Exoskeleton bionic ankle system considering human gait spatial-temporal characteristics

Abstract

The invention discloses an exoskeleton bionic ankle system considering human gait spatial-temporal characteristics, and relates to the technical field of exoskeleton bionic ankle systems, the ankle system comprises a bionic arch mechanism, a foot movement mechanism and a foot recognition mechanism; wherein the bionic arch mechanism is used for supporting the foot of a wearer; the foot movement mechanism comprises an ankle-foot movement module, and the ankle-foot movement module is connected with the side part of the bionic foot arch mechanism; the top of the ankle-foot movement module is connected with an exoskeleton lower limb system; the foot recognition mechanism at least comprises a heel recognition module and a toe recognition module which are distributed at the heel position and the toe position of the bottom of the bionic foot arch mechanism, and the heel recognition module and the toe recognition module are connected with the bionic foot arch mechanism through floating structures so as to eliminate tension interference generated when the foot leaves the ground in the walking process. The ankle system is more fit with the gait of the human body in the walking process, and accurate pressure measurement of the front sole and the rear sole of the foot in the walking process of the human body can be achieved.

Description

Technical Field

[0001] The present application generally relates to the technical field of exoskeleton bionic ankle systems, and specifically to an exoskeleton bionic ankle system that takes into account the temporal and spatial characteristics of human gait. Background Art

[0002] In existing exoskeleton systems, plantar pressure detection modules often use flexible sensors or fixed layout designs. While these sensors can collect pressure data, they generally suffer from short service lives and limited applicability. Furthermore, most detection shoes utilize a closed structure to ensure signal stability, resulting in poor breathability, exacerbating foot sweat accumulation and frictional heat effects, and reducing wearer comfort.

[0003] Traditional rigid sensor detection shoes often embed pressure sensors into the hard insole substrate, resulting in excessive rigidity of the sole contact surface. Long-term use can easily cause arch fatigue and local pressure sores. At the same time, the sensor layout does not match the biomechanical distribution of the human foot and lacks dynamic fitting capabilities. Stress concentration is especially prone to occur in high-pressure areas such as the heel and metatarsal bones, affecting the naturalness of gait. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide an exoskeleton bionic ankle system that takes into account the temporal and spatial characteristics of human gait.

[0005] The present application provides an exoskeleton bionic ankle system that takes into account the temporal and spatial characteristics of human gait. The ankle system is used to connect to the exoskeleton lower limb system to link the wearer's calf and foot. The ankle system includes: A bionic arch mechanism, the bionic arch mechanism being used to support the wearer's foot; the bionic arch mechanism having a bionic curved surface for fitting the wearer's foot; the bionic arch mechanism being respectively provided with a foot movement mechanism and a foot recognition mechanism; The foot motion mechanism includes: an ankle-foot motion module, which is connected to the side of the bionic arch mechanism; the top of the ankle-foot motion module is connected to the exoskeleton lower limb system; the foot recognition mechanism includes at least: a heel recognition module and a toe recognition module distributed at the heel and toe of the bottom of the bionic arch mechanism, and the heel recognition module and the toe recognition module are both connected to the bionic arch mechanism through a floating structure to eliminate tension interference when the foot leaves the ground during walking.

[0006] According to the technical solution provided by the present application, the bionic arch mechanism includes: an ankle-foot connection section and a foot connection section; the ankle-foot motion module is disposed on the side wall of the ankle-foot connection section, the heel recognition module is disposed at the bottom of the ankle-foot connection section, and the toe recognition module is connected to the end of the foot connection section; wherein, a pull ring is provided at the ankle-foot connection section, and the pull ring is used to thread a strap to fix the wearer's foot; the outer shapes of the ankle-foot connection section and the foot connection section are in a bionic curved surface that fits the wearer's foot.

[0007] According to the technical solution provided by the present application, the ankle-foot motion module includes: a calf connecting rod and a connection structure, one end of the calf connecting rod is used to be connected to the exoskeleton lower limb system, and the other end thereof is connected to the bionic arch mechanism through the connection structure, and the connection structure is used to enable the ankle-foot system to simulate the human ankle joint to complete multi-degree-of-freedom motion.

[0008] According to the technical solution provided by the present application, the connection structure includes: A spherical plain bearing, the spherical plain bearing has a connecting column section and a bearing section; the connecting column section is threadedly connected to the calf connecting rod, and a through hole is provided in the middle of the bearing section; A dowel screw, the dowel screw has a first optical axis section and a first thread section, the first optical axis section is connected to the through hole to provide a degree of freedom for the calf connecting rod; An ankle-foot connecting member, the ankle-foot connecting member is located between the spherical plain bearing and the bionic arch mechanism, after the first thread section passes through the through hole and is threaded with the ankle-foot connecting member, it extends out from the connecting through hole on the side wall of the ankle-foot connection section, and is installed and fixed to the bionic arch mechanism through a locking connection assembly.

[0009] According to the technical solution provided by the present application, the heel recognition module includes: A flexible shoe, the heel part of the flexible shoe is fixed on the upper surface of the bionic arch mechanism, and the flexible shoe is used to contact the wearer's foot to form a foot support; A plantar pressure sensor, the plantar pressure sensor is installed in a first counterbore at the bottom of the ankle-foot connection section through a first floating structure; The first floating structure includes: A heel sensor mounting box, the heel sensor mounting box is connected to the side of the plantar pressure sensor away from the first counterbore, and the heel sensor mounting box is connected to the ankle-foot connection section through a first positioning screw; the first positioning screw has a second optical axis section and a second thread section, the second optical axis section is used to be connected to the heel sensor mounting box, the second thread section passes through the heel sensor mounting box and is connected to the bottom of the ankle-foot connection section, and the heel sensor mounting box can move along the axis direction of the first positioning screw relative to the bionic arch mechanism to eliminate the tension received by the heel sensor mounting box during walking.

