Controller and control method for walking movement assisting device

Abstract

To provide a walking movement assisting technology capable of reducing discomfort of a user when actually walking and realizing stable walking.SOLUTION: A controller for a walking movement assisting device comprises: means for acquiring present phase information capable of specifying a present phase in one walking cycle of a target leg of a user; and control processing means for controlling drive of a drive mechanism by a motor on the basis of the present phase information. The control processing means can, on the basis of the present phase information, execute plantar flexion control that makes the drive mechanism rotate in a plantar flexion direction and dorsal flexion control that makes the drive mechanism rotate in a dorsal flexion direction, and executes free control for setting the drive mechanism to a free state in one or both of a first section which is at least a portion during the present phase information showing a phase corresponding to a sole grounding phase during the one walking cycle and a second section which is at least a portion during the present phase information showing a phase corresponding to a swing phase during the one walking cycle.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a walking motion assist device capable of assisting a user's rotational movement of ankle joints. [Background technology]

[0002] Attempts have been made to facilitate walking training by having a user wear a walking motion assist device on his or her legs. The following Patent Document 1 proposes a walking motion assist device that assists the wearer in rotating the ankle joint of the wearer by including a drive motor and a drive mechanism that can rotate coaxially with the ankle joint by the drive motor, etc. In this walking motion assist device, the drive of the drive motor is controlled based on a motion pattern that represents a time-series change in the ankle joint angle in a walking cycle and is represented by a broken line, a Bezier curve, or a combination of these, with a predetermined number of points as bending points. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-217039 A Summary of the Invention [Problem to be solved by the invention]

[0004] In walking motion assistance technology, an important issue is how to achieve stable walking without pain. Through trial and error, the inventors have discovered that excessive assistance in assisting the rotational movement of the user's ankle joint can have the opposite effect of making the user feel uncomfortable or causing unnecessary movement.

[0005] The present invention has been made in consideration of the above circumstances, and provides a walking motion assistance technology that can reduce the discomfort felt by a user when actually walking and achieve efficient and stable walking. [Means for solving the problem]

[0006] One aspect of the present invention is a control device for controlling a walking motion assist device including at least a motor and a drive mechanism that can rotate by the drive force of the motor to assist the rotational motion of the ankle joint of a target leg of a user. The control device according to this aspect includes an acquisition means for acquiring current phase information capable of identifying a current phase of the target leg in one walking cycle, and a control processing means for controlling driving of the drive mechanism by the motor based on the current phase information, and the control processing means is capable of performing plantar flexion control for rotating the drive mechanism in a plantar flexion direction and dorsiflexion control for rotating the drive mechanism in a dorsiflexion direction based on the current phase information, and performs free control to set the drive mechanism in a free state in one or both of a first section that is at least a part of the period during which the current phase information indicates a phase corresponding to a sole-contact state in a stepping cycle, or a second section that is at least a part of the period during which the current phase information indicates a phase corresponding to a swing leg state in a stepping cycle.

[0007] One aspect of the present invention is a walking motion assist method executed by a walking motion assist device including a motor, a drive mechanism capable of rotating by the drive force of the motor to assist the rotational movement of the ankle joint of a target leg of a user, an acquisition means for acquiring current phase information capable of identifying a current phase in one walking cycle of the target leg, and a control processing means for controlling driving of the drive mechanism by the motor based on the current phase information. The walking motion assist method according to one aspect includes the control processing means executing plantar flexion control for rotating the drive mechanism in a plantar flexion direction and dorsiflexion control for rotating the drive mechanism in a dorsiflexion direction based on the current phase information, and executing free control for putting the drive mechanism in a free state in either or both of a first section which is at least a part of the period during which the current phase information indicates a phase corresponding to a sole-contact state in a stepping cycle or a second section which is at least a part of the period during which the current phase information indicates a phase corresponding to a swing leg state in a stepping cycle.

[0008] Another aspect of the present invention may be a computer program for causing one or more processors provided in the walking motion assistance device to execute the above-mentioned walking motion assistance method, or a recording medium for recording such a computer program. Effect of the Invention

[0009] According to the present invention, a walking motion assistance technique can be provided that can reduce the discomfort felt by a user when actually walking and achieve efficient and stable walking. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing an external appearance of a walking movement assist device according to an embodiment of the present invention; [Diagram 2] 1 is a diagram conceptually showing a hardware configuration of a control system of a walking movement assist device according to an embodiment of the present invention. [Diagram 3] 5A and 5B are schematic diagrams for explaining a rotation angle of a drive mechanism in the embodiment. [Figure 4] FIG. 2 is a diagram conceptually illustrating a software configuration of a control device in the present embodiment. [Diagram 5] FIG. 13 is a diagram showing an example of a walking assistance setting screen. [Figure 6] 11A and 11B are diagrams illustrating examples of standard setting information and customized setting information. [Figure 7] 5 is a flowchart showing an example of the operation of the walking movement assist device according to the present embodiment. [Figure 8] 13A and 13B are diagrams showing modified examples of heel-off reference information and modified examples of standard setting information. [Figure 9] 13 is a graph showing the transition of a specific hip joint angle, knee angle, and ankle joint angle during a step cycle in a first case in which the same able-bodied person walked normally without wearing anything, and in a second case in which the able-bodied person walked five steps while wearing the walking motion assistance device of this embodiment, then removed the device and walked normally. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention (hereinafter, sometimes referred to as the present embodiment) will be described with reference to the drawings. The following embodiment is merely an example, and the present invention is not limited to the configuration of the following embodiment.

[0012] [Walking assistance device] FIG. 1 is a perspective view showing the appearance of a walking motion assist device according to this embodiment, and FIG. 2 is a diagram conceptually showing the hardware configuration of a control system of the walking motion assist device according to this embodiment. As shown in Fig. 1, a walking motion assist device 1 according to this embodiment (hereinafter, may be abbreviated as this device) is composed of a leg attachment part 2 and a waist attachment part 5. The leg attachment part 2 is attached to the leg (part below the knee) of a user (wearer), and the waist attachment part 5 is attached to the waist of the user. In the following description of the device 1, the relative positional relationship of each component is specified using directions such as up-down, front-back, and left-right when the device 1 is worn by a user. That is, the front refers to the abdominal side (front) of the human body, the rear refers to the dorsal side (rear) of the human body, the upper refers to the head side of the human body, and the lower refers to the sole side of the human body.

[0013] The waist mounting portion 5 includes a waist belt 51, a waist storage box 52, and the like. The waist belt 51 is worn by wrapping it around the waist of the user. The waist belt 51 is configured so that the length thereof can be adjusted to fit the thickness of the user's waist, similar to a general trouser belt. The waist storage box 52 is held by the waist belt 51, and stores therein the control device 10, a battery (not shown), and the like.

[0014] The leg attachment portion 2 includes a lower leg brace 21, a foot brace 22, lower leg frames 24A and 24B, foot frames 25A and 25B, a leg storage box 28, and the like.

[0015] The lower leg brace 21 is a brace that is worn by wrapping around the lower leg of the user. The lower leg brace 21 is fixed to a position around the user's knee.

[0016] The foot orthosis 22 is a shoe-like orthosis that is worn by inserting the user's foot inside. The foot orthosis 22 has an instep belt 221 that wraps around and fixes the instep of the foot, and an ankle belt 222 that wraps around from the back of the ankle (towards the heel) to the front of the ankle to fix the ankle, and is worn to restrict the posture of the user's foot.

[0017] In addition, a toe pressure sensor 226 and a heel pressure sensor 227 are provided on the bottom of the foot orthosis 22. The toe pressure sensor 226 is a pressure sensor for detecting the load (pressure) on the toes of a user wearing the foot orthosis 22. The toe pressure sensor 226 is disposed, for example, in an area of ​​the bottom of the foot orthosis 22 that comes into contact with the ball of the user's foot. The heel pressure sensor 227 is a pressure sensor for detecting the load (pressure) on the heel of a user wearing the foot orthosis 22. The heel pressure sensor 227 is disposed, for example, in an area of ​​the bottom of the foot orthosis 22 that comes into contact with the heel of the user.

[0018] There are no limitations on the specific principle or structure of the toe pressure sensor 226 and the heel pressure sensor 227, as long as the electrical characteristics change with pressure. Examples of the electrical characteristics that change with pressure include electrical resistance and capacitance. The toe pressure sensor 226 and the heel pressure sensor 227 are connected so as to be able to transmit detection signals wirelessly or via wire to the control device 10 (input / output I / F 13). In this embodiment, the detection signals are transmitted to the control device 10 via wire.

[0019] The toe pressure sensor 226 and the heel pressure sensor 227 correspond to a detection means capable of detecting a toe-on-ground state, a toe-off-ground state, a heel-on-ground state, and a heel-off-ground state of the target leg of the user (the leg on which the leg attachment unit 2 is attached). However, this detection means is not limited to the configuration of this embodiment, and may be realized by a film-type pressure sensor capable of measuring pressure distribution within a surface. In this case, the toe-on-ground state, toe-off-ground state, heel-on-ground state, and heel-off state can be detected in the pressure distribution state.

[0020] The upper ends of the lower leg frames 24A and 24B are each connected and fixed to the lower leg brace 21, and are arranged to sandwich the user's lower leg from the left and right when the leg attachment part 2 is attached. This prevents the upper ends of the lower leg frames 24A and 24B from moving relative to the lower leg brace 21. Hereinafter, the lower leg frames 24A and 24B will be collectively referred to as the lower leg frame 24, unless a special distinction is required.

[0021] The foot frames 25A and 25B have their lower ends connected and fixed to the foot orthosis 22, and are arranged to sandwich the ankle of the user from the left and right when the leg attachment unit 2 is worn. This prevents the lower ends of the foot frames 25A and 25B from moving relative to the foot orthosis 22. Hereinafter, the foot frames 25A and 25B will be collectively referred to as the foot frame 25, unless a distinction is particularly required.

[0022] The lower end of the lower leg frame 24 and the upper end of the foot frame 25 are rotatably connected to each other by a connecting shaft 26. The connecting shaft 26 is provided so as to be located around the left and right ankles of the user when the leg attachment part 2 is attached. In other words, the connecting shaft 26 is provided so as to be located coaxially with the rotation axis of the user's leg joint when the leg attachment part 2 is attached. This allows the lower leg frame 24 and the foot frame 25 to rotate relatively coaxially with the rotational movement of the user's ankle joint when the leg attachment part 2 is attached.

