Tendon-driven highly coupled humanoid robot leg

Abstract

A tendon-driven highly coupled humanoid robot leg, comprising a first driving device (1), a second driving device (2), a foot plate structure (3), a shank support structure (4), and a thigh support structure (5). A first idler wheel structure (71) and a second idler wheel structure (72) are rotatably provided on a knee joint shaft structure (7), and a first driving wheel structure (61) and a second driving wheel structure (62) are provided on an ankle joint shaft structure (6); and a first tendon rope drive transmission pair (8) is transmittingly connected to the first driving device (1), and is wound on the first idler wheel structure (71) and then sleeved on the first driving wheel structure (61) to form a rotary transmission pair, and a second tendon rope drive transmission pair (9) is transmittingly connected to an output end of the second driving device (2), and is wound on the second idler wheel structure (72) and then sleeved on the second driving wheel structure (62) to form a rotary transmission pair, and the rotation direction of the second idler wheel structure (72) is different from that of the second driving wheel structure (62). Higher peak torque can be achieved, sufficient load capacity of the legs of a robot is provided, energy consumption is lower, the cost is lower, motion inertia is small, and the occupied overall space and mass are lower.

Description

A tendon-driven, highly coupled humanoid robot leg

[0001] Cross-reference to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 2025100468857, filed on January 13, 2025, entitled “A Tendon-Driven Highly Coupled Humanoid Robot Leg”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the technical field of humanoid robots, and more specifically to a highly coupled humanoid robot leg based on tendon actuation. Background Technology

[0004] The legs are the foundation of humanoid robot design and a key factor distinguishing them from other robots, enabling them to perform tasks in complex terrains. Currently, humanoid robot leg structures typically use joint module motors to directly drive the leg joints, or joint module motors to drive the leg joints through a linkage structure. The former suffers from high inertia, while the latter results in abnormally protruding linkage structures, hindering more detailed anthropomorphism, and the exposed linkage structures can cause issues such as safety and lubrication maintenance. Both methods use a conventional drive method where one motor drives one joint. However, the power and peak torque of joint module motors are currently limited for the same mass and volume. If the leg joints are designed to withstand sufficiently high loads, the joint modules will inevitably be bulky and heavy, increasing manufacturing costs. Furthermore, distal leg joint modules will exacerbate the inertia and energy consumption of proximal joint modules.

[0005] Patent document CN118289111A discloses a leg power structure for a humanoid robot and a humanoid robot. The leg power structure includes a stepping drive unit, a thigh assembly, a lower leg assembly, and a foot assembly, all connected sequentially at the waist of the humanoid robot. The stepping drive unit drives the entire leg power structure to swing back and forth. The thigh assembly includes a first thigh and a second thigh, the lower leg assembly includes a lower leg, and the foot assembly includes a foot support. A hip joint drive unit is located on the upper part of the first thigh to drive the entire leg power structure to swing left and right. A first drive unit is located between the first thigh and the second thigh to enable relative circumferential rotation between the first and second thighs. The above technical solution uses a linkage transmission structure, which can reduce the moment of inertia to some extent, but the moment of inertia is still very large, and there are problems with the joint modules being bulky and heavy. As can be seen from the attached drawings in the instruction manual, it uses the method of hollowing out the back of the legs as much as possible in terms of appearance design to reduce the bulky appearance of the legs, but it cannot reduce the weight of the joint modules, manufacturing costs, and energy consumption. Moreover, its flat design inevitably exposes more joint modules, making it difficult to achieve more detailed anthropomorphism. Summary of the Invention

[0006] To address the shortcomings of existing humanoid robot technologies, this disclosure proposes a tendon-driven, highly coupled humanoid robot leg that features a simple structure, achieves higher peak torque, provides sufficient load capacity for the robot leg, consumes less energy during overall movement, has lower manufacturing costs, minimal moment of inertia, and occupies less overall space and mass. This facilitates a better external design and a lighter robot body with enhanced safety features.

[0007] The specific technical solution is as follows:

[0008] A highly coupled humanoid robot leg based on tendon drive includes a first drive device, a second drive device, a foot plate structure, a lower leg support structure, and a thigh support structure. The foot plate structure is rotatably mounted on one end of the lower leg support structure via an ankle joint axis structure, and the thigh support structure is rotatably mounted on the other end of the lower leg support structure via a knee joint axis structure.

