Multi-Stage Brake Booster Deactivation for Comfortable Emergency Braking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing emergency braking systems in vehicles lack a comfortable and safe method to terminate brake boosting during emergency braking processes, often relying on pressure sensors and abrupt changes in braking force, which can be inefficient and unpredictable.
Innovation Solution
A method utilizing vehicle state variables, such as wheel speed data, to evaluate and manage the activation and deactivation of the brake booster in multiple stages, allowing for a gradual reduction of braking force based on predefined threshold values and activation periods, without relying on pressure sensors, ensuring a controlled transition from emergency to normal braking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the brake booster is switched off abruptly when emergency braking ends, then the braking force returns quickly to normal levels, but this causes uncomfortable and unpredictable braking behavior for the driver
Solution Approach 1:
The brake booster deactivation process is divided into multiple stages: a first stage where the brake booster is reduced to a lower value when a first state variable limit value is reached, and a second stage where it is reduced to zero when a second state variable limit value is reached. This segmented approach allows for a more comfortable and controlled transition from emergency braking to normal braking.
Solution Approach 2:
The invention introduces dynamic adaptation by making the activation period depend on vehicle speed and other state variables. The system adapts the brake booster deactivation timing and rate based on current driving conditions, ensuring optimal comfort and safety for varying situations rather than using a fixed deactivation protocol.
2Measurement precision
If pressure sensors are used to determine when to reduce brake boosting, then the system can accurately monitor brake pressure, but this increases device complexity and cost
Solution Approach 1:
The invention uses wheel speed sensor data as an intermediary to indirectly determine brake pressure conditions. Instead of directly measuring brake pressure with pressure sensors, the system evaluates wheel speed changes and other state variables to infer the appropriate timing for brake booster deactivation, achieving accurate control without additional pressure sensing hardware.
Solution Approach 2:
The system utilizes existing sensor data (wheel speed sensors already present in the vehicle) to self-determine the appropriate moments for brake booster deactivation. The evaluation unit processes available vehicle state information to autonomously decide when to reduce or eliminate brake boosting, eliminating the need for dedicated pressure sensors.
3Ease of operation
If the brake booster activation period is fixed regardless of vehicle speed, then the system is simple to control, but it cannot adapt to different driving situations and reduces safety
Solution Approach 1:
The activation period is made dynamic by making it dependent on vehicle speed and other state variables. The system automatically adjusts the duration and characteristics of brake booster activation based on current driving conditions, ensuring safe and appropriate emergency braking assistance whether the vehicle is traveling at low or high speeds.
Solution Approach 2:
The invention changes the parameter of activation period from a fixed value to a variable that depends on vehicle speed and state variables. This allows the system to adapt its behavior to different driving situations, improving safety by ensuring the brake booster remains active long enough to be effective at various speeds while automatically deactivating when appropriate.
Data Source
AI summary
In a method for carrying out an emergency braking operation by means of a break assist system in a vehicle, a brake actuation predefined by the driver is boosted, wherein the braking force boost is switched off in at least two stages.