Walking auxiliary force level acquisition method applied to exoskeleton device and exoskeleton device

Abstract

The invention belongs to the technical field of exoskeleton robots, and provides a walking auxiliary force level obtaining method applied to an exoskeleton device and the exoskeleton device. S100, acquiring a reference walking track according to the walking track of the normal person; s200, acquiring a detected walking track from the walking track of the patient in the unpowered state; s300, calculating an amplitude deviation value and a horizontal deviation value; and step S400, acquiring the walking auxiliary force level required by normal walking of the patient. According to the exoskeleton device, when a wearer of the exoskeleton device walks by using lower limb muscles, the exoskeleton device provides walking auxiliary force, and a patient wearing the exoskeleton device can well perform lower limb rehabilitation under the help of the exoskeleton device, so that the technical problems existing in the prior art are effectively avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of exoskeleton robots, and in particular, relates to a method for acquiring a walking assist force level applied to an exoskeleton device and an exoskeleton device. Background Art

[0002] In order to program the walking drive of the exoskeleton device and analyze the walking pattern of a normal person, known methods for analyzing gait include motion capture, force plate and inverse dynamics. The motion capture method uses a camera to track markers attached to the body and obtains a three-dimensional modeling of the walking movement based on the tracking data changes. In addition, the force plate method measures the pressure applied to the ground during walking and tracks the walking trajectory based on the measured data. In addition, the inverse dynamics method is the motion cap, which has a combined form of formula and force plate method to calculate the pure torque value of each joint.

[0003] Walking can be completed through the stance phase and the angular phase. The stance phase refers to the time when the foot contacts the ground, while the angular phase refers to the time when the foot leaves the ground, which is the time when the foot moves forward. For patients with lower limb motor dysfunction, the angular phase of the lower limb moving forward during walking is a more complex process than the stance phase of landing on the ground.

[0004] In the prior art, the exoskeleton device is driven by a pre-stored and programmed driving force, regardless of the walking force of the user (wearer). Generally, the lower limb movement ability of the user of the exoskeleton device is lower than that of a normal person. If the driving force of the exoskeleton device is the same as that of a normal person, the user (wearer) will no longer use the lower limb muscles to walk, which may delay the user's (wearer's) recovery. Summary of the invention

[0005] The purpose of the present invention is to provide a method for obtaining a walking assist force level applied to an exoskeleton device, so as to solve the technical problems existing in the prior art.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A method for obtaining a walking assist force level applied to an exoskeleton device comprises the following steps; Step S100: obtaining a reference walking trajectory according to a normal person's walking trajectory; Step S200: acquiring a detected walking trajectory from the walking trajectory of the patient in a non-powered state; Step S300: Calculate the amplitude deviation value and the horizontal deviation value; Step S400: Obtain the walking assistance force level required for the patient to walk normally.

[0007] In one embodiment, the reference walking trajectory is obtained from the walking trajectory of a normal person and includes a reference walking trajectory α * and a reference walking trajectory peak α * ma .

[0008] In one embodiment, the detected walking trajectory is obtained by having a patient wear an exoskeleton device in a powerless state and walk a predetermined distance, and includes a detected walking trajectory α and a detected walking trajectory peak α max .

[0009] In one embodiment, the specific calculation method of step S300 is as follows; First, calculate the difference between the reference walking trajectory peak α * max and the detected walking trajectory peak α max , that is, the amplitude deviation value Δα max , and the calculation formula is as follows: Δα max =α * max -α max Then, calculate the horizontal deviation value according to the amplitude deviation value, and the calculation formula is as follows: ΔA = K·Δα max where K represents a change coefficient, which is a set value, and those skilled in the art can set it according to the actual situation.

[0010] In one embodiment, the specific method of step S400 is as follows: When |Δαmax| ≤ αt, then A = A′ When at (|Δαmax| > αt) and (0 < A′ + ΔA ≤ 1), then A = A′ + ΔA When (|Δαmax| > αt) and (A′ + ΔA ≤ 0, or, A′ + ΔA > 1), A = 1 where αt refers to the allowable deviation range of the reference walking trajectory, and A′ + ΔA is the sum of the previous level and the horizontal deviation value, which refers to the stage change range.

