Patent Description:
A change into aging societies has contributed to a growing number of people who experience inconvenience and pain from reduced muscular strength or joint problems due to aging. Thus, there is a growing interest in walking assist devices that enable elderly users or patients with reduced muscular strength or joint problems to walk with less effort.

<CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT> disclose conventional devices and methods for providing resistance force to a user.

The invention is defined by the appended claims and is directed to a method of controlling a motor driver circuit of a wearable device according to claim <NUM>, a non-transitory computer-readable medium according to claim <NUM> and a wearable device according to claim <NUM>.

Any disclosure lying outside the scope of said claims, e.g. an assistance mode for such a wearable device, is only intended for illustrative as well as comparative purposes.

Some example embodiments relate to a method of controlling a motor driver circuit of a wearable device.

Some example embodiments relate to a wearable device configured to control a motor driver circuit of the wearable device.

Hereinafter, some example embodiments will be described in detail with reference to the accompanying drawings. Regarding the reference numerals assigned to the elements in the drawings, it should be noted that the same elements will be designated by the same reference numerals, wherever possible, even though they are shown in different drawings. Also, in the description of embodiments, detailed description of well-known related structures or functions will be omitted when it is deemed that such description will cause ambiguous interpretation of the present disclosure.

It should be understood, however, that there is no intent to limit this disclosure to the particular example embodiments disclosed. On the contrary, example embodiments are to cover all modifications, equivalents, and alternatives falling within the scope of the example embodiments. Like numbers refer to like elements throughout the description of the figures.

In addition, terms such as first, second, A, B, (a), (b), and the like may be used herein to describe components. It should be noted that if it is described in the specification that one component is "connected," "coupled," or "joined" to another component, a third component may be "connected," "coupled," and "joined" between the first and second components, although the first component may be directly connected, coupled or joined to the second component.

Unless otherwise defined, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure of this application pertains. Terms, such as those defined in commonly used dictionaries, are to be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art, and are not to be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In the drawings, the thicknesses of layers and regions are exaggerated for clarity.

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

Referring to <FIG>, a wearable device <NUM> may be worn on a user and configured to assist the user in walking more readily. For example, the wearable device <NUM> may be a device that assists the user in walking. The wearable device <NUM> may also be an exercise device that provides an exercise function by providing the user with a resistance force to assist the user in doing an exercise. The resistance force to be provided to the user may not be a force that is actively applied to the user, for example, a force output by a device such as a motor, but a force that hinders a movement of the user, for example, a force acting in a direction opposite to a direction in which the user moves. That is, the resistance force may also be referred to as an exercise load.

Although <FIG> illustrate an example of a hip-type wearable device, a type of a wearable device is not limited to the illustrated hip type, and the wearable device may be provided in a type that supports a whole lower body, supports a portion of the lower body, for example, a portion of the lower body up to a knee and a portion of the lower body up to an ankle, or supports a whole body.

Although example embodiments to be described hereinafter with reference to <FIG> are applicable to a hip-type wearable device, for example, the wearable device <NUM>, the example embodiments are not limited to the hip-type wearable device, but applicable to all types of wearable devices.

Referring to <FIG>, the wearable device <NUM> includes a driver <NUM>, a sensor <NUM>, an inertial measurement unit (IMU) <NUM>, a controller <NUM>, and a battery <NUM>.

The driver <NUM> includes a motor <NUM> and a motor driver circuit <NUM> configured to drive the motor <NUM>. The sensor <NUM> includes at least one sensor <NUM>. The controller <NUM> includes a processor <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>, examples are not limited thereto. For another example, 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>, as illustrated in <FIG>. In addition, according to implementation, the wearable device <NUM> may include a plurality of processors. The number of motor driver circuits, the number of motors, or the number of processors may vary according to a body part on which the wearable device <NUM> is to be worn.

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>.

The driver <NUM> may drive hip joints of the user wearing the wearable device <NUM>. For example, the driver <NUM> may be disposed in a portion of a right hip of the user and/or a portion of a left hip of the user. The driver <NUM> may be additionally disposed in a portion of knees of the user and a portion of ankles of the user. The driver <NUM> includes the motor <NUM> configured to generate a rotational torque and the motor driver circuit <NUM> configured to drive the motor <NUM>.

The sensor <NUM> may measure a hip joint angle of the user when the user walks. Here, information associated with the hip joint angle sensed by the sensor <NUM> may include an angle of a right hip joint, an angle of a left hip joint, a difference between the angle of the right hip joint and the angle of the left hip joint, and/or a hip joint movement direction. For example, the sensor <NUM> may be disposed in the driver <NUM>. Based on a position of the sensor <NUM>, the sensor <NUM> may additionally measure a knee angle of the user and an ankle angle of the user.

For example, the sensor <NUM> may include a potentiometer. The potentiometer may sense an R-axis joint angle and an L-axis joint angle, and an R-axis joint angular velocity and an L-axis joint angular velocity, based on a walking motion of the user.

The IMU <NUM> may measure acceleration information and pose information when the user walks. For example, the IMU <NUM> may sense an X-axis acceleration, a Y-axis acceleration, and a Z-axis acceleration, and an X-axis angular velocity, a Y-axis angular velocity, and a Z-axis angular velocity, based on a walking motion of the user.

The wearable device <NUM> may detect a point at which a foot of the user lands based on the acceleration information measured by the IMU <NUM>.

In addition, a pressure sensor (not shown) may be disposed on a sole of a foot of the user and detect a point in time at which the foot of the user lands.

In addition to the sensor <NUM> and the IMU <NUM>, the wearable device <NUM> may include other sensors configured to sense a change in a quantity of motion of the user or a change in biosignal based on a walking motion of the user. The sensors may include an electromyogram (EMG) sensor, for example.

According an example embodiment, the processor <NUM> of the controller <NUM> may control the driver <NUM> to provide a resistance force to the user. The driver <NUM> may provide the resistance force to the user through back-drivability of the motor <NUM> without outputting a torque to the user. Here, back-drivability of the motor <NUM> may indicate reactivity of a rotation axis of the motor <NUM> in response to an external force. For example, high back-drivability of the motor <NUM> may indicate readily responding to an external force applied to the rotation axis of the motor <NUM>, that is, the rotation axis of the motor <NUM> rotates readily. For example, even though the same external force is applied to the rotation axis of the motor <NUM>, a degree of a rotation of the rotation axis of the motor <NUM> may directly vary depending on a level of back-drivability.

A method of providing a resistance force to a user will be described in detail hereinafter with reference to <FIG>.

According another example embodiment, the processor <NUM> of the controller <NUM> may control the driver <NUM> to output a torque, for example, an assistance torque, to assist the user in walking. For example, the driver <NUM> may be provided as two drivers for the right hip and the left hip, respectively, in the wearable device <NUM> of the hip type, and the controller <NUM> may output a control signal for controlling the driver <NUM> such that the torque is generated.

The driver <NUM> may generate the torque based on the control signal output by the controller <NUM>. Here, a torque value used to generate the torque may be set externally or set by the controller <NUM>. For example, to indicate a magnitude of the torque value, the controller <NUM> may use a magnitude of a current with respect to a signal transmitted to the driver <NUM>. That is, as the magnitude of the current received by the driver <NUM> increases, the torque value may increase.

