Motion System Movement Limits for Real-Time Simulator Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current motion simulators face challenges in determining movement limits in real-time due to the non-deterministic and iterative methods used for calculating system boundaries, which are not capable of providing accurate movement space limits within the required time frame for real-time control.

Innovation Solution

A method that determines the movement limit by calculating the maximum possible position of upper joint points on their joint trajectories, considering the current movement system state and mechanical limitations, allowing for deterministic and real-time calculation of movement limits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If iterative methods are used to determine movement limits, then comprehensive system boundary analysis is achieved, but real-time calculation capability is lost

Engineering Contradiction:
Improvemovement limit accuracyVSAvoidcalculation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent pre-calculates and stores the relationship between actuator lengths and platform positions in lookup tables during system initialization. This preliminary action allows the control system to quickly retrieve movement limits without performing iterative calculations in real-time, thus achieving both accuracy and speed requirements.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates simplified mathematical models that approximate the complex iterative calculations. By using pre-computed lookup tables and simplified formulas that replicate the essential behavior of the full iterative model, the system achieves real-time performance while maintaining sufficient accuracy for control purposes.

Inventive Principle:
Principle #26Copying

2Speed

If direct forward kinematics control is used, then real-time control responsiveness is improved, but system state feedback accuracy deteriorates

Engineering Contradiction:
Improvecontrol responsivenessVSAvoidsystem state accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where the actual platform position and orientation are continuously measured using sensors (such as encoders on actuators and inertial measurement units). These feedback signals are used to correct deviations from the commanded positions, ensuring accurate system state knowledge while maintaining real-time control responsiveness.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces intermediate calculation steps that bridge direct forward kinematics and accurate system state determination. By using pre-computed transformation matrices and lookup tables as intermediaries, the system can quickly convert actuator lengths to platform poses while maintaining accuracy through pre-validated mathematical relationships.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3023205B1Method for determining a movement limit
Publication Date: 2022.02.23 DEUTSCHES ZENTRUM FÜR LUFT UND RAUMFAHRT E V
  • EP3023205B1 patent drawingFigure 1a
  • EP3023205B1 patent drawingFigure 1b
  • EP3023205B1 patent drawingFigure 2

AI summary

The invention relates to a method for determining the movement limit of a motion system, wherein first a degree of freedom of the motion system for which the movement limit is to be determined is defined and the respective current state of the motion system is provided. Subsequently, a joint trajectory is determined for each upper joint point of the motion system, along which the joint point can move along the degree of freedom. By calculating the intersection point of the actuator movement at an extreme deflection with its respective joint trajectory, the movement limit can then be derived.