Robot Dynamics Identification for Accurate Stopping Distance Estimation

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Solution Overview

Problem

Traditional robotic system identification methods are cumbersome, incomplete, and unsuitable for dynamic real-time applications, leading to overly conservative safety measures and reduced fluidity in human-robot collaboration due to inaccurate and incomplete data on stopping distances and times, especially in collaborative applications where robots are lighter and more compliant.

Innovation Solution

An automated system for robotic system identification that estimates dynamic parameters based on motion and force data during known excitation trajectories, using a processor and memory with a database of robot models, a selection module, an excitation-trajectory module, a monitoring module, and a parameter solver to generate accurate stopping distance curves for specific applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional robotic system identification methods are used, then safety measures are implemented, but the methods are cumbersome and lead to overly conservative safety measures that reduce fluidity in human-robot collaboration

Engineering Contradiction:

ImprovesafetyVSAvoidfluidity in human-robot collaboration

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the parameters of system identification by using automated excitation trajectories and real-time data collection instead of traditional manual methods. This allows for more accurate dynamic parameter estimation (mass, inertia, friction) that reflects actual robot behavior, enabling less conservative safety zones and improved fluidity in collaborative spaces while maintaining reliability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The robot performs self-identification of its dynamic parameters by executing predefined excitation trajectories and collecting its own motion data. This automated self-characterization eliminates the need for cumbersome external testing and provides accurate, application-specific safety parameters that improve both reliability and operational fluidity

Inventive Principle:

Principle #25Self-service

2Reliability

If traditional system identification methods are used, then robot dynamics are characterized, but the data is inaccurate and incomplete leading to reduced productivity in dynamic applications

Engineering Contradiction:

Improveaccuracy of dynamic parametersVSAvoiddynamic performance

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent performs preliminary system identification by characterizing robot dynamic parameters (mass, inertia, friction) before actual production tasks. By pre-collecting accurate dynamic data through automated excitation trajectories, the system enables optimized control parameters and safety zones that maximize dynamic performance and productivity during subsequent operations

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces traditional mechanical testing methods with automated computational system identification. By using software-based excitation trajectories and data analysis instead of manual mechanical testing, the system achieves more accurate and complete dynamic parameter characterization, enabling better optimization of robot performance for high-speed dynamic applications

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Weight of moving object

If lightweight robot structures are used to reduce weight, then cost and safety improve, but the robot becomes more compliant with enhanced elastic effects making trajectory control more difficult

Engineering Contradiction:

Improverobot weightVSAvoidtrajectory control precision

Core Design Contradiction:

Weight of moving objectVSManufacturing precision

Solution Approach 1:

The patent implements feedback by using the identified dynamic parameters (including elastic effects) to create accurate equations of motion that account for compliance. The system continuously uses real-time data from excitation trajectories to refine the dynamic model, enabling controllers to compensate for elastic deformations and maintain precise trajectory control in lightweight robots

Inventive Principle:

Principle #23Feedback

4Speed

If sophisticated control systems are added to improve dynamic response, then speed and precision improve, but device complexity increases

Engineering Contradiction:

Improvedynamic response speedVSAvoidcontrol system complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The patent performs preliminary identification of dynamic parameters (mass, inertia, friction, elastic effects) to create accurate equations of motion before implementing control. This pre-characterization allows the use of optimized control algorithms that achieve high dynamic response with minimal complexity, as the controller works with pre-computed accurate models rather than requiring complex real-time adaptation

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11254004B2System identification of industrial robot dynamics for safety-critical applications

Publication Date: 2022.02.22 SYMBOTIC LLC

AI summary

Embodiments of the present invention provide automated robotic system identification and stopping time and distance estimation, significantly improving on existing ad-hoc methods of robotic system identification. Systems and methods in accordance herewith can be used by end users, system integrators, and the robot manufacturers to estimate the dynamic parameters of a robot on an application-by-application basis.