[0010] According to the technical solution provided by the present application, the toe recognition module includes: A front sole connecting member, which is arranged at the toe part of the bottom of the flexible shoe, and its end is also connected to the end of the foot connecting section; a second counterbore is arranged on the side of the front sole connecting member away from the flexible shoe, and a toe pressure sensor is arranged in the second counterbore through a second floating structure, and the toe pressure sensor is used to collect the pressure of the wearer's toe part; The second floating structure includes: A toe sensor mounting box, which is connected to the side of the toe pressure sensor away from the front sole connecting member, and the toe sensor mounting box is connected to the front sole connecting member through a second positioning screw; the second positioning screw has a third optical axis section and a third thread section, the third optical axis section is used to connect to the toe sensor mounting box, the third thread section will be connected to the bottom of the flexible shoe through the toe sensor mounting box, and the toe sensor mounting box can move along the axis direction of the second positioning screw relative to the flexible shoe to eliminate the tension received by the toe sensor mounting box during walking.

[0011] According to the technical solution provided by the present application, two corresponding convex structures are arranged at the end of the foot connecting section, and the convex structures include two semi-circular protrusions arranged from top to bottom; the two semi-circular protrusions are concentrically arranged, and the radius of the semi-circular protrusion located above is smaller than the radius of the other semi-circular protrusion; A first mounting hole is provided on the convex structure, and a connecting through hole matching the first mounting hole is provided at the end of the front sole connecting member. The first mounting hole and the connecting through hole cooperate with the metatarsophalangeal joint motion module to movably connect the foot connecting section and the front sole connecting member, and the metatarsophalangeal joint motion module is used to simulate the flexion and extension freedom of the human metatarsophalangeal joint and limit the movement range of the front sole connecting member.

[0012] According to the technical solution provided by the present application, a second mounting hole is further provided on the convex structure, the second mounting hole is located below the first mounting hole and is concentric with the first mounting hole; a limiting protrusion is provided at the end of the front sole connecting member for connecting with the convex structure; The metatarsophalangeal joint motion module includes: A first elastic card and a first pin shaft that cooperate with each other. The connecting through hole and the first mounting hole are connected by the first elastic card and the first pin shaft, and the front sole connecting member and the bionic arch mechanism can rotate relative to each other along the axis of the first pin shaft to realize the freedom of the wearer's metatarsophalangeal joint; A second pin shaft and a second elastic card that cooperate with each other. The second pin shaft is fixed between the two second mounting holes through the second elastic card. The second pin shaft restricts the movement range of the front foot connecting member through cooperation with the limiting protrusion.

[0013] According to the technical solution provided by the present application, a rubber sole and a rubber toe cap are respectively provided at the bottom of the ankle-foot connection section and the bottom of the flexible shoe; a gasket is provided at the bottom of the bionic arch mechanism.

[0014] In summary, the present technical solution specifically discloses an exoskeleton bionic foot and ankle system that considers the spatio-temporal characteristics of human gait. The system includes: a bionic arch mechanism for supporting the wearer's foot; the bionic arch mechanism has a bionic curved surface for fitting the wearer's foot; a foot movement mechanism and a foot recognition mechanism are respectively provided on the bionic arch mechanism; the foot movement mechanism includes: an ankle-foot movement module connected to the side of the bionic arch mechanism; the top of the ankle-foot movement module is connected to the exoskeleton lower limb system; the foot recognition mechanism at least includes: a heel recognition module and a toe recognition module distributed at the heel and toe of the bottom of the bionic arch mechanism, and both the heel recognition module and the toe recognition module are connected to the bionic arch mechanism through a floating structure to eliminate the tensile interference when the foot leaves the ground during walking.

[0015] In the existing foot and ankle system, the traditional sensor layout does not match the biomechanical distribution of the human foot, lacking dynamic fitting ability. Especially in high-pressure areas such as the heel and metatarsal bones, stress concentration is prone to occur, resulting in low pressure acquisition accuracy and unable to provide accurate information for judging the wearer's action intention. Through the setting of the ankle-foot movement module in the present application, the compound movement of ankle pitching and rotation is realized, so as to fit the human walking posture; by setting the heel recognition module and the toe recognition module with floating structures, the lateral tensile interference when the heel or toe leaves the ground can be eliminated. At the same time, the elastic rubber toe cap and the floating structure at the toe recognition module can also synchronously capture the ground impact force. The heel recognition module and the toe recognition module jointly achieve high-precision recognition of gait phase. Description of the Drawings

[0016] By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, purposes and advantages of the present application will become more obvious: Figure 1 It is a schematic structural diagram of an exoskeleton bionic foot and ankle system that considers the spatio-temporal characteristics of human gait; Figure 2 It is a schematic structural diagram of the ankle-foot movement module; Figure 3 It is a schematic structural diagram of the heel recognition module; Figure 4 It is a schematic structural diagram of the toe recognition module; Figure 5 It is a structural schematic diagram of a metatarsophalangeal joint motion module; Figure 6 It is a structural schematic diagram of a bionic arch mechanism.

[0017] Reference numerals in the figure: 1, ankle-foot motion module; 2, heel recognition module; 3, toe recognition module; 4, metatarsophalangeal joint motion module; 101, calf connecting rod; 102, dowel screw; 103, first anti-slip gasket; 104, spherical plain bearing; 1041, connecting column section; 1042, bearing section; 105, ankle-foot connecting piece; 106, second anti-slip gasket; 108, first pair of opposing nuts; 109, second pair of opposing nuts; 201, heel fixing plate; 202, flexible shoe; 203, plantar pressure sensor; 204, third pair of opposing nuts; 205, heel sensor mounting box; 206, first positioning screw; 207, rubber sole; 301, toe fixing plate; 302, forefoot connecting piece; 3021, second counterbore; 3022, connecting hole; 3023, limiting projection; 303, toe sensor mounting box; 304, rubber toe cap; 305, toe pressure sensor; 401, first pin shaft; 402, gasket; 403, second elastic card; 404, first elastic card; 405, second pin shaft; 5, bionic arch mechanism; 51, ankle-foot connection section; 510, connection through hole; 511, first counterbore; 52, foot connection section; 501, pull ring; 521, protruding structure; 5211, first mounting hole; 5212, second mounting hole. Specific embodiments

[0018] The following further elaborates on the present application in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are merely for explaining the related invention and not for limiting the invention. Additionally, it should be noted that for ease of description, only the parts related to the invention are shown in the drawings.

