JP7212889B2 - Assist device and assist clothing and assist control program - Google Patents

Description

The present disclosure relates to an assist device, assist clothing, and an assist control program that provide relatively light assistance in standing and walking motions.

In Japan, which has become a super-aged society, the number of patients with "locomotive syndrome", in which the ability to stand up, sit down, and walk has decreased due to dysfunction of the locomotorium, is increasing. Locomotive syndrome is a concept proposed by the Japanese Orthopedic Association in 2007. It is said that about half of all cases are caused by joint diseases, debilitation due to old age, fractures and falls.

In this way, locomotive syndrome includes diseases related to the locomotive organs themselves and locomotive dysfunction due to aging. It is becoming one of the serious social issues leading to

Therefore, conventionally, wearable robots have been developed that assist daily life activities such as standing up and walking. Many of them use a rigid exoskeleton frame or a large actuator for high output in order to fully support the weight (Patent Document 1).

On the other hand, in recent years, attention has been focused on the development of wearable robots using soft actuators (Patent Document 2, Non-Patent Document 1). Soft actuators are inferior to exoskeleton-type assist robots that use electromagnetic motors in terms of power, but the overall system is lightweight and has the advantage of compatibility with the wearer. Therefore, it is suitable for elderly people and disabled people who can be independent to some extent.

Non-Patent Literature 1 discloses a wearable robot composed of a band, a supporter, and a hook-and-loop fastener based on a polyurethane elastic fiber (spandex) fabric. Rotational torque generated by a motor with planetary gears is driven by a wire through a pulley to assist plantar flexion of the ankle joint during walking.

Patent Literature 2 discloses an assist device that connects the waist and knees of the wearer with a coil-shaped telescopic actuator called a McKibben actuator, and assists the front and rear muscles of the thigh.

JP 2009-213538 A JP 2018-83275 A

Alan T. Asbeck, Stefano M.; M. De Rossi, Ignacio Galiana, Ye Ding, and ConorJ. Walsh, "Stronger, Smarter, Softer: Next Generation Wearable Robots," IEEE Robotics and Automation Magazine, vol. 21, no. 4, pp. 22-33, 2014.

However, the assist device using the conventional soft actuator has the following problems in terms of compatibility with the wearer. First, in the technique of Non-Patent Document 1, the weight of the entire system is about 5.5 kg, and the control unit including the actuator is externally installed. rice field.

In addition, in the technique of Patent Document 2, since the coil-shaped actuator is laid on the buttocks when the user is seated, although the actuator itself can be prevented from being damaged, the wearer may feel discomfort or, in some cases, pain when the wearer is seated. There was a concern that

An assist device according to an aspect of the present disclosure includes one or more contraction-type inflatable actuators that contract in one direction due to inflow of air, and one or more contraction-type inflatable actuators that cause air to flow into or out of the contraction-type inflatable actuator. and a controller unit that controls the inflow and outflow of the air in accordance with the posture of the wearer , wherein the contraction type inflatable actuator is arranged so that one end in the contraction direction is directed toward the wearer. and the other end in the retraction direction is fixed directly or indirectly to a position corresponding to the lower part of the patella of the wearer, and at least the inflatable actuator for extending the right knee joint and the left It has an inflatable actuator for extending the knee joint, an inflatable actuator for flexing the right knee joint, and an inflatable actuator for flexing the left knee joint. The inflatable actuator for extending the left knee joint is positioned at a position corresponding to the front side of the left thigh of the wearer, and the inflatable actuator for bending the right knee joint is positioned at a position corresponding to the rear side of the right thigh of the wearer. The inflatable actuators for flexing the left knee joint are provided at positions corresponding to the rear side of the wearer's left leg thigh, and further comprise inflatable inflatable actuators that expand in the thickness direction due to inflow of air. The inflatable actuator is characterized by being directly or indirectly fixed to a position corresponding to the buttocks of the wearer.

The shrinkable inflatable actuator has an inflatable structure in which the peripheries of two deformable sheets are bonded together in a sealed state, and the inside thereof is partially bonded together in an air-permeable state to form a plurality of small sheets. It may be formed by division into vesicles.

The contraction type inflatable actuator has a substantially rectangular planar structure, and may be divided into a plurality of vesicles parallel to the short sides.

The expansion type inflatable actuator may be a pair of inflatable structures each having a substantially circular planar shape.

The controller provides a phase for inflowing air into the inflatable inflatable actuators when the wearer starts to stand up, and after detection of a target motion, injects air from the inflatable inflatable actuators into the contracting inflatable actuators for extending the left and right knee joints. may be sequentially executed.

A valve connected between the pump and the expansion inflatable actuator or the contraction inflatable actuator via an air tube is used to control the inflow and outflow of air to and from the expansion inflatable actuator and the air inflow to the contraction inflatable actuator. may be controlled by switching the valves of

According to the walking motion of the wearer, the controller controls a phase in which the contracting inflatable actuator for extending the right knee joint flows air into the contracting inflatable actuator for bending the right knee joint, and a phase for flexing the right knee joint. a phase of flowing air from the contracting inflatable actuator into the contracting inflatable actuator for right knee extension; and a phase of flowing the air of the contracting inflatable actuator for flexing the left knee joint into the contracting inflatable actuator for extending the left knee joint.

