A foot-type robot

Abstract

The application discloses a kind of foot type robots, for reducing upper extremity end support dependence while improving rising speed and rising stability.The foot type robot provided by the application comprises: a torso, the torso includes upper torso and crotch, the upper torso is rotatably connected with the crotch;Head, two upper limbs, two lower limbs and corresponding limb ends connected with the torso respectively, wherein the two lower limbs are connected with the crotch respectively;At least one processor;And at least one storage medium, the at least one storage medium stores instructions, the instructions are executed by the at least one processor to make the foot type robot: in response to rising trigger instruction, execute rising action sequence, rising action sequence includes initial support stage and rising stage;Initial support stage includes: control the foot type robot enters initial support state;Rising stage includes: control the center of mass of the foot type robot rises.

Description

Technical Field

[0001] This application relates to the field of robotics, and more particularly to a legged robot. Background Technology

[0002] During walking, turning, or operation, legged robots may become unstable and fall due to external collisions, changes in ground conditions, or control errors. If a robot cannot quickly return to a standing position after a fall, it will affect the execution of subsequent tasks. Therefore, the ability to automatically get up after a fall is of great significance for the continuous operation of legged robots.

[0003] In related recovery methods, to gain support in a low-positioned posture, robots often need to make contact with the contact surface using their upper limbs (hands), and then use the upper limbs to apply supporting force to the contact surface to lift the torso or adjust the posture. These methods rely heavily on upper limb support, and the upper limbs typically perform grasping, sensing, or interaction functions, making their structure relatively complex. When the upper limbs bear the weight of the robot or experience contact impact during the recovery process, they are prone to wear or damage, which can affect the robot's subsequent operations. Furthermore, the robot's fall posture is unpredictable; when the upper limbs are trapped, arm movement is restricted, or the contact surface is not conducive to stable support for the upper limbs, the recovery process relying on upper limb support is easily affected. Summary of the Invention

[0004] This application provides a legged robot that improves standing speed and stability while reducing reliance on upper limb end support.

[0005] This application provides a legged robot, comprising:

[0006] The torso includes an upper torso and hips, with the upper torso and hips rotatably connected; The head, two upper limbs, two lower limbs, and corresponding limb ends are respectively connected to the torso, wherein the two lower limbs are respectively connected to the hip. At least one processor; and, At least one storage medium storing instructions that, when executed by the at least one processor, cause the legged robot to: In response to a stand-up trigger command, a stand-up action sequence is executed, the stand-up action sequence including an initial support phase and a stand-up phase; wherein... The initial support phase includes: controlling the legged robot to enter an initial support state, in which the minimum distance between the head and the contact surface is a first distance, the minimum distance between the hip and the contact surface is a second distance, the sum of the length of the torso and the second distance is a third distance, the ratio of the first distance to the third distance is greater than or equal to 0.65, there are at least two support points between the first lower limb and the contact surface, there is at least one support point between the second lower limb and the contact surface, the second lower limb establishes support contact with the contact surface at least through a first support part, the first surface distance between the first support part and the hip is less than the second surface distance between the lower limb end of the second lower limb and the hip, the knee joint angle of the first lower limb is 30° to 120°, the knee joint angle of the second lower limb is 45° to 150°, and the ratio of the minimum distance between the knee joints of the two lower limbs to the thigh length of the first lower limb is greater than or equal to 1. The standing phase includes: controlling the center of gravity of the legged robot to rise; during the rise of the center of gravity: controlling the upper torso to rotate relative to the hip, wherein the rotation angle of the upper torso relative to the hip is greater than or equal to 20°; controlling the knee joint of the first lower limb to rise away from the contact surface, wherein during the rise of the knee joint of the first lower limb away from the contact surface, the lower limb end of the first lower limb makes support contact with the contact surface; controlling the first support part of the second lower limb to disengage from the contact surface, and controlling the lower limb end of the second lower limb to make support contact with the contact surface.

[0007] As can be seen from the above technical solutions, this application has the following advantages: When executing a standing-up sequence, the legged robot first enters an initial support state. In this state, by ensuring the ratio of the first to the third distance between the head and the contact surface is greater than or equal to 0.65, the robot already has a certain degree of upper body elevation before standing up, reducing the required upper torso movement during subsequent standing. Simultaneously, there are at least two support points between the first lower limb and the contact surface, and at least one support point between the second lower limb and the contact surface. This allows the robot to form a multi-point support base with its two lower limbs in a low-position posture, thus achieving a relatively stable support state in the initial stage of standing up. The second lower limb establishes support contact with the contact surface through the first support part, and the distance between the first support part and the hip on the first surface is less than the distance between the lower limb tip and the hip on the second surface. This allows the second lower limb to initially participate in low-position support through a part relatively close to the hip, and then transition to support at the lower limb tip during standing up, facilitating force generation and controlling the overall center of gravity rise during subsequent standing. The knee joint angles of the first and second lower limbs are within their respective ranges, and the distance between the knee joints of the two lower limbs matches the thigh length of the first lower limb, allowing the two lower limbs to form a laterally spread supporting posture on the contact surface. This posture helps to expand the low-level support range of the robot, giving it a more stable posture base, and facilitating the control of the lower limb joint force exertion during subsequent standing up, thus controlling the overall center of gravity rise.

[0008] During the standing-up phase, the center of gravity of the legged robot is controlled to rise. During this rise, the upper torso rotates relative to the hips at an angle greater than or equal to 20°, generating an upward impulse that assists in the upward movement of the robot's center of gravity. Further, the knee joint of the first lower limb is raised away from the contact surface, maintaining contact between the lower limb's distal end and the contact surface during this raising process. This allows the first lower limb to gradually transition from low-level multi-point support to distal end support. Simultaneously, the support area of ​​the second lower limb shifts from the first support area to the distal end, completing the transition from near-hip support to distal end support. This continuous switching of support states reduces reliance on distal end support during standing, lowering the risk of pressure injury to the distal end and shortening the time required to recover from a fallen posture to a bipedal support state, thus increasing the speed of standing up. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 A schematic diagram of the overall structure of a humanoid robot provided as an example of a legged robot for this application; Figure 2 A schematic diagram of the stages of an embodiment of the standing motion sequence of the legged robot provided in this application; Figure 3 A schematic diagram of a support state of the legged robot provided in this application in its initial support state; Figure 4 A schematic diagram of a support state of the legged robot provided in this application at a certain moment during the standing-up phase; Figure 5-A , Figure 5-B and Figure 5-C A schematic diagram illustrating the process by which a legged robot provided in this application enters an initial support state based on a supine posture; Figure 6-A and Figure 6-B This is a schematic diagram illustrating the process by which a legged robot, as provided in this application, enters an initial support state based on a prone posture. Detailed Implementation

[0011] This application provides a legged robot that improves standing speed and stability while reducing reliance on upper limb end support.

[0012] The legged robot provided in this application includes a torso, a head, two upper limbs, two lower limbs, at least one processor, and at least one storage medium. In some embodiments, the legged robot can be a humanoid robot, which is a specific implementation of the legged robot. For ease of description, the following description mainly uses a humanoid robot as an example. Please refer to... Figure 1 The torso 3 includes an upper torso 31 and a hip 32, which are rotatably connected via a power module 33. The head 4 is connected to the upper torso 31, the two upper limbs 1 are connected to the upper torso 31 respectively, and the two lower limbs 2 are connected to the hip 32 respectively. For ease of description, the two upper limbs can be referred to as the first upper limb and the second upper limb, and the two lower limbs can be referred to as the first lower limb and the second lower limb. It should be noted that the terms first upper limb, second upper limb, first lower limb, and second lower limb are only used to distinguish different limb structures and do not constitute a limitation on specific left and right positions.

[0013] Each upper limb includes an end effector for establishing supporting contact with a contact surface. Each upper limb may also include an upper arm and a forearm. The upper arm is connected to the upper torso, and the forearm is connected to the end effector. The upper arm and forearm are connected via an elbow joint. Each lower limb includes an end effector for establishing supporting contact with a contact surface. Each lower limb may also include a thigh and a lower leg. The thigh is connected to the hip, and the lower leg is connected to the end effector. The thigh and lower leg are connected via a knee joint, enabling the lower limb to adjust its posture between different support states. It should be noted that the contact surface can be the ground, platform surface, sports field surface, cushioning surface, or other bearing surface that can provide support for the legged robot; the end effector of the upper limb can be a hand, a robotic hand, or other end structure that can establish supporting contact with the contact surface; the end effector of the lower limb can be a foot, a foot actuator, or other end structure that can establish supporting contact with the contact surface. This application does not limit the scope of these claims.

