Electric Table Vibration Sensor Control for Anti-Pinch Safety

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Solution Overview

Problem

Existing electric tables have low accuracy and insufficient sensitivity in detecting inclination angles due to the use of high-precision angle detecting units, leading to high costs and ineffective anti-pinch systems.

Innovation Solution

A control unit for electric tables that combines a vibration sensor unit with an acceleration sensor and a gyroscope sensor, where the gyroscope measures rotational angular velocity and corrects the output of the acceleration sensor, enabling stable data within a preset range, and includes a current sensor to detect excessive power mechanism current, triggering an anti-pinch action when thresholds are exceeded.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If high-precision angle detecting units are used to detect the inclination angle of the table body, then the measurement precision is improved, but the device complexity and cost increase

Engineering Contradiction:
Improveinclination angle detection accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines acceleration sensors and gyroscope sensors into a unified detection system. The acceleration sensor detects gravitational acceleration components to determine table inclination, while the gyroscope provides angular velocity data for correction. By merging these two sensor types and processing their combined output, the system achieves high-precision inclination detection without requiring expensive high-precision angle detecting units alone.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces traditional mechanical high-precision angle detecting units with an electronic sensor fusion system. Instead of using mechanical inclinometers or precision encoders, the system uses acceleration sensors and gyroscopes with electronic signal processing to achieve equivalent or superior measurement precision, thereby reducing device complexity and cost.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If traditional inclination angle detection methods are used, then the device complexity is reduced, but the measurement precision and sensitivity are insufficient

Engineering Contradiction:
Improvedetection system complexityVSAvoidinclination angle detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements feedback correction using gyroscope data. The gyroscope detects angular velocity during table movement and provides correction signals to compensate for drift and errors in the acceleration sensor measurements. This feedback mechanism enhances measurement precision and sensitivity while maintaining relatively simple device complexity, as the correction is performed through software processing rather than additional hardware.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the detection parameters by using acceleration sensors to measure gravitational acceleration components along different axes and gyroscopes to measure angular velocity. By processing these parameter changes through coordinate transformations and fusion algorithms, the system achieves high-precision inclination detection with simpler and less expensive sensors compared to traditional high-precision angle detecting units.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the safety mode is triggered only when inclination angle exceeds a threshold, then the false triggering is reduced, but the sensitivity to obstacles is insufficient

Engineering Contradiction:
Improvefalse triggering rateVSAvoidobstacle detection sensitivity
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary detection of abnormal states using acceleration sensors before the table reaches significant inclination angles. The acceleration sensor can detect unexpected acceleration patterns or vibrations that indicate obstacle contact even when the overall table inclination remains small. This preliminary action allows the system to trigger safety mode earlier and more accurately, improving obstacle detection sensitivity without increasing false triggering.

Inventive Principle:
Principle #10Preliminary action

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 solution enhances the sensitivity and accuracy of inclination detection, allowing for a more effective anti-pinch mechanism with reduced costs, as the gyroscope's sensitivity to vibration enables real-time detection and control of the table's movement, improving safety and reducing the anti-pinch force to about 10 kg.

Implementation Method 1

the gyroscope sensor measures a physical quantity, i.e., rotational angular velocity when deflecting and tilting

Methodology Applied
Scientific EffectGyroscope: Gyroscope

Implementation Method 2

the acceleration sensor and the gyroscope sensor work simultaneously

Methodology Applied
Scientific EffectAcceleration sensor: Accelerometer

Data Source

PatentEP3878312B1Unit for controlling safe operation of an electric table
Publication Date: 2024.04.17 CHANGZHOU KAIDI ELECTRICAL INC
  • EP3878312B1 patent drawingFigure 1
  • EP3878312B1 patent drawingFigure 2
  • EP3878312B1 patent drawingFigure 3

AI summary

The invention provides a method for controlling safe operation of an electric table, comprising: starting the default setting value or self-set setting value of the sensor unit stored in the memory after power-on; making sure that the electric control module activates the sensor unit when the electric table is raised or lowered, and the sensor unit detects the vibration amplitude of the electric table and records the number of vibrations when the vibration amplitude exceeds the setting value; when the recorded number of vibrations is greater than the default setting value or self-set setting value, the electric control module controls the power mechanism on the electric table to make a rebound action in the opposite direction when the electric table is raised or lowered. The acceleration and gyroscope sensors are vertically installed on the small board, so that the sensitivity of the gyroscope to vibration detection is increased.