JP5477064B2 - Walking assist device - Google Patents

Description

  The present invention relates to a walking assist device that assists a user's walking motion. In particular, the present invention relates to a walking assist device suitable for rehabilitation of walking motion.

  Devices that assist the user's walking movement have been developed. For example, Patent Literature 1 discloses a wearable walking assist device that includes an actuator that applies torque to a user's hip joint and knee joint.

Japanese Patent Laid-Open No. 2005-23003

  The walking assist device of Patent Document 1 is made for the purpose of assisting the work of carrying a heavy object, and is a type called a so-called powered suit. The technique of Patent Document 1 is considered to be applicable to a rehabilitation device for a non-healthy person who cannot smoothly move one leg, for example.

  When it is assumed that the technology of Patent Document 1 is applied to a rehabilitation device, particularly when it is assumed to be applied to a rehabilitation device for a severely unhealthy person, it is necessary to consider the following two points: There is. One is that it is preferable to apply torque not only to the knee joint but also to the ankle joint in order to assist the walking motion to be smooth. The other is that as the rehabilitation effect increases and the walking motion of the unhealthy person becomes smooth, it is preferable to eliminate the knee joint assistance and assist the ankle joint for rehabilitation. An object of the present invention is to provide a walking assistance device that meets such demands.

The walking assistance device according to the present invention is attached to a non-healthy leg of a user whose one leg is a non-healthy leg. This walking assist device has a knee brace, a short leg brace, and a cord . The knee brace is configured to be worn from the upper leg to the lower leg of the user, and has an actuator that applies torque to the knee joint. The short leg brace is configured to be worn from the user's lower leg to the foot, and has an actuator that applies torque to the ankle joint. The cord can electrically connect the knee brace and the short leg brace. The knee brace can be separated from the short leg brace by removing the cord .

In this walking assist device, torque can be applied to the knee joint by the knee brace, and torque can be applied to the ankle joint by the short leg brace. As a result, it is possible to more smoothly assist the walking motion of a severe non-healthy person. In addition, since the knee brace and the short leg brace are separable, the short leg brace can be worn without wearing the knee brace when the walking motion is smooth due to rehabilitation. Thereby, walking assistance can be performed by assisting the ankle joint without assisting the knee joint.

Above the walking assist device, that further comprise a controller for controlling the actuator of the actuator and the short leg brace knee brace. Also, the knee brace has an attitude angle sensor for detecting the inclination angle of the upper leg, the short leg orthosis, that has a ground sensor which detects that the foot has contact with the floor. Furthermore, the controller controls the knee brace actuator and the short leg brace actuator using the sensor data of the posture angle sensor and the ground sensor, and the sensor data of the ground sensor without using the sensor data of the posture angle sensor. that is configured to switch the independent control mode for controlling the actuator of the ankle-foot orthosis with.
In addition, it is preferable that a controller performs control so that a user's walk may be assisted. In the coordinated control mode, when the condition that the ground sensor is off and the posture angle sensor detects that the upper thigh is swung forward is satisfied, the knee brace actuator and the short leg brace actuator are When the angle is controlled and the above condition is not satisfied, it is preferable that the knee brace actuator is angle-controlled and the short leg brace actuator is torque-controlled. In the independent control mode, the angle of the actuator of the short leg brace is preferably controlled when the ground sensor is off, and the actuator of the short leg brace is torque controlled when the ground sensor is on.

  According to such a configuration, when the knee brace and the short leg brace are worn, the knee brace actuator and the short leg brace actuator are controlled using the sensor data of the posture angle sensor and the sensor data of the ground sensor. be able to. When the short leg brace is worn without wearing the knee brace, the actuator of the short leg brace can be controlled using the sensor data of the ground sensor without using the sensor data of the posture angle sensor. Whether the knee brace and the short leg brace are worn or the short leg brace is worn without the knee brace, the controller can appropriately control the actuator.

  ADVANTAGE OF THE INVENTION According to this invention, the walk assistance apparatus which can be used for the walk assistance which assists a knee joint and an ankle joint, and can also be used for the walk assistance which assists an ankle joint without assisting a knee joint is realized. Can do.

