JP5732270B2 - Operation assist device and program for operation assist control - Google Patents

Description

  The present invention belongs to the technical field of motion assist devices and motion assist control programs. More specifically, it belongs to the technical field of, for example, a motion assist device used for recovery training of a patient with knee disease and a motion assist control program used in the motion assist device.

  In recovery training or the like (so-called rehabilitation) performed by a patient with knee disease, conventionally, the patient performed necessary recovery training or the like by himself / herself with the assistance of a physical therapist or the like. On the other hand, in recent years, other dynamic recovery training using a driving source such as a motor (such as recovery training using external force) has started. For such passive recovery training, a so-called wearable walking assist robot that is worn on the patient's body and assists the movement of the knee joint during walking is used. This walking assist robot is attached to the upper thigh and lower thigh including a patient's knee joint using a harness or the like, and operates to assist the movement of the knee joint (in other words, forcibly move). . That is, the walking assist robot operates to move the knee joint so that the movement as the knee joint in an appropriate walking pattern is realized. Thus, the patient can perform necessary recovery training and the like by walking independently so as to follow the movement by the walking assist robot.

  On the other hand, if the patient cannot follow the movement of the walking assist robot during recovery training, or if the patient fluctuates due to various causes, the patient will be in an unstable gait state, and in the worst case, the patient may fall and cause unexpected injury. there's a possibility that. In addition, conventional walking assist robots include, for example, a rechargeable battery, a CPU, various sensors, actuators, and the like, and are often large devices that should be worn including the entire lower limbs. The risk is further increased. Therefore, usually, the physical therapist or the like accompanies patient recovery training and the like to prevent falls. Alternatively, in order to reduce the damage to the patient who falls with the walking assist robot, the floor of the training room and the clothes worn by the patient are made of a soft material with cushioning properties.

  As an apparatus for assisting human walking that can be used for the recovery training or the like, for example, there is a walking assist apparatus described in Patent Document 1 below.

JP 2003-135543 A

  However, in the above-described recovery training or the like, an appropriate hardness is required for the floor of the training room. In addition, the burden on the physical therapist and the like who accompanies is increasing, and it is becoming difficult to see the troubles of a plurality of patients at the same time. Furthermore, there is a recognition that the conventional walking assist robot lacks safety regarding the fall of the patient, which may hinder the spread of the robot.

  With respect to this point, the walking assist device described in Patent Document 1 does not take into consideration the above-described viewpoint of preventing the patient from falling. Therefore, the walking assist device described in Patent Document 1 cannot solve the above problems.

  Therefore, the present invention has been made in view of the above-mentioned problems and the like, and an example of the problem is an operation assisting device capable of autonomously and safely assisting in patient recovery training as described above. And providing an operation assistance control program used in the operation assistance device.

In order to solve the above-mentioned problem, the invention according to claim 1 is an operation assisting device for assisting an assisting person's movement while walking on a walking surface, and is attached to a knee joint portion of the assisting person's leg. Auxiliary means such as a drive unit for assisting bending motion of the knee joint part accompanying walking and extension operation of the knee joint part accompanying walking, and a leg on which the auxiliary means is mounted A heel state detecting means such as a sole sensor for detecting that the heel of the limb has moved away from the walking surface, a knee joint angle detecting means such as a knee joint angle sensor for detecting a bending angle of the knee joint portion, a hip joint angle detection unit of the hip joint angle sensor for detecting the bending angle of the hip, with the heel to control the pre-Symbol auxiliary means to start assisting the bending motion from the timing away from the plane of walking, the Knee joint flexion angle And a control unit such as a CPU for controlling the auxiliary means so as to initiate the assistance of the stretching operation from a timing that the bending angle reaches a preset threshold angle to the hip according to the maximum value.

According to the first aspect of the present invention, it is detected that the heel has moved away from the walking surface, and the assisting means is controlled so as to start assisting the bending motion of the knee joint from the timing at which the heel has moved away from the walking surface. Therefore, by starting the assistance of the bending operation from the timing when the heel is separated from the walking surface by the supportee's intention, the operation can be assisted autonomously and safely along the supportee's intention.
In addition, it detects the bending angles of the knee joint and hip joint, and starts assisting the extension operation when the hip joint bending angle reaches the threshold angle set according to the maximum knee joint bending angle. Therefore, the operation can be safely assisted without imposing a burden on the person being assisted by control close to a natural walking mode.

In order to solve the above-mentioned problem, the invention according to claim 2 further includes changing means such as an operation unit used for changing the threshold angle in the motion assisting device according to claim 1 .

