Micrometer Origin Setting Using Force Feedback and Encoder Zeroing

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Solution Overview

Problem

Existing small-sized adjustable measuring force devices rely on human reaction speed to set the origin, leading to imprecise measurements due to potential over-rotation of the thimble after detecting the predetermined measuring force, which affects the accuracy of workpiece measurement.

Innovation Solution

A small-sized measurement device equipped with an encoder and a central control unit that automatically sets the origin by detecting contact at a predetermined pressure through a measuring force switch, allowing for precise zero-point setting independent of human reaction speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If automatic origin setting is implemented, then measurement precision is improved, but device complexity increases

Engineering Contradiction:

Improveorigin setting precisionVSAvoidcontrol system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses feedback from the measuring force switch to detect when the predetermined force is applied, and the encoder provides continuous position feedback to the central control unit. This feedback mechanism enables automatic origin setting by monitoring the relationship between applied force and spindle position, resolving the contradiction by using sensor feedback to achieve precision without manual intervention.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs self-service through automatic origin setting where the central control unit autonomously determines the origin point based on encoder position data and measuring force switch signals. The device serves itself by automatically resetting the counter to zero when contact is detected, eliminating the need for manual origin setting operations while maintaining high precision.

Inventive Principle:

Principle #25Self-service

2Device complexity

If manual origin setting is used, then device complexity is reduced, but measurement precision deteriorates due to human reaction speed limitations

Engineering Contradiction:

Improvecontrol system complexityVSAvoidorigin setting precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces the manual mechanical origin setting process with an automated electronic control system. The central control unit uses encoder position signals and measuring force switch signals to automatically determine and set the origin, substituting human reaction-based mechanical operation with electronic detection and automatic control, thereby achieving higher precision while managing device complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If the thimble is rotated quickly to save time, then productivity is improved, but measurement precision deteriorates due to over-rotation

Engineering Contradiction:

Improveorigin setting speedVSAvoidorigin setting precision

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The feedback mechanism continuously monitors the spindle position via the encoder and the applied force via the measuring force switch. This real-time feedback allows the system to automatically detect the exact moment when the predetermined force is applied and immediately reset the origin, enabling fast origin setting without over-rotation. The system can operate quickly while maintaining precision because the electronic feedback loop responds instantaneously to force application.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The automatic origin setting system performs self-service by autonomously detecting the contact point and resetting the counter without requiring careful manual control. The central control unit automatically manages the origin setting process based on sensor inputs, enabling rapid operation while eliminating the precision loss associated with manual thimble rotation speed control.

Inventive Principle:

Principle #25Self-service

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 precise and automatic setting of the origin, ensuring accurate measurements by automating the process of detecting contact pressure and ending the origin setting mode once the predetermined force is applied, thus improving measurement precision.

Implementation Method 1

an encoder that detects a position of the movable member

Methodology Applied

Scientific EffectEncoder detection:

Implementation Method 2

a measuring force detecting means for detecting that the movable member is brought into contact with the object to be measured at a predetermined pressure

Methodology Applied

Scientific EffectPressure sensing:

Data Source

PatentUS10996043B2Method for controlling small-sized measurement device

Publication Date: 2021.05.04 MITUTOYO CORP

AI summary

There is provided a method for controlling a small-sized adjustable measuring force measurement device capable of appropriately setting the origin.A central control unit changes an operation mode to an origin setting mode in response to predetermined mode changing operation. The central control unit sets a counter value of an encoder to zero as an origin when a measuring force detecting means detects that a movable member is brought into contact with an object to be measured at a predetermined pressure in the origin setting mode.