FIG. 3 is a front view of a user wearing the walking assist device 10 including the knee brace 30. FIG. 3 is a side view of a user wearing the walking assistance device 10 including the knee brace 30. FIG. 3 is a side view of a user wearing the walking assistance device 10 excluding the knee brace 30. The flowchart which shows the process prescribed | regulated by the cooperative control program. The flowchart which shows the process prescribed | regulated by the independent control program.

  The walking assistance device according to the embodiment will be described. 1 and 2 show a schematic configuration of the walking assist device 10 in a state worn by a user. As shown in FIGS. 1 and 2, the walking assistance device 10 includes a box 20, a knee brace 30, and a short leg brace 50. The box 20, the knee brace 30, and the short leg brace 50 are configured separately. The box 20 is worn on the user's waist. The knee brace 30 and the short leg brace 50 are worn on the user's non-healthy legs. The walking assist device 10 can be used with the box 20, the knee brace 30 and the short leg brace 50 attached as shown in FIGS. 1 and 2, while the knee brace 30 is used as shown in FIG. Without wearing, only the box 20 and the short leg brace 50 can be worn and used.

  As shown in FIGS. 1 and 2, the box 20 is attached to the user's waist. The box 20 contains a battery and a controller. Box 20 is connected to knee brace 30 by cord 42. The knee brace 30 is connected to the short leg brace 50 by a cord 44. The cords 42 and 44 are connected to the connection target by a connector and can be detached from the connection target. The codes 42 and 44 have a power supply line and an analog data line. The battery built in the box 20 supplies power to the knee brace 30 and the short leg brace 50 via the power supply lines of the cords 42 and 44. The controller contained in the box 20 communicates with the knee brace 30 and the short leg brace 50 via the analog data lines of the cords 42, 44. As shown in FIG. 3, the walking assistance device 10 can be used by wearing only the box 20 and the short leg brace 50 without wearing the knee brace 30. In this case, the box 20 is connected to the short leg brace 50 by the cord 46. The controller stores a cooperative control program executed when the knee brace 30 is worn, and an independent control program executed when the knee brace 30 is not worn. The box 20 is provided with operation switches and the like.

  The knee brace 30 assists the movement of the user's knee joint. The knee brace 30 has an upper leg fixing part 32 and a lower leg fixing part 34. The upper thigh fixing part 32 is fixed (mounted) to the user's upper thigh. The crus fixing part 34 is fixed (mounted) to the user's crus (under the knee). The crus fixing part 34 is connected to the crus fixing part 32 at the knee joint part 36. The crus fixing part 34 can rotate with respect to the crus fixing part 32 about the knee joint part 36 as an axis. The knee brace 30 is mounted at a position where the knee joint 36 can rotate coaxially with the user's knee joint. A motor 38 is installed at the knee joint 36. The motor 38 is a servo motor with a built-in encoder. A control command value is input to the motor 38 from the controller. The motor 38 rotates the lower leg fixing part 34 relative to the upper leg fixing part 32 in accordance with the input control command value. A posture angle sensor 40 is installed in the upper leg fixing portion 32. The posture angle sensor 40 detects the posture angle (inclination angle with respect to the vertical direction) of the upper leg fixing portion 32 around the pitch axis. The posture angle sensor 40 detects the posture angle with the direction indicated by the arrow 90 in FIG. The attitude angle detected by the attitude angle sensor 40 is input to the controller.

  The short leg brace 50 assists the movement of the user's ankle joint. The short leg brace 50 includes a crus fixing part 52 and a foot fixing part 54. The lower leg fixing part 52 is fixed (mounted) on the user's lower leg (on the ankle). The foot fixing unit 54 is fixed (mounted) to the user's foot. The foot fixing part 54 is connected to the crus fixing part 52 at the ankle joint part 56. The foot fixing portion 54 can rotate with respect to the crus fixing portion 52 about the ankle joint portion 56. The short leg brace 50 is mounted at a position where the ankle joint 56 can rotate coaxially with the user's ankle joint. A motor 58 is installed at the ankle joint 56. The motor 58 is a servo motor with a built-in encoder. A control command value is input to the motor 58 from the controller. The motor 58 rotates the foot fixing part 54 with respect to the crus fixing part 52 in accordance with the input control command value. Three ground sensors 55 a to 55 c are installed on the bottom of the foot fixing portion 54. The ground sensor 55a is installed at a position corresponding to the user's eyelid. The ground sensor 55b is installed at a position corresponding to the user's thumb ball (base of the thumb). The ground sensor 55c is installed at a position corresponding to the user's toe. The ground sensors 55a to 55c are turned on when a corresponding portion of the bottom of the foot fixing portion 54 is grounded, and are turned off when not grounded. That is, the ground sensors 55a to 55c output on / off signals. The output on-off signal is input to the controller.

