Patents by Inventor Ligang Ge

Ligang Ge has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11926056
    Abstract: A gait planning method and a robot using the same as well as a computer readable storage medium are provided. The method includes: determining a reference leg length l0 and a leg length variation range A of a robot; performing a trajectory planning on a length of at least one of the legs of the robot using; an equation including the reference leg length, the leg length variation range, and a preset recurrent excitation function of a time variable t. In this manner, the trajectory planning for the leg length of the robot during motion is performed according to the characteristics of motion scene such as robot jumping or running so that the change of the leg length of the robot is adapted to the motion process, which greatly improves the stability of the robot in the motion scene such as jumping or running.
    Type: Grant
    Filed: February 23, 2022
    Date of Patent: March 12, 2024
    Assignee: UBTECH ROBOTICS CORP LTD
    Inventors: Jie Bai, Yizhang Liu, Ligang Ge, Chunyu Chen, Qiuyue Luo, Youjun Xiong
  • Patent number: 11926052
    Abstract: A robot control method includes: acquiring distances between a center of mass (COM) of the biped robot and each of preset key points of feet of the biped robot, and acquiring an initial position of the COM of the biped robot; calculating a position offset of the COM based on the distances; adjusting the initial position of the COM based on the position offset of the COM to obtain a desired position of the COM of the biped robot; and determining desired walking parameters of the biped robot based on the desired position of the COM by using a preset inverse kinematics algorithm, wherein the desired walking parameters are configured to control the biped robot to walk.
    Type: Grant
    Filed: December 23, 2020
    Date of Patent: March 12, 2024
    Assignee: UBTECH ROBOTICS CORP LTD
    Inventors: Chunyu Chen, Yizhang Liu, Ligang Ge, Zheng Xie, Youjun Xiong, Jianxin Pang
  • Patent number: 11904472
    Abstract: A humanoid robot control method, a mobile machine using the same, and a computer readable storage medium are provided. The method includes: mapping posture information of leg joints of a human body to leg joint servos of a humanoid robot to obtain an expected rotation angle and an expected rotation angular velocity of non-target optimized joint servos of the leg joint servos and an expected rotation angle and an expected rotation angular velocity of target optimized joint servos of the leg joint servos; obtaining an optimization objective function corresponding to the target optimized joint servos of the leg joint servos; optimizing the expected rotation angle and the expected rotation angular velocity of the target optimized joint servos to obtain a corrected expected rotation angle and a corrected expected rotation angular velocity of the target optimized joint servos; and controlling each of the leg joint servos of the humanoid robot.
    Type: Grant
    Filed: October 19, 2021
    Date of Patent: February 20, 2024
    Assignee: UBTECH ROBOTICS CORP LTD
    Inventors: Jie Bai, Ligang Ge, Yizhang Liu, Youjun Xiong
  • Patent number: 11878426
    Abstract: A biped robot gait control method as well as a robot and a computer readable storage medium are provided. During the movement, the system obtains a current supporting pose of a current supporting leg of the biped robot, and calculates a relative pose between the supporting legs based on the current supporting pose and a preset ideal supporting pose of a next step. The system further calculates modified gait parameters of the next step based on the relative pose between the two supporting legs and a joint distance between left and right ankle joints in an initial state of the biped robot when standing. Finally, the system controls the next supporting leg to move according to the modified gait parameters.
    Type: Grant
    Filed: May 6, 2021
    Date of Patent: January 23, 2024
    Assignee: UBTECH ROBOTICS CORP LTD
    Inventors: Xingxing Ma, Chunyu Chen, Ligang Ge, Hongge Wang, Mingqiang Huang, Jiangchen Zhou, Yizhang Liu, Zheng Xie, Youjun Xiong
  • Publication number: 20240017404
    Abstract: A robot step length control method, a robot controller, and a computer-readable storage medium are provided. The method includes: if it detects that a humanoid robot is not in a balanced state at a current time, it correspondingly obtains a torso deflection posture parameter, a lower limb parameter and a leg swing frequency of the legs of the humanoid robot at the current time; and it calculates, using a swinging leg capture point algorithm, a calculated step length for maintaining a stable state of the humanoid robot that meets a posture balance requirement of the robot at the current time based on the torso deflection posture parameter, the lower limb parameter, and the leg swing frequency, so that the humanoid robot can be restored to the balanced state after moving with the calculated step length, thereby improving the anti-interference ability of the robot.
