Power Tool Free-Fall Detection With Timed Motor Autostop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power tools lack effective methods to detect free-fall and prevent motor operation during a drop, which can lead to premature motor stoppage and operational inefficiencies.
Innovation Solution
A system comprising a power tool with a motor, a sensor to measure acceleration, and a controller that compares acceleration to free-fall thresholds, initiating a timer and stopping the motor only when the timer exceeds a predetermined threshold, thereby preventing premature motor stoppage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the motor is stopped immediately when free-fall acceleration threshold is detected, then safety is improved, but false positive stoppage occurs during normal operation
Solution Approach 1:
The system initiates a timer when the acceleration threshold is first exceeded, preparing the motor stoppage in advance but delaying actual execution until the timer confirms sustained free-fall conditions. This preliminary timing action distinguishes between transient vibrations and genuine free-fall events, preventing false positives while maintaining safety response capability.
2Productivity
If a timer threshold is added to confirm free-fall before stopping the motor, then false positive stoppage is reduced, but response time to actual free-fall increases
Solution Approach 1:
The timer threshold is set to a value that is sufficient to filter false positives but not excessively long to cause unacceptable delay. By calibrating the timer to detect the minimum sustained duration of genuine free-fall events, the system achieves optimal balance between preventing false stoppages and maintaining rapid response to actual safety hazards.
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
The system effectively detects free-fall and prevents motor operation during a drop, ensuring safety and operational efficiency by distinguishing between free-fall and normal device movement.
Implementation Method 1
a sensor configured to measure an acceleration of the power tool and generate an output signal related to the acceleration
Data Source
AI summary
A power tool including a motor configured to produce an output, and a sensor configured to measure an acceleration of the power tool along at least one of three spatial axes and generate an output signal related to the acceleration. The power tool further including a controller configured to receive the output signal related to the acceleration of the power tool from the sensor, compare the acceleration of the power tool to a free-fall acceleration threshold, initiate a timer when the acceleration of the power tool corresponds to the free-fall acceleration threshold, compare the timer to a free-fall timer threshold, and stop the motor from producing the output when the timer is greater than or equal to the free-fall timer threshold.