  Next, sensor data output by each sensor during walking will be described. When the knee brace 30 is worn, the posture angle sensor 40 periodically outputs the posture angle of the upper leg of the unhealthy leg. Further, in a state where the entire sole of the non-healthy leg is grounded (for example, the state of FIG. 2), all the three ground sensors 55a to 55c are turned on. If a healthy leg (a leg not equipped with the walking assist device 10) is stepped on from this state, the heel of the non-healthy leg floats. Accordingly, the ground contact sensor 55a is turned off. Thereafter, when the non-healthy leg is stepped on, the non-healthy leg leaves in the order of the thumb ball and the toes. Accordingly, the thumb ball grounding sensor 55b is turned off first, and then the toe grounding sensor 55c is turned off. The non-healthy leg that has become a swing leg is swung forward. Therefore, the posture angle of the upper leg of the unhealthy leg (that is, the posture angle detected by the posture angle sensor 40) increases. When the swinging of the non-healthy leg forward is completed, the non-healthy leg is moved so as to come in contact with the heel. During this operation (from the end of swinging the non-healthy leg forward until the non-healthy leg heel contacts the ground), the posture angle of the upper leg of the non-healthy leg (that is, the posture angle sensor 40 is The detected attitude angle) decreases. When the heel of the unhealthy leg touches down, the heel ground sensor 55a is turned on. Thereafter, the weight of the user moves to the non-healthy leg side, so that the non-healthy leg is grounded in the order of the thumb ball and the toe. Accordingly, the thumb ball grounding sensor 55b is turned on first, and then the toe grounding sensor 55c is turned on. The above operations are repeated while walking. Therefore, the state of the unhealthy leg can be specified from the sensor data of the ground sensors 55a to 55c and the posture angle sensor 40.

  Next, the operation of the walking assist device 10 will be described. First, the operation of the walking assistance device 10 when the box 20, the knee brace 30, and the short leg brace 50 are worn and used will be described. As shown in FIGS. 1 and 2, the walking assistance device 10 is mounted, and the walking assistance device 10 starts operating by performing a predetermined operation with the operation switch of the box 20. When the operation is started, first, the controller determines whether or not a signal is input from the knee brace 30. When a signal is input from the knee brace 30, the controller executes a cooperative control program.

The flowchart of FIG. 4 shows processing defined by the cooperative control program.
In step S2 of FIG. 4, the controller determines whether any of the ground sensors 55a to 55c is on. That is, the controller determines whether the unhealthy leg is a ground leg or a free leg. If the unhealthy leg is a free leg (NO in step S2), the controller executes step S4. In step S4, the controller determines whether or not the upper leg is swinging (swinging) to the plus side based on the temporal change of the posture angle output from the posture angle sensor 40. When the upper leg is swung to the plus side (YES in step S4), the controller executes steps S6 and S8.

  In step S <b> 6, the controller controls the angle of the knee joint portion 36 of the knee brace 30 based on the posture angle output from the posture angle sensor 40. The appropriate angle of the knee joint during walking depends on the posture angle of the upper leg. The controller stores the target angle of the knee joint 36 when the upper thigh is swung forward according to the posture angle of the upper thigh. The controller outputs a target angle corresponding to the posture angle detected by the posture angle sensor 40 to the motor 38. Thereby, the knee joint part 36 is controlled to a target angle.

  In step S8, the controller controls the angle of the ankle joint 56 of the short leg brace 50. In step S <b> 8, the controller outputs the target angle set to 90 degrees to the motor 58. Thereby, the angle of the ankle joint part 56 is controlled to maintain 90 degrees.