[0019] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will detail the present application with reference to the drawings and embodiments.

[0020] Embodiment 1 To make the technical solutions of the embodiments of the present application clearer and easier to understand, the application background provided by the embodiments of the present application is introduced below.

[0021] In modern exoskeleton systems, the plantar pressure detection module, as the core sensing unit for human-machine interaction, directly determines the accuracy of the system's capture of human motion intentions and the control response efficiency. Whether it is assisting patients in restoring walking function in the field of medical rehabilitation or enhancing the load-bearing capacity of wearers in industrial and military scenarios, accurately obtaining plantar pressure distribution data is the key prerequisite for realizing exoskeleton adaptive assistance and preventing sports injuries. However, the current plantar pressure detection technology in exoskeleton systems still faces many challenges. Most existing plantar pressure detection modules adopt flexible sensors or fixed-layout designs. Although they can basically collect pressure data, they generally have the problem of short service life. Limited by material properties, flexible sensors are prone to structural fatigue and signal attenuation during repeated bending and extrusion, making it difficult to meet the needs of long-term wear of exoskeletons. The fixed-layout design has severely limited applicable scenarios due to its lack of adaptability to the morphological differences of different individuals' feet and changes in motion states. At the same time, to ensure the stability of signal transmission, most detection shoes adopt a closed structure, which greatly weakens the breathability of the shoes. During long-term wear, the closed structure exacerbates foot sweat accumulation and frictional heat effects. Traditional rigid sensor detection shoes also have significant drawbacks. Such detection shoes usually embed pressure sensors in a hard insole substrate, resulting in too high rigidity on the plantar contact surface and destroying the natural mechanical buffering mechanism of the human foot. During long-term use by wearers, it is extremely easy to cause arch fatigue and even local pressure sores. More critically, the existing sensor layout fails to fully consider the characteristics of the biomechanical distribution of the human foot and lacks the ability of dynamic fitting. During human movements such as walking and running, serious stress concentration phenomena occur in high-pressure areas such as the heel and metatarsal bones, which not only affects the naturalness of the wearer's gait but may also cause irreversible damage to the foot bones and joints, restricting the popularization and development of exoskeleton systems in practical applications.

[0022] In view of this, please refer to Figure 1 the structural schematic diagram of a bionic foot and ankle system for an exoskeleton considering the spatio-temporal characteristics of human gait provided in this embodiment shown in the figure. This bionic foot and ankle system for an exoskeleton fits better with the gait during the human walking process, can accurately measure the pressure on the front and rear soles of the wearer during walking, and can then judge the action intentions of the wearer such as walking, standing, going uphill and downhill in real time, so as to dynamically adjust the assistance direction and strength to achieve the coordinated movement of "man-machine integration". Specifically, the bionic foot and ankle system for an exoskeleton includes: A bionic arch mechanism 5, which is used to support the wearer's foot; the bionic arch mechanism 5 has a bionic curved surface for fitting the wearer's foot; a foot movement mechanism and a foot recognition mechanism are respectively arranged on the bionic arch mechanism 5; The foot motion mechanism includes: an ankle-foot motion module 1, which is connected to the side of the bionic arch mechanism 5; the top of the ankle-foot motion module 1 is connected to the exoskeleton lower limb system; the foot recognition mechanism includes at least: a heel recognition module 2 and a toe recognition module 3 distributed at the heel and toe of the bottom of the bionic arch mechanism 5, and the heel recognition module 2 and the toe recognition module 3 are both connected to the bionic arch mechanism 5 through a floating structure to eliminate the tension interference when the foot leaves the ground during walking.

[0023] Specifically, the bionic arch mechanism 5 is used to support the wearer's foot and is mainly worn on the wearer's ankle and heel. At the same time, the bionic arch mechanism 5 is designed to obtain a bionic surface based on the biomechanical curve of the human plantar, which can effectively adapt to the deformation of the arch during the gait cycle, achieve the effect of dynamic fitting of the arch and center of gravity transfer, and ensure the smoothness of the gait; in addition, the bionic arch mechanism is also provided with a foot movement mechanism and a foot recognition mechanism. The foot movement mechanism is used to simulate the multi-degree-of-freedom movement of the human foot joints, and the foot recognition mechanism is used to collect the pressure distribution of the heel area and the toe area during the wearer's walking.

[0024] Furthermore, the foot motion mechanism includes: an ankle-foot motion module 1; as the name suggests, the ankle-foot motion module 1 is installed at the ankle of the wearer, and it is also used to connect the calf section of the exoskeleton lower limb system, so that the human foot and lower limb system can be linked and controlled; the foot recognition mechanism includes at least: a heel recognition module 2 and a toe recognition module 3, both of which are connected to the bionic arch mechanism 5 through corresponding floating structures, so that it can float and cooperate with the bionic arch mechanism 5, avoiding the situation where the wearer's heel leaves the ground while walking due to excessive lateral tension interference under traditional rigid connection, and can effectively improve the pressure detection accuracy, so that the entire foot recognition mechanism can realize the function of gait phase recognition under the joint control of the toe and heel recognition modules, thereby dynamically adjusting the power assistance direction and strength to achieve "human-machine integration" collaborative movement.

