Assistive devices

Abstract

An assistive device includes a first wearable unit (11), a second wearable unit (12L, 12R), an actuator (9), a detection unit, and a controller. The controller is configured to obtain assist parameters for causing the actuator (9) to generate a desired assistive force, and to perform control for causing the actuator (9) to operate in accordance with the output corresponding to the assist parameters. When a user performs a forward leaning motion, the controller obtains assist parameters for providing an assistive force to the user in the direction that enables the user to achieve an upright posture, based on the tilt angle and a time-based change in the tilt angle. The controller is configured to further perform assist reduction processing to decrease the assistive force when the time-based change in the tilt angle increases.

Description

Technical Field

[0001] This disclosure relates to auxiliary devices. Background Technology

[0002] Various assistive devices have been proposed that are worn on a user's body to assist the user in performing a task. For example, when lifting or lowering heavy objects, the user of the assistive device can perform the task with less force (with less burden). Among such assistive devices, there are known devices that include: a first wearable unit worn on the user's upper body, a right second wearable unit worn on the user's right leg and a left second wearable unit worn on the user's left leg, and an actuator that provides assistive force to the user through the first wearable unit and the second wearable unit (see, for example, Japanese Unexamined Patent Application Publication No. 2019-206044 (JP 2019-206044 A)). Summary of the Invention

[0003] When lifting a load, the user changes his or her posture from a leaning position to an upright position. In this case, the assistive device disclosed in JP 2019-206044 A generates an assistive force (assistive torque) in the direction that brings the upper body from a leaning position to an upright position. When the user lowers the load, i.e., when the user places a load held in their hands on the floor or the like, the user changes his or her posture from an upright position to a leaning position. Again, in this case, the assistive device generates an assistive force (assistive torque) in the direction that brings the upper body from a leaning position to an upright position. Therefore, the assistive device generates an assistive force that slows down (brakes) the user's movement of leaning forward to lower the load.

[0004] Preferably, the assistive force generated by the assistive device varies according to, for example, the tilt angle of the upper body. For instance, when a user tilts his or her upper body forward to a large extent while maintaining a load, a large burden is placed on his or her hips. Therefore, it is preferable that the assistive device should generate a larger assistive force when the tilt angle of the upper body is large compared to when the tilt angle is small. Thus, the burden on the user's hips can be reduced more effectively.

[0005] To achieve this, the auxiliary device disclosed in JP 2019-206044 A obtains an auxiliary torque command value as an auxiliary parameter for causing the actuator to generate the desired auxiliary force, and performs control to cause the actuator to operate with an output corresponding to the command value. When the user leans his or her upper body forward to the maximum extent, the auxiliary device sets the command value to the maximum value.

[0006] As described above, when a user adopts a forward-leaning posture, the assistive device generates an assist torque in the direction that brings the upper body from the forward-leaning posture to an upright posture. Therefore, when a user leans their upper body forward to a large extent, temporarily stops the movement, and then leans their upper body further forward, the already set large assist torque command value makes it difficult for the user to take a further forward-leaning posture. If the command value is set to generate a small assist torque even at a large angle of upper body tilt, the user can easily take a further forward-leaning posture after temporarily stopping the forward-leaning movement. However, in this case, the assist force may be insufficient, and therefore, for example, it may be less effective at relieving the load on the hips.

[0007] This disclosure provides an assistive device that increases the assistive force as the user tilts their upper body forward at an increasing angle, and allows the user to easily move both sides when the user tilts further forward from that position.

[0008] An assistive device according to one aspect of this disclosure includes: a first wearable unit worn on the upper body of a user; left and right second wearable units worn on the user's left and right legs, respectively; an actuator configured to provide assistive force to the user through the first and second wearable units; a detection unit configured to detect the tilt angle of the user's upper body; and a controller configured to: obtain assistive parameters for causing the actuator to generate a desired assistive force, and perform control to cause the actuator to operate with an output corresponding to the assistive parameters. When the user performs a forward leaning motion, the controller obtains assistive parameters for providing assistive force to the user in the direction that enables the user to achieve an upright posture, based on the tilt angle and a time-based change in the tilt angle. The controller is configured to: further perform assist reduction processing to decrease the assistive force when the time-based change in the tilt angle increases.

[0009] This assistive device uses the tilt angle of the user's upper body to obtain assistive parameters. Therefore, compared to when the tilt angle is small, the assistive device can generate a greater assistive force when the upper body is tilted forward to a large extent and at a large tilt angle. Thus, for example, the burden on the user's hips can be reduced more effectively. Furthermore, the assistive parameters are obtained not only using the tilt angle of the user's upper body but also using the time-based change in the tilt angle. In particular, processing is performed to reduce the assistive force as the time-based change in the tilt angle increases. Therefore, if the user tilts their upper body forward to a relatively large extent, temporarily stops the movement, and then tilts their upper body forward further, the assistive force can be reduced based on the time-based change in the tilt angle when the upper body begins to move, allowing the user to easily take a further forward tilt posture.

[0010] The controller can be configured to perform a first process to increase the auxiliary force when the tilt angle increases, and to perform a second process as an auxiliary weakening process to reduce the auxiliary force when the time-based change in the tilt angle increases, and to obtain auxiliary parameters based on the results of the first and second processes.

[0011] In this configuration, the assistive force increases when the user performs a load-reducing action, such as when the upper body tilt angle increases. When the user stops in a forward-leaning posture at a predetermined tilt angle, the time-based change in the tilt angle becomes zero, and the forward-leaning posture is maintained by a relatively large assistive force to reduce the burden on the user. As the user begins to tilt forward further and the time-based change in the tilt angle increases, an assist parameter is obtained in the direction of decreasing the assistive force. Therefore, the user can easily adopt a forward-leaning posture.

[0012] The controller can be configured to further perform the following processing as a second process: obtain the acceleration or deceleration of the user's forward leaning motion, and reduce the assist force by a greater rate when acceleration is obtained than when deceleration is obtained.

[0013] In this configuration, even when the time-based change in tilt angle is the same during the user's forward leaning motion, the assistance parameters obtained when the forward leaning motion involves acceleration differ from those obtained when the forward leaning motion involves deceleration. Therefore, when the forward leaning motion involves acceleration, for example, when the user quickly lowers a relatively light load, the ratio of the reduction in the assistance force in the direction leading the user to an upright posture increases, and thus, the user can more easily perform the forward leaning motion. In contrast, when the forward leaning motion involves deceleration, for example, when the user slowly lowers a heavy load, the ratio of the reduction in the assistance force in the direction leading the user to an upright posture decreases, and thus, an appropriate assistance force can be provided to the user.

[0014] As one configuration of the assistive device, the actuator may include: a drive unit mounted on a first body-worn unit to the left and right sides of the user's hip; and arms, each arm having a front end mounted on a corresponding one of a second body-worn unit worn on the thigh of the user's leg, and a base end mounted on a corresponding one of the drive unit, each arm being configured to swing back and forth about the base end. The actuator may be configured to provide the user with an assistive force in the opposite direction to the forward leaning direction by generating torque on the arm about the base end when the user changes the posture of their upper body in a forward leaning direction.

[0015] For example, when a user lowers the load—that is, when the user places a load held in their hands on the floor or similar surface—the user changes their posture from an upright position to a forward-leaning position. In the above configuration, the assistive device can generate an assistive force in the direction that brings the upper body from the forward-leaning position back to an upright position. In other words, the assistive device can generate an assistive force that slows down the user's forward-leaning movement.

[0016] As another configuration of the auxiliary device, the actuator may include: a winding unit comprising a roller and a motor for rotating the roller, the winding unit being mounted on a first wearable unit; and a belt having a first end wound around the roller and a second end mounted on a second wearable unit. The actuator may be configured to generate torque via the motor in the direction in which the roller winds a portion of the belt. The actuator may be configured to wind the belt off the roller simultaneously, generating torque in the direction of winding the belt onto the roller, when the user changes their upper body posture in a forward-leaning direction.

[0017] For example, when a user lowers the load—that is, when the user places a load held in their hands on the floor or similar surface—the user changes their posture from an upright position to a forward-leaning position. In the above configuration, the assistive device can generate an assistive force in the direction that brings the upper body from the forward-leaning position back to an upright position. In other words, the assistive device can generate an assistive force that slows down the user's forward leaning of their upper body.