[0014] It should be noted that, in the embodiments of this application, "contact" refers to the state in which the limbs, torso, or other body parts of the legged robot are in physical contact with the contact surface; "supporting contact" refers to the state in which the above-mentioned contact provides support to the legged robot, enabling the corresponding part to bear part of the load from the body. Specifically, when a part of the legged robot only makes slight contact, rubbing, or non-load-bearing contact with the contact surface, that part can be understood as having ordinary contact with the contact surface; when there is a contact between that part and the contact surface that can bear the weight of the body or participate in posture stability, that part can be understood as establishing supporting contact with the contact surface. Whether supporting contact is established can be determined by force sensors, tactile sensors, joint torque, motor current, contact pressure distribution, or posture changes.

[0015] At least one of the aforementioned storage media stores instructions that, when executed by at least one processor, control the coordinated operation of the various drive components of the legged robot to enable the legged robot to respond to a stand-up command and execute a stand-up action sequence. The stand-up action sequence includes an initial support phase and a stand-up phase, with the initial support phase preceding the stand-up phase. The stand-up command can be input by a user or automatically generated by the legged robot based on its own state or motion planning results.

[0016] Please see Figure 2 , Figure 2 This is a schematic diagram of one embodiment of the standing action sequence provided in this application. The standing action sequence includes an initial support phase 201 and a standing phase 202, which will be described below.

[0017] The initial support phase 201 includes: controlling the legged robot to enter the initial support state. In the initial support state, the minimum distance between the head and the contact surface is the first distance, the minimum distance between the hip and the contact surface is the second distance, the sum of the length of the torso and the second distance is the third distance, the ratio of the first distance to the third distance is greater than or equal to 0.65, there are at least two support points between the first lower limb and the contact surface, there is at least one support point between the second lower limb and the contact surface, the second lower limb establishes support contact with the contact surface at least through the first support part, the first surface distance between the first support part and the hip is less than the second surface distance between the lower limb end of the second lower limb and the hip, the knee joint angle of the first lower limb is 30° to 120°, the knee joint angle of the second lower limb is 45° to 150°, and the ratio of the minimum distance between the knee joints of the two lower limbs to the thigh length of the first lower limb is greater than or equal to 1.

[0018] In this embodiment, when executing the standing-up sequence, the legged robot is first controlled to enter an initial support state. In the initial support state, the first distance is the minimum distance between the head and the contact surface, and the second distance is the minimum distance between the hips and the contact surface. The length of the torso is the length of the torso measured along the vertical axis when the legged robot is in an upright position. The third distance is obtained by adding the length of the torso to the second distance, and is used to represent the reference height that the head can reach relative to the contact surface based on the current hip height. By setting the ratio of the first distance to the third distance, the position in which the head is relatively raised relative to the hips and the contact surface can be defined. Since the third distance includes the torso length and the height from the hips to the contact surface, when the proportion of the first distance to the third distance is greater than or equal to 0.65, it indicates that the head and upper torso have been lifted from near the contact surface to a certain height. This allows the legged robot to enter the standing-up phase 202 without starting from a posture where the head or upper torso is close to the contact surface, reducing the initial lifting stroke required for the upper torso to stand up and lowering the possibility of interference between the head, upper torso, and the contact surface. It also reserves space for subsequent rotation of the upper torso relative to the hips. It should be noted that in some embodiments, the head of the legged robot can be connected to the upper torso via the neck, with the neck serving as an intermediate connecting structure between the head and the upper torso. In other words, the head specifically refers to the head structure on the side of the neck away from the upper torso; that is, the head itself does not include the neck.

[0019] In the initial support state, there are at least two support points between the first lower limb and the contact surface, and at least one support point between the second lower limb and the contact surface. Thus, the two lower limbs can collectively form at least three support points, enabling the legged robot to obtain stable support through its two lower limbs before the standing-up phase. In some embodiments, when the contact surface is a flat surface, the first lower limb can support itself against the contact surface through its knee joint and lower limb tip, and the second lower limb can support itself against the contact surface through its knee joint. In practical applications, the contact surface may be uneven, have varying slopes, or be subject to flexible deformation. When the legged robot enters the initial support state from a falling posture, the order and area of ​​contact between different lower limb parts and the contact surface may change depending on the shape of the contact surface. For example, the support point between the first lower limb and the contact surface may be located at the lower limb tip (e.g., the side of the foot), knee joint, thigh, or calf, while the support point between the second lower limb and the contact surface may be located at the knee joint or thigh.

[0020] It should be noted that the first and second lower limbs are used to distinguish the two lower limbs of the legged robot and are not limited to the fixed lower limb. In some embodiments, when the first lower limb is the left leg, the second lower limb is the right leg; when the first lower limb is the right leg, the second lower limb is the left leg. Accordingly, the number of support points formed by the first and second lower limbs in the initial support state, the support location, and the support contact switching process during the standing up phase can be interchanged between the left and right sides according to the current falling posture and standing direction of the legged robot.

[0021] The second lower limb establishes supporting contact with the contact surface at least through a first supporting portion. The first surface distance between the first supporting portion and the hip is less than the second surface distance between the lower limb tip and the hip, indicating that the first supporting portion is closer to the hip relative to the lower limb tip in the limb structure of the second lower limb. The surface distance can be understood as the minimum distance between one part and another along the outer surface of the legged robot. In some embodiments, the first supporting portion can be the knee joint, thigh, or other lower limb part located between the knee joint and the hip of the second lower limb. Through the above surface distance relationship, the second lower limb can participate in support using the first supporting portion, which is closer to the hip, in the initial supported state. Because the first supporting portion is closer to the hip, it is easier for the first supporting portion to establish supporting contact with the contact surface when the legged robot is at a lower height, thus making it suitable for undertaking a supporting role before the standing-up phase.

[0022] In some embodiments, the first lower limb establishes supporting contact with the contact surface through at least a second support portion and a third support portion, wherein the surface distance between the second support portion and the hip is smaller than the surface distance between the third support portion and the hip. Thus, the second support portion is closer to the hip than the third support portion in the limb structure of the first lower limb, and the third support portion is closer to the lower limb tip than the second support portion. By making the second support portion closer to the hip than the third support portion, the first lower limb can simultaneously form at least two support points in the initial supporting state using both the support portion near the hip and the support portion near the lower limb tip, thereby improving the first lower limb's support capacity and posture constraint capacity for the legged robot before the standing-up phase.

[0023] The knee angle of the first lower limb is between 30° and 120°. For example, the knee angle of the first lower limb can be 30°, 45°, 60°, 75°, 90°, 105°, or 120°. When the knee angle of the first lower limb is less than 30°, the degree of folding between the thigh and lower leg is relatively high, which easily compresses the movement space for the lower limb end to establish support contact with the contact surface. When the knee angle of the first lower limb is greater than 120°, the degree of extension of the first lower limb is relatively high, which is not conducive to the first lower limb raising the center of gravity through knee joint lifting and lower limb end support coordination during the standing up phase. Therefore, controlling the knee angle of the first lower limb between 30° and 120° can ensure that the first lower limb has sufficient flexion while reserving the necessary movement space for the lower limb end to take over support and knee joint lifting, thereby improving the continuity of the transition from the initial support state to the standing up phase.

[0024] The knee angle of the second lower limb can range from 45° to 150°. For example, the knee angle of the second lower limb can be 45°, 60°, 75°, 90°, 105°, 120°, 135°, or 150°. When the knee angle of the second lower limb is less than 45°, the degree of folding between the thigh and lower leg is relatively high, and the lower limb tip may be too close to the hip, requiring a large joint extension movement when switching from the first support point to the lower limb tip support. When the knee angle of the second lower limb is greater than 150°, the second lower limb is close to a straight position, making it difficult for the first support point to establish stable support contact with the contact surface in the initial support state. This also results in insufficient adjustment margin for the second lower limb during the rising phase, affecting the lower limb tip's approach to the contact surface and establishment of support contact. Therefore, by controlling the knee joint angle of the second lower limb between 45° and 150°, the second lower limb can participate in low-position support through the first support part in the initial support state, and has appropriate adjustment space in the standing up stage, so that the support area of ​​the second lower limb can be smoothly transferred from the first support part to the lower limb end of the second lower limb.