According to the second aspect of the invention, in addition to the action of the first aspect of the invention, the threshold value used for the start control of the extension operation can be changed, so that the operation according to the condition of the person being assisted Can assist.

In order to solve the above-described problem, the invention according to claim 3 is the operation assisting device according to claim 1 or 2 , wherein the auxiliary means is driven by a drive signal modulated by a pulse width modulation method. And the control means is configured to control the auxiliary means by the drive signal whose duty ratio changes in a trapezoidal shape along a time axis.

According to the invention described in claim 3 , in addition to the operation of the invention described in claim 1 or 2 , the auxiliary means is a drive signal modulated by the pulse width modulation method, and the duty ratio thereof is time. Since it is controlled by a drive signal that changes in a trapezoidal shape along the axis, it is possible to suppress a sudden movement and safely assist the movement without burden on the person being assisted.

In order to solve the above-described problem, the invention according to claim 4 is the motion assisting device according to any one of claims 1 to 3 , wherein the heel is separated from the walking surface in advance. When not detected within a set time, the control means is configured to initialize the auxiliary means.

According to the invention described in claim 4 , in addition to the action of the invention described in any one of claims 1 to 3 , assistance is provided when it is not detected that the heel has separated from the walking surface within a certain time. Since the means is initialized, when it is considered that the assisting person does not intend to walk without raising the heel, the assisting means is initialized so that the assisting means can bend regardless of the willingness of the assisting person. The danger of starting assistance can be avoided.

In order to solve the above-described problem, the invention according to claim 5 is the movement assist device according to any one of claims 1 to 4 , wherein the control means is a right leg of the person being assisted. The auxiliary means mounted on the left side and the auxiliary means mounted on the left leg of the person being assisted are configured to be controlled separately and independently.

According to the invention described in claim 5 , in addition to the operation of the invention described in any one of claims 1 to 4 , the auxiliary means is controlled separately for the right leg and the left leg. Therefore, the process as a control means can be simplified.

In order to solve the above-mentioned problem, the invention described in claim 6 is characterized in that a computer provided as the control means in the operation assisting device according to any one of claims 1 to 5 is provided as the control means. To function as.

According to the sixth aspect of the present invention, it is detected that the heel has moved away from the walking surface, and the assisting means is controlled so as to start assisting the bending motion of the knee joint from the timing when the heel has moved away from the walking surface. Since the computer functions, assisting the operation autonomously and safely in accordance with the intention of the assistant by starting the assistance of the bending movement from the timing when the heel is separated from the walking surface by the intention of the assistant Can do.
In addition, it detects the bending angles of the knee joint and hip joint, and starts assisting the extension operation when the hip joint bending angle reaches the threshold angle set according to the maximum knee joint bending angle. Since the computer that controls the auxiliary means functions as described above, the operation can be safely assisted without imposing a burden on the person being assisted by control close to a natural walking mode.

According to the present invention, it is detected that the heel has moved away from the walking surface, and the assisting means is controlled to start assisting the bending motion of the knee joint from the timing when the heel has moved away from the walking surface.
Therefore, by starting the auxiliary bending operation from a timing that the heel by intention of the assistant has left the tread surface, it is possible to assist the autonomously and safely operation of that along the intention of the assistant.
In addition, it detects the bending angles of the knee joint and hip joint, and starts assisting the extension operation when the hip joint bending angle reaches the threshold angle set according to the maximum knee joint bending angle. To do.
Therefore, the control close to the natural walking mode can assist the operation safely without placing a burden on the person being assisted.

It is a state figure at the time of mounting the walk auxiliary device concerning an embodiment on a patient. It is a state figure at the time of mounting | wearing the patient's both legs with the drive unit which concerns on embodiment. It is a block diagram which shows the structure of the walking assistance apparatus which concerns on embodiment. It is a flowchart which shows the operation example which produces | generates the control pattern in the walking assistance apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the bending angle of the knee joint part and hip joint part in the walking assistance apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the data and control pattern of the sensor in the walking assistance apparatus which concerns on embodiment. It is a flowchart which shows the example of control operation in the walking assistance apparatus which concerns on embodiment. It is a schematic diagram which shows an example of the other control pattern in the walking assistance apparatus which concerns on embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  A mode for carrying out the present invention will be described with reference to FIGS. In the embodiment described below, for example, when the present invention is applied to a walking assist device that assists the operation of a knee joint in walking as a recovery training for a patient with knee disease (an example of an assistant) It is an embodiment. FIG. 1 is a state diagram when the walking assist device according to the embodiment is mounted on a patient, and FIG. 2 is a state diagram when the drive unit according to the embodiment is mounted on both legs of the patient. FIG. 3 is a block diagram showing the configuration of the walking assistance device. FIG. 4 is a flowchart showing an operation example of generating a control pattern in the walking assistance device. Furthermore, FIG. 5 is a schematic diagram showing an example of bending angles of the knee joint part and the hip joint part in the walking assist device. FIG. 6 is a schematic diagram illustrating an example of sensor data and a control pattern in the walking assist device. FIG. 7 is a flowchart illustrating an example of a control operation in the walking assist device. FIG. 8 is a schematic diagram showing an example of another control pattern in the walking assistance device.