[0025] In a preferred embodiment, the bionic arch mechanism 5 includes: an ankle-foot connecting section 51 and a foot connecting section 52; the ankle-foot motion module 1 is arranged on the side wall of the ankle-foot connecting section 51, the heel recognition module 2 is arranged at the bottom of the ankle-foot connecting section 51, and the toe recognition module 3 is connected to the end of the foot connecting section 52; wherein, a pull ring 501 is provided at the ankle-foot connecting section 51, and the pull ring 501 is used to thread a strap to fix the wearer's foot; the outer shapes of the ankle-foot connecting section 51 and the foot connecting section 52 are bionic curves that fit the wearer's foot.

[0026] Specifically, the bionic arch mechanism 5 includes an ankle-foot connection segment 51 and a foot connection segment 52. The ankle-foot connection segment 51 and the foot connection segment 52 present the arch shape from the metatarsophalangeal joint to the heel end of the human body. The entire bionic arch mechanism 5 is also designed with a better-fitting curved surface support structure according to the human body structure to make it more fitting with the gait during human walking. The ankle-foot motion module 1, the heel recognition module 2, and the toe recognition module 3 are arranged at corresponding positions on the bionic arch mechanism 5 according to the human body structure. Since the exoskeleton bionic ankle-foot system also needs to be fixed to the wearer, multiple pull rings 501 are provided at the ankle-foot connection segment 51. The pull rings 501 can be polyether ether ketone pull rings and are connected to the bionic arch mechanism 5 by rivets. During actual use, the pull rings 501 fix the feet of the wearer through the magic tape straps threaded through them.

[0027] In a preferred embodiment, referring to Figure 2 , the ankle-foot motion module 1 includes: a calf connecting rod 101 and a connection structure. One end of the calf connecting rod 101 is used to connect to the exoskeleton lower limb system, and the other end is connected to the bionic arch mechanism 5 through the connection structure. The connection structure is used to enable the ankle-foot system to simulate the multi-degree-of-freedom movement of the human ankle joint.

[0028] To ensure the degree of freedom of the human ankle joint during actual walking, the calf connecting rod 101 in the ankle-foot motion module 1 is rigidly connected to the bionic arch mechanism 5 through the designed connection structure. At the same time, the calf connecting rod 101 itself and the connection structure are also movably connected (here, the movable connection means that the calf connecting rod 101 can move within a small range). Therefore, the calf connecting rod 101 not only forms the starting point of the force transmission of the main support frame of the sole but also realizes the multi-degree-of-freedom rotation of the ankle joint in the sagittal plane and the coronal plane, ensuring the fitting of the wearer's foot movement.

[0029] Further, the aforementioned connection structure includes: a spherical plain bearing 104, and the spherical plain bearing 104 has a connection column section 1041 and a bearing section 1042; the connection column section 1041 is threadedly connected to the calf connecting rod 101, and a through hole is provided in the middle of the bearing section 1042; A set screw 102, the set screw 102 has a first optical axis section and a first threaded section, and the first optical axis section is connected to the through hole to provide freedom of movement for the calf connecting rod 101; An ankle-foot connector 105 is located between the spherical plain bearing 104 and the bionic arch mechanism 5. After the first threaded section is threadedly connected to the ankle-foot connector 105 through the through hole, it extends out from the connection through hole 510 on the side wall of the ankle-foot connection segment 51 and is installed and fixed to the bionic arch mechanism 5 through a locking connection assembly.

[0030] Specifically, the connection structure includes: a spherical plain bearing 104, a dowel screw 102, an ankle-foot connecting member 105, a first pair of opposing nuts 108, a first anti-slip gasket 103, a second anti-slip gasket 106, and a second pair of opposing nuts 109. An internal threaded hole is provided at the end of the lower leg connecting rod 101. The connecting column section 1041 of the spherical plain bearing 104 is an external threaded rod. The second pair of opposing nuts 109 is installed on the connecting column section 1041 of the spherical plain bearing 104. After the spherical plain bearing 104 is threadedly connected to the lower leg connecting rod 101, the second pair of opposing nuts 109 is rotated to press against the end face of the lower leg connecting rod 101 to achieve thread pre-tightening. The dowel screw 102 includes two stepped connecting sections. One connecting section is a first smooth shaft section, and the other connecting section is a first threaded section. Among them, the first smooth shaft section is closer to the outside of the ankle-foot system relative to the first threaded section. The aforementioned locking connection assembly is composed of connecting members such as "the first pair of opposing nuts 108, the first anti-slip gasket 103, the second anti-slip gasket 106, and the second pair of opposing nuts 109".

[0031] During the connection process of the dowel screw 102 with various components, the dowel screw 102 needs to pass through the first anti-slip gasket 103, the inner ring of the bearing section 1042, the second anti-slip gasket 106, and the ankle-foot connecting member 105 in sequence and then be connected to the ankle-foot connecting section 51 of the bionic arch mechanism 5. After connection, the first smooth shaft section corresponds to the first anti-slip gasket 103 and the bearing section 1042, while the first threaded section is threadedly connected to the ankle-foot connecting member 105, the second anti-slip gasket 106, and the connection through hole 510, and is finally fixed to the bionic arch mechanism 5 through the screwing of the second pair of opposing nuts 109 with the first threaded section. Based on the above connection description, it can be seen that the lower leg connecting rod 101 is connected to the spherical plain bearing 104 at the first smooth shaft section to achieve the combined movement of ankle pitch and rotation, ensuring the fit between the human and the device at the ankle joint.