The battery <NUM> may provide power to components of the wearable device <NUM>. For example, there may be a circuit, for example, a power management integrated circuit (PMIC) that is configured to convert power of the battery <NUM> to an operating voltage of each of the components of the wearable device <NUM> and then provide the power to the components. In addition, the battery <NUM> may provide or not provide power to the motor <NUM> based on an operation mode of the wearable device <NUM>. That is, the battery <NUM> may provide power to the motor <NUM> in an assistance mode, and not provide power to the motor <NUM> in an exercise mode. Thus, less power may be consumed in the battery <NUM> in the exercise mode, and thus an available time for using the wearable device <NUM> may increase.

<FIG> is a diagram illustrating an example of a wearable device communicating with an electronic device according to at least one example embodiment.

Referring to <FIG>, the wearable device <NUM> may communicate with an electronic device <NUM>. The electronic device <NUM> may include, for example, a smartphone, a tablet personal computer (PC), a smart watch, eyeglasses, and the like, but examples are not limited thereto. For example, the electronic device <NUM> may be an electronic device associated with a user of the wearable device <NUM>. For another example, the user may do exercise together with a trainer with the wearable device <NUM> on. In such a case, the electronic device <NUM> may be an electronic device associated with the trainer.

According to implementation, the wearable device <NUM> and the electronic device <NUM> may communicate with each other via a server (not shown) using a short-range wireless communication method or a cellular mobile communication method.

The electronic device <NUM> may display, on a display <NUM>-<NUM>, a user interface (UI) for controlling an operation of the wearable device <NUM>. For example, the UI may include at least one softkey that enables the user to control the wearable device <NUM>.

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

<FIG> is a diagram illustrating an example of a gait state according to at least one example embodiment.

Referring to <FIG>, a gait state or a gait phase of one of legs of a user of a wearable device may be defined (or, alternatively, predefined). For example, the gait state may include a stance and a swing. The swing indicates a state in which a foot is away from the ground. A gait state of a left leg of the user may include a left stance (LSt) and a left swing (LSw), and a gait state of a right leg of the user may include a right stance (RSt) and a right swing (RSw).

In a finite-state machine (FSM), a gait cycle of such gait states or phases may be mapped in advance. For example, <NUM>% of the gait cycle may be mapped at a point in time at which a stance starts, <NUM>% of the gait cycle may be mapped at a point in time at which a swing starts, and <NUM>% of the gait cycle may be mapped at a point in time immediately before a next stance starts.

According to an example embodiment, the stance and the swing may be more elaborately classified into a plurality of states. The stance may be classified into, for example, an initial contact, a weight bearing, a middle stance, a terminal stance, and a pre-swing. In addition, the swing may be classified into, for example, an initial swing, a middle swing, and a terminal swing. However, the classification of the stance and the swing is not limited to the example classification described in the foregoing, and the stance and the swing may be differently classified according to examples.

<FIG> is a diagram illustrating an example of a transition in gait state according to at least one example embodiment.

Referring to <FIG>, according to a general gait mechanism, a gait state of each of both legs may include a stance and a swing, and the stance and the swing may occur alternately for walking.

A gait state <NUM> of a right leg according to a change <NUM> in the right leg by walking may include a right stance and a right swing. Here, the stance may include a weight bearing, a middle stance, and a terminal stance. However, examples are not limited to the illustrated example. A gait state <NUM> of a left leg according to a change (not shown) in the left leg with respect to the change <NUM> in the right leg may include a left stance and a left swing.

When muscular strength of an ankle of a user weakens due to aging or a disease, the user may experience inconvenience when walking. For example, when a leg starts swinging, a tip of a foot of the leg needs to be raised, but if not the swinging leg may hit the ground. That is, in such a case of a foot drop, there may be a risk of a fall. To prevent such a risk, an angle of the ankle may need to be adjusted based on a progression of a gait state or phase or a change in the gait state or phase. Thus, a wearable device may be provided to those who may have difficulty in adjusting an angle of an ankle themselves due to reduced muscular strength of the ankle. The wearable device may be worn around an ankle of a user and output an assistance torque based on a value sensed in association with walking or gait of the user. The assistance torque may be used to adjust an angle of the ankle of the user.

Although the example embodiment described above relates to assisting or supporting an ankle, the example embodiment may also be similarly and substantially applied to assisting or supporting a hip joint or a knee.

<FIG> is a diagram illustrating an example of a trajectory of an ankle joint angle with respect to a gait cycle according to at least one example embodiment.

Referring to <FIG>, when a user walks according to a general gait mechanism, an ankle joint angle of the user may change as shown in a trajectory <NUM>. Although an ankle joint angle may change even in the same gait state based on a stride and a walking speed, trajectories of an ankle joint angle with respect to one gait cycle may develop in a similar pattern. The trajectory <NUM> may have an illustrated range of changes in a progression of a gait cycle. The range of changes may include weight bearing <NUM>, middle stance <NUM>, terminal stance <NUM> and swing <NUM>.

However, the illustrated trajectory <NUM> may not be shown in an ankle joint angle of a leg of a patient who may experience inconvenience with the leg. Here, when the ankle joint angle of the leg from which the patient may experience inconvenience is adjusted such that the ankle joint angle of the leg has the trajectory <NUM>, a gait mechanism of the patient may be improved.

Although a trajectory of an ankle joint angle has been described above with reference to <FIG>, the foregoing description may be similarly and substantially applied to a hip joint ankle and a knee joint.

<FIG> is a diagram illustrating an example of a trajectory of an ankle torque with respect to a gait cycle according to at least one example embodiment.

Referring to <FIG>, what is to be described hereinafter with reference to <FIG> may be applied to a case in which the wearable device <NUM> operates in an assistance mode in which the wearable device <NUM> assists a user wearing the wearable device <NUM> in walking. A case in which the wearable device <NUM> operates in an exercise mode will be described in detail with reference to <FIG>.

When a user walks according to a general gait mechanism, an ankle torque to be output by an ankle joint of the user may change as shown in a trajectory <NUM>. A positive value of the ankle torque may increase an ankle joint angle, for example, enabling plantar flexion. A negative value of the ankle torque may decrease the ankle joint angle, for example, enabling dorsiflexion.

According to an example embodiment, a first portion <NUM> of the trajectory <NUM> of the ankle torque that corresponds to a segment after a push-off occurs may be an assistance torque value for the dorsiflexion to prevent a foot drop. The assistance torque value for the dorsiflexion may be a negative value.

A patient who may experience inconvenience with his/her leg may not generate a sufficient assistance torque himself/herself, and thus the patient may wear a wearable device on the leg from which the patient experiences inconvenience to receive the assistance torque. The wearable device may output the assistance torque through a driver and adjust an ankle angle. Here, the assistance torque for adjusting the ankle angle may need to be output at a desirable timing so that the user may not experience inconvenience. For example, a relatively high assistance torque for increasing the ankle angle may need to be provided at a time at which the leg performs a push-off. For example, the timing may be determined by directly determining a gait state of the leg from which the patient experiences inconvenience. For another example, the timing may be determined by indirectly determining a gait state of the leg based on a gait state of the other normal leg from which the patient does not experience inconvenience.

Hereinafter, a structure of the motor driver circuit <NUM> included in the driver <NUM> that enables the wearable device <NUM> to operate in an exercise mode that does not require use of the battery <NUM> will be described in detail with reference to <FIG>.

<FIG> are diagrams illustrating an example of a motor driver circuit of a wearable device according to at least one example embodiment.

Referring to <FIG>, the motor driver circuit <NUM> is an H-bridge circuit and includes a plurality of switches, for example, a first switch <NUM>, a second switch <NUM>, a third switch <NUM>, and a fourth switch <NUM>. The motor driver circuit <NUM> is connected to the motor <NUM>.