    Type: Application
    Filed: September 22, 2023
    Publication date: January 18, 2024
    Inventors: Chunyu Chen, Yizhang Liu, Ligang Ge, Zheng Xie, Youjun Xiong
  • Publication number: 20240009842
    Abstract: A method for controlling a robot based on a trajectory of a center of mass (COM) of the robot includes: calculate a desired periodic trajectory of the robot in a single gait cycle based on a dynamic equation constructed according to a simplified model of the robot; correct the desired periodic trajectory according to a fed-back state of the COM of the robot; generate a desired trajectory of the COM of the robot using the corrected desired periodic trajectory; and control motion of the robot according to the desired trajectory of the COM of the robot.
    Type: Application
    Filed: July 6, 2023
    Publication date: January 11, 2024
    Inventors: QIUYUE LUO, Ligang Ge, Chunyu Chen, Xuan Luo
  • Publication number: 20230415333
    Abstract: A center of mass (COM) planning method includes: obtaining a planning position of the COM and a planning speed of the COM of a robot, and calculating a planning capture point of the robot according to the planning position of the COM and the planning speed of the COM; obtaining a measured position of the COM and a measured speed of the COM, and calculating a measured capture point of the robot according to the measured position the measured speed; calculating a desired zero moment point (ZMP) of the robot based on the planning capture point and the measured capture point; obtaining a measured ZMP of the robot, and calculating an amount of change in a position of the COM according to the desired ZMP and the measured ZMP; and correcting the planning position of the COM according to the amount of change in the position of the COM.
    Type: Application
    Filed: September 19, 2023
    Publication date: December 28, 2023
    Inventors: Ligang Ge, Yizhang Liu, Chunyu Chen, Zheng Xie, Youjun Xiong
  • Publication number: 20230359207
    Abstract: A trajectory planning method, a computer-readable storage medium, and a robot are provided. The method includes: constructing a phase variable of a trajectory planning of a robot, where the phase variable is a function of two position components of a torso of the robot on a horizontal plane; and performing, using the phase variable replacing a time variable, the trajectory planning on a swinging leg of the robot in each preset coordinate axis direction. In this manner, the robot can no longer continue to follow the established trajectory after being disturbed by the environment, but make state adjustments according to the disturbance received to offset the impact of the disturbance, thereby maintaining walking stability and avoiding the problem of early or late landing of the swinging leg.
    Type: Application
    Filed: July 16, 2023
    Publication date: November 9, 2023
    Inventors: QIUYUE LUO, Ligang Ge, Yizhang Liu, Jie Bai, Youjun Xiong
  • Publication number: 20230278212
    Abstract: A gait planning method for a robot includes: constructing a first phase variable of a gait planning of the robot, wherein the first phase variable is a function of two position components of a torso of the robot on a horizontal plane; constructing a second phase variable based on the first phase variable, wherein the second phase variable is a function of the first phase variable, and a slope of the second phase variable is smaller than a slope of the first phase variable when a foot of a swing leg of the robot starts to touch a support surface; and performing the gait planning on the foot of the swing leg using the second phase variable to obtain a planned trajectory of the foot of the swing leg.
    Type: Application
    Filed: December 29, 2022
    Publication date: September 7, 2023
    Inventors: QIUYUE LUO, Yizhang Liu, Ligang Ge, Chunyu Chen, Jiangchen Zhou, Meng Yen
  • Publication number: 20230271656
    Abstract: A robot state estimation method, a computer-readable storage medium, and a legged robot are provided. The method includes: obtaining force information of a left leg of a robot and a right leg of the robot; calculating a ZMP of the robot in a world coordinate system based on the force information of the left leg and the force information of the right leg; and calculating a position of a center of mass (CoM) of the robot based on a preset linear inverted pendulum model. In this manner, a brand-new linear inverted pendulum model is constructed in advance, which uses the ZMP of the robot as a supporting point of the model, thereby fully considering the influence of the change of the position of the ZMP of the robot on the position of the CoM.
