A foot-type robot

Abstract

This application discloses a legged robot for reducing the center of gravity position during the leg sweeping process and minimizing the impact of hip contact with the ground or joint interference on the leg sweeping action. The application includes: controlling the legged robot to rotate in a first direction based on a preset leg sweeping posture, wherein the preset leg sweeping posture includes: a first distance between the hip and the contact surface of 1mm to 200mm; the first lower limb of the two lower limbs externally rotated relative to the hip, the knee joint angle of the first lower limb of 20° to 90°, the lower limb end of the first lower limb in a foot-side support state, a second distance between the knee joint of the first lower limb and the contact surface of 1mm to 400mm; the ratio of the minimum distance between the knee joint of the first lower limb and the knee joint of the second lower limb of the two lower limbs to the thigh length of the first lower limb is greater than or equal to 1, the knee joint angle of the second lower limb of 110° to 180°, and the minimum distance between the lower limb end of the first lower limb and the hip is less than the minimum distance between the lower limb end of the second lower limb and the hip.

Description

Technical Field

[0001] This application relates to the field of robot control technology, and in particular to a legged robot. Background Technology

[0002] With the development of legged robot mobility, some application scenarios have placed higher demands on the robot's dynamic motion capabilities. For example, in combat training scenarios or action demonstration scenarios, the robot may need to perform low-position sweeping leg movements similar to sweeping legs.

[0003] When performing a low-level sweeping motion, legged robots need to rotate their lower limbs significantly within a height range close to the contact surface. If the legged robot cannot sufficiently lower the height of the sweeping motion, the sweeping trajectory is prone to being too high, preventing the sweeping motion from effectively targeting the opponent's lower limbs or the target's low area. However, since the lower limbs of legged robots are generally composed of rigid links and rotating joints, when the legged robot needs to further lower its body height, the adjustable space of each joint in the lower limbs will also decrease, easily causing some joints to approach their movement limits and restricting the posture coordination between the torso, hips, and lower limbs. These situations make it difficult for the robot to achieve the ideal sweeping height, making it difficult for the robot to lower itself to a height suitable for the sweeping motion. Summary of the Invention

[0004] This application provides a legged robot for lowering the center of gravity position during the leg sweeping process and reducing the impact of hip contact with the ground or joint interference on the leg sweeping action.

[0005] The first aspect of this application provides a legged robot, comprising:

[0006] The torso, including the hips; Two lower limbs and their corresponding extremities 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, the at least one storage medium being encoded with instructions that, when executed by the at least one processor, cause the legged robot to: The legged robot is controlled to rotate in a first direction based on a preset leg-sweeping posture, wherein the first direction is either clockwise or counterclockwise. The preset leg-sweeping posture includes: a first distance between the hip and the contact surface of 1mm to 200mm; a plane intersecting the geometrically enclosed area of ​​the thigh, knee joint, and calf of the first lower limb as a reference plane, the angle between the reference plane and the contact surface being less than or equal to 60°, the knee joint angle of the first lower limb being 20° to 90°, the lower limb end being in a foot-side support state, a second distance between the knee joint of the first lower limb and the contact surface of 1mm to 400mm; the ratio of the minimum distance between the knee joint of the first lower limb and the knee joint of the second lower limb to the thigh length of the first lower limb being greater than or equal to 1, the knee joint angle of the second lower limb being 110° to 180°, and the minimum distance between the lower limb end of the first lower limb and the hip being less than the minimum distance between the lower limb end of the second lower limb and the hip.

[0007] As can be seen from the above technical solutions, this application has the following advantages: In the preset leg-sweeping posture, a first distance of 1mm to 200mm is maintained between the hip and the contact surface. The first lower limb is externally rotated relative to the hip, with a knee joint angle of 20° to 90°, and the lower limb tip is in a foot-side support position. This posture allows the first lower limb to approach the contact surface while bent and externally rotated, utilizing the foot-side area at the lower limb tip for support, thus lowering the robot's center of gravity to a lower position while avoiding the hip touching the ground. Simultaneously, the second lower limb extends away from the first lower limb relative to the hip, with a knee joint angle of 110° to 180°. The minimum distance between the lower limb tip and the hip is less than the minimum distance between the lower limb tip and the hip, resulting in a posture configuration where the robot is supported on one side and extended on the other. Based on this preset leg-sweeping posture, the torso and second lower limb are then controlled to rotate around the lower limb tip of the first lower limb in a first direction. During rotation, the first lower limb maintains low-position support through a smaller knee joint angle and a side-supported stance, while the second lower limb performs a sweeping motion through a larger knee joint angle and an extended posture away from the first lower limb. Based on this method, the legged robot can lower the center of gravity position during the sweeping motion, enabling the sweeping motion to effectively target the opponent's lower limbs or the target's low-position area, and reducing the impact of hip contact with the ground or joint interference on the sweeping motion. Attached Figure Description

[0008] 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.

[0009] 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 control flow for an embodiment of the leg-sweeping robot provided in this application performing a leg-sweeping motion; Figure 3 A schematic diagram of a support state of the legged robot provided in this application under a preset leg sweeping posture; Figure 4 A schematic diagram of the distance relationship of the legged robot provided in this application under a preset leg-sweeping posture; Figure 5 Another distance relationship diagram for the legged robot provided in this application under a preset leg-sweeping posture; Figure 6 A schematic diagram of the control flow for another embodiment of the leg-sweeping robot provided in this application performing a leg-sweeping motion; Figure 7 This is a planar schematic diagram of the supporting polygon formed by a legged robot during the recovery and standing phase. Detailed Implementation

[0010] This application provides a legged robot for lowering the center of gravity position during the leg sweeping process and reducing the impact of hip contact with the ground or joint interference on the leg sweeping action.

[0011] The legged robot provided in this application includes a torso, two upper limbs, two lower limbs, at least one processor, and at least one storage medium. The two upper limbs are each connected to the torso, and the two lower limbs are each connected to the torso. For ease of description, the two upper limbs may be referred to as the first upper limb and the second upper limb, and the two lower limbs may 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.

[0012] Each upper limb includes an upper limb endpiece for establishing supporting contact with the contact surface, and each lower limb includes a lower limb endpiece for establishing supporting contact with the contact surface. Each lower limb also includes a thigh and a lower leg, connected by a knee joint to allow the lower limb to adjust its posture between different support states. It should be noted that the contact surface can be the ground, a platform surface, or other load-bearing surface capable of providing support for the legged robot; the upper limb endpiece can be a hand, a robotic hand, or other end structure capable of establishing supporting contact with the contact surface; the lower limb endpiece can be a foot, a foot actuator, or other end structure capable of establishing supporting contact with the contact surface; this application does not limit the specific endpiece.

[0013] 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.

[0014] In some embodiments, the legged robot can be a humanoid robot, which is a specific implementation of legged robots. For ease of description, the following description mainly uses a humanoid robot as an example. Please refer to [link / reference]. Figure 1 , Figure 1 This illustration shows an overall structural diagram of a humanoid robot, an example of a legged robot in this application. The humanoid robot includes a torso 3 and two upper limbs 1 and two lower limbs 2 connected to the torso 3. In some embodiments, the torso 3 may further include an upper torso 31 and a hip 32, wherein the upper torso 31 supports the upper limbs and head, and the hip 32 connects the two lower limbs and serves as a reference connection structure for lower limb movement. In some embodiments, the upper torso 31 and the hip 32 may be rotatably connected. In other embodiments, the legged robot may also adopt other limb configurations, as long as it can establish supporting contact with the contact surface through the limb ends or limb joints and complete the standing action according to the supporting state switching method of the embodiments of this application, it can be applied to the technical solution of this application.

