Walk-Behind Mower Propulsion Control via Angular Velocity Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Walk-behind machines, such as lawnmowers, lack efficient automatic control over drive speed, particularly during transitions between cutting rows, leading to operator fatigue and reduced efficiency.
Innovation Solution
A propulsion system with a sensor array and controller that measures angular velocities about different axes, allowing the drive transmission to adjust speed automatically, including the option to terminate propulsion when specific dynamic conditions are met, such as tilting and turning, to reduce speed and conserve energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the drive assembly maintains continuous propulsion at high speed, then productivity is improved, but operator fatigue increases and safety decreases during transitions
Solution Approach 1:
The system automatically detects transition conditions through sensor arrays measuring angular velocities and accelerations, then autonomously adjusts drive assembly operation without operator intervention. The controller monitors sensor data and automatically places the drive assembly in off-state during transitions, eliminating the need for manual speed adjustment and reducing operator fatigue while maintaining productivity.
2Productivity
If the drive assembly operates at high speed continuously, then productivity is improved, but energy consumption increases during unnecessary propulsion
Solution Approach 1:
The system employs sensor arrays that continuously monitor angular velocities about multiple axes and acceleration data to detect machine orientation and motion state. This feedback is processed by the controller, which compares sensor readings against threshold criteria to determine when transitions are occurring. When transition conditions are met, the controller automatically adjusts drive assembly operation to conserve energy while maintaining productivity during actual mowing operations.
3Ease of operation
If the drive assembly automatically adjusts speed during transitions, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The sensor array serves multiple functions: measuring angular velocities about different axes, detecting machine orientation, identifying transition conditions, and providing data for automatic control decisions. The controller integrates these functions by processing sensor data uniformly against predefined thresholds to manage drive assembly operation. This multi-functional approach improves ease of operation through automatic control while managing complexity by consolidating functions rather than adding separate systems for each measurement.
Data Source
AI summary
A propulsion control system for a walk-behind self-propelled machine including a drive transmission and at least one wheel selectively driven by the drive transmission can include a sensor array and a controller. The sensor array can be configured to measure a first angular velocity about a first rotational axis of the machine and a second angular velocity about a second rotational axis of the machine, where the second rotational axis is different from the first rotational axis. The controller can be in electrical communication with the sensor array and configured to place the drive transmission in an off state when the drive transmission is in an on state, the first angular velocity is greater than a first threshold, and the second angular velocity is greater than a second threshold.