Biped robot and its moving method and apparatus

Patent metadata

Field	Value
Publication number	US-11550335-B2
Application number	US-201816753408-A
Country	US
Kind code	B2
Filing date	Nov 28, 2018
Priority date	Nov 28, 2018
Publication date	Jan 10, 2023
Grant date	Jan 10, 2023

Abstract

The present disclosure discloses a biped robot and its moving method and apparatus. The method includes: calculating a motion state of each servo of legs of a biped robot according to an actual trajectory of the biped robot, and controlling the servo to rotate to the corresponding motion state. The scheme enables the biped robot to achieve flexible controls to the biped robot according to the received real-time external feedbacks.

First claim

What is claimed is:

1. A computer-implemented moving method for a biped robot, comprising executing on a processor steps of:
obtaining an actual movement trajectory X d_new of the biped robot;
calculating target angles θ lb and θ rb of servos of two legs of the biped robot, respectively, according to the actual movement trajectory X d_new , wherein each leg of the biped robot is composed of a plurality of servos connected sequentially in series; and
controlling each servo of the two legs of the biped robot to rotate to angles corresponding to the target angles θ lb and θ rb , respectively;
wherein a sole of each of the two legs of the biped robot is equipped with a six-dimensional sensor for detecting a six-dimensional force on the sole, and the step of obtaining the actual movement trajectory X d_new of the biped robot comprises:
collecting force data of the six-dimensional sensor on the sole of each of the two legs of the biped robot, and angle data of the servos of each leg of the biped robot;
calculating force information upon a body of the biped robot according to the force data and the angle data; and
calculating the actual movement trajectory of the biped robot based on the force information and attribute information of the biped robot.

2. The method of claim 1 , wherein the step of calculating the force information upon the body of the biped robot according to the force data and the angle data comprises:
generating matrices F l and F r based on the force data of each sole, and generating matrices θ la and θ ra based on the angular data of each leg;
calculating a Jacobian matrix of the two legs based on the matrices θ la and θ ra , respectively, to obtain matrices J l and J r ; and
calculating the force information upon the body of the biped robot through a formula F b =J l T F l +J r T F r , where F b represents the force information upon the body of the biped robot.

3. The method of claim 1 , wherein the step of calculating the actual movement trajectory of the biped robot based on the force information and the attribute information of the biped robot comprises:
calculating an acceleration of the biped robot based on the force information and a body mass of the biped robot;
calculating a change trajectory of a centroid according to the acceleration of the biped robot and a movement speed of the biped robot; and
obtaining the actual trajectory of the biped robot by adding the change trajectory of the centroid and a planned movement trajectory of the biped robot.

4. The method of claim 1 , wherein the step of calculating the target angles θ lb and θ rb of the servos of two legs of the biped robot, respectively, according to the actual movement trajectory X d_new comprises:
calculating the target angles θ lb and θ rb inputting the actual movement trajectory to a body centroid position in inverse kinematics.

5. The method of claim 1 , wherein each leg of the biped body robot comprises 6 servos.

6. The method of claim 1 , wherein the step of calculating the actual movement trajectory of the biped robot based on the force information and attribute information of the biped robot comprises:
retrieving the attribute information of the biped robot from a storage of the biped robot, wherein the attribute information of the biped robot comprises: a body mass, a damping coefficient, and a stiffness coefficient;
calculating a change trajectory of the centroid of the biped robot according to the force information, the body mass, the damping coefficient, and the stiffness coefficient, using a impedance algorithm and a inverse Laplace transform; and
obtaining the actual trajectory of the biped robot by adding the change trajectory of the centroid and a planned movement trajectory of the biped robot.

7. A moving apparatus for a biped robot, comprising:
an obtaining module configured to obtain an actual movement trajectory X d_new of the biped robot;
a calculation module configured to calculate target angles θ lb and θ rb of servos of two legs of the biped robot, respectively, according to the actual movement trajectory X d_new , wherein each leg of the biped robot is composed of a plurality of servos connected sequentially in series; and
a control module configured to control each servo of the two legs of the biped robot to rotate to angles corresponding to the target angles θ lb and θ rb , respectively;
wherein a sole of each of the two legs of the biped robot is equipped with a six-dimensional sensor for detecting a six-dimensional force on the sole, and the obtaining module is further configured to:
collect force data of the six-dimensional sensor on the sole of each of the two legs of the biped robot, and angle data of the servos of each leg of the biped robot;
calculate force information upon a body of the biped robot according to the force data and the angle data; and
calculate the actual movement trajectory of the biped robot based on the force information and attribute information of the biped robot.

8. The moving apparatus of claim 7 , wherein the obtaining module is further configured to:
generate matrices F l and F r based on the force data of each sole, and generating matrices θ la and θ ra based on the angular data of each leg;
calculate a Jacobian matrix of the two legs based on the matrices θ la and θ ra , respectively, to obtain matrices J l and J r ; and
calculate the force information upon the body of the biped robot through a formula F b =J l T F l +J r T F r , where F b represents the force information upon the body of the biped robot.

9. The moving apparatus of claim 7 , wherein the obtaining module is further configured to:
calculate an acceleration of the biped robot based on the force information and a body mass of the biped robot;
calculate a change trajectory of a centroid according to the acceleration of the biped robot and a movement speed of the biped robot; and
obtain the actual trajectory of the biped robot by adding the change trajectory of the centroid and a planned movement trajectory of the biped robot.

10. The moving apparatus of claim 7 , wherein the calculation module is further configured to:
calculate the target angles θ lb and θ rb by inputting the actual movement trajectory to a body centroid position in inverse kinematics.

11. The moving apparatus of claim 7 , wherein each leg of the biped body robot comprises 6 servos.

12. The moving apparatus of claim 7 , wherein the obtaining module is further configured to:
retrieve the attribute information of the biped robot from a storage of the biped robot, wherein the attribute information of the biped robot comprises: a body mass, a damping coefficient, and a stiffness coefficient;
calculate a change trajectory of the centroid of the biped robot according to the force information, the body mass, the damping coefficient, and the stiffness coefficient, using a impedance algorithm and a inverse Laplace transform; and
obtain the actual trajectory of the biped robot by adding the change trajectory of the centroid and a planned movement trajectory of the biped robot.

13. A biped robot comprising:
a memory; and
a processor;
wherein the memory stores a computer program executable on the processor, and the computer program comprises:
instructions for obtaining an actual movement trajectory X d_new of the biped robot;
instructions for calculating target angles θ lb and θ rb of servos of two legs of the biped robot, respectively, according to the actual movement trajectory X d_new , wherein each leg of the biped robot is composed of a plurality of servos connected sequentially in series; and
in

Assignees

• Ubtech Robotics Corp
• Ubtech Robotics Corp Ltd

Inventors

• Xiong Youjun
• Chen Chunyu
• Liu Yizhang
• Ge Ligang
• Xie Zheng
• Pang Jianxin

Classifications

• B25J9/16

  Program controls (total factory control, i.e. centrally controlling a plurality of machines, G05B19/418) · CPC title

• B62D57/032

  with alternately or sequentially lifted supporting base and legs; with alternately or sequentially lifted feet or skid (B62D57/024 takes precedence) · CPC title

• G05D2201/0217

  Physics · mapped topic

• G05D1/027 Primary

  comprising intertial navigation means, e.g. azimuth detector (inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165) · CPC title

• G05D1/0212 Primary

  with means for defining a desired trajectory (involving a plurality of land vehicles G05D1/0287) · CPC title