  As shown in FIGS. 1 and 2, the walking assist device S (an example of a motion assist device) according to the embodiment includes a tape-like fixture and a fixture 6 such as a band that can be attached to and detached from the lower limbs (both legs) of a patient. A pair of drive units 10 is provided as an example of auxiliary means attached to each. In the following description, the drive unit 10 for the left leg is referred to as the drive unit 11, and the drive unit 10 for the right leg is described as the drive unit 12. In addition, when a description common to the drive unit 11 and the drive unit 12 is performed, the drive unit 10 is generally described.

  As shown in FIG. 1, one drive unit 10 (ie, for either the right leg or the left leg) is attached to a joint portion of a patient's knee 5 and is a link that flexes and extends the knee joint. The mechanism part 3 and the link mechanism part 8 which is attached to the joint part of the patient's crotch part 9 to bend and extend the hip joint are attached.

  First, as shown in FIG. 1, the link mechanism unit 3 includes, for example, a first link 3a attached to the side surface of the upper leg rest 4 wound around the patient's thigh and a lower leg wound around the patient's lower leg. A second link 3b attached to the side surface of the abutment 7, and a third link 3c that obtains power from the drive unit 10 and swings the second link 3b in the front-rear direction of walking with respect to the first link 3a. Composed. The first link 3a is attached so as to extend from the patient's waist side to the knee portion 5 side, and the second link 3b is attached so as to extend from the patient's knee portion 5 side to the tip (ground) side of the leg. And the 1st link 3a and the 2nd link 3b are connected so that rotation in the patient's knee part 5 vicinity is possible.

  The connecting portion incorporates a knee joint angle sensor (an example of a knee joint angle detection means) that outputs knee joint angle data indicating an angle formed by the first link 3a and the second link 3b. This knee joint angle sensor is realized by, for example, a so-called potentiometer. Moreover, the edge part of the 3rd link 3c is connected with the center vicinity of the 2nd link 3b. Each of the upper leg rest 4 and the lower leg rest 7 includes a pair of leg rest members (not shown), and the leg rest members are arranged so as to cover the circumference of the patient's thigh and lower leg. The fixing device 6 is detachably attached. The upper leg rest 4 and the lower leg rest 7 are formed by molding, for example, polypropylene resin, and a stretchable sponge member (not shown) or the like is attached to a portion in contact with the user's thigh. .

  On the other hand, as shown in FIG. 1, the link mechanism portion 8 includes a first link 8 a attached to the side surface of the upper leg rest 4 and a second link 8 b attached to the side portion of the belt 23 wound around the patient's waist. And comprising. The first link 8a is attached to extend from the patient's buttocks side to the knee 5 side, and the second link 8b is attached to extend from the patient's waist side to the buttocks side. And the 1st link 8a and the 2nd link 8b are connected so that rotation in the patient's crotch part 9 vicinity is possible. The connecting portion also incorporates a hip joint angle sensor (an example of a hip joint angle detection unit) that outputs hip joint angle data indicating an angle formed by the first link 8a and the second link 8b. This hip joint angle sensor is also realized by a so-called potentiometer, for example.

  Further, as shown in FIG. 2, a communication unit 20 for data communication between the drive unit 11 and the drive unit 12 is detachably attached to the drive unit 11 and the drive unit 12 which are respectively attached to both legs. The communication unit 20 includes a cable 21 and a relay box 22 containing a communication board, a control board, a battery, and the like disposed in the middle of the cable 21, and is attached to the patient's waist by the belt 23. It is done. In addition, the communication unit 20 includes a communication head 25 including communication terminals that can communicate data without contact at both ends of the cable 21. On the other hand, the housing 10a of the drive unit 10 is provided with a hole 10b into which the communication head 25 can be inserted, and the communication head 25 can be attached to and detached from the hole 10b. The control board in the relay box 22 is equipped with a CPU, which will be described later, for controlling the operation as the walking assist device S according to the embodiment. Furthermore, the drive unit 10 includes a communication head (not shown) capable of receiving power or communicating predetermined data inside the housing 10a. And the communication head 25 is inserted in the hole 10b which the housing | casing 10a of the drive unit 10 has, and is electrically connected to the communication head which is not shown in figure without contact, and data communication is possible.