  On the other hand, if the non-healthy leg is a grounded leg (in the case of YES in step S2), or if the non-healthy leg is a free leg but the upper leg is not swinging to the plus side (NO in step S4) Case), the controller executes steps S10 and S12.

  In step S <b> 10, the controller controls the angle of the knee joint portion 36 of the knee brace 30 based on the posture angle output from the posture angle sensor 40. The controller stores the target angle of the knee joint portion 36 according to the posture angle of the upper thigh when the non-healthy leg is a grounded leg and when the upper thigh is not swinging to the plus side. . This target angle is provided separately from the target angle used in step S6. The controller outputs a target angle corresponding to the posture angle detected by the posture angle sensor 40 to the motor 38. Thereby, the angle of the knee joint part 36 is controlled to a target angle.

In step S12, the controller torque-controls the ankle joint portion 56 of the short leg brace 50. That is, the controller inputs a torque target value to the motor 58. The motor 58 is driven so that a torque corresponding to the input target value is applied in a direction opposite to the direction in which the crus fixing part 52 swings with respect to the foot fixing part 54. At this time, the torque target value input to the motor 58 is changed according to the ground contact state of the non-healthy leg.
When all the ground sensors 55 a to 55 c are on, the controller inputs a first torque target value having a large absolute value to the motor 38. In other cases, the controller inputs a second torque target value whose absolute value is smaller than the first torque target value to the motor 38.

The controller repeatedly executes the process shown in FIG. Next, the process shown in FIG. 4 will be described more specifically.
If the non-healthy leg is a free leg and an operation of swinging the upper leg of the non-healthy leg to the plus side is executed, NO is determined in step S2 and YES is determined in step S4. Therefore, the controller executes steps S6 and S8. In step S6, the controller angle-controls the knee joint portion 36 to an angle corresponding to the posture angle of the upper leg. In step S8, the controller controls the angle of the ankle joint 56 to 90 degrees. While the operation of swinging the upper leg toward the plus side is being executed, the knee joint portion 36 and the ankle joint portion 56 are controlled by repeatedly executing steps S6 and S8. The knee joint part 36 is controlled to an angle corresponding to the posture angle of the upper leg as the upper leg swings. The angle of the ankle joint 56 is fixed at 90 degrees. This prevents the toes from hanging down when swinging the unhealthy leg forward. Therefore, the clearance between the foot tip and the walking surface is ensured, and the user is prevented from craving.

  When the operation of swinging the upper leg of the non-healthy leg to the plus side is completed, the non-healthy leg is moved so as to come into contact with the heel. During this operation (from the end of the operation of swinging the upper leg to the plus side until the heel contacts the ground), NO is determined in step S2 and NO is determined in step S4. Therefore, the controller repeatedly executes steps S10 and S12. In step S10, the controller controls the angle of the knee joint 36 to an angle corresponding to the posture angle of the upper leg. In step S12, the controller performs torque control on the ankle joint 56. In step S12, since all the ground sensors 55a to 55c are off, the controller controls the ankle joint portion 56 according to the second torque target value (small torque target value). Until the heel contacts the ground, the steps S10 and S12 are repeatedly executed to control the knee joint portion 36 and the ankle joint portion 56. The knee joint part 36 is controlled to an angle corresponding to the posture angle of the upper leg as the upper leg swings. The ankle joint portion 56 is controlled such that a constant torque (low torque) is applied in a direction opposite to the swinging direction. Since the angle of the ankle joint portion 56 is not fixed in the torque control, the user can move the ankle joint. Since the ankle joint can be moved immediately before the non-healthy leg is grounded, the user can ground the non-healthy leg without feeling uncomfortable. Further, since the ankle joint is supported by the torque control, an excessive load is not applied to the ankle joint at the time of grounding.

  When the heel of the unhealthy leg touches down, the heel ground sensor 55a is turned on. Therefore, it is determined YES in step S2. For this reason, the controller repeatedly executes steps S10 and S12 even after the bag is grounded. Since the ground sensors 55b and 55c are turned off when the heel is grounded, the ankle joint portion 56 is controlled in accordance with the second torque target value (small torque target value) in step S12. When the heel touches the ground, the foot swings in the direction of plantar flexion, and the toes and toes of the unhealthy legs are directed to the ground. The ankle joint portion 56 to which a low torque target value is given is driven so as to give a so-called viscous resistance against the swing in the plantar flexion direction. Due to this viscous resistance, the foot swings slowly in the plantar flexion direction, and the impact when the non-healthy leg toes and toes land is relieved.

