Lawn Mower Adaptive Mowing-Blade Speed Control for Low-Speed Energy Savings

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing riding-type lawn mowers face issues with maintaining lawn mowing quality and reducing unnecessary energy consumption due to excessive mowing-blade rotation speeds, especially at lower speeds.

Innovation Solution

A lawn mower system that adjusts the upper limit value of mowing-blade rotation speed based on the moving speed, using a controller to ensure the mowing-blade rotation speed does not exceed a predetermined limit, thereby preventing excessive rotation and conserving energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the mowing-blade rotation speed is maintained at a high constant speed, then the lawn mowing quality is improved, but the energy consumption increases unnecessarily when the vehicle moves at low speed

Engineering Contradiction:
Improvelawn mowing qualityVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the mowing-blade rotation speed variable rather than constant. The rotation speed is dynamically adjusted based on the vehicle's moving speed, allowing the system to adapt to different operating conditions. When the vehicle moves slowly, the blade speed is reduced to save energy; when the vehicle moves quickly, the blade speed increases to maintain cutting quality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of mowing-blade rotation speed based on the vehicle's moving speed parameter. By establishing a relationship between these two parameters (with an upper limit that decreases as vehicle speed decreases), the system optimizes energy consumption while maintaining adequate mowing quality across different operating speeds.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the mowing-blade rotation speed is reduced to save energy, then the energy consumption is reduced, but the lawn mowing quality deteriorates

Engineering Contradiction:
Improveenergy consumptionVSAvoidlawn mowing quality
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The system dynamically adjusts the mowing-blade rotation speed to match the vehicle's moving speed. This dynamic adjustment ensures that the blade speed is never excessively high when the vehicle is moving slowly, preventing wasted energy consumption while maintaining sufficient cutting speed for quality mowing when the vehicle is in motion.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent establishes a parameter relationship where the upper limit of mowing-blade rotation speed is tied to the vehicle's moving speed. This parameter coupling ensures that energy is not wasted on high-speed blade rotation when the vehicle is stationary or moving slowly, while still allowing high blade speeds when the vehicle moves quickly enough to justify the energy expenditure for quality cutting.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If a fixed upper limit value for mowing-blade rotation speed is set, then the control is simple, but the system cannot adapt to different vehicle speeds and causes unnecessary energy consumption

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

Solution Approach 1:

The patent implements a dynamic control system where the upper limit value of mowing-blade rotation speed is not fixed but varies with the vehicle's moving speed. This dynamic approach maintains relative simplicity in control logic while significantly reducing unnecessary energy consumption by lowering the speed limit when the vehicle moves slowly.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the control parameter (upper limit value of mowing-blade rotation speed) based on another parameter (vehicle moving speed). This parameter adaptation allows the control system to remain relatively simple while achieving energy efficiency through automatic adjustment of the speed limit according to actual operating conditions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4606200A1Lawn mower with cruise speed dependent adaptive mowing blade speed control and corresponding control method
Publication Date: 2025.08.27 KAWASAKI MOTORS LTD
  • EP4606200A1 patent drawingFigure 1
  • EP4606200A1 patent drawingFigure 2
  • EP4606200A1 patent drawingFigure 3

AI summary

The present invention relates to a lawn mower (1) including a vehicle main body (3), a traveling motor (9) provided in the vehicle main body, the traveling motor being configured to drive a traveling drive wheel (4) and a mowing-blade motor (15) provided in the vehicle main body, the mowing-blade motor being configured to rotationally drive a mowing-blade (14) for lawn mowing. The mower also includes an upper limit value output unit (13c) configured to output an upper limit value (L1, L2, L3) of a mowing-blade rotation speed (R0, R1, R2, R3). The upper limit value output unit outputs the upper limit value of the mowing-blade rotation speed lower as the moving speed (V1, V2, V3) of the lawn mower decreases. Thereby, it is possible to reduce power consumption while retaining an efficient cutting quality.