JP5741372B2 - Walking support device and control method thereof - Google Patents

Description

  The present invention relates to a walking support device and a control method thereof.

  In recent years, the walking support device is used for rehabilitation training of a patient in which a disorder such as a paralysis symptom remains on the thigh, and is attached to the thigh. Due to the paralysis of the thigh, the patient's ability to recognize the ground contact status of the thigh and the knee bend is reduced.

  A walking support apparatus that actively supports bending and stretching of a knee during walking will land with the knee bent when the landing timing is early. When landing with the knee bent, it is impossible to output enough torque to support the patient (user), and when the weight of the user acts on the walking support device, the joint part of the walking support device May be bent and the user may lose his posture.

  By the way, in Patent Document 1, an estimated joint angle of a specific joint is obtained by substituting the detected joint angle of a sensor into another joint angle except for the angle of one specific joint in the motion equation of the articulated robot prepared in advance. A technique for calculating and determining that the feedback control of a specific joint is abnormal when the angle difference between the calculated joint angle of the specific joint and the detected joint angle is out of a predetermined allowable range is disclosed.

JP 2011-73127 A

  Although the technique of patent document 1 can detect abnormality of an articulated robot, it cannot detect abnormality of a user's gait.

  An object of the present invention is to solve such a problem, and is to provide a walking support device capable of detecting an abnormality of a user's gait and a control method thereof.

  A walking support device according to an aspect of the present invention is a walking support device that is attached to a user's thigh and supports the user's walking, the detection unit detecting the walking state of the user, Gait determination means for determining whether or not the user's gait is normal based on the free leg motion time and the free leg completion prediction time calculated based on the detection result of the detection means.

  In the above walking support device, a first link fixed to the user's upper leg, and a second link rotatably connected to the first link and fixed to the user's lower leg. And a drive means for driving the second link relative to the first link; and a control means for controlling the drive means, wherein the detection means is for the first link. First detection means for detecting a rotation angle of the second link, and second detection means for detecting a load acting on the sole of the user, wherein the gait determination means includes the first gait determination means, Predicted time calculating means for calculating the free leg completion predicted time based on the detection result of the first or second detecting means; and calculating the free leg movement time based on the detection result of the first or second detecting means. An operation time calculation means; the free leg completion prediction time; and Comparing the leg operation time, and that and a state determining means for determining whether the normal gait of the user based on the comparison result, is preferred.

  In the walking support device, the state determination unit controls the control unit to extend the user's knee when the difference between the free leg movement time and the free leg completion prediction time is 0 or less. It is preferable to operate the driving means.

  In the walking assist device, the state determination unit controls the control unit to control the drive shaft of the drive unit when an absolute value of a difference between the free leg movement time and the free leg completion predicted time is larger than a threshold value. It is preferable to operate the driving means so that a driving force proportional to the rotational angular velocity in the bending direction is expressed in the extending direction.

  The walking support apparatus further includes a warning means for calling attention to the user, and the gait determination means has an absolute value of a difference between the free leg movement time and the free leg completion predicted time larger than a threshold value. It is preferable to control the alerting means so as to alert the user.

  Preferably, the walking support device further includes a walking mode determination unit that determines whether or not the thigh on the side worn by the user is a free leg based on a detection result of the detection unit.

  A control method of a walking support device according to an aspect of the present invention is a control method of a walking support device that is attached to a user's thigh and supports the user's walking, the user's previously acquired A step of calculating a predicted free leg completion time based on the walking state, a step of calculating a free leg movement time based on the walking state of the user during walking, the predicted free leg completion time, Comparing the leg movement time, and determining whether or not the user's gait is normal based on the comparison result, and based on the determination result whether or not the user's gait is normal, And a step of controlling the driving means of the walking support device.

  In the control method of the walking support device, the driving means is operated so that the user's knee extends when the difference between the free leg movement time and the free leg completion prediction time is 0 or less. preferable.

  In the control method of the walking support device, when the absolute value of the difference between the free leg movement time and the free leg completion prediction time is greater than a threshold value, the driving force proportional to the rotational angular velocity of the drive shaft in the bending direction It is preferable to operate the driving means so that is expressed in the extending direction.

  In the control method of the walking support device, controlling the alerting means so as to alert the user when the absolute value of the difference between the swinging leg movement time and the predicted swinging leg completion time is greater than a threshold value. Are preferred.

  In the control method of the walking support device, it is preferable to further include a step of determining whether or not the thigh on the side worn by the user is a free leg.

  As described above, according to the present invention, it is possible to provide a walking support device capable of detecting an abnormality in a user's gait and a control method thereof.