[0018] The auxiliary device according to the present disclosure can increase the assistive force when the user's upper body tilts forward at an increased angle, and enable the user to easily move both when the user tilts forward further from that state. Attached Figure Description

[0019] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and in the drawings:

[0020] Figure 1 This is a perspective view showing the overall configuration of an example of the auxiliary device;

[0021] Figure 2 yes Figure 1 An exploded perspective view of the auxiliary device shown;

[0022] Figure 3 It shows the user wearing Figure 1 Side view of the auxiliary device shown;

[0023] Figure 4 It shows the user wearing Figure 1Side view of the auxiliary device shown;

[0024] Figure 5 This is an exploded view of the right actuator;

[0025] Figure 6 This is a cross-sectional view of the right actuator;

[0026] Figure 7 It is a block diagram showing control devices, etc., included in the auxiliary device;

[0027] Figure 8 This is a block diagram illustrating a portion of the reduced motion processing;

[0028] Figure 9 This is a flowchart illustrating an example of reducing motion processing;

[0029] Figure 10 This is a diagram illustrating an example of the virtual spring constant and damper constant;

[0030] Figure 11 It is a graph showing the auxiliary torque command value;

[0031] Figure 12 This is a diagram illustrating an example of a modification in the second process;

[0032] Figure 13 This is a perspective view showing the second form of the auxiliary device;

[0033] Figure 14 It is shown Figure 8 A block diagram illustrating a modified example of the processing;

[0034] Figure 15 It is a perspective view showing the third form of the auxiliary device; and

[0035] Figure 16 This is a diagram of a winding unit. Detailed Implementation

[0036] Overall structure of auxiliary device

[0037] Figure 1 This is a perspective view showing the overall construction of an example of an auxiliary device. Figure 2 yes Figure 1 An exploded perspective view of the auxiliary device shown. Figure 3 and Figure 4 It shows the user wearing Figure 1 A side view of the auxiliary device shown. Figure 3 In the middle, the user is in an upright posture, and Figure 4 In the middle, the user is in a forward-leaning posture. Figure 3The upright posture shown is a posture in which the user's body is in a longitudinal direction along a vertical line V from his or her legs BL to his or her head BH. Figure 4 The forward-leaning posture shown is one in which the user's upper body is tilted forward relative to the vertical line V. The upper body is the portion from the hips (BW) to the head (BH). Figure 4 The forward-leaning posture shown is the posture of a user who has already bent his or her leg at the knee joint. Figure 4 In this context, the angle of the user's upper body leaning forward relative to the vertical line V is represented by θh. The angle θh represents the "tilt angle θh" of the user's upper body relative to the vertical line V.

[0038] The assistive device 10 is a device that, for example, assists the user in rotating his or her leg BL (thigh BF) relative to his or her hip BW when lifting and lowering the load, and assists the user in rotating his or her leg BL (thigh BF) relative to his or her hip BW when walking. The operation in which the assistive device 10 provides physical assistance to the user will be referred to as "assistive operation".

[0039] In the attached diagram, the X, Y, and Z axes are orthogonal to each other. For a user wearing the assistive device 10 in an upright posture, the X, Y, and Z axes correspond to the forward, left, and upward directions, respectively. Regarding the assistive operation, as mentioned above, the assistive user rotating his or her leg BL (thigh BF) relative to his or her hip BW is the same as the assistive user rotating his or her hip BW relative to his or her leg BL (thigh BF). In this embodiment, the assistive operation is achieved by providing the user with a torque around an imaginary line Li, which passes through the user in the left-right direction near the user's hip BW. This torque will also be referred to as the "assistive torque".

[0040] Figure 1 The illustrated assistive device 10 includes: a first wearable unit 11; a right second wearable unit 12R; a left second wearable unit 12L; and an actuator 9 that generates an assistive torque to assist the user in moving his or her hip BW relative to his or her thigh BF and vice versa. "Moving his or her hip BW relative to his or her thigh BF and vice versa" means moving his or her thigh BF relative to his or her hip BW and vice versa. Figure 1 In the form shown, the actuator 9 includes a right drive unit 13R and a left drive unit 13L, and arms 37 respectively mounted on the drive units 13R and 13L.

[0041] The first wearable unit 11 includes a hip support 21 and a sleeve 22, and is worn on the upper body of the user, including at least his or her hip (BW). The right second wearable unit 12R and the left second wearable unit 12L are worn on the thigh (BF) of the user's right leg (BL) and left leg (BL). The right drive unit 13R and the left drive unit 13L are inserted between the first wearable unit 11 and the second wearable units 12R and 12L, and serve as drive units for performing drive operations to perform auxiliary operations.

[0042] The auxiliary device 10 also includes an operation unit 14 and a control device 15. The operation unit 14 is a controller, where the user inputs specifications such as those for the auxiliary operation. These specifications include the operation mode, intensity, and speed of the auxiliary operation. Operation modes include, for example, "lowering" and "raising." "Walking" may also be included. The intensity of the auxiliary operation is set to multiple levels, such as "Level 1 (Low)," "Level 2 (Medium)," and "Level 3 (High)." The operation unit 14 is equipped with selection buttons, allowing the user to select the appropriate auxiliary operation level. The operation unit 14 and the control device 15 are connected to each other via wired or wireless means and can communicate with each other. The control device 15 controls the operation of the drive units 13R and 13L based on the information input to the operation unit 14.

[0043] The first wearable unit 11 includes a hip support 21, a sheath 22, a frame 23, and a backpack 24. The hip support 21 is worn around the user's hips (BW). The hip support 21 includes a strap 25. The strap 25 allows for changing the length of the hip support 21 around the hips (BW) and is used to secure the hip support 21 to the hips (BW). The hip support 21 includes a hard core made of resin or the like, and leather or fabric components. The housings 36 of the drive units 13R and 13L are mounted on the right and left sides of the hip support 21. The hip support 21 and housings 36 are mounted so that they can rotate in one direction and the other about an imaginary line Li extending in the left-right direction. The sheath 22 is worn around the user's shoulders (BS) and chest (BB). The sheath 22 includes a hard core made of resin or the like, and leather or fabric components. The sheath 22 is coupled to the frame 23 and the hip support 21.

[0044] Frame 23 is formed from components made of a metal such as aluminum alloy. Frame 23 includes a main frame 28, a left sub-frame 29L, and a right sub-frame 29R. The main frame 28 includes a support member 30 against which the user's back rests. The right sub-frame 29R and the left sub-frame 29L are columnar members that connect the main frame 28 to a portion of the right drive unit 13R and a portion of the left drive unit 13L. Therefore, the right drive unit 13R and the left drive unit 13L are integral with the frame 23 of the first wearable unit 11, and thus, the right drive unit 13R and the left drive unit 13L cannot be displaced relative to each other with respect to the frame 23 (first wearable unit 11).

[0045] Backpack 24 is mounted at the rear of the main frame 28. Backpack 24 is also called a control box and has a box shape. Inside backpack 24 are a control device 15, a power source (battery) 20, an acceleration sensor 33, and other devices. Power source 20 supplies the required power to multiple devices, including control device 15, right drive unit 13R, and left drive unit 13L.

[0046] The right second-body wearable unit 12R and the left second-body wearable unit 12L are worn around the user's right thigh bone (BF) and left thigh bone (BF). The shape of the second-body wearable unit 12L for the left thigh bone (BF) and the shape of the second-body wearable unit 12R for the right thigh bone (BF) are mirror images of each other, but the two units have the same construction. The second-body wearable unit 12L (12R) includes a pad-shaped main body 31 formed from a hard core made of metal, resin, etc., and a strap 32 formed from a leather or fabric component. A portion of the arm 37 of the drive unit 13L is coupled to the main body 31. The main body 31 contacts the front surface of the thigh bone (BF). The strap 32 allows for changing the length of the second-body wearable unit 12R (12L) around the thigh bone (BF) and is used to secure the main body 31 to the thigh bone (BF).