  When the weight of the user moves to the non-healthy leg side after the heel of the non-healthy leg touches down, the thumb ball and the toe of the non-healthy leg touch down. That is, all of the ground sensors 55a to 55c are turned on. Also in this case, it is determined as YES in Step S2, and the controller repeatedly executes Steps S10 and S12. However, in this case, since all the ground sensors 55a to 55c are turned on, the controller controls the ankle joint portion 56 with the first torque target value (large torque target value) in step S12. Thus, in a state where most of the user's weight is applied to the non-healthy leg, the ankle joint 56 is controlled according to a large torque target value. While the entire sole is in contact with the ground, the entire unhealthy leg swings forward with the contact point as a fulcrum. A large torque target value provides resistance against forward swinging of the entire non-healthy leg. This further reduces the burden on the ankle joint of the non-healthy leg and prevents the non-healthy leg from wobbling.

  Thereafter, when the healthy leg is stepped on, the weight of the user moves to the healthy leg side. Then, the heel of the unhealthy leg leaves and the heel contact sensor 55a is turned off. Also in this case, since the ground sensors 55b and 55c are on, YES is determined in step S2. For this reason, the controller repeatedly executes steps S10 and S12. Further, since the ground sensor 55a is off, in step S12, the controller controls the ankle joint portion 56 according to the second torque target value (small torque target value). As described above, even after the heel is taken off, resistance is given to the swing of the ankle joint portion 56, and the ankle joint is assisted. Thereafter, when the unhealthy leg becomes a free leg again, the processes of steps S6 and S8 are executed again.

  As described above, when the box 20, the knee brace 30, and the short leg brace 50 are worn, the knee joint portion 36 is controlled based on the sensor data of the posture angle sensor 40, and the ankle joint portion 56 is Control is performed based on the sensor data of the attitude angle sensor 40 and the ground sensors 55a to 55c.

  Next, the operation of the walking assistance device 10 when only the box 20 and the short leg brace 50 are worn and used without wearing the knee brace 30 will be described. As shown in FIG. 3, the walking assistance device 10 is mounted, and the walking assistance device 10 starts operating by performing a predetermined operation with the operation switch of the box 20. In this case, since the signal from the knee brace 30 is not input to the controller, the controller executes the independent control program.

The flowchart of FIG. 5 shows processing defined by the independent control program.
In step S22 of FIG. 5, the controller determines whether any of the ground sensors 55a to 55c is on. That is, the controller determines whether the unhealthy leg is a ground leg or a free leg.

  If the non-healthy leg is a free leg (NO in step S22), the controller executes step S24. In step S24, the controller controls the angle of the ankle joint portion 56 of the short leg brace 50. In step S <b> 24, the target angle set to 90 degrees of the ankle joint portion 56 is input to the motor 58. Thereby, the ankle joint part 56 is controlled to 90 degrees. When the non-healthy leg is a free leg, the angle of the ankle joint portion 56 is fixed at 90 degrees, so that the foot tip is prevented from hanging down.

On the other hand, if the unhealthy leg is a grounded leg (YES in step S22), the controller executes step S26. In step S <b> 26, the controller torque-controls the ankle joint portion 56 of the short leg brace 50. That is, the controller inputs a torque target value to the motor 58. The motor 58 is driven so that a torque corresponding to the input target value is applied in a direction opposite to the swinging direction of the crus fixing part 52 with respect to the foot fixing part 54. At this time, the torque target value input to the motor 58 is changed in the same manner as in step S12 described above.
Therefore, when the non-healthy leg is a ground leg, the user can move the ankle joint to an intended angle, and resistance (torque) is applied in a direction opposite to the swinging direction. Thereby, the ankle joint is assisted so that the walking motion is smooth. When the majority of the user's weight is applied to the unhealthy legs (when all of the ground sensors 55a to 55c are on), the ankle joint is moved according to the first torque target value (large torque target value). Assisted. This further reduces the burden on the ankle joint and prevents the unhealthy leg from wobbling. Since the ankle joint is assisted by the second torque target value (small torque target value) when the unhealthy leg does not have so much weight (when any of the ground sensors 55a to 55c is off), Sudden rocking can be suppressed without preventing the user from adjusting the foot angle.

