Brake Booster Negative Pressure Prediction Using Pedal Force
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Solution Overview
Problem
The existing methods for controlling the operation of a vehicle's air conditioner based on the negative pressure of the intake manifold instead of a real brake booster sensor lead to frequent shutdowns, affecting cooling and braking performance, as they inaccurately determine the sufficiency of the brake booster pressure.
Innovation Solution
A system and method that predict the brake booster's negative pressure by integrating the charging and discharging rates with the brake pedal force, using a controller to calculate and adjust the predicted pressure over time, thereby improving the accuracy and reducing the frequency of air conditioner shutdowns without requiring additional hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the negative pressure of the intake manifold is used to control the air conditioner operation, then the cost is reduced by omitting the booster sensor, but the cooling performance deteriorates due to frequent air conditioner shutdowns
Solution Approach 1:
The patent creates a virtual brake booster sensor by copying the function of the real sensor through software calculation. The controller calculates the negative pressure of the brake booster by integrating the charging rate and discharging rate based on intake manifold pressure and brake pedal force, providing a virtual measurement signal that replaces the need for physical hardware sensor
Solution Approach 2:
The patent replaces the mechanical measurement system (physical brake booster sensor) with a computational model. The controller uses mathematical integration of charging and discharging rates to substitute the mechanical sensing function, eliminating hardware while maintaining measurement capability
2Ease of manufacture
If the reference pressure for stopping the air conditioner is raised using the negative pressure of the intake manifold, then the manufacturing cost is reduced, but the braking performance deteriorates due to insufficient pressure detection
Solution Approach 1:
The patent creates a virtual brake booster sensor by copying the function of the real sensor through software calculation. The controller calculates the negative pressure of the brake booster by integrating the charging rate and discharging rate based on intake manifold pressure and brake pedal force, providing a virtual measurement signal that replaces the need for physical hardware sensor
Solution Approach 2:
The patent implements feedback control by continuously monitoring the calculated negative pressure of the brake booster and using this information to control air conditioner operation. The controller adjusts the air conditioner based on the integrated pressure values, creating a closed-loop system that responds to actual braking conditions
Data Source
AI summary
A system for predicting a negative pressure of a brake booster of a vehicle includes: a driving information detector configured to detect driving information according to driving of the vehicle; and a controller configured to calculate a negative pressure of an intake manifold based on a pressure of the intake manifold and an atmospheric pressure that is the driving information and including a booster negative pressure predictor configured to predict the negative pressure of the brake booster by integrating over time a change rate according to a charging rate and a discharging rate of the negative pressure calculated using a previous negative pressure of the brake booster calculated in a previous cycle according to a logic for predicting the negative pressure of the brake booster and the negative pressure of the intake manifold and a brake pedal force of a current cycle.