For example, when the first switch <NUM> and the fourth switch <NUM> are closed and the second switch <NUM> and the third switch <NUM> are open under the control of the processor <NUM>, a closed loop including the battery <NUM> may be formed. Thus, power may be provided to the motor <NUM> from the battery <NUM>. In such an example, the motor <NUM> may rotate in a first direction.

For another example, when the second switch <NUM> and the third switch <NUM> are closed and the first switch <NUM> and the fourth switch <NUM> are open under the control of the processor <NUM>, a closed loop including the battery <NUM> may be formed. Thus, power may be provided to the motor <NUM> from the battery <NUM>. In such an example, the motor <NUM> may rotate in a second direction which is opposite to the first direction.

Referring to <FIG>, the motor driver circuit <NUM> may be controlled such that a closed loop including the battery <NUM> is formed. The battery <NUM> may provide power to the motor <NUM>. The motor <NUM> may rotate in a direction corresponding to a direction of a current. For example, when the wearable device <NUM> operates in an assistance mode, the processor <NUM> may control the motor driver circuit <NUM> such that the closed loop including the battery <NUM> is formed.

Dissimilar to what is described above with reference to <FIG>, the motor driver circuit <NUM> may also be controlled such that the battery <NUM> is excluded. Such an example will be described hereinafter with reference to <FIG> and <FIG>. The example of controlling the motor driver circuit <NUM> as described hereinafter with reference to <FIG> and <FIG> may be used when an operation mode of the wearable device <NUM> is an exercise mode.

Referring to <FIG>, the processor <NUM> may block an electrical connection between the battery <NUM> and the motor <NUM> by opening the first switch <NUM> and the second switch <NUM>. In an exercise mode, the first switch <NUM> and the second switch <NUM> may remain opened. In the exercise mode, a lower driver circuit including the third switch <NUM> and the fourth switch <NUM> connected to the motor <NUM> may only be controlled.

The processor <NUM> may apply control signal <NUM> to the third switch <NUM> and apply control signal <NUM> to the fourth switch <NUM> such that a control state of the motor driver circuit <NUM> changes between a first control state and a second control state. Here, control signal <NUM> and control signal <NUM> may be in a form of a PWM in which a high value and a low value repeatedly alternate and have a duty ratio. The duty ratio may indicate a connection ratio. In a case in which one period is T and a time for which a high value is maintained in one period T is tH, the duty ratio is tH/T. Although the outputting of control signals <NUM> and <NUM> by the processor <NUM> is described herein, examples are not limited thereto. For example, the processor <NUM> may output a single control signal, and the output control signal may be divided by a separate circuit. Control signals obtained through the dividing may be applied to the third switch <NUM> and the fourth switch <NUM>, respectively.

For example, when control signals <NUM> and <NUM> are high values, a (+) terminal and a (-) terminal of the motor <NUM> may be connected to be in an equipotential state. That is, in the first control state, the (+) terminal and the (-) terminal of the motor <NUM> may be electrically connected 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> disposed around a corresponding joint of the user may rotate by the movement of the joint of the user. By such a rotation, an electromotive force or a potential difference may occur in the motor <NUM>. The terminals of the motor <NUM> in the first control state may be in the equipotential state, and thus a rotation resistance may be generated in the motor <NUM> to reduce the generated electromotive force. This rotation resistance may be provided to the user as a resistance force.

For example, when control signals <NUM> and <NUM> are low values, the (+) terminal and the (-) terminal of the motor <NUM> may be electrically opened. In the second control state, there is no electrical connection to the motor <NUM>. Thus, the second control state may also be referred to as an open loop state of the motor <NUM>.

When a user moves in the second control state, the motor <NUM> may rotate by the movement of the user. In the second control state, the (+) terminal and the (-) terminal of the motor <NUM> may be electrically opened, and thus an electromotive force may not occur in the motor <NUM> and the resistance force may not be output. That is, back-drivability of the motor <NUM> may increase, and a frictional force by a gear ratio may only be felt or experienced by the user as the resistance force.

Based on the high values and the low values of control signals <NUM> and <NUM> may repeat according to a PWM signal, and thus the control sate of the motor driver circuit <NUM> may be switched repeatedly 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 control signals <NUM> and <NUM>. For example, when a time for which a high value is maintained increases in a period of each of control signals <NUM> and <NUM> (that is, a time for which a low value is maintained decreases), 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 contrast, when a time for which a high value is maintained decreases in a period of each of control signals <NUM> and <NUM> (that is, a time for which a low value is maintained increase), a ratio of the motor <NUM> operating in the second 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 first 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 decrease.

In the exercise mode, the wearable device <NUM> may output a resistance force without providing power of the battery <NUM> to the motor <NUM>, and it is thus possible to consume less power of the battery <NUM> and increase an available time for using the wearable device <NUM>. When power of the battery <NUM> is provided to the motor <NUM>, the motor <NUM> may malfunction. However, in the exercise mode, the power of the battery <NUM> may not be provided to the motor <NUM>, and thus a potential malfunction of the motor <NUM> may be prevented and the safety of the wearable device <NUM> may be improved further.

Referring to <FIG>, the motor driver circuit <NUM> may be controlled not to include the battery <NUM>. The battery <NUM> may be electrically disconnected from the motor <NUM>. Based on a connection state of the motor driver circuit <NUM>, the motor <NUM> may generate an electromotive force (in a case in which the connection state corresponds to a closed loop) by an external force or may not generate the electromotive force (in a case in which the connection state corresponds to an open loop).

<FIG> is a flowchart illustrating an example of a method of providing a resistance force according to at least one example embodiment.

Operations <NUM> through <NUM> to be described hereinafter with reference to <FIG> may be performed by the wearable device <NUM>. Although the wearable device <NUM> is described above as being worn on a lower body of a user, examples of the wearable device <NUM> are not limited thereto. For example, the wearable device <NUM> may be worn on an upper body of a user. For another example, the wearable device <NUM> may be worn throughout a whole body of a user.

Referring to <FIG>, in operation <NUM>, the wearable device <NUM> receives, from a user, an operation mode that controls the wearable device <NUM>. The operation mode may include an exercise mode and an assistance mode, and the received operation mode may be the exercise mode or the assistance mode.

For example, the user may transmit the operation mode to the wearable device <NUM> through a user terminal connected to the wearable device <NUM> through a wireless network. The wearable device <NUM> may receive the operation mode through a communication module. The wireless network may include, for example, a cellular network, a Bluetooth network, a WiFi network, and the like, but examples are not limited thereto.

For another example, the user may input the operation mode through the input interface <NUM> of the wearable device <NUM>. The input interface <NUM> may include, for example, a physical button for receiving an input of the user, a software button formed based on a touch panel, a display and an indicator for outputting a state of the wearable device <NUM>, and the like. The indicator may be, for example, a light-emitting diode (LED), but examples are not limited thereto.

A plurality of dynamic modes that control the wearable device <NUM> may be provided in advance in the wearable device <NUM>.

For example, the wearable device <NUM> may control an operation of the wearable device <NUM> through a control algorithm. The control algorithm may be an algorithm that outputs a control value corresponding to an input including, for example, an input from the user and an input from the sensor <NUM>, the IMU <NUM>, and the like. For example, the control algorithm may operate based on a control table indicating an output value corresponding to input values.