[0025] A ratio of the minimum distance between the knees of the two lower limbs to the thigh length of the first lower limb is greater than or equal to 1, ensuring sufficient lateral separation between the two lower limbs in the initial support state. The thigh length of the first lower limb can be defined as the length of the link between the first lower limb and the hip joint and the knee joint of the first lower limb. Since both the first and second lower limbs participate in the initial support state, a small distance between the knees results in a small support span, making lateral tilting more likely during the standing process. When the minimum distance between the knees reaches or exceeds the thigh length of the first lower limb, the two lower limbs can form a wider support span on the contact surface, reducing the risk of lateral tipping during the initial standing phase of the legged robot and providing lateral movement space for the knee joint lifting of the first lower limb and the switching of support contact between the second lower limb and the second lower limb.

[0026] By considering the ratio between the first and third distances, the arrangement of support points between the two lower limbs and the contact surface, the distance between the first support part and the first surface of the hip, the range of the knee joint angle between the two lower limbs, and the minimum distance between the knee joints of the two lower limbs, the legged robot can form an initial support state with the joint participation of the two lower limbs before the standing-up phase, and then perform the subsequent standing-up action.

[0027] The standing phase 202 includes: controlling the center of mass of the legged robot to rise; during the rising of the center of mass: controlling the upper torso to rotate relative to the hip, wherein the rotation angle of the upper torso relative to the hip is greater than or equal to 20°; controlling the knee joint of the first lower limb to rise away from the contact surface, and during the rising of the knee joint of the first lower limb away from the contact surface, the lower limb end of the first lower limb makes support contact with the contact surface; controlling the first support part of the second lower limb to disengage from the contact surface, and controlling the lower limb end of the second lower limb to make support contact with the contact surface.

[0028] In this embodiment, after the legged robot enters the standing stage 202 from the initial support state, the processor controls the legged robot's center of mass to gradually rise away from the contact surface. This rise in the center of mass can be achieved through at least some of the movements in the rotation of the upper torso relative to the hip, the raising of the knee joint of the first lower limb, and the switching of the support position of the second lower limb. Thus, the legged robot can gradually transition from the initial support state to a standing process in which the lower limbs participate in support.

[0029] During the ascent of the center of gravity, the processor controls the upper torso to rotate relative to the hips, with the rotation angle being greater than or equal to 20°. This rotation of the upper torso relative to the hips can involve acceleration; during this acceleration, the change in rotational angular velocity creates an upward impulse, assisting the legged robot's center of gravity in moving upwards. For example, the rotation angle of the upper torso relative to the hips can be 20°, 30°, 45°, 60°, 75°, 90°, 180°, 270°, or 360°. By ensuring that the upper torso rotates at least 20° relative to the hips, sufficient rotational amplitude is guaranteed during the ascent phase, assisting the legged robot's center of gravity in rising.

[0030] In some embodiments, in the initial support state, the upper torso faces the first lower limb, so that the upper torso is in a deflected posture relative to the hip. The standing-up phase 202 further includes controlling the upper torso to rotate from the deflected posture to a forward posture relative to the hip; wherein, in the standing-up phase, the angle of rotation of the upper torso relative to the hip from the deflected posture to the forward posture is less than or equal to 100°. That is, when the legged robot enters the initial support state, the upper torso can pre-form a deflected posture relative to the hip, so that a posture space for subsequent rotation and standing up is formed between the upper torso, hip, and two lower limbs. By making the upper torso face the first lower limb, the upper torso can have a larger rotational margin in the low support state, thereby facilitating the use of the rotation of the upper torso relative to the hip to assist in body posture adjustment and center of gravity rise in the standing-up phase 202. In the standing-up phase 202, the processor can control the upper torso to rotate from the deflected posture to the forward posture relative to the hip. In this context, a positive posture can be understood as the posture in which the head, upper torso, hips, knees, and distal ends of the leg muscles are aligned when the leg robot is approaching or in a standing position. The angle of rotation of the upper torso relative to the hips from a deflected posture to a positive posture is less than or equal to 100°. For example, the angle of rotation of the upper torso relative to the hips from a deflected posture to a positive posture can be 20°, 30°, 45°, 60°, 75°, 90°, or 100°. When the upper torso rotates from a deflected posture to a positive posture relative to the hips, the upper torso can gradually return from a deflected state facing the first lower limb to a state adapted to the hip orientation, allowing the leg robot to simultaneously adjust its torso orientation during the ascent of its center of gravity. This reduces the need for additional torso orientation adjustments after the leg robot enters a bipedal support position, improving the continuity of the standing motion.

[0031] During the ascent of the center of gravity, the processor also controls the knee joint of the first lower limb to rise away from the contact surface. As the knee joint of the first lower limb rises away from the contact surface, the distal end of the first lower limb makes supporting contact with the contact surface. Therefore, when the first lower limb switches from low-position support to distal-position support, it can still output supporting force to the contact surface through the distal end of the first lower limb, allowing the first lower limb to gradually transition from low-position multi-point support to distal-position support. Because the distal end of the first lower limb maintains supporting contact with the contact surface during the knee joint's ascent, the first lower limb can continuously provide support to the body during the support contact switching process, reducing posture fluctuations caused by sudden changes in support contact.

[0032] During the ascent of the center of gravity, the processor also controls the first support portion of the second lower limb to detach from the contact surface and controls the distal end of the second lower limb to make supporting contact with the contact surface. The first support portion can be a part of the second lower limb that is closer to the hip than the distal end, such as the knee joint, thigh, or other lower limb parts located between the knee joint and hip. The detachment of the first support portion of the second lower limb from the contact surface allows the second lower limb to release low-level support near the hip; the establishment of supporting contact between the distal end of the second lower limb and the contact surface allows the second lower limb to transition to a foot-supported state. Thus, the second lower limb can gradually transition from low-level support by the first support portion to support by the distal end, enabling the legged robot to switch from low-level support to bipedal support during the ascent of the center of gravity.

[0033] It should be noted that during the ascent of the center of mass, the aforementioned actions of controlling the rotation of the upper torso relative to the hip, controlling the lifting of the knee joint of the first lower limb, and controlling the first support part of the second lower limb to disengage from the contact surface and establishing support contact at the lower limb end can be executed sequentially, partially overlapped, or simultaneously. In one possible implementation, the processor can first control the rotation of the upper torso relative to the hip, causing the upper torso to adjust its posture, then control the lifting of the knee joint of the first lower limb, and control the second lower limb to switch from support at the first support part to support at the lower limb end. In another possible implementation, the processor can first control the stable support of the lower limb end, and control the knee joint of the first lower limb to lift away from the contact surface, then control the rotation of the upper torso relative to the hip, while simultaneously controlling the first support part of the second lower limb to disengage from the contact surface and establishing support contact at the lower limb end. In another possible implementation, the processor can first control the distal end of the second lower limb to approach and establish supporting contact with the contact surface, then control the first supporting part of the second lower limb to disengage from the contact surface, and simultaneously control the rotation of the upper torso relative to the hip and the raising of the knee joint of the first lower limb. In yet another possible implementation, the processor can simultaneously control the rotation of the upper torso relative to the hip, the raising of the knee joint of the first lower limb, and the switching of the supporting part of the second lower limb, so that the upper torso posture adjustment, the switching of the first lower limb support, and the switching of the second lower limb support are completed collaboratively within the same center of mass ascent phase.

[0034] In some embodiments, the standing phase 202 may further include: during the rotation of the upper torso relative to the hips, the distance between the distal end of at least one upper limb and the contact surface is greater than the distance between the corresponding elbow joint and the contact surface; or, during the rotation of the upper torso relative to the hips, controlling the distal end of at least one upper limb to move away from the contact surface. During the rotation of the upper torso relative to the hips, maintaining the upper limb in a high position or swinging upwards can create a larger radius of rotation for the upper limb's mass distribution relative to the upper torso, and coordinate the upper limb movement with the accelerated rotation of the upper torso to generate an upward impulse, assisting the legged robot's center of mass in rising. When the processor controls the accelerated rotation of the upper torso relative to the hips, the high posture or upward swinging motion of the upper limbs can increase the attitude adjustment and angular momentum change of the upper body structure, causing the upper torso rotation to generate an upward impulse. Therefore, based on the support constraint formed by the lower limb end of the first lower limb and the support part of the second lower limb with the contact surface, the rotation of the upper limb and the upper torso can cooperate with the support reaction force of the contact surface to form an effect that is conducive to the movement of the center of mass away from the contact surface, so that the body can obtain an impulse in the direction away from the contact surface, thereby assisting the center of mass of the legged robot to rise.