[0015] Please see Figure 2 , Figure 2A schematic diagram of the control flow for an embodiment of a leg-sweeping motion performed by a leg-mounted robot. The at least one storage medium stores instructions that, when executed by at least one processor, control the coordinated operation of the joint motors of the leg-mounted robot to enable the leg-mounted robot to: 201. Based on a preset leg-sweeping posture, control the legged robot to rotate in a first direction, wherein the first direction is either clockwise or counterclockwise. The preset leg-sweeping posture includes: a first distance between the hip and the contact surface of 1mm to 200mm; a plane intersecting the geometrically enclosed area of ​​the thigh, knee joint, and calf of the first lower limb as a reference plane, the angle between the reference plane and the contact surface being less than or equal to 60°, the knee joint angle of the first lower limb being 20° to 90°, the lower limb end being in a foot-side support state, and a second distance between the knee joint of the first lower limb and the contact surface of 1mm to 400mm; the ratio of the minimum distance between the knee joint of the first lower limb and the knee joint of the second lower limb to the thigh length of the first lower limb being greater than or equal to 1, the knee joint angle of the second lower limb being 110° to 180°, and the minimum distance between the lower limb end of the first lower limb and the hip being less than the minimum distance between the lower limb end of the second lower limb and the hip.

[0016] In this embodiment, the first direction can be determined based on the target direction of the leg-sweeping action. For example, when viewed from above the legged robot towards the contact surface, the first direction can be clockwise; in another embodiment, the first direction can also be counterclockwise. There is a correspondence between the first direction and the selection of the first lower limb. The first lower limb is the lower limb located on the rotation support side when the legged robot rotates in the first direction, and the second lower limb is the lower limb that extends outward relative to the first lower limb and forms the leg-sweeping action. That is, when the legged robot performs the leg-sweeping action in different first directions, the processor can select the left or right lower limb as the first lower limb and select the other lower limb as the second lower limb based on the first direction, so that the lower limb end of the first lower limb can form a foot side support on the contact surface, and the second lower limb can extend in a direction away from the first lower limb and rotate with the legged robot as a whole. In one embodiment, when the left lower limb of the legged robot is used as the first lower limb and the right lower limb as the second lower limb, when viewed from above the legged robot towards the contact surface, the processor controls the legged robot to rotate in a counterclockwise direction. In another implementation, when the right lower limb of the legged robot is used as the first lower limb and the left lower limb as the second lower limb, viewed from above the contact surface, the processor controls the legged robot to rotate clockwise. The processor can determine a first direction based on a preset action sequence, the target leg-sweeping angle, or the position of the target leg-sweeping object relative to the legged robot, and determine the correspondence between the first and second lower limbs based on this first direction. Subsequently, the processor controls the torso, hips, and both lower limbs to rotate as a whole in the first direction, so that the first lower limb maintains support in a low-bent state, and the second lower limb completes the leg-sweeping in a relatively extended state.

[0017] The first distance between the hip and the contact surface can be the minimum distance between the hip and the contact surface along the direction of gravity. It should be noted that the hip refers to the structural area located at the lower end of the torso that connects the two lower limbs, while the thigh joint is a separate, movable connecting joint between the lower limbs and the hip; that is, the hip does not include the thigh joint. This first distance can be from 1mm to 200mm, for example, 1mm, 5mm, 10mm, 20mm, 50mm, 100mm, 150mm, or 200mm. If the first distance is less than 1mm, the gap between the hip and the contact surface is too small, and the hip is prone to unintended contact with the contact surface during rotation, leading to increased rotational resistance and affecting the continuity of the leg-sweeping motion. If the first distance is greater than 200mm, the hip is too high from the contact surface, making it difficult for the legged robot's center of gravity to descend to the low position required for the leg-sweeping motion, thus weakening the effectiveness of the second lower limb in forming the sweeping motion. By limiting the first distance to 1mm to 200mm, the hip can be kept off the ground in the low area near the contact surface, allowing the legged robot to obtain a lower center of gravity position, while reducing the risk of the leg rotation being hindered due to the hip directly touching the ground.

[0018] A reference plane is defined as the plane that intersects the geometrically enclosed area of ​​the thigh, knee, and lower leg of the first lower limb. This reference plane can pass through the thigh, knee, and lower leg of the first lower limb simultaneously. In a preset sweeping leg posture, the processor controls the first lower limb to externally rotate relative to the hip, causing the thigh, lower leg, and knee joint of the first lower limb to tilt as a whole towards the contact surface. At this time, an angle is formed between the reference plane and the contact surface; specifically, this angle is located on the outer side of the thigh of the first lower limb. In the preset sweeping leg posture, the angle between the reference plane and the contact surface is less than or equal to 60°, indicating that the overall structure formed by the thigh, knee, and lower leg of the first lower limb has a significant degree of tilt towards the contact surface. For example, in the preset sweeping leg posture, the angle between the reference plane and the contact surface can be 60°, 50°, 40°, 30°, 20°, or 10°. As this angle decreases, the knee joint of the first lower limb is closer to the contact surface, making it easier for the lower limb's distal end to contact the contact surface with the side of the foot. When the degree of external rotation increases, the knee joint of the first lower limb will deviate further outward from the body.

[0019] The knee joint angle of the first lower limb is between 20° and 90°, for example, it can be 20°, 30°, 45°, 60°, 75°, or 90°. This knee joint angle is the internal angle between the thigh link and the lower leg link of the first lower limb. Limiting the knee joint angle of the first lower limb to between 20° and 90° allows the first lower limb to maintain low-position support while avoiding insufficient joint movement space due to excessive joint flexion.

[0020] The distal end of the first lower limb has a foot region and a side region located to one side of the foot region. The foot region is the bottom surface of the distal end of the lower limb facing the contact surface in a normal standing position; the side region is the edge region located to one side of the foot region. The distal end of the first lower limb is in a side-supported state, specifically meaning that the distal end of the first lower limb establishes supporting contact with the contact surface through at least a portion of the outer edge region of the foot. If the distal end of the first lower limb is supported by the entire sole of the foot against the contact surface, the sole needs to maintain a conforming posture to the contact surface, and the positional freedom of the ankle joint and the distal end of the lower leg will be limited by the foot conforming relationship. In this case, when the first lower limb continues to bend and lowers the hip towards the contact surface, the lower leg and the sole of the first lower limb need to simultaneously satisfy constraints such as knee folding, ankle posture maintenance, and sole conforming, which can easily cause the joints to reach their movement limits, restricting the legged robot from continuing to descend in a sweeping posture. In the preset leg-sweeping posture of this embodiment, the outer edge of the foot serves as the primary load-bearing area at the end of the first lower limb, with the sole of the foot inclined relative to the contact surface. This allows the lower leg of the first lower limb to move laterally and downwards with external rotation and knee flexion, and the knee joint can move closer to the contact surface. The support area formed by the outer edge provides a low-position support reference offset to one side of the sole of the foot for the first lower limb, enabling it to continue bearing the weight of the robot with a greater degree of folding, and preserving posture space for the hip to descend towards the contact surface. Based on this support method, the legged robot can further lower its center of gravity without the hip touching the ground, allowing the second lower limb to extend outwards and participate in the rotational leg-sweeping posture in a low-position posture.

