Control Device Trainable Error Compensation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing control devices struggle to accurately compensate for periodic disturbances, such as those caused by inertial or machining forces in machine tools, which affect the control quality significantly and are not precisely implemented by manufacturers.

Innovation Solution

A control device design that includes a compensation circuit with a frequency filter, buffer memories, and adjustable weighting factors, which forms a compensation signal by tapping the control difference and feedback signal, and filters it to align with the disturbance period, ensuring stable regulation by adjusting parameters to maintain amplification within safe limits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a compensation circuit with frequency filter and buffer memories is introduced to compensate periodic disturbances, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improvecontrol qualityVSAvoidcontrol device structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The compensation circuit is nested within the existing control device structure. The frequency filter and buffer memories are integrated into the control signal path between the front node and rear node, with the compensation circuit receiving the control difference and feeding back a compensation signal. This nesting approach allows the compensation function to be added without completely redesigning the control device, thereby improving manufacturing precision while limiting the increase in device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The buffer memories store historical control difference signals from previous disturbance periods, preparing compensation data in advance. The frequency filter pre-processes these stored signals to extract periodic disturbance characteristics before they are fed back as compensation signals. This preliminary action allows the system to proactively compensate for periodic disturbances, improving control quality while using a structured approach that manages device complexity.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the compensation circuit parameters are precisely adjusted to match disturbance period, then manufacturing precision is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvedisturbance compensation accuracyVSAvoidparameter adjustment complexity
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The compensation circuit uses feedback from the control difference signal to automatically adjust and optimize compensation parameters. The frequency filter continuously analyzes the periodic disturbance characteristics in the feedback loop, and the buffer memories store historical data for parameter optimization. This feedback mechanism enables the system to self-tune to match the disturbance period, improving manufacturing precision while reducing the need for manual parameter adjustment and thereby improving ease of operation.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2988181B1Control device with trainable error compensation
Publication Date: 2019.07.03 SIEMENS AG
  • EP2988181B1 patent drawingFigure 1~2
  • EP2988181B1 patent drawingFigure 3~4
  • EP2988181B1 patent drawingFigure 5

AI summary

A control device for regulating a controlled system (1) comprises a front node (2), a back node (3), a controller (4), and a compensation loop (5). The front node (2) receives an actual value (x) and a corresponding setpoint (x*) measured at the output of the controlled system (1). It calculates a control error (δx). The measured actual value (x) is subject to a disturbance (z). The back node (3) receives the control error (δx) and a compensation signal (K). It feeds an external summed signal, formed from the control error (δx) and the compensation signal (K), to the controller (4). The controller (4) calculates a control signal (S) for the controlled system (1) and outputs it to the controlled system (1). Between the front and rear nodes (2, 3) an external sampling point (7) is arranged, at which the control deviation (δx) is sampled and fed to the compensation circuit (5).