Gait Detection System and Detection Method Based on Foot Exoskeletons

Abstract

The present invention relates to the technical field of exoskeleton gait recognition, and particularly to a gait detection system and method based on a foot exoskeleton, including: a foot exoskeleton for wearing on a user's foot, the foot exoskeleton including a foot main body, a front foot sole plate, and a rear foot sole plate, the front foot sole plate including a first connection end and a second connection end, the first connection end of the front foot sole plate being connected to the foot main body, and the second connection end being connected to the rear foot sole plate. In this application, by collecting the distance and the change in distance between the front foot main body and the rear foot sole plate, the rotation angle of the ankle and the change in the angle, and the Euler angle of the Y-axis of the calf and the change in the Euler angle of the Y-axis, the collected data has high reliability, small calculation amount, and can accurately judge the postures of the leg and the foot to identify the postures of the current user's foot and leg.

Description

Technical Field

[0001] The present invention relates to the technical field of exoskeleton gait recognition, and particularly to a gait detection system and method based on a foot exoskeleton. Background Art

[0002] Exoskeleton gait recognition methods mainly rely on a variety of sensors and algorithms to accurately capture and analyze human gait characteristics. For example, sensor-based gait recognition, and the sensor-based recognition method is usually an IMU (Inertial Measurement Unit) sensor or a pressure sensor; the IMU sensor collects human gait data, and uses components such as an accelerometer and a gyroscope in the IMU sensor to measure the motion state of the human body in real time, including angular velocity, acceleration, etc. However, obtaining dynamic data of the foot exoskeleton through the IMU sensor has problems of large computational complexity and high cost. The pressure sensor can identify different stages of gait, such as the stance phase, swing phase, etc. by measuring the pressure distribution and changes on the sole of the foot. The pressure sensor has a small computational amount, but the recognition accuracy of gait is not high, and it cannot reflect different gaits of the foot exoskeleton.

[0003] Therefore, how to accurately recognize gait at low cost is an urgent problem to be solved. Summary of the Invention

[0004] In view of the technical problems existing in the foot exoskeleton gait recognition in the prior art, the first aspect of the present invention proposes a gait detection system based on a foot exoskeleton, including:

[0005] A foot exoskeleton for wearing on a user's foot, the foot exoskeleton includes a foot main body, a forefoot sole plate and a hindfoot sole plate, the forefoot sole plate includes a first connection end and a second connection end, the first connection end of the forefoot sole plate is connected to the foot main body, the second connection end is connected to the hindfoot sole plate, and the foot main body and the hindfoot sole plate are elastically connected;

[0006] A calf exoskeleton connected to the foot main body and capable of rotating relative to the foot main body;

[0007] A first detection unit connected to the bottom of the foot main body for detecting the distance between the foot main body and the hindfoot sole plate;

[0008] A second detection unit connected at the pivot joint of the foot main body and the calf exoskeleton for detecting the rotation angle of the foot main body relative to the calf exoskeleton. It is defined that the state where the foot main body is perpendicular to the calf exoskeleton is the initial state, the plantar flexion movement of the foot is the positive rotation, and the dorsiflexion movement of the foot is the reverse rotation;

[0009] The third detection unit, connected to the calf exoskeleton, is configured to detect the Euler angle of the calf exoskeleton on the Y-axis. When the calf exoskeleton is collinear with the body length direction, it is defined as the initial position. When the calf exoskeleton is in front of the body, it is a reverse rotation, and when the calf exoskeleton is behind the body, it is a forward rotation;

[0010] The controller is electrically connected to the first detection unit, the second detection unit, and the third detection unit;

[0011] Wherein, the controller obtains the distance h between the foot main body and the rear foot sole plate and the change rate Kh of the distance according to the first detection unit, the controller obtains the rotation angle w of the foot main body relative to the calf exoskeleton and the change rate Kw of the rotation angle according to the second detection unit, and the controller obtains the Euler angle Ry of the calf exoskeleton on the Y-axis and the change rate KRy of the Euler angle according to the third detection unit;

[0012] The controller determines the current posture of the foot exoskeleton according to multiple parameters among h, Kh, w, Kw, Ry, and KRy.

[0013] Preferably, the controller determines the force state of the rear foot sole plate according to the distance h between the foot main body and the rear foot sole plate and the change rate Kh of the distance.

