Patent Description:
In a rapidly aging society, a growing number of people has experienced inconvenience and pain from joint problems and an interest in walking assistance devices that enable the elderly and/or patients having joint problems to walk with less effort has been heightened. In addition, walking assistance devices for intensifying muscular strength of human bodies are being developed.

<CIT> discloses a wearable device comprising: a motor; a motor driver circuit; a sensor; and a processor configured to: obtain a joint angle of a user using the sensor and provide a control signal so as to perform control such that a control state of the motor driver circuit is switched between a first control state in which the motor generates a force and a second control state in which the motor does not generate a force. The known device is controlled not only for assistance force generation, but also for resistance force generation.

In view of this, a wearable device and a method thereof are needed, which allow to intensify people's muscular strength.

According to a first aspect, a wearable device is provided as defined in the appended claim <NUM>.

Preferred embodiments of the wearable device are defined in the appended dependent claims <NUM> to <NUM>.

According to a second aspect, a method of controlling a wearable device is provided as defined in the appended claim <NUM>.

Hereinafter, example embodiments will be described in detail with reference to the accompanying drawings. However, various alterations and modifications may be made to the example embodiments. Here, the example embodiments are not meant to be limited by the descriptions of the present disclosure. The example embodiments should be understood to include all changes, equivalents, and replacements within the idea and the technical scope of the disclosure.

The terminology used herein is for the purpose of describing particular example embodiments only and is not to be limiting of the example embodiments.

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 example embodiments belong. It will be further understood that terms, such as those defined in commonly-used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

When describing the example embodiments with reference to the accompanying drawings, like reference numerals refer to like components and a repeated description related thereto will be omitted. In the description of example 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.

Also, in the description of the components, terms such as first, second, A, B, (a), (b) or the like may be used herein when describing components of the example embodiments. These terms are used only for the purpose of discriminating one component from another component, and the nature, the sequences, or the orders of the components are not limited by the terms. When one component is described as being "connected", "coupled", or "joined" to another component, it should be understood that one component can be connected or attached directly to another component, and an intervening component can also be "connected", "coupled", or "joined" to the components.

The same name may be used to describe a component included in one example embodiment and a component having a common function. Unless otherwise mentioned, the descriptions of the example embodiments may be applicable to the following example embodiments, and thus duplicated descriptions will be omitted for conciseness.

<FIG> are diagrams illustrating an example of a wearable device according to an example embodiment.

A wearable device <NUM> may be worn on a body (e.g., a leg, an arm, a waist, etc.) of a user to provide a resistance force to a movement (or exercise) of the user. The resistance force may be a force that hinders a movement of the user or provides a resistance to the movement of the user, and may represent a force acting in a direction opposite to a direction in which the user moves. The resistance force may also be referred to as an exercise load. According to implementation, the wearable device <NUM> may provide an assistance force to a movement of the user. The assistance force may be a force to assist a movement of the user, and may represent a force acting in the same direction as a direction in which the user moves.

Referring to <FIG>, the wearable device <NUM> includes a sensor <NUM>, a processor <NUM>, a motor driver circuit <NUM>, a motor <NUM>, a battery <NUM>, a memory <NUM>, and an input interface <NUM>. Although a single sensor <NUM>, a single motor driver circuit <NUM>, and a single motor <NUM> are illustrated in <FIG>, this is merely an example. For example, as shown in <FIG>, a wearable device <NUM>-<NUM> may include a plurality of sensors <NUM> and <NUM>-<NUM>, a plurality of motor driver circuits <NUM> and <NUM>-<NUM>, and a plurality of motors <NUM> and <NUM>-<NUM>. In addition, according to implementation, the wearable device <NUM> may include a plurality of processors. A number of motor driver circuits, a number of motors, or a number of processors may vary depending on a body part on which the wearable device <NUM> is to be worn. An example in which the wearable device <NUM>-<NUM> is worn on a hip is shown in <FIG>. In <FIG>, the motors <NUM> and <NUM>-<NUM> are located around a right hip joint and a left hip joint, respectively. Accordingly, the wearable device <NUM>-<NUM> may provide a resistance force to flexion and extension of each hip joint when a user walks. Here, the flexion may be a forward rotation of a hip joint, and the extension may be a backward rotation of a hip joint. There is no limitation to the example shown in <FIG>, and each of the motors <NUM> and <NUM>-<NUM> may be disposed to transmit a resistance force to adduction and abduction of each hip joint. Here, the abduction may indicate a movement away from a body of a user when the user moves laterally, and the adduction may indicate a movement closer to the body. If the user lies on his or her side and lifts a first leg, a hip joint of the first leg may be abducted, and if the first leg is lowered, the hip joint of the first leg may be adducted, which will be described below with reference to <FIG>. The motor <NUM> may be disposed to transmit a resistance force to each of adduction and abduction of the right hip joint.

The following descriptions of the sensor <NUM>, the motor driver circuit <NUM>, and the motor <NUM> are also applicable to the sensor <NUM>-<NUM>, the motor driver circuit <NUM>-<NUM>, and the motor <NUM>-<NUM> illustrated in <FIG>.

Referring back to <FIG>, the sensor <NUM> may include an encoder. The encoder may detect rotation information, for example, a rotation speed and a rotation position of a shaft. The encoder may include, for example, an absolute encoder. The absolute encoder may transmit a bit value corresponding to each rotation position of the shaft to the processor <NUM>, and the processor <NUM> may calculate a rotation angle of the shaft based on received bit values. For example, the absolute encoder may transmit a first bit value corresponding to a first rotation position to the processor <NUM> if a shaft of the absolute encoder is in the first rotation position, and may transmit a second bit value corresponding to a second rotation position to the processor <NUM> if the shaft is rotated to be in the second rotation position. The processor <NUM> may calculate a rotation angle of the shaft by subtracting an angle corresponding to the first bit value from an angle corresponding to the second bit value. According to an implementation, the absolute encoder may calculate the rotation angle of the shaft by subtracting the second rotation position from the first rotation position of the shaft, and transmit the calculated rotation angle to the processor <NUM>.

The encoder is not limited to the absolute encoder described above, and may include, for example, various encoders such as an incremental encoder, a magnetic encoder, and the like.

The type of the sensor <NUM> is not limited to the encoder, and the wearable device <NUM> may further include an acceleration sensor, a gyro sensor, or an inertial measurement unit (IMU) sensor.

When a user moves, the shaft of the encoder may be rotated by a movement of the user, and accordingly the rotation angle of the shaft of the encoder may correspond to a joint angle of the user. The rotation angle of the shaft of the encoder in the wearable device <NUM> may be used as a joint angle of a user. Hereinafter, for convenience of description, the rotation angle of the shaft of the encoder is expressed as a joint angle of a user.

The processor <NUM> may control an overall operation of the wearable device <NUM>.

The processor <NUM> may control the motor driver circuit <NUM> based on an operation mode of the wearable device <NUM>. The operation mode of the wearable device <NUM> may include a first resistance mode in which the motor <NUM> outputs a resistance force by receiving power from the battery <NUM>, and a second resistance mode in which the motor <NUM> outputs a resistance force instead of receiving power from the battery <NUM>.

In the first resistance mode, the processor <NUM> may control the motor driver circuit <NUM> such that the motor <NUM> may receive power from the battery <NUM>, and accordingly a resistance force stronger than that of the second resistance mode may be output.

In the second resistance mode, the processor <NUM> may control the motor driver circuit <NUM> based on a control signal having a duty ratio, which will be described in detail with reference to <FIG> below. The control signal may be a pulse width modulation (PWM) signal in which a high value and a low value are repeated. If a single period of the PWM signal is denoted by T and if an amount of time during which a high value is maintained in a single period is denoted by tH, the duty ratio may be denoted by tH/T. A control state of the motor driver circuit <NUM> may be switched between a first control state and a second control state according to a duty ratio of a PWM signal provided to the motor driver circuit <NUM>. In the first control state, terminals (e.g., a positive (+) terminal and a negative (-) terminal) of the motor <NUM> may be in an equipotential state. Here, the equipotential state may indicate that a potential (or voltage) of the + terminal and a potential (or voltage) of the - terminal in the motor <NUM> are equal to each other. In the second control state, the terminals of the motor <NUM> may be electrically opened. In the second resistance mode, when a user moves, the motor <NUM> may be rotated by a movement of the user, and an electromotive force may be generated in the motor <NUM> by the rotation of the motor <NUM>. However, in the second resistance mode, a rotation resistance for offsetting an electromotive force may be generated in the motor <NUM>. The above rotation resistance may be provided as a resistance force to a user. In other words, in the second resistance mode, the motor <NUM> may generate a resistance force to be provided to the user, due to the rotation resistance. In the second resistance mode, the motor <NUM> may output the resistance force even though power is not received from the battery <NUM>.