[0047] The right drive unit 13R and the left drive unit 13L are mounted on the first wearable unit 11, positioned to the right and left of the user's hip (BW). Specifically, drive units 13R and 13L are mounted to the right and left of the hip support 21. The shape of the left drive unit 13L is a mirror image of the shape of the right drive unit 13R, but the two units have the same construction and the same function. The left drive unit 13L and the right drive unit 13R can operate independently of each other and perform different operations, or they can perform the same operation synchronously.

[0048] Each of the right drive unit 13R and the left drive unit 13L has a configuration for performing an auxiliary operation that provides assistance to the user. The assistance force is a force based on torque about an imaginary line Li, and this torque is an "assistance torque". The assistance device 10 uses the assistance torque output by the right drive unit 13R and the left drive unit 13L to assist the user in rotating his or her thigh BF relative to his or her hip BW.

[0049] Figure 5 This is an exploded view of the right drive unit 13R. Figure 6 This is a cross-sectional view of the right drive unit 13R. Since the left drive unit 13L and the right drive unit 13R have the same construction, the construction of the right drive unit 13R will be described, and the description of the left drive unit 13L will be omitted here. The drive unit 13R includes a drive mechanism 35 and a housing 36 that houses the drive mechanism 35. The torque output from the drive mechanism 35 is transmitted to the arm 37. Figure 5 and Figure 6 In the image, only a portion of arm 37 (first arm portion 37a) is shown.

[0050] The auxiliary shaft 38 is fixed to the upper end of the arm 37 (first arm portion 37a), and the arm 37 and the auxiliary shaft 38 rotate integrally. The auxiliary shaft 38 is configured in the drive unit 13R with an imaginary line Li as its center. Figure 1 As shown, the front end of arm 37 (third arm portion 37c) is coupled to the second wearable unit 12R.

[0051] The drive mechanism 35 is constructed as follows. The drive mechanism 35 provides auxiliary torque to the user by causing the arm 37 to swing (rotate) about an imaginary line Li. This is achieved when the user voluntarily changes his or her posture (see...). Figure 3 and Figure 4 Arm 37 swings (rotates) relative to housing 36 about imaginary line Li.

[0052] The specific construction of the drive mechanism 35 will be described. For example... Figure 5 and Figure 6As shown, the drive mechanism 35 includes: a subframe 41 fixed to a housing 36; a motor 42; a reducer 43; a first pulley 44 with a flange 44a; a drive belt 45; a second pulley 46; a coil spring 47; a bearing 48; a first detector 51; and a second detector 52. The motor 42, reducer 43, and second detector 52 are mounted on the subframe 41. The first pulley 44 is mounted on the output shaft 42a of the motor 42 via the bearing 48, and the first pulley 44 is rotatable relative to the output shaft 42a. The inner peripheral end of the coil spring 47 is mounted on the front portion of the output shaft 42a. The outer peripheral end of the coil spring 47 is mounted on the flange 44a of the first pulley 44. An auxiliary shaft 38 is fixed to the reduction shaft 43b of the reducer 43. The second pulley 46 is mounted on the speed-increasing shaft 43a of the reducer 43. A drive belt 45 is wound around the first pulley 44 and the second pulley 46. The central axes of the auxiliary shaft 38, the reducer 43, and the second pulley 46 coincide with the imaginary line Li.

[0053] The housing 36 has a separate structure. The housing 36 includes an outer shell 54, a middle shell 55, and an inner shell 56. The inner shell 56 is mounted on the hip support 21, allowing it to rotate about an imaginary line Li. An auxiliary shaft 38 is arranged to extend through a hole 54a provided in the outer shell 54.

[0054] The first detector 51 detects the rotation angle of the output shaft 42a of the motor 42. The second detector 52 directly detects the rotation angle of the second pulley 46. Since the reduction ratio of the reducer 43 is constant, the second detector 52 can detect the rotation angle of the auxiliary shaft 38. The rotation angle of the auxiliary shaft 38 is the same as the swing angle (rotation angle) of the arm 37, and therefore the second detector 52 can detect the swing angle of the arm 37.

[0055] exist Figure 3 In the upright posture shown, the straight line LB along the longitudinal direction of the user's upper body and the straight line LF along the longitudinal direction of the user's thigh BF extend along a common vertical line V. For example... Figure 4 As shown, in a posture where the user leans forward by bending his or her knees, the straight line LB is tilted relative to the vertical line V, and the angle of this tilt is "tilt angle θh". The straight line LB in the longitudinal direction of the user's upper body and the straight line LF in the longitudinal direction of the user's thigh BF intersect each other at an angle θL. Since the arm 37 is set along the user's thigh BF, the angle formed by the user's upper body and thigh BF is the same as the swing angle of the arm 37. In other words, angle θL represents the tilt angle of the upper body relative to the thigh BF.

[0056] Therefore, the second detector 52 can be used as a detection unit to detect the tilt angle (θL) of the user's upper body relative to the user's thigh BF. In the following text, the tilt angle of the user's upper body can be used as the angle (θh) of the upper body relative to the vertical line V, or the angle (θL) of the upper body relative to the thigh BF. The tilt angle (θh, θL) can be based on the state at the time when the assistive device 10 begins assistive operation.

[0057] Figure 5 The second detector 52 of the drive unit 13R shown can obtain swing angle information about the swing angle θL of the arm 37 relative to the straight line LB in the longitudinal direction of the user's upper body. The second detector 52 is used as a swing angle detection unit to obtain swing angle information about the swing angle θL of the arm 37. Since the swing angle θL of the arm 37 corresponds to the rotation angle (swing angle) of the femur relative to the pelvis, the swing angle θL of the arm 37 can be referred to not only as the tilt angle of the user's upper body, but also as the rotation angle of the user's hip joint.

[0058] The first detector 51 and the second detector 52 are formed by an encoder, an angle sensor, etc. The first detector 51 and the second detector 52 are disposed in each of the drive units 13R and 13L, and serve as detectors for the thigh BF of the right leg and the thigh BF of the left leg, respectively. The detection results of the first detector 51 and the second detector 52 are output to the control device 15. The detection result of each first detector 51 should be rotation angle information about the rotation angle of the output shaft 42a, and in this embodiment, this information is the rotation angle itself. The detection result of each second detector 52 should be swing angle information about the swing angle of the arm 37, and in this embodiment, this information is the swing angle θL itself.

[0059] As described above (see Figure 1 The frame 23 of the first wearable unit 11 is integral with the right drive unit 13R and the left drive unit 13L and cannot be displaced relative to each other. When the user changes his or her posture (see...), Figure 3 and Figure 4 The right arm 37 and left arm 37 rotate about an imaginary line Li relative to the housing 36 of the right drive unit 13R and left drive unit 13L. Therefore, when the user changes his or her posture, torque is applied to the arm 37. This torque is transmitted from each arm 37 to the second pulley 46 via the auxiliary shaft 38 and the reducer 43. The torque transmitted to the second pulley 46 is transmitted to the coil spring 47 via the drive belt 45 and the first pulley 44. The torque transmitted from the arm 37 to the auxiliary shaft 38 due to the user's change in posture accumulates in the coil spring 47.

[0060] When motor 42 rotates, the torque of motor 42 (motor torque) accumulates in coil spring 47. Therefore, the torque of motor 42, as well as the torque transmitted by the user's action, accumulates in coil spring 47. The combined torque of the auxiliary torque and the user's torque is accumulated in coil spring 47. The combined torque accumulated in coil spring 47 is output to auxiliary shaft 38 via first pulley 44, drive belt 45, second pulley 46, and reducer 43, causing arm 37 to swing. The torque output by drive units 13R and 13L using the torque of motor 42 is the "auxiliary torque" provided by auxiliary device 10. As described later, the command value of the auxiliary torque output by drive units 13R and 13L is obtained by control device 15, and actuator 9 operates with an output corresponding to this auxiliary torque command value.

[0061] The combined torque is obtained based on the angular change of the coil spring 47 from its no-load state and the spring constant of the coil spring 47. The angular change is related to the sum of the angular change of the output shaft 42a of the motor 42 and the angular change of the auxiliary shaft 38. Therefore, the combined torque is obtained based on the detection results of the first detector 51, the detection results of the second detector 52, and the spring constant of the coil spring 47. Since the detection results of the first detector 51 and the detection results of the second detector 52 are provided to the processing unit 16 included in the control device 15, the processing unit 16 can obtain the combined torque.

