Vertical Robot Drift Correction via Magnetic Feedback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The United States faces challenges in education, particularly in STEM fields, with a significant number of students not being proficient in mathematics and science, and a shortage of students pursuing STEM majors, which may lead to a deficit of 3 million high-skill workers by 2018.

Innovation Solution

A mobile robot designed to navigate on vertically mounted whiteboards or ferromagnetic surfaces, equipped with magnets, sensors, and a computing device, allowing for interactive marking and programming, is proposed to create engaging learning experiences and inspire students to pursue STEM studies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a mobile robot is designed to navigate on vertical surfaces using magnets and wheels, then the robot can provide engaging educational experiences for students, but the robot experiences drive slippage drift due to gravity acting on the wheels

Engineering Contradiction:
Improverobot's ability to navigate vertical surfacesVSAvoiddrive accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The robot incorporates magnetic force sensors that continuously measure the magnetic force between the magnets and the vertical surface. This feedback is fed to the computing device, which calculates drift corrections based on the measured magnetic force and gravity vector, then adjusts the wheel motor commands to compensate for drift and maintain accurate trajectory following.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces purely mechanical drive control with a hybrid system that uses magnetic field measurements and computational algorithms. Instead of relying solely on mechanical wheel-surface interaction, the system substitutes magnetic force sensing and software-based drift correction to achieve more reliable positioning on vertical surfaces.

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

2Ease of operation

If the robot uses magnets to constrain movement parallel to the vertical surface, then the robot can be held to the surface for marking, but magnetic force variations cause drift that affects drawing precision

Engineering Contradiction:
Improverobot's ability to be held to surfaceVSAvoiddrawing accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

Magnetic force sensors provide continuous feedback on the magnetic attraction between the robot's magnets and the vertical surface. The computing device uses this feedback to detect variations in magnetic force and calculates corresponding drift corrections, adjusting the robot's trajectory in real-time to maintain drawing accuracy despite magnetic force fluctuations.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes operational parameters (motor commands, wheel speeds) based on real-time measurements of magnetic force and gravity vector. By adjusting these parameters in response to measured conditions, the robot compensates for drift and maintains precise drawing accuracy across varying magnetic environments.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the robot incorporates sensors and computing devices for drift correction, then navigation accuracy improves, but the device complexity increases

Engineering Contradiction:
Improveposition measurement accuracyVSAvoidrobot system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The computing device performs multiple functions: it processes data from magnetic force sensors, calculates drift corrections based on gravity vector measurements, generates corrected trajectory commands, and controls the wheel motors. By consolidating these diverse functions into a single computing device, the system achieves high measurement precision without proportionally increasing overall system complexity.

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

Solution Approach 2:

The magnetic force sensors act as intermediaries between the physical magnetic field environment and the computing device's control algorithms. These sensors translate physical magnetic force variations into electrical signals that the computing device can process, enabling accurate drift detection and correction without requiring direct mechanical measurement of drift.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 robot provides a unique and stimulating educational tool that can help teach problem-solving, logic, and programming skills, potentially increasing student interest and proficiency in STEM fields, while being versatile enough for classroom and home use.

Implementation Method 1

at least one magnet in or coupled with the robot body constraining the robot to move parallel to a vertical, magnetically responsive surface

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 2

a magnetic force sensor configured to measure a magnetic field generated by the at least one magnet of the robot and the vertical, magnetically responsive surface

Methodology Applied
Scientific EffectMagnetic field measurement: Magnetometer

Implementation Method 3

an accelerometer measuring a gravity vector having a magnitude and a direction

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP3445534B1Magnetic receptive sensor and optimized drawing and erasing for vertically driving robot
Publication Date: 2020.12.02 PRESIDENT & FELLOWS OF HARVARD COLLEGE
  • EP3445534B1 patent drawingFigure 1~2
  • EP3445534B1 patent drawingFigure 3~4
  • EP3445534B1 patent drawingFigure 5~6

AI summary

A vertically driving marking robot includes a robot body; at least one magnet constraining the robot to move parallel to a vertical, magnetically responsive surface; a drive configured to displace the robot relative to the surface while the robot is held to the surface; a holder configured to hold a marker; an accelerometer measuring a gravity vector; a computing device in communication with the optical sensors, the accelerometer, and the drive. The computing device includes a processor and computer-readable memory, wherein the computer-readable memory includes non-transitory program code for at least one of the following actions: (a) generating a drift correction to compensate for drive slippage drift in response to and as a function of the gravity vector and (b) commanding the drive to displace the robot along a desired trajectory in response to the drift correction.