    Type: Application
    Filed: May 5, 2023
    Publication date: August 31, 2023
    Inventors: Ligang Ge, Yizhang Liu, Chunyu Chen, Zheng Xie, Youjun Xiong
  • Publication number: 20230234655
    Abstract: A robot step control method, a robot control apparatus, and a storage medium are provided. The method includes: determining an expected support force of two legs of a biped robot according to zero-moment point planning data and actual position data of the two legs at a current moment, and determining a current desired joint posture angle of ankle joints of the two legs and a desired joint position matching an actual leg support state using a compliance control algorithm based on an expected support force of the two legs, and centroid movement planning data, centroid actual movement data, step planning data and actual force data of the two legs at the current moment. In such manner, all-direction compliant controls can be performed on a desired leg pose condition according to the actual motion status of the biped robot, thereby improving the walking stability and terrain adaptability of the biped robot.
    Type: Application
    Filed: December 29, 2022
    Publication date: July 27, 2023
    Inventors: Ligang Ge, Yizhang Liu, Qiuyue Luo, Chunyu Chen, Xuan Luo, Jiangchen Zhou
  • Patent number: 11693430
    Abstract: A computer-implemented gait planning method includes: determining a pitch angle between a foot of the robot and a support surface where the robot stands; determining a support point on a sole of the foot according to the pitch angle; calculating an ankle-foot position vector according to the support point, wherein the ankle-foot position vector is a position vector from an ankle of the robot to a support point on a sole of the foot; calculating a magnitude of change of an ankle position according to the pitch angle and the ankle-foot position vector; and obtaining a compensated ankle position by compensating the ankle position according to the magnitude of change of the ankle position.
    Type: Grant
    Filed: December 8, 2020
    Date of Patent: July 4, 2023
    Assignee: UBTECH ROBOTICS CORP LTD
    Inventors: Jie Bai, Ligang Ge, Yizhang Liu, Hongge Wang, Jianxin Pang, Youjun Xiong
  • Patent number: 11691284
    Abstract: A robot control method includes: obtaining force information associated with a left foot and a right foot of the robot; calculating a zero moment point of a COM of a body of the robot based on the force information; updating a motion trajectory of the robot according to the zero moment point of the COM of the body to obtain an updated position of the COM of the body; performing inverse kinematics analysis on the updated position of the COM of the body to obtain joint angles of a left leg and a right leg of the robot; and controlling the robot to move according to the joint angles.
    Type: Grant
    Filed: December 13, 2020
    Date of Patent: July 4, 2023
    Assignee: UBTECH ROBOTICS CORP LTD
    Inventors: Chunyu Chen, Yizhang Liu, Ligang Ge, Zheng Xie, Hongge Wang, Youjun Xiong, Jianxin Pang
  • Publication number: 20230202027
    Abstract: A walking control method for a biped robot includes: detecting whether the biped robot is in an unbalanced state; in response to detection that the biped robot is in the unbalanced state, obtaining a predicted balance step length corresponding to the biped robot in the unbalanced state; performing a smooth transition processing on the predicted balance step length according to a current movement step length of the biped robot to obtain a desired balance step length corresponding to the predicted balance step length; determining a planned leg trajectory of the biped robot according to the desired balance step length; and controlling a current swing leg of the biped robot to move according to the planned leg trajectory.
    Type: Application
    Filed: December 28, 2022
    Publication date: June 29, 2023
    Inventors: CHUNYU CHEN, Jie Bai, Yizhang Liu, Ligang Ge, Zheng Xie, Youjun Xiong
  • Publication number: 20230191604
    Abstract: A robot stability control method includes: obtaining a desired zero moment point (ZMP) and a fed-back actual ZMP of a robot at a current moment; based on a ZMP tracking control model, the desired ZMP and the actual ZMP, calculating a desired value of a motion state of a center of mass of the robot at the current moment, wherein the desired value of the motion state of the center of mass comprises a correction amount of the position of the center of mass; based on a spring-mass-damping-acceleration model and the desired value of the motion state of the center of mass, calculating a lead control input amount for the correction amount of the position of the center of mass; and controlling motion of the robot according to the lead control input amount and a planned value of the position of the center of mass at the current moment.