[0014] Preferably, when standing statically, the distance between the foot main body and the rear foot sole plate is defined as hl; the postures of the foot exoskeleton include the first posture, the second posture, the third posture, and the fourth posture in the walking posture;

[0015] The first posture is the heel of the foot exoskeleton touching the ground;

[0016] The second posture is the forefoot of the foot exoskeleton touching the ground, and the relative angle w between the foot exoskeleton and the calf exoskeleton is defined as w ∈ [w1, w2], and the Euler angle Ry of the calf exoskeleton on the Y-axis is Ry ∈ [Ry1, Ry2];

[0017] The third posture is the heel of the foot exoskeleton leaving the ground;

[0018] The fourth posture is the forefoot of the foot exoskeleton leaving the ground;

[0019] When Kh < 0, Kw > 0, KRy(t - 1) < 0 ∩ KRy(t) > 0, the controller determines that the foot exoskeleton is in the first posture;

[0020] When h < hl, Kh > 0, Kw < 0, w ∈ [w1, w2], Ry ∈ [Ry1, Ry2], the controller determines that the foot exoskeleton is in the second posture;

[0021] When h > hl, w > 0, Kw > 0, and KRy > 0, the controller determines that the foot exoskeleton is in the third posture;

[0022] When h > hl, Kh > 0, Kw ≈ 0, and KRy(t - 1) > 0 ∩ KRy(t) < 0, the controller determines that the foot exoskeleton is in the fourth posture.

[0023] Preferably, an elastic element is provided between the foot main body and the rear foot sole plate, and a connecting plate is also provided between the foot main body and the rear foot sole plate. The elastic element, the rear foot sole plate, and the connecting plate form a triangular structure, and the length of the side where the elastic element is located is variable.

[0024] Preferably, the front foot sole plate is configured as a flexible structure, and the distance between the first connection end and the second connection end of the front foot sole plate is variable.

[0025] Preferably, the first detection unit includes a Hall sensor module, and the Hall sensor module includes a Hall sensor provided at the bottom of the foot main body and a permanent magnet provided at the upper part of the rear foot sole plate; the second detection unit includes an angle sensor, and the third detection unit includes an attitude sensor.

[0026] Preferably, the first detection unit corresponds to the heel of the foot main body.

[0027] In a second aspect of the present invention, a technical solution is proposed. A gait detection method based on a foot exoskeleton uses the above-mentioned gait detection system based on a foot exoskeleton, and includes the following steps:

[0028] Step 1: Real-time detect the distance h between the foot main body and the rear foot sole plate and the change rate Kh of the distance, the rotation angle w of the foot main body relative to the calf exoskeleton and the change rate Kw of the rotation angle, the Euler angle Ry of the calf exoskeleton on the Y axis and the change rate KRy of the Euler angle;

[0029] Step 2: Determine the current posture of the foot exoskeleton according to multiple parameters among h, Kh, w, Kw, Ry, and KRy.

[0030] Preferably, the postures of the foot exoskeleton include the first posture, the second posture, the third posture, and the fourth posture in the walking posture;

[0031] When Kh < 0, Kw > 0, and KRy(t - 1) < 0 ∩ KRy(t) > 0, it is determined that the foot exoskeleton is in the first posture;

[0032] When h < hl, Kh > 0, Kw < 0, w ∈ [w1, w2], and Ry ∈ [Ry1, Ry2], it is determined that the foot exoskeleton is in the second posture;

[0033] When h > hl, w > 0, Kw > 0, and KRy > 0, the controller determines that the foot exoskeleton is in the third posture;

[0034] When h > hl, Kh > 0, Kw ≈ 0, KRy(t - 1) > 0 ∩ KRy(t) < 0, the controller determines that the foot exoskeleton is in the fourth posture.

[0035] Compared with the prior art, the advantages of the present invention are as follows:

[0036] In this application, the foot exoskeleton is set to include a foot main body, a front foot main body, and a rear foot bottom plate. A certain distance is formed between the front foot main body and the rear foot bottom plate. When the user walks, the distance between the front foot main body and the rear foot bottom plate changes periodically. By analyzing the distance between the front foot main body and the rear foot bottom plate and its change, the rotation angle of the ankle and its change, the Euler angle of the Y-axis of the calf and its change, the collected data has high reliability and small calculation amount, and can accurately judge the postures of the leg and the foot to identify the postures of the current user's foot and leg. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in each figure may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the present invention will be described by way of example and with reference to the drawings, wherein:

[0038] Figure 1 is a schematic structural diagram of a gait detection system based on a foot exoskeleton shown in the present invention;

[0039] Figure 2 is a schematic structural diagram of the foot exoskeleton shown in the present invention;

[0040] FIG. 3(a) is a schematic diagram of a simplified model of the foot exoskeleton shown in the present invention in the first posture;

[0041] FIG. 3(b) is a schematic diagram of a simplified model of the foot exoskeleton shown in the present invention in the second posture;

[0042] FIG. 3(c) is a schematic diagram of a simplified model of the foot exoskeleton shown in the present invention in the third posture;

[0043] FIG. 3(d) is a schematic diagram of a simplified model of the foot exoskeleton shown in the present invention in the fourth posture;

[0044] Figure 4 is a schematic diagram of the rotation direction of the calf exoskeleton and the change of the Euler angle of the Y-axis of the foot exoskeleton shown in the present invention in different postures. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] To better understand the technical content of the present invention, specific embodiments are hereby given and described in conjunction with the accompanying drawings as follows.

[0046]

Gait Detection System Based on Foot Exoskeleton

[0047] Combined with Figure 1 As shown in the figure, a first aspect of the present invention provides a gait detection system based on a foot exoskeleton, including a foot exoskeleton 10, a calf exoskeleton 20, a first detection unit 16, a second detection unit 21, a third detection unit 22, and a controller. The foot exoskeleton 10 and the calf exoskeleton 20 are worn on the patient's foot and leg, and the gait of the foot is judged by detecting the motion states of the foot exoskeleton 10 and the calf exoskeleton 20.

[0048] As Figure 2 shown, the foot exoskeleton 10 includes a foot main body 11, a forefoot sole plate 12, and a rear foot sole plate 13. The forefoot sole plate 12 includes a first connection end and a second connection end. The first connection end of the forefoot sole plate 12 is connected to the foot main body 11, and the second connection end is connected to the rear foot sole plate 13. The foot main body 11 and the rear foot sole plate 13 are elastically connected.

[0049] Compared with the current integrated foot exoskeleton, the bottom of the foot exoskeleton 10 in this application is divided into three modules: the foot main body 11, the forefoot sole plate 12, and the rear foot sole plate 13. The foot main body 11 and the rear foot sole plate 13 are elastically connected. When the foot steps on the ground, the distance between the foot main body 11 and the rear foot sole plate 13 changes. The forefoot sole plate 12 is hinged to the foot main body 11 and the rear foot sole plate 13, with a large degree of flexibility, and makes the actions of the user's heel touching the ground and the forefoot touching the ground clearer and easier to judge.

[0050] The calf exoskeleton 20 is connected to the foot main body 11 and can rotate relative to the foot main body 11. Thus, the gait of the user can be further judged through the relative attitude characteristics between the calf exoskeleton 20 and the foot exoskeleton 10.

[0051] Furthermore, the first detection unit 16 is connected to the bottom of the foot main body 11 for detecting the distance between the foot main body 11 and the rear foot sole plate 13.

[0052] When the distance between the foot main body 11 and the rear foot sole plate 13 decreases, it indicates that the load borne by the foot main body 11 relative to the ground increases, that is, the user's foot is in the process of touching the ground and falling. When the distance between the foot main body 11 and the rear foot sole plate 13 increases, then the heel of the user has a tendency to lift off the ground.

[0053] Therefore, the controller judges the force state of the rear foot sole plate 13 according to the distance h between the foot main body 11 and the rear foot sole plate 13 and the rate of change of the distance Kh.

[0054] Further, the second detection unit 21 is connected to the pivot joint of the foot main body 11 and the calf exoskeleton 20 for detecting the rotation angle of the foot main body 11 relative to the calf exoskeleton 20. It is defined that the perpendicular state of the foot main body 11 and the calf exoskeleton 20 is the initial state, the plantar flexion movement of the foot is the positive rotation, and the dorsiflexion movement of the foot is the reverse rotation.

[0055] It can be understood that when the foot performs plantar flexion movement, the data detected by the second detection unit 21 gradually increases. When the foot performs dorsiflexion movement, the data detected by the second detection unit 21 gradually decreases. When the foot main body 11 and the calf exoskeleton 20 are in the vertical state, the data detected by the second detection unit 21 is 0, that is, the initial position. At this time, when performing plantar flexion movement, the data detected by the second detection unit 21 is a positive number. If dorsiflexion movement is performed at this time, the data detected by the second detection unit 21 is a negative number.

