Work Machine Engine Output Control for Excavation Fuel Efficiency

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Solution Overview

Problem

Work machines with increased engine output for reduced fuel consumption operate at excessively high outputs relative to load, worsening fuel efficiency.

Innovation Solution

A work machine with sensors and a controller that determines the work stage and adjusts engine output to a suitable level by reducing the upper limit during excavation, using a second control mode with a lower output than a first control mode for other work stages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the engine output is increased to reduce fuel consumption, then fuel consumption can be improved, but the engine operates at excessively high output relative to load and fuel consumption actually becomes worse

Engineering Contradiction:
Improvefuel consumptionVSAvoidenergy loss due to excessive output
Core Design Contradiction:
Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent applies dynamics by making the engine output adjustable and adaptive rather than fixed. The controller dynamically modifies the engine's output characteristics based on detected work stages, switching between a standard output characteristic and a modified output characteristic with reduced upper limit. This allows the engine to adapt its output to actual workload requirements, preventing excessive energy consumption while maintaining sufficient power for required tasks.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the engine output parameter based on work stage detection. When excavation work is detected, the controller changes the engine output parameter from the standard characteristic to a modified characteristic with a reduced upper limit. This parameter adjustment ensures the engine operates at appropriate output levels for each specific work type, optimizing fuel consumption by avoiding unnecessarily high output during excavation where lower output suffices.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the engine output is limited during low load work stages, then fuel consumption is reduced, but the engine may not have sufficient output when high load work is required

Engineering Contradiction:
Improvefuel consumptionVSAvoidengine output power
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The system dynamically adjusts engine output characteristics based on real-time detection of work stages. During low-load operations, the engine operates with reduced output to save fuel, while the capability to switch to standard output remains available when needed. This dynamic adaptation resolves the contradiction by providing both fuel efficiency during appropriate operations and sufficient power availability when required.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The controller prepares the engine output characteristics in advance for different work stages by detecting the current operation type. When excavation is detected, the controller preemptively adjusts the engine output to the modified characteristic with reduced upper limit. This preliminary action ensures the engine is already optimized for the detected work type before actual operation begins, preventing both excessive fuel consumption and power deficiency.

Inventive Principle:
Principle #10Preliminary action

3Power

If the engine operates at high output during excavation, then sufficient power is available for the heavy load, but fuel consumption increases

Engineering Contradiction:
Improveengine output powerVSAvoidfuel consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by modifying the engine output characteristic specifically for excavation work. Instead of using the standard high-output characteristic during excavation, the controller switches to a modified characteristic with a reduced upper limit that is tailored to the actual power requirements of excavation operations. This parameter optimization provides sufficient power for excavation while reducing fuel consumption by eliminating excessive output capacity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4585752A1Work machine and method for controlling work machine
Publication Date: 2025.07.16 KOMATSU LTD
  • EP4585752A1 patent drawingFigure 1
  • EP4585752A1 patent drawingFigure 2
  • EP4585752A1 patent drawingFigure 3

AI summary

A work machine includes a vehicle body, an engine, a travel device, a work implement, a sensor, and a controller. The sensor detects state data indicating operating states of the travel device and the work implement. The controller acquires the state data. The controller determines a work stage of the work machine based on the operating states of the travel device and the work implement. The controller controls the output of the engine in a first control mode when the work stage is determined as being predetermined work other than excavation. The controller controls the output of the engine in a second control mode when the work stage is determined as being excavation. The controller reduces the upper limit of the output of the engine in the second control mode to be lower than that of the first control mode.