[0011] To achieve the above object, the present invention also provides an exoskeleton device, including an exoskeleton device main body and a controller. The exoskeleton device main body includes a first driving part for driving a user's thigh and a second driving part for driving a user's calf; The controller includes: a memory module storing a reference walking trajectory; The walking assistance force level acquisition module acquires the detection walking trajectory from the patient's walking trajectory in the unpowered state, and calculates the amplitude deviation value and the horizontal deviation value according to the reference walking trajectory and the detection walking trajectory to acquire the walking assistance force level required for the patient to walk normally; The walking driving module drives the first driving unit and the second driving unit according to the walking assist force level.

[0012] In one embodiment, the first driving part and the second driving part each include: a fixed body and a rotating body, wherein the rotating body can rotate relative to the fixed body via a crank; In one embodiment, the fixed body comprises a cover frame having an axial hole, a motor mounted on the cover frame and generating a rotational force, and a ball screw mounted on the cover frame and having a fastener; In one embodiment, the rotating body includes a crank connected to the axial hole and having a connecting piece, and a rotating body frame connected to the crank; one end of the connecting rod is connected to the fastener of the ball screw, and the other end is connected to the connecting piece of the crank.

[0013] In one embodiment, an angle sensor for detecting a rotation angle of the crank is arranged on the cover frame.

[0014] In one embodiment, the exoskeleton device body includes a main body mounted on the back of the user, a pelvic support portion mounted on the lower part of the main body, a thigh support portion connected to the lower part of the pelvic support portion, a calf support portion connected to the bottom of the thigh support portion, and a foot support portion connected to the bottom of the calf support portion.

[0015] In one embodiment, the pelvic support portion includes a pelvic support member and the first driving portion, wherein the first driving portion is arranged at the lower part of the pelvic support member and connected to the thigh support portion; the thigh support portion includes a thigh support member and the second driving portion, wherein the second driving portion is arranged at the lower part of the thigh support member and connected to the calf support portion.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The method for acquiring the level of walking assist force applied to an exoskeleton device provided by the present invention is used to analyze the walking pattern of a wearer of the exoskeleton device, can detect the walking force of the wearer of the exoskeleton device, and acquire the walking assist force required for walking. While the wearer of the exoskeleton device uses the lower limb muscles to walk, the exoskeleton device provides walking assist force. Patients wearing the exoskeleton device can better perform lower limb rehabilitation with the help of the exoskeleton device, thereby effectively avoiding the technical problems existing in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a front view of the exoskeleton device.

[0018] Figure 2 A side view of the exoskeleton device.

[0019] Figure 3 It is a schematic diagram of the structure of the driving part in the present invention.

[0020] Figure 4 Graphs showing the baseline walking trajectory and the detected walking trajectory during the angular period.

[0021] Figure 5 It is a flowchart of the method for obtaining the walking assist force level in the present invention.

[0022] The names corresponding to the reference numerals are as follows: 1-main body, 2-pelvic support part, 3-thigh support part, 4-calf support part, 5-foot support part, 6-crank, 7-controller, 8-battery, 9-upper shoulder strap, 10-axis line; 101-cover frame, 102-motor, 103-ball screw, 104-fastener; 201-connecting rod, 202-rotating body frame, 203-connecting piece; 21- pelvic support member, 22- first driving part; 31-thigh support, 32-second drive unit, 33-thigh belt; 41 - calf support, 42 - calf strap. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to have a clearer understanding and knowledge of the present invention, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described below are only used to explain the present invention, and are convenient for understanding. The technical solutions provided by the present invention are not limited to the technical solutions provided by the following embodiments, and the technical solutions provided by the embodiments should not limit the protection scope of the present invention.

[0024] Unless otherwise defined, the technical terms or scientific terms used in the disclosure of this application shall have the usual meanings understood by persons with ordinary skills in the field to which the disclosure belongs. The words "include" or "comprise" and the like used in this application mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. The positional relationship words "upper", "lower", "left", "right", "front", "back", etc. are determined according to the layout direction of the drawings in the specification, and are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0025] Example like Figures 1 to 5 As shown, this embodiment provides a method for obtaining a walking assist force level applied to an exoskeleton device, which is used to detect the walking force of a user wearing the exoskeleton device, to analyze the walking pattern of the user using the exoskeleton device, and to apply the analyzed data to the driving of the exoskeleton device to assist the user's insufficient walking force.

[0026] The exoskeleton device referred to in this embodiment includes a main body installed on the user's back, a pelvic support part installed at the lower part of the main body, a thigh support part connected to the lower part of the pelvic support part, a calf support part connected to the bottom of the thigh support part, and a foot support part connected to the bottom of the calf support part.