[0062] like Figure 1 and Figure 2 As shown, each arm 37 includes multiple arm portions and connectors that couple these arm portions together. In this disclosure, each arm 37 includes a first arm portion 37a, a second arm portion 37b, a third arm portion 37c, a first connector 39a, and a second connector 39b. Arm 37 includes connectors 39a and 39b, but can transmit torque around an imaginary line Li to a second wearable unit 12R (12L). This is achieved when the user changes his or her posture (see...). Figure 3 and Figure 4 The second wearable unit 12R (12L) is pressed by the thigh BF, and the arm 37 swings around the imaginary line Li. Therefore, the arm 37 can transmit the force (change of posture) exerted by the user on the second wearable unit 12R (12L) to the auxiliary shaft 38 as a torque around the imaginary line Li. The arm 37 may have a different form than that shown in the figures.

[0063] The auxiliary device 10 also includes a detection unit for detecting the tilt angle of the user's upper body, which is the upper part of the user's body including his or her hip BW. In this embodiment, the detection unit is a triaxial accelerometer 33. The accelerometer 33 is, for example, disposed in the backpack 24. The tilt angle of the user's upper body detected by the accelerometer 33 is the tilt angle of the user's upper body relative to the vertical line V when the user's upper body tilts forward, and in this disclosure (see [link to documentation]). Figure 4 The tilt angle is represented by "θh" as described above. The detection unit can have other forms, as long as it is configured to output a signal corresponding to the user's upper body posture (tilt angle) like a three-axis accelerometer 33.

[0064] As described above, the tilt angle of the upper body relative to the thigh (BF) is detected by the second detector 52. Although the detection unit for detecting the tilt angle of the upper body can be the second detector 52, in this embodiment, the case in which the detection unit is a triaxial accelerometer 33 will be described.

[0065] Figure 7 This is a block diagram showing a control device 15, etc., included in the auxiliary device 10. The control device 15 receives an auxiliary torque command value as an auxiliary parameter for determining the auxiliary force (auxiliary torque) to be generated, and performs control to cause the actuator 9 to operate with an output based on the command value. The auxiliary parameter can be any parameter that determines the auxiliary torque to be generated, and parameters other than torque, such as auxiliary force, can be used as auxiliary parameters.

[0066] In order to obtain the auxiliary torque command value and control the actuator 9, the control device 15 includes a processing unit (processing device) 16 with a central processing unit (CPU), a storage device 17 formed by non-volatile memory storing information such as various programs and databases, a motor driver 18, and a communication interface 19.

[0067] The processing unit 16 can have various functions by executing a computer program stored in the storage device 17. The processing unit 16 is used to acquire an auxiliary torque command value as an auxiliary parameter and to provide commands for performing auxiliary operations using the drive units 13R and 13L. Specifically, as a functional unit operating according to the computer program stored in the storage device 17, the processing unit 16 includes a calculation unit 16a for acquiring the auxiliary torque command value and an action determination unit 16b for determining the user's action (action pattern). The action determination unit 16b automatically determines the user's action based on the detection results of one or both of the triaxial accelerometer 33 and the second detector 52.

[0068] The functions of the commands given for performing auxiliary operations using drive units 13R and 13L will be described. For example, when the user selects operation unit 14 (see...) Figure 7 When a user selects a button (e.g., a button corresponding to the selected button), the processing unit 16 performs an auxiliary operation according to a program for the action corresponding to that button. The processing unit 16 performs auxiliary operations for actions such as "lowering" and "raising" according to programs stored in the storage device 17. When "walking" is detected as an action mode, the processing unit 16 performs auxiliary operations for "walking" according to programs stored in the storage device 17. The walking program, raising program, and lowering program are stored as programs in the storage device 17. For example, when a user selects the button corresponding to "lowering" in the operation unit 14, the processing unit 16 performs an auxiliary operation for lowering according to the lowering program.

[0069] When the auxiliary device 10 provides assistance for each of the actions of "walking," "lifting," and "lowering," the processing unit 16 obtains a command value for the required auxiliary torque and generates a command signal that causes the drive units 13R and 13L to output an auxiliary torque corresponding to the command value. This command signal is provided to the motor driver 18. The motor driver 18 is configured to include, for example, electronic circuitry and outputs a drive current for driving the motor 42 based on the command signal from the processing unit 16. The motor driver 18 activates the drive units 13R and 13L based on the command signal. The motor driver 18 serves as an activation control unit for activating the drive units 13R and 13L based on a signal (command signal) corresponding to the auxiliary torque command value.

[0070] Signals from each of the operation unit 14, the first detector 51, the second detector 52, and the accelerometer 33 are input to the communication interface 19, which then provides these signals to the processing unit 16. Information input to the operation unit 14, such as specifications for auxiliary operations, is input to the processing unit 16 via the communication interface 19, and the processing unit 16 uses the input information to perform processing.

[0071] Overview of auxiliary operations

[0072] As described above, the assistive device 10 performs assistive operations using arm 37 by operating the right drive unit 13R and the left drive unit 13L. The assistive operation is the operation of providing the user with assistive torque around an imaginary line Li by the first wearable unit 11 and the second wearable units 12R, 12L, which passes through the user in the left-right direction near his or her hip BW.

[0073] Examples of user actions include: lifting actions (also known as "standing actions"), in which the user changes his or her upper body posture from a leaning position to an upright position to lift the load; lowering actions (also known as "leaning actions"), in which the user changes his or her upper body posture from an upright position to a leaning position to lower the load; and actions in which the user walks.

[0074] Regardless of whether the user performs a lifting or lowering motion, the auxiliary torque generated by the assistive device 10 is a torque in the direction that changes the user's posture from a forward-leaning posture to an upright posture. That is, the right drive unit 13R and the left drive unit 13L attempt to make the arm 37 rotate around an imaginary line Li (see...). Figure 4 The direction of rotation (swing) is the direction of arrow R1, and the direction in which the right drive unit 13R and the left drive unit 13L attempt to rotate the first body wearing unit 11 (frame 23) around the imaginary line Li is the direction of arrow R2.

[0075] When the user performs a lifting or lowering motion, the pad-shaped main body 31 of the right second-body wearable unit 12R and the left second-body wearable unit 12L pushes the right thigh BF and left thigh BF backward with an auxiliary torque in the direction of arrow R1. The frame 23 of the first-body wearable unit 11 pulls the user's upper body backward with an auxiliary torque in the direction of arrow R2. In the case of a lifting motion, the user changes his or her posture to an upright posture in the direction in which the auxiliary torque acts. In the case of a lowering motion, the user changes his or her posture to a forward-leaning posture in the opposite direction to the direction in which the auxiliary torque acts. Therefore, the assistive device 10 generates an auxiliary torque as an assistive force to slow down (brake) the user's forward-leaning upper body movement to reduce the load. Furthermore, when the user stops in the forward-leaning posture, the posture is maintained by the generated auxiliary torque, and the burden on his or her body is reduced.

[0076] When the assistive device 10 performs an assistive operation for the user to walk, the assistive operation is to assist the user in rotating his or her thigh BF relative to his or her hip BW, and the right drive unit 13R and the left drive unit 13L alternately perform this operation to assist the rotation. Therefore, the right drive unit 13R and the left drive unit 13L alternately swing the right arm 37 and the left arm 37 with a predetermined assist torque.

[0077] Processing performed by control device 15

[0078] The command value of the auxiliary torque output by the drive units 13R and 13L for performing auxiliary operations on the auxiliary device 10 configured as described above is determined by the calculation unit 16a of the processing unit 16. The torque provided to the user by the actuator 9 is based on the output torque of the motor 42. To increase the auxiliary torque provided to the user, the output torque of the motor 42 should be increased, and to decrease the auxiliary torque provided to the user, the output torque of the motor 42 should be decreased. The auxiliary torque command value is obtained based on various information obtained from a detection unit that includes an acceleration sensor 33 and detects the tilt angle of the user's upper body.