[0023] The leg housing box 28 is held by the (outer) lower leg frame 24A, and houses therein the motor 30, the drive mechanism 40, a rotation sensor 281, etc.

[0024] The motor 30 receives power from a battery housed in the waist housing box 52 and supplies driving force to the drive mechanism 40. In this embodiment, the motor 30 outputs a rotational driving force, but it may also output a linear driving force. The drive mechanism 40 assists the rotational movement of the ankle joint of the target leg of the user by rotating the foot frame 25 about the connecting shaft 26 relative to the lower leg frame 24 by the driving force from the motor 30. The specific structure of the drive mechanism 40 is not particularly limited as long as it can rotate the foot frame 25 relative to the lower leg frame 24 with the driving force from the motor 30. For example, the drive mechanism 40 may include a drive shaft, a reducer, etc. connected to or integrated with the connecting shaft 26 between the lower leg frame 24A and the foot frame 25A, and may be configured to rotate the foot frame 25 relative to the lower leg frame 24 by reducing the rotational driving force of the motor 30 with the reducer to rotate the drive shaft.

[0025] The rotation sensor 281 is provided so as to be able to detect the rotation angle of the drive mechanism 40. The rotation angle of the drive mechanism 40 is the angle between the lower leg frame 24 and the foot frame 25, and corresponds to the angle of the ankle joint of the target leg of the user. However, there is no limitation on the angle detection principle of the rotation sensor 281. For example, the rotation sensor 281 is realized by a potentiometer, a rotary encoder, or the like, and detects the rotation angle of the drive shaft of the drive mechanism 40 or another member that rotates together with the drive shaft. The rotation sensor 281 is connected so as to be able to transmit a detection signal wirelessly or via a wire to the control device 10 (the input / output I / F 13). In this embodiment, the detection signal is transmitted to the control device 10 via a wire.

[0026] FIG. 3 is a schematic diagram for explaining the rotation angle of the drive mechanism 40 in this embodiment. The rotation sensor 281 in this embodiment detects the amount of displacement of the intersection angle between an extension line L1 indicating the extension direction of the lower leg frame 24 and an extension line L2 indicating the extension direction of the foot frame 25, as shown in FIG. As a result, based on the detection information from the rotation sensor 281, the rotation angle (ankle joint angle) of the drive mechanism 40 when the user is in an upright position is set to 0 degrees (reference angle), and when the ankle joint rotates in the dorsiflexion direction from that state, the rotation angle is detected as +θ (degrees), and conversely, when the ankle joint rotates in the plantar flexion direction, the rotation angle is detected as -θ (degrees). Note that when the user is in an upright position, it is assumed that the vertical direction (the direction in which the leg extends) and the sole of the foot are approximately at right angles.

[0027] [Control device for walking assistance device] The control device 10 includes a CPU 11, a memory 12, an input / output interface (I / F) 13, a communication unit 15, and the like. The control device 10 may be realized by a single-chip IC, or may be realized by multiple IC chips. The configuration of the control device 10 shown in FIG. 2 is merely an example, and the control device 10 may include components that are not shown. Furthermore, the number of each component shown in the figure is not limited to the example of FIG. 2.

[0028] The CPU 11 is a so-called processor, and may be one or more general central processing units (CPUs) or micro processing units (MPUs), or may alternatively or in addition to these be application specific integrated circuits (ASICs), digital signal processors (DSPs), graphics processing units (GPUs), field programmable gate arrays (FPGAs), etc. The memory 12 is a RAM (Random Access Memory), a ROM (Read Only Memory), etc. A control program (computer program) for implementing various functions of the present device 1 is stored in the memory 12. This control program may be stored in advance in the memory 12 such as a ROM, or may be installed from a portable recording medium such as a CD (Compact Disc) or a memory card, or from another computer on a network via the input / output I / F 13 or the communication unit 15, and then stored in the memory 12.

[0029] The input / output I / F 13 is an interface for inputting or outputting signals between externally connected components. In this embodiment, the toe pressure sensor 226, the heel pressure sensor 227, and the rotation sensor 281 are each connected to the input / output I / F 13, and the motor 30 is also connected to the input / output I / F 13. As a result, detection signals from the toe pressure sensor 226, the heel pressure sensor 227, and the rotation sensor 281 are input to the control device 10 via the input / output I / F 13, and a control signal is transmitted to the motor 30 via the input / output I / F 13. The communication unit 15 communicates with a user interface (UI) device (not shown). The communication unit 15 may support only wireless communication, may support only wired communication, or may support both. For example, the communication unit 15 performs wireless communication with the UI device. There is no limitation on the communication standard of wired communication or wireless communication supported by the communication unit 15.

[0030] The user interface (UI) device exchanges information with the control device 10 to provide a user interface for an operator such as a physical therapist. However, the user of the UI device is not limited in any way and may be the user himself who wears the device 1. The UI device is a general computer (which may be portable or stationary) equipped with a display unit and an input unit that accepts user input, and is equipped with, for example, a touch panel in which the display unit and the input unit are integrated. Although details will be described later, the UI device allows the user to display setting information indicating a time-series rotation pattern of the drive mechanism 40 and heel-off reference information in a configurable manner.

[0031] Before describing in detail the processing (operations) executed by the control device 10, an overview of its features will be given. The control device 10 includes an acquisition means for acquiring current phase information capable of identifying the current phase of the user's target leg during one walking cycle, and a control processing means for controlling the driving of the drive mechanism 40 by the motor 30 based on the current phase information. Here, the term "gait cycle" refers to the time from when one of the user's legs (target leg) touches the ground (start point) to when the target leg touches the ground again (end point), and can be expressed as 100% for example. This definition of the "gait cycle" is a standard one used in gait analysis and gait research, but this embodiment is not limited to this definition, and the start point of the gait cycle is not limited to heel contact. Furthermore, the "phase" of a gait cycle refers to a certain aspect within the gait cycle, and can be expressed as a percentage (between 0% and 100%) of 100% gait cycle, such as 35% or 60%.

[0032] The "current phase information" acquired by the acquisition means may be any information as long as it is capable of identifying the current phase of the user's target leg during one gait cycle. For example, the current phase information indicates the ratio (including percentage notation) of the current phase to the stepping cycle. In this case, the acquisition means may acquire the ratio from the elapsed time from a certain reference phase in the stepping cycle (for example, the start point or a foot flat reference point described later) to the current phase and the time length of the stepping cycle that is set separately, or may acquire the ratio from the ground contact state (heel contact state, heel off state, toe contact state, and toe off state) of the target leg of the user detected by the detection means (the toe pressure sensor 226 and the heel pressure sensor 227 in this embodiment). The acquisition means may also acquire the ratio based on information detected by other detection means such as an acceleration sensor. Furthermore, the acquisition means may acquire the ratio based on the myoelectric potential detected by the myoelectric potential sensor.

[0033] The current phase information may indicate the time elapsed from a certain reference phase in a gait cycle (for example, the start point or a foot flat reference point described later) to the current phase, or may indicate the ground contact state (heel contact state, heel off state, toe contact state, and toe off state) of the target leg of the user detected by the detection means (the toe pressure sensor 226 and the heel pressure sensor 227 in this embodiment), or may be formed by a combination of these. The current phase information may also include detection information detected by other detection means (such as an electromyogram sensor). Therefore, the phase that can be identified from the current phase information may be a phase estimated from the average leg movement for the user in a stride cycle, and some deviation from the phase corresponding to the actual walking movement of the target leg is acceptable.

[0034] Here, the acquisition means "acquires current phase information" means that the control device 10 is able to identify the current phase during one walking cycle of the user's target leg, and includes a broader meaning than is limited to acquiring current phase information from the outside via communication or the like, or generating new current phase information. In this embodiment, an example is shown in which the current phase is identified based on the time length of a stride cycle and the elapsed time from a reference phase, which are set separately as described below, while also identifying the current phase from the grounding state of the target leg detected by the toe pressure sensor 226 and heel pressure sensor 227. If only the elapsed time from the reference phase is used to identify the current phase, the toe pressure sensor 226 and heel pressure sensor 227 are not necessary. If other detection information (such as myoelectric potential information) is used to identify the current phase, other detection means (such as myoelectric potential sensor) capable of detecting that detection information is provided.

[0035] The control processing means is capable of executing plantar flexion control for rotating the drive mechanism 40 in a plantar flexion direction (-θ) and dorsiflexion control for rotating the drive mechanism 40 in a dorsiflexion direction (+θ) based on the current phase information, and executes free control for placing the drive mechanism 40 in a free state in either or both of a first section which is at least a part of the period during which the current phase information indicates a phase corresponding to a sole-contact state during a stride cycle, or a second section which is at least a part of the period during which the current phase information indicates a phase corresponding to a swing leg state during a stride cycle. Here, "during a gait cycle showing a phase corresponding to the sole of the foot touching the ground" refers to the section during the gait cycle in which both the toe and heel are on the ground, and "during a gait cycle showing a phase corresponding to the swing leg state" refers to the section during the gait cycle in which both the toe and heel are off the ground. Moreover, the term "section" refers to a period from one phase to another during a walking cycle.

[0036] The free state of the drive mechanism 40 refers to a state of the drive mechanism 40 in which no load is applied to the rotational movement of the ankle joint by the user wearing the leg attachment part 2. However, the free state of the drive mechanism 40 may include not only a state in which no load is applied (zero) but also a state in which a small load is applied due to the structure of the drive mechanism 40 and the motor 30. For this reason, the free state of the drive mechanism 40 can also be expressed as a state of the drive mechanism 40 in which the user can freely rotate the ankle joint.

[0037] By repeatedly conducting tests using the present device 1, the inventors have newly discovered that, rather than constantly assisting the rotational movement of the user's ankle joint with the drive mechanism 40, by leaving the drive mechanism 40 in a free state in either or both of the first and second sections described above and leaving it to the user's own strength, it is possible to reduce the discomfort felt by the user due to excessive assistance, suppress unnecessary movements, and achieve efficient and stable walking. As a result, by using this device 1, it is possible to reduce the discomfort that the user feels due to excessive assistance and to achieve efficient and stable walking, thereby promoting walking rehabilitation and making it easier to continue exercise therapy.