  As described above, when only the box 20 and the short leg brace 50 are worn without wearing the knee brace 30, the ankle joint portion 56 of the short leg brace 50 becomes the sensor data of the ground sensors 55a to 55c. Controlled based on. Even when the knee brace 30 is not worn, the user's walking can be assisted appropriately.

  As described above, in the walking assist device 10 of the embodiment, the knee brace 30 and the short leg brace 50 are configured separately (separated). Therefore, in the early stage of rehabilitation, walking training can be performed by wearing the knee brace 30 and the short leg brace 50. Further, if the walking motion becomes smooth due to rehabilitation, walking training can be performed by wearing the short leg brace 50 without wearing the knee brace 30. In addition, since the knee brace 30 and the short leg brace 50 are configured separately, the wearing position can be easily adjusted when these are worn.

  In the walking assist device 10, the controller detects whether or not the knee brace 30 is worn, and switches the control method of the ankle joint portion 56 of the short leg brace 50. The ankle joint 56 can be appropriately controlled according to whether or not the knee brace 30 is worn.

  In the above-described embodiment, the ground sensors 55a to 55c output on / off signals depending on whether they are grounded, but the ground sensors 55a to 55c may be pressure sensors that detect pressure. . In the case of a pressure sensor, it can be determined that the controller is grounded when the detected pressure is greater than or equal to a threshold value. Further, the threshold value may be changed between when the pressure increases and when the pressure decreases. For example, when the pressure is decreasing, it can be determined that the ground is below the first threshold, and when the pressure is subsequently increased, it can be determined that the ground is above the second threshold. If the threshold value is changed in this way, the ground / non-ground can be accurately determined.

  In the above-described embodiment, the battery and the controller are built in the box 20. However, the battery and the controller may be installed in the short leg brace 50. If the battery and the controller are installed on the short leg brace 50, the box 20 may be omitted. In the above-described embodiment, the controller communicates with each sensor and each servo motor by wire, but may be configured to communicate wirelessly.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

10: Walking assist device 20: Box 30: Knee orthosis 32: Upper thigh fixing part 34: Lower thigh fixing part 36: Knee joint part 38: Motor 40: Posture angle sensor 50: Short leg prosthesis 52: Lower thigh fixing part 54: Foot fixing Part 55a: Ground sensor 55b: Ground sensor 55c: Ground sensor 56: Ankle joint part 58: Motor

Claims (2)

A walking assist device that is worn on a non-healthy leg of a user whose one leg is a non-healthy leg,
A knee brace configured to be worn from a user's upper leg to lower leg and having an actuator that applies torque to the knee joint;
A short leg brace that is configured to be worn from the user's lower leg to the foot and has an actuator that applies torque to the ankle joint;
A controller for controlling the knee orthosis actuator and the short leg orthosis actuator;
A cord that can electrically connect the knee orthosis and the short leg orthosis,
With
The knee brace can be separated from the short leg brace by removing the cord ,
The knee brace has a posture angle sensor that detects the inclination angle of the upper leg,
The short leg brace has a grounding sensor that detects when the foot touches the floor,
The controller controls the knee brace and short leg brace actuators using the sensor data of the posture angle sensor and the ground sensor, and uses the sensor data of the ground sensor without using the sensor data of the posture angle sensor. A walking assist device configured to be able to switch an independent control mode for controlling an actuator of a short leg brace . The controller performs control to assist the user's walking movement,
In the coordinated control mode, when the condition that the ground sensor is off and the posture angle sensor detects that the upper thigh is swung forward is satisfied, the knee brace actuator and the short leg brace actuator are If the angle is controlled and the above condition is not satisfied, the knee brace actuator is angle controlled and the short leg brace actuator is torque controlled,
In the independent control mode, when the ground sensor is off, the angle of the actuator of the short leg brace is controlled by the angle, and when the ground sensor is on, the actuator of the short leg brace is torque controlled.
The walking assist device according to claim 1.

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