An assist garment according to an aspect of the present disclosure is provided with the assist device.

An assist control program according to an aspect of the present disclosure is a program executed by the controller, and includes a step of causing air to flow into the inflatable inflatable actuator when the wearer starts a standing motion, and a step of verifying the motion. and, when a target motion is detected, directing the air of the inflatable inflatable actuator to the contracting inflatable actuators for left and right knee extension.

An assist control program according to an aspect of the present disclosure is a program executed by the controller, wherein the air of the contracting inflatable actuator for right knee extension is transferred to the contracting inflatable actuator for right knee flexion. introducing air from the right knee flexion contraction inflatable actuator into the right knee extension contraction inflatable actuator; and introducing air from the left knee extension contraction inflatable actuator. circulating the steps of flowing air into the contracting inflatable actuator for left knee joint flexion, and flowing air from the contracting inflatable actuator for left knee joint bending into the contracting inflatable actuator for left knee extension. execute

According to one aspect of the present disclosure, it is possible to assist from a sitting state to standing up and even walking with a lightweight and comfortable wearing.

1 is a conceptual diagram of an assist device according to a first embodiment of the present disclosure; FIG. 1 is a perspective view of a retractable inflatable actuator according to a first embodiment of the present disclosure; FIG. Photograph of a contraction type inflatable actuator prototype according to the first embodiment of the present disclosure Photograph of the contracted inflatable actuator prototype according to the first embodiment of the present disclosure when mounted Conceptual diagram of an assist device according to a second embodiment of the present disclosure Map showing the load distribution of the buttocks when the wearer is seated Photograph of an inflatable inflatable actuator prototype according to the second embodiment of the present disclosure Block diagram of an assist device according to the second embodiment of the present disclosure FIG. 7 is an image diagram showing a change in posture of a wearer of the assist device according to the second embodiment of the present disclosure from a sitting state to a standing state; Flowchart of a program executed by a controller of an assist device according to a second embodiment of the present disclosure FIG. 7 is a block operation diagram showing switching of valves from a seated state to a standing state of the assist device according to the second embodiment of the present disclosure; FIG. 5 is a conceptual diagram showing the flow of air in the assist device according to the second embodiment of the present disclosure; A conceptual diagram showing the effect of the assist device of the second embodiment of the present disclosure. FIG. 11 is a conceptual diagram showing the flow of air in the assist device according to the third embodiment of the present disclosure; FIG. 11 is a block diagram showing switching of valves immediately before walking motion of the assist device according to the third embodiment of the present disclosure; FIG. A block diagram showing switching of a valve in a walking state of an assist device according to a third embodiment of the present disclosure A block diagram showing switching of a valve in a walking state of an assist device according to a third embodiment of the present disclosure Graph showing experimental results of Example 2 of the present disclosure FIG. 10 is a perspective view of a contraction-type inflatable actuator according to a second embodiment of the present disclosure; Graph showing experimental results of Example 2 of the present disclosure A photograph showing the mounting position of the sensor in the experiment of Example 3 of the present disclosure Graph showing experimental results of Example 3 of the present disclosure Timing chart showing operation of Example 4 of the present disclosure Graph showing experimental results of Example 4 of the present disclosure Graph showing experimental results of Example 5 of the present disclosure Graph showing experimental results of Example 5 of the present disclosure Graph showing experimental results of Example 6 of the present disclosure Graph showing experimental results of Example 6 of the present disclosure Graph showing experimental results of Example 6 of the present disclosure

Hereinafter, an embodiment (hereinafter referred to as a first embodiment) according to one aspect of the present disclosure will be described in detail with reference to the drawings. FIG. 1 shows a conceptual diagram of the assist device of the first embodiment. In FIG. 1, the assist device 1 has a shape such that it can be worn on a trouser-like garment 5. As shown in FIG. Reference numeral 2 denotes a pair of contraction type inflatable actuators (contraction type IfA) that contract in one direction by inflow of air, and in this embodiment, a pair of left and right actuators are provided. A controller unit 100 includes one or more pumps for inflowing or outflowing air through an air tube 201 to the retractable inflatable actuator 2, and a controller for switching between inflow and outflow of the air according to the posture of the wearer. (not shown).

FIG. 2 shows a perspective view of the retractable inflatable actuator 2 according to this embodiment. The retractable inflatable actuator 2 forms an inflatable structure in which two deformable sheets are adhered in a hermetically sealed manner except for the connecting portion with the air tube 201 . Furthermore, the inside of the vesicles is divided into a plurality of vesicles by partially pasting them together in an air-permeable state. In this embodiment, as shown in FIG. 2, it has a substantially rectangular planar structure and is divided into a plurality of vesicles parallel to the short sides. In the present embodiment, the term "substantially rectangular" includes not only a geometric rectangular shape, but also a rectangular shape with rounded corners and a rectangular shape with connection projections.

When air is allowed to flow into the retractable inflatable actuator 2 (ON in FIG. 2), the retractable inflatable actuator 2 as a whole expands in the thickness direction, but contracts in the longitudinal direction (perpendicular to the dividing line). transform. When the air is let out (OFF in FIG. 2), the original sheet shape is restored. The relationship between the amount of inflow of air and the amount of shrinkage will be described in detail in a second embodiment.

