Electric Bicycle Speed Signal Manipulation Detection

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Solution Overview

Problem

Existing electric bicycles face challenges in reliably and cost-effectively detecting manipulated speed signals from sensors, which can lead to improper regulation of the traction motor, potentially causing safety issues and legal compliance problems.

Innovation Solution

An electric bicycle equipped with a manipulation detection unit that compares actual total drive power with a calculated target drive power, using sensors for motor speed, torque, and environmental factors to identify deviations and detect signal manipulation, allowing for simple and cost-effective intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a second sensor is added to detect speed signal manipulation, then detection reliability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvedetection reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses existing sensors (acceleration sensor, torque sensor, speed sensor) to detect manipulation. The manipulation detection unit analyzes data from these existing components without requiring additional sensors, making the system self-sufficient and avoiding increased complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system continuously monitors the relationship between acceleration, torque, and speed signals, comparing actual values with expected values based on physical laws. This feedback mechanism enables reliable detection of manipulations while using only existing sensors

Inventive Principle:
Principle #23Feedback

2Measurement precision

If transmission ratio and gear shift considerations are included in speed calculation, then measurement precision is improved, but device complexity and calculation complexity increase

Engineering Contradiction:
Improvespeed measurement precisionVSAvoidcalculation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system leverages existing data from the controller about transmission ratio and gear shift position. Rather than adding new sensors or complex mechanical systems, it uses information already available in the control unit to achieve precise speed measurement

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The manipulation detection unit serves multiple functions: it calculates actual speed using transmission ratio data, detects signal manipulation, and validates sensor readings. This multi-functionality achieves precise measurement without increasing device complexity

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

3Reliability

If manipulation detection is continuously performed, then detection reliability is improved, but energy consumption increases

Engineering Contradiction:
Improvedetection reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The manipulation detection unit performs detection at specific intervals or under specific conditions (e.g., when certain thresholds are exceeded) rather than continuously. This periodic approach maintains detection reliability while significantly reducing energy consumption compared to continuous monitoring

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system focuses detection efforts on critical moments or conditions where manipulation is most likely to occur, performing full analysis only when necessary. This partial action approach maintains reliability for detecting actual manipulations while minimizing unnecessary energy expenditure

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4032795A1Detection of sensor manipulation of an electric bicycle
Publication Date: 2022.07.27 SRAM LLC
  • EP4032795A1 patent drawingFigure 1
  • EP4032795A1 patent drawingFigure 2
  • EP4032795A1 patent drawing

AI summary

The invention relates to an electric bicycle with a front wheel (24), a rear wheel (22), an electric traction motor (30) which drives the front wheel (24) or the rear wheel (22), a traction accumulator (34) for supplying the traction motor (30) with electrical energy, an electric bicycle speed sensor (82) for determining the current electric bicycle speed, an electric bicycle controller (50) for controlling the traction motor (30), wherein the electric bicycle controller (50) regulates the traction motor (30) at a maximum electric bicycle speed, and a tamper detection unit (54) for detecting manipulation of an electric bicycle speed signal from the electric bicycle speed sensor (82).wherein the manipulation detection unit (54) compares an actual total drive power generated by the traction motor (30) and/or by a rider with a target drive power calculated from the electric bicycle speed and detects manipulation of the electric bicycle speed signal if the target drive power deviates from the actual total drive power.