[0021] With the first lower limb in a side-supported position with the foot side down, the second distance between the knee joint and the contact surface can be the minimum distance between the knee joint and the contact surface along the direction of gravity. This second distance can be between 1mm and 400mm, for example, 1mm, 10mm, 30mm, 50mm, 100mm, 200mm, 300mm, or 400mm. If the second distance is less than 1mm, the gap between the knee joint and the contact surface is too small, making it easy for the knee joint to make unintended contact with the contact surface during rotation, thus increasing rotational resistance and affecting the continuity of the sweeping leg movement. If the second distance is greater than 400mm, the knee joint of the first lower limb is too high from the contact surface, making it difficult for the first lower limb to form a low-lying folded support posture close to the contact surface. The hip and center of gravity also cannot descend to the low-lying area required for the sweeping leg movement, thus weakening the low-lying effect of the sweeping leg movement. By limiting the second distance to 1mm to 400mm, a safe clearance can be maintained for the knee joint of the first lower limb in the low region near the contact surface, allowing the first lower limb to provide a lower support reference for the hip when the foot is supported on the side, while reducing the risk of rotational obstruction caused by direct contact of the knee joint with the ground.

[0022] The ratio of the minimum distance between the knee joint of the first lower limb and the knee joint of the second lower limb to the thigh length of the first lower limb is greater than or equal to 1. The thigh length of the first lower limb is the length of the link between the connecting end of the first lower limb and the hip and the knee joint of the first lower limb. By ensuring that 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 second lower limb can maintain sufficient lateral extension distance relative to the first lower limb, which is beneficial for providing a larger sweeping radius and rotational inertia during robot rotation. As the ratio of the minimum distance between the knee joints of the two lower limbs to the thigh length of the first lower limb increases, the sweeping range covered by the second lower limb during rotation increases. The knee joint angle of the second lower limb is between 110° and 180°, for example, 110°, 120°, 130°, 145°, 160°, 175°, and 180°. If the knee angle of the second lower limb is less than 110°, the second lower limb is excessively bent, reducing the distance between the lower limb's distal end and the hip, thus shortening the sweeping radius and making it difficult to achieve sufficient coverage. Simultaneously, excessive folding of the second lower limb in the lower region near the contact surface can cause the knee or lower leg to occupy a large amount of space, increasing the risk of interference with the contact surface or other limbs. If the knee angle of the second lower limb is greater than 180°, the second lower limb exceeds its normal extended state, easily approaching or exceeding the mechanical limit of the knee joint, increasing the risk of joint damage. By limiting the knee angle of the second lower limb to between 110° and 180°, the second lower limb can maintain a relatively extended state during the sweeping process, creating a larger distance between the lower limb's distal end and the hip, thereby increasing the sweeping radius and coverage, while preventing damage to the knee joint structure from excessive extension.

[0023] The minimum distance between the distal end of the first lower limb and the hip is less than the minimum distance between the distal end of the second lower limb and the hip. Both the minimum distance between the distal end of the first lower limb and the hip, and the minimum distance between the distal end of the second lower limb and the hip, should be measured using the same method. This distance relationship dictates that the distal end of the first lower limb is closer to the hip, creating a folded support, while the distal end of the second lower limb is further away from the hip, creating an extended sweeping motion.

[0024] Please see Figure 3 , Figure 3This diagram illustrates a support state for a legged robot in a preset sweeping posture. In the corresponding embodiment, the legged robot is in a low-position posture close to contact surface A, with a first distance maintained between the hip and contact surface A, allowing the hip to approach but not support the contact surface A. The first lower limb rotates outward relative to the hip, and with the knee joint bent, the corresponding lower limb tip contacts contact surface A with the side of the foot, thus forming low-position support on contact surface A. Because the lower limb tip uses the side of the foot for support, the knee joint of the first lower limb can get closer to contact surface A, causing the center of gravity of the hip and the legged robot to drop to a low position suitable for performing the sweeping motion. The second lower limb extends away from the first lower limb relative to the hip, creating a larger gap between the lower limb tip and the hip, thus forming a sweeping motion when the legged robot rotates around the area near the lower limb tip of the first lower limb. Reference plane B can be determined based on the thigh, knee joint, and lower leg of the first lower limb. For example, at least one reference point can be selected within the geometrically enclosed regions of the thigh, knee joint, and lower leg, respectively, and a plane that can pass through all of these reference points can be used as reference plane B. It should be noted that... Figure 3 Only one implementation of the preset leg sweeping posture is shown. In other embodiments, the left-right correspondence between the first lower limb and the second lower limb can be interchanged according to different first directions. As long as the legged robot satisfies the posture relationship of the first lower limb with the foot side supported, the first lower limb with low bending, and the second lower limb with the second lower limb extended away from the first lower limb, it can be used as the preset leg sweeping posture of this application.

[0025] Please see Figure 4 , Figure 4 This is a schematic diagram illustrating the distance relationship of a legged robot in a preset leg-sweeping posture. Contact surface A can be the ground or other supporting surface on which the legged robot is located. Figure 4 In the preset leg sweep posture shown, the thigh of the first lower limb is externally rotated relative to the hip, causing the thigh, knee joint, and lower leg of the first lower limb to tilt towards the contact surface A. An angle α is formed between the reference plane B and the contact surface A. This angle α can be an acute angle between the reference plane B and the contact surface A, meaning it can be marked on the outer side of the thigh of the first lower limb. When the angle α decreases, the tilt of the reference plane B relative to the contact surface A increases, indicating that the thigh, knee joint, and lower leg of the first lower limb are closer to the contact surface A. At this time, the knee joint of the first lower limb can be closer to the contact surface A, and the lower limb tip can more easily establish supporting contact with the contact surface A using the side area of ​​the foot.

[0026] In this embodiment, under the preset leg-sweeping posture, a first distance of 1mm to 200mm is maintained between the hip and the contact surface. The first lower limb is externally rotated relative to the hip, with a knee joint angle of 20° to 90°, and the lower limb tip is in a foot-side support state. With this posture, the first lower limb can approach the contact surface in a bent and externally rotated state, utilizing the foot-side area at the lower limb tip for support, thereby lowering the robot's center of gravity to a lower position while avoiding the hip touching the ground. Simultaneously, the second lower limb extends away from the first lower limb relative to the hip, with a knee joint angle of 110° to 180°. The minimum distance between the lower limb tip of the first lower limb and the hip is less than the minimum distance between the lower limb tip of the second lower limb and the hip, resulting in a posture configuration where the robot is supported on one side and extended on the other. Based on the above preset leg-sweeping posture, the torso and second lower limb are then controlled to rotate around the lower limb tip of the first lower limb in a first direction. During rotation, the first lower limb maintains low-lying support through a smaller knee joint angle and a side-supported position on the foot, while the second lower limb performs a sweeping motion through a larger knee joint angle and an extended posture away from the first lower limb. Based on this method, the legged robot can lower the center of gravity position during the sweeping process and reduce the impact of hip contact with the ground or joint interference on the sweeping motion.