In this embodiment, the retractable inflatable actuator 2 has its upper end in the retracting direction connected via a wire 13 to a band 11 provided on the wearer's thigh. In addition, the lower ends are respectively connected via wires 14 to a band 12 provided directly below the patella of the wearer. Two wires 14 may be provided so as to bypass the patella. Also, the wire 13 may also be composed of two wires for matching with the wire 14 . The wires 13 and 14 do not need to be provided independently, and may be integrally formed with the contraction type inflatable actuator 2. FIG. Also, if the length of the retractable inflatable actuator 2 is equivalent to the length of the wearer's thigh, it may be directly connected to the band 11 or the band 12 without using the wire 13 or the wire 14 . Also, the bands 11 and 12 may be sewn into the clothes 5 worn by the wearer as reinforcing materials.

FIG. 3 shows a photograph of the prototype of the contractile inflatable actuator 2 according to the present embodiment (left is when air is flowing out, right is when air is flowing), and FIG. Shown is a photograph when worn so as to be positioned at. The prototype uses a thermoplastic polyurethane (TPU) film. Since TPU has the properties of being more stretchable and more resistant to tearing than polyethylene, it can prevent rupture when it expands excessively. Two TPU films are superimposed and heat-sealed so that they are longitudinally divided into vesicles. In addition, in order to ensure air permeability between the vesicles, the central portion of the vesicle dividing wall is masked in advance so as not to be thermally welded.

In the case of FIG. 4, the contraction type inflatable actuator 2 has a function of assisting the wearer's front thigh muscles (quadriceps). That is, when the wearer performs an operation to extend the knee (knee joint extension operation), the quadriceps femoris muscle is contracted. can be done. In addition, since the retractable inflatable actuator 2 is formed by pasting two thermoplastic sheets together, it is lightweight and flexible, and can be worn by the wearer without feeling discomfort, and can be sewn into clothing. becomes. In addition, contracting inflatable actuators can be placed on the front and back of the thigh to act as extensor and flexor muscles, respectively.

A second embodiment of the present disclosure will be described below. FIG. 5 is a conceptual diagram of the assist device 1 according to the second embodiment of the present disclosure. In FIG. 5, 21a, 21b, 22a, and 22b are contraction type inflatable actuators for right knee joint extension, left knee joint extension, right knee joint flexion, and left knee joint flexion, respectively. It has a function equivalent to that of the contraction type inflatable actuator 2 in the form of . Contraction type inflatable actuators 21a and 21b for extension are placed on the front of the wearer and connected to the thigh band 11 and the lower patella band 12 via wires, respectively. Also in the present embodiment, it is assumed that a pair of left and right bands 11 and 12 are provided. As in the first embodiment, the wire may be integrally formed with the contraction inflatable actuator, or the contraction inflatable actuator may be directly connected to the band 11 or band 12 without using the wire. Also, the bands 11 and 12 may be sewn into the clothes 5 worn by the wearer as reinforcing materials.

Contraction type inflatable actuators 22a and 22b for bending are provided on the rear surface of the wearer and similarly connected to bands 11 and 12 via wires (or directly connected without using wires). In addition, air flows from the controller unit (100) to each of the contraction type inflatable actuators 21a, 21b, 22a, 22b via air tubes 201a, 201b, 202a, 202b. In FIG. 5, the controller unit is shown (with broken lines) as if it were also provided on the rear surface of the wearer, but air tubes may be piped from one controller unit 100 to the front and rear.

Furthermore, in FIG. 5, 3a and 3b are expansion type inflatable actuators that expand in the thickness direction when air flows in. As shown in FIG. The inflatable inflatable actuators 3a and 3b are indirectly fixed to the buttocks so as to be placed at the left and right buttocks of the wearer, respectively. As a fixing method, it may be connected to a waist or thigh band, or may be directly fixed to the clothes 5 worn by the wearer.

It is assumed that the expansion type inflatable actuators 3a and 3b each have a substantially circular planar shape. Here, the term "substantially circular" means not only a true circle but also an ellipse close to a new circle, a broad bean-like closed curve figure, and a polygon close to a perfect circle, preferably octagonal or more. FIG. 7 shows a photograph of a prototype of the expansive inflatable actuator according to the second embodiment of the present disclosure. The prototype uses a thermoplastic polyurethane (TPU) film. It is formed by stacking two substantially circular TPU films and welding the outer periphery except for the air inflow (outflow) port.

The reason why the inflatable inflatable actuators 3a and 3b are preferably substantially circular is that, as shown in FIG. Due to the fact that Therefore, for example, if the circular inflatable inflatable actuators 3a and 3b (solid lines in the figure) are arranged with respect to the buttocks of the wearer so that the part where the pressure is the highest is almost at the center, the operation during standing (described later) ( 13) can be supported more stably. The assisting operation at the time of standing up will be sequentially described below.