[0038] In addition, the inventors have found that this new knowledge is also effective for users suffering from knee osteoarthritis (hereinafter, sometimes referred to as knee OA). That is, it was found that a user suffering from knee OA can walk using the device 1 without pain or discomfort by free control in either or both of the first section and the second section. Therefore, by having users with knee OA use this device 1, they can carry out walking rehabilitation without any strain, and ultimately, they can achieve efficient, stable walking that reduces stress on the knees by suppressing unnecessary movements, thereby improving their knee OA. A person skilled in the art can easily imagine that the effects obtained by using this device 1 can be enjoyed not only by users suffering from knee OA, but also by users with severe illnesses such as paralysis due to stroke, and users with moderate or mild illnesses such as pain due to sprains.

[0039] The processing (operations) executed by the control device 10 will be described in detail below. FIG. 4 is a diagram conceptually showing the software configuration of the control device 10. As shown in FIG. The control device 10 realizes a software configuration as shown in Fig. 4 by causing the CPU 11 to execute a control program stored in the memory 12. Specifically, the control device 10 has, as the software configuration, an acquisition unit 101, a storage unit 102, a control processing unit 103, a UI processing unit 104, etc. However, since each software component shown in FIG. 4 is shown conceptually separated for ease of explanation, the software configuration realized by the control device 10 does not have to be clearly divided into each component as shown in FIG. 4.

[0040] The acquisition unit 101 identifies the current phase from the relationship between the time length of the stride cycle set in the gait cycle adjustment menu described later and the elapsed time from the start point of the stride cycle. In this embodiment, the acquisition unit 101 acquires the elapsed time as the current phase information. However, the acquisition unit 101 may identify the current phase using the elapsed time from a reference phase such as a foot flat reference point or a heel off reference point described later, or a set point described later, in addition to the start point.

[0041] The acquisition unit 101 in this embodiment may further acquire detection information from the toe pressure sensor 226 and the heel pressure sensor 227, and use this detection information to identify the current phase. The detection information from the toe pressure sensor 226 indicates whether the toe of the target leg of the user is in a grounded state (toe on ground state) or a ground-off state (toe off ground state). The detection information from the heel pressure sensor 227 indicates whether the heel of the target leg of the user is in a grounded state (heel on ground state) or a ground-off state (heel off ground state). For example, when the detection information indicates a change from the above-mentioned swing leg state to the heel contact state, the acquisition unit 101 identifies the current phase as 0% (start point PS), and thereafter identifies the current phase based on the elapsed time from this start point PS. The acquisition unit 101 may include the detection information in the current phase information. The acquisition unit 101 corresponds to an example of the acquisition means described in the overview.

[0042] In this embodiment, the acquisition unit 101 further acquires detection information from the rotation sensor 281. As described with reference to Fig. 3, the acquisition unit 101 can detect the rotation angle (ankle joint angle) of the drive mechanism 40 based on this detection information. The rotation angle of the drive mechanism 40 detected by the acquisition unit 101 is detected as +θ (degrees) when rotated in the dorsiflexion direction with 0 degree as a reference angle, and as -θ (degrees) when rotated in the plantar flexion direction.

[0043] The storage unit 102 stores setting information indicating a time-series rotation pattern of the drive mechanism 40 for one walking cycle of the target leg of the user. This setting information includes, for each of a plurality of set points having mutually different phases during a walking cycle, correspondence information between the phase during the walking cycle and the target rotation angle of the drive mechanism 40 at that phase. In the setting information in this embodiment, the phases and target rotation angles of four set points (set points P1, P2, P3, and P4 described below) are indicated. In addition to these set points, the time-series rotation pattern also includes a start point PS (phase 0%, target rotation angle 0 degrees) and an end point PE (phase 100%, target rotation angle 0 degrees) at which the phase and target rotation angle are fixed. This setting information is referenced by the control processing unit 103 described later and is used for driving control of the driving mechanism 40.

[0044] In this embodiment, the holding unit 102 can hold standard setting information indicating a standard time-series rotation pattern of the drive mechanism 40 and customized setting information indicating a time-series rotation pattern customized for a user. The standard setting information is held in the holding unit 102 (memory 12) in an unchangeable state, and the customized setting information is held in the holding unit 102 in an changeable state. The storage unit 102 can store a plurality of standard setting information and a plurality of customized setting information each having a different time-series rotation pattern. However, the storage unit 102 may store only one or more standard setting information and may not store customized setting information. Details of such standard setting information and customized setting information will be described later.

[0045] In this embodiment, the storage unit 102 further stores heel-off reference information indicating the phase of the heel-off reference point in one walking cycle of the target leg of the user. The heel-off reference point corresponds to the reference phase in the stride cycle when the heel should turn from the sole contact state to the heel-off state, and can be considered as the timing when the foot starts to kick off the ground to transition from the stance phase to the swing phase. However, the heel-off reference point here is merely a reference point, and does not indicate the timing when the heel actually leaves the ground during walking (hereinafter, sometimes referred to as the actual heel-off point). Therefore, the timing of the heel-off reference point may or may not match the timing of the actual heel-off point. This heel-off reference information is also referred to by the control processing unit 103, which will be described later, and is used for driving control of the driving mechanism 40.

[0046] The UI processing unit 104 displays the standard setting information and customized setting information stored in the storage unit 102 on the UI device, and allows the user to select one piece of setting information from the standard setting information and customized setting information to be used for control by the control processing unit 103. The UI processing unit 104 identifies setting information selected by a user operation on the UI device, and notifies the control processing unit 103 of the selection information. Furthermore, when the standard time series rotation pattern of the standard setting information displayed on the UI device is changed by a user operation, the UI processing unit 104 causes the storage unit 102 to store the changed time series rotation pattern as new customized setting information. When the time series rotation pattern of the customized setting information displayed on the UI device is changed by a user operation, the UI processing unit 104 reflects the change in the customized setting information stored in the storage unit 102.

[0047] Furthermore, the UI processing unit 104 can also display the heel-off criterion information on the UI device in a changeable manner. When the heel-off criterion information displayed on the UI device is changed by a user operation, the UI processing unit 104 instructs the storage unit 102 to reflect the change in the heel-off criterion information stored in the storage unit 102. A method for changing the heel-off criterion information will be described later. From the above, the UI processing unit 104 corresponds to a transmitting means for transmitting the heel-off reference information held in the holding unit 102 to a display device (UI device) in order to display information relating to the heel-off reference point on the display device, and corresponds to an updating means for updating the heel-off reference information held in the holding unit 102 to indicate the phase of the heel-off reference point after the change when a user operation is performed on the display device to change the phase of the heel-off reference point. By making the phase of the heel-off reference point changeable in this manner, the drive control at the phase of the heel-off reference point by the control processing unit 103, which will be described later, can be adapted for each user, thereby making it possible to provide walking movement assistance that is tailored to the user.

[0048] FIG. 5 is a diagram showing an example of a walking assistance setting screen displayed on the UI device. The UI device displays a walking motion setting screen (hereinafter sometimes abbreviated as a setting screen) as shown in FIG. 5 based on the standard setting information, customized setting information, and heel-off reference information transmitted from the UI processing unit 104. On the setting screen, a rotation pattern graph is displayed in the main area GM, and adjustment menus such as a rotation pattern selection menu, a walking cycle adjustment menu, an angle amplification rate adjustment menu, and a sensor sensitivity adjustment menu are displayed in the menu area GS.

[0049] The rotation pattern graph displays the setting information selected from the standard setting information and the customized setting information in the form of a line graph in which the horizontal axis indicates the phase of the gait cycle and the vertical axis indicates the target rotation angle of the drive mechanism 40. The target rotation angle of the drive mechanism 40 on the vertical axis can also be said to indicate the target ankle joint angle. The drive control of the drive mechanism 40 is performed based on the time-series rotation pattern displayed by this rotation pattern graph.

[0050] In the example of Fig. 5, the start point PS and end point PE of a step cycle and four set points P1, P2, P3, and P4 are plotted as black square points, and each point is connected by a straight line. In this embodiment, as shown in Fig. 5, the start point PS is the time when the heel of the target leg (the leg to which the leg attachment unit 2 is attached) touches the ground and the toe is off the ground, and the end point PE is the time when the same target leg next steps out and the heel touches the ground and the toe is off the ground. The four set points are set as follows: set point P1 indicates a target rotation angle of +10 degrees (dorsiflexion side) at a phase of 15%, set point P2 indicates a target rotation angle of +10 degrees (dorsiflexion side) at a phase of 50%, set point P3 indicates a target rotation angle of -15 degrees (plantar flexion side) at a phase of 60%, and set point P4 indicates a target rotation angle of 0 degrees at a phase of 70%.

[0051] In such a rotation pattern graph, the phases and target rotation angles of the set points P1, P2, P3, and P4 are changeable. The user can change the phases and target rotation angles of each set point by operating the UI device to move the positions of the set points P1, P2, P3, and P4 in the rotation pattern graph in the horizontal and vertical directions. By such operations, customization setting information can be generated or updated.

[0052] In addition, the vertical line PH corresponding to the heel-off reference information is drawn on the rotation pattern graph. That is, the vertical line PH indicates the phase of the heel-off reference point. In the example of Fig. 5, the heel-off reference point is set to a phase of 55%. In addition, the phase of the heel-off reference point can be changed in the rotation pattern graph. In the example of Fig. 5, a slider HS is displayed below the rotation pattern graph, and the displacement of this slider HS is linked to the displacement of the vertical line PH. This allows the user to change the phase of the heel-off reference point by moving the slider HS horizontally by operating the UI device, thereby changing the heel-off reference information. In addition, in the example of Fig. 5, the lateral slide of the slider HS is limited to the range of 50% to 70%. By limiting the adjustment range of the heel-off reference point phase in this way, it is possible to eliminate erroneous setting of the heel-off reference point phase.

[0053] The rotation pattern selection menu allows the user to select a time-series rotation pattern to be executed from the standard setting information and the customized setting information. In the example of Fig. 5, the time-series rotation pattern "A" is selected. As described above, the drive control of the drive mechanism 40 is executed according to the time-series rotation pattern selected in the rotation pattern selection menu.