For another example, the wearable device <NUM> may control an operation of the wearable device <NUM> based on a neural network corresponding to each operation mode rather than through a control algorithm. The neural network may be an artificial neural network, and be trained in advance through machine learning. The neural network may be, for example, a convolutional neural network (CNN), a recurrent neural network (RNN), a deep neural network (DNN), and a combination thereof, but examples are not limited thereto.

In response to an input being received, the neural network may output a result for the input. For example, when an angle of a joint is input, a neural network trained with the assistance mode may determine a gait state corresponding to the angle and calculate an assistance torque value for the joint. For another example, when an angle of a joint is input, a neural network trained with the exercise mode may determine a gait state corresponding to the angle and calculate and output a resistance level for the joint. In this example, the resistance level to be calculated may vary based on an exercise level set by the user. For example, when a higher exercise level is set, a higher resistance level may be calculated.

In operation <NUM>, the wearable device <NUM> measures an angle of a joint of the user using the sensor <NUM>. The sensor <NUM> may be an angle sensor, and measure an angle of at least one of a hip joint, a knee joint, or an ankle joint. Alternatively, respective angles of a plurality of joints may be measured. The angles of the joints that are simultaneously measured may form a joint angle set with respect to a certain time. The joint angle set may be used to determine a level of a gait cycle of the user. For example, a leg pose of the user may be determined based on a hip joint angle, a knee joint angle, and an ankle joint angle. In addition, the joint angle set may additionally include an angular acceleration calculated based on a variation in the same joint angle.

Although the hip joint, the knee joint, and the ankle joint are described herein as examples, the foregoing description may also be applied to other joints including, for example, a shoulder joint, an elbow joint, and a wrist joint.

Although operation <NUM> is illustrated as being performed between operations <NUM> and <NUM>, operation <NUM> may be performed continuously as long as power is provided to the sensor <NUM>. The sensor <NUM> may generate data including, for example, a joint angle, on a preset period. That is, the joint angle may be measured successively and continuously.

In operation <NUM>, the processor <NUM> of the wearable device <NUM> determines whether the operation mode is the exercise mode or the assistance mode. When the operation mode is the exercise mode, a resistance force may be provided to the user. When the operation mode is the assistance mode, an assistance force may be provided to the user. To provide the resistance force to the user, operations <NUM> through <NUM> may be performed. To provide the assistance force to the user, operations <NUM> and <NUM> may be performed.

Although it is described that the operation mode is determined in operation <NUM>, whether the operation mode is the assistance mode may be determined in operation <NUM> and then whether the operation mode is the exercise mode may be determined when the operation mode is determined not to be the assistance mode. Alternatively, whether the operation mode is the exercise mode may be determined in operation <NUM> and then whether the operation mode is the assistance mode may be determined when the operation mode is determined not to be the exercise mode.

According to an example embodiment, when the user walks, the exercise mode may be applied in the entire gait state, or selectively applied in a certain gait state. For example, the exercise mode may be applied only in a swing state between a stance state and the swing state as the user chooses. Here, to determine a current gait state of the user, the angle of the joint of the user may be used.

In operation <NUM>, when the operation mode is the exercise mode, the processor <NUM> of the wearable device <NUM> determines the resistance level for the joint based on the measured angle of the joint. For example, through the control algorithm, a resistance level for an input of a joint angle may be determined. For another example, a resistance level may be output by inputting a joint angle to a neural network determined based on the operation mode.

The resistance level refers to a level or magnitude of a resistance force the user may feel or experience. For example, when the user desires to receive the same resistance force for an entire gait motion (or a running motion), the same resistance level may be determined for the entire gait motion. For another example, when the user desires to receive a different resistance force for a certain state or phase of a gait mechanism (e.g., a swing state), a level of a gait cycle of the user may be determined based on a joint angle (e.g., a joint angle set) and a resistance level corresponding to the determined level of the gait cycle may be determined. The level of the gait cycle may change in real time, and thus the resistance level to be determined may change in real time.

According to an example embodiment, a resistance force profile generated in advance may indicate a trajectory of a resistance level with respect to an entire gait cycle. Based on the resistance force profile with respect to the entire gait cycle, a resistance level corresponding to a level of a current gait cycle may be determined.

The resistance profile may be adjusted by the user. For example, the user may adjust a resistance level of at least a portion of the resistance force profile through the input interface <NUM> of the wearable device <NUM> or a user terminal connected to the wearable device <NUM>. That is, the user may adjust a resistance level of at least a portion of the resistance force profile to set an exercise method desired by the user. The resistance force profile will be described in detail with reference to <FIG>.

Here, a neural network for each operation mode may be pretrained by a manufacturer of the wearable device <NUM>. In addition, the neural network may be additionally trained, for example, fine-tuned, by the user of the wearable device <NUM>. For example, the user may input feedback on a current output of the neural network to the wearable device <NUM>, and the processor <NUM> may additionally train the neural network such that the feedback is reflected. For example, to train the neural network, backpropagation or reinforcement learning may be used, but examples are not limited thereto.

According to an example embodiment, the resistance level may be determined based on a position and an angle of a joint of the user. For example, a target pose of a left leg of the user may be set in advance, and a resistance level may be determined based on a difference between the target pose and a current pose of the user. In this example, when the difference between the target pose and the current pose is great, the resistance level may be determined to be small. In contrast, when the difference between the target pose and the current pose is small, the resistance level may be determined to be great. In addition, when the current pose corresponds to the target pose, a maximum resistance level may be provided to the user.

For example, in a case in which a pose of lifting a thigh by a preset or greater angle is set as the target pose, a resistance level may be greater when the user lifts the thigh higher, and the user may feel or experience a strongest resistance force from the target pose.

To determine a resistance level, a damping control technology to which a muscle model is applied may be used. When resistance levels determined through the damping control technology change in sequential order, a sense of resistance the user may feel or experience against a change in exercise load may be reduced.

According to a biological muscle model (e.g., a hill-type muscle model developed in medical engineering) that is generally known, when a stimulus signal is input to muscle, the input stimulus signal may be amplified in proportion to a force generated by the muscle (which is positive feedback), and muscular strength (or a force) amplified by the stimulus signal may have a relational expression by a length of the muscle and a contraction speed of the muscle.

When the muscle is contracted most and when the muscle is stretched most, there may not be a great force. However, when the muscle has an appropriate length, the muscle may have strongest power. A force generated based on a speed at which the length of the muscle changes may be greater when the speed of the change increases.

A relationship between the length of the muscle and the muscular strength of the muscle based on the length of the muscle may be in a form of a normal distribution. A relationship between the muscle stretching speed and the muscular strength of the muscle based on the muscle stretching speed may be in a form of a sigmoid.

The user may be familiar with a change in a physical movement based on the stretching of the muscle and the magnitude of the corresponding strength or force. Thus, when a resistance level corresponding to the magnitude of the force exhibited in response to the change in the physical movement is provided to the user, the user may also become familiar with a resistance force (or an exercise load) provided by the resistance level and a change in the resistance force based on a change in the resistance level.

The wearable device <NUM> may calculate a physical movement of the user based on a position and an angle of a joint of the user. In the exercise mode, the processor <NUM> of the wearable device <NUM> may calculate the physical movement and the magnitude of the corresponding force by the movement, based on the position and the angle of the joint of the user, and calculate a control level based on the calculated magnitude of the force.

