Method for performing zero moment point (ZMP) calibration autonomously by robot

Abstract

The invention provides a method for performing zero moment point (ZMP) calibration autonomously by a robot. The robot has at least two legs and feet, wherein the at least two legs can drive the robot to walk; the feet are connected with the legs through ankle joints respectively; and the feet are provided with force sensors. The method comprises the following steps of: calculating the projection of a barycenter of the robot on the ground according to each part and the position thereof of the robot, wherein the robot is supported by a single foot to maintain a certain stable fixed posture and the part above the ankle joint of the supporting foot of the robot is seen as a mass point; adjusting the ankle joint of the supporting foot of the robot so as to make the projection of the barycenter spread over the surface of the supporting foot; and obtaining a table by sampling, wherein in the table, a true ZMP corresponds to the ZMP measured by the force sensors. The robot can perform the ZMP calibration according to the projection of the barycenter of the robot and the movement of the ankle joints, so the method has the advantages of no need of human intervention, high efficiency, a large number of sampling points, high precision and low requirement on a mounting environment.

Description

technical field [0001] The invention relates to a method for calibrating the ZMP of a robot, in particular to a method for calibrating the ZMP of a humanoid robot independently. Background technique [0002] Humanoid robots (hereinafter referred to as robots) move by walking on two legs, just like people. Its legs are similar to human beings, and it has better maneuverability than traditional wheeled and tracked robots, especially on uneven ground, stairs, and occasions where there are only discrete and discontinuous contact points with the ground. Superiority. However, biped robots are inherently unstable and prone to falls. [0003] In order to make the robot walk, it is necessary to control the robot in real time according to the current environmental information and the current state of the robot to overcome the changes and uncertainties of the environment, so that the robot can walk stably in the actual environment. [0004] When controlling a humanoid robot to walk ...

AI Technical Summary

Problems solved by technology

[0006] Due to the influence of the measurement error of the force sensor, the installation environment, accuracy and error, etc.; or some parts of the foot need to be corrected during calibration, while some parts do not need to be corrected, if the entire foot is corrected or not corrected , resulting in a certain error between the ZMP measured by the sensor calibrated by these points and the real ZMP

In addition, calibration personnel are generally required to perform manual calibration multiple times. It is difficult to meet the requirement of being perpendicular to the foot surface by artificial force direction, and the number of calibrated points is limited, and it is difficult to cover the entire foot surface. It is very time-consuming and the degree of automation is not high.

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