[0054] The walking cycle adjustment menu allows the user to adjust the walking cycle, which differs from person to person, to a walking cycle that suits the current user. The walking cycle may be adjusted by the user's operation of the left and right buttons (UP button and DOWN button) displayed in the menu area GS in Fig. 5, or may be measured automatically. The walking cycle can be measured by various known methods. In Fig. 5, the time length of a stepping cycle is set to 1080 ms as displayed in the menu area GS. The current phase in a stepping cycle is identified based on the relationship between the time elapsed from the start point PS and the time length of a stepping cycle set in the gait cycle adjustment menu. In the example of Fig. 5, the timing when the time elapsed from the start point PS is 108 ms is identified as the 10% phase in a stepping cycle, and the timing when the time elapsed from the start point PS is 540 ms is identified as the 50% phase.

[0055] The angle amplification rate adjustment menu allows the setting points P1, P2, P3, and P4 of the rotation pattern graph to be increased or decreased at a fixed rate. The sensor sensitivity adjustment menu makes it possible to adjust the detection sensitivity of the toe pressure sensor 226 and the heel pressure sensor 227. For example, the sensor sensitivity adjustment menu makes it possible to adjust the sensor sensitivity at that time to an arbitrary sensitivity (0% is the reference load) based on the detected pressure when the user takes a standing posture (standing position) while wearing the leg attachment unit 2.

[0056] The control processing unit 103 controls the driving of the drive mechanism 40 by the motor. In this embodiment, the control processing unit 103 controls the rotation speed, rotation direction, etc. of the motor 30 to control the rotation operation of the drive mechanism 40. The control processing unit 103 corresponds to an example of the control processing means described in the overview. That is, the control processing unit 103 can execute plantar flexion control for rotating the drive mechanism 40 in a plantar flexion direction (-θ) and dorsiflexion control for rotating the drive mechanism 40 in a dorsiflexion direction (+θ) based on the current phase information from the acquisition unit 101, and executes free control for making the drive mechanism 40 free in one or both of a first section which is at least a part of the period during which the current phase information indicates a phase corresponding to a sole contact state during a stepping cycle, and a second section which is at least a part of the period during which the current phase information indicates a phase corresponding to a swing leg state during a stepping cycle. In the example of FIG. 5, the free control is executed in both the first section and the second section.

[0057] The free state of the drive mechanism 40 can be realized by placing the motor 30 in an unloaded state, by releasing a part of the link that transmits power from the motor 30, or the like. The unloaded state of the motor 30 can be said to be a state in which the power supplied to the motor 30 is cut off, or a state in which the output shaft of the motor 30 can be manually rotated from a stopped state. However, the method for realizing the free control by the control processing unit 103 is not limited.

[0058] When performing plantar flexion control, dorsiflexion control, free control, etc., the control processing unit 103 uses current phase information obtained from the acquisition unit 101 and setting information selected from standard setting information and customized setting information stored in the storage unit 102. Specifically, the control processing unit 103 executes dorsiflexion control or plantar flexion control so as to achieve the target rotation angle of each set point at a timing corresponding to the phase of each set point, based on the correspondence relationship between the phase of each set point indicated in the selected setting information and the target rotation angle of the drive mechanism 40. In addition, when the target rotation angles of a first and second setting point, which are adjacent in phase among the multiple setting points in the setting information, are identical, the control processing unit 103 executes free control between the timing corresponding to the phase of the first setting point and the timing corresponding to the phase of the second setting point. In this manner, in this embodiment, by setting the same target rotation angle between set points whose phases are adjacent in the setting information, it is possible to cause the control processing unit 103 to execute free control between those set points.

[0059] Fig. 6(a) is a diagram showing an example of standard setting information showing a standard time-series rotation pattern of the drive mechanism 40, and Fig. 6(b) is a diagram showing an example of customized setting information showing a customized time-series rotation pattern. In Figs. 6(a) and (b), each time-series rotation pattern is shown in the display format of a rotation pattern graph. The customized setting information in Fig. 6(b) is generated by customizing the standard setting information in Fig. 6(a) according to the user. The time series rotation patterns illustrated in Figures 6(a) and 6(b) are, as described above as an overview of the characteristics, newly discovered by the inventors, and enable improved walking stability and reduced discomfort to the user. When the current phase information indicates the phase of the start point PS (0%), i.e., when the detection information indicates a change from the swing leg state to the heel-contact state, the control processing unit 103 sets the rotation angle of the drive mechanism 40 at that time to the rotation angle of the start point PS of one walking cycle (0 degrees), and thereafter performs drive control as follows based on the rotation pattern indicated by the selected setting information. Note that the rotation angle of the start point PS (0 degrees) may be set as an absolute angle so that the user can walk easily.

[0060] Between the start point PS and the set point P1, that is, between the phases 0% and 15%, dorsiflexion control is executed so that the target rotation angle changes from 0 degrees to +10 degrees. Then, since the target rotation angles of the set points P1 and P2, which have adjacent phases, are the same at +10 degrees, free control is executed between the phases 15% and 50%. Then, between the set points P2 and P3, that is, between the phases 50% and 60%, plantar flexion control is executed so that the target rotation angle changes from +10 degrees to -15 degrees. Then, between the set points P3 and P4, that is, between the phases 60% and 70%, dorsiflexion control is executed so that the target rotation angle changes from -15 degrees to 0 degrees. Then, since the target rotation angles of the set point P4 and the end point PE, which have adjacent phases, are the same at 0 degrees, free control is executed between the phases 70% and 100%.

[0061] Thus, it can be said that the control processing unit 103 executes the above-mentioned free control of the first section following the dorsiflexion control, executes the above-mentioned plantarflexion control and dorsiflexion control in sequence following the above-mentioned free control of the first section, and executes the above-mentioned free control of the second section following the dorsiflexion control, in one walking cycle of the target leg. Furthermore, the control processing unit 103 can also be said to continue the free control of the second section while the current phase information obtained from the acquisition unit 101 indicates a phase corresponding to the free leg state in a step cycle (from the set point P4 to the set point PE). In addition, the control processing unit 103 can also be said to control the rotation angle of the drive mechanism 40 to be larger on the dorsiflexion side at the start of the free control of the first section (the target rotation angle is set to +10 degrees) than at the start of the free control of the second section (the target rotation angle is set to 0 degrees). By storing standard setting information indicating such a time-series rotation pattern in the holding unit 102 and using it to control the drive of the drive mechanism 40, it is possible to improve the stability of walking and reduce the discomfort the user feels when walking, thereby facilitating walking rehabilitation and making it easier to continue exercise therapy.

[0062] In addition, by setting the target rotation angles of adjacent set points in the rotation pattern graph display on the walking assistance setting screen to be the same, such as set points P1 and P2, and set point P4 and end point PE in Figure 6, free control can be executed between them. In addition, there may be cases where it is desired to fix a certain target rotation angle in a certain section within a walking cycle. To deal with this case, by selecting a line segment (between P1 and P2, between P4 and PE in the example of FIG. 5) connecting adjacent set points with the same target rotation angle in the rotation pattern graph, it may be possible to set whether to execute free control or fixed control (control to fix the target rotation angle) in that section. In this case, the setting information may further set not only the correspondence information between the phase and the target rotation angle, but also information indicating whether free control or fixed control is to be executed as the control to be executed between adjacent set points with the same target rotation angle. Furthermore, it may be possible to execute both free control and fixed control in that section (between adjacent set points with the same target rotation angle).

[0063] Furthermore, the control processing unit 103 performs the following drive control based on the current phase information and detection information obtained from the acquisition unit 101 and the heel-off reference information held by the holding unit 102. When the detection information indicates a heel-contact state at a timing corresponding to the phase of the heel-off reference point that can be specified by the current phase information (the elapsed time from the reference point), the control processing unit 103 starts fixed control for fixing the rotation angle of the drive mechanism 40 or free control, and then transitions to dorsiflexion control or plantar flexion control when the detection information indicates a change from the heel-contact state to the heel-off state. In this case, in the fixed control, the rotation angle may be fixed at the time (at the timing corresponding to the phase of the heel-off reference point), or may be fixed at a predetermined target rotation angle (for example, 0 degrees).

[0064] When the detection information indicates a heel-on-ground state at a timing corresponding to the phase of the heel-off reference point that can be specified by the current phase information (the elapsed time from the reference point), it indicates that the heel is still on the ground when the heel should be lifted off the ground as the foot kicks the ground to transition from the stance phase to the swing phase. The inventors have found that in such a state where gait disturbance occurs, the walking can be stabilized by fixing the rotation angle of the drive mechanism 40 or by setting the drive mechanism 40 in a free state so as not to provide excessive assistance, and then connecting it to plantar flexion control that promotes heel-off, which can stabilize the walking and reduce the discomfort.

[0065] As described above, the actual heel-off point indicates the timing when the heel actually leaves the ground after starting to kick the ground in order to transition from the stance phase to the swing phase. However, the inventors have discovered that there are users who would benefit from further assistance in kicking the ground at the actual heel-off point (hereinafter referred to as users requiring assistance) and users who do not require assistance (hereinafter referred to as self-help users). Therefore, for example, it is preferable to set the phase of the heel-off reference point for a user who needs assistance to a phase as exemplified in Fig. 6(a), and for a user who needs assistance to a phase as exemplified in Fig. 6(b). That is, it is preferable that the heel-off reference information for a user who needs assistance is set so that the phase of the heel-off reference point is located in the middle of the execution of plantar flexion control. In the example of Fig. 6(b), the heel-off reference point is set as a switching point from plantar flexion control to dorsiflexion control. Therefore, in this case, the control processor 103 transitions to dorsiflexion control when the detection information indicates a change from a heel-on-ground state to a heel-off state.

