Power Tool Bind-Up Control With Adaptive Motion Thresholds
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Solution Overview
Problem
Power tools experience bind-up conditions due to the drill bit or driver getting stuck, leading to increased voltage and current draw, which can damage the battery and motor, and existing systems lack effective methods to prevent or mitigate these events.
Innovation Solution
A controller system in the power tool adjusts rotational motion thresholds based on sensor inputs, including proximity and motion sensors, to detect potential bind-up conditions and initiate protective operations such as braking or throttling the motor to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed rotational motion threshold is used to detect bind-up events, then the detection system is simple to implement, but it cannot adapt to varying operating conditions such as battery fetting events or bracing, leading to false positives or missed detections
Solution Approach 1:
The patent implements dynamic threshold adjustment by modifying the rotational motion threshold based on detected operating conditions such as battery fetting events and bracing events. The controller continuously monitors sensor data and adjusts the threshold in real-time to match current operating conditions, transforming a static detection system into an adaptive one that maintains accuracy across varying scenarios.
Solution Approach 2:
The system employs feedback mechanisms where sensor data about operating conditions (battery status, motion patterns) is continuously fed back to the controller, which then adjusts the bind-up detection threshold accordingly. This closed-loop approach allows the system to learn from and respond to operating conditions, improving detection accuracy without requiring manual intervention.
2Measurement precision
If the rotational motion threshold is lowered to detect subtle bind-up conditions, then detection sensitivity increases, but false positives increase due to normal operational variations
Solution Approach 1:
The patent applies different threshold values for different operating conditions rather than using a single global threshold. By detecting the current operating state (e.g., bracing, battery fetting, normal operation), the system selects or adjusts the threshold locally appropriate for that condition, maintaining high sensitivity where needed while avoiding false positives in other contexts.
Solution Approach 2:
The system dynamically changes the detection threshold parameter based on operating conditions. When battery fetting or bracing is detected, the threshold is adjusted to account for the expected motion patterns during these events, preventing false bind-up detections while maintaining sensitivity to actual bind-up conditions when they occur.
3Reliability
If protective operations are initiated immediately upon detecting a bind-up condition, then motor and battery protection is maximized, but tool productivity is reduced due to frequent shutdowns
Solution Approach 1:
The system performs preliminary protective actions by adjusting operational parameters and thresholds before actual bind-up damage can occur. By detecting early signs of bind-up conditions and preemptively adjusting the threshold or initiating protective operations, the system prevents severe damage while minimizing disruption to tool operation, balancing protection with productivity.
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 prevents bind-up events by dynamically adjusting thresholds and responding with protective measures, reducing wear on the tool and ensuring user safety.
Implementation Method 1
a motion sensor configured to sense a rotational motion of the housing
Data Source
AI summary
Systems and methods for detecting and acting on bind-up conditions of a power tool. The power tool includes a housing, a motor, a battery pack, and a motion sensor configured to sense rotational motion of the housing. An electronic controller is connected to the motor, the battery pack, and the motion sensor. The electronic controller is configured to determine whether a battery fetting event is occurring and adjust a rotational motion threshold used to determine a bind-up event based on the battery fetting event. The electronic controller is further configured to receive, from the motion sensor, a first signal associated with a rotational motion of the housing, compare a value based on the signal to the rotational motion threshold, and initiate, in response to the value being greater than or equal to the rotational motion threshold, a protective operation.