a vibration intensity corresponding to a measured pressure based on desired (or, alternatively, predefined) pressure-vibration intensity conversion information, and control the vibrators  133   a ,  133   b  such that a vibration of the determined vibration intensity is generated. 
     The shoe-type device  1  may adjust a vibration intensity of the vibrators  133   a ,  133   b  based on a pressure measured from a sole of a foot of the user, and thus reduce a battery consumption of the shoe-type device  1  and effectively trigger stochastic resonance. In addition, when a pressure of the sole of the foot of the user is relatively low, the shoe-type device  1  may apply a vibration of a desirable intensity corresponding to such a low pressure to the sole of the foot of the user, and thus prevent the user from feeling uncomfortableness due to a vibration intensity that is unnecessarily great. 
     In addition, a vibration frequency of a vibration to be generated by the vibrators  133   a ,  133   b  may be different from a sensing frequency of the pressure sensors  143   a ,  143   b  for pressure sensing, and thus the vibration generated by the vibrators  133   a ,  133   b  may not have a significant influence on the pressure sensing even though the pressure sensor is disposed under the vibrator s  133   a ,  133   b . According to an example, the control device  20  may use a filter to filter out a noise component that occurs due to a vibration of the vibrators  133   a ,  133   b  from a pressure signal measured by the pressure sensors  143   a ,  143   b.    
     In some example embodiments, the shoe-type device  1  may adjust the vibration intensity of the vibrator based on the measured pressure and the pressure-vibration intensity conversion information such that the vibration intensity is within an allowed intensity range. 
     For example, in some example embodiments, the shoe-type device  1  may set the allowed intensity range based on parameters associated with the user. For example, the shoe-type device  1  may determine a weight of the user based on, for example, the pressure exerted on the pressure sensors  143   a ,  143   b  while the user is stationary, and determine the allowed intensity range based on the weight of the user. As another example, the shoe-type device  1  may be configured to perform an initialization operation to determine the sensitivity of the user by providing stimulus to the plantar sole of the user via the vibrators  133   a ,  133   b  and receive feedback from the user indicating a minimum acceptable intensity and a maximum acceptable intensity, determine the allowed intensity range based on the input minimum acceptable intensity and maximum acceptable intensity, and store the allowed intensity range in a memory. As another example, the shoe-type device  1  may over time learn over the minimum intensity provided to the user in which the user responds to the stimulus, and store the minimum intensity as the minimum acceptable intensity of the allowed intensity range. 
       FIG. 9  is a diagram illustrating an example of a control device of a shoe-type device according to at least one example embodiment. 
     Referring to  FIG. 9 , a control device  900  of the shoe-type device  1  includes a pressure sensor  910 , a vibrator  920 , and a controller  930 . The control device  900  may be embedded in the shoe-type device  1  to operate therein. 
     The vibrator  920  may generate a vibration under the control of the controller  930 . According to an example embodiment, the vibrator  920  may generate a vibration of an intensity less than a sensory threshold of a user wearing the shoe-type device. The pressure sensor  910  may be disposed under the vibrator  920  and measure a pressure. According to an example embodiment, the vibrator  920  and the pressure sensor  910  may be disposed in an insole of the shoe-type device  1  such that the vibrator  920  corresponds to the vibrators  133   a ,  133   b  and the pressure sensor  910  corresponds to the pressure sensors  143   a ,  143   b.    
     At least a portion of the pressure sensor  910  may overlap the vibrator  920  in a direction vertical to a bottom surface of the shoe-type device  1 . According to an example embodiment, the pressure sensor  910  may completely overlap an area of the vibrator  920  in the direction vertical to the bottom surface of the shoe-type device, or the vibrator  920  may completely overlap an area of the pressure sensor  910  in the direction vertical to the bottom surface of the shoe-type device. According to an example, the pressure sensor  910  may be attached to the vibrator  920  under the vibrator  920 , and the vibrator  920  and the pressure sensor  910  may be provided in an integral form. 
     The controller  930  may control each component of the shoe-type device  1 . The controller  930  may control an intensity of a vibration to be generated by the vibrator  920  based on a pressure measured by the pressure sensor  910 . The controller  930  may correspond to the control device  20 . 
     For example, the controller  930  associated with the shoe-type device  1  may include processing circuitry including, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit, a microprocessor, application-specific integrated circuit (ASIC), etc. The processing circuitry may be special purpose processing circuitry that configures the shoe-type device  1  to set an intensity of a vibration generated by the vibrator  920  to be directly related to a magnitude of pressure measured by the pressure sensor  910 . Therefore, the special purpose controller  930  may improve the functioning of the shoe-type device  1  by controlling a vibration intensity of the vibrator  920  based on a pressure as described above, and thus relieve inconvenience a user may experience due to an excessive vibration. 