[0066] In the preferred time series rotation pattern illustrated in FIGS. 6(a) and (b), a set point P1 adjacent to the starting point PS is set at the foot flat reference point (the point where the entire plantar surface of the foot will be in contact with the ground). The foot flat reference point corresponds to the reference phase in the stride cycle when the toe should change from lift-off to contact after the heel touches the ground (from the starting point), and may or may not coincide with the actual timing during walking (hereinafter sometimes referred to as the actual foot flat point). When the set point P1 is set to correspond to the foot flat reference point, the control processing unit 103 performs the following drive control at a timing corresponding to the phase of the set point P1 that can be specified by the current phase information (the time elapsed from the start point PS) obtained from the acquisition unit 101. The control processing unit 103 starts dorsiflexion control from the start point PS, executes dorsiflexion control so as to achieve the target rotation angle of the set point P1 at a timing corresponding to the phase of the set point P1 that can be specified by the current phase information (the time elapsed from the start point PS), and starts fixed control or free control to fix the rotation angle of the drive mechanism 40 if the detection information acquired by the acquisition unit 101 at the timing corresponding to the phase of the set point P1 does not indicate a toe-on-ground state. In this case, in the fixed control, the rotation angle may be fixed at the time (at the timing corresponding to the phase of the set point P1), or may be fixed at a predetermined target rotation angle (for example, 0 degrees) that is determined in advance.

[0067] If the detection information does not indicate a toe-on-ground state at a timing corresponding to the phase of the foot-flat reference point specified by the duration from the start point PS, this indicates that the toes have not yet actually touched the ground at the timing that should be the actual foot-flat point. The inventors have found that in such a state where gait disturbance occurs, the walking can be stabilized and the discomfort in walking can be reduced by fixing the rotation angle of the drive mechanism 40 or by setting the drive mechanism 40 in a free state and not providing excessive assistance. Moreover, such a deviation in relation to the foot flat reference point (set point P1) is a deviation between the phase (current phase) of the foot flat reference point specified by the elapsed time from the start point and the actual foot flat point (actual current phase) of the actual walking motion. If the time-series rotation pattern set in the setting information is followed in a state in which this deviation exists, the free control may end earlier than the desired timing in the actual walking motion.

[0068] Therefore, in this embodiment, when the detection information acquired by the acquisition unit 101 at the timing corresponding to the phase of the foot flat reference point (set point P1) specified by the current phase information (duration from the start point) does not indicate a toe-on-ground state, the control processing unit 103 continuously executes free control for a predetermined time length from the timing when the detection information indicates a toe-on-ground state. The predetermined time length here is the time length between the phase of the set point P1 and the phase of the set point P2 set in the setting information, and this time length can be obtained from the time length of the step cycle set in the walking cycle adjustment menu. This allows the free control in the first section to be executed for an appropriate length of time in accordance with the user's actual walking motion, so that the above-mentioned effects associated with the execution of the free control can be reliably obtained. In addition, if fixed control is started when the detection information does not indicate a toe-on-ground state at the timing corresponding to the phase of the foot flat reference point (set point P1) specified by the current phase information (duration from the starting point), the control processing unit 103 starts free control as soon as the detection information indicates a toe-on-ground state, and continues the free control for the specified length of time.

[0069] [Walking movement assistance method] FIG. 7 is a flowchart showing an example of the operation of the walking movement assist device 1 according to this embodiment. Hereinafter, the walking motion assist method according to this embodiment will be described with reference to Fig. 7. Each step shown in Fig. 7 is executed by the control processing unit 103, and it is assumed that the process starts from a state in which standard setting information or customized setting information showing a preferred time-series rotation pattern as shown in Fig. 6(a) and Fig. 6(b) is selected in a rotation pattern selection menu. Although not shown in Fig. 7, the acquisition unit 101 successively acquires detection information, and the control processing unit 103 can refer to the detection information acquired by the acquisition unit 101. 7 are similar to the processing contents of the control processing unit 103 described above, the details of each step will be omitted below as appropriate.

[0070] When the current phase information obtained from the acquisition unit 101 indicates the phase (0%) of the start point PS, the control processing unit 103 sets the rotation angle of the start point PS to 0 degrees and starts dorsiflexion control (S71). At this time, the control processing unit 103 executes dorsiflexion control at an angular velocity that achieves the target rotation angle (+10 degrees) of the set point P1 at the timing corresponding to the phase (15%) of the set point P1. The acquisition unit 101 measures the elapsed time from the start point PS and acquires it as the current phase information.

[0071] The control processing unit 103 determines whether the current phase is the phase of the set point P1 based on the current phase information obtained from the acquisition unit 101 (S72). The control processing unit 103 continues to execute the dorsiflexion control until the current phase becomes the phase of the set point P1 (S72; NO). The set point P1 corresponds to the foot flat reference point as described above. When the current phase becomes the phase of the set point P1 (S72; YES), the control processing unit 103 judges whether or not the detection information acquired by the acquisition unit 101 indicates a sole-on-ground state (heel-on-ground state and toe-on-ground state) (S73). When the detection information does not indicate a toe-on-ground state (S73; NO), the control processing unit 103 executes free control (S75) if free control is not in progress (S74; NO). At this time, if lock control is not in progress (S74; NO), lock control may be executed (S75).

[0072] When the detection information indicates a toe-on-ground state (S73; YES), the control processing unit 103 instructs the acquisition unit 101 to correct the current phase to the phase of set point P1 (S76). As a result, when the set point P1 (foot-flat reference point) does not match the actual foot-flat point, the interval from the set point P1 to the set point P2 is adjusted to the timing of the actual foot-flat point. For this reason, the step (S76) may be a step of resetting a timer that measures the time from the set point P1 to the set point P2. Next, if the free control is not in progress (S77; NO), the control processing unit 103 executes the free control (S78). If the lock control is executed in step (S75), the determination in step (S77) is not necessary, and the free control may be executed in step (S78). In this manner, in this embodiment, when the set point P1 does not match the actual foot flat point, free control is started from the timing corresponding to the phase of the set point P1, or, after lock control is executed from the timing corresponding to the phase of the set point P1 to the timing of the actual foot flat point, free control is executed from the timing of the actual foot flat point. This makes it possible to provide walking assistance that stabilizes walking and reduces discomfort even when gait is disturbed.

[0073] Next, the control processing unit 103 continues to execute the free control until the current phase becomes the phase of the set point P2 (S79; NO). In the example of FIG. 7, the current phase is corrected to the phase of the set point P in the step (S76), but the step (S76) may be deleted and a new step may be provided between the steps (S79) and (S80) to correct the current phase to the phase of the set point P2. In this case, when the control processing unit 103 judges NO in the step (S73) even once and then judges YES in the step (S73), the control processing unit 103 may continuously execute the free control for a predetermined time length from the timing when the detection information indicates the toe-ground state. The predetermined time length at this time is set to the time length between the phase of the set point P1 and the phase of the set point P2 set in the setting information. Therefore, in this case, in step (S79), it is determined whether the elapsed time since the start of free control reaches the predetermined time length, and when the elapsed time reaches the predetermined time length, the above-mentioned new step (correction of the current phase) is executed, and then step (S80) is executed.

[0074] In the example of Fig. 7, when the current phase becomes the phase of the set point P2 (S79; YES), the control processing unit 103 starts the plantar flexion control (S80). At this time, the control processing unit 103 executes the plantar flexion control at an angular velocity that makes the target rotation angle of the set point P3 (-15 degrees) at the timing corresponding to the phase of the set point P3 (60% in Fig. 6(a)) from the set point P2 (phase 50%, target rotation angle 10 degrees).

[0075] Next, the control processor 103 continues to execute the plantar flexion control until the current phase specified by the current phase information becomes the phase of the heel-off reference point indicated by the heel-off reference information (55% in FIG. 6(a)) (S81; NO), and when the current phase becomes the phase of the heel-off reference point (S81; YES), it judges whether the detection information indicates a toe-on-ground state and a heel-off state (S82). If the detection information does not indicate a heel-off state (S82; NO), the control processor 103 executes the free control (S84) if the free control is not being performed (S83; NO). At this time, if the lock control is not being performed (S83; NO), the lock control may be executed (S84).

[0076] When the detection information indicates a heel-off state (S82; YES), the control processing unit 103 instructs the acquisition unit 101 to correct the current phase to the phase of the heel-off reference point (S85). The phase of the heel-off reference point can be acquired from the heel-off reference information. This makes it possible to correct the deviation of the current phase when the heel-off reference point does not match the actual heel-off point. Then, the control processing unit 103 determines whether or not the current phase specified by the current phase information is the phase of the set point P3 (S86). If the current phase is not the phase of the set point P3 (S86; NO), the control processing unit 103 executes the plantar flexion control again (S87). In this embodiment, when the heel-off reference point is set between the set points P2 and P3 as shown in FIG. 6(a), plantar flexion control is started at the phase of the set point P2, and when the heel-off reference point does not coincide with the actual heel-off point, the control is switched to free control or lock control from the phase of the heel-off reference point to the timing of the actual heel-off point, and then plantar flexion control is executed again from the timing of the actual heel-off point. As a result, even if an irregularity in gait occurs, forward propulsion can be generated by further kicking the ground after heel-off, stabilizing walking and assisting smooth forward movement while reducing discomfort.

[0077] In the example of Fig. 7, the current phase is corrected to the phase of the heel-off reference point P in step (S85), but step (S85) may be deleted. In this case, the current phase determined by the duration from the reference point is out of sync with the actual walking state, and plantar flexion control is executed earlier than the original timing.

[0078] When the current phase specified by the current phase information becomes the phase of the set point P3 (S85; YES), the control processing unit 103 starts the dorsiflexion control (S88). At this time, the control processing unit 103 executes the dorsiflexion control at an angular velocity that makes the target rotation angle of the set point P4 (0 degrees) at the timing corresponding to the phase of the set point P3 (phase 60% in FIG. 6(a), target rotation angle -15 degrees) of the set point P4 (70% in FIG. 6(a)). Here, in the case where the set point P3 is set to correspond to the heel-off reference point as shown in FIG. 6(b), when the detection information indicates a heel-off state (S82; YES), the current phase is the phase of the set point P3 (S86; YES), so that the dorsiflexion control is executed (S88) without re-executing the plantar flexion control (S87).

[0079] Next, the control processor 103 continues to execute the dorsiflexion control until the current phase becomes the phase of the set point P4 (S89; NO), and when the current phase becomes the phase of the set point P4 (S89; YES), starts the free control (S90). This free control continues to be executed until the end point PE of the walking cycle.