[0027] In some embodiments, the first distance is less than the second distance, and the third distance between the knee joint of the second lower limb and the contact surface is less than the second distance between the knee joint of the first lower limb and the contact surface; the first distance is 5mm to 100mm, and the second distance is 10mm to 200mm; the knee joint angle of the first lower limb is 30° to 75°, and the knee joint angle of the second lower limb is 150° to 180°; during the process of controlling the legged robot to rotate in the first direction based on the preset leg sweeping posture, the angle of controlling the legged robot to rotate in the first direction is greater than or equal to 100°.

[0028] In this embodiment, please refer to Figure 4 , Figure 4 This is a schematic diagram of the distance relationship of a legged robot in a preset leg-sweeping posture. Figure 4In this design, the first distance d1 is the minimum distance along the direction of gravity between the hip and the contact surface, and the second distance d2 is the minimum distance along the direction of gravity between the knee joint of the first lower limb and the contact surface. The first distance d1 is smaller than the second distance d2, indicating that the hip is closer to the contact surface than the knee joint of the first lower limb. Based on this positional relationship, the first lower limb forms a bent support in a side-supported state, allowing the hip to be lowered to below the knee joint of the first lower limb or relatively closer to the contact surface, thus placing the overall center of gravity of the legged robot in a lower position. If the first distance d1 gradually decreases, the hip gradually moves closer to the contact surface, and the height of the legged robot's center of gravity decreases accordingly. The first distance d1 is between 5mm and 100mm, for example, it can be 5mm, 10mm, 20mm, 30mm, 50mm, 80mm, or 100mm. By further limiting the first distance d1 to between 5mm and 100mm, a more stable and safe clearance can be maintained for the hip in the lower region close to the contact surface, thus achieving a better balance between lowering the center of gravity and preventing the hip from touching the ground. The second distance d2 is between 10mm and 200mm, for example, it can be 10mm, 20mm, 50mm, 80mm, 100mm, 150mm, or 200mm. By further limiting the second distance d2 to between 10mm and 200mm, the knee joint of the first lower limb can maintain a reasonable ground clearance in the area near the contact surface, allowing the first lower limb to form a stable low-position support in the foot-side support state. Since the first distance d1 is smaller than the second distance d2, the hip is closer to the contact surface than the knee joint of the first lower limb. This positional relationship indicates that the first lower limb forms a low-position support through the foot-side area in a flexed and externally rotated state, and the hip is pressed down to a region closer to the contact surface. Based on the range of the first distance d1 and the second distance d2 in this embodiment, the legged robot can form a posture suitable for low-center-of-gravity leg sweeping while keeping the hip off the ground and the knee joint of the first lower limb maintaining a safe clearance.

[0029] The third distance d3 is the minimum distance along the direction of gravity between the knee joint of the second lower limb and the contact surface. The second distance d2 is the minimum distance along the direction of gravity between the knee joint of the first lower limb and the contact surface. The third distance d3 is smaller than the second distance d2, indicating that the knee joint of the second lower limb is closer to the contact surface than the knee joint of the first lower limb. Based on this positional relationship, the second lower limb can form a lower sweeping trajectory, while the knee joint of the first lower limb remains relatively elevated, reducing the risk of the first lower limb knee joint touching the ground during support rotation. The knee joint angle of the first lower limb is 30° to 75°, for example, 30°, 45°, 60°, or 75°. By further limiting the knee joint angle of the first lower limb to 30° to 75°, the first lower limb can maintain sufficient flexion while avoiding excessive folding and damage to the joint structure, in order to cooperate with the side support of the foot to lower the hip and center of gravity position. The knee joint angle of the second lower limb is between 150° and 180°, for example, it can be 150°, 160°, 170°, 175° or 180°. By further limiting the knee joint angle of the second lower limb to 150° to 180°, the second lower limb can maintain a large extended length during the leg sweeping process, allowing the legged robot to form a large leg sweeping range in a low center of gravity state, while reducing the risk of joint damage caused by excessive backward extension of the second lower limb.

[0030] During the process of controlling the legged robot to rotate in a first direction based on a preset sweeping posture, the processor controls the legged robot to rotate in the first direction by an angle greater than or equal to 100°. The first direction can be clockwise or counterclockwise, and the rotation angle can be the cumulative angle by which the projection of the legged robot's torso, hips, or a preset body reference axis onto the contact surface rotates along the first direction relative to the initial direction. Alternatively, it can be the change in the overall orientation of the legged robot relative to its initial orientation under the preset sweeping posture. In some embodiments, the rotation angle can be 100°, 120°, 150°, 180°, 240°, 270°, or 360°. When the angle of rotation of the legged robot in the first direction is less than 100°, the sweeping coverage area formed by the second lower limb near the contact surface is relatively small, the overall rotation amplitude of the robot is insufficient, and it is difficult to fully utilize the sweeping radius and inertial effect formed after the second lower limb extends. By controlling the legged robot to rotate at an angle greater than or equal to 100° in the first direction, the legged robot can form a larger overall rotation amplitude under the preset leg sweeping posture, so that the second lower limb can form continuous movements with the rotation of the hip and torso, thereby expanding the effective coverage of the leg sweeping movement.

[0031] In some embodiments, the legged robot further includes two upper limbs connected to the torso and corresponding limb ends. The two upper limbs include a first upper limb and a second upper limb. The first upper limb includes a first connecting end and is connected to the torso through the first connecting end. The second upper limb includes a second connecting end and is connected to the torso through the second connecting end. The first upper limb and the first lower limb are located on the same side of the torso, and the second upper limb and the second lower limb are located on the same side of the torso. The preset leg sweeping posture further includes: the minimum distance between the knee joint of the first lower limb and the first connecting end is a fifth distance, and the minimum distance between the knee joint of the second lower limb and the second connecting end is a sixth distance. The ratio of the sixth distance to the fifth distance is 1.5 to 4.0.

[0032] In this embodiment, please refer to Figure 5 , Figure 5 This is another schematic diagram of the distance relationship for a legged robot in a preset leg-sweeping posture. Figure 5 In this design, the first connecting end can be the joint center, pivot center, or mounting center connecting the first upper limb to the torso, for example, the shoulder joint center of the first upper limb. The second connecting end can be the joint center, pivot center, or mounting center connecting the second upper limb to the torso, for example, the shoulder joint center of the second upper limb. The fifth distance d5 is the minimum distance between the knee joint of the first lower limb and the first connecting end, and the sixth distance d6 is the minimum distance between the knee joint center of the second lower limb and the second connecting end. The fifth distance d5 and the sixth distance d6 use the same measurement benchmark, and the ratio between the two represents the degree of folding and unfolding of the two limbs of the legged robot. In the preset sweeping leg posture, the first lower limb is used to form side support of the foot, and the knee joint of the first lower limb is close to the torso area on the side where the first connecting end is located, so that the fifth distance d5 is in a smaller state. The second lower limb is used to form an outwardly extending sweeping leg limb, and the knee joint of the second lower limb unfolds away from the torso relative to the second connecting end, so that the sixth distance d6 is greater than the fifth distance d5. Therefore, the ratio of the sixth distance d6 to the fifth distance d5 can reflect the degree of asymmetry of the two limbs under the preset leg sweep posture.