FIG. 8 shows a control block diagram of the assist device of this embodiment. In FIG. 8, contraction type inflatable actuators 21a, 21b, 22a, 22b and expansion type inflatable actuators 3a, 3b symbolize those shown in FIGS. 3 and 7, respectively. 8, controller unit 100 includes valves 41a, 41b, 42a, 42b, 43a, 43b and pumps 50a, 50b, 53, and controller 101. In FIG. Further, the controller unit 100 includes a power supply 71, switches 72, 76, DCDC converters 74, 75, junctions 73, 60a, 60b, 63. The controller 101 has six output ports, which switch the valves 41a, 41b, 42a, 42b, 43a, 43b via the NPN transistors 102, respectively.

The pump 50a causes air to flow into or out of the contraction inflatable actuator 21a (for extension), the contraction inflatable actuator 22a (for bending), and the expansion inflatable actuator 3a arranged on the right side according to the phase. The pump 50b causes air to flow into or out of the contraction inflatable actuator 21b (for extension), the contraction inflatable actuator 22b (for bending), and the expansion inflatable actuator 3b arranged on the left side depending on the phase. A pump 53 draws air into the expansion inflatable actuators 3a, 3b. The pumps 50a, 50b, 53 simultaneously perform the intake and outflow of air, and whether the air is inflow or outflow to each inflatable actuator is controlled by the valves 41a, 41b, 42a, 42b under the direction of the controller 101. , 43a, 43b.

FIG. 10 shows a flowchart of a program executed by the controller 101 of the assist device according to the second embodiment of the present disclosure when the standing action shown in FIG. 9 is performed. First, the pump 53 is turned on to introduce air into the expansion type inflatable actuators 3a and 3b (S1). After that, motion verification is performed (S2), and if the target motion is detected (S3), the process proceeds to the next step. The above steps correspond to the phase (phase 1) in the standing motion (FIG. 9). Here, the target motion means the motion of leaving the chair and slightly crouching, and the maximum flexion of the hip joint is detected at this time. This maximum hip joint flexion can be detected, for example, by providing a bending sensor or the like near the knee of the clothing 5, but an angular acceleration sensor or a biopotential sensor may also be used. Details of operation verification and target operation will be described again in the third and sixth embodiments.

When the target motion is detected, the pump 53 is turned off, and instead the pumps 50a and 50b are turned on. At the same time, the valves 43a and 43b are turned on (S4). The above operation corresponds to the phase (phase 2) in the standing operation (FIG. 9). FIG. 11 schematically shows the state of the assist device at the end of phase 1 ((a) in the same figure) and the state of the assist device in phase 2 ((b) in the same figure). In phase 2, a flow path is formed through which air flows from the expansion inflatable actuator 3a to the contraction inflatable actuator 21a via the valve 43a, the pump 50a, and the valve 41a. As a result, the high-pressure air filling the expansion inflatable actuator 3a is further pressurized by the pump 50a and flows into the contraction inflatable actuator 21a (dotted line arrow in the figure). Similarly, the air filling the expanding inflatable actuator 3b flows through the pump 50a into the contracting inflatable actuator 21b.

As described above, by switching the flow path, the air pressure filled in phase 1 can be used to flow air into the contraction type inflatable actuator in phase 2 (FIG. 12). As a result, standing support with high energy efficiency can be realized. FIG. 13 shows an example of standing support. First, in phase 1, expansion of the expandable inflatable actuators 3a and 3b assists the movement of the user to get off the floor (upward movement of the center of gravity). to support When the standing is completed, all the pumps are stopped (S5).

In this embodiment, controller 101 is a microprocessor, and the flowchart of FIG. 10 may be executed by that program. Also, the program may be preinstalled in a non-volatile memory, or may be downloaded from a server via a communication line.

A third embodiment of the present disclosure will be described below. In the present embodiment, a walking motion support function will be described. First, Table 1 shows assist phases in the present embodiment. Table 2 shows the states of the contraction type inflatable actuators 21a, 21b, 22a, and 22b (Right ex. IfA, Right fl. IfA, Left ex. IfA, and Left fl. IfA in Table 2, respectively) in each phase. . Further, the operation of the contraction type inflatable actuator in this state is schematically shown in FIG. 14, and the ON/OFF states of the pneumatic control device are shown in FIGS. In this embodiment, the expansion type inflatable actuators 3a and 3b are not operated.

In the present embodiment, "Neutral (phase)" means a phase in which no assist is performed, such as a two-leg support phase or a stationary phase. At this time, all the contraction type inflatable actuators are not driven although they are slightly filled with air (Fig. 15). Here, when the wearer starts walking, the following phases are sequentially and cyclically executed.

The first phase (R-Flexion phase) is the state from the initial swing to the middle swing when the knee joint of the right leg is flexed (FIG. 16(a)). At this time, the air in the inflatable actuator 21a for supporting the extension of the right knee joint is sent by the pump 50a to the contracting inflatable actuator 22a for supporting the bending of the right knee joint. As a result, the retractable inflatable actuator 22a for supporting bending of the right knee joint performs a contracting operation, and the retractable inflatable actuator 21a for supporting bending is completely deflated and fully expanded. At this time, since the pair of legs are supporting legs, the retractable inflatable actuators 21b and 22b of the pair of legs are in a neutral state.