It is a perspective view which shows roughly the usage type of the walking assistance apparatus which concerns on embodiment of this invention. It is a front view which shows roughly the usage pattern of the walking assistance apparatus which concerns on embodiment of this invention. It is a side view which shows roughly the usage pattern of the walk assistance apparatus which concerns on embodiment of this invention. It is a block diagram of the configuration of the control system in the walking support device according to the embodiment of the present invention. It is a block diagram of the gait determination unit. It is a flowchart figure of the control method of the walk assistance device concerning an embodiment of the invention. It is a flowchart figure of the control method of the walk assistance device concerning an embodiment of the invention. It is a flowchart figure of the control method of the walk assistance device concerning an embodiment of the invention. It is a flowchart figure of knee extension control. (A) is a figure which shows the relationship between the command torque of a drive motor, and the rotational angular velocity of a drive shaft. (B) is a figure which shows a mode that the command torque of a drive motor is applied. It is a figure which shows roughly the structure by which a user's knee is not fixed.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. However, the present invention is not limited to the following embodiment. In addition, for clarity of explanation, the following description and drawings are simplified as appropriate.

  As shown in FIGS. 1 to 3, the walking support device according to the present embodiment is worn on, for example, a user's thigh and is preferably used to support the user's walking. As shown in FIGS. 1 to 4, the walking support device 1 includes a first link 2, a second link 3, a foot placement unit 4, a knee mounting unit 5, a drive unit 6, a detection unit 7, a waist, The mounting part 8, the process part 9, and the alerting part 10 are provided.

  The first link 2 is disposed on the side of the user's upper thigh. The first links 2 of the present embodiment are respectively disposed on the left and right sides of the user's upper thigh. The upper end portion of the first link 2 is connected to the side portion of the upper leg holding portion 11. The lower end portion of the first link 2 is rotatably connected to the second link 3.

  Here, the upper thigh holding part 11 is a plate-like member, and has a curved shape so as to follow the outer peripheral shape of the user's upper thigh. The inner surface of the curved surface is brought into contact with the user's upper leg. Here, it is preferable that a buffer member such as a sponge is provided on the inner surface.

  The 2nd link 3 is arrange | positioned at the side part of the shin part in a user's lower leg part. The second links 3 of the present embodiment are respectively disposed on the left and right sides of the user's shin part. The upper end portion of the second link 3 is rotatably connected to the lower end portion of the first link 2. The lower end portion of the second link 3 is rotatably connected to the sole placement portion 4.

  The sole placement unit 4 supports the user's foot. The sole mounting part 4 of the present embodiment includes a mounting part 4a and an arm 4b. The placement portion 4a is a plate-like member on which a user's sole is placed. The arm 4 b connects the placement portion 4 a to the second link 3. That is, the arms 4b are arranged on both the left and right sides of the ankle portion of the user's lower leg.

  The upper end portion of the arm 4 b is rotatably connected to the lower end portion of the second link 3. The lower end part of the arm 4b is connected to the side part of the mounting part 4a. Thereby, the user's weight can be supported by the walking support apparatus 1.

  The knee mounting part 5 includes an arch 5a and a binding not shown. The arch 5a connects the connecting portions of the left and right first links 2 and second links 3 to each other. The binding is provided on the arch 5a. The binding fixes the arch 5a to the user's knee. The binding is not particularly limited as long as the arch 5a can be fixed to the user's knee. For example, the binding includes a band that can be attached to and detached from the user's knee.

  The driving unit 6 transmits a driving force to a connecting portion between the first link 2 and the second link 3. The drive unit 6 includes a drive motor 6a and a speed reducer 6b. The drive motor 6 a is driven based on a control signal from the control unit 92 of the processing unit 9. The driving force of the drive motor 6a is input to the speed reducer 6b.

  The speed reducer 6 b amplifies the driving force input from the driving motor 6 a and transmits the amplified driving force to the rotating shaft of the connecting portion between the first link 2 and the second link 3. As a result, the second link 3 is rotationally driven with respect to the first link 2 in the front-rear direction of the user.

  The detection unit 7 is a sensor provided in a general walking support device, and detects the walking state of the user. The detection unit 7 of the present embodiment includes an angle detection sensor 7a, a load sensor 7b, and an attitude detection sensor 7c.

  The angle detection sensor 7 a is provided at a connection portion between the first link 2 and the second link 3. The angle detection sensor 7 a detects the rotation angle of the second link 3 with respect to the first link 2 and outputs a detection signal to the processing unit 9. Here, the rotation angle of the second link 3 with respect to the first link 2 can be treated as the bending angle of the user's knee which is the user's walking state.

  The load sensor 7 b is provided on the placement portion 4 a of the sole placement portion 4. The load sensor 7 b detects a load acting on the placement unit 4 a and outputs a detection signal to the processing unit 9. Here, the load which acts on the mounting part 4a can be handled as a load which acts on the sole of the user who is in the walking state of the user.

  The posture detection sensor 7 c is stored in the storage box 8 b of the waist mounting portion 8. The attitude detection sensor 7 c detects the angle of the first link 2 with respect to the ground and outputs a detection signal to the processing unit 9. Here, the rotation angle of the first link 2 with respect to the ground can be treated as the angle of the user's upper leg with respect to the ground.

  The waist mounting portion 8 includes a belt 8a and a storage box 8b. The belt 8a is configured to be detachable from the user's waist. The storage box 8b is provided on the belt 8a. The storage box 8b stores a control board on which a battery serving as a power source for the drive motor 6a and the like, an attitude detection sensor 7c, a processing unit 9, and the like are mounted. The battery and the control board stored in the storage box 8 b are connected to the angle detection sensor 7 a and the load sensor 7 b through the wiring 12.