  Next, the configuration of the walking assist device S of the embodiment will be described more specifically with reference to FIG.

  As shown in FIG. 3, the walking assistance device S of the embodiment includes a CPU (Central Control Unit) as an example of a control unit provided on the control board in the right foot drive system R, the left foot drive system L, and the relay box 22. Processing Unit) 42, an operation unit 41 as an example of changing means provided at a position where a patient or a physical therapist can operate and an operation button for performing a command operation on the CPU 42, and the CPU 42 And a display unit 40 including a liquid crystal display or the like provided at a position where a patient, a physical therapist, or the like can visually recognize. The CPU 42 stores software such as a control program for controlling the operating system and the walking assist device S, a control pattern generation program for generating a control pattern, data such as detected data and a generated control pattern. A storage unit (not shown) is included. The storage unit is configured by a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk, a silicon disk, or the like.

  The drive system for each leg (right foot drive system R and left foot drive system L) includes the drive unit 10, the fixture 6, the upper leg rest 4, the lower leg rest 7, and the knee joint angle sensor 16, respectively. A link mechanism unit 3 including the link mechanism unit 8 including the hip joint angle sensor 15 and a sole sensor 17 as an example of a heel state detecting unit are included. The drive unit 10 includes a DC motor 50 as an example of a drive unit, a gear unit 52 connected to each link, and a drive that transmits a driving force from the DC motor 50 to each link via the gear unit 52. And a clutch portion 51 as an example of means.

  In the above configuration, the control of the rotation direction and rotation speed of the DC motor 50 and the control of the release / connection in the clutch unit 51 are performed by the CPU 42, respectively. Further, as shown in FIG. 1, the sole sensor 17 is attached to the soles of the right foot and the left foot, respectively, and signals to the CPU 42 indicating that each leg has left the floor or the ground and grounded them. Output. The knee joint angle sensor 16 generates the knee joint angle data and outputs it to the CPU 42, and the hip joint angle sensor 15 generates the hip joint angle data and outputs it to the CPU 42.

  Next, control pattern generation in the walking assistance device S having the configuration described with reference to FIGS. 1 to 3 will be specifically described with reference to FIGS. 4 to 6.

  First, the walking assist device S is attached to the patient, and a control pattern generation process is performed.

  As shown in FIG. 4, the walking assistance device S opens the clutch unit 51 (step S1). Specifically, the CPU 42 of the walking assist device S opens the clutch unit 51 and interrupts transmission of the driving force from the DC motor 50 to the link mechanism unit 3. Thereby, the link mechanism part 3 moves freely without being influenced by the resistance force by the permanent magnet of the DC motor 50 and the patient can easily move the leg.

  Next, the walking assist device S acquires the data of the hip joint angle sensor 15 and determines the correction value of the hip joint angle (step S2). When the patient wearing the walking assist device S is in a stationary state, the CPU 42 determines from the hip joint angle sensor 15 the angle θH formed by the first link 8a and the second link 8b (an example of the bending angle of the hip joint). Angle data is acquired and used as a correction value for the angle θH. The CPU 42 stores the acquired hip joint angle data in the storage unit of the CPU 42. When the patient is moving and the data is fluctuated, the CPU 42 calculates the average value of the hip joint angle data and sets this average value as the correction value of the angle θH.

  Here, as shown in FIG. 5A, the angle θk at the joint of the patient's knee 5 is measured with reference to the thigh of the patient 60 (corresponding to the first link 3a). The angle θH at the joint portion of the patient's crotch 9 is measured with reference to the trunk of the patient 60 (corresponding to the second link 8b), and the case where the thigh of the patient 60 is behind the walking direction from the reference is a plus. The case where it is ahead in the walking direction is negative. The walking surface 65 is a floor or the ground.

  FIG. 5A shows the case where the patient 60 walks upright without any shift in the wearing position of the walking assist device S. On the other hand, as shown in FIG. 5B, since there is a case where the patient 60 has a wrinkle such as walking forward or there is a case where there is a shift in the wearing position of the walking assist device S, the CPU 42 corrects the angle θH. As (angle α), hip angle data is acquired in step S2 as corrected angle φ = θH−α.