[0056] Therefore, the controller can judge the angle of the ankle according to the rotation angle w, and judge the change trend of the ankle through the slope of the rotation angle w.

[0057] Further, the third detection unit 22 is connected to the calf exoskeleton 20 for detecting the Euler angle of the calf exoskeleton 20 on the Y axis. It is defined that when the calf exoskeleton 20 is collinear with the body length direction is the initial position, when the calf exoskeleton 20 is in front of the body is the reverse rotation, and when the calf exoskeleton 20 is behind the body is the positive rotation.

[0058] It can be understood that when the calf is in the forward extension state, the Euler angle of the Y axis detected by the third detection unit 22 gradually increases. When the calf is in the backward extension state, the Euler angle of the Y axis detected by the third detection unit 22 gradually decreases. When the calf is parallel to the human body, that is, in the state perpendicular to the ground, the Euler angle of the Y axis of the calf at this time is zero. At this time, if the calf moves forward, the Euler angle of the Y axis is a negative number. If the calf moves backward, the Euler angle of the Y axis is a positive number.

[0059] In this way, the controller can judge the posture of the calf according to the Euler angle of the Y axis, that is, whether it is in front of or behind the body. It should be understood that during the movement of the user, the two legs are in interactive movement, that is, a single leg forms a certain periodic movement. The controller can also judge which area of the current movement cycle the calf is in according to the slope of the Euler angle of the Y axis.

[0060] The controller is electrically connected to the first detection unit 16, the second detection unit 21, and the third detection unit 22, and is used for receiving the data detected by the detection unit, and calculating and comparing and judging the slope of the data.

[0061] Among them, the controller obtains the distance h and the change rate Kh of the distance between the foot main body 11 and the rear foot sole plate 13 in the current state according to the first detection unit 16. The controller obtains the rotation angle w and the change rate Kw of the rotation angle of the foot main body 11 relative to the calf exoskeleton 20 in the current state according to the second detection unit. The controller obtains the Euler angle Ry of the calf exoskeleton 20 on the Y-axis and the change rate KRy of the Euler angle in the current state according to the third detection unit 22.

[0062] It should be understood that the foot exoskeleton 10 has multiple postures. If the multiple postures are to be distinguished, the characteristics of each posture need to be accurately judged. The controller judges the current posture of the foot exoskeleton 10 according to multiple parameters among h (the distance between the foot main body 11 and the rear foot sole plate 13), Kh (the change rate of the distance between the foot main body 11 and the rear foot sole plate 13), w (the rotation angle of the foot main body 11 relative to the calf exoskeleton 20), Kw (the change rate of the rotation angle of the foot main body 11 relative to the calf exoskeleton 20), Ry (the Euler angle of the calf exoskeleton 20 on the Y-axis), and KRy (the change rate of the Euler angle of the calf exoskeleton 20 on the Y-axis).

[0063] The above parameters can characterize the force state and force change of the foot at the current moment, the angle state and angle change of the ankle, the Y-axis position of the leg, and the change of the position. Through these parameters, the posture of the foot can be accurately judged. Moreover, the parameters obtained by the above sensors are all obtained when the detected object makes a clear movement, and the detection accuracy is high.

[0064] In an alternative embodiment, when static standing is defined, the distance between the foot main body 11 and the rear foot sole plate 13 is hl; the postures of the foot exoskeleton 10 include a first posture, a second posture, a third posture, and a fourth posture in the walking posture.

[0065] The first posture is that the heel of the foot exoskeleton 10 touches the ground.

[0066] The second posture is that the forefoot of the foot exoskeleton 10 touches the ground, and the relative angle w between the foot exoskeleton 10 and the calf exoskeleton 20 is defined as w ∈ [w1, w2], and the Euler angle Ry of the calf exoskeleton 20 on the Y-axis is Ry ∈ [Ry1, Ry2].

[0067] It should be understood that in the walking posture, when the forefoot touches the ground, the posture of the human body is in a relatively determined position, that is, the relative angle w between the foot exoskeleton 10 and the calf exoskeleton 20 is within a preset range, for example, w ∈ [w1, w2]. Similarly, the Euler angle of the calf exoskeleton 20 on the Y-axis is also within a preset range, for example, Ry ∈ [Ry1, Ry2]. This can be used as one of the judgment criteria for the forefoot to touch the ground.