[0032] In a preferred embodiment, refer to Figure 3 , the heel recognition module 2 includes: A flexible shoe 202, the heel part of the flexible shoe 202 is fixed on the upper surface of the bionic arch mechanism 5. The flexible shoe 202 is used to contact the wearer's foot to form foot support; A plantar pressure sensor 203, the plantar pressure sensor 203 is installed in the first counterbore 511 at the bottom of the ankle-foot connecting section 51 through a first floating structure; The first floating structure includes: a heel sensor mounting box 205, which is connected to the side of the plantar pressure sensor 203 away from the first counterbore 511, and the heel sensor mounting box 205 is connected to the ankle-foot connecting section 51 by a first positioning screw 206; the first positioning screw 206 has a first optical axis section and a first threaded section. The first optical axis section is used to connect to the heel sensor mounting box 205, and the first threaded section passes through the heel sensor mounting box 205 and is connected to the bottom of the ankle-foot connecting section 51. The heel sensor mounting box 205 can move along the axis direction of the first positioning screw 206 relative to the bionic arch mechanism 5 to eliminate the tensile force received by the heel sensor mounting box 205 during walking.

[0033] Specifically, the heel recognition module 2 includes: a flexible shoe 202, a plantar pressure sensor 203, and a first floating structure. The flexible shoe 202 can provide wearing comfort for the ankle-foot system. The plantar pressure sensor 203 is used to collect the pressure value in the heel area. The first floating structure makes the plantar pressure sensor 203 not directly fixed to the bionic arch mechanism 5; when the friction between the sole and the ground and the inertia of foot movement generate lateral tensile forces, the tensile forces can be converted into axial displacements instead of directly pulling the plantar pressure sensor 203, thereby avoiding the direct action of lateral tensile forces on the sensor, and effectively eliminating interference and improving the pressure detection accuracy.

[0034] Furthermore, the first floating structure includes: a heel sensor mounting box 205, a first positioning screw 206, a rear heel fixing plate 201, and a third pair of opposing nuts 204; during the connection process, corresponding through holes are provided at the rear heel of the flexible shoe 202 and on the rear heel fixing plate 201, and corresponding threaded holes are provided on the bionic arch mechanism 5, and the two can be fixed through connecting parts (such as bolts); a first counterbore 511 is provided at the bottom of the bionic arch mechanism 5 as the mounting end face of the plantar pressure sensor 203. The other side of the plantar pressure sensor 203 is connected to the heel sensor mounting box 205. The heel sensor mounting box 205 is provided with a flange. The second optical axis section of the first positioning screw 206 passes through the flange hole on the flange of the heel sensor mounting box 205 to enable the heel sensor mounting box 205 to move freely along the axis of the first positioning screw 206, and the second threaded shaft section is screwed into the bottom of the bionic arch mechanism 5 for relative fixation. In this way, the heel sensor mounting box 205 and the plantar pressure sensor 203 connected thereto can move in a small range along the axis direction of the first positioning screw 206 relative to the bionic arch mechanism 5, achieving the effect of effectively eliminating interference and improving the pressure detection accuracy.

[0035] In a preferred embodiment, referring to Figure 4 , the toe recognition module 3 includes: The front sole connecting member 302 is disposed at the toe portion of the bottom of the flexible shoe 202, and its end is also connected to the end of the foot connecting section 52; on the side of the front sole connecting member 302 away from the flexible shoe 202, a second counterbore 3021 is provided, and a toe pressure sensor 305 is provided in the second counterbore 3021 through a second floating structure. The toe pressure sensor 305 is used to collect the pressure at the toe portion of the wearer. The second floating structure includes: a toe sensor mounting box 303, which is connected to the side of the toe pressure sensor 305 away from the front sole connecting member 302, and the toe sensor mounting box 303 is connected to the front sole connecting member 302 by a second positioning screw; the second positioning screw has a third optical axis section and a third threaded section. The third optical axis section is used to connect to the toe sensor mounting box 303, and the third threaded section will be connected to the bottom of the flexible shoe 202 through the toe sensor mounting box 303. The toe sensor mounting box 303 can move along the axis direction of the second positioning screw relative to the flexible shoe 202 to eliminate the tension received by the toe sensor mounting box 303 during walking.

[0036] The toe recognition module 3 is provided with a second floating structure similar to the aforementioned heel recognition module 2 to eliminate the tension received at the toe, thereby improving the pressure recognition accuracy of the toe recognition module 3; in addition, the toe recognition module 3 includes a front sole connecting member 302, and its end can be connected to the end of the bionic arch mechanism 5, which is equivalent to being connected to the metatarsophalangeal joint of the human body. The top end surface of the front sole connecting member 302 is connected to the toe portion of the bottom of the flexible shoe 202. It can be understood that the entire front sole connecting member 302 serves as a support member for the front sole of the wearer's foot; the toe pressure sensor 305 here is used to collect the pressure value in the toe area.

[0037] Further, the second floating structure includes: the toe fixing plate 301, the front sole connecting member 302, and the toe sensor mounting box 303 are also fixed by a connecting member. The second counterbore 3021 at the bottom of the front sole connecting member 302 forms the mounting end surface of the toe pressure sensor 305. The third optical axis section of the second positioning screw passes through the flange hole of the toe sensor mounting box 303 and is threadedly connected to the front sole connecting member 302 by its third threaded section. At this time, the toe sensor mounting box 303 and the toe pressure sensor 305 connected thereto can move in a small range along the axis direction of the second positioning screw relative to the bionic arch mechanism 5, achieving the effect of effectively eliminating interference and improving the pressure detection accuracy.

[0038] In a preferred embodiment, refer to Figure 4 、 Figure 5 and Figure 6, two corresponding convex structures 521 are provided at the end of the foot connection section 52. The convex structure 521 includes two semi-circular protrusions arranged from top to bottom; the two semi-circular protrusions are concentrically arranged, and the radius of the semi-circular protrusion located above is smaller than the radius of the other semi-circular protrusion; A first mounting hole 5211 is formed in the convex structure 521, and a connection hole 3022 matching the first mounting hole 5211 is provided at the end of the front sole connecting member 302. The first mounting hole 5211 and the connection hole 3022 cooperate with the metatarsophalangeal joint motion module 4 to movably connect the foot connection section 52 and the front sole connecting member 302. The metatarsophalangeal joint motion module 4 is used to simulate the flexion and extension freedom of the human metatarsophalangeal joint and limit the movement range of the front sole connecting member 302.