  Next, when the patient 60 wearing the walking assist device S walks about three or four steps, the walking assist device S acquires data of the hip joint angle sensor 15, the knee joint angle sensor 16, and the sole sensor 17. (Step S3). Specifically, the CPU 42 acquires hip joint angle data indicating the angle θH from the hip joint angle sensor 15, and from the knee joint angle sensor 16, the angle θk formed by the first link 3a and the second link 3b (of the knee joint portion). Knee joint angle data indicating an example of a bending angle is acquired. With respect to the sole sensor 17, the CPU 42 acquires a signal indicating from the sole sensor 17 that the leg has moved away from the walking surface 65 such as the floor or the ground and touched them.

  As shown in FIG. 6, the CPU 42 acquires knee joint angle data indicating the angle θk from the knee joint angle sensor 16, acquires hip joint angle data indicating the angle θH from the hip joint angle sensor 15, and receives from the sole sensor 17. The data Sh of the sole sensor is acquired. The CPU 42 stores the acquired hip joint angle data, knee joint angle data, and data of the sole sensor 17 in the storage unit of the CPU 42.

  Next, the walking assistance device S determines the threshold value of the foot sensor data Sh based on the acquired foot sensor data Sh (step S4). Specifically, as shown in FIG. 6, the CPU 42 sets a threshold value (foot sole sensor ON threshold) that the foot sensor data Sh changes from LOW to HIGH, or a foot sensor data Sh changes from HIGH to LOW. The threshold value (foot sensor OFF threshold value) to be set is set from the acquired foot sensor data Sh. In order to prevent chattering, the sole sensor ON threshold and the sole sensor OFF threshold may be different.

  Next, the walking assistance device S specifies the walking cycle, the swing phase, and the stance phase based on the data of the sole sensor 17 (step S5). Specifically, as shown in FIG. 6, the CPU 42 detects that the foot sensor data Sh is LOW (from the time ta when the foot sensor data Sh becomes HIGH (a state where the legs are separated from the floor or the ground). After the time td when the leg is in contact with the floor or the ground), the period T3 from the time when the foot sensor data Sh becomes HIGH again to the time te (from the time when the heel leaves (ta) to the next heel The time of getting out (te) is specified as the walking cycle. Then, as shown in FIG. 6, the CPU 42 changes the time td when the foot sensor data Sh becomes LOW from the time ta when the foot sensor data Sh becomes HIGH from the time td when the foot sensor data Sh becomes LOW. The time from the time when the foot sensor data Sh becomes HIGH from the time td when the foot sensor data Sh becomes LOW from the time when the foot sensor data Sh becomes LOW. The period up to te is specified as the stance phase (T3-T2).

  In FIG. 6, the “stance phase” indicates a period during which the patient's weight is applied to either the left or right leg during walking. In addition, the “swing leg” is a period in which the patient's weight is not applied to one of the legs during walking (in other words, the leg is separated from the floor or the ground in order to enter the next stance phase ( Floating) Indicates the period of movement).

  Next, the walking assist device S identifies the peak portion of the knee joint angle data (step S6). Specifically, the CPU 42 determines that the acquired knee joint angle data indicating the angle θk from the knee joint angle sensor 16 has the maximum peak position θkp, that is, the knee joint bend angle at the maximum during the swing phase. An extreme value timing tb is specified. As shown in FIG. 5A, the maximum value of the knee joint bending angle is a value based on the thigh of the patient 60, and the knee is in the most bent state.

  Next, the walking assist device S sets a threshold angle related to the hip joint (step S7). Specifically, the CPU 42 obtains an angle θH1 that is hip joint angle data at the extremum timing tb and sets it as a threshold angle θH1 related to the hip joint. As shown in FIG. 6, the threshold angle θH1 is used to set a bending motion assisting period T1 (extremum timing tb of the knee joint peak θkp from the heel leaving bed ta).

  Next, the walking assist device S sets a bending motion trigger and an extension motion trigger (step S8). Specifically, in the control pattern, the CPU 42 sets an auxiliary start trigger (bending motion trigger) for starting auxiliary control (especially auxiliary control of bending motion) in the swing phase, and the data of the foot sensor 17 indicates the foot sensor. It is set when the threshold value is equal to or higher than the ON threshold (tape bed leaving ta). In addition, the CPU 42 sets an auxiliary end trigger for ending auxiliary control (especially auxiliary control for extension operation) during the swing phase in the control pattern when the data of the foot sensor 17 is equal to or lower than the foot sensor OFF threshold value (wearing the heel). Set to floor time td). In the control pattern, the CPU 42 sets an extension operation trigger for switching from the auxiliary control of the flexion operation in the swing phase to the auxiliary control of the extension operation, and the hip joint angle data indicating the angle θH from the hip joint angle sensor 15 is a threshold value. It is set when the angle θH1 or less (extreme timing tb).