  The processing unit 9 includes a walking mode determination unit 91, a control unit 92, and a gait determination unit 93. The walking mode determination unit 91 determines whether the thigh on the side on which the walking support device 1 is mounted is in the standing leg state or the free leg state based on the detection signals input from the load sensor 7b and the posture detection sensor 7c. An instruction signal for instructing the walking mode is output to the control unit 92.

  That is, the walking mode determination unit 91 calculates the load acting on the user's sole based on the detection signal input from the load sensor 7b, and whether the user's sole is landed based on the calculation result. Determine whether or not.

  Further, the walking mode determination unit 91 calculates the angle of the user's upper thigh with respect to the ground based on the detection signal input from the posture detection sensor 7c, and the user's thigh is moved forward based on the calculation result. It is determined whether it is facing or facing backward.

  And the walking mode determination unit 91 is based on the determination result of whether or not the user's sole is landing and the determination result of whether the user's thigh is facing forward or backward. It is determined whether or not the thigh on the side on which the walking support device 1 is mounted is in the standing or swinging state.

  For example, when the load acting on the user's sole is equal to or greater than a preset first threshold and the user's thigh is facing backward, the walking mode determination unit 91 determines that the walking support device 1 It is determined that the thigh on the side where is attached is in a standing state. On the other hand, when the load acting on the user's sole is smaller than a preset first threshold value, the walking mode determination unit 91 is in a free leg state on the thigh on which the walking support device 1 is worn. Is determined.

  When the walking mode determination unit 91 determines that the thigh on the side on which the walking support device 1 is mounted is in the free leg state in the current walking motion, the driving motor 6a of the driving unit 6 is set in the standing mode in the next walking motion. An instruction signal is output to the control unit 92 so as to be controlled. On the other hand, when the walking mode determination unit 91 determines that the thigh on the side on which the walking support device 1 is attached is in the standing state in the current walking motion, the walking mode determination unit 91 plays the drive motor 6a of the driving unit 6 in the next walking motion. An instruction signal is output to the control unit 92 so as to control in the leg mode.

  The control unit 92 generates a detection signal from the angle detection sensor 7a and the load sensor 7b, an instruction signal from the walking mode determination unit 91, and a signal indicating that the free leg operation from the gait determination unit 93 is completed as will be described later. Based on this, the drive motor 6a of the drive unit 6 is controlled.

  That is, when an instruction signal indicating that the drive motor 6a is to be controlled in the stance mode is input from the walking mode determination unit 91, the control unit 92 receives a signal indicating that the free leg motion has been completed from the gait determination unit 93. If the thigh on the side on which the walking support device 1 is worn and the thigh on the opposite side are in the free leg state, the weight of the user is determined by the walking support device 1. The drive motor 6a is controlled so that the motor can be supported.

  On the other hand, when an instruction signal indicating that the drive motor 6a is to be controlled in the swing leg mode is input from the walking mode determination unit 91, the control unit 92 at least moves the thigh on the side on which the walking support device 1 was previously mounted. Based on the detection signals acquired from the angle detection sensor 7a, the load sensor 7b, and the posture detection sensor 7c when the leg is in the leg state, the thigh on the side where the walking support device 1 is mounted in the next walking motion is in the free leg state. The user's stride, walking speed, walking trajectory, and the like are calculated predictively.

  In other words, the control unit 92 determines the knee of the user based on the detection signal input from the angle detection sensor 7a when at least the thigh on the side on which the walking support device 1 was previously mounted is in the free leg state. The bending angle is calculated.

  In addition, the control unit 92 determines that the sole of the user's sole is based on the detection signal input from the load sensor 7b when the thigh on the side on which the walking support device 1 was previously mounted is in the free leg state. Calculate the landing time.

  Furthermore, the control unit 92 determines whether the user is large with respect to the ground based on a detection signal input from the posture detection sensor 7c when the thigh on the side where the walking support device 1 is mounted last becomes a free leg state. Calculate the thigh angle.

  Based on these pieces of information, the control unit 92 calculates the user's stride using, for example, forward kinematics, and calculates the user's walking speed based on the step and the time when the user's sole landed. . Furthermore, the control unit 92 calculates the relationship (walking trajectory) between time and the knee angle of the user for realizing the calculated walking speed. Based on the calculated user's walking trajectory and the like, the control unit 92 determines the user's stride and walking speed when the thigh on the side on which the walking support device 1 is mounted is in a free leg state in the next walking motion. The walking trajectory is calculated predictively. That is, the control unit 92 realizes the next walking motion so as to follow the user's stride, walking speed, walking trajectory, and the like calculated based on the previous walking motion.

  The control unit 92 generates a control signal for the drive motor 6a of the drive unit 6 so that the user's step length, walking speed, walking trajectory, and the like calculated in a predictive manner are realized, and the drive motor is based on the control signal. 6a is controlled. On the other hand, the control unit 92 outputs the user's stride, walking speed, walking trajectory, and the like calculated predictively to the gait determination unit 93.

  Here, the control unit 92 also controls the drive motor 6 a of the drive unit 6 based on the determination result of the gait determination unit 93. As shown in FIG. 5, the gait determination unit 93 includes a predicted time calculation unit 93a, an operation time calculation unit 93b, and a state determination unit 93c.