The next phase (R-Extension phase) is the state from the mid-swing period in which the knee joint of the right leg is extended to the initial contact (FIG. 16(b)). At this time, the air in the inflatable actuator 22a for assisting in bending the right knee joint is sent by the pump 50a to the contracting inflatable actuator 21a for assisting in extending the right knee joint. As a result, the retractable inflatable actuator 21a for supporting the extension of the right knee joint contracts, and the inflatable actuator 22a for supporting the bending of the right knee joint is in a fully expanded state due to the release of air. The opposite leg retractable inflatable actuators 21b, 22b are still in the neutral state.

The L-Flexion phase ((FIG. 17(a))) and L-Extension phase ((FIG. 17(b))) of the left leg are the same as the Flexion phase and Extension phase of the right leg, respectively, so the description is omitted. . The switching timing of each phase will be described in a sixth embodiment. In this embodiment, the switching operations of Tables 1 and 2 may be executed by a program of controller 101 (microprocessor). Also, the program may be preinstalled in a non-volatile memory, or may be downloaded from a server via a communication line.

As described above, according to the above embodiment, it is possible to support the wearer in standing up and walking with a lightweight mechanism. Furthermore, while the wearer is seated, the expandable inflatable actuator for assisting standing up is deflated into a sheet-like shape, so there is almost no sense of discomfort when the wearer sits on the seat. Other inflatable actuators are also sheet-like when not in operation, so they are usually worn as "part of clothing" and can be activated only when the muscles are tired or sore.

In the above-described embodiment, the clothes 5 are trouser-like, but they may be jackets such as vests and jumpers. may be used to support

Examples of the present disclosure will be described below.

(Example 1)
In this embodiment, a specific configuration example of the controller unit 100 (see FIG. 8) will be described. First, a lithium ion polymer secondary battery (LiPo) was adopted as the battery 71 . Unlike lithium ion secondary batteries, LiPo does not use a metal can for its outer packaging, so it is compact and lightweight, has a large capacity, and has a relatively long life.

A single board computer (Aidilab: UDOOX86) was used as the controller 101 . The UDOOX86 is equipped not only with the main processor (QuadCore64-bitnew-generationx86Braswell14nm), but also with an ArduinoTM101 compatible module (Intel (registered trademark) CurieTM), allowing easy access to the ArduinoTM101 while using Mac, Windows or Linux (registered trademark). It has the advantage of being able to Braswell and Curie have 20 and 14 digital input/output pins, respectively, which can be set to A/D converter or PWM output.

A brushless DC pump (Nitto Kohki Co., Ltd.: DP0210TA-Y1) was used as an air supply source (pumps 50a, 50b, 53) for driving the inflatable actuator. Despite its light weight of 0.32 kg, it delivers 10 L of air per minute. Because it uses a brushless DC motor, it is easy to maintain and highly efficient. Also, since it is a twin head type with two pistons, vibration during driving is small.

The valves 41a, 41b, 42a, 42b, 43a, and 43b each used a 5-port solenoid valve (SMC: VK3120-5GS-01). Two flow paths are switched, and two inflatable actuators are alternately driven while driving one pump per leg.

The single board computer (controller) is driven by 12VDC, and the pumps 50a, 50b, 53 and valves 41a, 41b, 42a, 42b, 43a, 43b are all driven by 24VDC, so the DCDC converters 74, 75 also output 12VDC respectively. , 24V output is used.

(Example 2)
In this embodiment, a performance evaluation experiment (response, maximum displacement) of a contraction-type inflatable actuator prototype and its results will be described. Using a TPU film with a thickness of 0.07 mm, three types of shrinkable inflatable actuators with different design parameters were prototyped (Table 3). Weights of 0.4 kg, 0.8 kg, and 1.2 kg were hung on them, and they were driven by a DC pump. Measured. The DC pump used was DP0210T (delivered air volume: 10 L/min) manufactured by Nitto Kohki Co., Ltd.

FIG. 18(a) shows the maximum displacement amount with respect to the load of the three types of contraction type inflatable actuators (IfA1, IfA2, IfA3), and FIG. 18(b) shows the respective response times. Comparing IfA1 (L = 160 mm) and IfA2 (L = 80 mm), the longer one has a larger maximum displacement (Fig. 18 (a)), but the response time does not change significantly (Fig. 18 (b)). It turns out. It is considered that the response time largely depends on the amount of air discharged from the DC pump, which is the air supply source. On the other hand, comparing IfA1 (W=70 mm) and IfA3 (W=100 mm), no significant difference was found in the maximum displacement amount, and the response time was slow. From this, it is considered that the contraction type inflatable actuator can model the relationship between the length and the maximum amount of displacement.

Modeling of the maximum displacement amount of the inflatable actuator will be described below. The contraction type inflatable actuator is displaced in the length direction by expanding each vesicle, which is the minimum unit of the inflatable structure, into a cylindric shape (FIG. 19). Therefore, when the length of the major axis of the ellipse is 2a and the length of the minor axis is 2b, the circumference of the ellipse C is represented by the Gauss-Kummer series as the sum of infinite series including the binomial coefficient as follows.

By approximating the formula (3.1) only with the first term, it can be written as follows.

