Construction Machine Engine Diagnosis Under Stable Pump Load

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Solution Overview

Problem

Existing engine diagnosing technologies for construction machines like hydraulic excavators and cranes face challenges in accurately determining engine degradation due to varying work loads and require significant data processing and communication costs, leading to uncertainty and high costs in diagnosing engine output power reductions.

Innovation Solution

A construction machine equipped with a controller that validates diagnosis data by determining a preset loaded state of the hydraulic pump, using torque command values for speed sensing control, and generates time history data for engine diagnosis, reducing data volume and suppressing measurement errors to improve accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If frequency distribution information is accumulated over a long period to detect engine degradation, then the diagnosis accuracy is improved, but the data volume and communication costs increase significantly

Engineering Contradiction:
Improveengine degradation diagnosis accuracyVSAvoiddata volume
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the necessary diagnostic information (engine output power and frequency distribution) from the collected data, transmitting only these essential parameters to the server rather than transmitting all raw sensor data. This extraction principle reduces communication data volume while preserving diagnostic accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The controller performs preliminary processing of frequency distribution information locally before transmission, calculating and preparing the data in advance. This preliminary action reduces the complexity and volume of data that needs to be transmitted and processed remotely.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If frequency distribution information is accumulated over a long period to detect engine degradation, then the diagnosis accuracy is improved, but the communication costs increase

Engineering Contradiction:
Improveengine degradation diagnosis accuracyVSAvoidcommunication cost
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The patent extracts only the necessary diagnostic information (engine output power and frequency distribution) from the collected data, transmitting only these essential parameters to the server rather than transmitting all raw sensor data. This extraction principle reduces communication data volume while preserving diagnostic accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of information

If all collected data is transmitted to the server for processing, then the comprehensive analysis is improved, but the communication cost and data transmission burden increase

Engineering Contradiction:
Improvecomprehensive analysis capabilityVSAvoidcommunication cost
Core Design Contradiction:
Loss of informationVSLoss of energy

Solution Approach 1:

The patent extracts only the necessary diagnostic information (engine output power and frequency distribution) from the collected data, transmitting only these essential parameters to the server rather than transmitting all raw sensor data. This extraction principle reduces communication data volume while preserving diagnostic accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The controller performs preliminary processing and selection of diagnostic data locally before transmission, serving itself by pre-processing the data. This self-service approach reduces the communication burden while ensuring that the most relevant information is transmitted for comprehensive analysis.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3859091B1Construction machine
Publication Date: 2026.03.25 HITACHI CONSTRUCTION MACHINERY CO LTD
  • EP3859091B1 patent drawingFigure 1
  • EP3859091B1 patent drawingFigure 2
  • EP3859091B1 patent drawingFigure 3

AI summary

A cost required to perform the diagnosis of the degradation such as a reduction in output power of an engine while engine degradation diagnosis accuracy is improved. To this end, a controller 37 (engine diagnosing device) determines whether a hydraulic pump 12 is in a preset loaded state (an operation scene where a load torque of the hydraulic pump 12 is in a stable state) for acquiring diagnosis data of an engine 10, and validates a controlled variable related to a torque command value Ta of speed sensing control as the diagnosis data of the engine 10 when it is determined that the hydraulic pump 12 is in the present loaded state, generates time history data using this validated controlled variable as a current feature variable, and enables this time history data to be displayed as trend data for engine diagnosis on a display device 38.