[0009] A first idler wheel structure and a second idler wheel structure are rotatably arranged on the knee joint axis structure. The first idler wheel structure and the second idler wheel structure are arranged side by side and independently. A first drive wheel structure and a second drive wheel structure are arranged on the ankle joint axis structure. Both the first drive wheel structure and the second drive wheel structure are fixedly connected to the foot plate structure.

[0010] The output end of the first drive device is connected to a first tendon cable drive transmission pair. This pair is wound around a first idler gear structure and then fitted onto a first drive wheel structure to form a taut rotary transmission pair. The first idler gear structure and the first drive wheel structure rotate in the same direction. The output end of the second drive device is connected to a second tendon cable drive transmission pair. This pair is wound around a second idler gear structure and then fitted onto a second drive wheel structure to form a taut rotary transmission pair. The second idler gear structure and the second drive wheel structure rotate in different directions. Based on the aforementioned description of the transmission relationship, it can be seen that the second idler gear structure and the second drive wheel structure are on the same second... When driven by the same driving device, the rotation directions are opposite; and the terms "first" and "second" described here have no specific meaning, but are merely a distinguishing description. Therefore, it is also possible that the first idler wheel structure and the first driving wheel structure rotate in opposite directions under the drive of the first driving device. That is, when the first idler wheel structure, the second idler wheel structure, the first driving wheel structure, and the second driving wheel structure are driven in the same driving direction, the rotation direction of one of the wheels is different from the rotation direction of the other three wheels. This is because only one set of idler wheel structures rotates in the opposite direction to the driving wheel structure, while the other set of idler wheel structures rotates in the same direction as the driving wheel structure, and must necessarily have the same rotation direction as one of the idler wheel structure and the driving wheel structure that rotate in the opposite direction.

[0011] Optionally, both the output ends of the first and second drive devices are provided with sprockets or synchronous belt pulleys. Other transmission structures that do not slip and are easy to bend and connect ropes are also acceptable. The first idler wheel structure, the first drive wheel structure, the second idler wheel structure, and the second drive wheel structure are winding pulleys. The first tendon cable drive transmission pair and the second tendon cable drive transmission pair are both composed of a chain or synchronous belt and non-elastic ropes connected to both ends of the chain or synchronous belt. The chain or synchronous belt cooperates with the sprocket or synchronous belt pulley, and the non-elastic ropes are sleeved on the corresponding winding pulleys to form a rotary transmission system.

[0012] Optionally, non-elastic rope A and non-elastic rope B are respectively connected to both ends of the chain or timing belt. The non-elastic rope A and non-elastic rope B are respectively secured to the foot plate structure or the corresponding first drive wheel structure and second drive wheel structure, and the non-elastic rope A and non-elastic rope B of the second tendon cable drive pair are arranged in a cross-string configuration between the second idler wheel structure and the second drive wheel structure.

[0013] Optionally, the output ends of the first drive device and the second drive device are respectively provided with a first sprocket and a second sprocket. The first tendon cable drive transmission pair is composed of a first chain and a first metal cable A and a first metal cable B connected to both ends of the first chain. The first chain cooperates with the first sprocket. The first metal cable A and the first metal cable B are wound around the first idler wheel structure and then sleeved on the first drive wheel structure to form a tight rotary transmission system.

[0014] The second tendon cable drive transmission pair consists of a second chain and a second metal cable A and a second metal cable B connected to both ends of the second chain. The second sprocket cooperates with the second chain. The second metal cable A and the second metal cable B are wound around the second idler wheel structure and then sleeved on the second drive wheel structure to form a tight rotary transmission system. The second metal cable A and the second metal cable B are arranged in a cross-wire configuration between the second idler wheel structure and the second drive wheel structure.

[0015] Optionally, a joint frame mounting support is fixedly installed on the ankle joint axis structure, configured as a foot plate structure, and the first drive wheel structure and the second drive wheel structure are respectively arranged on both sides of the joint frame mounting support.

[0016] Optionally, a set of locking slots is provided on both sides of the joint frame mounting support. Each set of locking slots consists of a fixing slot and an adjusting slot. The fixing slot and the adjusting slot are respectively located at both ends of the joint frame mounting support and correspond to the positions of the first drive wheel structure or the second drive wheel structure.

[0017] A fixing clip structure is provided at the end of the first metal cable A and the second metal cable A, and the clip structure cooperates with the corresponding fixing slot; a tension adjustment clip structure is provided at the end of the second metal cable B and the first metal cable B, and the tension adjustment clip structure cooperates with the corresponding adjustment hole.

