Piston Engine Speed Controller Adaptive Oscillation Mitigation

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Solution Overview

Problem

Existing speed controllers for piston engines face challenges in maintaining stable engine speed due to oscillations caused by changes in engine conditions, such as wear and tear, varying load, and environmental factors, leading to potential damage from excessive stress on flexible couplings.

Innovation Solution

A speed controller with a monitoring section that analyzes oscillations and generates control signals to mitigate harmful oscillations, using interfaces to receive and transmit data, and employing filters, computation, comparison, and selection elements to determine and respond to variance in engine speed, allowing for adaptive control without detailed engine modeling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the controller is tuned to respond rapidly to changes in engine load, then the response speed is improved, but the engine speed oscillates more at stable speed

Engineering Contradiction:
Improveresponse speedVSAvoidengine speed stability
Core Design Contradiction:
SpeedVSStability of the object's composition

Solution Approach 1:

The patent implements dynamic retuning of controller parameters based on operating conditions. The monitoring section continuously analyzes engine responses and adjusts controller parameters in real-time, transforming the static controller into a dynamic system that adapts to changing conditions. This resolves the contradiction by allowing rapid response when needed while maintaining stability during steady operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes controller parameters dynamically based on monitored engine responses. By analyzing variance in engine speed and adjusting controller gain and other parameters accordingly, the system optimizes the balance between response speed and stability. This parameter adaptation resolves the fixed-tuning limitation that causes oscillation-stability trade-offs.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If the controller is tuned to eliminate oscillation of engine speed at stable speed, then the stability is improved, but the response to changes in engine load becomes slow

Engineering Contradiction:
Improveengine speed stabilityVSAvoidresponse speed
Core Design Contradiction:
Stability of the object's compositionVSSpeed

Solution Approach 1:

The monitoring section dynamically adjusts controller parameters based on real-time engine response analysis. When the engine operates at stable speed, parameters are tuned to minimize oscillation. When load changes occur, parameters are adjusted to improve response speed. This dynamic adaptation resolves the contradiction between stability and response speed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes controller parameters based on operating conditions and monitored responses. By analyzing engine speed variance and adjusting parameters like gain and integral time, the controller optimizes performance for each operating regime, achieving both stability during steady operation and rapid response during transients.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If traditional PID controller tuning is used, then the device complexity is low, but the controller cannot adapt to changing engine conditions such as wear and tear, leading to increased oscillation or slower response

Engineering Contradiction:
Improvecontroller structureVSAvoidadaptation to changing conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent introduces a monitoring section that continuously measures engine speed and analyzes the controller's effect on engine responses. This feedback loop provides information about actual engine behavior under current conditions, enabling the controller to adapt to changes like wear and tear without increasing overall system complexity significantly.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The controller performs self-diagnosis and self-adjustment by monitoring its own output effects on engine speed. The monitoring section analyzes engine responses to controller actions and automatically retunes parameters, allowing the system to adapt to changing conditions without external intervention or complex modeling.

Inventive Principle:
Principle #25Self-service

4Speed

If the speed controller causes oscillations at resonant frequency, then the control responsiveness is improved, but the flexible coupling experiences excessive stress and may break

Engineering Contradiction:
Improvecontrol responsivenessVSAvoidstress on flexible coupling
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The monitoring section analyzes engine responses to predict when controller actions might excite resonant frequencies. By detecting patterns in engine speed variance and anticipating harmful oscillations, the system takes preliminary action to adjust parameters before excessive stress occurs on the flexible coupling, preventing damage while maintaining control effectiveness.

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP2247840B1Speed controller for piston engine
Publication Date: 2019.05.01 WARTSILA FINLAND OY
  • EP2247840B1 patent drawingFigure 1~2
  • EP2247840B1 patent drawingFigure 3~4
  • EP2247840B1 patent drawing

AI summary

The invention reduces oscillations in the rotational speed of an engine caused by the speed controller. This is achieved through a piston engine speed controller that can analyse the oscillations it is causing and take the necessary action on this basis. The action may constitute the generation and transmission of a message to a monitoring unit, or adjustment of the speed control to reduce oscillation. The speed controller has a monitoring section (10) for monitoring the responses in engine speed caused by the actions of the speed controller (4). The monitoring section is arranged to generate a control change signal to control the speed controller (4) as necessary, and to generate a message regarding the response caused by controller operation as necessary.