  The predicted time calculation unit 93a is equipped with the walking support device 1 that is in a swinging state based on the user's predicted step length, walking speed, walking trajectory, and the like input from the control unit 92. The predicted free leg completion time when the soles of the thighs on the landing side land is calculated. The predicted time calculation unit 93a outputs an output signal indicating the calculated free leg completion predicted time to the state determination unit 93c.

The movement time calculation unit 93b calculates the free leg movement time or the free leg completion time . That is, the operation time calculation unit 93b is based on the detection signals from the load sensor 7b and the posture detection sensor 7c, and the soles of the thighs on the side on which the walking support device 1 is worn are separated from the ground. The time is calculated (measured) intermittently until it reaches the ground again. The movement time calculation unit 93b outputs an output signal indicating the calculated free leg movement time or free leg completion time to the state determination unit 93c.

The state determination unit 93c determines whether or not the walking motion is completed based on the detection signal input from the angle detection sensor 7a or the load sensor 7b, or inputs from the predicted time calculation unit 93a and the operation time calculation unit 93b. Based on the signal, the free leg completion prediction time and the free leg movement time , or the free leg completion prediction time and the free leg completion time are compared, and an instruction signal is output to the control unit 92 based on the comparison result, Control the alerting unit 10.

  The alerting unit 10 alerts the user based on the instruction signal input from the state determining unit 93c. The alerting unit 10 may be configured to alert the user by sight, hearing, touch, or the like. For example, the alerting unit 10 includes a speaker or the like, and the speaker operates based on an instruction signal input from the state determination unit 93c. The alerting part 10 is provided in the waist mounting part 8, for example. However, the installation position is not particularly limited as long as it is provided at a position where the user can recognize the alert from the alerting unit 10.

  The walking support device having such a configuration operates as shown in FIGS. However, in the following description, the operation when the thigh on the side on which the walking support device is mounted is changed from the standing state to the free leg state, particularly the operation based on the gait of the user will be described in detail.

  First, the angle detection sensor 7a detects the flexion angle of the user's knee and outputs a detection signal to the control unit 92 and the gait determination unit 93 (S1). At the same time, the load sensor 7b detects a load acting on the sole of the user and outputs a detection signal to the walking mode determination unit 91, the control unit 92, and the gait determination unit 93. The posture detection sensor 7c detects the angle of the user's upper leg with respect to the ground, and outputs a detection signal to the walking mode determination unit 91, the control unit 92, and the gait determination unit 93.

  Next, the walking mode determination unit 91 calculates the load acting on the sole of the user based on the detection signals input from the load sensor 7b and the posture detection sensor 7c, and the angle of the user's upper thigh Is calculated (S2).

  Here, in the present embodiment, since it is assumed that the thigh on the side where the walking support device 1 is mounted changes from the standing state to the free leg state, the walking support device 1 is mounted in the step S2. The load on the sole of the user and the angle of the upper thigh are calculated.

  Next, the walking mode determination unit 91 determines whether the thigh on the side on which the walking assistance device 1 is mounted is in the standing leg state or the free leg state based on these pieces of information (S3). Here, as described above, since it is assumed that the thigh on the side where the walking support device 1 is mounted is in the swinging state, the walking mode determination unit 91 determines that the walking support device 1 is in the next walking motion. It is determined that the attached thigh is in a free leg state, and an instruction signal to control the drive motor 6a in the free leg mode is output to the control unit 92 in the next walking motion.

  Next, when an instruction signal indicating that the drive motor 6a is to be controlled in the swing leg mode is input from the walking mode determination unit 91, the control unit 92 at least detects the thigh on the side on which the walking support device 1 was previously mounted. Based on the user's stride, walking speed, walking trajectory, etc. when the leg is in the swinging leg state, the thigh on the side where the walking support device 1 is worn becomes the swinging leg state in the next walking motion. The user's stride, walking speed, walking trajectory, and the like are calculated predictively (S4). Then, the control unit 92 outputs the user's stride, walking speed, walking trajectory, and the like calculated predictively to the predicted time calculation unit 93 a of the gait determination unit 93.

  Next, based on the user's stride, walking speed, walking trajectory, and the like calculated predictively, the predicted time calculation unit 93a lands the sole of the thigh on which the walking support device 1 is worn on the ground. A predicted free leg completion time is calculated (S5). Then, the predicted time calculating unit 93a outputs an output signal indicating the calculated free leg completion predicted time to the state determining unit 93c.

  Next, the control unit 92 generates a control signal for the drive motor 6a of the drive unit 6 and drives the control signal so that the user's step length, walking speed, walking locus, and the like calculated predictively are realized. Output to the motor 6a (S6).