[0018] Optionally, the first driving device and the second driving device are motor modules.

[0019] Optionally, the transmission ratio between the first drive device, the first idler wheel structure and the first drive wheel structure is the same as the transmission ratio between the second drive device, the second idler wheel structure and the second drive wheel structure. This makes the structural design more regular and makes it easier to accurately calculate the motion control mode for subsequent combined drives.

[0020] Optionally, both the first drive device and the second drive device are mounted on the thigh support structure, and the first drive device and the second drive device are arranged opposite to each other and have the same power parameters. This makes the structural design more regular and makes it easier to accurately calculate the motion control mode for subsequent combined drives.

[0021] Optionally, the ankle joint axis structure is rotatably mounted on the end of the calf support structure via a bearing structure, the foot plate structure is fixedly mounted on the ankle joint axis structure, and the first drive wheel structure, the second drive wheel structure, the ankle joint axis structure, and the foot plate structure are all fixedly connected.

[0022] The beneficial effects of this disclosure are as follows: By coupling the transmission mechanism connected by the dual drive devices, the kinetic energy distribution and combination can be achieved. This allows the dual drive devices to control the independent or combined movement of the two joints in different rotational combinations, achieving the same effect as two single drives independently controlling two joints. Specifically, the two joints can move individually or simultaneously in combination, and their respective movement speeds can be the same or different. Furthermore, the tendon drive reduces the moment of inertia, further saving the space and mass occupied by the distal joint module, resulting in extremely small moment of inertia, requiring less driving force and energy consumption, facilitating the selection of a better appearance design, and also contributing to the robot's body safety.

[0023] With no dead zones in the aforementioned transmission combination control motion combination, this solution can control the movement of a single joint independently through the combination of dual drive devices, thus achieving higher peak torque and providing the robot's legs with higher load capacity. Furthermore, the transmission mechanisms connected by the dual drive devices independently constrain the movement of the two joints. In the event of a failure in one drive device or transmission mechanism, the other drive device and transmission mechanism can still maintain the stability of the two joints, thus allowing for safer waiting for maintenance and repair, resulting in better structural stability.

[0024] Furthermore, under the same load conditions, the power parameters of the two drive devices required for control are relatively small, and their size and mass are generally smaller. Moreover, when full kinetic energy is not required, the energy distribution is equivalent to two small-power drive devices independently controlling two independent joints, thus saving more energy. Since the two independent joints themselves require two drive devices to drive them, to achieve greater peak kinetic energy and torque, larger drive devices are usually required. However, this transmission scheme overcomes this problem. Theoretically, with the requirement of doubling the peak torque and kinetic energy, this transmission scheme does not require a larger power drive device, thus achieving lower manufacturing costs and lower overall space and mass. Attached Figure Description

[0025] Figure 1 is a schematic diagram of the overall structure of the robot's two legs.

[0026] Figure 2 is a schematic diagram of the overall structure of this disclosure.

[0027] Figure 3 is a schematic diagram of the cross-sectional structure of the knee joint axis in this disclosure.

[0028] Figure 4 is a schematic diagram of the cross-sectional structure of the ankle joint axis in this disclosure.

[0029] Figure 5 is a schematic diagram of the first tendon chord drive transmission pair and the second tendon chord drive transmission pair in this disclosure.

[0030] Figure 6 is a schematic diagram of the installation of the first tendon chord drive transmission pair and the second tendon chord drive transmission pair in this disclosure.

[0031] Figure 7 is a side view of the ankle joint axial structure in this disclosure.

[0032] Explanation of reference numerals in the attached drawings: First drive device 1; Second drive device 2; Foot plate structure 3; Lower leg support structure 4; Thigh support structure 5; Ankle joint axis structure 6; Knee joint axis structure 7; First tendon cable drive transmission pair 8; Second tendon cable drive transmission pair 9; First sprocket 11; Second sprocket 21; First drive wheel structure 61; Second drive wheel structure 62; Joint frame mounting support 63; Fixed slot 601; Adjusting hole 602; First idler wheel structure 71; Second idler wheel structure 72; First chain 81; First metal cable A 82; First metal cable B 83; Fixed head structure 801; Tension adjustment head structure 802; Second chain 91; Second metal cable A 92; Second metal cable B 93. Detailed Implementation

[0033] The preferred embodiments of this disclosure will now be described in detail with reference to the accompanying drawings, so that the advantages and features of this disclosure can be more easily understood by those skilled in the art, thereby providing a clearer and more definite definition of the scope of protection of this disclosure.

