Braking Range Envelope for Kinematic Systems

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Solution Overview

Problem

Current methods for controlling kinematics in robotics are inefficient in calculating the braking range during a braking process, often resulting in unnecessary braking due to conservative estimates, which can lead to false collision detections and increased computing effort.

Innovation Solution

A method that determines a virtual end position for a point coupled to a single axis based on its initial position, vectorial speed, and minimum deceleration, calculating a braking range as the envelope of the starting and end positions, and accounts for this range in controlling the kinematics, using vectorial speed and deceleration to ensure accurate stopping within the braking distance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conservative braking area is designed using a circle or sphere with radius equal to the sum of individual braking distances, then the safety is improved, but the computing effort increases and false braking occurs

Engineering Contradiction:
ImprovesafetyVSAvoidcomputing effort
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the braking distance calculation by determining individual braking distances for each axis separately based on their respective speeds and decelerations, then combining these segmented calculations to form the overall braking area. This avoids the need to calculate a single conservative spherical boundary while maintaining safety.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameters used for braking area calculation from a conservative spherical model (single radius based on sum of individual distances) to a more precise model that considers the actual kinematic state, speeds, and decelerations of individual axes. This parameter change enables accurate braking range determination with reduced computing effort.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the braking area is calculated conservatively using geometric bodies, then the safety is improved, but the reaction time increases due to computational expense

Engineering Contradiction:
ImprovesafetyVSAvoidreaction time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs preliminary calculations of individual axis braking distances and velocities before determining the overall braking area. By pre-calculating the braking distance for each axis based on current speed and deceleration characteristics, the system prepares the necessary data for rapid assembly of the total braking range, reducing reaction time while maintaining safety.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent transitions from using fixed geometric body parameters (sphere/circle with conservative radius) to dynamic parameters that reflect actual axis speeds and decelerations. This allows the braking area to be calculated based on real-time kinematic data, improving both accuracy and computational efficiency for faster reaction times.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the braking range is calculated with high accuracy considering individual axis parameters, then the false braking is reduced, but the computing effort increases

Engineering Contradiction:
Improvebraking range accuracyVSAvoidcomputing effort
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the complex braking range calculation into simpler individual axis calculations. Each axis contributes its own braking distance and directional information, which are then combined to form the overall braking area. This segmentation maintains high accuracy while reducing computational complexity compared to conservative spherical models.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses precise parameters (individual axis speeds, decelerations, and braking distances) to calculate the braking range accurately. By changing from conservative estimated parameters to actual measured parameters, the system achieves higher precision without excessive computing effort, as each parameter is derived from straightforward kinematic relationships.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3556521B1Brake path monitoring of a kinematic
Publication Date: 2023.05.24 B&R IND AUTOMATION GMBH
  • EP3556521B1 patent drawingFigure 1~4B
  • EP3556521B1 patent drawingFigure 2a~2h
  • EP3556521B1 patent drawingFigure 3

AI summary

In order to calculate a potentially swept braking range with increased accuracy and efficiency for a kinematic system (CGS) modeled in a kinematic coordinate system (CGS) using jointly connected individual axes (Q1,Q2,Q3), wherein at least one of the individual axes (Q1,Q2,Q3) is connected to an origin (CGS0) of the kinematic coordinate system (CGS) and at least one of the individual axes (Q1,Q2,Q3) moves relative to the origin (CGS0), the invention states that during the braking process, at least one virtual end position (p1,...,p7) of the point (P) coupled to an individual axis (Q1,Q2,Q3) is determined from an initial position (p0) of the point (P), a vector velocity (v1) of at least one individual axis (Q1,Q2,Q3), and a minimum deceleration (a1, a2, a3) of at least one individual axis (Q1,Q2,Q3). and the braking area of ​​point (P) by an envelope (E) of the initial position (p0) and the at least one virtual end position (p1,...,p7) is determined, whereby the extent of the envelope (E) is calculated from the initial position (p0) and the at least one virtual end position (p1,...,p7) and is taken into account in the control of the kinematics (1).