[0068] The third posture is that the heel of the foot exoskeleton 10 leaves the ground.

[0069] The fourth posture is that the forefoot of the foot exoskeleton 10 leaves the ground.

[0070] In an optional embodiment, the judgment criteria for the above first posture, second posture, third posture, and fourth posture are as follows:

[0071] When Kh < 0, Kw > 0, KRy(t - 1) < 0 ∩ KRy(t) > 0, the controller determines that the foot exoskeleton 10 is in the first posture;

[0072] When h < hl, Kh > 0, Kw < 0, w ∈ [w1, w2], Ry ∈ [Ry1, Ry2], the controller determines that the foot exoskeleton 10 is in the second posture;

[0073] When h > hl, w > 0, Kw > 0, KRy > 0, the controller determines that the foot exoskeleton 10 is in the third posture;

[0074] When h > hl, Kh > 0, Kw ≈ 0, KRy(t - 1) > 0 ∩ KRy(t) < 0, the controller determines that the foot exoskeleton 10 is in the fourth posture.

[0075] Combined with Fig. 3(a) and Figure 4 As shown, when Kh < 0, the change amount of the distance between the foot main body 11 and the rear foot sole plate 13 is less than zero, the heel is in a compressed state. When Kw > 0, the ankle is in a state of rotating forward. When KRy(t - 1) < 0 ∩ KRy(t) > 0, it indicates that the Euler angle of the calf exoskeleton 20 on the Y-axis is at the trough position, that is, it has moved forward to the limit position. At this time, it can be judged that the heel touches the ground.

[0076] Combined with Fig. 3(b) and Figure 4 As shown, when h < hl, it indicates that the compression amount of the heel is less than the normal standing state. When Kh > 0, it indicates that the change amount is greater than zero, and the heel is in a state of rebounding. When Kw < 0, it indicates that the ankle rotates in the reverse direction, that is, it is in a dorsiflexion movement. When w ∈ [w1, w2], Ry ∈ [Ry1, Ry2], it indicates that the ankle angle and the Euler angle of the calf on the Y-axis are within the preset range of the forefoot touchdown posture, and it can be judged that the forefoot is in a state of touching the ground at this time.

[0077] Combined with Fig. 3(c) and Figure 4 As shown, when h > hl, it indicates that the compression amount of the heel is greater than the normal tension state, the pressure on the heel is less than the pressure during standing, the heel is off the ground, w > 0 indicates that the ankle flips downward, Kw > 0 indicates that the ankle is in a plantar flexion movement, and when KRy > 0, it indicates that the calf exoskeleton 20 is behind the body, which can represent the state of the heel leaving the ground at this time.

[0078] Combined with Fig. 3(d) and Figure 4As shown, when h > hl, it indicates that the compression amount at the heel is greater than the normal tension state, the pressure on the heel is less than the pressure during standing, the heel is off the ground, Kh > 0, which indicates that the change amount of the distance between the foot main body 11 and the rear foot sole plate 13 is greater than zero, and the heel is in a released state. Kw ≈ 0, which indicates that the ankle angle basically does not change. KRy(t - 1) > 0 ∩ KRyt < 0, which indicates that the Euler angle of the calf exoskeleton 20 on the Y-axis is at the peak position, that is, it has stepped backward to the limit. At this time, it can be judged that the forefoot leaves the ground.

[0079] In an alternative embodiment, an elastic element 15 is provided between the foot main body 11 and the rear foot sole plate 13, and a connecting plate 14 is also provided between the foot main body 11 and the rear foot sole plate 13. The elastic element 15, the rear foot sole plate 13 and the connecting plate 14 form a triangular structure, and the length of the side where the elastic element 15 is located is variable.

[0080] Through this structure, a stable sandwich structure is formed between the foot main body 11 and the rear foot sole plate 13, and they only approach each other when compressed, converting the change in force into the change in the distance between the foot main body 11 and the rear foot sole plate 13, and at the same time providing buffering for the user.

[0081] Furthermore, the forefoot sole plate 12 is configured as a flexible structure, and the distance between the first connection end and the second connection end of the forefoot sole plate 12 is variable. In this way, the forefoot and the heel of the foot are separated. When the user's forefoot touches the ground and the heel touches the ground, the foot can deform adaptively, and it is reflected in the spatial change between the foot main body 11 and the rear foot sole plate 13, which is beneficial for feature recognition.