[0034] In the description of this disclosure, it should be noted that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure.

[0035] In the description of this disclosure, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can be a direct connection or a connection through an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0036] Example:

[0037] As shown in Figures 1, 2, 3, 4, 5, 6, and 7: A highly coupled humanoid robot leg based on tendon drive is provided with a first drive device 1, a second drive device 2, a foot plate structure 3, a lower leg support structure 4, and a thigh support structure 5. The first drive device 1 and the second drive device 2 are motor modules, but other types such as hydraulic motors or pneumatic motors are also possible. Motor modules are the most commonly used in the field of robotics, but theoretically, any method that is rotary drive or converted into rotary drive through a transmission group is acceptable. The foot plate structure 3 is rotatably mounted on one end of the lower leg support structure 4 through an ankle joint axis structure 6, and the thigh support structure 5 is rotatably mounted on the other end of the lower leg support structure 4 through a knee joint axis structure 7.

[0038] A first idler wheel structure 71 and a second idler wheel structure 72 are rotatably arranged on the knee joint axis structure 7. The first idler wheel structure 71 and the second idler wheel structure 72 are arranged side by side and independently. A first drive wheel structure 61 and a second drive wheel structure 62 are arranged on the ankle joint axis structure 6. Both the first drive wheel structure 61 and the second drive wheel structure 62 are fixedly connected to the foot plate structure 3.

[0039] A first tendon cable drive pair 8 is connected to the output end of the first drive device 1. The first tendon cable drive pair 8 is wound around the first idler gear structure 71 and then fitted onto the first drive wheel structure 61 to form a tight rotary drive pair. The first idler gear structure 71 and the first drive wheel structure 61 rotate in the same direction. A second tendon cable drive pair 9 is connected to the output end of the second drive device 2. The second tendon cable drive pair 9 is wound around the second idler gear structure 72 and then fitted onto the second drive wheel structure 62 to form a tight rotary drive pair. The second idler gear structure 72 and the second drive wheel structure 62 rotate in different directions, i.e., opposite directions. Based on the aforementioned description of the transmission relationship, it can be seen that the second idler gear structure 72 and the second drive wheel structure 62 are... Under the same driving direction of the same second driving device 2, the rotation directions are opposite; and the "first" and "second" described here have no specific reference, but are only a distinguishing description. Therefore, it is also possible that the first idler wheel structure 71 and the first driving wheel structure 61 rotate in opposite directions under the driving of the first driving device 1. That is, under the same driving direction, the rotation direction of one of the first idler wheel structure 71, the second idler wheel structure 72, the first driving wheel structure 61 and the second driving wheel structure 62 is different from the rotation direction of the other three wheels. Since only one set of idler wheel structures rotates in the opposite direction to the driving wheel structure, and the other set of idler wheel structures rotates in the same direction as the driving wheel structure, and must be the same as the rotation direction of one of the idler wheel structure and the driving wheel structure that rotates in the opposite direction.

[0040] Specifically: the output ends of the first drive device 1 and the second drive device 2 are respectively provided with a first sprocket 11 and a second sprocket 21, or the output ends of the first drive device 1 and the second drive device 2 are respectively provided with synchronous belt pulleys or other structures that can be easily bent and accurately transmit power. The first idler gear structure 71, the first drive wheel structure 61, the second idler gear structure 72 and the second drive wheel structure 62 are winding pulleys. The first tendon cable drive transmission pair 8 is composed of a first chain 81 and a first metal cable A82 and a first metal cable B83 connected to both ends of the first chain 81, or the first tendon cable drive transmission pair 8 and the second tendon cable drive transmission pair 9 are both composed of a chain or a synchronous belt and a non-elastic rope A connected to both ends of the chain or synchronous belt. The system consists of a non-elastic rope A and a non-elastic rope B. While the non-elastic rope A and non-elastic rope B can be the same non-elastic rope, a single non-elastic rope is difficult to tighten during the formation of a taut rotary transmission pair. Therefore, the non-elastic rope A and non-elastic rope B are separately configured. The ends of the non-elastic rope A and non-elastic rope B are respectively secured to the foot plate structure 3 or the corresponding first drive wheel structure 61 and second drive wheel structure 62 to achieve a taut rotary transmission pair. Furthermore, the non-elastic rope A and non-elastic rope B of the second tendon cable drive transmission pair 9 are cross-wired between the second idler wheel structure 72 and the second drive wheel structure 62 to achieve different rotation directions under the same drive. The non-elastic ropes include non-metallic ropes and metal cables; any rope with sufficient load-bearing capacity and low deformation is acceptable. However, generally acceptable and low-cost metal cables, more specifically steel cables, chains, or synchronous belts, are suitable for cooperation with sprockets or synchronous pulleys. The non-elastic ropes are looped around the corresponding winding reels to form the rotary transmission system.

