Adaptive Drive Machine Speed Control for Turbocharged Engines

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Solution Overview

Problem

Existing drive systems for mobile work machines, such as excavators and cranes, face inefficiencies in fuel consumption and response behavior due to fixed or proportional speed settings that do not adapt to actual power requirements, particularly influenced by turbocharged internal combustion engines and boost pressure.

Innovation Solution

A method for specifying a variable and adaptive setpoint speed for the drive machine based on the evaluation of current and predicted system states, including a base speed and an offset speed calculated from expected changes in power requirements, allowing early anticipation and adjustment of engine speed to meet dynamic demands while optimizing fuel efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a fixed or proportional speed setting is used for the drive machine, then the control system is simple to operate, but fuel consumption increases and response behavior deteriorates

Engineering Contradiction:
Improvecontrol system simplicityVSAvoidfuel consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The control device anticipates future power requirements by predicting the operator's intended actions based on current input device positions. It calculates a predicted setpoint power that represents future demands, allowing the drive machine to prepare in advance by adjusting speed before the actual load change occurs. This preliminary action enables the engine to build up boost pressure proactively, improving response behavior without requiring complex real-time reactions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a dynamic speed control strategy that continuously adapts the drive machine's operating speed based on predicted power requirements. Instead of fixed or simple proportional control, the system dynamically adjusts speed to match anticipated load demands, optimizing the balance between fuel efficiency and response performance. The control device modulates speed proactively based on predicted setpoint power, creating a dynamic response that anticipates rather than reacts to load changes.

Inventive Principle:
Principle #15Dynamics

2Speed

If the drive machine speed is increased to improve response behavior, then system dynamics improve, but fuel consumption increases

Engineering Contradiction:
Improvedrive machine speedVSAvoidfuel consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The control device increases speed in advance of actual load demands by predicting future power requirements. This proactive speed increase allows the engine to build up boost pressure before the load actually increases, improving response behavior. After the load change occurs, the speed is reduced since the accumulated kinetic energy and boost pressure maintain system performance. This timing optimization achieves good response behavior without sustained high-speed operation, reducing overall fuel consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent dynamically changes the operating parameters of the drive machine, specifically the speed, based on predicted power requirements. The control device adjusts speed as a variable parameter rather than maintaining a fixed value, optimizing the balance between response behavior and fuel consumption. By modulating speed according to predicted setpoint power, the system achieves improved dynamics only when necessary, rather than operating at constantly elevated speeds.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If a proportional speed specification based on input device actuation is used, then the control adapts to power requirements, but response behavior deteriorates due to turbocharged engine characteristics

Engineering Contradiction:
Improvespeed adaptation to power requirementsVSAvoidresponse behavior
Core Design Contradiction:
Adaptability or versatilityVSSpeed

Solution Approach 1:

The control device overcomes the inherent lag of turbocharged engines by taking preliminary action. It predicts future power requirements based on current input device positions and proactively adjusts speed before the actual load change occurs. This allows the engine to build up boost pressure in advance, compensating for the turbocharger's delayed response. The system doesn't wait for the load change to manifest but anticipates it, thereby improving response behavior while maintaining adaptive speed control.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a dynamic control strategy that goes beyond simple proportional adaptation. The control device continuously predicts future power requirements and dynamically adjusts speed accordingly, creating a proactive rather than reactive control system. This dynamic approach anticipates load changes and adjusts engine operation in advance, overcoming the inherent sluggishness of turbocharged engines while maintaining adaptability to varying power requirements.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2420423B1Method for determining a rotational speed of a drive machine of a drive system
Publication Date: 2013.03.27 ROBERT BOSCH GMBH
  • EP2420423B1 patent drawingFigure 1
  • EP2420423B1 patent drawingFigure 2~3

AI summary

The method involves determining the predetermined rotational speed of the prime mover depending on the current system state and the predicted system state of the drive system (1). A system model of the drive system is used to determine the predicted system state. An independent claim is also included for a calculating unit for executing the method.