In operation <NUM>, the processor <NUM> of the wearable device <NUM> determines a ratio between a time for which the motor driver circuit <NUM> is controlled to be a closed loop and a time for which the motor driver circuit <NUM> is controlled to be an open loop, based on the resistance level. Here, the ratio between the time for which the motor driver circuit <NUM> is controlled to be the closed loop and the time for which the motor driver circuit <NUM> is controlled to be the open loop may also be referred to as a connection ratio. For example, the connection ratio of the motor driver circuit <NUM> corresponding to the resistance level may be determined. The connection ratio of the motor driver circuit <NUM> may indicate a ratio at which the motor driver circuit <NUM> is controlled to be the closed loop (e.g., the first control state) or the open loop (e.g., the second control state) while energy is controlled not to be provided to the motor <NUM> from the battery <NUM>. For example, based on a closed loop state, the connection ratio being <NUM> may indicate that the closed loop state is controlled to be <NUM>% and an open loop state is controlled to be <NUM>% in a set (or, alternatively, a preset) period. When the resistance level changes, the connection ratio may be dynamically adjusted.

For example, the connection ratio may be implemented using a PWM. However, examples are not limited to the foregoing example, and various methods may be applied to adjust a connection state of the motor driver circuit <NUM>. When the PWM is used to control the connection ratio, the connection ratio determined in operation <NUM> may be represented by a PWM having a certain duty ratio. The PWM having the duty ratio may be set (or, alternatively, preset) such that a desired resistance force is provided to the user. By the PWM having the duty ratio, the motor driver circuit <NUM> may be controlled to be the closed loop (first control state) or the open loop (second control state). For example, the processor <NUM> may control the motor driver circuit <NUM> to be the closed loop or the open loop by controlling an operation of each of switches in the motor driver circuit <NUM> using the PWM.

When the motor driver circuit <NUM> is the closed loop, the motor <NUM> may operate as a generator, and back-drivability of the motor <NUM> may decrease by dynamic braking. When the back-drivability decreases, a resistance force the user may feel or experience may increase. In contrast, when the motor driver circuit <NUM> is the open loop, the back-drivability of the motor <NUM> may increase, and only a frictional force by a gear ratio may be experienced by the user as a resistance force.

A desired back-drivability may be obtained by adjusting an open-closed state ratio of the motor driver circuit <NUM> based on the connection ratio. For example, the resistance force to be provided to the user may be adjusted by the ratio at which the motor driver circuit <NUM> is controlled to be the closed loop or the open loop within a uniform and repetitive time interval of the PWM, and the resistance force may increase when the ratio of the time for controlling the motor driver circuit <NUM> to be the closed loop increases.

In operation <NUM>, the processor <NUM> of the wearable device <NUM> controls the motor <NUM> through the motor driver circuit <NUM> based on the determined connection ratio. The motor driver circuit <NUM> may include at least one switch (e.g., the first to fourth switches <NUM>-<NUM>) to be controlled based on the connection ratio, and the motor driver circuit <NUM> may be controlled to be the closed loop or the open loop by the switch. When the exercise mode is set as the operation mode of the wearable device <NUM>, energy of the wearable device <NUM> may not be provided to the motor <NUM>. For example, electric energy stored in the battery <NUM> of the wearable device <NUM> may not be provided to the motor <NUM>. In this example, although the electric energy is not provided to the motor <NUM>, the back-drivability of the motor <NUM> may be controlled by controlling the motor driver circuit <NUM> to be the closed loop or the open loop, and thus the resistance force may be adjusted by the controlled back-drivability.

When the user does not move, the motor <NUM> may not operate as the generator. When the motor <NUM> does not operate as the generator, the resistance force may not be generated and provided to the user. That is, the resistance force that is generated based on the back-drivability of the motor <NUM> may only occur when the user moves.

When the motor <NUM> operates as the generator, the battery <NUM> of the wearable device <NUM> may be charged based on energy generated by the generator. That is, while the wearable device <NUM> is operating in the exercise mode, the energy of the battery <NUM> of the wearable device <NUM> may be consumed considerably less, but charged instead. When the wearable device <NUM> operates in the exercise mode, the wearable device <NUM> may continue operating even when energy is not supplied from outside.

Operations <NUM> through <NUM> described above may be performed when the operation mode of the wearable device <NUM> is set as the exercise mode. Operations <NUM> and <NUM> to be described hereinafter may be performed when the operation mode of the wearable device <NUM> is set as the assistance mode.

In operation <NUM>, when the assistance mode is received as an input from the user, the processor <NUM> of the wearable device <NUM> calculates an assistance torque value for the joint based on the measured angle of the joint. For example, the assistance torque value for the input joint angle may be determined through the control algorithm. For another example, the assistance torque value may be output by inputting the joint angle to the neural network determined based on the operation mode.

According to an example embodiment, the processor <NUM> may determine a gait state or phase, or a progression of a gait cycle, of the user based on the angle of the j oint, and determine an assistance torque value corresponding to the determined gait state or the determined progression of the gait cycle. For example, when the number of joints to be measured increases, a more accurate gait state or a more accurate progression of a gait cycle may be determined.

For example, the assistance torque value may be determined based on a desired (or, alternatively, a preset) torque profile. However, a method of calculating an assistance torque value is not limited to the foregoing example.

In operation <NUM>, the processor <NUM> of the wearable device <NUM> provides an assistance force to the user by controlling the motor <NUM> based on the assistance torque value. The wearable device <NUM> may operate or drive the motor <NUM> using the battery <NUM> of the wearable device <NUM> such that an assistance torque is output, and provide the assistance force to the user by the assistance torque output by the motor <NUM>. The assistance torque value may indicate a control signal applied to the motor <NUM>, and the assistance torque may indicate a rotation torque output by the motor <NUM> based on the assistance torque value. The assistance force may indicate a force the user may feel or experience by the assistance torque.

Although the wearable device <NUM> is described with reference to <FIG> as providing both the exercise mode and the assistance mode to a user, the wearable device <NUM> may operate only in the exercise mode. In a case in which the wearable device <NUM> operates only in the exercise mode, operations <NUM>, <NUM>, <NUM>, and <NUM> described above may not be performed. In addition, the wearable device <NUM> may not include a battery to provide power to the motor <NUM>. When the battery is not included, the wearable device <NUM> may be lightened in terms of weight.

<FIG> is a diagram illustrating an example of a resistance force profile output from a user terminal according to at least one example embodiment.

Referring to <FIG>, the wearable device <NUM> may be connected to a user terminal <NUM> through a wired or wireless network. For example, the wearable device <NUM> may transmit and receive information associated with the wearable device <NUM> through an application installed in the user terminal <NUM>. The information associated with the wearable device <NUM> may include, for example, a setting value of the wearable device <NUM>, an operation state of the wearable device <NUM>, a device state of the wearable device <NUM>, and the like. The setting values of the wearable device <NUM> may include, for example, detailed setting values that are set by a user for an assistance mode or an exercise mode. The operation state of the wearable device <NUM> may include, for example, a current gait state of the user or a progression of a gait cycle. The device state of the wearable device <NUM> may include, for example, a residual amount of the battery <NUM>.

Various resistance force profiles associated with the exercise mode may be stored in advance in the wearable device <NUM> or the user terminal <NUM>. For example, the resistance force profiles may be generated in advance to produce different exercise effects.

The user may individualize an existing resistance force profile <NUM> by adjusting at least a portion <NUM> of the resistance force profile <NUM> to be a resistance level desired by the user. For example, the portion <NUM> may correspond to a swing state, and the user may adjust the resistance level of the portion <NUM> such that the resistance level is to be almost minimized in the swing state. For example, the user may adjust the resistance level by touching the portion <NUM> through a touch panel of the user terminal <NUM> and dragging a trajectory of the selected portion <NUM>.