[0082] In an alternative embodiment, the first detection unit 16 includes a Hall sensor module, and the Hall sensor module includes a Hall sensor provided at the bottom of the foot main body 11 and a permanent magnet provided at the upper part of the rear foot sole plate 13; the second detection unit 21 includes an angle sensor, and the third detection unit 22 includes an attitude sensor.

[0083] It can be seen that only the third detection unit 22 uses an attitude sensor and only detects the Euler angle on the Y-axis. The sensors used in the other two places have low cost and small amount of detected data. Therefore, high-precision attitude recognition with low cost and low computational complexity is achieved.

[0084] Furthermore, the first detection unit 16 corresponds to the heel of the foot main body 11.

[0085] Optionally, the first detection unit 16 includes two pairs of Hall sensor modules arranged along the length direction of the rear foot plate 13. In this way, the inclination state between the foot main body 11 and the rear foot plate 13 can be judged by the difference in the detection results of the two groups of Hall sensor modules. For example, the first Hall sensor module is arranged on the front side of the hinge point of the connecting plate 14, and the second Hall sensor module is arranged on the rear side of the hinge point of the connecting plate 14. When the heel touches the ground, the distance h1 detected by the second Hall sensor module is less than the distance h2 detected by the first Hall sensor module, and when the forefoot touches the ground, the distance h1 detected by the second Hall sensor module is greater than the distance h2 detected by the first Hall sensor module. Therefore, only the two groups of Hall sensor modules can also be used as auxiliary conditions to judge the posture of the foot.

[0086]

Gait Detection Method Based on Foot Exoskeleton

[0087] In a second aspect of the present invention, a technical solution is proposed, a gait detection method based on a foot exoskeleton, using the above-mentioned gait detection system based on a foot exoskeleton, including the following steps:

[0088] Step 1, detect the distance h between the foot main body 11 and the rear foot plate 13 and the change rate Kh of the distance in real time, the rotation angle w of the foot main body 11 relative to the calf exoskeleton 20 and the change rate Kw of the rotation angle, and the Euler angle Ry of the calf exoskeleton 20 on the Y axis and the change rate KRy of the Euler angle;

[0089] Step 2, judge the current posture of the foot exoskeleton 10 according to multiple parameters among h, Kh, w, Kw, Ry and KRy.

[0090] Optionally, the postures of the foot exoskeleton 10 include the first posture, the second posture, the third posture and the fourth posture in the walking posture;

[0091] When Kh < 0, Kw > 0, KRyt-1 < 0 ∩ KRyt > 0, it is judged that the foot exoskeleton 10 is in the first posture;

[0092] When h < hl, Kh > 0, Kw < 0, Kh < 0, w ∈ [w1, w2], Ry ∈ [Ry1, Ry2], it is judged that the foot exoskeleton 10 is in the second posture;

[0093] When h > hl, w > 0, Kw > 0, KRy > 0, the controller judges that the foot exoskeleton 10 is in the third posture;

[0094] When h > hl, Kh > 0, Kw ≈ 0, KRyt-1 > 0 ∩ KRyt < 0, the controller judges that the foot exoskeleton 10 is in the fourth posture.

[0095] In the specific judgment method:

[0096] Combined with Fig. 3(a) and Figure 4 as shown, when Kh < 0, the change amount of the distance between the foot main body 11 and the rear foot sole plate 13 is less than zero, and the heel is in a compressed state. When Kw > 0, the ankle is in a state of rotating forward. When KRy(t - 1) < 0 ∩ KRy(t) > 0, it indicates that the Euler angle of the calf exoskeleton 20 on the Y-axis is at the trough position, that is, it has stepped forward to the limit position. At this time, it can be judged that the heel touches the ground.

[0097] Combined with Fig. 3(b) and Figure 4 as shown, when h < hl, it indicates that the compression amount of the heel is less than the normal standing state. When Kh > 0, it indicates that the change amount is greater than zero, and the heel is in a state of rebounding. When Kw < 0, it indicates that the ankle rotates in the reverse direction, that is, it is in a dorsiflexion movement. When w ∈ [w1, w2] and Ry ∈ [Ry1, Ry2], it indicates that the ankle angle and the Euler angle of the calf on the Y-axis are within the preset range of the forefoot landing posture, and it can be judged that the foot is in the state of forefoot landing at this time.

