Brake Booster Motor Dynamic Braking During Power Loss
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Solution Overview
Problem
Modern power-assisted braking systems in vehicles face the risk of damage due to sudden power loss, particularly when the brake booster subsystem loses power, leading to rapid movement of components that can cause fractures or damage.
Innovation Solution
A method and system that utilize a bridge switching circuit and a power supply section to generate a DC voltage from an AC voltage produced by the motor during power loss, allowing for dynamic braking of the motor without requiring additional software or modifications to the electronic control unit (ECU) or bridge switching circuit, thereby preventing damage to the brake booster subsystem.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the brake booster subsystem loses power during operation, then the piston is rapidly driven back to its retracted position, but this causes significant force to be exerted on the housing interior wall which may fracture the housing or damage the ballscrew
Solution Approach 1:
The patent applies preliminary anti-action by detecting power loss conditions before the piston completes its rapid retraction, and activating the dynamic braking mechanism to apply counter-force that opposes the harmful reverse rotation of the motor. This prevents the ballscrew from being driven with excessive force and striking the housing interior wall, thereby preventing fractures and damage before they occur.
Solution Approach 2:
The patent converts the harmful effect of the motor's reverse rotation during power loss into a beneficial braking action. By detecting the power loss condition and controlling the bridge switching circuit to act as a dynamic brake, the system utilizes the motor's electromagnetic properties to create resistance that slows and stops the reverse rotation, transforming what would be a damaging force into a protective braking mechanism.
2Reliability
If additional hardware or software modifications are made to detect power loss and implement dynamic braking, then damage prevention capability is improved, but device complexity increases
Solution Approach 1:
The patent applies self-service by utilizing existing components within the brake booster subsystem to perform the detection and braking functions. The bridge switching circuit, which already exists for motor control, is repurposed to detect power loss conditions and simultaneously serve as a dynamic brake. This eliminates the need for separate detection circuits, sensors, or control units, as the existing infrastructure performs multiple functions including damage prevention.
Solution Approach 2:
The patent implements multi-functionality by enabling the bridge switching circuit to perform its original motor control function while also serving as a power loss detector and dynamic brake. This single component handles multiple tasks that would traditionally require separate systems, thereby improving reliability without increasing device complexity.
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 real-time detection and prevention of damage to the brake booster subsystem by dynamically braking the motor during power loss events, ensuring the system's integrity and safety without additional hardware or software modifications.
Implementation Method 1
A method and system that utilize a bridge switching circuit and a power supply section to generate a DC voltage from an AC voltage produced by the motor during power loss
Data Source
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AI summary
A method is disclosed for controlling operation of a motor-driven brake boost assist system of a vehicle braking system during a loss of battery power to the brake boost assist system. The method may involve detecting a condition during which a power loss event to the brake boost assist system has occurred, and a motor associated with the brake boost assist system is being driven by linear movement of a component within the brake boost assist system in response to fluid pressure developed within the brake boost assist system. The method further involves using a voltage generated by the motor during the power loss event to help initiate a dynamic braking action on the motor.