<FIG> is a flowchart illustrating another example of a method of providing a resistance force according to at least one example embodiment.

Operations <NUM> through <NUM> to be described hereinafter with reference to <FIG> may be performed by the wearable device <NUM>.

Referring to <FIG>, in operation <NUM>, the wearable device <NUM> receives, from a user, an operation mode that controls the wearable device <NUM>. For a more detailed description of operation <NUM>, reference may be made to the description of operation <NUM> provided above with reference to <FIG>.

In operation <NUM>, the wearable device <NUM> measures an angle of a joint of the user using the sensor <NUM>. For a more detailed description of operation <NUM>, reference may be made to the description of operation <NUM> provided above with reference to <FIG>. Operation <NUM> may be independently performed with operation <NUM> in parallel.

In operation <NUM>, the wearable device <NUM> determines whether the operation mode is an exercise mode or an assistance mode.

For example, in a case in which the wearable device <NUM> operates based on a plurality of neural networks, the wearable device <NUM> may determine a neural network corresponding to the determined operation mode. Based on the determined neural network, subsequent operations may be performed. For example, an exercise mode neural network may be determined for the exercise mode, and an assistance mode neural network may be determined for the assistance mode. When the operation mode is the exercise mode, operations <NUM> through <NUM> may be performed. When the operation mode is the assistance mode, operations <NUM> and <NUM> may be performed.

Although it is described above that the exercise mode or the assistance mode operates based on its corresponding neural network, examples are not limited thereto. For example, an operation of the wearable device <NUM> may be controlled through a control algorithm, not such a neural network.

In operation <NUM>, the processor <NUM> of the wearable device <NUM> determines a resistance level for the joint based on the measured angle of the joint. For a more detailed description of operation <NUM>, reference may be made to the description of operation <NUM> provided above with reference to <FIG>.

In operation <NUM>, the processor <NUM> of the wearable device <NUM> determines a connection ratio of the motor driver circuit <NUM> corresponding to the resistance level. For a more detailed description of operation <NUM>, reference may be made to the description of operation <NUM> provided above with reference to <FIG>.

In operation <NUM>, the processor <NUM> of the wearable device <NUM> controls the motor <NUM> through the connection ratio of the motor driver circuit <NUM>. For a more detailed description of operation <NUM>, reference may be made to the description of operation <NUM> provided above with reference to <FIG>.

In operation <NUM>, the processor <NUM> of the wearable device <NUM> calculates an assistance torque value for the joint based on the measured angle of the joint. For a more detailed description of operation <NUM>, reference may be made to the description of operation <NUM> provided above with reference to <FIG>.

In operation <NUM>, the processor <NUM> of the wearable device <NUM> provides an assistance force to the user by controlling the motor <NUM> based on the assistance torque value. For a more detailed description of operation <NUM>, reference may be made to the description of operation <NUM> provided above with reference to <FIG>.

<FIG> is a diagram illustrating an example of a motor driver circuit of an open loop according to at least one example embodiment.

Referring to <FIG>, a motor driver circuit <NUM> may be an H-bridge circuit. The motor driver circuit <NUM> may have an open or closed state that is determined based on a connection state of switches <NUM> through <NUM>. The switches <NUM> through <NUM> may be embodied as, for example, a bipolar junction transistor (BJT) and a metal-oxide-semiconductor field-effect transistor (MOSFET), but examples are not limited thereto.

When the motor driver circuit <NUM> is in an open circuit state, dynamic braking of the motor <NUM> may be minimized, and thus back-drivability of the motor <NUM> may increase. In such a case, the back-drivability may be a frictional force generated by gears connected to the motor <NUM>.

<FIG> and <FIG> are diagrams illustrating examples of a motor driver circuit of a closed loop according to at least one example embodiment.

According to an example embodiment, a closed loop of the motor driver circuit <NUM> may be formed to include the battery <NUM> and the motor <NUM>.

For example, when the switches <NUM> and <NUM> of the motor driver circuit <NUM> are open and the switches <NUM> and <NUM> of the motor driver circuit <NUM> are closed, a current provided to the motor <NUM> may flow in a first direction <NUM>.

For another example, when the switches <NUM> and <NUM> are closed and the switches <NUM> and <NUM> are open, a current provided to the motor <NUM> may flow in a second direction <NUM>. The second direction <NUM> may be a direction opposite to the first direction <NUM>. Based on such a current direction, a rotation direction of an axis of the motor <NUM> may change.

These example closed loops may be formed in a case of an assistance mode, and the example current directions <NUM> and <NUM> may be determined based on a direction of an assistance force to be provided to a user.

<FIG> is a diagram illustrating an example of a motor driver circuit of a closed loop according to at least one example embodiment.

Referring to <FIG>, the motor driver circuit <NUM> connected to the motor <NUM> that is controlled not to use energy of the battery <NUM> may form a closed loop. That is, in the example of <FIG>, the motor driver circuit <NUM> may be a motor driver circuit for an exercise mode that does not use power of the battery <NUM> and a closed loop circuit connected to the motor <NUM>.

For example, when the switches <NUM> and <NUM> of the motor driver circuit <NUM> are open and the switches <NUM> and <NUM> of the motor driver circuit <NUM> are closed, a closed loop including the motor <NUM> may be formed. That is, the closed loop may be formed by a lower driver circuit of the motor driver circuit <NUM>. The closed loop may be formed in a case of the exercise mode, and dynamic braking of the motor <NUM> may occur. A user who rotates the motor <NUM> may feel or experience a resistance force by the dynamic braking.

<FIG> is a diagram illustrating an example of a motor driver circuit of a closed loop including a braking resistor according to at least one example embodiment.

Referring to <FIG>, a motor driver circuit <NUM> includes the battery <NUM>, switches <NUM> through <NUM> connected to the motor <NUM>, and a braking resistor <NUM>. The switches <NUM> and <NUM> are closed, and thus a closed loop including the motor <NUM> may be formed. When the closed loop is formed, a resistance force that may be felt or experienced by a user may be maximized.

When a ratio of an open loop state and a closed loop state of the motor driver circuit <NUM> is adjusted by a connection ratio, a level of the resistance force may be adjusted. The closed loop state may be maintained to maximize the resistance force, and the open loop state may be maintained to minimize the resistance force.

For example, in a state in which the motor driver circuit <NUM> is controlled to be the closed loop, the motor <NUM> may operate as a generator for an external force by the user, and generated energy may be consumed as heat through the braking resistor <NUM>. For another example, in the motor driver circuit <NUM>, a current which is the energy generated by the motor <NUM> may flow in a direction from a (+) terminal of the battery <NUM> to a (-) terminal of the battery <NUM> by a diode, regardless of a rotation direction of a rotation axis of the motor <NUM>. Thus, the generated energy may charge the battery <NUM>.

<FIG> is a diagram illustrating an example of a motor driver circuit of a closed loop including a resistor according to at least one example embodiment.

Referring to <FIG>, a motor driver circuit <NUM> obtained by adding an auxiliary path including at least one resistor <NUM> and switch <NUM> to the motor driver circuit <NUM> described above with reference to <FIG> may increase electrical stability of a closed loop.

In the motor driver circuit <NUM> in a closed loop state including the motor <NUM>, the motor <NUM> may operate as a generator while rotating by an external force and generate an electromotive force. By the generated electromotive force, there may be a probability that electronic components in the closed loop are damaged. Thus, by adding the resistor <NUM> to the closed loop, an internal resistance value of the closed loop may increase, and thus a magnitude of a current generated by the electromotive force may decrease. As the magnitude of the current decreases, the probability that the internal electronic components in the closed loop are damaged may also be reduced.