[0079] The following section will describe a specific example of the process for obtaining the command value of the auxiliary torque used to reduce the action. Figure 8 This is a block diagram illustrating a portion of the deceleration process performed by the processing unit 16, and Figure 9 This is a flowchart illustrating an example of the process. Figure 8 The process for obtaining the auxiliary torque command value τa is shown. When "reduction action" is selected in operation unit 14 ( Figure 9 Step St50) involves performing a lowering motion. The user's lowering motion includes not only the action of the user holding the load with their hands and leaning their upper body forward to lower the load, but also the action of the user leaning their upper body forward without holding the load with their hands (bending over).

[0080] The lowering motion processing is the process of providing assistive torque to the user when the user wearing the assistive device 10 performs a lowering motion. Furthermore, when the user performs a lowering motion, as described above, the assistive torque generated by the assistive device 10 is a torque in the direction that changes the user's posture from a forward-leaning posture to an upright posture, that is, a torque in the lifting direction. When the user performs a lowering motion, the assistive device 10 generates assistive torque as an assistive force to slow down the user's forward leaning of his or her upper body. Regarding the positive and negative signs of the assistive torque, as... Figure 4 As shown, the lifting direction and the lowering direction are defined as negative and positive, respectively.

[0081] The entire descent motion process will be described (see [link]). Figure 9The process of acquiring the tilt angle θh obtained by the triaxial accelerometer 33 is performed (step St60). The calculation unit 16a performs various calculations based on the information about the tilt angle θh (step St70), and obtains the auxiliary torque command value τa based on the result of the processing (step St80). A command signal for causing the drive units 13R and 13L to output an auxiliary torque corresponding to the command value τa is provided to the motor driver 18 (step St90). The motor driver 18 activates the drive units 13R and 13L based on the command signal (step St100). Therefore, auxiliary torque is provided to the user. Figure 9 The loop shown is—that is Figure 9 The series of processes shown are repeated at predetermined intervals (e.g., a series of processes are performed every 0.001 seconds) until the lowering action is completed (step St110). The lowering action process for the right drive unit 13R is the same as the lowering action process for the left drive unit 13L and is performed simultaneously.

[0082] Will use Figure 8 A specific example of the processing to obtain the command value τa is described. Based on the detection signal from the triaxial accelerometer 33, the calculation unit 16a obtains the user's tilt angle θh. Figure 8 The frame B50 and Figure 9 Step St60). The tilt angle θh is stored in storage device 17.

[0083] Using the acquired tilt angle θh, the calculation unit 16a obtains the time-based change θv (rate of change of time) of the tilt angle θh. Figure 8 The frame B60 and Figure 9 Step St70). As described above, since the descent action processing is repeatedly executed at a predetermined period, the calculation unit 16a can use the tilt angle θh(t-1) obtained in the previous (directly preceding) descent action processing, the tilt angle θh(t) obtained in the current descent action processing, and the value t of the predetermined period to obtain the time-based change θv of the tilt angle θh according to the following formula: θv=(θh(t)-θh(t-1)) / t.

[0084] The time-based change θv of the tilt angle θh is stored in the storage device 17. The time-based change θv of the tilt angle θh can be referred to as the movement speed of the upper body when tilting and the angular velocity of the upper body when tilting. In the following text, the time-based change θv of the tilt angle θh can be referred to as "angular velocity θv".

[0085] In the control device 15, a virtual spring constant K is set as the stiffness term gain and a damping constant d is set as the viscosity term gain. Information regarding the corresponding values ​​of the virtual spring constant K and the damping constant d is stored in the storage device 17. The corresponding values ​​of the virtual spring constant K and the damping constant d are preset values, and for example, as... Figure 10 As shown, each of these constants is set to a different value for each intensity level (level 1, 2, or 3) of the auxiliary operation used for reduction.

[0086] As will be understood from the description below, the damping constant d is a constant used to reduce the auxiliary torque command value τa when reducing movement; that is, a constant used to reduce the mitigating effect on the user's forward leaning of his or her upper body. Therefore, the damping constant d can also be called the auxiliary reduction constant (auxiliary reduction term).

[0087] The value of each of the virtual spring constant K and damping constant d is selected based on the intensity setting of the auxiliary operation (level 1, 2, or 3). The intensity of the auxiliary operation is set by the user via the operation unit 14 (selection button) at the start of the action. When "High (Level 3)" is selected in setting the intensity of the auxiliary operation, the value of the virtual spring constant K is chosen to be larger than that when "Low (Level 1 or Level 2)" is selected. Although levels 1, 2, and 3 are shown as settings for the intensity of the auxiliary operation, more levels (e.g., levels 0, 1, 2, 3, 4, etc.) can be provided.

[0088] The calculation unit 16a multiplies the obtained tilt angle θh by the virtual spring constant K. Figure 8 Box B51 and Figure 9 Step St70). The process of performing this multiplication is the first process. In this embodiment, the virtual spring constant K has a negative sign at levels 2 and 3. As described above, the lifting direction is defined as negative for the auxiliary torque. Therefore, in the first process, the auxiliary torque command value in the negative direction increases with the increase of the tilt angle θh. Therefore, the first process for increasing the auxiliary force as the tilt angle θh increases is performed.

[0089] As a process separate from the first process, the calculation unit 16a multiplies the obtained upper body angular velocity θv by the damping constant d( Figure 8 Box B61 and Figure 9Step St70). The process of performing this multiplication is the second process. In this embodiment, the damping constant d has a positive sign at levels 2 and 3. As mentioned above, the lifting direction is defined as negative with respect to the auxiliary torque. Therefore, in the second process, the auxiliary torque command value in the negative direction decreases as the tilt angle θh increases. Therefore, a second process is performed to reduce the auxiliary force as the angular velocity θv of the upper body increases. This second process can be referred to as the "auxiliary weakening process" for reducing the auxiliary force.

[0090] The calculation unit 16a obtains an auxiliary torque command value as an auxiliary parameter for reducing the movement based on the results of the first and second processing. Specifically, the calculation unit 16a obtains the sum of the value obtained by multiplying the tilt angle θh by the virtual spring constant K and the value obtained by multiplying the angular velocity θv by the damping constant d. Figure 8 Box B70 and steps Figure 9 The sum of these values ​​is set as the auxiliary torque command value τa used to reduce the motion (St70), and the sum is set as the value of the auxiliary torque command τa used to reduce the motion. Figure 9 Step St80).

[0091] Figure 11 This is a graph showing the auxiliary torque command value τa obtained by the processing unit 16 (calculation unit 16a). Figure 11 In the graph, the vertical and horizontal axes represent the auxiliary torque and the upper body angular velocity θv, respectively, when the movement is reduced. Figure 11 In the diagram, a tilt angle θh of 30 degrees is indicated by a dashed line, and a tilt angle θh of 60 degrees is indicated by a solid line. Regarding the positive and negative signs of the auxiliary torque, the direction of lifting is negative, and the direction of lowering is positive. For example... Figure 11 As shown, regardless of the tilt angle θh, the auxiliary torque command value τa approaches zero as the upper body angular velocity θv increases. In other words, as the angular velocity θv increases, the mitigating effect on the user's forward tilting of his or her upper body decreases.

[0092] As already described, when a user leans forward, the processing unit 16 of the control device 15 obtains an auxiliary torque command value based on the user's upper body tilt angle θh and upper body angular velocity θv. This auxiliary torque command value is used to provide an auxiliary force to the user in the direction that brings the user to an upright posture. In this embodiment, the processing unit 16 may perform an auxiliary weakening process (second processing) to reduce the auxiliary force (command value τa) as the angular velocity θv increases.

[0093] The assistive device 10 with the above-described structure uses the tilt angle θh of the user's upper body to obtain the assist torque command value τa. Therefore, compared to a small tilt angle θh, when the upper body is tilted forward to a large extent and the tilt angle θh is large, the assistive device 10 can generate a larger assist force. Thus, for example, the burden on the user's hip BW can be reduced more effectively. Furthermore, the assist torque command value τa is obtained not only using the tilt angle θh of the user's upper body but also using the angular velocity θv, which is a time-based change in the tilt angle. In particular, processing is performed to reduce the assist force when the angular velocity θv increases. Therefore, in the case where the user tilts his or her upper body forward to a relatively large extent, temporarily stops the action, and then tilts his or her upper body forward further, the assist force can be reduced according to the angular velocity θv when the upper body begins to move, and thus the user can easily take a posture of further forward tilting.