[0080] [Variations] The above is an example of the walking motion assist device 1 and the walking motion assist method according to the present embodiment. The walking motion assist device 1 is not limited to the above-mentioned configuration, and may be partially modified as appropriate as long as it has at least a part of the above-mentioned configuration. In addition, in Fig. 7, a plurality of steps (processing) are shown in sequence, but the content of each step of the walking motion assistance method according to the present embodiment and the order of execution of each step are not limited to the example in Fig. 7. The order of execution of each step may be changed within the scope of the spirit of the invention.

[0081] For example, in the above embodiment, the heel-off reference information indicates the phase of the heel-off reference point, and the phase of the heel-off reference point can be changed using the slider HS on the walking assistance setting screen (see Figure 5), but the heel-off reference point may be a setting point (heel-off reference setting point) that is treated in the same way as the setting points indicated in the standard setting information and customized setting information. Fig. 8(a) is a diagram showing a modified example of heel-off reference information. In Fig. 8(a), the heel-off reference set point is indicated by the symbol PH. In this case, the phase and the target rotation angle of the heel-off reference set point PH may be made variable, similar to the other set points P1, P2, P3, and P4.

[0082] FIG. 8B is a diagram showing a modified example of the standard setting information. In the above embodiment, an example was given in which the standard setting information and the customized setting information indicate the phases and target rotation angles of four set points, but it is also possible to modify the standard setting information and the customized setting information so as to indicate the phases and target rotation angles of five or more set points. In this case, the set points can be used to change the angular velocity in plantar flexion control or dorsiflexion control. In the modification of Fig. 8(b), in addition to the set points P1, P2, P3, and P4, a set point P23 is further provided, and the set point P23 between the set point P2 as the start point of the plantar flexion control and the set point P3 as the end point of the plantar flexion control is set to change the angular velocity of the plantar flexion control. Similarly, a new set point may be set between the set point P3 as the start point of the dorsiflexion control and the set point P4 as the end point of the dorsiflexion control to change the angular velocity of the dorsiflexion control. The number of set points may be appropriately changeable by a user operation on the walking assistance setting screen (see FIG. 5).

[0083] Furthermore, in the above embodiment, an example has been shown in which the target rotation angle of the end point PE is fixed at 0 degrees, but the target rotation angle of the end point PE may be made changeable. In this case, the UI processing unit 104 causes the UI device to display the target rotation angle of the end point PE of the rotation pattern graph in a changeable manner. Specifically, the UI processing unit 104 displays the position of the end point PE in a manner that allows it to be moved only vertically by a user operation on the rotation pattern graph. When the target rotation angle of the end point PE displayed on the UI device is changed by a user operation, the UI processing unit 104 instructs the storage unit 102 to reflect the change in the setting information stored by the storage unit 102. From the above, the UI processing unit 104 corresponds to a transmitting means for transmitting the setting information held in the holding unit 102 to a display device (UI device) in order to display information regarding the end point PE on the display device, and corresponds to an updating means for updating the setting information held in the holding unit 102 to indicate the changed target rotation angle of the end point PE when a user operation is performed on the display of the display device to change the target rotation angle of the end point PE. In this way, the free control of the second section can be started at a rotation angle toward the dorsiflexion side of 0 degrees, making it possible to stabilize movement during the swing phase even for users who are finding it difficult to control ankle joint movement. When the end point PE is reached (when the start point PS of the next walking cycle is reached), the current phase is immediately returned to the phase of the start point PS (0%). If the current rotation angle of the drive mechanism 40 is not 0 degrees at this time, control may be performed to rotate the drive mechanism 40 to a reference angle (0 degrees) with the target rotation angle set to 0 degrees, or such control may be omitted and only the current phase may be returned.

[0084] Although not specifically mentioned in the above embodiment, the control processing unit 103 may perform the following control for the deviation from the actual walking motion at the end point PE. Specifically, the control processing unit 103 may execute fixed control or free control when the detection information indicates a heel-off state at the timing corresponding to the phase of the end point PE specified by the current phase information (elapsed time from the reference point). As illustrated in Figures 5 and 6, when free control is set to be executed between the set point P4 and the end point PE, the execution of free control can be continued from the timing corresponding to the phase of the end point PE identified by the current phase information (elapsed time from the reference point) until the detection information indicates a heel contact state, or the free control can be switched to execute fixed control. In this way, even if gait disturbance occurs at the end point PE of the step cycle, excessive assistance is not provided by free control or fixed control until heel contact, thereby stabilizing walking and reducing the discomfort felt when walking.

[0085] In addition, in the above-described embodiment, an example was shown in which the time-series rotation pattern of the drive mechanism 40 and the rotation pattern graph displaying it in line graph format are shown as the progression of the target rotation angle within one walking cycle (correspondence information between phase and target rotation angle), but they may also be shown as the progression of angular velocity, angular acceleration or joint torque within one walking cycle, or as the progression of a combination of any two or more of the target rotation angle, angular velocity, angular acceleration or joint torque within one walking cycle.

[0086] In the above embodiment, the advantage of executing free control in either or both of the first and second sections has been shown, but for a user who has difficulty controlling ankle joint movement due to a stroke or the like, there may be cases where it is better to execute fixed control to fix the rotation angle of the drive mechanism 40 in either or both of the first and second sections. For example, when the rotation angle of the drive mechanism 40 is fixed at +10 degrees (dorsiflexion side) in the first section, the heel rocker function (movement of rolling the lower leg forward with the heel as an axis) can be promoted, and the hindrance of forward propulsion associated with early forefoot grounding due to weakening or paralysis of the tibialis anterior (dorsiflexor) can be avoided.

[0087] Furthermore, the control processing unit 103 can also cause the output means to issue a notification in a predetermined manner when the current phase indicated by the current phase information obtained from the acquisition unit 101 becomes the phase of each set point indicated by the selected setting information. Such notification processing may be executed for all set points indicated by the setting information, or for one or more of the set points, or for the set points indicated by the setting information as well as one or more of the start point PS, end point PE, foot flat reference point, and heel off reference point. This allows the user to take advantage of the notification to time their walking so that they can easily achieve smooth walking movements. Various notification modes, such as sound, light, vibration, etc., can be adopted, and the device 1 may be provided with an output means (speaker, light emitting unit, vibration unit, etc.) corresponding to the notification mode. For example, in the case of notification by sound such as a buzzer, feedback from hearing can be provided, which can improve the rehabilitation effect, such as enhancing the walking sensation. EXAMPLES

[0088] In this example, the effect of the walking motion assist device 1 in the above-mentioned embodiment was verified. At this time, in this device 1, the standard setting information shown in Fig. 6(a) was selected, and drive control was performed according to the time-series rotation pattern shown in the standard setting information. In this verification, the specific hip joint angle, knee angle, and ankle joint angle were measured when the same able-bodied individual walked normally without wearing anything (referred to as the first case) and when they walked five steps while wearing device 1, then removed device 1 and walked normally (referred to as the second case). The specific hip joint angle means the angle between the line passing through the greater trochanter and the metatarsal head and the perpendicular line passing through the greater trochanter in the sagittal plane. The specific hip joint angle, knee angle, and ankle joint angle were measured using a video analysis device. Specifically, markings were made on characteristic parts required to specify the angles to be measured, such as the greater trochanter and the lateral side of the knee, and the angles were measured based on the positional relationship of these markings.

[0089] FIG. 9 is a graph showing the transition of the specific hip joint angle, knee angle, and ankle joint angle during a step cycle in a first case where the same able-bodied person walked normally without wearing anything, and in a second case where the person walked five steps while wearing the device 1 and then removed the device 1 and walked normally. In FIG. 9, the first case is indicated as "pre" and the second case is indicated as "post." FIG. 9(a) shows the transition of the specific hip joint angle during a step cycle, FIG. 9(b) shows the transition of the knee angle during a step cycle, and FIG. 9(c) shows the transition of the ankle joint angle during a step cycle. In each graph in FIG. 9, the horizontal axis indicates the phase (0% to 100%) during the gait cycle. The vertical axis of the graph in FIG. 9(a) indicates the angle, with a negative value indicating when the toes are in the direction of travel from the perpendicular line passing through the greater trochanter, and a positive value indicating when the toes are in the direction opposite to the perpendicular line passing through the greater trochanter. The vertical axis of the graph in FIG. 9(b) indicates the angle, with a reference angle of 0 degrees, the angle in the flexion direction from the reference angle is indicated as a positive value, and the angle in the extension direction is indicated as a negative value. The vertical axis of the graph in FIG. 9(c) indicates the angle, with a reference angle of 0 degrees, the angle in the dorsiflexion direction from the reference angle is indicated as a positive value, and the angle in the plantar flexion direction is indicated as a negative value.

[0090] In Figure 9(a), the peak of the specific hip joint angle is about 5% ahead in the second case (post) compared to the first case (pre). This shows that the walking speed is improved in the second case compared to the first case, and that the push-off is functioning effectively. The peak of the specific hip joint angle corresponds to the timing when the front part of the foot leaves the floor after heel-off, so the advancement of the peak indicates an extension of the stance time, and it is believed that the weight can be firmly placed on the front of the foot. Therefore, it is believed that the push-off functions effectively, and the forward propulsion force is obtained, which contributes to the improvement of the walking speed. In Figure 9(b), the peak of knee angle extension in the late stance phase (30% to 50%) is located near 50% in the first case (pre), whereas in the second case (post) it is located near 35%, meaning that the timing of the peak knee extension in the stance phase is at a more appropriate position in the second case than in the first case. For this reason, it can be seen that the knee movement in the stance phase is more stable in the second case than in the first case. In Figure 9(c), the plantar flexion peak located between 60% and 70% is larger (the angle value is smaller) in the second case than in the first case. This shows that the second case allows a stronger push-off movement than the first case.

[0091] From the above, it was demonstrated that the walking assistance provided by wearing the device 1, which is driven and controlled by the time-series rotation pattern shown in Fig. 6(a), can stabilize the user's walking motion, and furthermore, can effectively teach the user's body such an appropriate walking motion pattern. In addition, since the effect shown in Fig. 9 can be obtained in a healthy person, it can be seen that the device is also effective for users with knee OA. Assistance during the gait cycle between 15% and 50% of the phase can adjust the forward tilt of the lower leg. However, excessive assistance can shift the position of the knee joint relative to the center of gravity, which can cause the knee to become unstable due to the relationship with the floor reaction force, or can result in the user requesting excessive control. In this respect, this embodiment has been proven to reproduce the user's natural walking and forward tilt of the lower leg by providing a free section as in the present invention, and to further stabilize the knee. This leads to the effective functioning of the push-off and the generation of forward propulsion.

