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US 12,746,676 B2Granted
Joint diagnosis method and apparatus, and robot
AssigneeElite Intelligent Robot Co., Ltd.
InventorsKe Wang, Kai Sun, Yunan Cao
Life of this patent
Estimating the term…
Abstract
A joint diagnosis method, including steps: collecting data of a current motion trajectory of a robot, solving for a frictional force of a joint, performing temperature compensation on a friction model based on a feedback temperature of the joint, and solving for an output torque of a connecting rod of the joint, to acquire a dynamics model error; performing detection and analysis on the dynamics model error, to acquire modal analysis and joint wear degree results; and determining, based on the modal analysis and joint wear degree results, whether the joint is in an abnormal wear state, and if the joint is in the abnormal wear state, triggering a joint abnormity alarm, otherwise, performing calibration on the friction model.
Claims10
A joint diagnosis method, characterized by comprising steps:
- collecting data of a current motion trajectory of a robot, solving for a frictional force of a joint, performing temperature compensation on a friction model based on a feedback temperature of the joint, and solving for an output torque of a linkage of the joint, to acquire a dynamics model error;
- performing detection and analysis on the dynamics model error, to acquire modal analysis and joint wear degree results;
- determining, based on the modal analysis and joint wear degree results, whether the joint is in an abnormal wear state, and if the joint is in the abnormal wear state, triggering a joint abnormity alarm, otherwise, performing calibration on the friction model;
- in a process of the detection and analysis of the dynamics model error, performing an FFT transform on the dynamics model error firstly, acquiring a signal amplitude of a modal that is greater than a frequency f in the dynamics model error based on the FFT transform results, and determining whether the signal amplitude exceeds a set first threshold t1;
- if the signal amplitude exceeds the set first threshold t1, the joint is in the abnormal wear state, triggering the joint abnormity alarm, and prompting for necessity for joint replacement;
- and if the signal amplitude does not exceed the set first threshold t1, further determining whether the dynamics model error exceeds a second threshold t2;
- if the dynamics model error does not exceed the second threshold t2, it is indicated that a state of the current joint is normal and the dynamics model is acceptable, the joint is not in the abnormal wear state, and there is no necessity for calibration on the friction model, also executing the collecting step;
- and if the dynamics model error exceeds the second threshold t2, further determining whether the dynamics model error exceeds k times the calculated value of the friction model stored in the current joint;
- if the dynamics model error exceeds k times for the friction model stored in the current joint, it is indicated that the current joint is in the abnormal wear state, triggering the joint abnormity alarm, and prompting for necessity for joint replacement;
- and if the dynamics model error does not exceed k times for the friction model stored in the current joint, it is indicated that the joint is in a normal wear state, and an operation of performing calibration on the friction model is required;
- the performing calibration on the friction model comprising at least steps:
- executing a calibration trajectory by the joint of the robot and collecting the motion feedback data of the robot in real time, filtering the motion feedback data, extracting friction torques of joints at different velocity segments, solving for online calibrated parameters of the friction model, and storing the parameters of the friction model into the joint of the robot.
9 more elements
A joint diagnosis apparatus, characterized by comprising:
- a robot dynamics model calculation device configured for realizing functions of acquiring feedback data, calculating for linkage dynamics for the robot, calculating a frictional force, performing temperature compensation, and calculating a model error;
- a joint abnormity detection device configured for detecting and determining whether a joint is in an abnormal wear state, and if the joint is in the abnormal wear state, triggering a joint abnormity alarm, otherwise, performing calibration on a friction model;
- a friction model calibration device configured for executing a calibration trajectory, filtering motion feedback data, and solving for calibrated parameters of the friction model based on the motion data of the robot;
- a joint abnormity alarm device configured for conveying a warning message to users about replacing the joint;
- in a process of the detection and analysis of the dynamics model error, performing an FFT transform on the dynamics model error firstly, acquiring a signal amplitude of a modal that is greater than a frequency f in the dynamics model error based on the FFT transform results, and determining whether the signal amplitude exceeds a set first threshold t1;
- if the signal amplitude exceeds the set first threshold t1, the joint is in the abnormal wear state, triggering the joint abnormity alarm, and prompting for necessity for joint replacement;
- and if the signal amplitude does not exceed the set first threshold t1, further determining whether the dynamics model error exceeds a second threshold t2;
- if the dynamics model error does not exceed the second threshold t2, it is indicated that a state of the current joint is normal and the dynamics model is acceptable, the joint is not in the abnormal wear state, and there is no necessity for calibration on the friction model, also executing the collecting step;
- and if the dynamics model error exceeds the second threshold t2, further determining whether the dynamics model error exceeds k times the calculated value of the friction model stored in the current joint;
- if the dynamics model error exceeds k times for the friction model stored in the current joint, it is indicated that the current joint is in the abnormal wear state, triggering the joint abnormity alarm, and prompting for necessity for joint replacement;
- and if the dynamics model error does not exceed k times for the friction model stored in the current joint, it is indicated that the joint is in a normal wear state, and an operation of performing calibration on the friction model is required;
- and
- the performing calibration on the friction model comprising at least steps:
- executing a calibration trajectory by the joint of the robot and collecting the motion feedback data of the robot in real time, filtering the motion feedback data, extracting friction torques of joints at different velocity segments, solving for online calibrated parameters of the friction model, and storing the parameters of the friction model into the joint of the robot.
11 more elements
Dependencies are inferred from the claim text.