Mobile robots with intelligent capacitive touch sensing

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Solution Overview

Problem

Mobile robots with capacitive user interfaces are susceptible to detecting unintended inputs from environmental factors like large conductors or wet surfaces, leading to spurious activation and potential operational disruptions during navigation.

Innovation Solution

The implementation of a mobile robot system with recessed capacitive sensors and a controller that selectively disregards inputs based on the robot's operating status, using mobility sensors to differentiate between intended and unintended inputs by adjusting detection thresholds and recognizing input characteristics such as duration and capacitance changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If capacitive sensors are used for user interface input detection, then user interaction capability is improved, but sensitivity to unintended inputs from environmental factors increases

Engineering Contradiction:
Improveuser interaction capabilityVSAvoidinput detection accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system dynamically adjusts the capacitance threshold for detecting user inputs based on the robot's operating status. When the robot is stationary, a lower threshold is used to detect light touches. When the robot is moving or performing cleaning operations, a higher threshold is applied to ignore environmental interference while still detecting deliberate user inputs.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The detection parameters (capacitance threshold values) are changed based on the robot's operational state. The controller selectively disregards inputs that fall below the dynamically adjusted threshold, effectively filtering out spurious signals from environmental factors like large conductors or wet surfaces while maintaining sensitivity to genuine user interactions.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the robot increases sensitivity to detect light touches, then user input detection is improved, but false activation from environmental factors increases

Engineering Contradiction:
Improvetouch detection sensitivityVSAvoidfalse activation from environmental factors
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The system employs dynamic threshold adjustment where the capacitance detection threshold is not fixed but varies according to the robot's operational context. This allows the system to maintain high measurement precision for touch detection when needed while automatically reducing sensitivity to prevent false activation during movement or cleaning operations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The controller continuously monitors the robot's operational status and uses this feedback to adjust the input detection threshold in real-time. This feedback mechanism ensures that the sensitivity level is always appropriate for the current operating conditions, preventing false activation while maintaining accurate touch detection capability.

Inventive Principle:
Principle #23Feedback

3Reliability

If the robot disregards inputs during operation, then operational stability is improved, but user control during navigation is reduced

Engineering Contradiction:
Improveoperational stabilityVSAvoiduser control responsiveness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system dynamically switches between two operational modes: during navigation and cleaning operations, it disregards capacitive inputs to maintain operational stability; when stationary and idle, it becomes fully responsive to user inputs. This dynamic behavior ensures that the robot remains controllable when the user needs to interact with it while preventing unintended activation during autonomous operation.

Inventive Principle:
Principle #15Dynamics

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

This approach reduces the detection of unintended inputs, ensuring more precise and reliable user interaction during navigation and mission execution, thereby enhancing the operational stability of mobile robots.

Implementation Method 1

A typical capacitive sensor (also referred to herein as a capacitive touch pad, or touchpad) includes a conductor separated from the user by a thin insulator. The conductor is connected to a sensing device with a conductive trace. The touchpad can define a capacitor relative to other conductors in its vicinity.

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

as a user's finger is inserted into the space through which electric field lines flow between the touchpad and the ground plane of the sensing device (e.g., above the touchpad), the capacitance (Cf) may increase due to the dielectric effect

Methodology Applied
Scientific EffectDielectric effect: Dielectric

Data Source

PatentEP3846668B1Mobile robots with intelligent capacitive touch sensing
Publication Date: 2023.09.13 IROBOT CORP
  • EP3846668B1 patent drawingFigure 1
  • EP3846668B1 patent drawingFigure 2
  • EP3846668B1 patent drawingFigure 3A~3B

AI summary

A mobile robot includes a recessed well in a top surface of the mobile robot, at least one capacitive sensor underlying the recessed well and having a first region and a second region, one or more mobility sensors, and a controller coupled to the at least one capacitive sensor and the one or more mobility sensors. The controller is configured to determine an operating status of the mobile robot responsive to output signals from the one or more mobility sensors, and selectively disregard an input at a first portion of the recessed well corresponding to the first region of the at least one capacitive sensor based on the operating status of the mobile robot.