[0041] Specifically, the first chain 81 cooperates with the first sprocket 11, and the first metal cable A82 and the first metal cable B83 are wound around the first idler wheel structure 71 and then sleeved on the first drive wheel structure 61 to form a tight rotary transmission system.

[0042] The second tendon cable drive transmission pair 9 consists of a second chain 91 and second metal cables A92 and B93 connected to both ends of the second chain 91, respectively. The second sprocket 21 cooperates with the second chain 91. The second metal cables A92 and B93 are wound around the second idler wheel structure 72 and then sleeved on the second drive wheel structure 62 to form a taut rotary transmission system. The second metal cables A92 and B93 are arranged in a cross-wire configuration between the second idler wheel structure 72 and the second drive wheel structure 62. This is to meet the requirement that the second idler wheel structure 72 and the second drive wheel structure 62 rotate in opposite directions. The whole system is a transmission scheme that combines rigidity and flexibility. It has the precision of rigid transmission and the ease of maintenance and installation of flexible transmission, as well as the characteristics of small space and weight. Furthermore, the distal joint does not have the load of the motor module and has a very small moment of inertia. Therefore, the required driving force is also less than that required by other robot legs.

[0043] Furthermore, a joint bracket mounting support 63 is fixedly installed on the ankle joint axis structure 6, configured to mount the foot plate structure 3. The first drive wheel structure 61 and the second drive wheel structure 62 are respectively located on both sides of the joint bracket mounting support 63. The foot plate structure 3 is mounted through the joint bracket mounting support 63, which facilitates disassembly, replacement, and maintenance of the foot plate structure 3 after wear, and also allows for the expansion of lateral joints through the joint bracket mounting support 63. The ankle joint axis structure 6 is rotatably mounted on the end of the lower leg support structure 4 via a bearing structure. The foot plate structure 3 is fixedly mounted on the ankle joint axis structure 6, and the first drive wheel structure 61, the second drive wheel structure 62, the ankle joint axis structure 6, and the foot plate structure 3 are all fixedly connected. This makes the joint of the ankle joint axis structure 6 more stable and less prone to vibration and loosening. The same principle applies to the knee joint axis structure 7.

[0044] Furthermore, a set of locking slots is provided on both sides of the joint frame mounting support 63. The set of locking slots consists of a fixed locking slot 601 and an adjusting locking hole 602. The fixed locking slot 601 and the adjusting locking hole 602 are respectively provided at both ends of the joint frame mounting support 63 and correspond to the positions of the first drive wheel structure 61 or the second drive wheel structure 62.

[0045] A fixing clip structure 801 is provided at the end of the first metal cable A82 and the second metal cable A92, and the clip structure 801 cooperates with the corresponding fixing slot 601; a tension adjustment clip structure 802 is provided at the end of the second metal cable B93 and the first metal cable B83, and the tension adjustment clip structure 802 cooperates with the corresponding adjustment hole 602, thereby facilitating the formation of a tensioned rotary transmission pair between the first metal cable A82 and the first metal cable B83 or between the second metal cable A92 and the second metal cable B93.

[0046] Furthermore, the transmission ratio between the first drive device 1, the first idler wheel structure 71 and the first drive wheel structure 61 is the same as the transmission ratio between the second drive device 2, the second idler wheel structure 72 and the second drive wheel structure 62; the first drive device 1 and the second drive device 2 are both mounted on the thigh support structure 5, and the first drive device 1 and the second drive device 2 are arranged opposite to each other, and their power parameters are the same; this facilitates a more regular structural design and makes it easier to accurately calculate the motion control mode for subsequent combined drives.