Assuming that the width of each vesicle is l (el), the following equation can be obtained from the relationship of l (el)=C/2.

Further, if the total length of the contractile inflatable actuator is L, the number of vesicles (division number) is m, and the seal width at the time of thermal welding is s, the width of each vesicle is expressed as follows.

Here, the displacement amount Δd per element can be expressed by the following equation.

Ｌ、ｍ、ｓは設計パラメータであり、収縮型インフレータブルアクチュエータの設計時に一意に決定する定数である。すなわち最大変位量ΔＤは駆動時の収縮型インフレータブルアクチュエータの厚さｂ（楕円近似したときの短軸の長さ）のみに依存し、ｂは荷重の大きさに依存する。 Therefore, the maximum displacement amount ΔD is obtained by the following equation.

L, m, and s are design parameters, constants uniquely determined when designing the contraction type inflatable actuator. That is, the maximum displacement amount ΔD depends only on the thickness b (the length of the minor axis of the elliptical approximation) of the retractable inflatable actuator during driving, and b depends on the magnitude of the load.

In order to compare this calculation formula of the maximum displacement amount with the actual maximum displacement amount, the maximum displacement amount and the thickness of the contraction type inflatable actuator at that time were similarly measured. Weights of 0.4 kg, 0.8 kg, 1.2 kg, 1.6 kg, and 2.0 kg were suspended from contraction-type inflatable actuators with 8 elements (number of vesicles), 70 mm width, and 160 mm length. It was driven to rotate (contraction motion). First, FIG. 20(a) shows a graph of the measured thickness of the contraction-type inflatable actuator when the displacement is maximized. It was confirmed that the thickness monotonously decreased as the magnitude of the load increased. Further, the calculated value (Equation 3.11) of the maximum displacement obtained from this thickness and the actual measured value are shown in FIG.

From the above results, it was confirmed that both the calculated and measured values of the maximum displacement decreased monotonously when the load was increased. That is, by using equation (3.11), the design parameters of the contraction-type inflatable actuator can be easily determined based on the required amount of assistance (load on the lower leg). Although there are some errors between the calculated values and the measured values, these errors include errors in the prototype stage and measurement deviations.

(Example 3)
In this embodiment, an experiment and the results of the standing-up motion will be described. In the first embodiment, switching from Phase 1 to Phase 2 is assumed to be performed when a target motion is detected, and the target motion is the maximum flexion of the hip joint when standing up from the floor. Therefore, in this embodiment, a nine-axis measurement system called AHRS (Attitude Heading Reference System) consisting of an acceleration sensor, an angular velocity sensor and a magnetic sensor was used to detect the maximum flexion of the hip joint.

By attaching the AHRS to the waist, right thigh, left thigh, right lower leg, and left lower leg (Fig. 21), the left and right hip joint angles and knee joint angles could be measured. FIG. 22 shows actually measured hip joint angles when standing up and timing signals for target motion detection. Based on this timing signal, switching from Phase1 to Phase2 is performed (see FIG. 10).

(Example 4)
In the present embodiment, an experiment of assistance during walking and its results will be described. One subject (healthy male, 23 years old) wore a total of five AHRSs on the waist, thighs and lower legs (Fig. 21), and walked on a treadmill at a comfortable walking speed of 4 km/h. In order to confirm that the extreme value of the knee joint angle is properly detected, a flag is set at the timing when the assist phase is switched. Furthermore, in order to confirm that the contraction type inflatable actuators are actually alternately driven according to the flexion and extension of the knee joint, the internal pressure of the two contraction type inflatable actuators was measured by an air pressure sensor (manufactured by NXPUSA Inc.: MPXV5010GC7U). The same experiment was conducted while measuring using

FIG. 23 shows the right knee joint angle and three assist phase flags of R-Flexion, R-Extension and Neutral (third embodiment, see Table 2). It was confirmed that the three assist phase flags were set at the timing when the extreme value of the knee joint angle was detected.

Further, FIG. 24 shows the right knee joint angle and the internal pressure of the flexing (Flexer) contraction inflatable actuator (22a or 22b) and the extension (Extensor) contraction inflatable actuator (21a or 21b). After switching to the R-Extensionphase (around 43.2 seconds), it was confirmed that the internal pressure of the bending IfA decreased and the internal pressure of the extension inflatable actuator increased after about 0.1 seconds. It is shown that immediately after the contraction type inflatable actuator is driven, air flows in with a change in volume, so the internal pressure increases gently, and after the volume reaches its maximum, the internal pressure rises sharply.

On the other hand, in Neutralphase, the DC pump is not driven, and the air in the contraction inflatable actuator for extension flows into the (Flexer) contraction inflatable actuator for flexion according to the pressure gradient. It takes time for the internal pressure of the inflatable actuator to start decreasing. However, when the inflatable actuator is actually installed, it is thought that the inflow and outflow of air will occur more quickly due to the application of the load. In the Neutralphase, air already remains in the contraction inflatable actuator for bending, so even when entering the R-Flexionphase, the internal pressure of the contraction inflatable actuator for bending does not change significantly. However, since the internal pressure of the contraction-type inflatable actuator for extension is rapidly reduced, it can be estimated that IfA for flexion is appropriately driven.