[0092] The contents of each of the above-described embodiments can also be specified as follows. (Appendix 1) A control device for a walking motion assist device including at least a motor and a drive mechanism that is rotated by a driving force of the motor and is capable of assisting a rotational motion of an ankle joint of a target leg of a user, an acquisition means for acquiring current phase information capable of identifying a current phase of the target leg in one gait cycle; a control processing means for controlling the driving of the drive mechanism by the motor based on the current phase information; Equipped with The control processing means includes: A plantar flexion control for rotating the drive mechanism in a plantar flexion direction and a dorsiflexion control for rotating the drive mechanism in a dorsiflexion direction are executable based on the current phase information, A free control is executed to set the drive mechanism in a free state in one or both of a first section which is at least a part of a period during which the current phase information indicates a phase corresponding to a sole contact state in a stepping cycle, and a second section which is at least a part of a period during which the current phase information indicates a phase corresponding to a swing leg state in a stepping cycle. A control device for a walking assistance device. (Appendix 2) the control processing means executes, within one walking cycle of the target leg, the free control of the first section following the dorsiflexion control, executes the plantar flexion control and the dorsiflexion control in this order following the free control of the first section, and executes the free control of the second section following the dorsiflexion control. 2. A control device for a walking movement assist device according to claim 1. (Appendix 3) the control processing means continues the free control of the second section while the current phase information indicates a phase corresponding to the swing leg state in a stepping cycle. 3. A control device for a walking movement assist device according to claim 1 or 2. (Appendix 4) The control processing means controls the rotation angle of the drive mechanism so that the rotation angle is larger in the dorsiflexion direction at a start point of the free control in the first section than at a start point of the free control in the second section. 4. A control device for a walking movement assist device according to any one of claims 1 to 3. (Appendix 5) a storage means for storing setting information indicating a time-series rotation pattern of the drive mechanism for one walking cycle of the target leg; Further comprising: The setting information includes, for each of a plurality of set points having mutually different phases during a walking cycle, correspondence information between a phase during the walking cycle and a target rotation angle of the drive mechanism at that phase, The control processing means includes: Executing the dorsiflexion control or the plantar flexion control at each of the plurality of set points based on the current phase information and the setting information so as to achieve a target rotation angle of the set point at a timing corresponding to the phase of the set point; When the target rotation angles of first and second set points, which are adjacent in phase among the plurality of set points in the setting information, are the same, the free control is executed during a period from a timing corresponding to the phase of the first set point to a timing corresponding to the phase of the second set point. 5. A control device for a walking movement assist device according to any one of claims 1 to 4. (Appendix 6) The setting information further includes information indicating a target rotation angle of an end point during a walking cycle, a transmitting means for transmitting the setting information stored in the storing means to a display device so that the information regarding the end point is displayed on the display device; an update means for updating the setting information stored in the storage means so as to indicate a changed target rotation angle of the end point when a user operation for changing the target rotation angle of the end point is performed on the display of the display device; 6. The control device for a walking movement assist device according to claim 5, further comprising: (Appendix 7) the walking motion assist device further includes a detection means capable of detecting a heel-on state, a heel-off state, a toe-on state, and a toe-off state of the target leg, the acquiring means acquiring an elapsed time from a starting point of a walking cycle as the current phase information, and acquiring detection information by the detecting means; The foot flat reference point corresponds to the reference phase in the stride cycle when the toe should turn from the start point to the ground contact point, The control processing means includes: When the first set point is set to correspond to the foot flat reference point in the setting information, the dorsiflexion control is executed so that the target rotation angle of the first set point is reached at a timing corresponding to the phase of the first set point based on the current phase information. When the detection information does not indicate the toe-grounding state at a timing corresponding to the phase of the first set point that can be specified by the current phase information, a fix control for fixing a rotation angle of the drive mechanism or a free control is started. 7. A control device for a walking movement assist device according to claim 5 or 6. (Appendix 8) When the detection information does not indicate the toe-grounded state at a timing corresponding to the phase of the first set point that can be specified by the current phase information, the control processing means continuously executes the free control for a predetermined time length from a timing when the detection information indicates the toe-grounded state, The predetermined time length is a time length between a phase of the first set point and a phase of the second set point set in the setting information. 8. A control device for a walking movement assist device according to claim 7. (Appendix 9) the walking motion assist device further includes a detection means capable of detecting a heel-on state, a heel-off state, a toe-on state, and a toe-off state of the target leg, The control device of the walking motion assist device further comprises a storage means for storing heel-off reference information indicating at least a phase of a heel-off reference point in one walking cycle of the target leg, The heel-off reference point corresponds to a reference phase in a stride cycle when the heel should turn from the sole contact state to the heel-off state, the acquiring means acquiring, as the current phase information, an elapsed time from a reference point prior to a heel-off reference point during a walking cycle, and acquiring detection information by the detecting means; When the detection information indicates the heel-contact state at a timing corresponding to the phase of the heel-off reference point that can be specified by the current phase information, the control processing means starts a fixed control for fixing a rotation angle of the drive mechanism or the free control, and thereafter, when the detection information indicates a change from the heel-contact state to the heel-off state, the control processing means transitions to the dorsiflexion control or the plantar flexion control. 9. A control device for a walking movement assist device according to any one of claims 1 to 8. (Appendix 10) a transmitting means for transmitting the heel-off reference information stored in the storing means to a display device so that the information regarding the heel-off reference point can be displayed on the display device; an update means for updating the heel-off reference information stored in the storage means so as to indicate a phase of the heel-off reference point after a user operation for changing the phase of the heel-off reference point is performed on the display of the display device; 10. The control device for a walking movement assist device according to claim 9, further comprising: (Appendix 11) the walking motion assist device further includes a detection means capable of detecting a heel-on state, a heel-off state, a toe-on state, and a toe-off state of the target leg, the acquiring means acquiring an elapsed time from a reference point in a walking cycle as the current phase information, and acquiring detection information by the detecting means; the control processing means executes a fix control for fixing a rotation angle of the drive mechanism or the free control when the detection information indicates the heel-off state at a timing corresponding to a phase of an end point in a walking cycle that can be specified by the current phase information. 11. A control device for a walking movement assist device according to any one of claims 1 to 10. (Appendix 12) A walking motion assist method executed by a walking motion assist device including a motor, a drive mechanism capable of rotating by a driving force of the motor to assist a rotational motion of an ankle joint of a target leg of a user, an acquisition means for acquiring current phase information capable of identifying a current phase of the target leg in one walking cycle, and a control processing means for controlling driving of the drive mechanism by the motor based on the current phase information, The control processing means Executing a plantar flexion control for rotating the drive mechanism in a plantar flexion direction and a dorsiflexion control for rotating the drive mechanism in a dorsiflexion direction based on the current phase information; A free control is executed to set the drive mechanism in a free state in one or both of a first section which is at least a part of a period during which the current phase information indicates a phase corresponding to a sole contact state in a stepping cycle, and a second section which is at least a part of a period during which the current phase information indicates a phase corresponding to a swing leg state in a stepping cycle. A walking motion assistance method comprising the steps of: (Appendix 13) the control processing means executes, within one walking cycle of the target leg, the free control of the first section following the dorsiflexion control, executes the plantar flexion control and the dorsiflexion control in this order following the free control of the first section, and executes the free control of the second section following the dorsiflexion control. 13. The walking movement assistance method according to claim 12, further comprising: (Appendix 14) the control processing means continues the free control of the second section while the current phase information indicates a phase corresponding to the swing leg state in a stepping cycle; 14. The walking movement assistance method according to claim 12 or 13, further comprising: (Appendix 15) A rotation angle of the drive mechanism is larger in the dorsiflexion direction at a start point of the free control in the first section than at a start point of the free control in the second section. 15. A walking movement assistance method according to any one of appendix 12 to 14. (Appendix 16) the walking motion assist device further includes a storage unit for storing setting information indicating a time-series rotation pattern of the drive mechanism with respect to one walking cycle of the target leg, The setting information includes, for each of a plurality of set points having mutually different phases during a walking cycle, correspondence information between a phase during the walking cycle and a target rotation angle of the drive mechanism at that phase, The dorsiflexion control and the plantar flexion control are executed based on the current phase information and the setting information so that the target rotation angle of each of the plurality of setting points is reached at a timing corresponding to the phase of the setting point, the free control is executed from a timing corresponding to the phase of the first set point to a timing corresponding to the phase of the second set point when the target rotation angles of the first and second set points, which are adjacent in phase among the plurality of set points in the setting information, are the same; 16. A walking movement assistance method according to any one of appendix 12 to 15. (Appendix 17) The setting information further includes information indicating a target rotation angle of an end point during a walking cycle, The walking motion assist device transmitting the setting information stored in the storage means to a display device in order to display information regarding the end point on the display device; when a user operation for changing the target rotation angle of the end point is performed on the display of the display device, the setting information stored in the storage means is updated so as to indicate the changed target rotation angle of the end point. 17. The walking movement assistance method according to claim 16, further comprising: (Appendix 18) the walking motion assist device further includes a detection unit capable of detecting a heel-on state, a heel-off state, a toe-on state, and a toe-off state of the target leg, the current phase information indicates an elapsed time from a starting point in a gait cycle; The foot flat reference point corresponds to the reference phase in the stride cycle when the toe should turn from the start point to the ground contact point, The control processing means When the first set point is set to correspond to the foot flat reference point in the setting information, the dorsiflexion control is executed so that the target rotation angle of the first set point is reached at a timing corresponding to the phase of the first set point based on the current phase information. when the detection information by the detection means does not indicate the toe-grounding state at a timing corresponding to the phase of the first set point that can be specified by the current phase information, a fix control for fixing a rotation angle of the drive mechanism or a free control is started. 18. The walking motion assistance method according to claim 16 or 17. (Appendix 19) When the detection information does not indicate the toe-ground state at a timing corresponding to the phase of the first set point that can be specified by the current phase information, the control processing means continuously executes the free control for a predetermined time length from the timing when the detection information indicates the toe-ground state. Further including: The predetermined time length is a time length between a phase of the first set point and a phase of the second set point set in the setting information. 19. A walking movement assistance method according to claim 18. (Appendix 20) The walking motion assist device further includes a detection means for detecting a heel-on-ground state, a heel-off state, a toe-on-ground state, and a toe-off state of the target leg, and a storage means for storing heel-off reference information indicating at least a phase of a heel-off reference point in one walking cycle of the target leg, The heel-off reference point corresponds to a reference phase in a stride cycle when the heel should turn from the sole contact state to the heel-off state, the current phase information indicates a time elapsed from a reference point prior to a heel-off reference point during a gait cycle; The control processing means When the detection information by the detection means indicates the heel-contact state at a timing corresponding to the phase of the heel-off reference point that can be specified by the current phase information, a fix control for fixing a rotation angle of the drive mechanism or a free control is started; Thereafter, when the detection information indicates a change from the heel-on-ground state to the heel-off state, the control is shifted to the dorsiflexion control or the plantar flexion control. 20. A walking movement assistance method according to any one of appendix 12 to 19. (Appendix 21) The walking movement assist device comprises: transmitting the heel-off reference information stored in the storage means to a display device so that the information regarding the heel-off reference point is displayed on the display device; when a user operation for changing the phase of the heel-off reference point is performed on the display of the display device, the heel-off reference information stored in the storage means is updated so as to indicate the phase of the heel-off reference point after the change. 21. The walking movement assistance method according to claim 20, further comprising: (Appendix 22) the walking motion assist device further includes a detection means capable of detecting a heel-on state, a heel-off state, a toe-on state, and a toe-off state of the target leg, the current phase information indicates an elapsed time from a reference point in a gait cycle; when the detection information by the detection means indicates the heel-off state at a timing corresponding to a phase of an end point in a walking cycle that can be specified by the current phase information, the control processing means executes a fixed control for fixing a rotation angle of the drive mechanism or the free control. 22. The walking movement assistance method according to any one of claims 12 to 21, further comprising: (Appendix 23) The walking movement assist device further includes an output unit, The control processing means causes the output means to perform a notification in a predetermined manner when the current phase indicated by the current phase information acquired by the acquisition means becomes the phase of any one or more of the set points indicated by the setting information. 9. A control device for a walking movement assist device according to any one of Supplementary Note 5 to Supplementary Note 8. (Appendix 24) The walking movement assist device further includes an output means, When the current phase indicated by the current phase information acquired by the acquisition means becomes the phase of one or more of the set points indicated by the setting information, the control processing means causes the output means to perform a notification in a predetermined manner. 20. The walking movement assistance method according to any one of claims 16 to 19, further comprising: [Explanation of symbols]