[0047] Then, taking the case where the rotation directions of the first idler wheel structure 71 and the first drive wheel structure 61 are the same as the rotation direction of the second idler wheel structure 72, but the rotation directions of the second idler wheel structure 72 and the second drive wheel structure 62 are different, as an example, this is the key point that the transmission mechanism of this scheme can perform kinetic energy distribution and control the independent movement of the two joints. Since the first idler wheel structure 71 and the second idler wheel structure 72 are free to rotate, the specific motion control scheme and principle are as follows:

[0048] (i) Only the ankle joint axis structure 6 rotates: This is achieved by the first drive device 1 and the second drive device 2 rotating in opposite directions at the same speed. At this time, the first drive wheel structure 61 and the second drive wheel structure 62 at the ankle joint axis structure 6 receive two transmission forces in the same direction and at the same speed (at this time, the magnitude of the transmission torque is also the same. When the transmission ratio or the power parameters of the drive motor are different, the magnitude of the torque is different. It would be more complicated to calculate the same speed by superimposing them. Moreover, since the positions of the first drive wheel structure 61 and the second drive wheel structure 62 do not overlap, it may cause more complicated situations such as deflection force. Therefore, this method is generally not used). The two torques with the same speed act on the ankle joint axis structure 6 at the same time. Therefore, only the ankle joint axis structure 6 rotates to output the kinetic energy of the combination of the first drive device 1 and the second drive device 2. Meanwhile, the first idler wheel structure 71 and the second idler wheel structure 72 at the knee joint axis structure 7 only act as intermediate transmission structures and rotate freely. At this time, the first idler wheel structure 71 and the second idler wheel structure 72 rotate in opposite directions and at the same speed.

[0049] (II) Rotation of only the knee joint axis structure 7: This is achieved by the first drive device 1 and the second drive device 2 rotating in the same direction and at the same speed. At this time, the first drive wheel structure 61 and the second drive wheel structure 62 at the ankle joint axis structure 6 receive two mutually canceling and opposing transmission forces, that is, opposite in direction and the same speed (at this time, the magnitude of the transmission torque is also the same. Although it is not necessarily required to be the same, if the torque difference is too large, in addition to the above problems, the ankle joint axis structure 6 may also experience torque-counteracting vibration, making the movement inaccurate and generating unnecessary energy consumption. The opposing and canceling transmission forces within a system as a whole do not do work externally, and therefore do not consume energy). Therefore, the ankle joint axis structure 6 cannot move. Under this premise, the first idler wheel structure 71 and the second idler wheel structure 72 cannot act as intermediate transmission free wheels. Therefore, the first idler wheel structure 71 and the second idler wheel structure 72 are locked as a whole relative to the fixed installation part of the knee joint axis structure 7 and cannot rotate (because the knee joint axis structure 7 includes two opposing and opposing transmission forces). For the rotating parts, both the first idler gear structure 71 and the second idler gear structure 72 are installed on one of them. This applies whether the shaft includes two rotating parts, or whether the shaft rotates with the end of the lower leg support structure 4 or the thigh support structure 5 and is then fixed to another joint frame. (In this context, "joint shaft structure" broadly refers to the entire rotatable joint and does not narrowly refer to a specific shaft.) The driving strokes of the first drive device 1 and the second drive device 2 are in the same direction and at the same speed at the knee joint shaft structure 7 (if the transmission ratio and drive parameters are different, the driving speed also needs to be adjusted to achieve the same direction and speed at this point). Therefore, the kinetic energy of the first drive device 1 and the second drive device 2 can only be output through the rotation of the knee joint shaft structure 7. At this time, the components between the foot plate structure 3 and the lower leg support structure 4 are equivalent to a whole system. The drive device pulls the knee joint shaft structure 7, which is connected by the idler gear structure as torque, through the tendon cable drive pair to rotate, so as to realize the movement of the whole system of the foot plate structure 3 and the lower leg support structure 4 relative to the thigh support structure.

[0050] (III) The ankle joint axis structure 6 and the knee joint axis structure 7 rotate simultaneously and in combination: This is achieved by the different rotation speeds of the first drive device 1 and the second drive device 2. The rotation in the same direction or in opposite directions, and which of the first drive device 1 and the second drive device 2 has a higher speed, determines the combination of the rotation directions of the ankle joint axis structure 6 and the knee joint axis structure 7.