(Example 5)
In this example, experiments on a prototype of the expansion type inflatable actuator (3a or 3b) and the results thereof will be described. The prototype had a circular planar shape, and three types with diameters of 20 cm, 16 cm, and 12 cm were prepared. The internal pressure was represented by a gauge pressure, which is the difference from the atmospheric pressure, and a gauge pressure sensor capable of measuring from 0 kPa to 10 kPa was used. A pump manufactured by Nitto Kohki Co., Ltd. (air flow rate: 10 L/min, 24 VDC) was used.

FIG. 25(a) shows changes in the internal pressure of the Φ20 cm expansion inflatable actuator. Air inflow was started at about 3 seconds. Immediately after the start, the internal pressure increased rapidly, then became constant at about 2 kPa, and increased again around 10 seconds. Such a change is considered to be due to plastic deformation of the expansive inflatable actuator due to volume expansion. From this, it can be said that the range in which the internal pressure is constant from the start of air inflow is the air inflow amount that can be safely used without causing plastic deformation of the expansion inflatable actuator.

As the diameter of the inflatable inflatable actuator decreases to Φ16 cm and Φ12 cm, the range in which the internal pressure is constant tends to narrow ((b) and (c) in the figure). Although not shown, in the Φ10 cm inflatable inflatable actuator, there was almost no range in which the atmospheric pressure remained constant, and the pressure suddenly reached 10 kPa, which is the upper limit of the prepared gauge pressure sensor.

FIG. 26 shows the results of the load test of the expansion inflatable actuator. An inflatable inflatable actuator with each diameter was placed between two plates, weights of 0.7 kg, 5 kg, 10 kg, 15 kg, 20 kg, 25 kg, and 30 kg were placed on the upper plate, and measurements were taken three times each. After the experiment was completed, it was confirmed that there was no rupture or plastic deformation. As shown in the figure, the larger the diameter, the higher the lift.

(Example 6)
In this embodiment, an electromyograph is used to describe a standing-up motion measurement experiment and its results. As shown in FIG. 9, the standing motion from a sitting posture includes a motion phase (Phase 1) in which the center of gravity is moved forward by tilting the trunk forward when sitting, and a motion phase (Phase 1) in which the lower limb joints are extended and the center of gravity is moved forward when the buttocks leave the floor. It can be classified into an operation phase (Phase 2) that moves upward. In particular, in this embodiment, it is verified whether muscle activity in Phase 2 changes due to the difference in seat height in Phase 1.

In this example, stands of 30 cm, 40 cm, and 50 cm were prepared, and the standing motion was measured five times for each height. Inertial motion capture (MVNAwinda, manufactured by Xsens Technologies) was used to measure the motion, and the hip/knee/ankle joint angles and the lumbar back-and-forth direction and vertical acceleration were measured. In addition, using a wireless electromyograph (MiniWave manufactured by COMETA Systems), electrodes were attached to the left and right rectus femoris and vastus lateralis muscles, and muscle activity (electromyography: abbreviated as EMG) was measured from biopotential signals during standing. bottom. A root mean square (RMS) was calculated from the obtained EMG, and an integrated EMG (iEMG) was calculated.

Lower limb joint angle data when standing up under different conditions of seat heights of 30 cm, 40 cm, and 50 cm, iEMG calculated from biosignals of the rectus femoris and vastus lateralis, and acceleration data in the anteroposterior and vertical directions of the waist are shown in FIGS. 27(a), (b) and (c). Similarly, results from other subjects are shown in Figures 28(a), (b), and (c). In both cases, an increase in the iEMG of the rectus femoris and vastus lateralis was confirmed during large flexion. At this time, it was confirmed that the waist acceleration in the longitudinal and vertical directions increased in the forward and upward directions.

FIGS. 29(a) and 29(b) show the RMS value of the biopotential signal under each seating condition for each subject. As is clear from the figure, it was confirmed that the RMS values generated in the rectus femoris muscle and vastus lateralis muscle during standing tended to decrease as the seat height increased. In addition, statistically significant differences (p<0.01, p<0.05) were observed.

The iEMG of the rectus femoris muscle and vastus lateralis muscle increased during the transition from Phase 1 to Phase 2. It can be considered that the anti-gravity movement, which is the knee joint extension exercise, was performed by both muscle groups immediately after the hip lifted off the floor. . Therefore, there is an extremely high need to support the knee joint extension exercise when getting out of bed when transitioning from Phase 1 to Phase 2 occurs. Also, the reason why the acceleration in the front-rear direction of the waist increased in the forward direction is considered to be that the center of gravity of Phase 1 moved forward. It is considered that the vertical acceleration increased upward because the center of gravity of Phase 2 started to move upward. After that, the downward acceleration increased. From the above, it is possible to estimate the time of leaving the bed by using the waist acceleration information.

In addition, FIGS. 29(a) and 29(b) show that the RMS values of the rectus femoris muscle and vastus lateralis muscle decrease as the height of the seat increases. The main cause of the RMS value change due to the difference in the seat height is the difference in the initial posture in Phase1. As the seat surface position becomes higher, the center of gravity in the initial posture is also distributed at a higher position, and the moving distance of the center of gravity becomes shorter in Phase 2 from leaving the floor to standing posture. It can be considered that these factors changed the amount of muscle activity of the rectus femoris and vastus lateralis.