The motor driver circuit <NUM> may control an operation of the motor <NUM> under the control of the processor <NUM>. For example, the motor driver circuit <NUM> may form an electrical path so that power may be supplied from the battery <NUM> to the motor <NUM> under the control of the processor <NUM>. In addition, the motor driver circuit <NUM> may block an electrical connection between the battery <NUM> and the motor <NUM> under the control of the processor <NUM>. An example of the motor driver circuit <NUM> is shown in <FIG>. The motor driver circuit <NUM> illustrated in <FIG> may be an H-bridge circuit and include a plurality of switches <NUM> through <NUM>. When a first switch <NUM> and a fourth switch <NUM> are turned on and a second switch <NUM> and a third switch <NUM> are turned off under the control of the processor <NUM>, power may be supplied from the battery <NUM> to the motor <NUM>. When the first switch <NUM> and the second switch <NUM> are turned off under the control of the processor <NUM>, the electrical connection between the battery <NUM> and the motor <NUM> may be blocked.

The battery <NUM> may supply power to components of the wearable device <NUM>, for example, the sensor <NUM> and the processor <NUM>. Thick arrows shown in <FIG> and <FIG> indicate that the battery <NUM> supplies power to components of the wearable devices <NUM> and <NUM>-<NUM>. For example, a circuit (e.g., a power management integrated circuit (PMIC)) configured to convert power of the battery <NUM> to match an operating voltage of each of the components of the wearable device <NUM> and provide the power to the components of the wearable device <NUM> may be provided. In addition, the battery <NUM> may or may not supply power to the motor <NUM> based on the operation mode of the wearable device <NUM>. In other words, the battery <NUM> may supply power to the motor <NUM> in the first resistance mode, and may not supply power to the motor <NUM> in the second resistance mode. Accordingly, less power may be consumed in the battery <NUM> in the second resistance mode, and thus an available time for using the wearable device <NUM> may increase.

When a user is moving while wearing the wearable device <NUM> or <NUM>-<NUM> in the second resistance mode, the processor <NUM> may obtain a joint angle of the user using the sensor <NUM>. The processor <NUM> may increase the duty ratio when a difference between a reference angle and the obtained joint angle increases, in a state in which the difference between the reference angle and the obtained joint angle is greater than or equal to a set value. The processor <NUM> may provide a control signal of the increased duty ratio to the motor driver circuit <NUM> to control operations of switches included in the motor driver circuit <NUM>. When the difference between the reference angle and the joint angle increases due to an increase in a movement of the user, the motor <NUM> may output a resistance force with a higher intensity corresponding to the increased movement. This will be described below with reference to <FIG>.

According to implementation, the wearable device <NUM> or <NUM>-<NUM> may provide a support force to a user. When the difference between the reference angle and the joint angle increases in a negative direction, in a state in which the difference between the reference angle and the joint angle is less than or equal to the set value, the processor <NUM> may increase the duty ratio. The processor <NUM> may control the motor driver circuit <NUM> based on a control signal of the increased duty ratio. The difference between the reference angle and the joint angle may increase in the negative direction due to an increase in the movement of the user, and accordingly the motor <NUM> may output a support force with a higher intensity corresponding to the increased movement. This will be described below with reference to <FIG> and <FIG>.

The memory <NUM> may store software and data required for an operation of the wearable device <NUM> or <NUM>-<NUM>. The memory <NUM> may include, but is not limited to, for example, a nonvolatile memory, a volatile memory, a flash memory, and the like. The memory <NUM> may store resistance force generation setting information indicating a difference between the reference angle and each of joint angles and a corresponding relationship between respective duty ratios, which will be described below.

The input interface <NUM> may receive an input to control the wearable device <NUM> or <NUM>-<NUM> from a user. The input interface <NUM> may include, but is not limited to, for example, a physical button, a keypad, a jog wheel, a microphone, and the like.

Although not shown in <FIG>, the wearable device <NUM> or <NUM>-<NUM> may further include a display and a communication circuit.

The display may display state information of the wearable device <NUM> or <NUM>-<NUM>. For example, the display may display information on a charging capacity of the battery <NUM> and a resistance mode in which the wearable device <NUM> or <NUM>-<NUM> operates. In addition, the display may display information for controlling the operation of the wearable device <NUM> or <NUM>-<NUM>. For example, the display may display a user interface (UI) for receiving an input to select the first resistance mode or the second resistance mode from a user. The processor <NUM> may allow the wearable device <NUM> to operate in the first resistance mode when the user selects the first resistance mode through the UI, and allow the wearable device <NUM> to operate in the second resistance mode when the user selects the second resistance mode through the UI.

The communication circuit may include various communication circuits such as a short-range wireless communication circuit, a wireless local area network (LAN) communication circuit, a mobile communication circuit, and the like. The short-range wireless communication circuit may communicate with an electronic device (e.g., a mobile phone, a smartwatch, a tablet personal computer (PC), etc.) arranged in a short distance according to a short-range wireless communication scheme (e.g., near field communication (NFC), Bluetooth, ZigBee, etc.). The wireless LAN communication circuit may communicate with a server by accessing a network according to a wireless LAN communication scheme (e.g., wireless fidelity (Wi-Fi), etc.). The mobile communication circuit may communicate with a server by accessing a mobile communication network according to a mobile communication scheme (e.g., <NUM>, <NUM>, <NUM>, etc.).

Referring to <FIG>, the wearable device <NUM> may communicate with an electronic device <NUM>. For example, the electronic device <NUM> may be an electronic device associated with a user of the wearable device <NUM>. For example, a user wearing the wearable device <NUM> may exercise together with a trainer. In this example, the electronic device <NUM> may correspond to an electronic device associated with the trainer.

The wearable device <NUM> may communicate with the electronic device <NUM> based on the short-range wireless communication scheme. According to implementation, the wearable device <NUM> and the electronic device <NUM> may communicate with each other via a server using the short-range wireless communication scheme or the mobile communication scheme.

The electronic device <NUM> may display a UI for controlling an operation of the wearable device <NUM> on a display <NUM>-<NUM>. The UI may be, for example, a first soft key for allowing the wearable device <NUM> to operate in the first resistance mode, a second soft key for allowing the wearable device <NUM> to operate in the second resistance mode, a third soft key for changing a set value, and the like.

The user (or the trainer) may input a control command to control an operation of the wearable device <NUM> through the UI on the display <NUM>-<NUM> of the electronic device <NUM>, and the electronic device <NUM> may transmit the control command to the wearable device <NUM>. The wearable device <NUM> may operate according to the received control command, and transmit a control result to the electronic device <NUM>. The electronic device <NUM> may display a control completion message on the display <NUM>-<NUM> of the electronic device <NUM>.

For example, the user (or the trainer) may input a control command to control the wearable device <NUM> to operate in the first resistance mode by selecting the above-described first soft key, and the electronic device <NUM> may transmit the control command to the wearable device <NUM>. The wearable device <NUM> may operate in the first resistance mode according to the received control command, and may transmit a control result indicating that the wearable device <NUM> is operating in the first resistance mode to the electronic device <NUM>. The electronic device <NUM> may display a message indicating that the wearable device <NUM> is operating in the first resistance mode on the display <NUM>-<NUM>.

<FIG> are diagrams illustrating a first resistance mode of a wearable device according to an example embodiment.

The wearable device <NUM> may operate in the first resistance mode. In an example, a user may select the first resistance mode as the operation mode of the wearable device <NUM> through the input interface <NUM> of the wearable device <NUM> or the UI on the display of the wearable device <NUM>, so that the wearable device <NUM> may operate in the first resistance mode. In another example, the wearable device <NUM> may receive a control command to operate in the first resistance mode from the electronic device <NUM> and may operate in the first resistance mode according to the received control command. According to implementation, the first resistance mode may be a basic resistance mode of the wearable device <NUM>.

Referring to <FIG>, in the first resistance mode, the processor <NUM> may control the motor driver circuit <NUM> such that power may be supplied from the battery <NUM> to the motor <NUM>. In an example, in an example shown in <FIG>, the processor <NUM> may apply an ON signal <NUM> to the first switch <NUM> and apply an ON signal <NUM> to the fourth switch <NUM>. The processor <NUM> may independently output the ON signals <NUM> and <NUM>, as described above, however, this is merely an example. In another example, the processor <NUM> may output an ON signal, the output ON signal may be split by a separate circuit, and signals obtained by splitting the ON signal may be applied to the first switch <NUM> and the fourth switch <NUM>, respectively. The first switch <NUM> and the fourth switch <NUM> may be turned on by a control signal output from the processor <NUM>. Since an ON signal is not applied to each of the second switch <NUM> and the third switch <NUM>, the second switch <NUM> and the third switch <NUM> may be turned off. According to implementation, the processor <NUM> may apply an OFF signal to the second switch <NUM> and the third switch <NUM>, to turn off the second switch <NUM> and the third switch <NUM>. The motor <NUM> may be rotated in a forward direction in response to power being supplied from the battery <NUM>, to output a resistance force. Here, the forward direction may indicate that the motor <NUM> rotates in a clockwise direction.