[0093] 1 Walking motion assistance device (this device), 2 Leg attachment part, 5 Waist attachment part, 10 Control device, 11 CPU, 12 Memory, 13 Input / output I / F, 15 Communication unit, 21 Lower leg brace, 22 Foot brace, 24 Lower leg frame, 25 Foot frame, 26 Connecting shaft, 28 Leg storage box, 30 Motor, 40 Drive mechanism, 51 Waist belt, 52 Waist storage box, 101 Acquisition unit, 102 Holding unit, 103 Control processing unit, 104 UI ​​processing unit, 221 Instep belt, 222 Ankle belt, 226 Toe pressure sensor, 227 Heel pressure sensor, 281 Rotation sensor

Claims

1. A control device for a walking motion assist device including at least a motor and a drive mechanism that is rotated by a driving force of the motor and is capable of assisting a rotational motion of an ankle joint of a target leg of a user, an acquisition means for acquiring current phase information capable of identifying a current phase of the target leg in one gait cycle; a control processing means for controlling the driving of the drive mechanism by the motor based on the current phase information; Equipped with The control processing means includes: A plantar flexion control for rotating the drive mechanism in a plantar flexion direction and a dorsiflexion control for rotating the drive mechanism in a dorsiflexion direction are executable based on the current phase information, A free control is executed to set the drive mechanism in a free state in one or both of a first section which is at least a part of a period during which the current phase information indicates a phase corresponding to a sole contact state in a stepping cycle, and a second section which is at least a part of a period during which the current phase information indicates a phase corresponding to a swing leg state in a stepping cycle. A control device for a walking motion assistance device.

2. the control processing means executes, within one walking cycle of the target leg, the free control of the first section following the dorsiflexion control, executes the plantar flexion control and the dorsiflexion control in this order following the free control of the first section, and executes the free control of the second section following the dorsiflexion control. The control device for a walking movement assist device according to claim 1 .

3. the control processing means continues the free control of the second section while the current phase information indicates a phase corresponding to the swing leg state in a stepping cycle. The control device for a walking movement assist device according to claim 2.

4. The control processing means controls the rotation angle of the drive mechanism so that the rotation angle is larger in the dorsiflexion direction at a start point of the free control in the first section than at a start point of the free control in the second section. The control device for a walking movement assist device according to any one of claims 1 to 3.

5. a storage means for storing setting information indicating a time-series rotation pattern of the drive mechanism for one walking cycle of the target leg; Further comprising: The setting information includes, for each of a plurality of set points having mutually different phases during a walking cycle, correspondence information between a phase during the walking cycle and a target rotation angle of the drive mechanism at that phase, The control processing means includes: Executing the dorsiflexion control or the plantar flexion control at each of the plurality of set points based on the current phase information and the setting information so as to achieve a target rotation angle of the set point at a timing corresponding to the phase of the set point; When the target rotation angles of first and second set points, which are adjacent in phase among the plurality of set points in the setting information, are the same, the free control is executed during a period from a timing corresponding to the phase of the first set point to a timing corresponding to the phase of the second set point. The control device for a walking movement assist device according to claim 1 .

6. The setting information further includes information indicating a target rotation angle of an end point during a walking cycle, a transmitting means for transmitting the setting information stored in the storing means to a display device so that the information regarding the end point is displayed on the display device; an update means for updating the setting information stored in the storage means so as to indicate a changed target rotation angle of the end point when a user operation for changing the target rotation angle of the end point is performed on the display of the display device; The control device for a walking movement assist device according to claim 5 , further comprising:

7. the walking motion assist device further includes a detection means capable of detecting a heel-on state, a heel-off state, a toe-on state, and a toe-off state of the target leg, the acquiring means acquiring an elapsed time from a starting point of a walking cycle as the current phase information, and acquiring detection information by the detecting means; The foot flat reference point corresponds to the reference phase in the stride cycle when the toe should turn from the start point to the ground contact point, The control processing means includes: When the first set point is set to correspond to the foot flat reference point in the setting information, the dorsiflexion control is executed so that the target rotation angle of the first set point is reached at a timing corresponding to the phase of the first set point based on the current phase information. When the detection information does not indicate the toe-grounding state at a timing corresponding to the phase of the first set point that can be specified by the current phase information, a fix control for fixing a rotation angle of the drive mechanism or a free control is started. The control device for a walking movement assist device according to claim 5 or 6.

8. When the detection information does not indicate the toe-grounded state at a timing corresponding to the phase of the first set point that can be specified by the current phase information, the control processing means continuously executes the free control for a predetermined time length from a timing when the detection information indicates the toe-grounded state, The predetermined time length is a time length between a phase of the first set point and a phase of the second set point set in the setting information. The control device for a walking movement assist device according to claim 7.

9. the walking motion assist device further includes a detection unit capable of detecting a heel-on state, a heel-off state, a toe-on state, and a toe-off state of the target leg, The control device of the walking motion assist device further comprises a storage means for storing heel-off reference information indicating at least a phase of a heel-off reference point in one walking cycle of the target leg, The heel-off reference point corresponds to a reference phase in a stride cycle when the heel should turn from the sole contact state to the heel-off state, the acquiring means acquiring, as the current phase information, an elapsed time from a reference point prior to a heel-off reference point during a walking cycle, and acquiring detection information by the detecting means; When the detection information indicates the heel-contact state at a timing corresponding to the phase of the heel-off reference point that can be specified by the current phase information, the control processing means starts a fixed control for fixing a rotation angle of the drive mechanism or the free control, and thereafter, when the detection information indicates a change from the heel-contact state to the heel-off state, the control processing means transitions to the dorsiflexion control or the plantar flexion control. The control device for a walking movement assist device according to claim 1 .

10. a transmitting means for transmitting the heel-off reference information stored in the storing means to a display device so that the information regarding the heel-off reference point is displayed on the display device; an update means for updating the heel-off reference information stored in the storage means so as to indicate a phase of the heel-off reference point after a user operation for changing the phase of the heel-off reference point is performed on the display of the display device; The control device for a walking movement assist device according to claim 9, further comprising:

11. the walking motion assist device further includes a detection unit capable of detecting a heel-on state, a heel-off state, a toe-on state, and a toe-off state of the target leg, the acquiring means acquiring an elapsed time from a reference point in a walking cycle as the current phase information, and acquiring detection information by the detecting means; the control processing means executes a fix control for fixing a rotation angle of the drive mechanism or the free control when the detection information indicates the heel-off state at a timing corresponding to a phase of an end point in a walking cycle that can be specified by the current phase information. The control device for a walking movement assist device according to claim 1 .

12. A walking motion assist method executed by a walking motion assist device including a motor, a drive mechanism capable of rotating by a driving force of the motor to assist a rotational motion of an ankle joint of a target leg of a user, an acquisition means for acquiring current phase information capable of identifying a current phase of the target leg in one walking cycle, and a control processing means for controlling driving of the drive mechanism by the motor based on the current phase information, The control processing means Executing a plantar flexion control for rotating the drive mechanism in a plantar flexion direction and a dorsiflexion control for rotating the drive mechanism in a dorsiflexion direction based on the current phase information; A free control is executed to set the drive mechanism in a free state in one or both of a first section which is at least a part of a period during which the current phase information indicates a phase corresponding to a sole contact state in a stepping cycle, and a second section which is at least a part of a period during which the current phase information indicates a phase corresponding to a swing leg state in a stepping cycle. A walking motion assistance method comprising the steps of:

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