Regenerative Braking Controller for Electric Vehicles
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Solution Overview
Problem
In electric vehicles with regenerative braking systems, kinetic energy is not recovered when the driver presses the brake pedal, leading to increased burden on service brakes and reduced energy efficiency.
Innovation Solution
The system includes a controller that transitions the electric motor into a regenerative braking mode when the accelerator pedal is released, generating a first regenerative braking force, and further increases this force by an additional braking force when the brake pedal is pressed, allowing for kinetic energy recovery and reduced service brake burden.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If regenerative braking is not initiated during brake pedal operation, then service brakes can perform braking function, but kinetic energy cannot be recovered and burden on service brakes increases
Solution Approach 1:
The patent combines regenerative braking and service braking functions into a unified braking system. The controller integrates the motor generator's regenerative braking capability with the service brake system, allowing both functions to operate simultaneously or in coordination during brake pedal operation, thereby recovering kinetic energy while maintaining adequate braking performance.
Solution Approach 2:
The motor generator serves multiple functions: it acts as a drive motor during acceleration and as a regenerative braking device during deceleration and brake pedal operation. The service brake system also provides dual functionality by working independently or in conjunction with regenerative braking, ensuring braking capability across all operating conditions.
2Productivity
If regenerative braking force is increased during brake operation, then more kinetic energy can be recovered and service brake burden reduced, but braking force control complexity increases
Solution Approach 1:
The controller continuously monitors brake pedal operation status, vehicle speed, and braking force requirements, then dynamically adjusts the regenerative braking force accordingly. This feedback mechanism ensures optimal energy recovery while maintaining smooth and natural braking characteristics, preventing excessive regenerative braking that could cause vehicle instability or discomfort.
Solution Approach 2:
The regenerative braking force is dynamically adjusted based on real-time operating conditions including brake pedal displacement, vehicle speed, and driver braking intent. The system transitions smoothly between different braking modes (regenerative only, combined braking, or service brake only) to optimize both energy recovery and braking performance across varying conditions.
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
This configuration enhances energy recovery during braking, reduces the load on service brakes, and provides a natural braking feel by increasing the regenerative braking force in response to brake pedal operation, thereby improving energy efficiency and reducing brake capacity needs.
Implementation Method 1
the motor generates a braking force to be applied to the wheels, and operates as an electric generator to charge a battery. This operation is generally referred to as regenerative braking, in which kinetic energy of the vehicle is converted into electric energy.
Data Source
AI summary
An electric vehicle is provided. The electric vehicle may include a motor for driving a wheel; a brake device for braking the wheel in response to a driver's operation of a brake operation member; and a controller for controlling the motor in response to the driver's operation of an accelerator operation member. The controller may include a first motor control section for causing the motor to be placed in a regenerative braking mode to generate a first regenerative braking force, when a displacement amount of the accelerator operation member decreases to an amount less than a predetermined reference displacement amount; and a second motor control section for causing the motor to generate a second regenerative braking force which is a sum of the first regenerative braking force and a predetermined additional braking force, in response to the operation of the brake operation member.