Crane Hybrid Power Transmission Control for Gear-Dependent Torque Buffering

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Solution Overview

Problem

Current power transmission control methods for wheeled cranes with oil-hydraulic hybrid power systems fail to effectively manage torque control across different gears, leading to power impact, reduced driving comfort, and safety concerns due to unreasonably distributed braking and driving forces, as well as neglecting the crane's high inertia and multiple gear configurations.

Innovation Solution

A power transmission control method and device that determines the current gear state and specific gear of the crane, calculates the maximum allowable displacement of the secondary element, and incorporates a buffer mode during energy release and recovery to stabilize power output, reducing power impact and improving driver comfort and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the hydraulic system is applied to a multi-gear vehicle with large difference of gear speed ratios, then the hybrid power system can provide strong driving force, but large difference of required torques between gears causes power impact and reduces driving comfort

Engineering Contradiction:
Improvedriving forceVSAvoiddriving comfort
Core Design Contradiction:
PowerVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the secondary element's displacement adjustable and gear-dependent. The control device dynamically adjusts the maximum displacement of the secondary element according to the current gear, allowing the system to adapt to different torque requirements of each gear ratio, thereby reducing power impact while maintaining strong driving force capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of secondary element displacement based on gear state. By setting different maximum displacement values for different gears, the system optimizes the balance between power output and smooth operation, reducing the harshness caused by large torque differences across gears.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the secondary element operates without gear-based displacement control, then the system structure remains simple, but power impact occurs during energy storage and release due to sudden torque changes

Engineering Contradiction:
Improvesystem structureVSAvoidpower stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The control device performs preliminary action by pre-setting the maximum displacement of the secondary element according to the current gear before energy storage or release operations. This prevents sudden torque changes and power impact, ensuring smooth power transitions while maintaining relatively simple system structure.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If the secondary element displacement is not limited by gear state, then the control algorithm is simple, but the service life of the hybrid power system is reduced due to excessive power impact

Engineering Contradiction:
Improvecontrol algorithmVSAvoidservice life
Core Design Contradiction:
Device complexityVSDuration of action of stationary object

Solution Approach 1:

The patent makes the control algorithm adaptive to gear state by dynamically adjusting the secondary element's maximum displacement based on current gear. This reduces power impact that would otherwise damage the hybrid power system, extending its service life while keeping the control logic relatively straightforward through gear-based displacement limits.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3231651B1Power transmission control method and device for crane, and crane
Publication Date: 2024.08.28 XUZHOU HEAVY MASCH CO LTD
  • EP3231651B1 patent drawingFigure 1
  • EP3231651B1 patent drawingFigure 2
  • EP3231651B1 patent drawingFigure 3

AI summary

The present invention discloses a power transmission control method and device for a crane and the crane. The method includes: setting the maximum working displacement of a secondary element corresponding to each gear of the crane; determining the current gear state and specific gear of the crane; determining the working mode of the secondary element from the gear state, and setting the maximum allowable displacement of the secondary element as the maximum working displacement corresponding to the specific gear. According to the power transmission control method and device for the crane and the crane of the present invention, the maximum displacement of the secondary element is controlled for various gears, which can reduce power impact. A buffer mode is added to avoid influence on a vehicle due to loss of instant power generated at the moment of energy release completion and avoid vehicle jitter due to instable power resulting from the vehicle at low speed or a system suddenly disconnected, thus improving the comfort and safety of a driver, and the rotating speed of the secondary element is limited, which can improve the service life and energy recovery efficiency of the secondary element.