[0027] The controller and the battery may be configured inside the main body and located on the rear side of the main body, and an upper shoulder strap for connecting the upper body of the user (wearer) is installed on the front side of the main body, and the upper shoulder strap may be composed of a shoulder strap and a waist belt.

[0028] The pelvic support part is installed on the lower two sides of the main body, and the pelvic support part is installed at a predetermined angle on the side of the body. The pelvic support part consists of a pelvic support member and a first driving part; the first driving part is arranged at the lower part of the pelvic support member, and makes the thigh support part converge according to the control signal of the controller.

[0029] The thigh support part is composed of a thigh support, a second driving part and a thigh belt, wherein the thigh support is connected to the first driving part, the second driving part is arranged at the lower part of the thigh support, and the calf support part is converged according to the control signal of the controller, and the thigh belt is installed on the thigh support and fixes the user's thigh.

[0030] The calf support part is composed of a calf support and a calf belt, the calf belt is installed on the calf support and connected to the user's foot support, and the calf support is connected to the second driving part; the foot support part is composed of a foot support and a foot belt, which is installed on the foot support and binds the user's foot.

[0031] In the above, the structures of the main body, battery, upper shoulder strap, pelvic support, thigh support, calf support and foot support can all adopt existing mature structures. This embodiment mainly improves the controller and drive part.

[0032] In this embodiment, the controller includes a memory module, a walking driving module and a walking assist force level acquisition module. The walking driving module drives the first driving unit of the pelvic support unit and the second driving unit of the thigh support unit; the walking assist force level acquisition module detects the maximum walking angle from the user's test walking trajectory, and acquires the walking assist force level required for normal walking on this basis.

[0033] The first driving part and the second driving part mentioned above have the same structure, both of which include a fixed body and a rotating body. Further, the fixed body and the rotating body are axially connected, and the rotating body is rotated from the fixed body through a crank.

[0034] The fixing part is composed of a cover frame with an axial hole, a motor installed on the cover frame and generating a rotating force, and a ball screw installed on the cover frame and having a fastener; the rotating body is composed of a crank connected to the axial hole and having a connecting piece, and a rotating body frame connected to the crank. The connecting rod is connected to the fastener of the ball screw and the connecting ball of the crank.

[0035] Through the above arrangement, the ball screw converts rotational motion into linear motion. When the motor rotates according to the control signal of the controller, the rotational force of the motor is transmitted to the ball screw. The crank connected by the fastener of the ball screw and the connecting ball of the tapered rod pushes or pulls the tapered rod, so that the rotating frame connected to the connecting rod can rotate around the axis.

[0036] In this embodiment, based on the first driving unit, the fixed body is installed at the lower part of the pelvic support, and the rotating body is installed at the upper part of the thigh support; based on the second driving unit, the fixed body is installed at the lower part of the thigh support, and the rotating body is installed at the upper part of the calf support.

[0037] Meanwhile, an angle sensor (not shown) is mounted on the cover frame of the fixed body. The angle sensor detects the rotation angle of the crank, which is output to the walking assist force level acquisition module of the controller.

[0038] In this embodiment, the walking assist force level acquisition module can acquire the walking assist force level applied to the exoskeleton device driving part (first driving part, second driving part), that is, the level of the walking assist force; the walking assist force level refers to the driving force obtained by subtracting the driving force of the patient (exoskeleton device wearer) when walking from the driving force corresponding to the walking of a normal person, that is, the driving force of the patient (exoskeleton device wearer) plus the driving force of the exoskeleton device driving part can achieve normal walking.

[0039] The walking assistance force level acquisition module detects the patient's driving force, and on this basis obtains the walking assistance force level required for the patient's normal walking. The level of walking assistance force can be represented by multiple increasing numbers, for example, it can be classified into level 1 to level 10.

[0040] In this embodiment, the method for obtaining the walking assist force level applied to the exoskeleton device is as follows: Step S100: obtaining a reference walking trajectory according to a normal person's walking trajectory; Step S200: acquiring a detected walking trajectory from the walking trajectory of the patient in a non-powered state; Step S300: Calculate the amplitude deviation value and the horizontal deviation value; Step S400: Obtain the walking assistance force level required for the patient to walk normally.