[0094] Figure 12 This is a diagram illustrating a modified example of the second processing. Figure 12 The graph shown illustrates the value obtained by multiplying the angular velocity θv by the damping constant d, and the angular velocity θv, respectively, on the vertical and horizontal axes. Since the processing unit 16 obtains the angular velocity θv at predetermined intervals, it can determine whether the angular velocity θv is increasing or decreasing at the current time point (in the current processing). That is, when the user leans forward, the processing unit 16 can determine whether the action involves acceleration or deceleration.

[0095] Even with the same angular velocity θv, the damping constant d in the case of acceleration and the damping constant d in the case of deceleration are set to different values. For example, by Figure 12 As indicated by arrows J1 and J2 shown in Figure 12, when the user's forward leaning motion involves acceleration, processing unit 16 increases the rate of reduction in assist force. Conversely, as indicated by arrows J3 and J4 shown in Figure 12, when the user's forward leaning motion involves deceleration, processing unit 16 decreases the rate of reduction in assist force. Therefore, the damping constant d is a variable value, and the value of the damping constant d used in acceleration is different from the value of the damping constant d used in deceleration. Therefore, processing unit 16 performs the following process as a second process: obtaining the acceleration or deceleration of the user's forward leaning motion, and making the rate of reduction in assist force greater when acceleration is obtained than the rate of reduction in assist force when deceleration is obtained.

[0096] In this modified example, when the leaning motion involves acceleration, such as when the user quickly lowers a relatively light load, the ratio of the assist force in the direction leading the user to an upright posture increases, and therefore, the user can more easily perform the leaning motion. Conversely, when the leaning motion involves deceleration, such as when the user slowly lowers a heavy load, the ratio of the assist force in the direction leading the user to an upright posture decreases, and therefore, appropriate assist force can be provided to the user. When the user performs an action involving acceleration, such as when the user begins to lower a relatively heavy load, the ratio of the assist force in the direction leading the user to an upright posture increases, and therefore, the user can more easily perform the leaning motion. Furthermore, when the user performs an action to lower the load and is about to stop the action near the target position (i.e., when the leaning motion decelerates), the ratio of the assist force in the direction leading the user to an upright posture decreases, and therefore, appropriate assist force can be provided to the user.

[0097] Second type of auxiliary device 10

[0098] Figure 13 This is a perspective view showing the second type of assistive device 10. The assistive device 10 includes a first wearable unit 11 worn on the user's upper body, a right second wearable unit 12R worn on the user's right thigh, a left second wearable unit 12L worn on the user's left thigh, and an actuator 9. Figure 1 The auxiliary device 10 (first form) shown and Figure 13 The components with the same function in the auxiliary device 10 shown are indicated by the same reference numerals.

[0099] In the second form, the actuator 9 includes a power unit 79B corresponding to the backpack 24 in the first form, and a right drive unit 13R positioned on the right side of the user's hip and a left drive unit 13L positioned on the left side. Each of the power unit 79B and the right drive unit 13R and left drive unit 13L is coupled together via a frame 23 made of metal or the like. A first-body wearable unit 11 is mounted on the power unit 79B and the right drive unit 13R and left drive unit 13L.

[0100] The power unit 79B includes a motor 83 inside the housing 84, and a right drive pulley 81R and a left drive pulley 81L driven by the motor 83 to rotate. A triaxial accelerometer 33 is disposed inside the power unit 79B as a detection unit for detecting the tilt angle of the user's upper body. The left drive unit 13L has a driven pulley 80L disposed inside the housing 36. The right drive unit 13R has a driven pulley 80R disposed inside the housing 36. Each of the right driven pulley 80R and the left driven pulley 80L is disposed inside the housing 36 to be able to rotate around an imaginary line Li in one direction and another direction, which passes through the user in the left and right directions at a position near his or her hip. On the left side, a wire 82L is wound around the drive pulley 81L and the driven pulley 80L, and on the right side, a wire 82R is wound around the drive pulley 81R and the driven pulley 80R. The wires 82R and 82L are respectively housed in the conduit 77 located between the power unit 79B and the right housing 36 and the left housing 36.

[0101] When the right drive pulley 81R and the left drive pulley 81L rotate in one direction via the motor 83, the right driven pulley 80R and the left driven pulley 80L rotate in the same direction, with wires 82R and 82L serving as power transmission components. When the drive pulleys 81R and 81L rotate in the other direction via the motor 83, the driven pulleys 80R and 80L rotate in the other direction, with wires 82R and 82L serving as power transmission components. Arms 37 are respectively mounted on the driven pulleys 80R and 80L, and each of the driven pulleys 80R and 80L moves integrally with the arm 37. Second wearable units 12R and 12L are mounted at the lower part of the arm 37.

[0102] The torque of the right arm 37 and left arm 37, which swing around the imaginary line Li due to the rotation of the driven pulleys 80R and 80L, is provided to the user as an auxiliary torque. Each of the right drive unit 13R and the left drive unit 13L can operate independently of each other and perform different operations, or they can perform the same operation simultaneously. Therefore, the actuator 9 can perform auxiliary operations that provide auxiliary force to the user through the first wearable unit 11 and the second wearable units 12R and 12L.

[0103] Similarly, in the second embodiment, the auxiliary device 10 includes a sensor 53 that obtains the swing angle of the arm 37, representing the angle formed by the user's upper body and thighs. The sensor 53 is used to detect the rotation angle of the driven pulleys 80R and 80L, which move integrally with the arm 37, and is, for example, an encoder or an angle sensor. The sensor 53 has the same function as the second detector 52 in the first embodiment. Since the rotation angle of the driven pulley 80L (80R) and the rotation angle of the drive pulley 81L (81R) are related to each other, a sensor that detects the swing angle of the arm 37 based on the rotation angle of the drive pulley 81L (81R) can be used as a detector to obtain the swing angle of the arm 37.

[0104] Similarly, in the second embodiment, as in the first embodiment, the auxiliary device 10 includes a control device 15 that performs the lowering action. Control device 15 (see...) Figure 7 This includes: a processing unit (processing device) 16 including a central processing unit (CPU); a storage device 17 formed by non-volatile memory and the like, storing information such as various programs and databases; and a motor driver 18 for controlling the motor 83. In the first embodiment, the processing unit 16 detects the tilt angle θh of the user's upper body and obtains the time-based change θv (angular velocity θv) of the tilt angle θh of the user's upper body by calculating the tilt angle θh. Figure 8 As shown.

[0105] As in the first form (see Figure 8 In this process, processing unit 16 performs a first process to increase the assist force as the tilt angle θh of the user's upper body increases. Furthermore, processing unit 16 performs a second process to decrease the assist force as the time-based change θv (angular velocity θv) of the tilt angle θh increases (becomes higher). Processing unit 16 obtains an assist torque command value τa as an assist parameter based on the results of the first and second processes. Motor 83 operates with an output corresponding to the command value τa. Specific examples of these processes are as follows... Figures 8 to 12 The example of the processing shown is the same, and therefore its description will be omitted here.

[0106] Like the assistive device 10 in the first form, the assistive device 10 in the second form performs the assistive operation using arm 37 by operating the right drive unit 13R and the left drive unit 13L. This assistive operation is achieved by providing the user with an assistive torque around an imaginary line Li via the first wearable unit 11 and the second wearable units 12R, 12L. The imaginary line Li passes through the user in the left-right direction at a position near his or her hip BW. The second form is identical to the first form in this respect.

[0107] The auxiliary torque command value τa obtained by the processing unit 16 is the value of the torque that causes the arm 37 to swing around the imaginary line Li. This torque is generated by the motor 83 of the actuator 9. Therefore, the torque output by the drive units 13R and 13L using the torque of the motor 83 is the "auxiliary torque" provided by the auxiliary device 10.