The motor <NUM> may rotate in a backward direction in addition to the forward direction, to output a resistance force. The backward direction may indicate that the motor <NUM> rotates in a counterclockwise direction. In an example shown in <FIG>, the processor <NUM> may apply an ON signal <NUM> to the second switch <NUM> and apply an ON signal <NUM> to the third switch <NUM>. The processor <NUM> may independently output the ON signals <NUM> and <NUM>, as described above, however, this is merely an example. In another example, the processor <NUM> may output an ON signal, the output ON signal may be split by a separate circuit, and signals obtained by splitting the ON signal may be applied to the second switch <NUM> and the third switch <NUM>, respectively. The second switch <NUM> and the third switch <NUM> may be turned on under the control of the processor <NUM>. Since an ON signal is not applied to each of the first switch <NUM> and the fourth switch <NUM>, the first switch <NUM> and the fourth switch <NUM> may be turned off. According to implementation, the processor <NUM> may apply an OFF signal to the first switch <NUM> and the fourth switch <NUM>, to turn off the first switch <NUM> and the fourth switch <NUM>. The motor <NUM> may be rotated in the backward direction in response to power being supplied from the battery <NUM>, to output a resistance force.

In the first resistance mode, the motor <NUM> may output a resistance force by receiving power from the battery <NUM>, and thus a resistance force greater than that in the second resistance mode may be output.

<FIG> and <FIG> are diagrams illustrating a second resistance mode of a wearable device according to an example embodiment.

The wearable device <NUM> may operate in the second resistance mode. In an example, a user may select the second resistance mode as the operation mode of the wearable device <NUM> through the input interface <NUM> of the wearable device <NUM> or the UI on the display of the wearable device <NUM>, so that the wearable device <NUM> may operate in the second resistance mode. In another example, the wearable device <NUM> may receive a control command to operate in the second resistance mode from the electronic device <NUM> and may operate in the second resistance mode according to the received control command. In another example, when the charging capacity of the battery <NUM> is less than a predetermined criterion, the processor <NUM> may perform switching from the first resistance mode to the second resistance mode to minimize power use of the battery <NUM>. According to implementation, the second resistance mode may be a basic mode of the wearable device <NUM>.

Referring to <FIG>, in the second resistance mode, the processor <NUM> may control the control state of the motor driver circuit <NUM> to be switched between the first control state and the second control state. The second resistance mode will be described in detail with reference to <FIG>.

Referring to <FIG>, the processor <NUM> may turn off the first switch <NUM> and the second switch <NUM> to block the electrical connection between the battery <NUM> and the motor <NUM>. In the second resistance mode, the first switch <NUM> and the second switch <NUM> may remain in a state of being turned off.

The processor <NUM> may apply a control signal <NUM> to the third switch <NUM> and apply a control signal <NUM> to the fourth switch <NUM>, such that the control state of the motor driver circuit <NUM> may be switched between the first control state and the second control state. The control signals <NUM> and <NUM> may have a duty ratio in a form of a PWM signal in which a high value and a low value are repeated. As described above, the duty ratio may be tH/T when a single period is denoted by T and an amount of time during which a high value is maintained in a single period is denoted by tH. The processor <NUM> may independently output the control signals <NUM> and <NUM>, as described above, however, this is merely an example. In another example, the processor <NUM> may output a single control signal, the output control signal may be split by a separate circuit, and signals obtained by splitting the control signal may be applied to the third switch <NUM> and the fourth switch <NUM>, respectively.

When the control signals <NUM> and <NUM> are high values, the + terminal and the - terminal of the motor <NUM> may be connected to each other to be in the equipotential state. In other words, in the first control state, the + terminal and the - terminal of the motor <NUM> may be electrically connected to each other to have the same potential (or voltage).

In the first control state, the motor <NUM> may form a closed loop with the ground without an electrical connection with the battery <NUM>. Thus, the first control state may also be referred to as a closed loop state of the motor <NUM> free of the electrical connection with the battery <NUM>.

When a user moves in the first control state, the motor <NUM> around a joint of the user may rotate by a movement of the joint of the user. By such a rotation, an electromotive force (or a potential difference) may be generated in the motor <NUM>. Since the terminals of the motor <NUM> in the first control state are in the equipotential state, a rotation resistance may be generated in the motor <NUM> to reduce the generated electromotive force. The above rotation resistance may be provided as a resistance force to the user.

When the control signals <NUM> and <NUM> are low values, the + terminal and the - terminal of the motor <NUM> may be electrically opened. Since there is no electrical connection to the motor <NUM> in the second control state, the second control state may also be referred to as an open loop state of the motor <NUM>.

When the user moves in the second control state, the motor <NUM> may be rotated by the movement of the user. Since the + terminal and the - terminal of the motor <NUM> are electrically opened in the second control state, the above-described electromotive force may not be generated in the motor <NUM> and a resistance force may not be output.

Since the high values and the low values of the control signals <NUM> and <NUM> are repeated, the control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state.

The processor <NUM> may adjust a magnitude of the resistance force by controlling a duty ratio of each of the control signals <NUM> and <NUM>. When a time for which a high value is maintained increases in a period of each of the control signals <NUM> and <NUM>, a ratio of the motor <NUM> operating in the first control state in a period of each of control signals <NUM> and <NUM> may increase compared to a ratio of the motor <NUM> operating in the second control state in a period of each of control signals <NUM> and <NUM>. Thus, an intensity of the resistance force to be output to the user may increase.

In the second resistance mode, the wearable device <NUM> may output a resistance force without a power supply from the battery <NUM> to the motor <NUM>, and thus less power of the battery <NUM> may be consumed and an available time for using the wearable device <NUM> may increase. In addition, when the power of the battery <NUM> is supplied to the motor <NUM>, the motor <NUM> may malfunction. However, since in the second resistance mode, the power of the battery <NUM> is not supplied to the motor <NUM>, a potential malfunction of the motor <NUM> may be prevented and a safety of the wearable device <NUM> may be further enhanced.

<FIG> are diagrams illustrating examples of operations of a wearable device in the second resistance mode according to an example embodiment.

In an example shown in <FIG>, it is assumed that a user wears the wearable device <NUM>-<NUM> described with reference to <FIG> on lower extremities and performs an exercise of repeating abduction of lifting a first leg and adduction of lowering the first leg. The motor <NUM> may be disposed such that a resistance force may be output to each of the abduction and the adduction. The exercise of <FIG> is to obtain an effect of strength training, because a resistance force output from the wearable device <NUM>-<NUM> increases if the user lifts the first leg at an angle greater than or equal to a reference angle. To generate a resistance force suitable for the purpose of exercise, resistance force generation setting information (e.g., Table <NUM> shown below, or a relational expression corresponding to a graph shown in <FIG>) may be stored in the memory <NUM> of the wearable device <NUM>-<NUM>. Alternatively, the wearable device <NUM>-<NUM> may receive resistance force generation setting information from an external device (e.g., a server or the electronic device <NUM>-<NUM>) through a communication module, and may store the resistance force generation setting information in the memory <NUM>.

Table <NUM> and the relational expression corresponding to the graph shown in <FIG> are merely examples for explaining the resistance force generation setting information for the exercise of <FIG>, and the resistance force generation setting information for the exercise of <FIG> is not limited to Table <NUM> and the relational expression corresponding to the graph shown in <FIG>.

Before the user exercises, the motor driver circuit <NUM> may be in the second control state.

When the user exercises, the processor <NUM> may obtain a first hip joint angle -a1 of the user, using the sensor <NUM>. For example, the sensor <NUM>, which is an encoder, may transmit a first bit value corresponding to a first position of a shaft to the processor <NUM>, before the user moves. When the user moves, the shaft of the encoder may rotate, and the sensor <NUM> may transmit a second bit value corresponding to a second position changed by the rotation of the shaft to the processor <NUM>. The processor <NUM> may obtain a difference between an angle corresponding to the second bit value and an angle corresponding to the first bit value as the first hip joint angle -a1. According to implementation, the sensor <NUM> may calculate a difference between an angle corresponding to the second position and an angle corresponding to the first position, and may transmit the calculated difference to the processor <NUM>. The processor <NUM> may receive the difference between the angle corresponding to the second position and the angle corresponding to the first position from the sensor <NUM> to obtain the first hip joint angle -a1. In the example shown in <FIG>, the first hip joint angle obtained when the user lifts the first leg may be a negative number. This is merely an example, and the first hip joint angle obtained when the user lifts the first leg may be a positive number.