[0041] like Figure 4 As shown, a graph of the reference walking trajectory and the detected walking trajectory is shown, showing the reference walking trajectory (α * ) and detected walking trajectory (α). The reference walking trajectory is pre-stored data (stored in the controller) obtained from the walking trajectory of a normal person; the detected walking trajectory is detected by the angle sensor installed in the driving part (first driving part, second driving part) of the exoskeleton device when the patient is in an unpowered state, and the driving force is applied to the driving part of the exoskeleton device in the unpowered state.

[0042] The following is a detailed description and explanation of each step: 1. Obtain a baseline walking trajectory based on a normal person's walking trajectory.

[0043] In this embodiment, the reference walking trajectory is obtained from the walking trajectory of a normal person, which is a known data, including the reference walking trajectory α* and the reference walking trajectory peak α * max Based on the peak value, a 5% allowable deviation range αt is set. It should be noted that the allowable deviation range αt can be set between 3% and 7%. The reference walking trajectory thus obtained is stored in a memory module of the controller.

[0044] Second, obtain the detected walking trajectory from the patient's walking trajectory in an unpowered state.

[0045] In this embodiment, the walking trajectory detected can be obtained by the patient wearing the exoskeleton device in a non-powered state and repeatedly walking a predetermined distance. The walking trajectory detected by the angle sensor installed in the driving part (first driving part, second driving part) of the exoskeleton device includes detecting the walking trajectory α and detecting the walking trajectory peak α max .

[0046] 3. Calculate the amplitude deviation value and the horizontal deviation value.

[0047] First, calculate the peak value α of the baseline walking trajectory * max And detect the walking trajectory peak α max The difference between the amplitude deviation and the amplitude deviation is Δα. max , the calculation formula is as follows: Δα max =α * max -α max Then, the horizontal deviation value is calculated according to the amplitude deviation value, and the calculation formula is as follows: ΔA = K·Δα max Wherein, K represents a change coefficient, which is a set value, and those skilled in the art can set it according to the actual situation.

[0048] IV. Obtain the walking assistance force level required for the patient to walk normally.

[0049] Obtaining the walking assistance force level required for the patient to walk normally can be considered as a change in the walking assistance force level A. The change in the walking assistance force level A includes maintaining the previous level A' and changing the previous level A'. Whether the level changes is determined by the following formula, as shown below: When |Δαmax| ≤ αt, then A = A' When αt (|Δαmax| > αt) and (0 < A'+ ΔA ≤ 1), then A = A'+ ΔA When (|Δαmax| > αt) and (A'+ ΔA ≤ 0, or, A'+ ΔA > 1), A = 1 Wherein, αt refers to the allowable deviation range of the reference walking trajectory, and A'+ ΔA is the sum of the previous level and the level deviation value, which refers to the stage change range.

[0050] Wherein, αt refers to the allowable deviation range of the reference walking trajectory, and A'+ ΔA is the sum of the previous level and the level deviation value.

[0051] When the amplitude deviation value Δα max is equal to or less than the allowable deviation range αt, the level (level) of the walking assistance force remains unchanged, that is, the previous preset level is maintained. The preset level refers to the level set according to the lower limb movement state of the patient. For example, it can be the level set by the administrator according to experience.

[0052] If the amplitude deviation value Δα max is greater than the allowable deviation range αt and within the stage change range, then adjust the level of the walking assistance force; if the amplitude deviation value Δα max is greater than the allowable deviation range αt and equal to or exceeds the boundary value of the stage change range, for safety reasons, forcefully adjust to the lowest level of the walking assistance force.

[0053] Through the above, the level of the walking assistance force changed in this way is transmitted to the walking drive module of the controller, and the exoskeleton device is driven with the driving force of the current walking assistance force level. The user wearing the exoskeleton device has insufficient lower limb muscle strength and can walk normally like a normal person with the driving force of the exoskeleton device.

[0054] The lower limb motor ability of the user wearing the exoskeleton device is lower than that of a normal person. If the driving force of the exoskeleton device is the same as that of a normal person, the user will no longer use the lower limb muscles, so the user's rehabilitation may be delayed. According to the technical solution provided in this embodiment, the driving part of the exoskeleton device can provide the auxiliary force that the user lacks, and the patient wearing the exoskeleton device can smoothly perform lower limb rehabilitation with the help of the exoskeleton device.

