Handle-Free Dishwasher Door Sensing for Vibration-Resistant Opening
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Solution Overview
Problem
Conventional dishwashers require significant operator force to open the door, and existing sensor-based systems are susceptible to interference signals, making reliable detection of the operator's intent to open the door challenging, especially in handle-free designs.
Innovation Solution
A dishwasher with a sensor device that generates a position signal compensated for movements in directions perpendicular to the primary actuation direction, using a coil and encoder bodies to detect the actuating element's position independently of vibrations and manufacturing tolerances, ensuring accurate detection of the operator's wish to open the door.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a sensor device is used to detect the operator's wish to open the door, then automatic door opening can be achieved, but the detection becomes susceptible to interference signals such as vibrations
Solution Approach 1:
The patent uses a differential measurement approach where two sensor devices measure the position of the actuating element from different dimensions or perspectives. By taking the difference between these two measurements, the system eliminates common-mode interference signals such as vibrations while preserving the genuine door opening signal.
Solution Approach 2:
The control device continuously monitors the position signal from the sensor devices and compares it against expected patterns for genuine door opening versus interference. This feedback mechanism allows the system to distinguish between actual user intent and spurious signals, maintaining reliable automatic operation despite environmental disturbances.
2Strength
If the door is designed to be opened with significant force, then the door structure remains robust, but operator comfort deteriorates
Solution Approach 1:
The patent introduces an actuating element as an intermediary mechanism between the door and the operator. This element amplifies small operator inputs and translates them into the larger forces needed to overcome the door's robust locking mechanism, making the door easy to open while maintaining its structural strength.
Solution Approach 2:
The patent replaces the direct mechanical force application with an automated electromagnetic actuation system. The control device triggers an opening drive that uses motorized or electromagnetic forces to open the door, eliminating the need for the operator to apply significant physical force while preserving the door's robust construction.
3Shape
If handle-free device fronts are implemented, then aesthetic appearance improves, but the ability to provide manual opening assistance deteriorates
Solution Approach 1:
The patent implements a self-service mechanism where the door system automatically detects and responds to opening requests without requiring manual handle operation. The sensor devices monitor the actuating element's position, and when a genuine opening request is detected, the control device automatically activates the opening drive to assist or complete the door opening action.
Solution Approach 2:
The patent replaces the traditional mechanical handle system with an automated sensor and actuation system. The handleless design incorporates sensors that detect user intent and trigger electromagnetic or motorized mechanisms to open the door, maintaining aesthetic appearance while providing automated opening assistance.
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 allows for reliable and interference-resistant automatic door opening and closing, enhancing user comfort and reducing the influence of external factors on the detection process.
Implementation Method 1
The at least one coil generates a magnetic field that varies over time, in which the encoder body moves
Implementation Method 2
Eddy currents are induced in the encoder body due to the magnetic field that changes over time, which in turn affect the coil, in particular determining its inductance
Implementation Method 3
This reaction on the coil depends on the distance between the sensor body and the coil. The position signal is then generated as a function of the feedback
Data Source
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AI summary
The present invention creates a household appliance (1), in particular a dishwasher, with a body (4), a door (3), an actuating element (12), which is activated by applying a compressive force (36) from the outside to the door (3) in a first direction (y) towards the body (4) and a sensor device (35) which is set up to transmit a position signal to indicate a position of the actuating element (12) relative to the body (4) in the first direction (y) to generate, which is compensated with respect to a position of the actuating element (12) relative to the body (4) in at least a second direction (z) perpendicular to the first direction (y).