[0108] Similarly, in the second form, the processing unit 16 can be configured to perform the following process as a second process: obtain the acceleration or deceleration of the user's forward leaning motion, and make the rate of reduction of the assistive force greater when acceleration is obtained than the rate of reduction of the assistive force when deceleration is obtained, such as... Figure 12 As described.

[0109] As already described, Figure 1 The auxiliary device 10 (first form) shown and Figure 13 The actuator 9 of each of the auxiliary devices 10 (second form) shown is configured as follows. The actuator 9 includes a right drive unit 13R mounted on the first wearable unit 11 to the right side of the user's hip BW and a left drive unit 13L to the left side, as well as a right arm 37 and a left arm 37. The front ends of the right arm 37 and the left arm 37 are respectively mounted on second wearable units 12R and 12L, which are worn on the user's thigh BF, and the base ends of the right arm 37 and the left arm 37 are respectively mounted on the drive units 13R and 13L. Each of the right arm 37 and the left arm 37 swings back and forth about its base end.

[0110] The actuator 9 is configured to provide the user with an auxiliary force (auxiliary torque) in the opposite direction to the forward leaning direction by generating torque around its base on each of the right and left arms 37 when the user changes the posture of his or her upper body in the forward leaning direction. For example, when the user lowers the load, i.e., when the user places a load held in his or her hands on the floor or the like, the user changes his or her posture from an upright posture to a forward leaning posture. The auxiliary device 10 with this configuration can generate an auxiliary force in the direction that brings the upper body from the forward leaning posture to an upright posture. Therefore, the auxiliary device can generate such an auxiliary force as to slow down the user's forward leaning of his or her upper body.

[0111] Modification examples of the first and second processing methods

[0112] As described above, in addition to the triaxial accelerometer 33 installed in the power unit 79B (backpack 24), the auxiliary device 10 of the second form (first form) includes a sensor 53 (second detector 52) installed on the drive units 13R and 13L as a device for detecting the tilt angle of the upper body. The accelerometer 33 detects the tilt angle relative to the vertical line V (see...). Figure 4The sensor 53 (second detector 52) detects the tilt angle θh of the user's upper body relative to the user's thigh BF. Since the tilt angle θh(θL) is based on real-time detection, the processing unit 16 can obtain the time-based change θv (angular velocity θv) of the tilt angle θh(θL) of the user's upper body based on the tilt angle θh(θL).

[0113] like Figure 14 As shown, the tilt angle θh used in the first process can be a value obtained by the triaxial accelerometer 33, and the angular velocity θv used in the second process can be a value obtained by the sensor 53 (second detector 52). Figure 14 It is shown Figure 8 The diagram shows a modified example of the processing. Therefore, when the user performs a forward leaning motion, the processing unit 16 can obtain an auxiliary torque command value τa based on the tilt angle θh obtained by the triaxial accelerometer 33 and the angular velocity θv obtained by the sensor 53 (second detector 52), to provide an auxiliary force to the user in the direction that brings the user to an upright posture.

[0114] Third type of auxiliary device 10

[0115] Figure 15 This is a perspective view showing the third form (in the state of being worn by the user) of the assistive device 10. The assistive device 10 includes: a first wearable unit 11 worn on the user's upper body; a right second wearable unit 12R worn on the user's right leg and a left second wearable unit 12L worn on the user's left leg; an actuator 9 that provides assistive force to the user through the first wearable unit 11 and the second wearable units 12R and 12L; and a triaxial accelerometer 33 as a detection unit for detecting the tilt angle of the user's upper body. In this respect, this assistive device 10 is the same as that according to the first form of the assistive device 10. Figure 15 In the third form shown, the second body wearing units 12R and 12L are worn on the knee of the leg.

[0116] The first wearable unit 11 is made of flexible fabric or the like. The first wearable unit 11 includes a back body 61 worn on the user's back, and shoulder straps 62 and hip straps 63 connected to the back body 61. The back body 61 is worn on the user's back. The lengths of the shoulder straps 62 and hip straps 63 are adjustable, and these lengths are adjusted to ensure close contact between the back body 61 and the user's back. The first wearable unit 11 is worn in a way that prevents movement relative to the user's upper body in the forward / backward, right / left, and up / down directions.

[0117] The right second-body wearable unit 12R and the left second-body wearable unit 12L are mirror images of each other, but these units have the same configuration. Each of the right second-body wearable unit 12R and the left second-body wearable unit 12L is made of flexible fabric or the like. Each of the second-body wearable units 12R and 12L includes a knee body 64 worn on the back of the user's knee BN, and a knee strap 65 extending from the knee body 64. The knee strap 65 surrounds the knee BN and is secured to the knee body 64 by contact and closing fasteners (hook fasteners) or the like. The fixed position of the knee strap 65 is adjusted so that the second-body wearable units 12R and 12L are in close contact with the knee BN. Each of the second-body wearable units 12R and 12L is worn in a way that prevents movement relative to the knee BN in the front-back, right-left, and up-down directions.

[0118] Actuator 9 includes a strap 70 and a winding unit 71. The strap 70 is configured to extend along the rear side of the user to connect the first wearable unit 11 to each of the second wearable units 12R, 12L. The winding unit 71 can wind and unwind (i.e., unwind) a portion of the strap 70. The strap 70 includes a first strap portion 70a corresponding to the upper body side of the user, a second strap portion 70b corresponding to the lower body side of the user, and a coupling member 72 coupling the first strap portion 70a and the second strap portion 70b together. Each of the first strap portion 70a and the second strap portion 70b is elongated and flexible.

[0119] The winding unit 71 is disposed inside the backpack 24, which is mounted on the first wearable unit 11 (back body 61). Figure 16 This is a view showing the winding unit 71. The winding unit 71 includes a motor 73 and a roller 74 that can be rotated by the motor 73 and winds the belt 70. When the winding unit 71 winds the belt 70, tension is applied to the belt 70. This tension provides assistive force to the user in the task and reduces the physical burden on the user. For example, when a user changes his or her posture from a forward-leaning position to an upright position while supporting the load with his or her hands (gripping the load), the winding unit 71 winds the belt 70 to apply tension to the belt 70. This tension helps the user change his or her posture from a forward-leaning position to an upright position and reduces the physical burden on the user.

[0120] When the user changes his or her posture from an upright position to a forward-leaning position, i.e., when the user performs a lowering action, the winding unit 71 operates to wind the belt 70 off the roller 74 while generating torque in the direction that winds the belt 70 onto the roller 74. As the user lowers, the winding unit 71 generates an assistive force that slows the user's forward leaning motion. This assistive force is based on the tension on the belt 70 that the roller 74 is attempting to wind, and it reduces the strain on the user's body during the lowering action. When the user stops leaning, the posture is maintained by the tension on the belt 70 to further reduce the strain on the user's body. The actuator 9, which includes the belt 70 and the winding unit 71, as already described, can perform an assistive operation that provides the assistive force to the user via the first body-wearing unit 11 and the second body-wearing units 12R, 12L.

[0121] As in the first form, the auxiliary device 10 according to the third form includes a control device 15 that performs the lowering action processing. Control device 15 (see...) Figure 7 This includes: a processing unit (processing device) 16 including a central processing unit (CPU); a storage device 17 formed by non-volatile memory and the like, storing information such as various programs and databases; and a motor driver 18 for controlling the motor 73. In the first embodiment, the processing unit 16 detects the tilt angle θh of the user's upper body and obtains the time-based change θv (angular velocity θv) of the user's upper body tilt angle θh based on the detected tilt angle θh. Figure 8 As shown.

[0122] As in the first form (see Figure 8 In this process, processing unit 16 performs a first process to increase the assist force as the tilt angle θh of the user's upper body increases. Furthermore, processing unit 16 performs a second process to decrease the assist force as the time-based change θv (angular velocity θv) of the tilt angle θh increases. Based on the results of the first and second processes, processing unit 16 obtains an assist torque command value τa as an assist parameter. Motor 73 operates with an output corresponding to the command value τa. Specific examples of these processes are as follows... Figures 8 to 12 The example of the processing shown is the same, and therefore its description will be omitted here.