The drive motor 6a is controlled based on the control signal. At this time, the angle detection sensor 7a detects the bending angle of the user's knee and outputs a detection signal to the control unit 92 and the gait determination unit 93 (S7). At the same time, the load sensor 7b detects a load acting on the sole of the user and outputs a detection signal to the walking mode determination unit 91, the control unit 92, and the gait determination unit 93. The posture detection sensor 7c detects the angle of the user's upper leg with respect to the ground, and outputs a detection signal to the walking mode determination unit 91, the control unit 92, and the gait determination unit 93. Further, gait operation time calculation unit 93b of the judging unit 93 starts calculating the swing operating time or swing completion time, outputs an output signal indicative of the swing operation time or swing completion time to the state determination unit 93c To do.

  Next, the state determination unit 93c determines whether or not the walking motion is completed based on the detection signal input from the angle detection sensor 7a or the load sensor 7b (S8). For example, the state determination unit 93c calculates the bending angle of the user's knee based on the detection signal input from the angle detection sensor 7a and compares it with a preset second threshold, and the comparison result is the second. If it is smaller than the threshold value, it is determined that the user's sole is in a landing state and the walking motion is completed. Or the state determination part 93c calculates the load which acts on a user's sole based on the detection signal input from the load sensor 7b, compares with the preset 3rd threshold value, and a comparison result is the 1st. When the threshold value is larger than 3, it is determined that the user's sole is in a landing state and the walking motion is completed. However, the method for determining whether or not the walking motion is completed is not limited to these.

When the state determination unit 93c determines that the walking motion has not yet been completed (NO in S8), based on the signals input from the predicted time calculation unit 93a and the motion time calculation unit 93b, the free leg completion predicted time, The free leg movement time is compared (S9). Here, the state determination unit 93c determines whether or not a value obtained by subtracting the free leg completion predicted time from the free leg movement time is larger than the fourth threshold value.

If the state determination unit 93c determines that the value obtained by subtracting the predicted free leg completion time from the free leg movement time is equal to or less than the fourth threshold value (NO in S9), the step of controlling the drive motor 6a based on the control signal Return to (S6). If such a determination result is derived, it can be estimated that the normal walking motion is still in progress, and therefore the control of the drive motor 6a is continued.

On the other hand, if the state determination unit 93c determines that the value obtained by subtracting the free leg completion predicted time from the free leg movement time is larger than the fourth threshold value (YES in S9), the state alert unit 93c alerts the user to call attention. An instruction signal is output to the unit 10 (S10). The alerting unit 10 operates so as to stimulate one of the five senses such as vision, hearing, and touch to the user based on the instruction signal. If this determination result is derived, even beyond Yu Ashikan completion prediction time, a state in which the sole of the user is not landed, some abnormality has occurred (e.g., the user posture Alert the user to the user. Thereby, the user can easily recognize that the walking motion and the assisting motion of the walking assist device 1 are not synchronized.

  And the state determination part 93c outputs an instruction | indication signal to the control part 92 so that the driving force proportional to the rotational angular velocity of the bending direction of the drive shaft of the drive motor 6a may be expressed from the said drive motor 6a in the extending direction. The control unit 92 generates a control signal for the drive motor 6a such that the drive motor 6a develops in the extension direction a drive force proportional to the rotational angular velocity of the drive shaft of the drive motor 6a in the bending direction, and based on the control signal. Then, the drive motor 6a is controlled (S11).

That is, if the walking motion is not yet completed and the free leg completion time is uncertain, and the value obtained by subtracting the predicted free leg completion time from the free leg motion time is larger than the fourth threshold, It is very likely that something is wrong. At this time, there is a possibility that the drive motor 6a operates intermittently to extend the user's knee. For example, even if a user who has lost his / her posture tries to bend the knee, the drive force of the drive motor 6a May be hindered.

  Therefore, as shown in FIGS. 10A and 10B, the control unit 92 drives the drive motor so that a drive force proportional to the rotational angular velocity in the bending direction of the drive shaft of the drive motor 6a is expressed in the extending direction. 6a is controlled. Thereby, when a rotational angular velocity is generated in the knee flexion direction, torque is generated in the knee extension direction according to the rotational angular velocity. Therefore, when the user slowly bends the knee, the user does not feel the resistance due to the driving force of the driving motor 6a. Therefore, the user can easily bend the knee when an unexpected situation occurs.

  Incidentally, in the graph of FIG. 10A, the user's knee is bent as the rotation direction of the drive shaft of the drive motor 6a goes in the minus direction.

  In this embodiment, as shown in FIG. 10A, the drive shaft of the drive motor 6a is a dead zone from 0 rad / s to a predetermined angular velocity, and the drive force of the drive motor 6a is not expressed. Therefore, the user can bend more easily from the state where the knee is extended.

When the state determination unit 93c determines that the walking motion is complete (YES in S8), the state determination unit 93c outputs a signal indicating that the walking motion is complete to the motion time calculation unit 93b. The motion time calculation unit 93b determines the free leg completion time based on the signal (S12).

Next, the state determination unit 93c determines whether or not the absolute value of the difference between the determined free leg completion time and the free leg completion predicted time is greater than the fifth threshold (S13). When the state determination unit 93c determines that the absolute value of the difference between the determined free leg completion time and the predicted free leg completion time is smaller than the fifth threshold (NO in S13), the current walking operation is completed and the next time Transition to walking motion. When such a determination result is derived, it can be estimated that the walking motion has been normally completed, and therefore a signal indicating that the free leg motion has been completed is output to the control unit 92.