The processor <NUM> may calculate a difference "-b1 + a1" between the reference angle -b1 and the first hip joint angle -a1.

If "-b <NUM> + a1" is less than a set value of "<NUM>" based on the resistance force generation setting information, the processor <NUM> may maintain the second control state of the motor <NUM>.

If "-b1 + a1" is <NUM>° exceeding the set value of "<NUM>", the processor <NUM> may check a duty ratio of "<NUM>" corresponding to <NUM>° based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>". By the above repeatedly switching, the motor <NUM> may output a resistance force.

When "-b1 + a1" increases as the user lifts the first leg higher, the processor <NUM> may increase (or change) the duty ratio based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the increased (or changed) duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. Due to an increase in the duty ratio, the motor <NUM> may be in the first control state for a relatively long time within one period, to output a resistance force with a higher intensity.

For example, when "-b1 + a1" becomes <NUM>°, the processor <NUM> may check a duty ratio of "<NUM>" corresponding to <NUM>° based on the resistance force generation setting information, and may apply the control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>". By the above repeatedly switching, the motor <NUM> may output a resistance force. The motor driver circuit <NUM> may be in the first control state for a relatively long time within one period when the duty ratio is "<NUM>", in comparison to when the duty ratio is "<NUM>". Thus, the motor <NUM> may output a resistance force with a higher intensity when the duty ratio is "<NUM>", in comparison to when the duty ratio is "<NUM>".

If "-b <NUM> + a1" is greater than or equal to θmotion1, the processor <NUM> may apply control signals <NUM> and <NUM> with a maximum duty ratio (e.g., "<NUM>") to the third switch <NUM> and the fourth switch <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second state according to the maximum duty ratio, and accordingly the motor <NUM> may output a resistance force with a maximum intensity.

For example, when the user lowers the first leg in a situation in which the resistance force is output to the first leg, "-b <NUM> + a1" may decrease. In this example, the processor <NUM> may reduce the duty ratio based on the resistance force generation setting information and apply control signals <NUM> and <NUM> with the reduced duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. If the user lowers the first leg, the duty ratio may decrease. Thus, the motor <NUM> may output a resistance force with a relatively low intensity.

If "-b1 + a1" is less than the set value of "<NUM>", the processor <NUM> may not apply any signal to the third switch <NUM> and the fourth switch <NUM> such that the third switch <NUM> and the fourth switch <NUM> may be turned off. Accordingly, the motor driver circuit <NUM> may be in the second control state, and a resistance force may not be output from the motor <NUM>.

Unlike the examples described with reference to <FIG> and <FIG>, a first hip joint angle a1 of the user may be a positive number.

The processor <NUM> may calculate a difference "b1 - a1" between a reference angle b1 and the first hip joint angle a1.

When "b1 - a1" exceeds the set value of "<NUM>", the processor <NUM> may maintain the second control state of the motor driver circuit <NUM> based on resistance force generation setting information (e.g., Table <NUM> shown below, or a relational expression corresponding to a graph shown in <FIG>) stored in the memory <NUM>.

Table <NUM> and the relational expression corresponding to the graph shown in <FIG> are merely examples for explaining the resistance force generation setting information for the exercise of <FIG>, and the resistance force generation setting information is not limited to Table <NUM> and the relational expression corresponding to the graph shown in <FIG>.

If "b1 - a1" is -<NUM>° that is less than the set value of "<NUM>", the processor <NUM> may check a duty ratio of "<NUM>" corresponding to -<NUM>° based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a resistance force.

When "b1 - a1" increases in a negative direction as the user lifts the first leg higher, the processor <NUM> may increase a duty ratio based on the resistance force generation setting information and may apply control signals <NUM> and <NUM> with the increased duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively.

If "b1 - a1" is less than or equal to -θmotion1, the processor <NUM> may apply control signals <NUM> and <NUM> with a maximum duty ratio (e.g., "<NUM>") to the third switch <NUM> and the fourth switch <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second state according to the maximum duty ratio, and accordingly the motor <NUM> may output a resistance force with a maximum intensity.

When "b1 - a1" exceeds the set value of "<NUM>", the processor <NUM> may not apply any signal to the third switch <NUM> and the fourth switch <NUM> so that the third switch <NUM> and the fourth switch <NUM> may be turned off. Accordingly, the motor driver circuit <NUM> may be in the second control state, and a resistance force may not be output from the motor <NUM>.

In an example embodiment, the processor <NUM> may allow a resistance force to be output based on the first hip joint angle -a1. More specifically, the memory <NUM> may store resistance force generation setting information (e.g., Table <NUM> shown below, or a relational expression corresponding to Table <NUM>) for generating a resistance force according to the first hip joint angle - a1 increased to be greater than or equal to a predetermined angle.

When the first hip joint angle -a1 is greater than -<NUM>° (for example, when the first hip joint angle -a1 is -<NUM>°) even though the user lifts the first leg, the processor <NUM> may not apply any signal to each of the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM> such that a resistance force may not be generated based on the resistance force generation setting information.

When the first hip joint angle -a1 is -<NUM>°, the processor <NUM> may check a duty ratio of "<NUM>" corresponding to -<NUM>° based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a resistance force.

When the first hip joint angle -a1 increases in the negative direction, the processor <NUM> may increase the duty ratio based on the resistance force generation setting information and may apply control signals <NUM> and <NUM> with the increased duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. Accordingly, the duty ratio may increase, as the user lifts the first leg higher. Thus, the motor <NUM> may output a resistance force with a higher intensity.

When the first hip joint angle -a1 is less than or equal to -θmotion1_1, the processor <NUM> may apply control signals <NUM> and <NUM> with a maximum duty ratio (e.g., "<NUM>") to the third switch <NUM> and the fourth switch <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the maximum duty ratio, and accordingly the motor <NUM> may output a resistance force with a maximum intensity.

When the user lowers the first leg in a situation in which the resistance force is output to the first leg, the first hip joint angle -a1 may decrease. In this example, the processor <NUM> may reduce the duty ratio based on the resistance force generation setting information and apply control signals <NUM> and <NUM> with the reduced duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. If the user lowers the first leg, the duty ratio may decrease. Thus, the motor <NUM> may output a resistance force with a lower intensity.

The first hip joint angle a1 may be a positive number. The memory <NUM> may store resistance force generation setting information (e.g., Table <NUM> shown below, or a relational expression corresponding to Table <NUM>) for generating a resistance force according to the first hip joint angle a1 increased to be greater than or equal to a predetermined angle.

When the first hip joint angle a1 is less than <NUM>° even though the user lifts the first leg, the processor <NUM> may not apply any signal to each of the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM> such that a resistance force may not be generated based on the resistance force generation setting information.

When the first hip joint angle a1 is <NUM>°, the processor <NUM> may apply control signals <NUM> and <NUM> with a duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively, based on the resistance force generation setting information.

When the first hip joint angle a1 increases, the processor <NUM> may increase the duty ratio based on the resistance force generation setting information and may apply control signals <NUM> and <NUM> with the increased duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. Accordingly, the duty ratio may increase, if the user lifts the first leg. Thus, the motor <NUM> may output a resistance force with a higher intensity.

When the first hip joint angle a1 is greater than or equal to θmotion1_1, the processor <NUM> may apply control signals <NUM> and <NUM> with a maximum duty ratio (e.g., "<NUM>") to the third switch <NUM> and the fourth switch <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the maximum duty ratio, and accordingly the motor <NUM> may output a resistance force with a maximum intensity.

When the user lowers the first leg in a situation in which the resistance force is output to the first leg, the first hip joint angle a1 may decrease. In this example, the processor <NUM> may reduce the duty ratio based on the resistance force generation setting information and apply control signals <NUM> and <NUM> with the reduced duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. If the user lowers the first leg, the duty ratio may decrease. Thus, the motor <NUM> may output a resistance force with a lower intensity.