Based on the above, we believe that Phase 1 requires an inflatable inflatable actuator that assists the upward movement of the center of gravity before the buttocks leave the floor, and Phase 2 requires a retractable inflatable actuator that assists the extension of the knee joint after the hips leave the floor. be done.

INDUSTRIAL APPLICABILITY The present invention can be used to assist the daily living of elderly people with weakened muscles and sick people. In addition, even for healthy people, it may be used for the purpose of reducing muscle fatigue in technical work and sports such as mountain climbing, which involve many standing and sitting movements.

1 assist device 2 contraction type inflatable actuator
3a, 3b inflatable inflatable actuator 5 garments 11, 12, 13 bands 21a, 21b, 22a, 22b deflated inflatable actuator
41a, 41b, 42a, 42b, 43a, 43b valves 50a, 50b, 53 pump 100 controller unit 101 controller 201 air tubes 201a, 201b, 202a, 202b air tubes 302a, 302b air tubes

Claims (10)

One or a plurality of contraction inflatable actuators that contract in one direction due to inflow of air; one or a plurality of pumps that cause air to flow in or out of the contraction inflatable actuator; and a controller unit comprising a controller for controlling the inflow and outflow of air ,
The contraction type inflatable actuator is directly or indirectly fixed with one end in the direction of contraction at a position corresponding to the wearer's thigh and the other end in the contraction direction at a position corresponding to the lower part of the wearer's patella. and at least a right knee joint extension inflatable actuator, a left knee joint extension inflatable actuator, a right knee joint flexion inflatable actuator, and a left knee joint flexion inflatable actuator,
The inflatable actuator for extending the right knee joint is placed at a position corresponding to the front side of the wearer's right leg thigh, and the inflatable actuator for left knee joint extension is placed at a position corresponding to the front side of the wearer's left leg thigh. The inflatable actuator for knee joint bending is provided at a position corresponding to the rear side of the wearer's right leg thigh, and the left knee joint bending inflatable actuator is provided at a position corresponding to the rear side of the wearer's left leg thigh. be
Further, an assist device comprising an inflatable inflatable actuator that expands in a thickness direction due to inflow of air, wherein the inflatable inflatable actuator is directly or indirectly fixed to a position corresponding to the buttocks of the wearer. . The shrinkable inflatable actuator has an inflatable structure in which the peripheries of two deformable sheets are adhered in a sealed state, and the inside thereof is partially adhered in an air-permeable state. 2. The assist device according to claim 1, wherein the assist device is divided into cells. 3. The assist device according to claim 2, wherein the contraction type inflatable actuator has a substantially rectangular planar structure, and is divided into a plurality of vesicles parallel to the short sides. 4. The assist device according to any one of claims 1 to 3, wherein the expansion type inflatable actuator is a pair of inflatable structures each having a substantially circular planar shape. The controller provides a phase for inflowing air into the inflatable inflatable actuators when the wearer starts to stand up, and after detection of a target motion, injects air from the inflatable inflatable actuators into the contracting inflatable actuators for extending the left and right knee joints. 5. The assist device according to any one of claims 1 to 4 , characterized in that the phases of inflowing into are sequentially executed. The inflow and outflow of air to and from the inflatable inflatable actuator for knee extension and the inflow and outflow of air to the inflatable knee extension actuator are controlled by air flow between the pump and the inflatable inflatable actuator or the retractable inflatable actuator for knee extension. 6. The assist device according to claim 5 , wherein the assist device is controlled by switching a valve connected via a tube. According to the wearer's walking motion, the controller
a phase of flowing air from the contracting inflatable actuator for right knee extension into the contracting inflatable actuator for right knee flexion;
a phase in which the air of the contracting inflatable actuator for flexing the right knee joint flows into the contracting inflatable actuator for extending the right knee joint;
a phase of flowing air from the contracting inflatable actuator for left knee extension into the contracting inflatable actuator for left knee flexion;
7. The assist according to claim 6 , characterized in that a phase of flowing air of said contracting inflatable actuator for left knee joint flexion into said contracting inflatable actuator for left knee extension is cyclically executed. Device. An assisting garment provided with the assisting device according to any one of claims 1 to 7 . An assist control program executed by the controller of the assist device according to claim 5 ,
allowing air to flow into the inflatable inflatable actuator when the wearer begins to stand up ;
verifying operation ; and
and C. when a target motion is detected, directing air from the inflatable inflatable actuator to the contracting inflatable actuators for left and right knee extension. An assist control program executed by the controller of the assist device according to claim 7 ,
allowing air in the right knee extension contracting inflatable actuator to flow into the right knee flexing contracting inflatable actuator;
directing air from the contracting inflatable actuator for right knee flexion into the contracting inflatable actuator for right knee extension;
allowing air in the inflatable left knee joint extension contracting actuator to flow into the contracting inflatable actuator for left knee flexion;
and a step of cyclically executing the step of causing the air of the contracting inflatable actuator for left knee joint flexion to flow into the contracting inflatable actuator for left knee extension.

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