On the other hand, if the state determination unit 93c determines that the absolute value of the difference between the determined free leg completion time and the predicted free leg completion time is greater than the fifth threshold (YES in S13), the free leg completion is performed from the free leg completion time. It is determined whether or not the value obtained by subtracting the prediction time is greater than 0 (S14). If the state determination unit 93c determines that the value obtained by subtracting the free leg completion predicted time from the free leg completion time is 0 or less (NO in S14), the state determination unit 93c sends an instruction signal to the control unit 92 so that the user's knee extends. Output. The controller 92 controls the drive motor 6a based on the instruction signal (S15). When such a determination result is derived, it can be estimated that the sole of the foot has landed while the user's knee is bent, so the drive motor 6a is controlled so that the user's knee extends.

Specifically, the process of S15 for controlling the drive motor 6a so that the user's knee extends is executed according to the flow shown in FIG.
First, when the command signal is input, the control unit 92 sets a target rotation angle of the second link 3 relative to the first link 2 so that the user's knee extends (S151). That is, when the command signal is input, the control unit 92 reads, for example, a preset target rotation angle of the second link 3 with respect to the first link 2 and sets the target rotation angle.

  Next, the control unit 92 calculates the current rotation angle of the second link 3 with respect to the first link 2 based on the detection signal of the angle detection sensor 7a (S152).

  Next, the controller 92 drives the drive motor based on the current rotation angle of the second link 3 with respect to the first link 2 and the target rotation angle of the second link 3 with respect to the set first link 2. A control signal 6a is generated (S153), and the drive motor 6a is controlled based on the control signal (S154).

Thereafter, returning to the flow of FIG. 8, the state determination unit 93c subtracts the rotation angle of the second link 3 relative to the current first link 2 from the target rotation angle based on the detection signal of the angle detection sensor 7a . It is determined whether or not the value is smaller than a sixth threshold value (S16). When the state determination unit 93c determines that the value obtained by subtracting the current rotation angle of the second link 3 relative to the first link 2 from the target rotation angle is smaller than the sixth threshold value (YES in S16), the swing leg motion is performed. A signal indicating completion is output to the control unit 92.

  In this way, even if the soles land before the user's knee extends, the driving force is developed to extend the user's knee, so the user's walking becomes unstable. Can be prevented.

On the other hand, when the state determination unit 93c determines that the value obtained by subtracting the current rotation angle of the second link 3 with respect to the first link 2 from the target rotation angle is greater than or equal to the sixth threshold (NO in S16), It is determined whether or not a value obtained by subtracting the free leg completion time from the predicted leg completion time is greater than a seventh threshold value (S17).

State determining unit 93c includes a value obtained by subtracting the free leg completion time from swing completion prediction time is less than the seventh threshold value (NO in S17), and controls the drive motor 6a so as to extend the knee of a user Return to step (S15). If such a determination result is derived, it can be estimated that the user's sole has landed slightly earlier and the knee extension control is still insufficient, so the user's knee extends. Thus, the drive motor 6a is continuously controlled.

On the other hand, the state determining unit 93c is, (YES S17) of the swing completion prediction time and a value obtained by subtracting the free leg completion time is greater than the seventh threshold value, proportional to the rotational angular velocity of the bending direction of the drive shaft of the drive motor 6a An instruction signal is output to the control unit 92 so that the driving motor 6a develops the driving force to be generated in the extending direction. The control unit 92 generates a control signal for the drive motor 6a so that a drive force proportional to the rotational angular velocity in the bending direction of the drive shaft of the drive motor 6a is expressed from the drive motor 6a in the extending direction. Based on this, the drive motor 6a is controlled (S18). If such a determination result is derived, the difference between the free leg completion time and the predicted free leg completion time is large, and it is assumed that there is some abnormality just by landing the user's sole for the time being. Can do. In this case, since the drive motor 6a continues to operate to extend the user's knee, there is a possibility that the user's knee is fixed. Therefore, the control unit 92 controls the drive motor 6a so that a drive force proportional to the rotational angular velocity in the bending direction of the drive shaft of the drive motor 6a is expressed in the extending direction. As a result, the user can easily bend the knee without substantially feeling the resistance due to the driving force of the drive motor 6a.

When the state determination unit 93c determines that the value obtained by subtracting the free leg completion predicted time from the free leg completion time is greater than 0 (YES in S14), the state determination unit 93c instructs the attention calling unit 10 to alert the user. Is output (S19). The alerting unit 10 operates so as to stimulate one of the five senses such as vision, hearing, and touch to the user based on the instruction signal. If such a determination result is derived, the user's feet are landed for the time being, and some abnormality may have occurred, so the user is alerted. Thereby, the user can easily recognize that the walking motion and the assisting motion of the walking assist device 1 are not synchronized.

Further, the state determination unit 93c determines whether or not a value obtained by subtracting the predicted free leg completion time from the free leg completion time is greater than an eighth threshold (S20). State determining unit 93c determines that the value obtained by subtracting the free leg completion prediction time from the swing completion time is less than an eighth threshold value (NO in S20), the next walking motion to complete the current walking Transition. If such a determination result is derived, it can be estimated that the sole of the foot has landed on the ground while the user's knees are extended, although it takes a long time to complete the free leg. Is output to the control unit 92.