[0098] Combined with Fig. 3(c) and Figure 4 as shown, when h > hl, it indicates that the compression amount of the heel is greater than the normal tension state, the pressure on the heel is less than the pressure when standing, the heel is off the ground, w > 0 indicates that the ankle flips downward, and Kw > 0 indicates that the ankle is in a plantar flexion movement. When KRy > 0, it indicates that the calf exoskeleton 20 is behind the body, which can represent the state of heel lift at this time.

[0099] Combined with Fig. 3(d) and Figure 4 as shown, when h > hl, it indicates that the compression amount of the heel is greater than the normal tension state, the pressure on the heel is less than the pressure when standing, the heel is off the ground, Kh > 0 indicates that the change amount of the distance between the foot main body 11 and the rear foot sole plate 13 is greater than zero, and the heel is in a released state. Kw ≈ 0 indicates that the ankle angle basically does not change. KRy(t - 1) > 0 ∩ KRy(t) < 0 indicates that the Euler angle of the calf exoskeleton 20 on the Y-axis is at the peak position, that is, it has stepped backward to the limit. At this time, it can be judged that the forefoot leaves the ground.

[0100] Combined with the above embodiments, the foot exoskeleton of the present application is set to include a foot main body, a forefoot main body and a rear foot sole plate. A certain distance is formed between the forefoot main body and the rear foot sole plate. When the user walks, the distance between the forefoot main body and the rear foot sole plate forms a periodic change. By the distance and the change of the distance between the forefoot main body and the rear foot sole plate, the rotation angle and the change of the angle of the ankle, the Euler angle of the Y-axis of the calf and the change of the Euler angle of the Y-axis, the collected data has high reliability, small calculation amount, and can accurately judge the postures of the leg and the foot to identify the postures of the current user's foot and leg.

[0101] Although the present invention has been disclosed above in preferred embodiments, it is not intended to limit the present invention. Those of ordinary skill in the technical field to which the present invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope defined in the claims.

Claims

1. A gait detection system based on a foot exoskeleton, characterized in that, Comprising: A foot exoskeleton (10) for wearing on a user's foot, the foot exoskeleton (10) including a foot main body (11), a forefoot bottom plate (12) and a rear foot bottom plate (13), the forefoot bottom plate (12) including a first connection end and a second connection end, the first connection end of the forefoot bottom plate (12) being connected to the foot main body (11), and the second connection end being connected to the rear foot bottom plate (13), with an elastic connection between the foot main body (11) and the rear foot bottom plate (13); A calf exoskeleton (20) connected to the foot main body (11) and capable of rotating relative to the foot main body (11); A first detection unit (16) connected to the bottom of the foot main body (11) for detecting the distance between the foot main body (11) and the rear foot bottom plate (13); A second detection unit (21) connected at the pivot joint between the foot main body (11) and the calf exoskeleton (20) for detecting the rotation angle of the foot main body (11) relative to the calf exoskeleton (20). Defining the state where the foot main body (11) is perpendicular to the calf exoskeleton (20) as the initial state, plantar flexion movement of the foot as forward rotation, and dorsiflexion movement of the foot as reverse rotation; A third detection unit (22) connected to the calf exoskeleton (20) for detecting the Euler angle of the calf exoskeleton (20) on the Y-axis. Defining the state where the calf exoskeleton (20) is collinear with the body length direction as the initial position, the calf exoskeleton (20) being in front of the body as reverse rotation, and the calf exoskeleton (20) being behind the body as forward rotation; A controller electrically connected to the first detection unit (16), the second detection unit (21), and the third detection unit (22); Wherein, the controller obtains the distance h and the rate of change Kh of the distance between the foot main body (11) and the rear foot bottom plate (13) in the current state according to the first detection unit (16), the controller obtains the rotation angle w and the rate of change Kw of the rotation angle of the foot main body (11) relative to the calf exoskeleton (20) according to the second detection unit, and the controller obtains the Euler angle Ry and the rate of change KRy of the Euler angle of the calf exoskeleton (20) on the Y-axis in the current state according to the third detection unit (22); The controller determines the current posture of the foot exoskeleton (10) based on multiple parameters among h, Kh, w, Kw, Ry, and KRy.