    Type: Application
    Filed: November 29, 2022
    Publication date: June 22, 2023
    Inventors: Ligang Ge, Yizhang Liu, Chunyu Chen, Qiuyue Luo, Jiangchen Zhou, Meng Yan, Youjun Xiong
  • Publication number: 20230182297
    Abstract: A method of controlling a robot includes: obtaining an inertia matrix and a slack variable of the robot, and determining a momentum equation of the robot according to the inertia matrix and the slack variable; obtaining reference joint angles corresponding to a reference action of the robot; determining an optimization objective function of the momentum equation according to a first preset weight coefficient of the slack variable and a second preset weight coefficient of the reference joint angles; and determining joint angles of the robot according to the optimization objective function, and driving the robot to move according to the joint angles of the robot.
    Type: Application
    Filed: November 28, 2022
    Publication date: June 15, 2023
    Inventors: CHUNYU CHEN, Ligang Ge, Yizhang Liu, Jiangchen Zhou, Qiuyue Luo, Youjun Xiong
  • Publication number: 20230182307
    Abstract: A jumping motion control method for a biped robot includes: before feet of the biped robot leaves a support surface, estimating a motion trajectory of the biped robot that leaves the support surface according to a period of time when the biped robot stays or flips in the air; calculating a first motion angle of each joint of legs of the biped robot according to the motion trajectory and inverse kinematics; determining a constraint condition according to a motion type to which an action to be performed by the biped robot corresponds; optimizing the first motion angles according to the constraint condition to obtain a second motion angle of each joint of legs of the biped robot; and controlling a jumping motion of the biped robot according to the second motion angles.
    Type: Application
    Filed: October 31, 2022
    Publication date: June 15, 2023
    Inventors: CHUNYU CHEN, Ligang Ge, Yizhang Liu, Jiangchen Zhou, Qiuhue Luo, Youjun Xiong
  • Publication number: 20230133934
    Abstract: A method for controlling a legged robot includes: in response to detection of a collision event associated with a foot of a swing leg of the biped robot, terminating a trajectory component planning of the swing leg in a collision direction; calculating a position offset in the collision direction according to an external force that is received by the foot of the swing leg in the collision direction and obtained in real time, based on a foot dragging control mode, and determining a replanned trajectory component in the collision direction based on the position offset; and controlling the swing leg to move based on the replanned trajectory component in the collision direction and a desired trajectory component of the swing leg in a non-collision direction.
    Type: Application
    Filed: December 28, 2022
    Publication date: May 4, 2023
    Inventors: Chunyu Chen, Yizhang Liu, Ligang Ge, Jie Bai, Jiangchen Zhou, Qiuyue Luo, Youjun Xiong
  • Publication number: 20230101489
    Abstract: A joint acceleration planning method, a redundant robot using the same, and a computer readable storage medium are provided.
    Type: Application
    Filed: December 16, 2021
    Publication date: March 30, 2023
    Inventors: Yizhang Liu, Youjun Xiong, Xuan Luo, Xianwen Zeng, Ligang Ge, Chunyu Chen
  • Patent number: 11602848
    Abstract: A robot control method includes: obtaining force information associated with feet of the robot; calculating a zero moment point of a COM of a body of the robot based on the force information; updating a position trajectory of the robot according to the zero moment point of the COM of the body to obtain an updated position of the COM of the body; obtaining posture information of the robot; updating a posture trajectory of the robot according to the posture information to obtain an updated pose angle; performing inverse kinematics analysis on the updated position of the COM of the body and the updated pose angle to obtain joint angles of legs of the robot; and controlling the robot to move according to the joint angles.
    Type: Grant
    Filed: December 13, 2020
    Date of Patent: March 14, 2023
    Assignee: UBTECH ROBOTICS CORP LTD
    Inventors: Chunyu Chen, Yizhang Liu, Ligang Ge, Zheng Xie, Jianxin Pang, Youjun Xiong