[0033] The ratio of the sixth distance d6 to the fifth distance d5 is between 1.5 and 4.0, for example, it can be 1.5, 2.0, 2.5, 3.0, 3.5, or 4.0. If the ratio of the sixth distance d6 to the fifth distance d5 is less than 1.5, the knee joint of the second lower limb is not sufficiently extended relative to the second connecting end on the same side, or the knee joint of the first lower limb is not sufficiently folded relative to the first connecting end on the same side, resulting in an indistinct asymmetric posture between the two limbs of the legged robot. In this case, it is difficult to form a compact low-profile support configuration on the side where the first lower limb is located, and it is also difficult to form a sufficiently extended sweeping leg configuration on the side where the second lower limb is located, thus limiting the sweeping leg radius and sweeping leg coverage. If the ratio of the sixth distance d6 to the fifth distance d5 is greater than 4.0, the knee joint of the second lower limb is excessively far away from the second connecting end, or the knee joint of the first lower limb is excessively close to the first connecting end, resulting in an excessively large difference in posture between the two limbs of the legged robot. In this scenario, the extension range of the second lower limb may approach the upper limit of the joint's range of motion, and the retraction degree of the first lower limb may be excessive, easily increasing the structural load on the hip joint, knee joint, and trunk connection area, and making posture control of the legged robot more difficult during low-position rotation. By limiting the ratio of the sixth distance d6 to the fifth distance d5 to between 1.5 and 4.0, the side containing the first lower limb can maintain a relatively retracted low-position support configuration, while the side containing the second lower limb can maintain a relatively extended sweeping leg configuration. This ratio range can create a better posture coordination between the low-position support of the first lower limb and the outward sweeping leg of the second lower limb, allowing the legged robot to lower its center of gravity while maintaining the outward extension of the second lower limb and its participation in the rotational sweeping leg, thereby improving the execution range and posture stability of the low-position sweeping leg movement.

[0034] In some embodiments, the legged robot further includes a first upper limb connected to the torso and a corresponding limb end, the first upper limb and the first lower limb being located on the same side of the torso: the ratio of the minimum distance between the elbow joint of the first upper limb and the torso to the length of the upper arm of the first upper limb is 0.5 to 1.

[0035] In this embodiment, the first upper limb may include an upper arm, forearm, and elbow joint. One end of the upper arm is connected to the torso, and the other end is connected to the forearm via the elbow joint. The end of the forearm away from the elbow joint can be connected to the end of the upper limb. The length of the upper arm of the first upper limb is the length of the link between the end of the first upper limb connected to the torso and the elbow joint of the first upper limb. In the preset sweeping leg posture, the first lower limb is externally rotated relative to the hip and is in a bent support state. The knee joint and lower leg of the first lower limb are close to the same side of the torso. If the elbow joint of the first upper limb is too close to the torso, the first upper limb is prone to spatial interference with the first lower limb on the same side, affecting the external rotation and folding support of the first lower limb. By keeping a certain distance between the elbow joint of the first upper limb and the torso, the first upper limb can extend outward to the torso, providing space for the bending and external rotation of the first lower limb, so that the first lower limb can stably form a foot side support in a low posture.

[0036] The ratio of the minimum distance between the elbow joint of the first upper limb and the torso to the length of the upper arm is 0.5 to 1, for example, 0.5, 0.6, 0.7, 0.8, 0.9, or 1. As this ratio gradually increases, the elbow joint of the first upper limb moves further away from the torso, enhancing the avoidance capability of the first upper limb over the first lower limb, and correspondingly increasing the range of motion of the first lower limb during low-position folding and external rotation. By limiting the ratio of the minimum distance between the elbow joint of the first upper limb and the torso to the length of the upper arm to 0.5 to 1, legged robots of different sizes can be adapted, allowing the first upper limb to form a relatively abducted avoidance posture in a preset leg-sweeping posture, reducing the probability of structural interference between the first upper limb and the first lower limb.

[0037] In some embodiments, the legged robot further includes a first upper limb connected to the torso and a corresponding limb end, the first upper limb and the first lower limb being located on the same side of the torso; when the instruction is executed by at least one processor, during the process of controlling the legged robot to rotate in a first direction based on a preset leg sweeping posture, the legged robot: controls the upper limb end of the first upper limb to maintain contact with the contact surface, and controls the lower limb end of the second lower limb to maintain contact with the contact surface.

[0038] In this embodiment, when the legged robot rotates in the first direction based on a preset leg-sweeping posture, the processor can control the first upper limb to lower towards the contact surface, ensuring that the tip of the first upper limb remains in contact with the contact surface. This contact can be a sliding contact or an intermittent contact. Maintaining contact between the tip of the first upper limb and the contact surface prevents additional posture disturbances caused by the first upper limb swinging in mid-air. Simultaneously, it provides additional posture constraints for the legged robot; when the robot tends to tilt during the leg-sweeping process, the tip of the first upper limb can promptly absorb part of the load, thereby reducing the risk of further tipping. The tip of the second lower limb also maintains contact with the contact surface, which can be a sliding contact or an intermittent contact. Since the second lower limb extends away from the first lower limb relative to the hip, the tip of the second lower limb can form a leg-sweeping trajectory during rotation. By keeping the tip of the second lower limb in contact with the contact surface, the leg-sweeping height of the second lower limb can be kept near the contact surface, thereby improving the coverage effect of the ground-hugging leg-sweeping motion.

[0039] Specifically, the processor can control the normal force between the first and second upper limb ends and the contact surface to be lower than a preset support force threshold, based on force sensors or joint torque feedback located at the ends of the first and second lower limbs. This allows the first and second upper limb ends to slide along the contact surface while reducing the resistance to overall rotation caused by the contact. By controlling the upper limb ends and the lower limb ends to maintain contact with the contact surface, the legged robot can reserve two contact points that can quickly participate in support, while using the side of the first lower limb foot as the main support. This control method can improve the fault tolerance during the low center of gravity leg sweeping process, enabling the legged robot to establish auxiliary support in time when posture deviation occurs during rotation, thereby maintaining body stability.

[0040] In some embodiments, when the instructions are executed by at least one processor, during the process of controlling the legged robot to rotate in a first direction based on a preset leg sweeping posture, the legged robot is controlled to: rotate in the first direction to a first threshold angle, and during the rotation to the first threshold angle, control the lower limb end of the first lower limb to maintain a foot side support state, and during the rotation, control the actual force point between the lower limb end of the first lower limb and the contact surface to dynamically move along the lateral contour of the lower limb end of the first lower limb; after the legged robot rotates beyond the first threshold angle, control the contact area between the lower limb end of the first lower limb and the contact surface to switch from the foot side area to the foot area.

[0041] In this embodiment, the first threshold angle is used to divide the low-position rotation phase and the rotation termination phase during the leg-sweeping rotation process. The first threshold angle can be determined based on the target amplitude of the leg-sweeping motion, the robot's current angular velocity, the support state of the first lower limb, or the friction conditions of the contact surface. For example, the first threshold angle can be 90°, 110°, 150°, 180°, 210°, or 270°. When the first threshold angle is small, the legged robot can enter the rotation termination phase earlier, which is suitable for scenarios where the leg-sweeping amplitude is small or a quick stop is required; when the first threshold angle is large, the legged robot can maintain low-position rotation for a longer period of time, which is suitable for scenarios requiring a larger leg-sweeping coverage area.