[0051] In general, the rotational speeds of the first joint axis structure 6 and the second joint axis structure 7 are calculated as follows:

[0052] Assume that the rotational speeds of the first drive device 1 and the second drive device 2 are M1 and M2, respectively;

[0053] The transmission ratio between the first drive device 1 and the second drive device 2 and the first idler wheel structure 71 and the second idler wheel structure 72 is I2;

[0054] The transmission ratio between the first driving device 1 and the second driving device 2 and the first driving wheel structure 61 and the second driving wheel structure 62 is I1, so it can be concluded that:

[0055] Rotation speed of the first joint axis structure 6 When the first drive device 1 and the second drive device 2 rotate in the same direction and at the same speed, then M1-M2=0, and thus V1=0;

[0056] Rotation speed of the second joint axis structure 7 When the first driving device 1 and the second driving device 2 rotate in opposite directions and at the same speed, then M1+M2=0, and thus V2=0.

[0057] Its performance is as follows: By coupling the transmission mechanism connected by dual drive devices to distribute and combine kinetic energy, it is possible to control the independent movement of the two joints under different states. That is, it can achieve the same effect as two single drives independently controlling two joints. Specifically, the two joints can move individually or simultaneously in combination, and their respective movement speeds can be the same or different. Furthermore, the tendon drive reduces the moment of inertia, further saving the space and mass occupied by the distal joint module, resulting in extremely small moment of inertia, requiring less driving force and energy consumption, and making it easier to choose a better appearance design, which is also beneficial to the safety of the robot body.

[0058] With no dead zones in the aforementioned transmission combination control motion combination, this solution can control the movement of a single joint independently through the combination of dual drive devices, thus achieving higher peak torque and providing the robot's legs with higher load capacity. Furthermore, the transmission mechanisms connected by the dual drive devices independently constrain the movement of the two joints. In the event of a failure in one drive device or transmission mechanism, the other drive device and transmission mechanism can still maintain the stability of the two joints, thus allowing for safer waiting for maintenance and repair, resulting in better structural stability.

[0059] Furthermore, under the same load conditions, the power parameters of the two drive devices required for control are relatively small, and their size and mass are generally smaller. Moreover, when full kinetic energy is not required, the energy distribution is equivalent to two small-power drive devices independently controlling two independent joints, thus saving more energy. Since the two independent joints themselves require two drive devices to drive them, to achieve greater peak kinetic energy and torque, larger drive devices are usually required. However, this transmission scheme overcomes this problem. Theoretically, with the requirement of doubling the peak torque and kinetic energy, this transmission scheme does not require a larger power drive device, thus achieving lower manufacturing costs and lower overall space and mass.

[0060] Although embodiments of the present disclosure have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined by the appended claims. Industrial applicability

[0061] In summary, this disclosure provides a tendon-driven, highly coupled humanoid robot leg that can achieve higher peak torque, provide sufficient load capacity for the robot leg, and has lower energy consumption, lower cost, smaller moment of inertia, and lower overall space and mass.

Claims

1. A highly coupled humanoid robot leg based on tendon actuation, characterized in that: It includes a first drive device (1), a second drive device (2), a foot plate structure (3), a lower leg support structure (4) and a thigh support structure (5). The foot plate structure (3) is rotatably mounted on one end of the lower leg support structure (4) via an ankle joint axis structure (6), and the thigh support structure (5) is rotatably mounted on the other end of the lower leg support structure (4) via a knee joint axis structure (7). A first idler wheel structure (71) and a second idler wheel structure (72) are rotatably disposed on the knee joint axis structure (7). The first idler wheel structure (71) and the second idler wheel structure (72) are arranged side by side and independently. A first drive wheel structure (61) and a second drive wheel structure (62) are disposed on the ankle joint axis structure (6). Both the first drive wheel structure (61) and the second drive wheel structure (62) are fixedly connected to the foot plate structure (3). The first drive device (1) is connected to a first tendon cable drive transmission pair (8) at its output end. The first tendon cable drive transmission pair (8) is wound around the first idler wheel structure (71) and then sleeved on the first drive wheel structure (61) to form a tight rotary transmission pair. The second drive device (2) is connected to a second tendon cable drive transmission pair (9) at its output end. The second tendon cable drive transmission pair (9) is wound around the second idler wheel structure (72) and then sleeved on the second drive wheel structure (62) to form a tight rotary transmission pair. The rotation directions of the second idler wheel structure (72) and the second drive wheel structure (62) are different.