On the other hand, the state determining unit 93c determines that the value obtained by subtracting the free leg completion prediction time from the swing completion time greater than a threshold value of the 8 (S20 of YES), the rotation angular velocity of the bending direction of the drive shaft of the drive motor 6a An instruction signal is output to the control unit 92 so that the drive motor 6a develops a drive force proportional to The control unit 92 generates a control signal for the drive motor 6a so that the drive force proportional to the rotational angular velocity in the bending direction of the drive shaft of the drive motor 6a appears in the extending direction, and the control signal is generated as the control signal. Based on this, the drive motor 6a is controlled (S21). If such a determination result is derived, the difference between the free leg completion time and the predicted free leg completion time is large, and it is assumed that there is some abnormality just by landing the user's sole for the time being. Can do. In this case, since the drive motor 6a continues to operate to extend the user's knee, there is a possibility that the user's knee is fixed. Therefore, the control unit 92 controls the drive motor 6a so that a drive force proportional to the rotational angular velocity in the bending direction of the drive shaft of the drive motor 6a is expressed in the extending direction. Accordingly, the user can bend the knee without substantially feeling the resistance due to the driving force of the driving motor 6a.

The walking support device and the control method thereof according to the present embodiment determine the user's gait based on the free leg movement time , the free leg completion time, and the free leg completion prediction time. Based on the determination result, the drive motor is controlled. Therefore, even if the user's gait is disturbed, the user's gait can be stabilized or the gait can be appropriately restored.

  In addition, based on the user's stride, walking speed, walking trajectory, and the like at the previous walking motion, the user's stride, walking speed, walking trajectory, etc. at the next walking motion are predicted. Therefore, walking support that always reflects the walking state of the user can be performed.

As mentioned above, although embodiment of the walk assistance device and its control method concerning the present invention was described, it is not restricted to the above but can be changed in the range which does not deviate from the technical idea of the present invention.
For example, in the above-described embodiment, the driving motor 6a is driven so that a driving force proportional to the rotational angular velocity in the bending direction of the driving shaft of the driving motor 6a is expressed in the extending direction, whereby the user's knee is extended. However, this is not the case. That is, as shown in FIG. 11, for example, the first link 2 may be configured to include an elastic body 13 whose repulsive force increases as the first link 2 approaches the extended state, and the extended state of the user's knee may not be fixed. . With such a configuration, it is possible to easily realize a configuration in which the extended state of the user's knee is not fixed. For example, by providing a fixing jig at the upper end of the second link 3 and disposing the elastic body 13 between the fixing jig and the first link 2, the first link becomes closer as the knee approaches the extended state. A repulsive force can be applied to 2. Of course, the installation method of the elastic body 13 is not limited to this.

For example, in the above embodiment, the user is not alerted at the time of knee extension control, but it is preferable to alert the user also at the time of knee extension control.
For example, in the above embodiment, the control method is executed using hardware resources, but the control method may be executed using software resources.

DESCRIPTION OF SYMBOLS 1 Walking assistance apparatus 2 1st link 3 2nd link 4 Foot mounting part, 4a mounting part, 4b arm 5 knee mounting part, 5a arch 6 drive part, 6a drive motor, 6b reduction gear 7 detection part, 7a Angle detection sensor, 7b Load sensor, 7c Posture detection sensor 8 Waist wearing part, 8a Belt, 8b Storage box 9 Processing part 91 Walking mode determination part 92 Control part 93 Gait determination part, 93a Predictive time calculation part, 93b Operating time Calculation part, 93c State determination part 10 Alerting part 11 Upper leg holding part 12 Wiring 13 Elastic body

Claims (16)