[0042] During the rotation of the legged robot in the first direction to the first threshold angle, the distal end of the first lower limb maintains a side-supported state. In this phase, the distal end of the first lower limb uses the side area of ​​the foot as its primary support area. Since the sole of the foot does not need to be fully in contact with the contact surface, the first lower limb can provide low-level support in a flexed and externally rotated posture. The second lower limb rotates with the torso in the first direction and performs a sweeping motion. During rotation, the actual force point between the distal end of the first lower limb and the contact surface can be understood as the location where the contact surface applies the main supporting reaction force to the distal end of the first lower limb, or as the equivalent location where the distal end of the first lower limb currently bears the main normal force or frictional force. As the legged robot rotates around the area near the distal end of the first lower limb, the torso posture, the posture of the first lower limb, and the direction of the contact force continuously change. The actual force point can dynamically move along the lateral contour of the distal end of the first lower limb. For example, the actual force point can gradually move from the heel side to the arch side, and then to the forefoot side or the toe side. This dynamic movement process allows the side-foot support state to adapt to the rotational posture changes of the legged robot, reducing the posture impact caused by sudden changes in the force point. Furthermore, by shifting the actual force point from the heel side to the toe side, the distal end of the first lower limb can gradually approach the contact posture of the foot area while maintaining side-foot support, providing a transitional condition for the subsequent switch from side-foot support to foot support. Therefore, the contact area switching process is smoother, reducing the impact generated when directly switching from side-foot support to foot support.

[0043] After the legged robot rotates beyond a first threshold angle, the processor controls the contact area between the distal end of the first lower limb and the contact surface to switch from the side of the foot to the sole. This sole area can be the bottom region of the distal end of the first lower limb facing the contact surface. Compared to the side of the foot, the sole area allows for a larger contact area and generates greater frictional resistance. Based on this contact area switch, the legged robot can reduce the angular velocity of its rotation around the area near the distal end of the first lower limb, or gradually stop its leg-sweeping rotation. It should be noted that switching the contact area between the distal end of the first lower limb and the contact surface from the side of the foot to the sole is primarily used to reduce the angular velocity of the legged robot during the leg-sweeping process or to stop its rotation. After completing this contact area switch, the legged robot can maintain a low-lying posture or perform a standing motion in a subsequent action sequence. In some embodiments, the processor can gradually increase the knee joint angle between the first and second lower limbs during the contact area switch, causing the center of gravity of the legged robot to gradually rise, thus providing a posture basis for subsequent standing.

[0044] In some embodiments, when the instruction is executed by at least one processor, during the process of controlling the legged robot to rotate in a first direction based on a preset leg-sweeping posture, the legged robot: in response to the stop leg-sweeping instruction, controls the contact area between the lower limb end and the contact surface to switch from the side area of ​​the foot to the foot area.

[0045] In this embodiment, in addition to controlling the contact area between the distal end of the first lower limb and the contact surface to switch from the side of the foot to the sole area when the rotation exceeds a first threshold angle, the leg-sweeping robot can also control the contact area between the distal end of the first lower limb and the contact surface to switch from the side of the foot to the sole area based on a stop sweeping command. The stop sweeping command can be generated by a preset action sequence, or by an external control device, a remote control command, or the robot's internal control program. For example, when the leg-sweeping robot detects that the current angular velocity is lower than a preset angular velocity threshold, detects that the posture deviation exceeds a preset posture threshold, or detects that the contact surface conditions do not meet the requirements for continuing to sweep the leg, the processor can generate a stop sweeping command. In response to the stop sweeping command, the processor controls the contact area between the distal end of the first lower limb and the contact surface to gradually transition from the side of the foot to the sole area, increasing the contact area between the sole area and the contact surface. As the contact area increases, a greater frictional effect can be formed between the distal end of the first lower limb and the contact surface, thereby reducing the angular velocity of the leg-sweeping robot rotating around the area near the first lower limb. In some implementations, after the contact area switches from the side of the foot to the foot itself, the legged robot can maintain a low posture to await the next action command; alternatively, it can continue to perform subsequent recovery actions. These subsequent recovery actions may include adjusting the distal ends of both lower limbs to a foot-supported position, correcting the torso posture, or gradually raising the center of gravity. Thus, the stop-sweep command can serve as an active stopping condition for the sweeping action, enabling the legged robot to achieve rotational deceleration or stop by switching the contact area of ​​the distal end of the first lower limb when it needs to stop the sweeping action.

[0046] In some embodiments, the foot side of the lower limb of the first lower limb is made of metal.

[0047] In this embodiment, the foot side area of ​​the first lower limb needs to bear the load of the machine body on the contact surface and may experience sliding friction with the rotation of the legged robot, making it susceptible to compression, impact, and wear. By making the foot side of the lower limb end of the first lower limb a metal material, the structural strength and wear resistance of the foot side area can be improved, allowing it to maintain a more stable shape and contact state during multiple leg sweeping movements. The metal material can include aluminum alloy, stainless steel, titanium alloy, or other metal materials with high wear resistance, and is not specifically limited here. The foot side can be made entirely of metal, or it can have a metal edging, metal insert, or metal wear-resistant strip. This metal material area can cover at least a portion of the heel side, arch side, forefoot side, or toe side. Thus, when the actual force point between the lower limb end of the first lower limb and the contact surface dynamically moves along the foot side contour, the actual force point can always fall within the metal material area with high wear resistance, thereby reducing the risk of contact point instability caused by local wear. In some implementations, the metal area on the side of the foot can be made of a different material than the foot area. The metal area on the side of the foot is used to accommodate lateral support and sliding friction during the leg sweep rotation, while the foot area can be made of rubber, polyurethane, or other anti-slip materials to increase the friction between the foot and the contact surface after the contact area switches from the side of the foot to the foot area. With the above material configuration, the lower limb tip of the first lower limb can maintain good wear resistance during the side-foot support phase and achieve better deceleration and stability during the foot support phase.

[0048] In some embodiments, the legged robot further includes a second upper limb connected to the torso and a corresponding limb end, the second upper limb and the first lower limb being located on different sides of the torso; when the instruction is executed by at least one processor, before entering the preset leg sweeping posture, the legged robot is also instructed to: control the torso to rotate in a second direction opposite to the first direction, wherein the second direction is the other of a clockwise direction and a counterclockwise direction, and control the elbow joint of the second upper limb to gradually move away from the torso; control the first lower limb and / or the second lower limb to move in a direction away from each other, so as to increase the distance between the lower limb end of the first lower limb and the lower limb end of the second lower limb; and reduce the knee joint angle between the first lower limb and the second lower limb, so as to lower the center of mass of the legged robot.