[0123] The third type of auxiliary device 10 performs an auxiliary operation by winding the belt 70 through the winding unit 71 when the user performs a lifting action and when the user performs a lowering action. This auxiliary operation is the operation of providing tension to the belt 70 to the user through the first body-wearing unit 11 and the second body-wearing units 12R, 12L when the winding unit 71 winds the belt 70.

[0124] The auxiliary torque command value τa obtained by the processing unit 16 is the torque value of the winding unit 71 (roller 74) winding the tape 70. This torque is generated by the motor 73 of the winding unit 71. Therefore, the torque output by the winding unit 71 using the torque of the motor 73 is the "auxiliary torque" provided by the auxiliary device 10.

[0125] Similarly, in the third form, the processing unit 16 can be configured to perform the following processing as a second processing: obtaining the acceleration or deceleration of the user's forward leaning motion, and making the rate of reduction of the assistive force greater when acceleration is obtained than the rate of reduction of the assistive force when deceleration is obtained, such as... Figure 12 As described.

[0126] As already described, Figure 15 and Figure 16 The actuator 9 of the auxiliary device 10 (third form) shown is configured as follows. The actuator 9 includes a winding unit 71 and a belt 70. The winding unit 71 includes a roller 74 and a motor 73 that rotates the roller 74, and the winding unit 71 is mounted on the first wearable unit 11. The belt 70 has a first end wound around the roller 74 and a second end mounted on the second wearable units 12R, 12L. The motor 73 generates torque in the direction in which the roller 74 winds a portion of the belt 70.

[0127] For example, when a user lowers the load, i.e., when the user places a load held in their hands on the floor or similar surface, the user changes their posture from an upright position to a forward-leaning position. The assistive device 10 with this configuration can generate an assistive force in the direction that brings the upper body from the forward-leaning position back to an upright position. In other words, the assistive device can generate such an assistive force that slows down the user's forward-leaning movement of their upper body.

[0128] Various types of auxiliary devices 10

[0129] In the various first, second, and third types of auxiliary devices 10, the control device 15 obtains an auxiliary torque command value τa for causing the actuator 9 to generate a desired auxiliary force, and executes control to cause the actuator 9 to operate with an output corresponding to the command value τa. When the user leans forward, the control device 15 obtains the command value τa based on the user's upper body tilt angle θh and the time-based change θv of the tilt angle θh, to provide the user with an auxiliary force in the direction that brings the user to an upright posture. Furthermore, as the time-based change θv increases, the control device 15 can perform an auxiliary force reduction process to decrease the auxiliary force.

[0130] These assistive devices 10 in various forms use the tilt angle θh of the user's upper body to obtain the assist torque command value τa. When the upper body is tilted forward to a large extent and the tilt angle θh is large, the assistive device 10 generates a large assist force. Therefore, for example, the burden on the user's hips can be reduced more effectively. Furthermore, the assist torque command value τa is obtained not only using the tilt angle θh of the user's upper body, but also using the time-based change θv (angular velocity θv) of the tilt angle θh. In particular, when the time-based change θv of the tilt angle θh increases, a process for reducing the assist force is performed. Therefore, in the case where the user tilts his or her upper body forward to a relatively large extent, temporarily stops the movement, and then tilts his or her upper body forward further, when the upper body begins to move, the assist force can be reduced according to the time-based change θv of the tilt angle θh, and thus the user can easily take a further forward tilting posture.

[0131] In the first, second, and third types of assistive devices 10, for example, when the user performs a load-reducing action, the assistive force increases with the tilt angle θh of the upper body. When the user stops in a forward-leaning posture at a predetermined tilt angle θh, the time-based change θv of the tilt angle θh becomes zero, and this forward-leaning posture is maintained by a relatively large assistive force, thus reducing the burden on the user. When the user begins a further forward-leaning action and the time-based change θv of the tilt angle θh increases, an assistive torque command value τa is obtained in the direction of decreasing assistive force. Therefore, the user can easily adopt a forward-leaning posture.

[0132] As already described, when the user leans forward, the assistive device 10 of each of the above forms can increase the assistive force as the user's upper body tilt angle θh increases, and allow the user to move easily when performing a further forward tilt from that state. Furthermore, when the user performs the forward tilting action relatively quickly and the time-based change θv of the tilt angle θh increases, the control device 15 obtains an assist torque command value τa in the direction of decreasing the assistive force. Therefore, the user can easily assume a forward tilting posture.

[0133] The mechanisms of each part of the auxiliary device 10 in each of the above forms can have configurations different from those shown in the accompanying drawings. For example, the first wearable unit 11 can have a different form than that shown in the accompanying drawings, as long as it is configured to be worn on the user's upper body. The second wearable units 12R and 12L can have different forms than those shown in the accompanying drawings, as long as they are configured to be worn on the user's right and left legs. Figure 1 and Figure 13In the form shown, the configuration of actuator 9 can also be different, as long as it includes an arm 37 that provides auxiliary torque to the user by swinging back and forth. Figure 15 In the form shown, the configuration of actuator 9 can be different, as long as it is configured to wind the tape body 70.

[0134] In the above-described form, the detection unit for detecting the tilt angle (θh) of the upper body has been described as a triaxial accelerometer 33. However, the detection unit can be any other sensor configured to generate an output that varies according to the user's upper body posture. In the above-described form, the processing unit 16 obtains an auxiliary parameter for assisting operation as a torque value (auxiliary torque). However, the auxiliary parameter can be a parameter other than the torque value, and can be, for example, a load (force).

[0135] The embodiments disclosed above are illustrative in all respects and not restrictive. The scope of the invention is not limited to the above embodiments, but includes all modifications within the range equivalent to the configurations described in the claims.

Claims

1. An auxiliary device, characterized in that, include: The first wearable unit (11) is worn on the user's upper body; Left and right second-body wearable units (12L, 12R) are worn on the user's left and right legs; An actuator (9) is configured to provide assistive force to the user via the first wearable unit (11) and the second wearable unit (12L, 12R); The detection unit is configured to detect the tilt angle of the user's upper body; as well as A controller is configured to: obtain auxiliary parameters for causing the actuator (9) to generate a desired auxiliary force, and execute control for causing the actuator (9) to operate with an output corresponding to the auxiliary parameters, wherein: When the user performs a forward leaning motion, the controller obtains auxiliary parameters based on the tilt angle and its time-based change to provide the user with an auxiliary force in the direction that enables the user to achieve an upright posture; and The controller is configured to further perform auxiliary attenuation processing to reduce the auxiliary force as the time-based change in the tilt angle increases. The controller is configured to: execute a first process to increase the auxiliary force when the tilt angle increases, execute a second process as an auxiliary force reduction process to decrease the auxiliary force when the time-based change of the tilt angle increases, and obtain the auxiliary parameters based on the results of the first and second processes. The controller is configured to further perform the following process as the second process: obtain the acceleration or deceleration of the user's forward leaning motion, and reduce the assist force by a greater rate when the acceleration is obtained than by a greater rate when the deceleration is obtained.

2. The auxiliary device according to claim 1, characterized in that: The actuator (9) includes: Drive units (13L, 13R), which are mounted on the first wearable unit (11) to be located on the left and right sides of the user's hip, and Arms (37), each of the arms (37) having a front end mounted on a corresponding one of the second body-wearing units (12L, 12R) on the thigh of the user's leg, and a base end mounted on a corresponding one of the drive units (13L, 13R), each of the arms (37) being configured to swing back and forth about the base end; and The actuator (9) is configured to provide an auxiliary force to the user in the opposite direction to the forward tilt direction by generating a torque on the arm (37) around the base end when the user changes the posture of the upper body in the forward tilt direction.

3. The auxiliary device according to claim 1, characterized in that: The actuator (9) includes: A winding unit (71), comprising a roller (74) and a motor for rotating the roller (74), the winding unit (71) being mounted on the first wearable unit (11), and The belt (70) has a first end wound around the roller (74) and a second end mounted on the second body wearing unit (12L, 12R); The actuator (9) is configured to generate torque via the motor in the direction in which the roller (74) winds a portion of the belt (70); and The actuator (9) is configured to, when the user changes the posture of the upper body in the forward leaning direction, simultaneously generate torque in the direction that winds the belt (70) onto the roller (74) and unwind the belt (70).

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