In an example shown in <FIG>, it is assumed that a user wearing the wearable device <NUM>-<NUM> described with reference to <FIG> walks. Each of the motors <NUM> and <NUM>-<NUM> may be disposed around each hip joint, as described above with reference to <FIG>. When a stride of the user is out of a predetermined range, the wearable device <NUM>-<NUM> may guide the user to walk correctly by outputting a resistance force. To generate a resistance force in a right leg, resistance force generation setting information (e.g., Tables <NUM> and <NUM> shown below, or a relational expression corresponding to a graph shown in <FIG>) may be stored in the memory <NUM>. Similarly, to generate a resistance force in a left leg, resistance force generation setting information (e.g., Tables <NUM> and <NUM> shown below, or a relational expression corresponding to a graph shown in <FIG>) may be stored in the memory <NUM>.

Tables <NUM> through <NUM> and the relational expressions corresponding to the graphs shown in <FIG> are merely examples for explaining the resistance force generation setting information for the exercise of <FIG>, and the resistance force generation setting information for the exercise of <FIG> is not limited to Tables <NUM> through <NUM> and the relational expressions corresponding to the graphs shown in <FIG>.

Since the wearable device <NUM>-<NUM> outputs a resistance force to the left leg in the same manner as that of outputting the resistance force to the right leg, a method by which the wearable device <NUM>-<NUM> outputs the resistance force to the right leg will be described below.

The motor driver circuit <NUM> near a right hip joint may be in the second control state, before the user walks.

The processor <NUM> may obtain the hip joint angle -Xright of the right leg, using the sensor <NUM>. In the example shown in <FIG>, a hip joint angle when a leg of the user is in front of a reference line may correspond to a negative number, and a hip joint angle when the leg of the user is behind the reference line may correspond to a positive number.

The processor <NUM> may calculate "-Y + Xright" between a negative reference angle -Y and the hip joint angle -Xright of the right leg.

When "-Y + Xright" is less than a positive set value d based on the resistance force generation setting information, the processor <NUM> may maintain the second control state of the motor <NUM>. According to implementation, the set value d may be "<NUM>.

When "-Y + Xright" is <NUM>°, the processor <NUM> may check a duty ratio of "<NUM>" corresponding to <NUM>° based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a resistance force.

When "-Y + Xright" increases as the user lifts the right leg higher by walking, the processor <NUM> may increase (or change) the duty ratio based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the increased (or changed) duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. Due to an increase in the duty ratio, the motor driver circuit <NUM> may be in the first control state for a relatively long time within one period, and accordingly a resistance force with a higher intensity may be output.

For example, when "-Y + Xright" is increased to <NUM>°, the processor <NUM> may check a duty ratio of "<NUM>" corresponding to <NUM>° based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a resistance force with a higher intensity. The motor driver circuit <NUM> may be in the first control state for a relatively long time within one period when the duty ratio is "<NUM>", in comparison to when the duty ratio is "<NUM>". Accordingly, the motor <NUM> may output a resistance force with a higher intensity when the duty ratio is "<NUM>", in comparison to when the duty ratio is "<NUM>".

When "-Y + Xright" is greater than or equal to θmotion2, the processor <NUM> may apply control signals <NUM> and <NUM> with a maximum duty ratio (e.g., "<NUM>") to the third switch <NUM> and the fourth switch <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the maximum duty ratio, and accordingly the motor <NUM> may output a resistance force with a maximum intensity.

In a situation in which the resistance force is output to the right leg, the right hip joint angle -Xright of the user may be reduced due to walking and "-Y + Xright" may be reduced. In this example, the processor <NUM> may reduce the duty ratio based on the resistance force generation setting information and apply control signals <NUM> and <NUM> with the reduced duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. When the right hip joint angle -Xright is reduced, the duty ratio may be reduced, and accordingly the motor <NUM> may output a resistance force with a relatively low intensity.

When "-Y + Xright" is less than the positive set value d, the processor <NUM> may not apply any signal to the third switch <NUM> and the fourth switch <NUM> such that the third switch <NUM> and the fourth switch <NUM> may be turned off. Accordingly, the motor driver circuit <NUM> may be in the second control state, and the resistance force may not be output from the motor <NUM>.

By walking, the right leg may be behind the reference line.

When a difference "Y - Xright" between the positive reference angle Y and the hip joint angle + Xright of the right leg is less than or equal to a negative set value -d and when "Y - Xright" is -<NUM>°, the processor <NUM> may check a duty ratio of "<NUM>" corresponding to -<NUM>° based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a resistance force.

When "Y - Xright" increases in the negative direction to -<NUM>°, the processor <NUM> may check a duty ratio of "<NUM>" corresponding to -<NUM>° based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a resistance force.

When "Y - Xright" is less than or equal to -θmotion2, the processor <NUM> may apply control signals <NUM> and <NUM> with a maximum duty ratio (e.g., "<NUM>") to the third switch <NUM> and the fourth switch <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the maximum duty ratio, and accordingly the motor <NUM> may output a resistance force with a maximum intensity.

The motor <NUM>-<NUM> may output a resistance force to the left leg in a similar manner that the motor <NUM> outputs the resistance force to the right leg. When a difference "-Y + X left" between a negative reference angle -Y and a left hip joint angle -Xleft is greater than or equal to "<NUM>" and less than "d", the motor <NUM>-<NUM> may not output a resistance force. When a duty ratio increases as "-Y + Xleft" increases from "d", the motor <NUM>-<NUM> may output a resistance force with a relatively high intensity to the left leg. When "-Y + Xi,ft" is greater than or equal to θmotion2, the motor <NUM>-<NUM> may output a resistance force with a maximum intensity to the left leg. Similarly, when a difference "Y - Xi,ft" between a positive reference angle Y and a left hip joint angle +Xleft is less than or equal to "<NUM>" and greater than or equal to "-d", the motor <NUM>-<NUM> may not output a resistance force. When the duty ratio increases as "Y - Xleft" decreases from "-d", the motor <NUM>-<NUM> may output a resistance force with a relatively high intensity to the left leg. When "Y - Xleft" is less than or equal to -θmotion2, the motor <NUM>-<NUM> may output the resistance force with the maximum intensity to the left leg.

In the example described with reference to <FIG>, the wearable device <NUM>-<NUM> may output the resistance force to the user, when a difference between a reference angle and a hip joint angle of the right leg is out of a range of "-d" to "d", and when a difference between the reference angle and a hip joint angle of the left leg is out of the range of "-d" to "d". Accordingly, the wearable device <NUM>-<NUM> may guide the user to walk so that both hip joint angles may rotate within a predetermined range. In addition, the wearable device <NUM>-<NUM> may guide the user to walk such that a stride of the right leg and a stride of the left leg may substantially be the same.

In an example embodiment, the processor <NUM> may allow a resistance force to be output based on the right hip joint angle and the left hip joint angle. More specifically, the memory <NUM> may store resistance force generation setting information (e.g., Tables <NUM> and <NUM> shown below, or relational expressions corresponding to Tables <NUM> and <NUM>) for generating a resistance force according to a right hip joint angle increased to be greater than or equal to a predetermined angle, and may store resistance force generation setting information (e.g., Tables <NUM> and <NUM> shown below, or relational expressions corresponding to Tables <NUM> and <NUM>) for generating a resistance force according to a left hip joint angle increased to be greater than or equal to a predetermined angle.

Before the user starts walking, the motor driver circuit <NUM> may be in the second control state.

When the user walks by rotating the right leg forward, the right hip joint angle -Xright may be increased. When the right hip joint angle -Xright is greater than -<NUM>° (for example, when the right hip joint angle -Xright is -<NUM>°) based on the resistance force generation setting information, the processor <NUM> may maintain the second control state of the motor driver circuit <NUM>.

When the right hip joint angle -Xright is -<NUM>°, the processor <NUM> may check a duty ratio of "<NUM>" corresponding to -<NUM>° based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a resistance force.

When the right hip joint angle -Xright increases in the negative direction, the processor <NUM> may increase the duty ratio based on the resistance force generation setting information and may apply control signals <NUM> and <NUM> with the increased duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. Due to an increase in the duty ratio, the motor <NUM> may output a resistance force with a higher intensity.

When the right hip joint angle -Xright is less than or equal to -θmotion2_1, the processor <NUM> may apply control signals <NUM> and <NUM> with a maximum duty ratio (e.g., "<NUM>") to the third switch <NUM> and the fourth switch <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the maximum duty ratio, and accordingly the motor <NUM> may output a resistance force with a maximum intensity.

In a situation in which the resistance force is output to the right leg, the right hip joint angle -Xright may be reduced due to walking. In this example, the processor <NUM> may reduce the duty ratio based on the resistance force generation setting information and apply control signals <NUM> and <NUM> with the reduced duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. When the right hip joint angle -Xright decreases, the duty ratio may decrease. Thus, the motor <NUM> may output a resistance force with a relatively low intensity.