[0049] In this embodiment, please refer to Figure 6 , Figure 6This is a schematic diagram of the control flow for another embodiment of a leg-sweeping motion performed by a leg-mounted robot. The process before entering the preset leg-sweeping posture can be considered as the leg-sweeping power-accumulation stage 601, and controlling the leg-mounted robot to rotate in a first direction based on the preset leg-sweeping posture can be considered as the leg-sweeping stage 602. The first direction is the direction in which the leg-mounted robot will subsequently perform the leg-sweeping rotation, and the second direction is the opposite direction to the first direction. The processor can first control the torso to rotate in the second direction in the leg-sweeping power-accumulation stage 601. Subsequently, when the leg-mounted robot enters the preset leg-sweeping posture and rotates in the first direction, the torso can rotate back along the first direction, thereby providing greater rotational momentum for the subsequent leg-sweeping motion.

[0050] During the process of controlling the torso to rotate in the second direction, the processor can also control the elbow joint of the second upper limb to gradually move away from the torso. Since the second upper limb and the first lower limb are located on opposite sides of the torso, when the elbow joint of the second upper limb moves away from the torso, the limb posture on the side where the second upper limb is located can be extended outwards. This extension action can, on the one hand, coordinate with the reverse rotation of the torso to adjust the body posture, and on the other hand, allow the legged robot to form a more obvious body extension state before entering the preset leg-sweeping posture. As the elbow joint of the second upper limb gradually moves away from the torso, the mass distribution of the second upper limb shifts to the outside of the torso, and the upper body posture of the legged robot is adjusted accordingly, which is beneficial for the subsequent backflip of the torso in the first direction and for driving the second lower limb to participate in the leg-sweeping rotation. The processor can also control at least one of the first and second lower limbs to move in a direction away from each other, thereby increasing the distance between the lower limb ends of the first and second lower limbs. This distance can be the straight-line distance between a preset reference point at the lower limb end of the first and second lower limbs. As the distance between the legs gradually increases, the two lower limbs gradually extend relative to the hips, and the legged robot transitions from a relatively tucked-in posture to an extended posture suitable for low-level leg sweeping. The distal end of the first lower limb can gradually move to a position suitable for forming side support of the foot, and the distal end of the second lower limb can gradually move away from the first lower limb, thereby providing space for the subsequent formation of the extended leg sweeping posture of the second lower limb. In some embodiments, the movement of the first lower limb away from the second lower limb can be controlled, as can the movement of the second lower limb away from the first limb, or the movement of both lower limbs away from each other can be controlled simultaneously.

[0051] While increasing the distance between the ends of the two lower limbs, the processor can also reduce the knee angle between the first and second lower limbs, causing the center of gravity of the legged robot to decrease. A decrease in the knee angle indicates a decrease in the angle between the thigh and lower leg links of the corresponding lower limb, allowing the lower limb to gradually transition from a relatively extended state to a bent state. As the knee angle of the first lower limb decreases, it can gradually assume a low-profile support posture, lowering the hip towards the contact surface. As the knee angle of the second lower limb decreases, the overall height of the legged robot further decreases, and the second lower limb can also extend outwards in the area close to the contact surface. Thus, the center of gravity of the legged robot can gradually descend from a higher region to a lower region suitable for performing leg-sweeping movements.

[0052] In some implementations, the processor can sequentially execute control steps such as reverse trunk rotation, second upper limb extension, increasing the distance between the ends of the two lower limbs, and decreasing the knee joint angle according to a preset timing sequence. Alternatively, the above actions can be executed with at least partial overlap. For example, while the trunk rotates in the second direction, the elbow joint of the second upper limb can be controlled to move away from the trunk; while the distance between the ends of the two lower limbs increases, the knee joint angle of the two lower limbs can be decreased simultaneously. By making the above actions continuous, the legged robot can complete reverse force accumulation, lower limb extension, and center of gravity descent before entering the preset leg sweeping posture. This allows the legged robot to transition more smoothly from any posture to the preset leg sweeping posture, and provides a lower center of gravity position and a larger initial rotational condition when rotating in the first direction based on the preset leg sweeping posture.

[0053] In some embodiments, when the instructions are executed by at least one processor, after controlling the legged robot to rotate in the first direction based on a preset leg-sweeping posture, the legged robot is further controlled to: restore the lower limb ends of the first lower limb and the lower limb ends of the second lower limb to the foot-supported state, and control the center of mass of the legged robot to fall within the support polygon formed by the lower limb ends of the two lower limbs on the contact surface; increase the knee joint angle between the first lower limb and the second lower limb, so as to raise the center of mass of the legged robot.

[0054] In this embodiment, please refer to Figure 6 After the legged robot rotates in the first direction based on a preset leg-sweeping posture, it enters the standing recovery phase 603. This standing recovery phase 603 can be executed after the legged robot completes the preset leg-sweeping angle, after the legged robot's rotational angular velocity decreases to a preset angular velocity threshold, or after the legged robot responds to a stop leg-sweeping command. In the standing recovery phase 603, the legged robot gradually transitions from a low-position leg-sweeping posture to a foot-supported posture capable of stably bearing the robot's weight.

[0055] The return of the first lower limb to a foot-supported state means that the lower limb gradually switches from support on the side of the foot to support on the sole. The return of the second lower limb to a foot-supported state means that the second lower limb gradually retracts from a sweeping, extended position to a position suitable for bearing the body weight, establishing support contact between the sole and the contact surface. During the sweeping motion, the second lower limb can maintain relative extension and move close to the contact surface; during the return to a standing position, the processor controls the coordinated adjustment of the hip, knee, and ankle joints of the second lower limb, moving the lower limb from the end of the sweeping trajectory to the target landing area. After the lower limb of the second lower limb forms a foot-supported position with the contact surface, the first and second lower limbs can jointly bear the body weight. After the lower limb ends of the first and second lower limbs return to the foot support state and the center of mass falls within the support polygon, the processor can increase the knee joint angle between the first and second lower limbs. As the knee joint angle between the two lower limbs gradually increases, the two lower limbs gradually extend from the bent state, and the hips and torso rise away from the contact surface, and the center of mass of the legged robot moves upward accordingly.

[0056] Please see Figure 7 , Figure 7 This is a planar schematic diagram of the supporting polygon formed by a legged robot during the recovery and standing phase. Figure 7 In the illustrated embodiment, the distal end of the first lower limb and the contact surface form a support region 701 for the first lower limb, and the distal end of the second lower limb and the contact surface form a support region 702 for the second lower limb. The support region 701 of the first lower limb and the support region 702 of the second lower limb together define a support polygon 700.

[0057] Taking the understanding that the supporting polygon is jointly determined by the legged robot and the supporting regions of the contact surface as an example, convex hull calculations can be performed on the outer boundaries of the supporting regions 701 of the first lower limb and 702 of the second lower limb. The smallest convex hull closed polygon, including all supporting points, is taken as the supporting polygon 700. At this time, the supporting polygon 700 covers the supporting regions 701 of the first lower limb, 702 of the second lower limb, and the area enclosed by the outer boundaries of the convex hulls between the two supporting regions. When the projection point of the legged robot's center of mass on the contact surface along the direction of gravity is located within the supporting polygon 700, it can be considered that the center of mass of the legged robot falls within the supporting polygon formed by the lower limb ends of the two lower limbs on the contact surface.