[0035] Please see Figure 3 , Figure 3This is a schematic diagram of a legged robot in its initial support state. In the corresponding embodiment, the head and upper torso of the legged robot are raised relative to the contact surface. The first distance d1 between the head and the contact surface, and the second distance d2 between the hip and the contact surface, are such that d1 satisfies the ratio requirement to a third distance. The two lower limbs are spread out on the contact surface. The first lower limb forms at least two support points with the contact surface, and the second lower limb forms at least one support point with the contact surface, thereby enabling the two lower limbs to jointly provide a low-level support base. The second lower limb can establish support contact with the contact surface by using the knee joint, thigh, or other parts near the hip as the first support point, and this first support point is closer to the hip than the lower limb tip of the second lower limb, so that the support area of ​​the second lower limb can be transferred from the first support point to the lower limb tip during the subsequent standing-up phase. Figure 3 The support state shown is only an example of the initial support state. The specific support points of the first and second lower limbs can be adjusted according to the fall posture, joint range of motion, and contact surface state of the legged robot, as long as the number of lower limb support points, knee joint angle, and distance between the two knees are satisfied in the initial support state.

[0036] Please see Figure 4 , Figure 4 This is a schematic diagram of a legged robot's support state at a certain moment during the standing-up phase 202. In the corresponding embodiment, the legged robot is composed of... Figure 3 After entering the standing-up phase 202 from the initial support state, the legged robot's upper body rotates relative to its hips. Both upper limbs rise away from the contact surface as the upper body rotates, and the knee joint of the first lower limb rises away from the contact surface. The distal end of the first lower limb maintains supporting contact with the contact surface, gradually transitioning the first lower limb from low-position multi-point support in the initial support state to distal end support. The first support part of the second lower limb gradually detaches from the contact surface, and the distal end of the second lower limb approaches the contact surface and prepares to establish supporting contact, thus transitioning the second lower limb from low-position support near the hips to distal end support.

[0037] When executing a standing-up sequence, the legged robot first enters an initial support state. In this state, by ensuring the ratio of the first to the third distance between the head and the contact surface is greater than or equal to 0.65, the robot already has a certain degree of upper body elevation before standing up, reducing the required upper torso movement during subsequent standing. Simultaneously, there are at least two support points between the first lower limb and the contact surface, and at least one support point between the second lower limb and the contact surface. This allows the robot to form a multi-point support base with its two lower limbs in a low-position posture, thus achieving a relatively stable support state in the initial stage of standing up. The second lower limb establishes support contact with the contact surface through the first support part, and the distance between the first support part and the hip on the first surface is less than the distance between the lower limb tip and the hip on the second surface. This allows the second lower limb to initially participate in low-position support through a part relatively close to the hip, and then transition to support at the lower limb tip during standing up, facilitating force generation and controlling the overall center of gravity rise during subsequent standing. The knee joint angles of the first and second lower limbs are within their respective ranges, and the distance between the knee joints of the two lower limbs matches the thigh length of the first lower limb, allowing the two lower limbs to form a laterally spread supporting posture on the contact surface. This posture helps to expand the low-level support range of the robot, giving it a more stable posture base, and facilitating the control of the lower limb joint force exertion during subsequent standing up, thus controlling the overall center of gravity rise.

[0038] During the standing-up phase, the center of gravity of the legged robot is controlled to rise. During this rise, the upper torso rotates relative to the hips at an angle greater than or equal to 20°, generating an upward impulse that assists in the upward movement of the robot's center of gravity. Further, the knee joint of the first lower limb is raised away from the contact surface, maintaining contact between the lower limb's distal end and the contact surface during this raising process. This allows the first lower limb to gradually transition from low-level multi-point support to distal end support. Simultaneously, the support area of ​​the second lower limb shifts from the first support area to the distal end, completing the transition from near-hip support to distal end support. This continuous switching of support states reduces reliance on distal end support during standing, lowering the risk of pressure injury to the distal end and shortening the time required to recover from a fallen posture to a bipedal support state, thus increasing the speed of standing up.

[0039] In some embodiments, in the initial supported state, there is at least one support point located at the knee joint or thigh between the first lower limb and the contact surface; the first support portion of the second lower limb is located at the knee joint or thigh of the second lower limb.

[0040] In this embodiment, both the first and second lower limbs can participate in low-position support through limb parts closer to the hip relative to the lower limb's end, making it easier for the legged robot to establish a stable initial support state in a low-position posture after falling. Specifically, at least one support point between the first lower limb and the contact surface can be located at the knee joint or the thigh of the first lower limb. When the first lower limb is in a flexed and abducted posture, the knee joint of the first lower limb can establish support contact with the contact surface as a support point between the first lower limb and the contact surface. When the contact surface has local protrusions, slope changes, or the thigh of the first lower limb has a small angle relative to the contact surface, the thigh of the first lower limb can also establish support contact with the contact surface as a support point between the first lower limb and the contact surface. By ensuring that there is at least one support point located at the knee joint or thigh between the first lower limb and the contact surface, the first lower limb can participate in support in the initial support state using a part closer to the hip relative to the lower limb's end. This support point can work together with other support points of the first lower limb to form at least two support points between the first lower limb and the contact surface. Thus, before the knee joint of the first lower limb is raised away from the contact surface, the first lower limb can provide support for the legged robot and reduce the risk of lateral tipping or posture slippage of the legged robot during the switching between upper body rotation and lower limb support contact.

[0041] The first support point of the second lower limb is located at the knee joint or thigh. Since the knee joint and thigh of the second lower limb are closer to the hip than the lower limb's distal end, the second lower limb can establish supporting contact with the contact surface through the knee joint or thigh when the legged robot is in its initial supported state. Therefore, the second lower limb can participate in support through the first support point before the lower limb's distal end establishes supporting contact with the contact surface, thus forming at least three support points in conjunction with the first lower limb.

[0042] With the above settings, the legged robot can use different parts of the hip, such as the knee joint and thigh, to participate in the support in the initial support state. This improves the adaptability of the initial support state to different falling postures and different contact surface conditions, and provides a support basis for subsequent control of the knee joint of the first lower limb to lift away from the contact surface, control of the first support part of the second lower limb to detach from the contact surface, and control of the lower limb end of the second lower limb to make support contact with the contact surface.

[0043] In some embodiments, in the initial supported state, one support point between the first lower limb and the contact surface is located at the knee joint of the first lower limb, and the other support point between the first lower limb and the contact surface is located at the lower limb end of the first lower limb; the first support part of the second lower limb is the knee joint of the second lower limb.

[0044] In this embodiment, the two lower limbs form a support state in the initial support state, which is jointly participated in by the knee joint of the first lower limb, the distal end of the first lower limb, and the knee joint of the second lower limb. The knee joint of the first lower limb is located between the connection end of the first lower limb to the hip and the distal end of the first lower limb, and the knee joint of the second lower limb is located between the connection end of the second lower limb to the hip and the distal end of the second lower limb. Therefore, compared with the corresponding distal ends of the lower limbs, the knee joints of the first and second lower limbs are located closer to the hip. When the legged robot is in a low posture after falling, the distal ends of the lower limbs may be located far from the contact surface, or the orientation of the distal ends of the lower limbs may make it difficult to directly establish stable support contact with the contact surface. At this time, if both lower limbs are directly controlled to establish support contact through the distal ends of the lower limbs, a large posture adjustment range is required, which can easily increase the difficulty of the posture adjustment process before getting up. By having the knee joints of the first and second lower limbs participate in the support, the two lower limbs can establish support contact with the contact surface while maintaining a bent state, thereby reducing the lower limb extension range required to enter the initial support state.

[0045] Specifically, the knee joint of the first lower limb can serve as a support point on the side closer to the hip, while the distal end of the first lower limb can serve as a support point on the side farther from the hip. Thus, the first lower limb can form two support points on the contact surface through the knee joint and the distal end, providing both support and postural constraint in the initial supported state. Since the distal end of the first lower limb has already established supporting contact with the contact surface, when the knee joint of the first lower limb subsequently rises away from the contact surface, the first lower limb can still output supporting force to the contact surface through the distal end, thereby reducing postural fluctuations when the first lower limb switches from knee joint support to distal end support.