2. The tendon-driven, highly coupled humanoid robot leg according to claim 1, characterized in that: The output ends of the first drive device (1) and the second drive device (2) are both provided with sprockets or synchronous belt pulleys. The first idler wheel structure (71), the first drive wheel structure (61), the second idler wheel structure (72) and the second drive wheel structure (62) are winding pulleys. The first tendon rope drive transmission pair (8) and the second tendon rope drive transmission pair (9) are both composed of chains or synchronous belts and non-elastic ropes connected to both ends of the chains or synchronous belts. The chains or synchronous belts cooperate with the sprockets or synchronous belt pulleys. The non-elastic ropes are sleeved on the corresponding winding pulleys to form a rotary transmission system.

3. The tendon-driven, highly coupled humanoid robot leg according to claim 2, characterized in that: Non-elastic rope A and non-elastic rope B are respectively connected to both ends of the chain or timing belt. The non-elastic rope A and non-elastic rope B are respectively locked on the foot plate structure (3) or the corresponding first drive wheel structure (61) and second drive wheel structure (62). The non-elastic rope A and non-elastic rope B of the second tendon cable drive pair (9) are arranged to cross between the second idler wheel structure (72) and the second drive wheel structure (62).

4. The tendon-driven, highly coupled humanoid robot leg according to any one of claims 1-3, characterized in that: The output ends of the first drive device (1) and the second drive device (2) are respectively provided with a first sprocket (11) and a second sprocket (21). The first tendon cable drive transmission pair (8) is composed of a first chain (81) and a first metal cable A (82) and a first metal cable B (83) connected to both ends of the first chain (81). The first chain (81) cooperates with the first sprocket (11). The first metal cable A (82) and the first metal cable B (83) are wound around the first idler structure (71) and then sleeved on the first drive wheel structure (61) to form a tight rotary transmission system. The second tendon cable drive pair (9) consists of a second chain (91) and a second metal cable A (92) and a second metal cable B (93) connected to both ends of the second chain (91). The second sprocket (21) cooperates with the second chain (91). The second metal cable A (92) and the second metal cable B (93) are wound around the second idler wheel structure (72) and then sleeved on the second drive wheel structure (62) to form a tight rotary transmission system. The second metal cable A (92) and the second metal cable B (93) are arranged in a cross-wire configuration between the second idler wheel structure (72) and the second drive wheel structure (62).

5. The tendon-driven, highly coupled humanoid robot leg according to claim 4, characterized in that: A joint frame mounting support (63) is fixedly installed on the ankle joint axis structure (6) and configured to mount the foot plate structure (3). The first drive wheel structure (61) and the second drive wheel structure (62) are respectively located on both sides of the joint frame mounting support (63).

6. The tendon-driven, highly coupled humanoid robot leg according to claim 5, characterized in that: A set of locking slots is provided on both sides of the joint frame mounting support (63). The set of locking slots consists of a fixed locking slot and an adjusting locking hole. The fixed locking slot and the adjusting locking hole are respectively located at the two ends of the joint frame mounting support (63) and correspond to the positions of the first drive wheel structure (61) or the second drive wheel structure (62). A fixing clip structure is provided at the end of the first metal cable A (82) and the second metal cable A (92), and the clip structure cooperates with the corresponding fixing slot; a tension adjustment clip structure is provided at the end of the second metal cable B (93) and the first metal cable B (83), and the tension adjustment clip structure cooperates with the corresponding adjustment hole.

7. The tendon-driven, highly coupled humanoid robot leg according to any one of claims 1-6, characterized in that: The first drive device (1) and the second drive device (2) are motor modules.

8. The tendon-driven, highly coupled humanoid robot leg according to any one of claims 1-7, characterized in that: The transmission ratio between the first drive device (1), the first idler gear structure (71) and the first drive wheel structure (61) is the same as the transmission ratio between the second drive device (2), the second idler gear structure (72) and the second drive wheel structure (62).

9. The tendon-driven, highly coupled humanoid robot leg according to claim 8, characterized in that: The first drive device (1) and the second drive device (2) are both installed at the end of the thigh support structure (5), and the first drive device (1) and the second drive device (2) are arranged opposite to each other.

10. The tendon-driven, highly coupled humanoid robot leg according to any one of claims 1-9, characterized in that: The ankle joint shaft structure (6) is rotatably mounted on the end of the calf support structure (4) via a bearing structure, and the foot plate structure (3) is fixedly mounted on the ankle joint shaft structure (6). The first drive wheel structure (61), the second drive wheel structure (62), the ankle joint shaft structure (6) and the foot plate structure (3) are all fixedly connected.

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