Hybrid Vehicle Controller Preventing Battery Overcharge During Wheel Lock
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Solution Overview
Problem
In hybrid vehicles, existing control systems face challenges in preventing battery overcharging when wheel speed drops abruptly, leading to excessive electricity generation and potential damage to the battery, especially during direct power distribution control and traction control scenarios.
Innovation Solution
A control system that determines when a drive wheel is expected to be locked and reduces electric power generation by the generator to prevent overcharging, either by shifting operating modes or adjusting power output based on sensor inputs and assist control system activation, ensuring the battery is charged within acceptable limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the generator is driven to generate electricity during direct power distribution control, then the battery can be charged, but the battery may be overcharged when wheel speed drops abruptly
Solution Approach 1:
The control device predicts wheel lock occurrence before it actually happens by monitoring wheel acceleration and deceleration rates. When prediction indicates potential wheel lock, the control device proactively adjusts the generator output power to prevent overcharging, rather than waiting for the wheel lock to occur and then reacting.
Solution Approach 2:
The control device continuously monitors wheel speed, wheel acceleration, and battery charge/discharge status to dynamically adjust generator output. The system uses feedback from wheel speed sensors and battery state measurements to real-time control the generator power output, ensuring the battery is charged within safe limits while maximizing energy utilization.
2Stability of the object's composition
If the torque command to the drive motor is corrected by an increased time constant, then the wheel speed can be adjusted in a mild manner, but it takes longer time to adjust the actual wheel speed to the target speed
Solution Approach 1:
The control device dynamically adjusts the time constant based on real-time wheel conditions. When wheel slip is detected, the time constant is increased to provide mild adjustment. When wheel lock is predicted or actual wheel lock occurs, the time constant is reduced to enable faster response. This dynamic adjustment allows the system to optimize between stability and response speed according to current operating conditions.
Solution Approach 2:
The control device changes the time constant parameter adaptively based on wheel acceleration and deceleration rates. By modifying this control parameter in response to predicted wheel lock conditions, the system achieves both mild adjustment during normal operation and faster response when wheel lock is anticipated, resolving the contradiction between stability and adjustment time.
3Power
If the generator generates excessive electric power when wheel speed drops abruptly, then the drive motor can operate at higher power, but the surplus electricity accumulates in the battery causing overcharging
Solution Approach 1:
The control device predicts wheel lock before it occurs by detecting rapid wheel deceleration. When wheel lock is predicted, the control device proactively reduces generator output power to match the reduced power consumption of the drive motor, preventing electricity surplus accumulation that would lead to battery overcharging.
Solution Approach 2:
The control device uses feedback from wheel speed sensors and drive motor power consumption measurements to dynamically adjust generator output. When wheel speed drops abruptly indicating predicted wheel lock, the system reduces generator power output in real-time to match actual power consumption, preventing electricity accumulation and battery overcharging while maintaining optimal drive motor operation.
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
Prevents battery overcharging and limits damage by adjusting electric power generation in response to wheel lock conditions, maintaining optimal charging levels and power balance between the generator and drive motor.
Implementation Method 1
a generator that is driven by the engine
Implementation Method 2
a drive motor that is connected to drive wheels, and that is operated to generate a drive torque for propelling the hybrid vehicle by supplying the electric power to the drive motor
Data Source
AI summary
A control system for a hybrid vehicle that can prevent an overcharging of a battery even if a wheel speed drops abruptly. The hybrid vehicle comprises: an engine; a generator that is driven by the engine; a drive motor that generate a drive torque; and a battery. The electric power generated by the generator is supplied directly to the battery or the drive motor. A controller is configured to determine whether the drive wheel will be locked, and to reduce the electric power generated by the generator less than an acceptable input power to the battery if the drive wheel is expected to be locked.