Robotic Collision Speed Limits Using Contact-Specific Impact Models
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the permissible maximum speed of robotic devices to prevent injuries are inefficient, as they require retrospective validation and often result in overly conservative speed limits due to the use of simplistic collision models, leading to long iteration loops and planning uncertainties.
Innovation Solution
A computer-implemented method that predefines the permissible maximum speed of a robotic device by considering specific contact points and spatial boundary conditions, using a combination of free-impact, clamping-impact, and quasi-static-clamping models to calculate safe speeds for both fast and slow collisions, allowing for real-time adjustments and location-dependent speed specifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If retrospective validation by physical measurements is used to determine permissible maximum speed, then safety compliance is achieved, but iteration loops are long and planning uncertainty is high
Solution Approach 1:
The patent applies preliminary action by calculating permissible maximum speeds using theoretical collision models before actual operation. The control unit pre-determines safe speed limits based on simulated collision scenarios, eliminating the need for lengthy retrospective physical validation and enabling immediate safe operation.
Solution Approach 2:
The patent replaces mechanical physical measurement validation with computational collision models. Instead of conducting actual physical tests to validate safety, the system uses mathematical models (spring-mass-damper systems) to simulate collisions and calculate safe speed limits, significantly reducing validation time.
2Productivity
If simplistic collision models are used to calculate permissible maximum speed, then calculation speed is fast, but the resulting speed limits are overly conservative and reduce productivity
Solution Approach 1:
The patent changes key parameters of the collision model, specifically using non-linear spring characteristics and realistic mass values instead of simplified linear models. This allows the system to maintain fast computational speed while achieving more accurate, less conservative speed limits that preserve productivity.
Solution Approach 2:
The patent introduces dynamic elements into the collision model by using non-linear spring characteristics that adapt to different collision conditions. The model dynamically adjusts its behavior based on the specific collision scenario, providing accurate speed limits without being overly conservative.
3Measurement precision
If a single collision model is used for all collision scenarios, then device complexity is low, but accuracy varies for different collision types (fast vs. slow collisions)
Solution Approach 1:
The patent applies local quality by using different collision models for different collision scenarios. Fast collisions use one optimized model while slow collisions use another, allowing each model to be specialized for its specific scenario and achieving high accuracy without unnecessary complexity across all scenarios.
Solution Approach 2:
The patent segments the collision assessment into different models based on collision type. By dividing the problem into fast collision scenarios and slow collision scenarios with dedicated models for each, the system achieves high accuracy for each segment while keeping individual model complexities manageable.
Data Source
AI summary
Predefining a permissible maximum speed for a robotic device may include predefining a contact point between a human operator and the robotic device for a collision between the human operator and the robotic device, a geometry of the robotic device at the contact point, and a spatial boundary condition of the collision. The method may also include determining whether the collision is a clamp-free collision or a clamped collision using a computing unit. The method may also include calculating, by the computing unit, the permissible maximum speed of the robotic device at the contact point with a free-impact model, and with a clamping-impact model or with a quasi-static-clamping model. The method may also include using the computing unit to output a signal dependent on the calculated permissible maximum speed for the robotic device to predefine the permissible maximum speed of the robotic device.