[0039] Specifically, the connection between the front sole connecting member 302 and the bionic arch mechanism 5 is located at the human metatarsophalangeal joint, and a certain degree of joint flexion and extension freedom is also required. Therefore, the front sole connecting member 302 and the bionic arch mechanism 5 are connected through the metatarsophalangeal joint motion module 4. Among them, two corresponding convex structures 521 are provided at the end of the foot connection section 52. The convex structure 521 is the core structure connected to the end of the front sole connecting member 302. The bottom of the convex structure 521 is semi-circular and can act as a semi-circular roller, so that the process of the center of gravity shifting from the rear sole to the front sole during the actual walking of the wearer is smoother and the human-machine interaction is more compliant; under the connection of the metatarsophalangeal joint motion module 4, the front sole connecting member 302 and the bionic arch mechanism 5 are not directly fixed and have a certain movable range, allowing the front sole connecting member 302 to perform flexion movement relative to the arch. At the same time, the metatarsophalangeal joint motion module 4 can also achieve hard limit of movement through limit design with the help of mechanical interference to avoid joint overload.

[0040] Specifically, a second mounting hole 5212 is also formed in the convex structure 521. The second mounting hole 5212 is located below the first mounting hole 5211 and is concentrically arranged with the first mounting hole 5211; a limit protrusion 3023 is provided at the end of the front sole connecting member 302 for connecting with the convex structure 521; The metatarsophalangeal joint motion module 4 includes: a first elastic card 404 and a first pin shaft 401 that cooperate with each other. The connection hole 3022 and the first mounting hole 5211 are connected by the first elastic card 404 and the first pin shaft 401, and the front sole connecting member 302 and the bionic arch mechanism 5 can rotate relative to each other along the axis of the first pin shaft 401 to achieve the movement freedom of the wearer's metatarsophalangeal joint; A second pin shaft 405 and a second elastic card 403 that cooperate with each other. The second pin shaft 405 is fixed between the two second mounting holes 5212 by the second elastic card 403. The second pin shaft 405 restricts the movement range of the front sole connecting member 302 through cooperation with the limit protrusion 3023.

[0041] Specifically, the metatarsophalangeal joint motion module 4 includes: a first pin shaft 401, a first elastic card 404, a second elastic card 403, and a second pin shaft 405. The first pin shaft 401 sequentially passes through the first mounting hole 5211 and the connecting hole 3022, and then its end is fixed with the first elastic card 404. At this time, a clearance fit is formed between the first pin shaft 401 and the front sole connecting member 302 and the bionic arch mechanism 5. The front sole connecting member 302 and the bionic arch mechanism 5 can rotate relative to each other along the first pin shaft 401 to realize the degree of freedom of the wearer's metatarsophalangeal joint and improve the fitting of the plantar structure.

[0042] In addition, a second mounting hole 5212 with a slightly smaller aperture is further provided below the first mounting hole 5211 of the bionic arch mechanism 5. The two are coaxially arranged to ensure coordination. After the second pin shaft 405 passes through the second mounting hole 5212 on the two protruding structures 521, its end is fixed with the second elastic card 403; in the embodiment of the present application, a limiting protrusion 3023 is provided at the connection between the front sole connecting member 302 and the bionic arch mechanism 5. The limiting protrusion 3023 is arranged adjacent to the second pin shaft 405, and when the front sole connecting member 302 moves to the limit position, the limiting protrusion 3023 will be locked against the second pin shaft 405 to realize the limit within the corresponding angle range and prevent the front sole connecting member 302 from moving beyond the limit.

[0043] In a preferred embodiment, a rubber sole 207 and a rubber toe cap 304 are respectively provided at the bottom of the ankle-foot connection section 51 and the bottom of the flexible shoe 202; a gasket 402 is provided at the bottom of the bionic arch mechanism 5.

[0044] Specifically, the rubber sole 207 and the rubber toe cap 304 can be respectively connected to the externally reserved mounting through holes of the heel sensor mounting box 205 and the toe sensor mounting box 303 through connectors. The rubber sole 207 and the rubber toe cap 304 can not only improve the wearing comfort but also absorb a little tensile energy when a lateral tensile force is generated, thereby improving the recognition accuracy of the sensor. The gasket 402 at the bottom of the bionic arch mechanism 5 can be made of a polyurethane gasket, which can play a role in buffering and reducing friction.

[0045] Based on the above description, the working principle of the exoskeleton bionic foot and ankle system considering the spatio-temporal characteristics of human gait provided by the present application is as follows: Connect the calf connecting rod 101 of the ankle-foot motion module 1 to the lower exoskeleton system, tighten the second pair of top nuts 109 on the spherical eye bearing 104, and pre-tighten it to a moderate resistance. The wearer puts the foot into the flexible shoe 202, adjusts the positions of the rubber sole 207 of the heel and toe recognition module and the rubber toe tip 304 so that the center of the heel aligns with the corresponding heel sensor mounting box 205 and toe sensor mounting box 303 (the metatarsal area of the forefoot is aligned with the toe sensor), and then inserts and tightens the Velcro straps in the pull rings on both sides of the heel to ensure that the foot does not slide and there is no local strong compression feeling. After wearing, the wearer can walk normally. During walking, the toe pressure sensor 305 can reflect the pressure changes in the metatarsophalangeal joint area and toe area in real time. At the same time, the plantar pressure sensor 203 can collect the pressure distribution at the heel. By the pressure changes of the front and rear soles, different gait phases can be distinguished, thus providing judgment conditions for the switching of the exoskeleton assistance mode.