[0046] The knee joint of the second lower limb serves as the primary support point, allowing it to establish support contact with the contact surface before the distal end of the second lower limb does. Since the knee joint of the second lower limb is closer to the hip than the distal end, it is easier for the knee joint to approach the contact surface when the legged robot is in a low-lying posture and the second lower limb is bent. Therefore, the second lower limb can initially participate in support through the knee joint, and then, during the rise of the center of gravity, control the distal end of the second lower limb to establish support contact with the contact surface, gradually switching the support from the knee joint to the distal end.

[0047] With the aforementioned support point configuration, the legged robot can form at least three support points in its initial supported state, utilizing the knee joint of the first lower limb, the distal end of the first lower limb, and the knee joint of the second lower limb. This supported state allows the legged robot to obtain a support base jointly provided by both lower limbs before the standing-up phase, and provides a continuous transition condition for subsequently controlling the knee joint of the first lower limb to rise away from the contact surface, controlling the knee joint of the second lower limb to disengage from the contact surface, and controlling the distal end of the second lower limb to establish support contact with the contact surface.

[0048] In some embodiments, in the initial supported state, a plane that intersects the geometrically enclosed area of ​​the thigh, knee joint and calf of the first lower limb is used as the first reference plane, and the angle between the first reference plane and the contact surface is less than or equal to 45°; a plane that intersects the geometrically enclosed area of ​​the thigh, knee joint and calf of the second lower limb is used as the second reference plane, and the angle between the second reference plane and the contact surface is greater than or equal to 45°.

[0049] In this embodiment, please refer to Figure 3 The first reference plane A is a plane that intersects the geometrically enclosed regions of the thigh, knee, and lower leg of the first lower limb simultaneously. That is, the first reference plane A can pass through the geometrically enclosed regions of the thigh, knee, and lower leg of the first lower limb, thus representing the overall posture formed by the thigh, knee, and lower leg of the first lower limb. A first angle α is formed between the first reference plane A and the contact surface C, which can be the angle between the first reference plane A and the contact surface C located on the outer side of the thigh of the first lower limb. In the initial supported state, the angle between the first reference plane A and the contact surface C is less than or equal to 45°, indicating that the thigh, knee, and lower leg of the first lower limb are tilted towards the contact surface C, and the first lower limb as a whole is closer to the contact surface C. Therefore, the knee or thigh of the first lower limb can more easily establish supporting contact with the contact surface C, and the lower limb tip of the first lower limb can also establish supporting contact with the contact surface C, so that the first lower limb forms at least two support points in the initial supported state. For example, the first included angle α between the first reference plane A and the contact surface C can be 45°, 40°, 30°, 20°, 10°, or 0°. As the included angle between the first reference plane A and the contact surface C decreases, the thigh, knee joint, and lower leg of the first lower limb are closer to the contact surface C, reducing the difficulty for the knee joint or thigh of the first lower limb to establish supporting contact with the contact surface C. With the above configuration, the first lower limb can participate in support through the knee joint or thigh in the initial support state, and form a supporting base with the lower limb end of the first lower limb.

[0050] The second reference plane B is a plane that intersects simultaneously with the geometrically enclosed areas of the thigh, knee joint, and lower leg of the second lower limb. In other words, the second reference plane B can pass through the geometrically enclosed areas of the thigh, knee joint, and lower leg of the second lower limb, thus representing the overall posture formed by the thigh, knee joint, and lower leg of the second lower limb. A second angle β is formed between the second reference plane B and the contact surface C, which can be the angle between the second reference plane B and the contact surface C located on the outer side of the thigh of the second lower limb. In the initial supported state, the angle between the second reference plane B and the contact surface C is greater than or equal to 45°, indicating that the thigh, knee joint, and lower leg of the second lower limb have a greater degree of elevation relative to the contact surface C. Therefore, the second lower limb can establish supporting contact with the contact surface C through the first supporting part, while simultaneously allowing the lower limb tip of the second lower limb to have swing space relative to the contact surface C, facilitating the movement of the lower limb tip towards the contact surface C and the establishment of supporting contact during the rising phase 202. For example, the second included angle β between the second reference plane B and the contact surface C can be 45°, 50°, 60°, 70°, 80°, or 90°. As the included angle between the second reference plane B and the contact surface C increases, the degree of elevation of the thigh, knee joint, and lower leg of the second lower limb relative to the contact surface C increases, and the swing space of the lower limb tip relative to the contact surface C increases. Therefore, the second lower limb can participate in support through the knee joint or thigh in the initial support state, and control the movement of the lower limb tip towards the contact surface C during the rising phase 202.

[0051] By making the angle between the first reference plane A and the contact surface C less than or equal to 45°, and the angle between the second reference plane B and the contact surface C greater than or equal to 45°, the first and second lower limbs can form different posture relationships in the initial support state. The first lower limb is closer to the contact surface C, which is beneficial for the first lower limb to form at least two support points involving the knee joint or thigh and the lower limb end. The second lower limb has a greater degree of elevation relative to the contact surface C, which is beneficial for the second lower limb to provide space for the lower limb end to move towards the contact surface C and establish support contact while supporting itself through the first support point. Thus, the legged robot can form at least three support points through its two lower limbs in the initial support state, and in the standing-up phase 202, the first and second lower limbs can gradually transition to the corresponding lower limb end support according to different support contact switching methods. This setting can reduce posture fluctuations caused by the simultaneous release of the original support contact by the first and second lower limbs, and improve the continuity of the legged robot from the initial support state to the bipedal support state.

[0052] In some embodiments, in the initial supported state, the angle between the thigh of the first lower limb and the contact surface is 0° to 30°, the angle between the thigh of the second lower limb and the contact surface is 0° to 45°, and the hip is in contact with or separate from the contact surface.

[0053] In this embodiment, the angle between the thigh of the first lower limb, the thigh of the second lower limb, and the contact surface can be an acute angle formed between the thigh length direction of the corresponding lower limb and the contact surface. For example, the angle between the thigh of the first lower limb and the contact surface can be 0°, 5°, 10°, 15°, 20°, 25°, or 30°. By making the angle between the thigh of the first lower limb and the contact surface 0° to 30°, the thigh of the first lower limb can maintain a small degree of inclination relative to the contact surface in the initial supported state, making the first lower limb closer to the contact surface and extending laterally towards the body. As a result, the knee joint, thigh area, or lower limb end of the first lower limb can more easily form multi-point support with the contact surface, which can improve the support stability of the first lower limb in a low posture. The angle between the thigh of the second lower limb and the contact surface can be 0°, 10°, 20°, 30°, 40°, or 45°. By setting the angle between the thigh of the second lower limb and the contact surface to 0° to 45°, the thigh of the second lower limb can be positioned in a low posture close to the contact surface during the initial support state. This allows the knee joint or a local area of ​​the thigh of the second lower limb to establish support contact with the contact surface as the first support point. When both the thighs of the first and second lower limbs approach the contact surface at a small angle, the two lower limbs can form a laterally extended support posture on the contact surface. This laterally extended support posture increases the support span of the two lower limbs in the low position, giving the robot a more stable posture base. This facilitates control of the lower limb joint force during subsequent standing up, controlling the overall center of gravity rise.

[0054] In the initial support state, the hips can be in contact with or separated from the contact surface. When the hips are separated from the contact surface, the legged robot mainly maintains the initial support state through the support contact between the two lower limbs and the contact surface. This helps to reduce the movement required for the hips to lift off the contact surface during the standing up phase, and reduces the joint output required for subsequent standing up. As a result, the standing up speed of the legged robot from the initial support state to the bipedal support state can be improved.

[0055] By controlling the angle between the thigh of the first lower limb and the contact surface, and the angle between the thigh of the second lower limb and the contact surface, and allowing the hip to contact or separate from the contact surface, the two lower limbs can form a low-lying, laterally extended support posture on the contact surface. This posture helps to expand the low-lying support range of the robot, giving the legged robot a more stable posture base before standing up, and facilitating subsequent upward movement by driving the center of mass. When the hip separates from the contact surface, it can also reduce the joint output required for the subsequent standing up phase, improving the execution efficiency of the standing up action.