     For example, when the measured pressure increases, the controller  930  may control the vibrator  920  such that an intensity of the vibration to be generated by the vibrator  920  increases. When the measured pressure decreases, the controller  930  may control the vibrator  920  such that an intensity of the vibration to be generated by the vibrator  920  decreases. For example, when the measured pressure is a first pressure, the controller  930  may set a vibration intensity to be a first intensity. When the measured pressure is a second pressure which is greater than the first pressure, the controller  930  may set a vibration intensity to be a second intensity which is greater than the first intensity. 
     According to an example embodiment, the controller  930  may use desired (or, alternatively, predefined) pressure-vibration intensity conversion information to determine a vibration intensity of the vibrator  920  based on a magnitude of a measured pressure. The pressure-vibration intensity conversion information may be information that defines a corresponding relationship between a magnitude of a pressure and an intensity of a vibration, and be defined in a form of a lookup table. 
     The controller  930  may individually control a vibration intensity of each vibrator  920  based on a pressure magnitude of each pressure sensor  910  disposed in the shoe-type device. For example, the controller  930  may determine an intensity of a first vibration to be generated by a first vibrator  920  based on a pressure measured by a first pressure sensor  910 , and determine an intensity of a second vibration to be generated by a second vibrator  920  based on a pressure measured by a second pressure sensor  910 . 
       FIG. 10  is a diagram illustrating an example of a walking assistance device according to at least one example embodiment. 
     Referring to  FIG. 10 , a walking assistance device may be in communication with left and right shoe-type devices  1 -L and  1 -R, which each correspond to the shoe-type device  1 . 
     In some example embodiments, the walking assistance device may include a driving portion  1010 , a sensor portion  1020 , an inertial measurement unit (IMU) sensor  1030 , and a controller  1040 . 
     In some example embodiments, the shoe-type devices  1 -L,  1 -R may be in communication with the walking assistance apparatus worn by the user, and may provide information to the walking assistance apparatus indicating the pressure measured by the pressure sensors  143   a ,  143   b  and/or may control the vibrators  133   a ,  133   b  based on received instructions from the walking assistance apparatus. 
     In some example embodiments, the shoe-type devices  1 -L,  1 -R may measure a pressure applied to the sole of the user using the pressure sensors  143   a ,  143   b , and detect a center of pressure (COP) therefrom. The shoe-type device  1  may be in communication with a walking assistance apparatus worn by the user, and instruct the walking assistance apparatus to output an assistance force that re-balances pressures applied to the sole of the user based on the center of pressure (COP). 
     The units and/or modules described herein may be implemented using hardware components and software components. For example, the hardware components may include microphones, amplifiers, band-pass filters, audio to digital convertors, and processing devices. A processing device may be implemented using one or more hardware device configured to carry out and/or execute program code by performing arithmetical, logical, and input/output operations. The processing device(s) may include a processor, a controller and an arithmetic logic unit, a digital signal processor, a microcomputer, a field programmable array, a programmable logic unit, a microprocessor or any other device capable of responding to and executing instructions in a defined manner. The processing device may run an operating system (OS) and one or more software applications that run on the OS. The processing device also may access, store, manipulate, process, and create data in response to execution of the software. For purpose of simplicity, the description of a processing device is used as singular; however, one skilled in the art will appreciated that a processing device may include multiple processing elements and multiple types of processing elements. For example, a processing device may include multiple processors or a processor and a controller. In addition, different processing configurations are possible, such a parallel processors. 
     The software may include a computer program, a piece of code, an instruction, or some combination thereof, to independently or collectively instruct and/or configure the processing device to operate as desired, thereby transforming the processing device into a special purpose processor. Software and data may be embodied permanently or temporarily in any type of machine, component, physical or virtual equipment, computer storage medium or device, or in a propagated signal wave capable of providing instructions or data to or being interpreted by the processing device. The software also may be distributed over network coupled computer systems so that the software is stored and executed in a distributed fashion. The software and data may be stored by one or more non-transitory computer readable recording mediums. 
     The methods according to the above-described example embodiments may be recorded in non-transitory computer-readable media including program instructions to implement various operations of the above-described example embodiments. The media may also include, alone or in combination with the program instructions, data files, data structures, and the like. The program instructions recorded on the media may be those specially designed and constructed for the purposes of example embodiments, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of non-transitory computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROM discs, DVDs, and/or Blue-ray discs; magneto-optical media such as optical discs; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory (e.g., USB flash drives, memory cards, memory sticks, etc.), and the like. Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The above-described devices may be configured to act as one or more software modules in order to perform the operations of the above-described example embodiments, or vice versa. 
     A number of example embodiments have been described above. Nevertheless, it should be understood that various modifications may be made to these example embodiments. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Accordingly, other implementations are within the scope of the following claims.