  Next, the walking assistance device S generates a drive signal pattern for knee joint control (step S9). Specifically, the CPU 42 generates a drive signal D in which the duty ratio of PWM (Pulse Width Modulation) changes to a trapezoidal shape along the time axis as shown in FIG. As shown in FIG. 6, in the walking assist device S, the control of the assisting operation is assigned to the time from t1 to t7, and the time ta when the leg heel is separated from the floor or the ground is the starting point of walking (starting point of assistance). The rising time of the drive signal C in the bending operation is time t1, the duration when the PWM duty ratio is 100% is t2, the falling time is t3, and a positive trapezoidal waveform. At time t1, in order to speed up the start-up, the CPU 42 starts from, for example, about 35% instead of the duty ratio from 0%. Further, the falling time of the extending operation is t4, the duration of the PWM duty ratio is −100% is t5, the rising time is t6, and a negative trapezoidal waveform is obtained. In addition, the CPU 42 stores the generated control pattern in the storage unit of the CPU 42.

  For the drive signal C, the rise and fall times are, for example, t1, t3, t4, t6 = 0.1 seconds. Then, the duration t2 is calculated as t2 = T1-t1-t3 from the bending motion assisting period T1. The duration t5 is calculated as follows: t5 = T2−T1−t4−t6 from the bending motion assisting period T1 and the swing leg period T2.

  The time t7 in the stance phase is the extension extension time for the origin of the machine in the walking assist device S even after the leg bending and extension operations are completed. The time t7 is calculated as t7 = a × (T3−T2) from the walking cycle period T3 and the swing leg period T2. Here, the coefficient a is a value from 0 to 1. In the case of a = 1, the force of the extension operation is applied to the leg little by little during the stance phase.

  Next, the operation | movement at the time of control in the walking assistance apparatus S is demonstrated using FIG.

  In the operation at the time of control in the walking assist device S, the CPU 42 reads the control pattern of the drive signal D from the storage unit (step S10), and assists the operation of the patient 60 wearing the walking assist device S according to the control pattern. That is, when the operation assistance is started, the CPU 42 monitors, for example, whether or not the data of the sole sensor 17 of one leg (for example, the right leg) of the patient is equal to or more than the sole sensor ON threshold value. (Step S11). When the data of the foot sensor 17 is not equal to or more than the foot sensor ON threshold in the monitoring in step S11 (step S11; NO), the CPU 42 continues to monitor as it is, and the right foot drive system R is raised by the patient raising the right leg. When the data of the sole sensor 17 becomes equal to or more than the sole sensor ON threshold (when the auxiliary start trigger is detected, step S11; YES), the CPU 42 determines the duty of the PWM according to the control pattern of the drive signal D. The ratio is gradually increased to start driving the DC motor 50 of the right foot drive system R (step S12). Then, the driving force is transmitted to the link mechanism unit 3 via the gear unit 52 and the clutch unit 51, and the knee of the patient's right leg begins to bend. In parallel with this, the CPU 42 starts monitoring the hip joint angle data indicating the angle θH from the hip joint angle sensor 15 (step S12).

  Next, the CPU 42 determines whether or not the time t1 (see FIG. 6) has elapsed since the start of driving (step S13). When the time t1 has not elapsed (step S13; NO), the bending operation is continued. On the other hand, when the time t1 has elapsed (step S13; YES), the CPU 42 sets the duty ratio of PWM to 100% (step S14).

  Next, the CPU 42 determines whether or not the time (t1 + t2) (see FIG. 6) has elapsed since the start of driving (step S15). When the time (t1 + t2) has not elapsed (step S15; NO), the PWM When the time (t1 + t2) has elapsed (step S15; YES), the CPU 42 starts to gradually decrease the PWM duty ratio (step S16). Then, the driving force applied to the knee of the patient's right leg begins to decrease.

