3D Collision Force Evaluation for Safe Human-Robot Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for evaluating collisions between robots and living beings, such as humans, are inefficient due to high computational requirements, making it difficult to rapidly assess collision risks and adjust robot speeds to prevent injuries, especially in collaborative robotics where various contact situations arise frequently.
Innovation Solution
A method using geometric polygon mesh models and stress-deformation characteristic curves to simulate collisions in a virtual space, allowing for rapid calculation of contact forces and determination of safe robot speeds by shifting models in discrete steps and generating impression images to evaluate deformation and stress, thereby reducing computational effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If finite element methods (FEM) are used to evaluate collisions and determine force-deformation characteristic curves, then measurement precision and reliability are improved, but computational effort and time consumption increase significantly
Solution Approach 1:
The patent segments the continuous FEM model into discrete polygon mesh models with predefined stress-deformation characteristic curves for different body sites. This segmentation allows pre-calculated characteristic curves to be stored and rapidly applied during collision evaluation, eliminating the need for real-time FEM calculations while maintaining accuracy.
Solution Approach 2:
The patent performs preliminary calculations of force-deformation characteristic curves for various body sites and collision scenarios before actual robot operation. These pre-calculated curves are stored in a database, enabling rapid collision risk assessment during runtime without requiring complex real-time computations.
2Reliability
If comprehensive collision evaluation for all possible contact situations is performed, then safety and reliability are improved, but device complexity and computational requirements increase
Solution Approach 1:
The patent applies local quality by creating specific polygon mesh models and stress-deformation characteristic curves for different body sites (head, torso, limbs, etc.). Each site has its own tailored model and characteristic curve, allowing accurate local collision assessment without requiring a single overly complex universal model.
Solution Approach 2:
The patent creates a universal evaluation framework that can handle various collision scenarios (different objects, speeds, angles, and body sites) using a standardized approach with polygon mesh models and force-deformation curves. This universal system replaces multiple specialized evaluation methods with one multi-functional platform.
3Productivity
If real-time collision evaluation and robot speed adjustment are implemented, then productivity and operational efficiency are improved, but computational speed and processing power requirements increase
Solution Approach 1:
The patent uses simplified polygon mesh models as copies or approximations of complex FEM models. These mesh models with pre-stored characteristic curves serve as lightweight replicas that can be rapidly processed in real-time, replacing computationally intensive original FEM models while preserving essential collision evaluation capabilities.
Data Source
AI summary
The invention relates to evaluating a predetermined collision between a predetermined site (2) on the body of a living being and a predetermined object (1), comprising the steps of a) providing a 3D model of the predetermined object (1) on an arithmetic logic unit; b) providing a polygon mesh model of the predetermined site (2) on the body on an arithmetic logic unit, wherein each field Fij of the mesh of the polygon mesh model is square, and a stress-deformation characteristic curve (s) is predetermined for each field Fij of the mesh; c) aligning the provided 3D model and the provided polygon mesh model in a virtual space by means of the arithmetic logic unit, wherein the arrangement of the two models relative to one another corresponds to the relative arrangement of the object and the site on the body during the predetermined collision; d) gradually shifting the 3D model and the polygon mesh model into one another in a collision direction (K) determined by the predetermined collision, in the virtual space, by means of the arithmetic logic unit, wherein an impression image (AB) having impression pixels Pij is generated for each step k of the gradual shifting process and a respective pixel value Pw of the impression pixels Pij represents an impression depth of the 3D model in a field Fij of the mesh of the polygon mesh model that is assigned to the respective impression pixel Pij; e) determining the respective stress values for the impression pixels Pij for the or at least one of the impression images (AB, AB′, AB″) according to the stress-deformation characteristic curve (s) assigned to the corresponding field Fij and the respective pixel value Pw; f) calculating a force F acting on the predetermined site (2) on the body by adding up the products of the stress values determined for the impression pixels Pij with the surface areas Aij of the assigned fields Fij of the mesh, for the step k corresponding to the at least one impression image (AB, AB′, AB″); in order to rapidly and accurately evaluate any predeterminable collisions between sites on the bodies of living beings and any objects, in particular with regard to a risk of injury to an operator, for example.