2. The gait detection system based on a foot exoskeleton according to claim 1, wherein, The controller determines the force state of the rear foot bottom plate (13) based on the distance h and the rate of change Kh of the distance between the foot main body (11) and the rear foot bottom plate (13).

3. The gait detection system based on a foot exoskeleton according to claim 1, wherein Defining that when standing statically, the distance between the foot main body (11) and the rear foot bottom plate (13) is hl; the postures of the foot exoskeleton (10) include a first posture, a second posture, a third posture, and a fourth posture in the walking posture; The first posture is the heel of the foot exoskeleton (10) touching the ground; The second posture is that the forefoot of the foot exoskeleton (10) touches the ground, and a relative angle w between the foot exoskeleton (10) and the calf exoskeleton (20) is defined as w ∈ [w1, w2], and the Euler angle Ry of the calf exoskeleton (20) about the Y-axis is Ry ∈ [Ry1, Ry2]; The third posture is that the heel of the foot exoskeleton (10) leaves the ground; The fourth posture is that the forefoot of the foot exoskeleton (10) leaves the ground; When Kh < 0, Kw > 0, KRy(t - 1) < 0 ∩ KRy(t) > 0, the controller determines that the foot exoskeleton (10) is in the first posture; When h < hl, Kh > 0, Kw < 0, w ∈ [w1, w2], Ry ∈ [Ry1, Ry2], the controller determines that the foot exoskeleton (10) is in the second posture; When h > hl, w > 0, Kw > 0, KRy > 0, the controller determines that the foot exoskeleton (10) is in the third posture; When h > hl, Kh > 0, Kw ≈ 0, KRy(t - 1) > 0 ∩ KRy(t) < 0, the controller determines that the foot exoskeleton (10) is in the fourth posture.

4. The gait detection system based on a foot exoskeleton according to claim 1, characterized in that, An elastic element (15) is provided between the foot main body (11) and the rear foot sole plate (13), and a connecting plate (14) is also provided between the foot main body (11) and the rear foot sole plate (13). The elastic element (15), the rear foot sole plate (13) and the connecting plate (14) form a triangular structure, and the length of the side where the elastic element (15) is located is variable.

5. The gait detection system based on a foot exoskeleton according to claim 1, wherein The front foot sole plate (12) is configured as a flexible structure, and the distance between the first connection end and the second connection end of the front foot sole plate (12) is variable.

6. The gait detection system based on a foot exoskeleton according to claim 1, wherein, The first detection unit (16) includes a Hall sensor module. The Hall sensor module includes a Hall sensor provided at the bottom of the foot main body (11) and a permanent magnet provided at the upper part of the rear foot sole plate (13); the second detection unit (21) includes an angle sensor, and the third detection unit (22) includes an attitude sensor.

7. The gait detection system based on a foot exoskeleton according to claim 1, wherein The first detection unit (16) corresponds to the heel of the foot main body (11).

8. A gait detection method based on a foot exoskeleton, characterized in that, Using the gait detection system based on the foot exoskeleton according to any one of claims 1 - 7, includes the following steps: Step 1, real-time detect the distance h between the foot main body (11) and the rear foot sole plate (13) and the change rate Kh of the distance, the rotation angle w of the foot main body (11) relative to the calf exoskeleton (20) and the change rate Kw of the rotation angle, the Euler angle Ry of the calf exoskeleton (20) about the Y-axis and the change rate KRy of the Euler angle; Step 2, determine the current posture of the foot exoskeleton (10) according to multiple parameters among h, Kh, w, Kw, Ry and KRy.

9. The gait detection method based on a foot exoskeleton according to claim 8, wherein The postures of the foot exoskeleton (10) include the first posture, the second posture, the third posture and the fourth posture in the walking posture; When Kh < 0, Kw > 0, KRy(t - 1) < 0 ∩ KRy(t) > 0, it is determined that the foot exoskeleton (10) is in the first posture; When h < hl, Kh > 0, Kw < 0, w ∈ [w1, w2], and Ry ∈ [Ry1, Ry2], it is determined that the foot exoskeleton (10) is in the second posture; When h > hl, w > 0, Kw > 0, and KRy > 0, the controller determines that the foot exoskeleton (10) is in the third posture; When h > hl, Kh > 0, Kw ≈ 0, KRy(t - 1) > 0 ∩ KRy(t) < 0, the controller determines that the foot exoskeleton (10) is in the fourth posture.

Images