A walking support device that is mounted on a user's thigh and supports the user's walking,
Detecting means for detecting a walking state of the user;
Calculated based on the detection result of the detection means , a free leg movement time and a free leg completion prediction time which are intermittently calculated from the start to completion of the free leg state in the leg of the user, Alternatively, it is determined whether or not the gait of the user is normal based on a free leg completion time which is a time from the start to the completion of the free leg state in the user's leg and the predicted free leg completion time. Gait judging means,
A walking support device comprising: A first link fixed to the upper leg of the user;
A second link rotatably connected to the first link and secured to the user's lower leg;
Drive means for driving the second link relative to the first link;
Control means for controlling the drive means;
Further comprising
The detection means includes
First detection means for detecting a rotation angle of the second link with respect to the first link;
Second detection means for detecting a load acting on the sole of the user;
With
The gait determination means includes:
Predicted time calculation means for calculating the free leg completion predicted time based on the detection result of the first or second detection means;
Motion time calculating means for calculating the swing leg motion time or the swing leg completion time based on the detection result of the first or second detection means;
The free leg completion predicted time and the free leg movement time , or the free leg completion predicted time and the free leg completion time are compared, and it is determined whether or not the gait of the user is normal based on the comparison result. State determination means;
The walking support device according to claim 1, comprising: The state determination means is configured such that an absolute value of a difference between the free leg completion time and the free leg completion predicted time is larger than a threshold for determining whether or not the walking motion is normally completed, and the free leg is completed. If the value obtained by subtracting the predicted free leg completion time from time is 0 or less, it is determined that the sole has landed with the user's knee bent, and the control means is controlled to control the user's knee. The walking support apparatus according to claim 2, wherein the driving means is operated so that the extension extends. Said state determining means, a value obtained by subtracting the free leg completion prediction time from the swing operating time, larger than the threshold for determining whether the user is breaking the posture, the user posture The driving means is operated so that a driving force proportional to a rotational angular velocity in a bending direction of a driving shaft of the driving means is expressed in the extending direction by determining that the motor is broken. 2. The walking support device according to 2.   If the value obtained by subtracting the free leg completion time from the predicted free leg completion time is greater than a threshold value for determining whether or not the user has lost his / her posture, the state determination means The driving means is operated so that a driving force proportional to a rotational angular velocity in a bending direction of a driving shaft of the driving means is expressed in the extending direction by determining that the motor is broken. 2. The walking support device according to 2.   When the value obtained by subtracting the predicted free leg completion time from the free leg completion time is greater than a threshold for determining whether or not the user has lost his / her posture, the state determination means The driving means is operated so that a driving force proportional to a rotational angular velocity in a bending direction of a driving shaft of the driving means is expressed in the extending direction by determining that the motor is broken. 2. The walking support device according to 2. A warning means for calling attention to the user;
Said state determining means, a value obtained by subtracting the free leg completion prediction time from the swing operating time, larger than the threshold for determining whether the user is breaking the posture, the user posture It determines that the are break, walking assist apparatus according to any one of claims 2 to 6 for controlling said alerting means to call attention to the user.   A warning means for calling attention to the user;
  The state determination means is configured such that an absolute value of a difference between the free leg completion time and the free leg completion predicted time is larger than a threshold for determining whether or not the walking motion is normally completed, and the free leg is completed. When the value obtained by subtracting the predicted free leg completion time from time is greater than 0, it is determined that the user has lost his / her posture, and the alerting means is controlled to alert the user. The walking support device according to any one of 2 to 6. According to any one of claims 1 to 8 further comprising a walking mode determining means for determining whether leg free leg side mounted on the user based on a detection result of said detecting means Walking support device. A method for controlling a walking support device that is mounted on a user's thigh and supports the user's walking,
A step of calculating a free leg completion prediction time based on the user's previously acquired walking state;
Based on the walking state of the user during walking, the free leg movement time that is intermittently calculated from the start to completion of the free leg state in the leg of the user, or the user's Calculating a free leg completion time which is a time from the start to the completion of the free leg state in the leg ;
The free leg completion predicted time and the free leg movement time , or the free leg completion predicted time and the free leg completion time are compared, and it is determined whether or not the gait of the user is normal based on the comparison result. Process,
A step of controlling the driving means of the walking support device based on the determination result of whether or not the gait of the user is normal;
A control method for a walking support device. The absolute value of the difference between the free leg completion time and the predicted free leg completion time is greater than a threshold for determining whether or not the walking motion has been normally completed, and the free leg is completed from the free leg completion time. When the value obtained by subtracting the predicted time is 0 or less, it is determined that the sole of the foot has landed while the user's knee is bent, and the driving means is operated so that the user's knee extends. the method of the walking assistance device according to 10. If the value obtained by subtracting the predicted free leg completion time from the free leg movement time is greater than a threshold value for determining whether or not the user has lost posture, it is determined that the user has lost posture. The method of controlling a walking support apparatus according to claim 10 , wherein the driving unit is operated so that a driving force proportional to a rotational angular velocity in a bending direction of the driving shaft of the driving unit is developed in the extending direction.   If the value obtained by subtracting the free leg completion time from the predicted free leg completion time is greater than a threshold value for determining whether or not the user has lost posture, it is determined that the user has lost posture. The method of controlling a walking support apparatus according to claim 10, wherein the driving unit is operated so that a driving force proportional to a rotational angular velocity in a bending direction of the driving shaft of the driving unit is developed in the extending direction.   If the value obtained by subtracting the predicted free leg completion time from the free leg completion time is larger than a threshold for determining whether or not the user has lost his / her posture, it is determined that the user has lost his / her posture. The method of controlling a walking support apparatus according to claim 10, wherein the driving unit is operated so that a driving force proportional to a rotational angular velocity in a bending direction of the driving shaft of the driving unit is developed in the extending direction. If the value obtained by subtracting the predicted free leg completion time from the free leg movement time is greater than a threshold value for determining whether or not the user has lost posture, it is determined that the user has lost posture. And the control method of the walk assistance apparatus of any one of Claims 10 thru | or 14 which controls an alerting means so as to alert the said user. The absolute value of the difference between the free leg completion time and the predicted free leg completion time is greater than a threshold for determining whether or not the walking motion has been normally completed, and the free leg is completed from the free leg completion time. If greater than the value obtained by subtracting the prediction time is zero, determines that the user is breaking the posture, any one of claims 10 to 14 for controlling the alerting means to call attention to the user 1 A control method for the walking support device according to claim.

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