[0058] Taking the understanding that a supporting polygon is constructed from supporting points in a supporting region as an example, at least three supporting points can be selected from the supporting region 701 of the first lower limb and the supporting region 702 of the second lower limb, and a supporting polygon 700 can be constructed based on the selected supporting points. For example, two supporting points can be selected from the supporting region 701 of the first lower limb and at least one supporting point can be selected from the supporting region 702 of the second lower limb. After connecting the selected supporting points, a convex-edge supporting polygon can be formed, and this convex-edge supporting polygon can be used as the supporting polygon 700. Since both the supporting region 701 of the first lower limb and the supporting region 702 of the second lower limb have a certain area, there are many selectable supporting points, and different combinations of supporting points can form different convex-edge supporting polygons.

[0059] In some embodiments, when the projection point of the center of mass on the contact surface along the direction of gravity lies within the support polygon 700 calculated from the outer boundary convex hull of the support region 701 of the first lower limb and the support region 702 of the second lower limb, the center of mass can be considered to fall within the support polygon 700. In other embodiments, when the projection point of the center of mass lies within any convex edge support polygon constructed from selected support points, the center of mass can also be considered to fall within the support polygon 700. Based on the above methods, the processor can determine whether the center of mass of the legged robot is within a stable support range after the two lower limbs regain foot support, and accordingly control the two lower limbs to continue extending to lift the center of mass.

[0060] By controlling the lower limbs to return to a foot-supported state after the leg sweep rotation, and ensuring the robot's center of mass falls within the support polygon formed by the lower limbs, the legged robot can switch from a high-speed dynamic leg sweep to a stable support state. Subsequently, by increasing the knee angle of the two lower limbs to raise the center of mass, the legged robot can return to a standing position after completing a low-center-of-mass leg sweep, thereby improving the transition between the leg sweep and the subsequent stable posture.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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 computer-readable 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, including the hips; Two lower limbs and their corresponding extremities 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, the at least one storage medium being encoded with instructions that, when executed by the at least one processor, cause the legged robot to: The legged robot is controlled to rotate in a first direction based on a preset leg-sweeping posture, wherein the first direction is either clockwise or counterclockwise. The preset leg-sweeping posture includes: a first distance between the hip and the contact surface of 1mm to 200mm, wherein the contact surface is a bearing surface that provides support for the legged robot; and a plane passing through the thigh, knee joint, and calf of the first lower limb is used as a reference plane, wherein the angle between the reference plane and the contact surface is less than or equal to 60°, and the knee joint angle of the first lower limb is... The angle is 20° to 90°, the lower limb end of the first lower limb is in a foot-side support state, the second distance between the knee joint of the first lower limb and the contact surface is 1mm to 400mm; the ratio of the minimum distance between the knee joint of the first lower limb and the knee joint of the second lower limb to the thigh length of the first lower limb is greater than or equal to 1, the included angle of the knee joint of the second lower limb is 110° to 180°, and the minimum distance between the lower limb end of the first lower limb and the hip is less than the minimum distance between the lower limb end of the second lower limb and the hip.

2. The legged robot according to claim 1, characterized in that, The first distance is less than the second distance, and the third distance between the knee joint of the second lower limb and the contact surface is less than the second distance between the knee joint of the first lower limb and the contact surface; The first distance is 5mm to 100mm, and the second distance is 10mm to 200mm; the knee joint angle of the first lower limb is 30° to 75°, and the knee joint angle of the second lower limb is 150° to 180°. During the process of controlling the legged robot to rotate in the first direction based on the preset leg sweeping posture, the angle of rotation of the legged robot in the first direction is greater than or equal to 100°.

3. The legged robot according to claim 1, characterized in that, The legged robot further includes two upper limbs connected to the torso and corresponding limb ends. The two upper limbs include a first upper limb and a second upper limb. The first upper limb includes a first connecting end and is connected to the torso through the first connecting end. The second upper limb includes a second connecting end and is connected to the torso through the second connecting end. The first upper limb and the first lower limb are located on the same side of the torso, and the second upper limb and the second lower limb are located on the same side of the torso. The preset leg sweeping posture also includes: The minimum distance between the knee joint of the first lower limb and the first connecting end is the fifth distance, and the minimum distance between the knee joint of the second lower limb and the second connecting end is the sixth distance. The ratio of the sixth distance to the fifth distance is 1.5 to 4.

0.

4. The legged robot according to claim 1, characterized in that, The legged robot also includes a first upper limb and a corresponding limb end connected to the torso, wherein the first upper limb and the first lower limb are located on the same side of the torso. The ratio of the minimum distance between the elbow joint of the first upper limb and the torso to the length of the upper arm of the first upper limb is 0.5 to 1.

5. The legged robot according to claim 1, characterized in that, The legged robot also includes a first upper limb and a corresponding limb end connected to the torso, wherein the first upper limb and the first lower limb are located on the same side of the torso; When the instruction is executed by the at least one processor, during the process of controlling the legged robot to rotate in the first direction based on the preset leg-sweeping posture, the legged robot: The distal end of the first upper limb is controlled to maintain contact with the contact surface, and the distal end of the second lower limb is controlled to maintain contact with the contact surface.

6. The legged robot according to claim 1, characterized in that, When the instruction is executed by the at least one processor, during the process of controlling the legged robot to rotate in the first direction based on the preset leg-sweeping posture, the legged robot: The legged robot is controlled to rotate in the first direction to a first threshold angle. During the rotation to the first threshold angle, the lower limb end of the first lower limb is controlled to maintain the foot side support state. During the rotation, the actual force point between the lower limb end of the first lower limb and the contact surface is controlled to move dynamically along the side contour of the lower limb end of the first lower limb. After the legged robot rotates beyond the first threshold angle, the contact area between the lower limb tip and the contact surface is switched from the side area of ​​the foot to the foot area.

7. The legged robot according to claim 1, characterized in that, When the instruction is executed by the at least one processor, during the process of controlling the legged robot to rotate in the first direction based on the preset leg-sweeping posture, the legged robot: In response to the command to stop sweeping the leg, the contact area between the lower limb end and the contact surface of the first lower limb is switched from the side area of ​​the foot to the foot area.

8. The legged robot according to any one of claims 1-7, characterized in that, The foot side of the lower limb of the first lower limb is made of metal.

9. The legged robot according to any one of claims 1-7, characterized in that, The legged robot also includes a second upper limb and a corresponding limb end connected to the torso, wherein the second upper limb and the first lower limb are located on different sides of the torso; When the instruction is executed by the at least one processor, before entering the preset leg-sweeping posture, it also causes the legged robot to: The torso is controlled to rotate in a second direction opposite to the first direction, and the elbow joint of the second upper limb is controlled to gradually move away from the torso; the first lower limb and / or the second lower limb are controlled to move away from each other in a direction to increase the distance between the lower limb ends of the first lower limb and the lower limb ends of the second lower limb; the knee joint angle between the first lower limb and the second lower limb is reduced, so that the center of gravity of the legged robot decreases.

10. The legged robot according to any one of claims 1-7, characterized in that, When the instruction is executed by the at least one processor, after controlling the legged robot to rotate in the first direction based on the preset leg-sweeping posture, the legged robot also causes: Control the lower limb ends of the first lower limb and the second lower limb to return to the foot support state, and control the center of mass of the legged robot to fall within the support polygon formed by the lower limb ends of the two lower limbs on the contact surface; Increasing the knee joint angle between the first and second lower limbs raises the center of gravity of the legged robot.

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