  Next, the CPU 42 determines whether time (t1 + t2 + t3) (see FIG. 6) has elapsed from the start of driving, or whether the hip joint angle data indicating the angle θH from the hip joint angle sensor 15 is equal to or greater than the threshold angle θH1 (see FIG. 6). Step S17). If it is determined in step S17 that the time (t1 + t2 + t3) has not elapsed since the start of driving and the hip joint angle data indicating the angle θH is not equal to or greater than the threshold angle θH1 (step S17; NO), the CPU 42 performs the bending operation as it is. When the time (t1 + t2 + t3) has elapsed from the start of driving, or when the hip joint angle data indicating the angle θH is equal to or greater than the threshold angle θH1 (when an extension operation trigger is detected; step S17; YES), the CPU 42 Then, the control is switched from the auxiliary control of the bending operation in the swing leg period to the auxiliary control of the extension operation (step S18). The PWM duty ratio is inverted from positive to negative. Here, as shown in FIG. 6, the knee joint angle data indicating the angle θk from the knee joint angle sensor 16 is the extreme value timing tb, and the hip joint angle data indicating the angle θH from the hip joint angle sensor 15 is the extreme value. Since it is before tc (timing at which the hip joint portion starts to appear forward), the walking assist device S assists the extension operation earlier than the timing tc.

  Next, the CPU 42 determines whether or not the time t4 (see FIG. 6) has elapsed since the start of the extension operation (step S19). If the time t4 has not elapsed since the start of the extension operation (step S19; NO), the CPU 42 continues. When the extension operation is continued and time t4 has elapsed from the start of the extension operation (step S19; YES), the CPU 42 continues the extension operation with the PWM duty ratio set to −100% (step S20).

  Next, the CPU 42 determines whether or not the time (t4 + t5) (see FIG. 6) has elapsed since the start of the extension operation (step S21). When the time (t4 + t5) has not elapsed (step S21; NO), The extension operation is continued with the PWM duty ratio set to −100%, and when the time (t4 + t5) has elapsed (step S21; YES), the CPU 42 starts to gradually increase the PWM duty ratio (step S22).

  Next, the CPU 42 has elapsed time (t4 + t5 + t6) (refer to FIG. 6; period T2 of the swing leg period) from the start of the extension operation, or the data of the sole sensor 17 of the right foot drive system R is below the sole sensor OFF threshold. It is determined whether or not (step S23). If it is determined in step S23 that the time (t4 + t5 + t6) has not elapsed since the start of the extension operation and the data of the sole sensor 17 is not less than or equal to the sole sensor OFF threshold (step S23; NO), the CPU 42 remains as it is. When the extension operation is continued and time (t4 + t5 + t6) has elapsed from the start of the extension operation, or when the data of the sole sensor 17 of the right foot drive system R becomes less than the sole sensor OFF threshold (the auxiliary end trigger is detected) (Step S23; YES), the CPU 42 next extends the extension operation by about −30% without setting the PWM duty ratio to 0% in order to find the origin of the machine in the walking assist device S (step S23; YES). Step S24). Then, the CPU 42 determines whether or not time t7 (see FIG. 6) has elapsed since the end of the swing leg period (step S25). When the time t7 has not elapsed in the determination in step S25 (step S25; NO), the CPU 42 continues to extend the extension operation as it is. On the other hand, when the time t7 has elapsed (step S25; YES), the CPU 42 ends the assistance for the right leg.

  When the left foot drive system L is attached, the walking assistance device S performs the same control for the left foot drive system L.

  As described above, according to the operation of the walking assist device S according to the embodiment, it is detected that the patient's heel has been separated from the walking surface, and the knee joint is bent from the timing at which the heel is separated from the walking surface. Since the DC motor 50 is controlled so as to start the assist of the patient, the support of the bending motion is started from the timing when the heel is separated from the walking surface by the intention of the patient 60, so that the patient 60 is independent and safe in accordance with the intention of the patient 60. The operation can be assisted.

  Further, the bending angle of each of the knee joint part and the hip joint part is detected, and the extension operation is assisted from the timing when the bending angle of the hip joint part reaches the threshold angle θH1 set according to the maximum value of the knee joint bending angle. Since it starts, the operation can be assisted safely without imposing a burden on the person being assisted by control close to a natural walking mode.

  Further, since the DC motor 50 is controlled by the drive signal D that is modulated by PWM and whose duty ratio changes in a trapezoidal shape along the time axis, the sudden operation is suppressed and the assistance is performed. The operation can be safely assisted without any burden on the user.

  Furthermore, since the control of the DC motor 50 is performed independently for the right leg and the left leg, the processing as the CPU 42 can be simplified.

  Next, an example of another control pattern in the walking assistance device S will be described with reference to FIG. FIG. 8 is a schematic diagram illustrating an example of another control pattern in the walking assist device S according to the embodiment.