[0056] In some embodiments, in the initial supported state, the distal end of the first lower limb establishes supporting contact with the contact surface through the side area of ​​the foot. The standing-up phase includes: during the upward movement of the center of mass: controlling the upper torso to rotate relative to the hips; controlling the knee joint of the first lower limb to lift away from the contact surface, so that the knee joint of the first lower limb releases supporting contact with the contact surface, and controlling the contact area between the distal end of the first lower limb and the contact surface to transfer from the side area of ​​the foot to the foot area; after the knee joint of the first lower limb releases supporting contact with the contact surface, controlling the knee joint of the second lower limb to release supporting contact with the contact surface, and controlling the distal end of the second lower limb to make supporting contact with the contact surface, so that the legged robot enters a bipedal supported state.

[0057] In this embodiment, the foot region is the bottom surface of the distal end of the first lower limb facing the contact surface in a normal standing state; the foot side region is the edge region located on one side of the foot region. In the initial support state, the distal end of the first lower limb establishes support contact with the contact surface through the foot side region. Since the first lower limb can be in a bent, abducted, and close-to-the-contact posture in the initial support state, and one support point between the first lower limb and the contact surface can be located at the knee joint of the first lower limb, the distal end of the first lower limb is usually in a lateral tilted posture relative to the contact surface. By having the distal end of the first lower limb establish support contact with the contact surface through the foot side region, the first lower limb can still participate in support through the distal end while keeping the knee joint in contact with the ground or close to the contact surface, thereby adapting to the abducted and low-bent posture of the first lower limb.

[0058] During the rising phase 202, as the center of mass rises, the processor controls the rotation of the upper torso relative to the hips and controls the knee joint of the first lower limb to rise away from the contact surface, thus releasing the knee joint from support contact with the contact surface. As the knee joint of the first lower limb rises away from the contact surface, the distal end of the first lower limb continues to maintain support contact with the contact surface, and the contact area between the distal end of the first lower limb and the contact surface shifts from the side of the foot to the sole of the foot. Specifically, as the knee joint of the first lower limb rises, the posture of the thigh and lower leg relative to the contact surface changes, and the distal end of the first lower limb can gradually adjust around its contact area with the contact surface, gradually transitioning the support from the side of the foot to the sole of the foot. Thus, the first lower limb can complete the contact area transfer while the distal end continues to provide support, transitioning from a state where the knee joint and the side of the foot jointly provide support to a state where the sole of the foot provides support. By controlling the shift of the contact area between the distal end of the first lower limb and the contact surface from the side of the foot to the ball of the foot, the first lower limb can gradually approach the foot-supported posture of a normal standing state during the standing process. Because the distal end of the first lower limb continues to maintain contact with the contact surface during the contact area shift, the first lower limb can continue to output supporting force to the contact surface when the knee joint releases the supporting contact, thereby reducing the postural fluctuation of the first lower limb when switching from knee joint support to ball of the foot support.

[0059] After the knee joint of the first lower limb releases its support contact with the contact surface, the processor controls the knee joint of the second lower limb to release its support contact with the contact surface, and then controls the distal end of the second lower limb to maintain support contact with the contact surface. Since the distal end of the first lower limb has already established support contact with the contact surface through the foot area, the knee joint of the second lower limb can release its support contact with the contact surface based on the support provided by the first lower limb. This reduces the posture fluctuations caused by the simultaneous release of support contact by the knee joints of the first and second lower limbs. After the distal end of the second lower limb establishes support contact with the contact surface, the support base of the legged robot is supported by the distal end of the first lower limb and the knee joint of the second lower limb, further switching to the joint support of the distal ends of the first and second lower limbs. At this time, the first lower limb can maintain support contact with the contact surface through the foot area, and the second lower limb can maintain support contact with the contact surface through its corresponding distal end, enabling the legged robot to enter a bipedal support state.

[0060] Through the above process, during the ascent of the legged robot's center of gravity, the first lower limb first completes the transfer of support from the side of the foot to the center of the foot, and the knee joint of the first lower limb releases its support contact; subsequently, the knee joint of the second lower limb releases its support contact, and the distal end of the second lower limb takes over the support. This support contact switching sequence allows the distal end of at least one lower limb to continuously provide support during the ascent process, reducing the posture changes caused by the simultaneous release of knee joint support from both lower limbs, and improving the continuity of the legged robot's transition from the initial support state to the bipedal support state.

[0061] In practice, the posture of a legged robot after falling can be either supine or prone. Because the relative positions of the torso, two lower limbs, and the contact surface differ in different falling postures, the posture adjustment methods required for the legged robot to enter the initial support state also differ. These will be explained separately below.

[0062] In some embodiments, during the initial support phase, the instructions, when executed by at least one processor, also cause the legged robot to: control the torso to rise based on a supine posture and control the first lower limb to detach from the contact surface; after the first lower limb separates from the contact surface, control the first lower limb to cross over the second lower limb and re-establish contact with the contact surface; control the formation of at least two support points between the first lower limb and the contact surface, and at least one support point between the second lower limb and the contact surface, to enter the initial support state.

[0063] In this embodiment, the legged robot can enter an initial support state based on a supine posture. The supine posture can be a posture where the legged robot's back faces or is close to the contact surface. In the supine posture, the knee joints of the two lower limbs typically face away from the contact surface, and the original contact area between the two lower limbs and the contact surface may be concentrated on the back of the calf, the back of the thigh, or a localized area of ​​the foot. At this time, the knee joints of the first and second lower limbs lack the posture conditions to directly face the contact surface, and it is difficult for the two lower limbs to directly form an initial support state with at least two support points for the first lower limb and at least one support point for the second lower limb. Based on this, in the initial support stage, the processor can first control the torso to rise relative to the contact surface, causing the head and upper torso to move away from the contact surface. By controlling the torso to rise, the distance between the torso and the contact surface can be increased, reserving space for the first lower limb to disengage from the contact surface and cross over the second lower limb, and reducing the possibility of interference between the first lower limb and the torso or contact surface during adjustment.

[0064] During or after controlling the torso elevation, the processor can control the first lower limb to detach from the contact surface. Detachment releases the original contact constraint between the first lower limb and the contact surface in a supine position, allowing the first lower limb to flex, abduct, or cross over relative to the hip. Because the first lower limb has greater postural adjustment space after being lifted from the contact surface, the processor can further control the first lower limb to cross over the second lower limb. After the first lower limb separates from the contact surface, the processor controls the first lower limb to cross over the second lower limb and re-establish contact with the contact surface. Crossing over the second lower limb changes the relative position between the first and second lower limbs, adjusting the first lower limb to a position where it can provide lateral support with the second lower limb. Simultaneously, the process of the first lower limb crossing over the second lower limb changes the orientation of the first lower limb's knee joint, gradually adjusting it from facing away from the contact surface to facing or approaching it. Thus, the knee joint of the first lower limb possesses the postural conditions for establishing supporting contact with the contact surface. After the first lower limb re-establishes contact with the contact surface, the processor controls the formation of at least two support points between the first lower limb and the contact surface, and controls the formation of at least one support point between the second lower limb and the contact surface. For example, the first lower limb can form two support points with the contact surface through the knee joint and the lower limb tip, while the second lower limb can form one support point with the contact surface through the knee joint, thigh, or other parts closer to the hip relative to the lower limb tip. Through the above control process, the legged robot can adjust from a supine posture to an initial support state in which both lower limbs participate in the support. By controlling the first lower limb to straddle the second lower limb, the lateral distance between the first and second lower limbs can be increased, allowing the first and second lower limbs to form a larger support span on the contact surface.

[0065] Please see Figure 5-A , Figure 5-B and Figure 5-C , Figure 5-A , Figure 5-B and Figure 5-C This is a schematic diagram illustrating the process by which a legged robot enters its initial support state from a supine posture. Figure 5-A As shown, the legged robot is in a supine position, with its back facing or close to the contact surface. In this position, the two lower limbs have not yet formed a suitable lateral support base for the standing-up phase. Based on this, the processor controls the torso to rise relative to the contact surface, causing the head and upper torso to move away from the contact surface, and reserving space for adjustment of the first lower limb. Simultaneously, the processor controls the first lower limb to bend and disengage from the contact surface, thus releasing the contact constraint between the first lower limb and the contact surface from the supine position. Figure 5-B As shown, after the torso is raised, the processor controls the first lower limb to cross over the second lower limb, adjusting the first lower limb from its original position adjacent to the second lower limb to a position where it can provide lateral support with the second lower limb. Figure 5-CAs shown, after the first lower limb crosses over the second lower limb, the processor controls the first lower limb to move towards the contact surface again and establish contact with the contact surface. At the same time, the processor adjusts the degree of flexion, abduction, and orientation of the lower limb ends of the first and second lower limbs, so that at least two support points are formed between the first lower limb and the contact surface, and at least one support point is formed between the second lower limb and the contact surface.