When the right hip joint angle -Xright is greater than -<NUM>° (for example, when the right hip joint angle -Xright is -<NUM>°), the processor <NUM> may not apply any signal to the third switch <NUM> and the fourth switch <NUM> such that the third switch <NUM> and the fourth switch <NUM> may be turned off. Accordingly, the motor driver circuit <NUM> may be in the second control state, and the resistance force may not be output from the motor <NUM>.

When the hip joint angle Xright of the right leg is <NUM>°, the processor <NUM> may check a duty ratio of "<NUM>" corresponding to <NUM>° based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a resistance force.

When the right hip joint angle Xright increases, the processor <NUM> may increase the duty ratio based on the resistance force generation setting information and may apply control signals <NUM> and <NUM> with the increased duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. Due to an increase in the duty ratio, the motor <NUM> may output a resistance force with a higher intensity.

When the right hip joint angle Xright is greater than or equal to θmotion2_1, the processor <NUM> may apply control signals <NUM> and <NUM> with a maximum duty ratio (e.g., "<NUM>") to the third switch <NUM> and the fourth switch <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the maximum duty ratio, and accordingly the motor <NUM> may output a resistance force with a maximum intensity.

The motor <NUM>-<NUM> may output a resistance force to the left leg in a similar manner that the motor <NUM> outputs the resistance force to the right leg. When the left hip j oint angle -Xleft is less than "<NUM>" and greater than -<NUM>°, the motor <NUM>-<NUM> may not output a resistance force. When the left hip joint angle -Xleft increases in the negative direction from -<NUM>°, the duty ratio may increase, and accordingly the motor <NUM>-<NUM> may output a resistance force with a relatively high intensity to the left leg. When the left hip joint angle -Xleft is less than or equal to -θmotion2_1, the motor <NUM>-<NUM> may output a resistance force with a maximum intensity to the left leg. When the left hip joint angle Xleft is greater than "<NUM>" and less than <NUM>°, the motor <NUM>-<NUM> may not output a resistance force. When the left hip joint angle Xleft increases from <NUM>°, the duty ratio may increase, and accordingly the motor <NUM>-<NUM> may output a resistance force with a relatively high intensity to the left leg. When the left hip joint angle X left is greater than or equal to θmotion2_1, the motor <NUM>-<NUM> may output a resistance force with a maximum intensity to the left leg.

In an example shown in <FIG>, it is assumed that a user wearing the wearable device <NUM> described above with reference to <FIG> performs an exercise of lifting a first arm. The above exercise is to obtain an effect of strength training, because a resistance force output from the wearable device <NUM> increases if the user lifts the first arm higher. When the user lowers the lifted first arm, the wearable device <NUM> may not output a resistance force. In other words, the wearable device <NUM> may output a resistance force when a preset rotation direction and a rotation direction of a first shoulder joint angle match, and may not output the resistance force when the preset rotation direction and the rotation direction of the first shoulder joint angle do not match. Resistance force generation setting information (e.g., Table <NUM> shown below, or a relational expression corresponding to a graph shown in <FIG>) for generating a resistance force may be stored in a memory of the wearable device <NUM>.

Before the user starts exercising, the motor driver circuit <NUM> of the wearable device <NUM> may be in the second control state.

When the user exercises, the processor <NUM> may obtain the first shoulder joint angle -c using the sensor <NUM>. In the example shown in <FIG>, the first shoulder joint angle obtained when the user lifts the first arm may be a negative number.

The processor <NUM> may calculate a difference "-e + c" between the reference angle -e and the first shoulder joint angle -c.

When "-e + c" increases, the processor <NUM> may estimate or determine the rotation direction of the first shoulder joint to be a counterclockwise direction. When the preset rotation direction is the counterclockwise direction, the processor <NUM> may determine that the rotation direction of the first shoulder joint matches the preset rotation direction.

When the rotation direction of the first shoulder joint matches the preset direction and when "-e + c" is <NUM>°, the processor <NUM> may check a duty ratio of "<NUM>" corresponding to <NUM>° based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a resistance force.

When "-e + c" increases as the user lifts the first arm higher, the processor <NUM> may increase the duty ratio based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the increased duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. Due to an increase in the duty ratio, the motor driver circuit <NUM> may be in the first control state for a relatively long time within one period, and accordingly a resistance force with a higher intensity may be output.

For example, when "-e + c" becomes <NUM>°, the processor <NUM> may check a duty ratio of "<NUM>" corresponding to <NUM>° based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a resistance force. The motor driver circuit <NUM> may be in the first control state for a relatively long time within one period when the duty ratio is "<NUM>", in comparison to when the duty ratio is "<NUM>". Accordingly, the motor <NUM> may output a resistance force with a higher intensity when the duty ratio is "<NUM>", in comparison to when the duty ratio is "<NUM>".

When the user lowers the first arm, "-e + c" may be reduced. Here, the processor <NUM> may determine that the rotation direction of the first shoulder joint does not match the counterclockwise direction that is set in advance, and may not apply any signal to the third switch <NUM> and the fourth switch <NUM> such that the third switch <NUM> and the fourth switch <NUM> may be turned off. Accordingly, when the user lowers the first arm, the motor <NUM> may not output the resistance force.

In an example embodiment, the processor <NUM> may allow a resistance force to be output based on the first shoulder joint angle -c. More specifically, the memory <NUM> may store resistance force generation setting information (e.g., Table <NUM> shown below, or a relational expression corresponding to Table <NUM>) for generating a resistance force according to the first shoulder joint angle -c when the rotation direction of the first shoulder joint matches the preset rotation direction and when the first shoulder joint angle -c is greater than or equal to a predetermined angle.

When the first shoulder joint angle -c increases in the negative direction as the user lifts the first arm, the processor <NUM> may determine that the rotation direction of the first shoulder joint matches the counterclockwise direction that is set advance. Here, when the first shoulder joint angle -c corresponds to -<NUM>°, the processor <NUM> may check a duty ratio of "<NUM>" corresponding to - <NUM>° based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a resistance force.

When the first shoulder joint angle -c increases in the negative direction as the user lifts the first arm higher, the processor <NUM> may increase the duty ratio based on the resistance force generation setting information, and may apply control signals <NUM> and <NUM> with the increased duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. Due to an increase in the duty ratio, the motor <NUM> may output a resistance force with a higher intensity.

When the user lowers the first arm, the first shoulder j oint angle -c may be reduced. Here, the processor <NUM> may determine that the rotation direction of the first shoulder joint does not match the counterclockwise direction that is set in advance, and may not apply any signal to the third switch <NUM> and the fourth switch <NUM> such that the third switch <NUM> and the fourth switch <NUM> may be turned off. Accordingly, when the user lowers the first arm, the motor <NUM> may not output the resistance force.

<FIG> and <FIG> are diagrams illustrating an example in which a wearable device provides a support force to a user according to an example embodiment.

Referring to <FIG>, it is assumed that a user wears the wearable device <NUM>-<NUM> described above with reference to <FIG> and works with a first arm. If the first arm is lowered by an angle less than or equal to a reference angle, a support force output by the wearable device <NUM>-<NUM> may increase to assist the user in working. Support force generation setting information (e.g., Table <NUM> shown below, or a relational expression corresponding to a graph shown in <FIG>) for generating a support force may be stored in a memory of the wearable device <NUM>-<NUM>.

The processor <NUM> may obtain the first shoulder joint angle -a2 using the sensor <NUM>.

The processor <NUM> may calculate a difference "-b2 + a2" between the reference angle -b2 and the first shoulder joint angle -a2.

When the user lowers the first arm at an angle less than or equal to the reference angle - b2, the first shoulder joint angle -a2 may be reduced. When "-b2 + a2" is less than or equal to a set value of "<NUM>", the processor <NUM> may assist the user in working.

More specifically, when "-b2 + a2" is -<NUM>°, the processor <NUM> may check the duty ratio of "<NUM>" based on the support force generation setting information, and apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a support force. When "-b2 + a2" increases in the negative direction as the first arm is lowered further down, the processor <NUM> may increase the duty ratio based on the support force generation setting information, and may apply control signals <NUM> and <NUM> with the increased duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. Due to an increase in the duty ratio, the motor <NUM> may output a support force with a higher intensity.

In an example embodiment, the processor <NUM> may allow a support force to be output based on the first shoulder joint angle -a2. More specifically, the memory <NUM> may store support force generation setting information (e.g., Table <NUM> shown below, or a relational expression corresponding to Table <NUM>) for generating a support force according to the first shoulder joint angle -a2 increased to be greater than or equal to a predetermined angle.