  The threshold angle θH1 according to the embodiment can be changed by, for example, the operation of the operation unit 41, for example, by the intention of the patient 60 or the physical therapist. In this case, for example, as shown in FIG. 8, when the set threshold angle is changed from θH1 to θH2, the auxiliary control of the bending motion during the swing phase is switched to the auxiliary control of the extension motion in the control pattern of the drive signal D2. Timing tf is earlier than time (tb). In other words, the extension operation is started early on the patient's leg and acts as a load, so that the rehabilitation effect can be enhanced and the operation according to the condition of the patient 60 can be performed. The value of the threshold angle θH2 is determined according to the patient's condition, rehabilitation schedule, and the like. Here, the duration t8 when the PWM duty ratio is 100% is shorter than the duration t2 in the control pattern of the drive signal D, and the duration when the PWM duty ratio is −100% is t9, It becomes longer than the duration t5 in the control pattern.

Further, the walking assist device S generates a control pattern for initializing the assisting means (drive units 10, 11, 12) when it is not detected within a preset time that the heel has moved away from the walking surface 65. Also good. For example, if in a state where the patient is standing not walk this, consider that there is no intention of walking to the patient, the walking assist device S to reset the state of the drive unit 10, 11 and 12, control of a series of walking Stop pattern generation. In this case, when it is not detected that the heel has moved away from the walking surface 65 within a certain period of time, the auxiliary means (drive units 10, 11, 12) are initialized, so that the leg can be lifted without the patient's intention to walk. Since the assisting operation is not performed even if it is raised, it is possible to prevent assisting in a manner contrary to the patient's intention, and the clutch part 51 is opened so that the patient can freely move the leg. It is possible to improve convenience in assisting the operation of the person being assisted. Furthermore, it is possible to avoid the danger that the DC motor 50 starts assisting the bending operation regardless of the will of the patient 60.

  In the above-described embodiment, the case where the present invention is applied to the walking assist device S that assists walking as recovery training or the like of a patient having knee disease has been described. The present invention can also be applied to a movement assisting device that assists movement such as running as a part.

  Further, a program corresponding to the flowchart shown in FIG. 4 or 7 is recorded on a recording medium such as a flexible disk, a compact disk, or a hard disk, or obtained and stored via a network such as the Internet, By reading and executing with a general-purpose microcomputer, the microcomputer can be operated as the CPU 42 according to the embodiment.

  As described above, the present invention can be used in the field of motion assist devices, and is particularly noticeable when applied to the field of motion assist devices that assist recovery training such as walking or running of a patient. An effect is obtained.

3, 8 Link mechanism part 3a, 8a First link 3b, 8b Second link 3c Third link 4 Upper leg rest 5 Knee part 6 Fixing tool 7 Lower leg rest 9 Crotch part 10, 11, 12 Drive unit 10a Case 10b Hole part 15 Hip joint angle sensor 16 Knee joint angle sensor 17 Foot sensor 20 Communication unit 21 Cable 22 Relay box 23 Belt 25 Communication head 40 Display part 41 Operation part 42 CPU
50 DC motor 51 Clutch part 52 Gear part S Walking assist device R Right foot drive system L Left foot drive system

Claims (6)

In the movement assist device that assists the movement of the assistance person while walking on the walking surface,
Auxiliary means attached to the knee joint portion of the leg of the person being assisted, and assisting the bending operation of the knee joint portion accompanying the walking and the extending operation of the knee joint portion accompanying the walking,
Heel state detection means for detecting that the heel of the leg on which the auxiliary means is mounted is separated from the walking surface;
Knee joint angle detection means for detecting the bending angle of the knee joint,
Hip joint angle detecting means for detecting a bending angle of the hip joint portion of the leg;
The auxiliary means is controlled so as to start assisting the bending motion from the timing when the heel is separated from the walking surface, and the threshold angle is set in advance according to the maximum value of the knee joint bending angle. Control means for controlling the auxiliary means so as to start the assistance of the extension operation from the timing when the bending angle of the hip joint portion has reached;
A motion assisting device comprising: The motion auxiliary device according to claim 1,
The operation assisting device further comprising changing means used for changing the threshold angle. In the movement auxiliary device according to claim 1 or 2,
The auxiliary means is auxiliary means driven by a drive signal modulated by a pulse width modulation method,
The operation assisting device, wherein the control means controls the assisting means by the drive signal whose duty ratio changes in a trapezoidal shape along a time axis. In the movement auxiliary device according to any one of claims 1 to 3,
The operation assisting device, wherein the control means initializes the assisting means when it is not detected within a preset time that the heel has left the walking surface. In the movement auxiliary device according to any one of claims 1 to 4,
The control means separately controls the auxiliary means attached to the right leg of the assistant and the auxiliary means attached to the left leg of the assistant. Operation assistance device. 6. An operation assistance control program that causes a computer provided as the control means in the operation assistance apparatus according to any one of claims 1 to 5 to function as the control means .

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