Electric Tool Shutdown Control Using Composite Load Averaging

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Solution Overview

Problem

Existing electric tools, such as handheld drills, face inefficiencies in automatic fastening operations due to high misjudgment rates in shutting down at preset positions across varying working conditions, as existing control solutions fail to accurately adapt to different conditions.

Innovation Solution

A control method for electric tools that involves calculating average values of output shaft load using a composite average algorithm, determining slope values, and interrupting torque output based on these calculations to accurately reflect the working condition and reduce misjudgment rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a simple average algorithm is used to calculate output shaft load, then the calculation is simple and fast, but the accuracy of shutdown control is low leading to high misjudgment rates

Engineering Contradiction:
Improveaccuracy of shutdown controlVSAvoidcomplexity of control algorithm
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the average calculation process into multiple stages: first calculating a first average value from initial current data, then calculating a second average value from subsequent data, and finally computing a composite average from these intermediate results. This segmentation allows the system to adapt to different working conditions at different stages, improving shutdown control accuracy without requiring an overly complex single-step algorithm.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic adaptation by using different average calculation strategies based on working conditions. The system transitions from a first average algorithm to a second average algorithm, and finally to a composite average algorithm, allowing the control method to dynamically adjust its complexity and precision based on the actual operating state, thereby reducing misjudgment rates while maintaining reasonable computational complexity.

Inventive Principle:
Principle #15Dynamics

2Reliability

If a composite average algorithm is used to calculate output shaft load, then the accuracy of shutdown control is improved, but the calculation complexity increases

Engineering Contradiction:
Improvereliability of automatic fastening operationVSAvoidcalculation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs preliminary calculations by first computing the first average value from initial current data before the fastening operation begins. This preliminary action prepares the system with baseline information, allowing the composite average algorithm to work more efficiently during the actual operation by comparing real-time data against pre-established references, thereby reducing overall calculation time while maintaining high reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent calculates not only the necessary composite average value but also intermediate first and second average values that can be used for different purposes. This partial/excessive calculation approach provides redundant information that improves reliability through multiple comparison points, while the systematic organization of these calculations prevents excessive time consumption by reusing intermediate results.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If the control method uses multiple average algorithms, then the adaptability to different working conditions is improved, but the device complexity increases

Engineering Contradiction:
Improveadaptability to different working conditionsVSAvoidcomplexity of control system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent changes the parameters of the average calculation algorithm based on working conditions. By switching between different average calculation methods (first average, second average, composite average) and adjusting the weighting and combination of these algorithms, the system adapts to varying load conditions, material types, and fastening requirements without requiring fundamentally different control systems for each scenario.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The composite average algorithm serves multiple functions: it provides baseline comparison data, enables real-time deviation detection, and offers a unified framework that handles various working conditions. This multi-functional approach allows a single control system to adapt to different scenarios (drilling, fastening, different materials) without requiring separate specialized algorithms for each case, thereby improving versatility while controlling overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS10962950B2Method and apparatus for controlling electric tool, and electric tool
Publication Date: 2021.03.30 POSITEC POWER TOOLS (SUZHOU) CO LTD
  • US10962950B2 patent drawing
  • US10962950B2 patent drawing
  • US10962950B2 patent drawing

AI summary

The present invention provides a control method and apparatus for an electric tool, and further provides an electronic tool, which relates to the field of automatic control of electric tools. The method comprises: Obtaining parameters characterizing an output shaft load during a running process of an electric tool; calculating the average values of the parameters characterizing an output shaft load according to a composite average algorithm, wherein the composite average algorithm comprises a combination of at least two average algorithms; calculating slope values of the parameters characterizing the output shaft load according to the average values of the parameters characterizing the output shaft load; and interrupting torque output of the electric tool according to the slope values of the parameters characterizing the output shaft load.