When the user lowers the first arm while working with the first arm, the first shoulder joint angle -a2 may be reduced. When the first shoulder joint angle -a2 is reduced to be less than -<NUM>°, the processor <NUM> may assist the user in working. More specifically, when the first shoulder joint angle -a2 is -<NUM>°, the processor <NUM> may check a duty ratio of "<NUM>" based on the support force generation setting information, and apply control signals <NUM> and <NUM> with the duty ratio of "<NUM>" to the third switch <NUM> and the fourth switch <NUM>, respectively. The control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state according to the duty ratio of "<NUM>", and accordingly the motor <NUM> may output a support force. When the first shoulder joint angle -a2 decreases as the first arm is lowered further down, the processor <NUM> may increase the duty ratio based on the support force generation setting information, and may apply control signals <NUM> and <NUM> with the increased duty ratio to the third switch <NUM> and the fourth switch <NUM>, respectively. Due to an increase in the duty ratio, the motor <NUM> may output a support force with a higher intensity.

<FIG> are diagrams illustrating an adjustment of an intensity of a resistance force in a second resistance mode of a wearable device according to an example embodiment.

A user may request the wearable devices <NUM> and <NUM>-<NUM> described with reference to <FIG> and <FIG> to adjust the intensity through the input interface <NUM> so that a resistance force with a higher intensity or a lower intensity may be output. In an example, the user may utter "increase (or decrease) the intensity by one level" and a microphone of the wearable device <NUM>, <NUM>-<NUM> may receive voice uttered by the user. In another example, resistance force intensity values of multiple levels may be displayed on a display of the wearable device <NUM>, <NUM>-<NUM>, and the user may select one of the displayed resistance force intensity values.

In <FIG>, in response to a user input to increase the intensity of the resistance force by one level, the processor <NUM> may generate a second graph <NUM> by increasing a slope of a first graph <NUM>. The processor <NUM> may control the motor driver circuit <NUM> based on the second graph <NUM>. For the same difference between a reference angle and a first joint angle, a resistance force with a higher intensity may be output in the second graph <NUM> in comparison to the first graph <NUM>.

In response to a user input to further increase the intensity of the resistance force by one level in a situation in which the resistance force is output according to the second graph <NUM>, the processor <NUM> may generate a third graph <NUM> by increasing a slope of the second graph <NUM> and may control the motor driver circuit <NUM> so that the resistance force may be output according to the third graph <NUM>. For the same difference between the reference angle and the first joint angle, a resistance force with a higher intensity may be output in the third graph <NUM> in comparison to the second graph <NUM>.

In response to a user input to increase the intensity of the resistance force to the maximum level in a situation in which the resistance force is output according to the third graph <NUM>, the processor <NUM> may generate a fourth graph <NUM> by increasing a slope of the third graph <NUM> and may control the motor driver circuit <NUM> so that the resistance force may be output according to the fourth graph <NUM>. In the fourth graph <NUM>, if the difference between the reference angle and the first joint angle corresponds to a set value of "<NUM>," a resistance force with a maximum intensity may be output.

In an example embodiment, in response to a user input to increase the intensity of the resistance force, the processor <NUM> may increase the intensity of the resistance force by changing to a nonlinear graph.

In an example shown in <FIG>, in response to a user input to increase the intensity of the resistance force by one level in a situation in which the resistance force is output according to a first graph <NUM>, the processor <NUM> may change the first graph <NUM> to a first nonlinear graph <NUM> and may control the motor driver circuit <NUM> so that the resistance force may be output according to the first nonlinear graph <NUM>. For the same difference between the reference angle and the first joint angle, a resistance force with a higher intensity may be output in the first nonlinear graph <NUM> in comparison to the first graph <NUM>.

In response to a user input to further increase the intensity of the resistance force by one level in a situation in which the resistance force is output according to the first nonlinear graph <NUM>, the processor <NUM> may change the first nonlinear graph <NUM> to a second nonlinear graph <NUM> and may control the motor driver circuit <NUM> so that the resistance force may be output according to the second nonlinear graph <NUM>. For the same difference between the reference angle and the first joint angle, a resistance force with a higher intensity may be output in the second nonlinear graph <NUM> in comparison to the first nonlinear graph <NUM>.

In response to a user input to increase the intensity of the resistance force to the maximum level in a situation in which the resistance force is output according to the second nonlinear graph <NUM>, the processor <NUM> may change the second nonlinear graph <NUM> to a fourth graph <NUM> and may control the motor driver circuit <NUM> so that the resistance force may be output according to the fourth graph <NUM>.

Similarly to the description provided with reference to <FIG>, the processor <NUM> may change the graphs shown in <FIG>, <FIG>, <FIG>, and <FIG>. More specifically, if a user input to increase the intensity of the resistance force in the exercise of <FIG> is received from a user, the processor <NUM> may change the graph of <FIG>, similarly to the description provided with reference to <FIG>. If a user input to increase the intensity of the resistance force in the exercise of <FIG> is received from a user, the processor <NUM> may change the graphs of <FIG>, similarly to the description provided with reference to <FIG>. If a user input to increase the intensity of the resistance force in the exercise of <FIG> is received from a user, the processor <NUM> may change the graph of <FIG>, similarly to the description provided with reference to <FIG>. If a user input to increase the intensity of the support force in the work of <FIG> is received from a user, the processor <NUM> may change the graph of <FIG>, similarly to the description provided with reference to <FIG>.

<FIG> is a diagram illustrating a change in a reference angle in a second resistance mode of a wearable device according to an example embodiment.

In <FIG>, it is assumed that a user performs the exercise described with reference to <FIG>. In an example, when the user lifts his or her leg by a relatively small angle, a relatively narrow reference angle may be input through the input interface <NUM> such that a resistance force may be output. In another example, when the user lifts the leg by a relatively large angle, a relatively wide reference angle may be input through the input interface <NUM> so that a resistance force may be output. The processor <NUM> may change the reference angle to a reference angle input by the user.

For example, the reference angle before the change may be -<NUM>°. In this example, when a hip joint angle of the leg is -<NUM>°, the processor <NUM> may apply the control signals <NUM> and <NUM> with the duty ratio of "<NUM>" in Table <NUM> described above to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The motor <NUM> may output a resistance force with an intensity corresponding to the duty ratio of "<NUM>. " In other words, when the user lifts the leg by <NUM>° in a state in which the reference angle is -<NUM>°, the resistance force with the intensity corresponding to the duty ratio of "<NUM>" may be provided to the user.

The user may input the reference angle changed to -<NUM>° through the input interface <NUM>, and the processor <NUM> may change the reference angle from -<NUM>° to -<NUM>°.

When the hip joint angle of the leg is -<NUM>°, the processor <NUM> may apply the control signals <NUM> and <NUM> with the duty ratio of "<NUM>" in Table <NUM> described above to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. The motor <NUM> may output a resistance force with an intensity corresponding to the duty ratio of "<NUM>. " In other words, when the user lifts the leg by <NUM>° in a situation in which the reference angle is changed to -<NUM>°, the resistance force with the intensity corresponding to the duty ratio of "<NUM>" may be provided to the user. Thus, the resistance force may be provided to the user when the user lifts the leg less than when the reference angle is -<NUM>°.

When the hip joint angle of the leg is -<NUM>°, the processor <NUM> may apply the control signals <NUM> and <NUM> with the duty ratio of "<NUM>" in Table <NUM> described above to the third switch <NUM> and the fourth switch <NUM> of the motor driver circuit <NUM>, respectively. When the user lifts the leg by <NUM>°, the resistance force with the intensity corresponding to the duty ratio of "<NUM>" may be provided to the user. In other words, when the user lifts the leg further up in comparison to when the reference angle is -<NUM>°, the resistance force may be provided.

The processor <NUM> may change the reference angle, so that the user may be provided with the resistance force in various motion angle ranges.

Similarly to the description provided with reference to <FIG>, the processor <NUM> may change the reference angle described with reference to <FIG>.

<FIG> through 14D are diagrams illustrating a change in a set value in a second resistance mode of a wearable device according to an example embodiment.

Referring to <FIG>, a UI for changing a set value may be displayed on a display <NUM> of the wearable device <NUM>, <NUM>-<NUM>. The UI may include a soft key <NUM>-<NUM> for increasing the set value, and a soft key <NUM>-<NUM> for reducing the set value. In <FIG>, the processor <NUM> may increase the set value when a user presses the soft key <NUM>-<NUM>, and may reduce the set value when the user presses the soft key <NUM>-<NUM>.

Referring to <FIG>, various set values may be displayed on the display <NUM> of the wearable device <NUM>, <NUM>-<NUM> in the form of a table. The user may move a screen using the scroll bar <NUM>. The user may select one of the set values displayed on the display <NUM>.

