Machine Tool Operating Mode Detection Using Acceleration Deflection

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Solution Overview

Problem

Existing machine tools lack a method to automatically detect operating modes without additional sensors, which is crucial for adapting functionalities based on stand-mounted or hand-held operation, especially in construction-site conditions where added sensors are undesirable due to dust and moisture risks and increased complexity.

Innovation Solution

The method determines the operating mode by analyzing varying deflections caused by axial and angular accelerations measured using a sensor, such as a gyroscope, and assigns these deflections to either manual or stand operation based on startup deflection values, utilizing existing data and measurements to adapt machine tool behavior accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an additional contact sensor is added to detect operating mode, then the detection capability is improved, but the device complexity increases and reliability decreases due to dust and moisture risks

Engineering Contradiction:
Improveoperating mode detection capabilityVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The existing acceleration sensor, originally designed for measuring vibrations and shocks during machine tool operation, is made multi-functional by also using it to detect operating mode. The sensor serves both its original vibration measurement function and the new function of determining whether the machine tool is in handheld or stand-mounted mode by analyzing acceleration patterns during startup and operation transitions.

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

Solution Approach 2:

The machine tool uses its own existing sensor infrastructure to detect operating mode without requiring external or additional sensors. The acceleration sensor already present in the system is repurposed to provide operating mode information, making the system self-sufficient and avoiding the need for separate detection components that would increase complexity and reduce reliability.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If an additional contact sensor is added to detect operating mode, then the detection capability is improved, but the reliability decreases due to dust and moisture risks

Engineering Contradiction:
Improveoperating mode detection capabilityVSAvoidsensor reliability in construction-site conditions
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The existing acceleration sensor, originally designed for measuring vibrations and shocks during machine tool operation, is made multi-functional by also using it to detect operating mode. The sensor serves both its original vibration measurement function and the new function of determining whether the machine tool is in handheld or stand-mounted mode by analyzing acceleration patterns during startup and operation transitions.

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

Solution Approach 2:

The machine tool uses its own existing sensor infrastructure to detect operating mode without requiring external or additional sensors. The acceleration sensor already present in the system is repurposed to provide operating mode information, making the system self-sufficient and avoiding the need for separate detection components that would increase complexity and reduce reliability.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If the machine tool adapts functionalities based on detected operating mode, then the adaptability is improved, but the device complexity increases

Engineering Contradiction:
Improvefunctionality adaptation to operating modeVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The machine tool's control system is made dynamic by enabling automatic adaptation of functionalities based on detected operating mode. Parameters such as switch device behavior, potentiometer functions, and operational limits are dynamically adjusted according to whether the machine tool is detected to be in handheld or stand-mounted mode, allowing the system to optimize its performance characteristics for each operating condition.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system implements feedback by continuously monitoring acceleration sensor data to determine operating mode and automatically adjusting system parameters accordingly. The detected operating mode feeds back into the control logic, which then modifies functionalities such as switch behavior and operational parameters, creating a closed-loop system that adapts to the current operating conditions.

Inventive Principle:
Principle #23Feedback

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

Enables reliable automatic detection of operating modes, allowing the machine tool to adapt its functionalities and parameters based on detected operation, enhancing robustness and usability without requiring additional sensors.

Implementation Method 1

The inventor recognized that, due to the inertia of the drilling system, which preferably comprises a motor, a shaft, a gearbox, and a tool, the deflection when starting the motor in manual operation is significantly greater than the deflection in a drill stand.

Methodology Applied
Scientific EffectInertia: Inertia

Data Source

PatentEP4196855B1Machine tool and method for detecting the operating mode of a machine tool
Publication Date: 2025.12.31 HILTI AG
  • EP4196855B1 patent drawingFigure 1

AI summary

The present invention relates to a method for detecting an operating mode of a machine tool. In a further aspect, the invention relates to a machine tool comprising a sensor for detecting axial accelerations and/or angular accelerations, wherein the machine tool is configured to carry out the proposed method.