Electric Cycle Torque Control via Resistance Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional electric bicycle propulsion power control systems do not account for resistance factors such as wind, hills, and load, and use a latency-prone feed-forward control scheme, requiring riders to exert force before power assistance is provided.

Innovation Solution

An assistance system with a resistance detecting unit, database, torque calculation unit, and torque-control handlebar grip that calculates and applies assist torque values based on resistance factors and user input to optimize torque delivery to the torque motor, using a feed-forward control scheme to provide power assistance proactively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional feed-forward control scheme is used where rider must exert force before power-assist force is involved, then the system structure is simple, but the response latency increases

Engineering Contradiction:

Improvecontrol system structureVSAvoidresponse latency

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The resistance detecting unit proactively detects resistance factors (wind, hills, load) before the rider pedals, and the controller pre-calculates and stores torque values in a database based on detected resistance. This preliminary action eliminates response latency by having assistance ready before the rider exerts force.

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If conventional power assist ratio control is used without considering resistance factors, then the control system is simple, but the riding efficiency deteriorates under resistance conditions

Engineering Contradiction:

Improvepower control systemVSAvoidriding efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The system proactively detects resistance factors (wind resistance, road gradient, load weight) before riding begins and pre-calculates torque values stored in the database. This allows the system to compensate for resistance factors in advance, maintaining high riding efficiency without complex real-time control adjustments.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system creates a database of torque values that copies and stores pre-calculated assistance torque for various resistance conditions. Instead of performing complex real-time calculations, the controller retrieves appropriate torque values from the database based on detected resistance, simplifying the control system while maintaining efficiency.

Inventive Principle:

Principle #26Copying

3Speed

If torque values are pre-calculated and stored in database for different resistance factors, then the response speed increases, but the device complexity increases

Engineering Contradiction:

Improveresponse speedVSAvoidsystem structure

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The system performs torque calculation in advance and stores results in a database structured by resistance factors (wind, gradient, load). This preliminary calculation approach achieves fast response by retrieving pre-computed values rather than calculating in real-time, while the database structure keeps complexity manageable.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses a database to store copied torque values for different resistance scenarios. This allows rapid retrieval of appropriate torque without complex real-time computation, achieving fast response while managing device complexity through structured data storage rather than complex algorithms.

Inventive Principle:

Principle #26Copying

4Measurement precision

If resistance detecting unit and database are added to the system, then the riding assistance accuracy improves, but the manufacturing cost increases

Engineering Contradiction:

Improveresistance detection accuracyVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The resistance detecting unit detects factors like wind resistance, road gradient, and load weight before riding begins. The controller uses these detections to retrieve pre-calculated torque values from the database, providing accurate resistance compensation without requiring expensive complex real-time control systems.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses a database to store torque values for different resistance conditions, allowing accurate assistance by retrieving appropriate pre-calculated values rather than requiring complex real-time computation hardware, thus improving accuracy while controlling manufacturing cost.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS10988206B1Assistance system for facilitating operation of electric cycle

Publication Date: 2021.04.27 YANGDING TIANJIN COMMERCE & TRADE CO LTD

AI summary

An assistance system includes a resistance detecting unit obtaining a resistance factor, a database storing starting torque values and operating torque values, a torque calculation unit including a controller, and a torque-control handlebar grip operated to trigger an assigned gain and to tune the same to be provided to the torque calculation unit. When switched to an aided mode, the controller calculates a compensated torque value based on one of the starting/operating torque values and the resistance factor, calculates an output torque value by a product of the compensated torque value, the assist ratio and the assigned gain, and controls a torque motor to drive rotation of a driving wheel based on the output torque value.