Position Control Method Using Linear Non-Linear Switching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing position control methods for drives often result in oscillations, overshoot, and transient processes due to unaccounted control limits and acceleration limitations, which are not effectively managed by current technologies.

Innovation Solution

A method that determines control values using linear operations below and above specific critical values, switching to non-linear operations to prevent exceeding maximum acceleration and undershooting minimum acceleration, allowing for predetermination of control limits without requiring state variables, using a characteristic curve that can be represented by a function for efficient memory usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If linear control operations are used for position control, then the control is simple and cost-effective, but control limits and acceleration limitations are not effectively managed, leading to oscillations and overshoot

Engineering Contradiction:
Improvecontroller structureVSAvoidcontrol stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The controller dynamically changes the control parameter (control value) based on the control deviation magnitude. When deviation is small, linear operations are used; when deviation exceeds critical values, non-linear operations are applied. This parameter-based switching resolves the contradiction by adapting the control strategy to the current system state, ensuring stability without requiring complex continuous control structures.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The control range is segmented into different zones based on critical values (upper and lower critical deviations). Each zone has a dedicated control strategy: linear control for normal operation and non-linear control for boundary conditions. This segmentation allows simple linear control to handle most cases while non-linear control manages edge cases, resolving the stability issue without overall complexity.

Inventive Principle:
Principle #1Segmentation

2Reliability

If non-linear control operations are used to manage acceleration limitations, then control limits and oscillations are reduced, but the control complexity increases

Engineering Contradiction:
Improveacceleration limitation complianceVSAvoidcontrol algorithm
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The controller dynamically switches between linear and non-linear operations based on real-time control deviation compared to critical values. This dynamic adaptation ensures acceleration limitations are met when needed (large deviations) while using simpler linear control during normal operation, resolving the contradiction between reliability and complexity through conditional application.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system automatically determines when to apply non-linear operations by comparing control deviation against predefined critical values. The system self-regulates its own complexity by activating non-linear control only when the deviation exceeds thresholds, eliminating the need for continuous complex control algorithms and resolving the contradiction autonomously.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If critical values are predetermined to limit acceleration, then overshoot and oscillations are reduced, but the flexibility in handling varying load conditions decreases

Engineering Contradiction:
Improveposition accuracyVSAvoidload condition adaptability
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

Critical values are predetermined based on system characteristics (maximum permissible acceleration, moment of inertia) before operation. This preliminary configuration ensures position accuracy by preventing overshoot and oscillations. The system maintains adaptability by using these fixed thresholds to trigger appropriate control responses regardless of varying load conditions, resolving the contradiction between precision and versatility.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2132606B1Method for controlling a position and drive
Publication Date: 2011.01.12 SEW EURODRIVE GMBH & CO KG
  • EP2132606B1 patent drawingFigure 1
  • EP2132606B1 patent drawingFigure 2
  • EP2132606B1 patent drawingFigure 3a

AI summary

Method for controlling a position and drive for moving an object, wherein a control error between the desired position and the actual position is determined, wherein the control value is determined from the control error by means of linear operations as long as the control error is below an upper critical value and above a lower critical value, and the control value is determined from the control error according to a non-linear function as long as the control error is above the upper critical value and below the lower critical value.