Hybrid Bicycle Generator Torque Control for Rider Power Correlation
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Solution Overview
Problem
Series hybrid bicycles fail to accurately correlate drive power at the wheel with muscle power applied by the rider, especially in extreme situations, due to limitations in generator torque and rotational speed, leading to inadequate propulsion.
Innovation Solution
A hybrid bicycle system with a control device that determines two types of rider power, one from generator torque and another from pedal rotational speed, allowing the drive motor to adjust power output based on total rider power, using a microprocessor to manage energy distribution between the battery, generator, and drive motor, and incorporating sensors for pedal and drive wheel rotational speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the generator torque is increased to capture extreme rider power, then the generator torque exceeds its maximum capacity, but the pedal rotational speed increases uncontrollably and the correlation between drive power and rider power breaks down
Solution Approach 1:
The control device dynamically adjusts the generator torque based on real-time pedal rotational speed measurements. When pedal speed exceeds a threshold indicating extreme rider power, the system transitions from using only generator torque to combining generator torque with direct drive motor power, maintaining accurate power correlation across all riding conditions
Solution Approach 2:
The control device acts as an intermediary that receives inputs from both the generator torque sensor and pedal rotational speed sensor, processes this information, and coordinates the drive motor output to accurately reflect total rider power intent, even when generator torque alone is insufficient
2Power
If the drive motor power is increased to match extreme rider power, then the drive power correlates accurately with rider power, but the energy consumption from the battery increases
Solution Approach 1:
The system applies drive motor power selectively and proportionally based on the degree of extreme rider power detected. Instead of always providing full power assistance, the drive motor supplements only the portion of power needed to maintain accurate correlation when generator torque is insufficient, reducing unnecessary battery energy consumption
Solution Approach 2:
The control device continuously monitors and adjusts the drive motor power output based on changing riding conditions, transitioning between different power delivery modes to match rider intent while optimizing battery energy usage across varying power demands
3Measurement precision
If the control system complexity is increased to accurately determine and respond to extreme rider power, then the correlation between drive power and rider power is maintained, but the device complexity increases
Solution Approach 1:
The control device is designed to perform multiple functions: it processes generator torque data, measures pedal rotational speed, determines rider power intent, and controls drive motor output. This multi-functional approach consolidates complexity into a single integrated unit rather than requiring separate systems for each function
Solution Approach 2:
The system implements a feedback loop where the control device continuously monitors pedal rotational speed and generator torque, compares the measured power against the desired power correlation, and adjusts drive motor output in real-time to maintain accurate rider power representation
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
Enables precise control of drive power to match rider input even in extreme situations, ensuring efficient propulsion and energy management, particularly by accounting for increased pedal speed and torque beyond maximum generator capacity.
Implementation Method 1
The hybrid bicycle comprises a generator whose torque can be set by means of a control device and dependent upon construction is limited to a maximum generator torque
Implementation Method 2
a drive motor that is connected to a drive wheel of the bicycle so as to drive the drive wheel, and also a battery for supplying the drive motor
Data Source
AI summary
The invention relates to a hybrid bicycle that is driven by muscle power and electrical energy, in particular a series hybrid bicycle comprising a generator whose torque can be set by a control device and dependent upon the construction is limited to a maximum generator torque, and also pedals that are connected to the generator so as to apply a pedal torque to the generator by a rider so as to drive the generator, and also a drive motor that is connected to a drive wheel of the bicycle so as to drive the drive wheel, and also a battery for supplying the drive motor.