[0066] During the process of entering the initial support state from a supine position, actions such as trunk lifting, the first lower limb leaving the contact surface, the first lower limb crossing over the second lower limb, the first lower limb re-entering the contact surface, and the formation of the support point can be executed sequentially, partially overlapped, or simultaneously adjusted according to the current posture and contact state. For example, the processor can control the first lower limb to bend and leave the contact surface while the trunk is lifting, or it can simultaneously adjust the knee angle of the second lower limb as the first lower limb crosses over the second lower limb, so that both lower limbs can more quickly form the initial support state that meets the requirements for getting up.

[0067] Through the aforementioned process of entering the initial support state from a supine posture, the legged robot can adjust the state from a supine posture where the knee joint is facing away from the contact surface and the support span of the two lower limbs is insufficient, to a state where there are at least two support points between the first lower limb and the contact surface, and at least one support point between the second lower limb and the contact surface. This reduces the legged robot's reliance on upper limb end support when transitioning from a supine posture to the standing-up phase, and also reduces motion interference between the two lower limbs during the process of entering the initial support state.

[0068] In some embodiments, during the initial support phase, the instructions, when executed by at least one processor, also cause the legged robot to: establish temporary auxiliary support contact with the contact surface based on a prone posture; raise the torso based on the temporary auxiliary support contact; and control the first lower limb to form at least two support points with the contact surface, and the second lower limb to form at least one support point with the contact surface, in order to enter the initial support state.

[0069] In this embodiment, the legged robot can enter an initial support state based on a prone posture. The prone posture can be the legged robot facing forward or close to the contact surface. In the prone posture, the head, upper torso, or hips may be close to or against the contact surface, and the small gap between the torso and the contact surface restricts the movement space of the two lower limbs. If the two lower limbs are directly controlled to form the initial support state, the lower limbs may interfere with the contact surface, the torso, or another lower limb. Therefore, in the initial support stage, the processor can first control at least one of the two upper limbs to establish temporary auxiliary support contact with the contact surface, and raise the torso based on this temporary auxiliary support contact. Through this temporary auxiliary support contact, the head, upper torso, or hips move away from the contact surface. This increases the gap between the torso and the contact surface, reserving movement space for the first and second lower limbs, and reducing the possibility of movement interference between the lower limbs and the contact surface or torso during adjustment. It should be noted that the support contact between the upper limbs and the contact surface is only a temporary auxiliary support contact. During the process of entering the initial support state from a prone position, temporary auxiliary support contact can be provided by one upper limb or by both upper limbs together. The temporary auxiliary support contact can be released after at least two support points are formed between the first lower limb and the contact surface, and at least one support point is formed between the second lower limb and the contact surface.

[0070] After the torso is lifted based on temporary auxiliary support contact, the processor controls the first lower limb to form at least two support points with the contact surface, and controls the second lower limb to form at least one support point with the contact surface. For example, the first lower limb can form two support points with the contact surface through the knee joint and the lower limb tip, while the second lower limb can form one support point with the contact surface through the knee joint, thigh, or other parts closer to the hip relative to the lower limb tip. Through the above control process, the legged robot can adjust from a prone posture to an initial supported state, so that the two lower limbs form a support base provided by at least three support points before the start of the standing-up phase 202.

[0071] Please see Figure 6-A and Figure 6-B , Figure 6-A and Figure 6-B This is a schematic diagram illustrating the process by which a legged robot enters its initial support state from a prone posture. Figure 6-AAs shown, the legged robot is in a prone position, with its torso facing or close to the contact surface. In this position, the legged robot can first establish temporary auxiliary support contact between at least one upper limb and the contact surface, raising the upper torso and head relative to the contact surface, creating space around the hips for the lower limbs to swing and abduct. As the torso rises, the processor can control the first lower limb to bend relative to the hips and extend outwards, gradually bringing the knee joint, thigh area, or distal end of the first lower limb closer to the contact surface. Simultaneously, the processor can control the second lower limb to maintain a bent or abducted posture, ensuring that the knee joint, thigh area, or other first support parts near the hips of the second lower limb have the conditions to establish support contact with the contact surface. Figure 6-B As shown, after the torso is raised and the lower limbs are given room for adjustment, the processor further adjusts the posture of the first and second lower limbs so that at least two support points are formed between the first lower limb and the contact surface, at least one support point is formed between the second lower limb and the contact surface, and at least one temporary auxiliary support contact is made between the upper limb and the contact surface.

[0072] During the process of entering the initial support state from a prone position, actions such as temporary auxiliary support contact, trunk elevation, the formation of at least two support points by the first lower limb, and the formation of at least one support point by the second lower limb can be executed sequentially, partially overlapped, or synchronously adjusted according to the current posture and contact state. For example, the processor can control the trunk elevation after controlling at least one upper limb to establish temporary auxiliary support contact; it can also simultaneously control the abduction and flexion of the first lower limb during trunk elevation, so that the knee joint or lower limb end of the first lower limb approaches the contact surface more quickly; it can also simultaneously adjust the knee joint angle of the second lower limb during the formation of at least two support points by the first lower limb, so that the first support part of the second lower limb establishes support contact with the contact surface.

[0073] Through the aforementioned process of entering the initial support state based on a prone posture, the legged robot can first use the temporary auxiliary support of at least one upper limb to contact and lift the torso in a prone posture, and then control the two lower limbs to form the initial support state. This allows for reserved movement space for lower limb adjustment while the torso is close to the contact surface, reduces movement interference during lower limb adjustment, and enables the legged robot to form a support foundation jointly participated in by both lower limbs before the start of the standing-up phase 202.

[0074] In some embodiments, the legged robot further includes sensors, and when the instructions are executed by at least one processor, before executing a sequence of standing actions in response to a stand-up trigger instruction, the legged robot also: acquires pose data of the legged robot collected by the sensors; determines, based on the pose data, whether the legged robot is about to fall; and generates a stand-up trigger instruction in response to the legged robot being about to fall.

[0075] In this embodiment, the sensor may include at least one of an inertial measurement unit, a joint encoder, a force sensor, a contact sensor, and a vision sensor. The pose data may include at least one of torso tilt angle, torso angular velocity, torso acceleration, joint angle, joint angular velocity, foot contact state, and support reaction force. The processor can determine whether the legged robot is in an unstable state based on the pose data. For example, when the torso tilt angle relative to the vertical direction continuously increases, the torso angular velocity exceeds a preset angular velocity threshold, the foot support state is abnormal, or the combination of the above parameters meets a preset fall determination condition, it can be determined that the legged robot is about to fall, and a get-up trigger command can be generated. By acquiring the pose data of the legged robot before executing the get-up action sequence and generating a get-up trigger command based on the pose data, the legged robot can promptly enter the get-up control process after experiencing pose instability, reducing the likelihood of the robot remaining in a fallen or low-position unstable state for an extended period. Meanwhile, since the stand-up trigger command is generated based on the actual pose data collected by the sensor, it can adapt to the triggering requirements of different motion tasks, different contact surface conditions and different unstable postures, thereby improving the accuracy and timeliness of the stand-up action sequence triggering.

[0076] In some embodiments, the legged robot further includes an inertial measurement unit disposed on the torso. When the instruction is executed by at least one processor, before executing the standing action sequence in response to a standing trigger instruction, the legged robot further causes the following: to acquire real-time pose data of the torso measured by the inertial measurement unit and to acquire reference pose data in a preset trajectory; to determine the pose difference between the real-time pose data and the reference pose data; and to generate a standing trigger instruction when the pose difference is greater than a preset threshold.