[0046] In addition, the structural advantages of this application are as follows: (1) Explanation of the structure: The ankle-foot motion module 1 is used to connect the lower exoskeleton segment and simulate the multi-degree-of-freedom motion of the human ankle joint. Through the coordinated action of the connection structure, the combined motion of ankle pitching and rotation is realized to ensure the fit between the human and the device at the ankle joint; The heel recognition module 2 is connected to the bionic arch mechanism 5 through the first floating structure to collect the pressure distribution in the heel area. It includes an array of plantar pressure sensors 203 embedded in the flexible shoe 202, and realizes the floating fit by using the first positioning screw 206 and the auxiliary elastic gasket in the first floating structure to eliminate the lateral pulling interference when the heel leaves the ground during walking and improve the pressure detection accuracy; In addition to the design of the second floating structure at the toe recognition module 3, it is integrated in the forefoot area. Because it includes the forefoot connecting piece 302 and the rubber toe tip 304 assembly, it adapts to the gait touchdown buffer, and combines with the heel recognition module 2 to realize the function of gait phase recognition; The metatarsophalangeal joint motion module 4 is used to simulate the flexion and extension degrees of freedom of the human metatarsophalangeal joint and limit the motion range. It adopts a combined structure of double pin shaft hinge limit, allows the forefoot to flex relative to the arch, and realizes the hard limit of motion through the mechanical interference of the boss and the pin shaft at the limit position to avoid joint overload; The bionic arch mechanism 5 realizes the dynamic fit of the arch and the center of gravity transfer through the bionic curved surface support and the roller guiding structure of the convex structure 521; the bionic arch mechanism 5 is made of polyether ether ketone material and is designed according to the biomechanical curve of the human plantar. It adapts to the arch deformation during the gait cycle. The convex structure 521 is embedded at the end of the arch to reduce the frictional resistance of the center of gravity transfer from the heel to the forefoot and improve the smoothness of the gait.

[0047] (2) Description of the effects of structural design: The exoskeleton calf connecting rod 101 is rigidly connected to the bionic arch mechanism 5 via the flange structure of the ankle-foot motion module 1, forming the force transmission starting point of the main plantar support frame. This enables the ankle joint to rotate in multiple degrees of freedom in the sagittal and coronal planes, ensuring a consistent fit for the wearer's foot movements. The front end of the bionic arch mechanism 5 is flexibly connected to the metatarsophalangeal joint motion mechanism, while the rear end is flexibly connected to the heel recognition module 2 via an axial floating structure. Its curved support layer is designed based on the biomechanical curve of the human arch. Combined with the semicircular roller guidance of the terminal protrusion structure 521, it adapts to arch deformation during the gait cycle and reduces frictional resistance to weight transfer, achieving dynamic load distribution of plantar pressure.

[0048] The heel recognition module 2 and the toe recognition module 3 are respectively integrated into the rear end of the bionic arch mechanism 5 and the front end of the metatarsophalangeal joint motion module 4. The heel recognition module 2 eliminates lateral tension interference through the axial floating design of the first positioning screw 206, and the toe recognition module 3 uses the elastic rubber toe 304 and the floating structure to synchronously capture the impact force of touching the ground. The two are combined to achieve high-precision recognition of gait phase. The metatarsophalangeal joint motion module 4 balances load transfer and freedom of movement through a double-pin hinge and mechanical limit design, allowing the forefoot to flex relative to the arch of the foot, and performs limit interference at the extreme position to prevent joint overload and ensure wearing safety. In addition, the flexible shoe 202 serves as a packaging carrier for human-computer interaction, integrating various mechanical modules and detection components together, combining the wearing comfort and force transmission of ordinary shoes, and achieving pressure detection accuracy and reliability.

[0049] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features having similar functions disclosed in this application.

Claims

1. An exoskeleton bionic ankle-foot system considering the spatio-temporal characteristics of human gait, characterized in that, The ankle system is used to connect to the exoskeleton lower limb system to link the wearer's calf and foot. The ankle system includes: A bionic arch mechanism (5), the bionic arch mechanism (5) being used to support a wearer's foot; the bionic arch mechanism (5) having a bionic curved surface for fitting the wearer's foot; and a foot movement mechanism and a foot recognition mechanism being respectively provided on the bionic arch mechanism (5); The foot motion mechanism comprises: an ankle-foot motion module (1), the ankle-foot motion module (1) is connected to the side of the bionic arch mechanism (5); the top of the ankle-foot motion module (1) is connected to the exoskeleton lower limb system; the foot recognition mechanism at least comprises: a heel recognition module (2) and a toe recognition module (3) distributed at the heel and toe of the bottom of the bionic arch mechanism (5), and the heel recognition module (2) and the toe recognition module (3) are both connected to the bionic arch mechanism (5) through a floating structure to eliminate tension interference when the foot leaves the ground during walking.

2. The exoskeleton bionic ankle-foot system considering the spatio-temporal characteristics of human gait according to claim 1, wherein The bionic arch mechanism (5) comprises: an ankle-foot connecting section (51) and a foot connecting section (52); the ankle-foot motion module (1) is arranged on the side wall of the ankle-foot connecting section (51), the heel recognition module (2) is arranged on the bottom of the ankle-foot connecting section (51), and the toe recognition module (3) is connected to the end of the foot connecting section (52); wherein, a pull ring (501) is provided at the ankle-foot connecting section (51), and the pull ring (501) is used to wear a strap to fix the wearer's foot; the outer shapes of the ankle-foot connecting section (51) and the foot connecting section (52) are bionic curved surfaces that fit the wearer's foot.

3. The exoskeleton bionic ankle-foot system considering the spatio-temporal characteristics of human gait according to claim 2, wherein The ankle-foot motion module (1) comprises: a calf connecting rod (101) and a connecting structure, wherein one end of the calf connecting rod (101) is used to be connected to the exoskeleton lower limb system, and the other end thereof is connected to the bionic arch mechanism (5) through the connecting structure, and the connecting structure is used to enable the ankle-foot system to simulate the human ankle joint to complete multi-degree-of-freedom motion.