<FIG> s a diagram illustrating an example of a motor driver circuit of a closed loop including a brushless direct current (BLDC) motor according to at least one example embodiment.

The motor driver circuits <NUM>, <NUM>, and <NUM> illustrated in <FIG> may be connected to a direct circuit (DC) motor. Referring to <FIG>, as another example, a motor driver circuit <NUM> may be connected to a BLDC motor <NUM>. The BLDC motor <NUM> may be connected to three terminals in the motor driver circuit <NUM>. In general, compared to a DC motor, a BLDC motor may generate a torque that is great relative to a volume, and may not have a friction generated between a brush and a rotor coil because it does not use a mechanical brush that is used in the DC motor for commuting a current. Since there is no friction between the brush and the rotor coil, the BLDC motor may have a greater durability than the DC motor.

For example, when switches <NUM>, <NUM>, and <NUM> of the motor driver circuit <NUM> are open, and switches <NUM>, <NUM>, and <NUM> of the motor driver circuit <NUM> are closed, a closed loop including the BLDC motor <NUM> may be formed. The closed loop may be formed with the battery <NUM> excluded.

As a PWM signal is applied to the switches <NUM>, <NUM>, and <NUM>, a closed loop state and an open loop state of the motor driver circuit <NUM> may be controlled. Here, a control ratio may change according to a resistance level.

The switch <NUM> may control opening and closing of a first terminal (u) of the BLDC motor <NUM>. The switch <NUM> may control opening and closing of a second terminal (v) of the BLDC motor <NUM>. The switch <NUM> may control opening and closing of a third terminal (w) of the BLDC motor <NUM>. For example, when the same PWM signal is applied to the switches <NUM>, <NUM>, and <NUM>, a closed loop that is not related to a commutation sequence for the BLDC motor <NUM> may be formed.

Since the BLDC motor <NUM> are connected to the three terminals u, v, and w, it may possible to form a closed loop by determining hall sensor information (e.g., an angle of a rotation axis of a motor) of a rotor and then selectively connecting two switches among the switches <NUM>, <NUM>, and <NUM> to match the commutation sequence, in order to form an electrical closed loop among the terminals u, v, and w. However, in a case in which the BLDC motor <NUM> is controlled to control only back-drivability of the BLDC motor <NUM> in an exercise mode, it is possible to form a closed loop by connecting all the switches <NUM>, <NUM>, and <NUM>, without considering the commutation sequence. In such a case, there is no need to consider the commutation sequence to form the closed loop, a time needed for calculating the commutation sequence may be reduced and a probability of a malfunction of the BLDC motor <NUM> may also be reduced.

For another example, a PWM signal may be applied to each of the switches <NUM>, <NUM>, and <NUM> to form a closed loop corresponding to a commutation sequence for a state classified based on an angle of a rotation axis of the BLDC motor <NUM>.

<FIG> is a diagram illustrating an example of a driver of a wearable device according to at least one example embodiment.

Referring to <FIG>, the driver <NUM> of the wearable device <NUM> includes a motor <NUM>, a clutch <NUM>, and a plurality of gears including a low reduction gear <NUM> and a high reduction gear <NUM>. From among the gears, different gears may be selected according to an input of a user or a determined resistance level. The clutch <NUM> may control driving force transfer by selectively connecting the motor <NUM> to one of the gears.

A gear ratio may be differently set based on an objective of an operation mode of the wearable device <NUM>, and thus a magnitude of a resistance force to be provided to the user may be adjusted.

Unlike the hip-type wearable device <NUM> described above with reference to <FIG>, a wearable device may be a whole body-type wearable device <NUM> to be described hereinafter with reference to <FIG>. The whole body-type wearable device <NUM> may be configured to provide a walking assistance torque respectively to a hip joint, a knee joint, and an ankle joint of a user.

<FIG> are diagrams illustrating an example of a whole body-type wearable device <NUM> according to at least one example embodiment.

<FIG> is a front view of the whole body-type wearable device <NUM>, <FIG> is a side view of the whole body-type wearable device <NUM>, and <FIG> is a rear view of the whole body-type wearable device <NUM>.

According to an example embodiment, the whole body-type wearable device <NUM> may include the driver <NUM>, the sensor <NUM>, the IMU <NUM>, the controller <NUM>, and the battery <NUM> that are described above.

Referring to <FIG>, the whole body-type wearable device <NUM> may be provided in an exoskeleton structure to be worn on a left leg and a right leg of a user. With the wearable device <NUM> on, the user may be able to perform various movements, for example, extension, flexion, adduction, and abduction. The extension may indicate a movement or an exercise of stretching joints, and the flexion may indicate a movement or an exercise of bending joints. The adduction may indicate a movement or an exercise of moving legs to be closer to a central axis of a body, and the abduction may indicate a movement or an exercise of stretching legs in a direction receding from a central axis of a body.

Referring to <FIG>, the wearable device <NUM> includes a main body portion <NUM> and a device portion including 20R and <NUM>, 30R and <NUM>, and 40R and <NUM>.

The main body portion <NUM> includes a housing <NUM> in which various components are embedded. The components to be embedded in the housing <NUM> may include, for example, a central processing unit (CPU), a printed circuit board (PCB), various types of storage devices, and a power source. Although not illustrated, the whole body-type wearable device <NUM> may also include the driver <NUM>, the sensor <NUM>, the IMU <NUM>, and the controller <NUM> that are described above. For example, the main body portion <NUM> may include the controller <NUM>, where the controller <NUM> may include the CPU and the PCB.

The CPU may be a microprocessor. The microprocessor may be provided with an arithmetic logic operator, a register, a program counter, an instruction decoder, and/or a control circuit in a silicon chip. The CPU may select a control mode that is suitable for a walking environment, and generate a control signal to control an operation of the device portion.

The PCB refers to a board on which a circuit is printed, and the CPU and/or the various storage devices may be installed in the PCB. The PCB may be fixed to an inner side surface of the housing <NUM>.

The various types of storage devices may be embedded in the housing <NUM>. The storage devices may include a magnetic disk storage device configured to magnetize a magnetic disk surface and store data, and a semiconductor memory device configured to store data using various types of memory semiconductors.

The power source embedded in the housing <NUM> may supply power to the various components embedded in the housing <NUM> or the device portion.

The main body portion <NUM> further includes a waist support <NUM> configured to support a waist of the user. The waist support <NUM> may be provided in a shape of a curved flat surface plate that supports the waist of the user.

The main body portion <NUM> further includes a fixing portion 11a configured to fix the housing <NUM> to a hip portion of the user, and a fixing portion 12a configured to fix the waist support <NUM> to the waist of the user. The fixing portions 11a and 12a may be embodied by one of a band, a belt, and a strap which are elastic.

The main body portion <NUM> also includes the IMU <NUM>. For example, the IMU <NUM> may be provided inside or outside the housing <NUM>. The IMU <NUM> may be provided on the PCB provided inside the housing <NUM>. The IMU <NUM> may measure an acceleration and an angular velocity.

The device portion includes a first structure <NUM>, a second structure <NUM>, and a third structure <NUM> as illustrated in <FIG>.

The first structure <NUM> including right 20R and left <NUM> portions may assist or support a movement of a thigh and a hip joint of the user when the user walks. The first structure <NUM> includes a first driving device including 21R and <NUM>, a first support including 22R and <NUM>, and a first fixing portion including 23R and <NUM>.