[0077] In this embodiment, the inertial measurement unit (IMU) can be used to measure the torso's attitude angles, angular velocities, and accelerations. Real-time pose data can include at least one of the torso's roll angle, pitch angle, yaw angle, angular velocity, or acceleration. The reference pose data in the preset trajectory can be the expected torso pose data corresponding to the legged robot in the current movement phase, such as preset torso attitude angles, attitude angular velocities, or attitude change ranges in standing, walking, turning, squatting, front flip, back flip, flying kick, or operational actions. The pose difference can be determined based on the angle difference, angular velocity difference, or comprehensive attitude deviation between the real-time pose data and the reference pose data. By setting the IMU on the torso and comparing the real-time pose data with the reference pose data in the preset trajectory, it is possible to directly determine whether the torso pose deviates from the expected pose corresponding to the current movement task. When the pose difference exceeds a preset threshold, it indicates that the legged robot has experienced a significant attitude shift or instability trend. At this time, generating a stand-up trigger command can match the stand-up action sequence with the robot's actual instability state, thereby improving the reliability of the stand-up trigger judgment.

[0078] For highly dynamic movements such as front flips, back flips, and flying kicks, the torso of a legged robot may undergo significant posture changes within a short period. If judgment is based solely on whether the changes in pose data exceed a fixed threshold, normal posture changes during these highly dynamic movements may be misjudged as falls or impending falls, thus falsely triggering a sequence of getting-up movements. This embodiment introduces reference pose data from a preset trajectory, allowing comparison between real-time pose data and the reference pose that should occur during the current movement phase. For example, if a legged robot is performing a front flip, even if the torso posture angle changes significantly, as long as the pose difference between the real-time pose data and the corresponding reference pose data for that movement phase does not exceed a preset threshold, the posture change can be considered within the allowable range of the current movement trajectory, thereby avoiding the misdetection of normal movements as falls.

[0079] In the embodiments of this application, multiple control actions are described for the same action stage. Unless one control action is explicitly specified to be executed before or after another control action, the multiple control actions can be executed in a preset order, or at least partially synchronously or overlappingly.

[0080] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0081] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0082] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0083] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0084] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A legged robot, characterized in that, include: The torso includes an upper torso and hips, with the upper torso and hips rotatably connected; The head, two upper limbs, two lower limbs, and corresponding limb ends are respectively connected to the torso, wherein the two lower limbs are respectively connected to the hip. At least one processor; and, At least one storage medium storing instructions that, when executed by the at least one processor, cause the legged robot to: In response to a stand-up trigger command, a stand-up action sequence is executed, the stand-up action sequence including an initial support phase and a stand-up phase; wherein... The initial support phase includes: controlling the legged robot to enter an initial support state, in which the minimum distance between the head and the contact surface is a first distance, the minimum distance between the hip and the contact surface is a second distance, the sum of the length of the torso and the second distance is a third distance, the ratio of the first distance to the third distance is greater than or equal to 0.65, there are at least two support points between the first lower limb and the contact surface, there is at least one support point between the second lower limb and the contact surface, the second lower limb establishes support contact with the contact surface at least through a first support part, the first surface distance between the first support part and the hip is less than the second surface distance between the lower limb end of the second lower limb and the hip, the knee joint angle of the first lower limb is 30° to 120°, the knee joint angle of the second lower limb is 45° to 150°, and the ratio of the minimum distance between the knee joints of the two lower limbs to the thigh length of the first lower limb is greater than or equal to 1. The standing phase includes: controlling the center of gravity of the legged robot to rise; during the rise of the center of gravity: controlling the upper torso to rotate relative to the hip, wherein the rotation angle of the upper torso relative to the hip is greater than or equal to 20°; controlling the knee joint of the first lower limb to rise away from the contact surface, wherein during the rise of the knee joint of the first lower limb away from the contact surface, the lower limb end of the first lower limb makes support contact with the contact surface; controlling the first support part of the second lower limb to disengage from the contact surface, and controlling the lower limb end of the second lower limb to make support contact with the contact surface.

2. The legged robot according to claim 1, characterized in that, The rising phase further includes: during the rotation of the upper torso relative to the hips, the distance between the distal end of at least one of the upper limbs and the contact surface is greater than the distance between the corresponding elbow joint and the contact surface; or, During the rotation of the upper torso relative to the hip, the distal end of at least one of the upper limbs is controlled to move away from the contact surface.

3. The legged robot according to claim 1, characterized in that, In the initial support state, there is at least one support point located at the knee joint or thigh between the first lower limb and the contact surface; The first supporting part of the second lower limb is located at the knee joint or thigh of the second lower limb.

4. The legged robot according to claim 3, characterized in that, In the initial support state, one support point between the first lower limb and the contact surface is located at the knee joint of the first lower limb, and the other support point between the first lower limb and the contact surface is located at the lower limb end of the first lower limb; the first support part of the second lower limb is the knee joint of the second lower limb.

5. The legged robot according to claim 3, characterized in that, In the initial support state, a plane that intersects the geometrically enclosed area of ​​the thigh, knee joint and calf of the first lower limb is used as the first reference plane, and the angle between the first reference plane and the contact surface is less than or equal to 45°. A plane that intersects the geometrically enclosed area of ​​the thigh, knee joint and calf of the second lower limb is used as a second reference plane, and the angle between the second reference plane and the contact surface is greater than or equal to 45°.

6. The legged robot according to claim 3, characterized in that, In the initial supported state, the angle between the thigh of the first lower limb and the contact surface is 0° to 30°, the angle between the thigh of the second lower limb and the contact surface is 0° to 45°, and the hip is in contact with or separated from the contact surface.

7. The legged robot according to claim 1, characterized in that, In the initial support state, the upper torso faces the first lower limb, so that the upper torso is in a deflected position relative to the hip. The standing-up phase also includes: controlling the upper torso to rotate relative to the hips from the deflected posture to the upright posture; During the standing-up phase, the angle at which the upper torso rotates relative to the hips from the deflected posture to the forward posture is less than or equal to 100°.

8. The legged robot according to claim 4, characterized in that, In the initial supported state, the distal end of the first lower limb establishes supporting contact with the contact surface through the side area of ​​the foot, and the rising phase includes: During the process of the center of mass rising: the upper torso is controlled to rotate relative to the hip; the knee joint of the first lower limb is controlled to rise away from the contact surface, so that the knee joint of the first lower limb is released from the contact surface, and the contact area between the lower limb end and the contact surface is controlled to shift from the side area of ​​the foot to the foot area; after the knee joint of the first lower limb is released from the contact surface, the knee joint of the second lower limb is controlled to be released from the contact surface, and the lower limb end of the second lower limb is controlled to make contact with the contact surface, so that the legged robot enters a bipedal support state.

9. The legged robot according to claim 1, characterized in that, During the initial support phase, the instructions, when executed by the at least one processor, also cause the legged robot to: Based on a supine position, the torso is controlled to rise, and the first lower limb is controlled to detach from the contact surface; after the first lower limb separates from the contact surface, the first lower limb is controlled to cross over the second lower limb and re-establish contact with the contact surface; The first lower limb is controlled to form at least two support points with the contact surface, and the second lower limb is controlled to form at least one support point with the contact surface, so as to enter the initial support state.

10. The legged robot according to claim 1, characterized in that, During the initial support phase, the instructions, when executed by the at least one processor, also cause the legged robot to: Based on the prone position, at least one of the two upper limbs is controlled to establish temporary auxiliary support contact with the contact surface; based on the temporary auxiliary support contact, the torso is raised, and at least two support points are formed between the first lower limb and the contact surface, and at least one support point is formed between the second lower limb and the contact surface, so as to enter the initial support state.

11. The legged robot according to any one of claims 1 to 10, characterized in that, The legged robot also includes sensors, and when the instructions are executed by the at least one processor, prior to executing the sequence of standing actions in response to a standing trigger instruction, the legged robot further causes: Acquire the pose data of the legged robot collected by the sensor; Determine whether the legged robot is about to fall based on the pose data; In response to the legged robot about to fall, the get-up trigger command is generated.

12. The legged robot according to any one of claims 1 to 10, characterized in that, The legged robot further includes an inertial measurement unit disposed on the torso, and when the instruction is executed by the at least one processor, before executing the standing action sequence in response to the standing trigger instruction, the legged robot also causes: The inertial measurement unit acquires the real-time pose data of the torso and the reference pose data in the preset trajectory. Determine the pose difference between the real-time pose data and the reference pose data; When the pose difference is greater than a preset threshold, the get-up trigger command is generated.

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