Hydrostatic Transmission Control for Stable Agricultural Vehicle Speed

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Solution Overview

Problem

Conventional agricultural work vehicles experience fluctuations in vehicle speed due to uneven ground conditions and workload changes, necessitating frequent manual adjustments to maintain constant-speed driving, which is inconvenient and delays work.

Innovation Solution

An agricultural work vehicle equipped with a hydrostatic transmission, a controller, sensors, and switches that automatically adjust the swash plate's rotational angle to maintain constant-speed driving by sensing load conditions and adjusting vehicle speed through a controller, allowing for simple switch manipulation to vary set vehicle speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a driver manually adjusts the foot pedal to maintain constant speed, then vehicle speed can be maintained, but driver convenience deteriorates and work efficiency decreases due to frequent manual adjustments

Engineering Contradiction:

Improveconstant-speed driving stabilityVSAvoiddriver convenience

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The system automatically detects load changes through sensors and adjusts the swash plate position without driver intervention. The controller monitors engine load conditions and autonomously modifies transmission parameters to maintain constant vehicle speed, making the system self-regulating and eliminating the need for manual pedal adjustments.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system employs sensors to continuously monitor load conditions and feeds this information back to the controller. Based on the feedback signal indicating load changes, the controller automatically adjusts the swash plate position to compensate for speed variations, creating a closed-loop control system that maintains constant velocity without driver input.

Inventive Principle:

Principle #23Feedback

2Reliability

If the swash plate position is fixed mechanically, then constant-speed driving is achieved, but adaptability to load changes deteriorates

Engineering Contradiction:

Improveconstant-speed drivingVSAvoidresponse to load changes

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system transitions from a fixed mechanical swash plate position to a dynamically adjustable position controlled by an electronic system. The swash plate can now be repositioned in real-time based on detected load conditions, allowing the transmission to adapt continuously to changing work demands while maintaining constant vehicle speed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent replaces the purely mechanical fixed-position swash plate system with an electronically controlled system. Sensors and controllers substitute for mechanical linkages, enabling automatic detection of load changes and electronic actuation of the swash plate to achieve both stability and adaptability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If the driver releases constant-speed mode to reset vehicle speed, then speed can be adjusted, but productivity deteriorates due to work delays

Engineering Contradiction:

Improvevehicle speed adjustmentVSAvoidwork efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The system automatically adjusts vehicle speed settings in response to load changes without requiring the driver to exit constant-speed mode. The controller autonomously modifies the target speed parameter based on sensor feedback, maintaining productive constant-speed operation while adapting to new working conditions.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system proactively detects load changes and pre-adjusts the vehicle speed parameter before the driver would need to intervene. By anticipating the need for speed adjustment and executing it automatically, the system prevents work interruptions and maintains continuous productive operation.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Minimizes speed fluctuations and reduces driver inconvenience by automatically adjusting vehicle speed based on load conditions, enhancing the vehicle's usability and reducing the likelihood of engine drops.

Implementation Method 1

The hydraulic motor generates rotational force on an output shaft through hydraulic pressure based on the flow rate of working fluid from the hydraulic pump.

Methodology Applied

Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

The hydraulic pump is equipped with a swash plate for gear shifting, and gear shifting is achieved by the rotation of the swash plate. The flow rate provided to the hydraulic motor is varied depending on the rotational angle of the swash plate.

Methodology Applied

Scientific EffectSwash plate mechanism: Swashplate

Data Source

PatentUS20260110359A1Agricultural work vehicle and control method therefor

Publication Date: 2026.04.23 LS MTRON LTD

AI summary

The present disclosure is directed to an agricultural work vehicle and a method of controlling the same. According to the present disclosure, a set vehicle speed may be varied while maintaining a constant-speed driving mode, and the control of the hydrostatic transmission is performed to maintain the set vehicle speed, thereby improving the convenience of use and utilization rate of an agricultural work vehicle.