The driver <NUM> may include the first driving device including 21R and <NUM>. The description of the driver <NUM> may be replaced with the description of the first driving device including 21R and <NUM> to be provided hereinafter with reference to <FIG>.

The first driving device including 21R and <NUM> may be disposed on the hip joint of the first structure <NUM> including 20R and <NUM>, and generate a rotational force of different magnitudes in a certain direction. The rotational force generated in the first driving device including 21R and <NUM> may be applied to the first support including 22R and <NUM>. The first driving device including 21R and <NUM> may be set to rotate within a motion range of a hip joint of a human body.

The first driving device including 21R and <NUM> may operate based on a control signal provided by the main body portion <NUM>. The first driving device including 21R and <NUM> may be embodied by one of a motor, a vacuum pump, and a hydraulic pump, but examples are not limited thereto.

A joint angle sensor may be provided around the first driving device including 21R and <NUM>. The joint angle sensor may detect an angle by which the first driving device including 21R and <NUM> rotates on a rotation axis. The sensor <NUM> may include the joint angle sensor.

The first support including 22R and <NUM> may be physically connected to the first driving device including 21R and <NUM>. The first support including 22R and <NUM> may rotate in a certain direction by the rotational force generated from the first driving device including 21R and <NUM>.

The first support including 22R and <NUM> may be provided in various shapes. For example, the first support including 22R and <NUM> may be provided in a shape in which nodes are connected with each other. A joint may be between the nodes, by which the first support including 22R and <NUM> may be bent within a certain range. For another example, the first support including 22R and <NUM> may be provided in a shape of a rod. In this example, the first support including 22R and <NUM> may be formed with a flexible material that may be bent within a certain range.

The first fixing portion including 23R and <NUM> may be provided in the first support including 22R and <NUM>. The first fixing portion including 23R and <NUM> may fix the first support including 22R and <NUM> to the thigh of the user.

<FIG> illustrate that the first support including 22R and <NUM> is fixed on an outer side of the thigh of the user by the first fixing portion including 23R and <NUM>. When the first driving device including 21R and <NUM> operates and the first support including 22R and <NUM> rotates, the thigh to which the first support including 22R and <NUM> is fixed may also rotate in a same direction as a rotation direction in which the first support including 22R and <NUM> rotates.

The first fixing portion including 23R and <NUM> may be embodied by one of a band, a belt, and a strap which are elastic, or by a metal material. <FIG> illustrates the first fixing portion including 23R and <NUM> as a chain.

The second structure <NUM> including right 30R and left <NUM> portions may assist or support a movement of a calf and a knee j oint of the user when the user walks. The second structure <NUM> including 30R and <NUM> includes a second driving device including 31R and <NUM>, a second support including 32R and <NUM>, and a second fixing portion including 33R and <NUM>.

The second driving device including 31R and <NUM> may be disposed on the knee joint of the second structure <NUM> including 30R and <NUM>, and generate a rotational force of different magnitudes in a certain direction. The rotational force generated in the second driving device including 31R and <NUM> may be applied to the second support including 32R and <NUM>. The second driving device including 31R and <NUM> may be set to rotate within a motion range of a knee joint of a human body.

The driver <NUM> may include the second driving device including 31R and <NUM>. Here, what has been described above in relation to a hip joint with reference to <FIG> may be similarly and substantially applied to the knee joint.

The second driving device including 31R and <NUM> may operate based on a control signal provided by the main body portion <NUM>. The second driving device including 31R and <NUM> may be embodied by one of a motor, a vacuum pump, and a hydraulic pump, but examples are not limited thereto.

A joint angle sensor may be provided around the second driving device including 31R and <NUM>. The joint angle sensor may detect an angle by which the second driving device including 31R and <NUM> rotates on a rotation axis. The sensor <NUM> may include the joint angle sensor.

The second support including 32R and <NUM> may be physically connected to the second driving device including 31R and <NUM>. The second support including 32R and <NUM> may rotate in a direction by the rotational force generated from the second driving device 31R and <NUM>.

The second fixing portion including 33R and <NUM> may be provided in the second support including 32R and <NUM>. The second fixing portion including 33R and <NUM> may fix the second support including 32R and <NUM> to the calf of the user. <FIG> illustrate that the second support including 32R and <NUM> is fixed on an outer side of the calf of the user by the second fixing portion including 33R and <NUM>. When the second driving device including 31R and <NUM> operates and the second support including 32R and <NUM> rotates, the calf to which the second support including 32R and <NUM> is fixed may also rotate in a same direction as a rotation direction in which the second support including 32R and <NUM> rotates.

The second fixing portion including 33R and <NUM> may be embodied by one of a band, a belt, and a strap which are elastic, or by a metal material.

The third structure <NUM> including right 40R and left <NUM> portions may assist or support a movement of an ankle joint and related muscles of the user when the user walks. The third structure <NUM> including 40R and <NUM> includes a third driving device including 41R and <NUM>, a foot support including 42R and <NUM>, and a third fixing portion including 43R and <NUM>.

The driver <NUM> may include the third driving device including 41R and <NUM>. Here, what has been described above in relation to a hip joint withe reference to <FIG> may be similarly and substantially applied to the ankle joint.

The third driving device including 41R and <NUM> may be disposed on the ankle joint of the third structure <NUM> including 40R and <NUM>, and operate based on a control signal provided by the main body portion <NUM>. Similar to the first driving device including 21R and <NUM> or the second driving device including 30R and <NUM>, the third driving device including 41R and <NUM> may be embodied by a motor.

The foot support including 42R and <NUM> may be disposed at a position corresponding to a sole of a foot of the user, and physically connected to the third driving device including 41R and <NUM>.

The third fixing portion including 43R and 43R may be provided in the foot support including 42R and <NUM>. The third fixing portion including 43R and <NUM> may fix the foot of the user to the foot support including 42R and <NUM>.

The units and/or modules described herein may be implemented using hardware components and software components. For example, the hardware components may include microphones, amplifiers, band-pass filters, audio to digital convertors, and processing devices. A processing device may be implemented using one or more hardware device configured to carry out and/or execute program code by performing arithmetical, logical, and input/output operations. The processing device(s) may include a processor, a controller and an arithmetic logic unit, a digital signal processor, a microcomputer, a field programmable array, a programmable logic unit, a microprocessor or any other device capable of responding to and executing instructions in a defined manner. The processing device may run an operating system (OS) and one or more software applications that run on the OS. The processing device also may access, store, manipulate, process, and create data in response to execution of the software. For purpose of simplicity, the description of a processing device is used as singular; however, one skilled in the art will appreciated that a processing device may include multiple processing elements and multiple types of processing elements. For example, a processing device may include multiple processors or a processor and a controller. In addition, different processing configurations are possible, such a parallel processors.

Claim 1:
A method of controlling a motor driver circuit (<NUM>) of a wearable device, the method comprising:
measuring (<NUM>), via a sensor (<NUM>), a first angle of a first joint of the user;
determining (<NUM>) a resistance level to apply to the first j oint based on the first angle;
determining (<NUM>) a connection ratio between a connected time for which terminals of a motor (<NUM>) are to be electrically connected in a closed loop and a disconnected time for which the terminals of the motor (<NUM>) are to be electrically disconnected, based on the resistance level;
characterised in that,
the method further comprises the step of
controlling (<NUM>) the motor driver circuit (<NUM>) electrically connected to the motor (<NUM>) based on the connection ratio while the motor (<NUM>) is electrically disconnected from a power source.