Referring to <FIG>, the electronic device <NUM>-<NUM> may expose a UI for changing a set value on the display <NUM>-<NUM>. Such a UI may include the softkeys <NUM>-<NUM> and <NUM>-<NUM> described with reference to <FIG> or the table described with reference to <FIG>, but is not limited thereto.

The user may select a specific set value through the UI exposed on the display <NUM>-<NUM>, and the electronic device <NUM>-<NUM> may transmit a control command to change the set value to the wearable device <NUM>, <NUM>-<NUM>. Here, the control command to change the set value may include a set value selected by the user.

When the control command to change the set value is received from the electronic device <NUM>-<NUM>, the wearable device <NUM>, <NUM>-<NUM> may change the set value to the set value selected by the user according to the received control command and may transmit a control result of completion of a change in the set value to the electronic device <NUM>-<NUM>.

When the control result is received from the wearable device <NUM>, <NUM>-<NUM>, the electronic device <NUM>-<NUM> may display a message indicating the completion of the change in the set value on the display <NUM>-<NUM>.

There is no limitation to <FIG>, and the user may change the set value or input a new set value through the input interface <NUM>.

In response to a user input (or control command) to change the set value from "<NUM>" to "<NUM>," the processor <NUM> may change the set value from "<NUM>" to "<NUM>" so that a first graph <NUM> may be changed to a second graph <NUM>. When a difference between a reference angle and a first joint angle is greater than or equal to <NUM>°, the processor <NUM> may control the motor driver circuit <NUM> such that a resistance force may be output according to the second graph <NUM>. When the set value is "<NUM>" rather than "<NUM>," the user may be provided with the resistance force only when the user further moves the first joint.

In response to a user input (or control command) to change the set value from "<NUM>" to "-<NUM>," the processor <NUM> may change the set value from "<NUM>" to "-<NUM>" so that the first graph <NUM> may be changed to a third graph <NUM>. When the difference between the reference angle and a joint angle is greater than or equal to -<NUM>°, the processor <NUM> may control the motor driver circuit <NUM> such that the resistance force may be output according to the third graph <NUM>. When the set value is "-<NUM>" rather than "<NUM>," the user may be provided with the resistance force even though the first joint is less moved.

<FIG> is a diagram illustrating an example in which a wearable device outputs a resistance force using power of a battery while operating in a second resistance mode, according to an example embodiment.

In the second resistance mode, the control state of the motor driver circuit <NUM> may be repeatedly switched between the first control state and the second control state. Here, the motor <NUM> may output a resistance force instead of receiving power from the battery <NUM>.

According to an example embodiment, the processor <NUM> may control the motor driver circuit <NUM> so that the motor <NUM> may temporarily receive power from the battery <NUM> and may output a resistance force in the second resistance mode.

For example, when a difference between a reference angle and a joint angle is greater than a predetermined angle (e.g., θmotion1 in the graph of <FIG>), a resistance force with a maximum intensity may be output. In this example, when the difference between the reference angle and the joint angle continues to increase, the processor <NUM> may temporarily apply an ON signal to each of the first switch <NUM> and the fourth switch <NUM> as shown in <FIG>, instead of applying control signals <NUM> and <NUM> to the third switch <NUM> and the fourth switch <NUM>, respectively, so that a user may exercise more intensely. The motor <NUM> may temporarily receive power from the battery <NUM> and may output a resistance force with an intensity greater than the maximum intensity of the second resistance mode.

In a situation in which the ON signal is applied to each of the first switch <NUM> and the fourth switch <NUM>, when the difference between the reference angle and the joint angle decreases, the processor <NUM> may apply the control signals <NUM> and <NUM> to the third switch <NUM> and the fourth switch <NUM>, respectively, instead of applying the ON signal to each of the first switch <NUM> and the fourth switch <NUM>. Accordingly, the motor <NUM> may output the resistance force without a power supply from the battery <NUM>.

The wearable device <NUM> may output a resistance force by temporarily using battery power in the second resistance mode, so that the user may exercise more intensely in the second resistance mode.

<FIG> is a diagram illustrating an amplification of a resistance force through a gear in a wearable device according to an example embodiment.

Referring to <FIG>, a first gear <NUM> is attached to a rotation shaft of the motor <NUM>, and a second gear <NUM> is connected to the first gear <NUM>.

Since a number of teeth of the second gear <NUM> is greater than a number of teeth of the first gear <NUM>, a resistance force output from the motor <NUM> in the second resistance mode may be amplified by the first gear <NUM> and the second gear <NUM>, and the amplified resistance force may be provided to a user. The example embodiments are not limited thereto, and a resistance force output from the motor <NUM> in the first resistance mode may be amplified by the first gear <NUM> and the second gear <NUM>.

<FIG> and <FIG> are diagrams illustrating examples of wearable devices according to an example embodiment.

Referring to <FIG>, a wearable device <NUM> may include a sensor <NUM>, a processor <NUM>, a motor driver circuit <NUM>, a motor <NUM>, a memory <NUM>, an input interface <NUM>, and a battery <NUM>. Referring to <FIG>, a wearable device <NUM>-<NUM> may include a plurality of sensors <NUM> and <NUM>-<NUM>, a processor <NUM>, a plurality of motor driver circuits <NUM> and <NUM>-<NUM>, motors <NUM> and <NUM>-<NUM>, a memory <NUM>, an input interface <NUM>, and a battery <NUM>.

The wearable device <NUM> of <FIG> may operate in the first resistance mode as well as the second resistance mode, and thus the motor <NUM> of the wearable device <NUM> of <FIG> may require battery power. The battery <NUM> of the wearable device <NUM> of <FIG> may correspond to a battery of a high voltage (e.g., <NUM> V).

The wearable device <NUM> of <FIG> may be a device for the second resistance mode only. Since the motor <NUM> in the wearable device <NUM> does not require battery power, the battery <NUM> may correspond to a battery of a low voltage (e.g., <NUM> V).

In <FIG>, a thick arrow indicates a power supply of the battery <NUM>.

The battery <NUM> may supply power to components of the wearable device <NUM>, for example, the sensor <NUM> and the processor <NUM>. However, the battery <NUM> may not supply power to the motor <NUM> of the wearable device <NUM>. The battery <NUM> may be smaller in size than the battery <NUM> of the wearable device <NUM> of <FIG>, and thus the wearable device <NUM> may be lightened.

The wearable device <NUM>-<NUM> of <FIG> may operate in the first resistance mode as well as the second resistance mode, and thus the motors <NUM> and <NUM>-<NUM> of the wearable device <NUM>-<NUM> of <FIG> may require battery power.

The wearable device <NUM>-<NUM> of <FIG> may be a device for the second resistance mode only. Each of the motors <NUM> and <NUM>-<NUM> in the wearable device <NUM>-<NUM> may not require battery power.

The battery <NUM> of the wearable device <NUM>-<NUM> may supply power to components of the wearable device <NUM>-<NUM>. However, in <FIG>, the battery <NUM> does not supply power to each of the motors <NUM> and <NUM>-<NUM> of the wearable device <NUM>-<NUM>. The battery <NUM> of the wearable device <NUM>-<NUM> may be smaller in size than the battery <NUM> of the wearable device <NUM> of <FIG>, and thus the wearable device <NUM>-<NUM> may be lightened.

The description provided with reference to <FIG> may also apply to the description of <FIG> and <FIG>, and accordingly further description will be omitted for conciseness.

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 or DVDs; magneto-optical media such as optical discs or floptical disks; 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, 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 software may include a computer program, a piece of code, an instruction, or some combination thereof, to independently or collectively instruct or configure the processing device to operate as desired. 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.

Claim 1:
A wearable device (<NUM>, <NUM>-<NUM>, <NUM>, <NUM>-<NUM>), comprising:
a motor (<NUM>, <NUM>-<NUM>);
a motor driver circuit (<NUM>, <NUM>-<NUM>);
a memory (<NUM>) configured to store resistance force generation setting information indicating a difference between a reference angle and each of joint angles and a corresponding relationship between respective duty ratios;
a sensor (<NUM>, <NUM>-<NUM>); and
a processor (<NUM>) configured to obtain a joint angle of a user using the sensor (<NUM>, <NUM>-<NUM>), calculate a difference between the reference angle and the obtained joint angle, check a duty ratio corresponding to the calculated difference according to the resistance force generation setting information, and provide a control signal having the checked duty ratio to the motor driver circuit (<NUM>, <NUM>-<NUM>) so as to perform control such that a control state of the motor driver circuit (<NUM>, <NUM>-<NUM>) is switched between a first control state and a second control state,
wherein in the first control state, terminals of the motor (<NUM>, <NUM>-<NUM>) are in an equipotential state, and in the second control state, the terminals are electrically opened.