4. The exoskeleton bionic foot and ankle system considering the spatio-temporal characteristics of human gait according to claim 3, characterized in that The connection structure includes: A fisheye bearing (104), the fisheye bearing (104) comprising a connecting column section (1041) and a bearing section (1042); the connecting column section (1041) is threadedly connected to the shank connecting rod (101), and a through hole is formed in the middle of the bearing section (1042); a driving screw (102), the driving screw (102) having a first optical axis section and a first threaded section, the first optical axis section being connected to the through hole to provide a degree of freedom for the calf connecting rod (101); An ankle-foot connector (105), the ankle-foot connector (105) is located between the fisheye bearing (104) and the bionic arch mechanism (5), the first threaded section being threaded with the ankle-foot connector (105) through the through hole, extending from the connecting through hole (510) on the side wall of the ankle-foot connector (51), and being mounted and fixed to the bionic arch mechanism (5) through a locking connection assembly.

5. The exoskeleton bionic ankle-foot system considering the spatio-temporal characteristics of human gait according to claim 4, wherein The heel recognition module (2) comprises: Flexible shoe (202), the heel part of the flexible shoe (202) is fixed on the upper surface of the bionic arch mechanism (5), and the flexible shoe (202) is used to contact the wearer's foot to form foot support; Plantar pressure sensor (203), the plantar pressure sensor (203) is installed in the first counterbore (511) at the bottom of the ankle-foot connection section (51) through the first floating structure; The first floating structure includes: Heel sensor mounting box (205), the heel sensor mounting box (205) is connected to the side of the plantar pressure sensor (203) away from the first counterbore (511), and the heel sensor mounting box (205) is connected to the ankle-foot connection section (51) through the first positioning screw (206); the first positioning screw (206) has a second optical axis section and a second thread section, the second optical axis section is used to connect to the heel sensor mounting box (205), and the second thread section will be connected to the bottom of the ankle-foot connection section (51) via the heel sensor mounting box (205), and the heel sensor mounting box (205) can move along the axis direction of the first positioning screw (206) relative to the bionic arch mechanism (5) to eliminate the tension received by the heel sensor mounting box (205) during walking.

6. The exoskeleton bionic ankle-foot system considering the spatio-temporal characteristics of human gait according to claim 5, characterized in that, The toe recognition module (3) includes: Forefoot connecting piece (302), the forefoot connecting piece (302) is arranged at the toe part of the bottom of the flexible shoe (202), and its end is also connected to the end of the foot connecting section (52); a second counterbore (3021) is arranged on the side of the forefoot connecting piece (302) away from the flexible shoe (202), and a toe pressure sensor (305) is arranged in the second counterbore (3021) through the second floating structure, and the toe pressure sensor (305) is used to collect the pressure at the toe part of the wearer. The second floating structure includes: Toe sensor mounting box (303), the toe sensor mounting box (303) is connected to the side of the toe pressure sensor (305) away from the forefoot connecting piece (302), and the toe sensor mounting box (303) is connected to the forefoot connecting piece (302) through the second positioning screw; the second positioning screw has a third optical axis section and a third thread section, the third optical axis section is used to connect to the toe sensor mounting box (303), and the third thread section will be connected to the bottom of the flexible shoe (202) via the toe sensor mounting box (303), and the toe sensor mounting box (303) can move along the axis direction of the second positioning screw relative to the flexible shoe (202) to eliminate the tension received by the toe sensor mounting box (303) during walking.

7. The exoskeleton bionic ankle-foot system considering the spatio-temporal characteristics of human gait according to claim 6, characterized in that, Two corresponding convex structures (521) are arranged at the end of the foot connecting section (52), and the convex structure (521) includes two semi-circular protrusions arranged from top to bottom; the two semi-circular protrusions are concentrically arranged, and the radius of the semi-circular protrusion located above is smaller than the radius of the other semi-circular protrusion; A first mounting hole (5211) is formed in the convex structure (521), and a connection hole (3022) matching the first mounting hole (5211) is provided at the end of the front sole connecting member (302). The first mounting hole (5211) and the connection hole (3022) cooperate with the metatarsophalangeal joint motion module (4) to movably connect the foot connecting section (52) and the front sole connecting member (302). The metatarsophalangeal joint motion module (4) is used to simulate the flexion and extension freedom degree of the human metatarsophalangeal joint and limit the movement range of the front sole connecting member (302).

8. The exoskeleton bionic ankle-foot system considering the spatio-temporal characteristics of human gait according to claim 7, wherein A second mounting hole (5212) is further formed in the convex structure (521). The second mounting hole (5212) is located below the first mounting hole (5211) and is concentric with the first mounting hole (5211); a limiting protrusion (3023) is provided at the end of the front sole connecting member (302) for connecting with the convex structure (521). The metatarsophalangeal joint motion module (4) includes: A first elastic card (404) and a first pin shaft (401) that cooperate with each other. The connection hole (3022) and the first mounting hole (5211) are connected by the first elastic card (404) and the first pin shaft (401), and the front sole connecting member (302) and the bionic arch mechanism (5) can rotate relative to each other along the axis of the first pin shaft (401) to realize the freedom degree of the wearer's metatarsophalangeal joint; A second pin shaft (405) and a second elastic card (403) that cooperate with each other. The second pin shaft (405) is fixed between the two second mounting holes (5212) by the second elastic card (403). The second pin shaft (405) restricts the movement range of the front sole connecting member (302) through cooperation with the limiting protrusion (3023).

9. The exoskeleton bionic ankle-foot system considering the spatio-temporal characteristics of human gait according to claim 8, characterized in that, A rubber sole (207) and a rubber shoe tip (304) are respectively provided at the bottom of the ankle-foot connecting section (51) and the bottom of the flexible shoe (202); a gasket (402) is provided at the bottom of the bionic arch mechanism (5).

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