[0055] The above is the preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements without departing from the design principle and technical solution of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A method for obtaining a walking assist force level applied to an exoskeleton device, characterized in that: The steps include: Step S100: obtaining a reference walking trajectory according to a normal person's walking trajectory; Step S200: acquiring a detected walking trajectory from the walking trajectory of the patient in a non-powered state; Step S300: Calculate the amplitude deviation value and the horizontal deviation value; Step S400: Obtain the walking assistance force level required for the patient to walk normally.

2. The method for obtaining the walking assist force level applied to an exoskeleton device according to claim 1, characterized in that: The reference walking trajectory is obtained from the walking trajectory of a normal person, and includes the reference walking trajectory α * and the peak value α of the baseline walking trajectory * ma .

3. The method for obtaining the walking assist force level applied to an exoskeleton device according to claim 2, characterized in that: The walking trajectory detection is obtained by the patient wearing the exoskeleton device in a non-powered state and walking a predetermined distance, which includes detecting the walking trajectory α and detecting the walking trajectory peak α max .

4. The method for obtaining the walking assist force level applied to an exoskeleton device according to claim 3, characterized in that: The specific calculation method of step S300 is as follows; First, calculate the peak value α of the baseline walking trajectory * max And detect the walking trajectory peak α max The difference between the amplitude deviation and the amplitude deviation is Δα. max , the calculation formula is as follows: Da max =a * max -a max Then, the horizontal deviation value is calculated according to the amplitude deviation value, and the calculation formula is as follows: ΔA=K·Dα max Wherein, K represents the coefficient of variation, which is a set value and can be set by those skilled in the art according to actual conditions.

5. The method for obtaining the walking assist force level applied to an exoskeleton device according to claim 4, characterized in that: The specific method of step S400 is as follows: When |Δαmax|≤αt, then A = A′ When at (|Δαmax| > αt) and (0 < A'+ ΔA ≤ 1), then A = A'+ ΔA When (|Δαmax| > αt) and (A'+ ΔA ≤ 0, or, A'+ ΔA > 1), A = 1 Among them, αt refers to the allowable deviation range of the benchmark walking trajectory, A'+ΔA is the sum of the previous level and level deviation values, and refers to the stage change range.

6. An exoskeleton device, comprising an exoskeleton device body and a controller, characterized in that: The exoskeleton device body comprises a first driving unit (22) for driving a user's thigh and a second driving unit (32) for driving a user's calf; The controller comprises: A memory module storing a reference walking trajectory; The walking assistance force level acquisition module acquires the detection walking trajectory from the patient's walking trajectory in the unpowered state, and calculates the amplitude deviation value and the horizontal deviation value according to the reference walking trajectory and the detection walking trajectory to acquire the walking assistance force level required for the patient to walk normally; A walking drive module drives the first drive unit (22) and the second drive unit (32) according to the walking assist force level.

7. The exoskeleton device according to claim 6, characterized in that: The first driving part (22) and the second driving part (32) both comprise: a fixed body (10) and a rotating body (20), wherein the rotating body (20) is rotatable relative to the fixed body (10) via a connecting rod (6); The fixed body (10) comprises a cover frame (101) having an axial hole, a motor (102) mounted on the cover frame (101) and generating a rotational force, and a ball screw (103) mounted on the cover frame (101) and having a fastener (104); The rotating body (20) comprises a crank (201) connected to the shaft hole and having a connecting piece (203), and a rotating body frame (202) connected to the crank (201); one end of the connecting rod (6) is connected to the fastener (104) of the ball screw (103), and the other end is connected to the connecting piece (203) of the crank (201).

8. The exoskeleton device according to claim 7, characterized in that: An angle sensor for detecting the rotation angle of the crank (201) is arranged on the cover frame (11).

9. The exoskeleton device according to claim 8, characterized in that: The exoskeleton device body comprises a main body (1) mounted on the back of a user, a pelvic support part (2) mounted at the lower part of the main body (1), a thigh support part (3) connected to the lower part of the pelvic support part (2), a calf support part (4) connected to the bottom of the thigh support part (3), and a foot support part (5) connected to the bottom of the calf support part (4).

10. The exoskeleton device according to claim 9, characterized in that: The pelvic support portion (2) comprises a pelvic support member (21) and the first drive portion (22), wherein the first drive portion (22) is arranged at the lower part of the pelvic support member (21) and connected to the thigh support portion (3); the thigh support portion (3) comprises a thigh support member (31) and the second drive portion (32), wherein the second drive portion (32) is arranged at the lower part of the thigh support member (31) and connected to the calf support portion (4).

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