Electric Parking Brake Braking Force Estimation
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Solution Overview
Problem
Existing electric parking-braking systems face challenges in accurately determining the minimum braking force between the pad and brake disc, leading to high dispersion and excessive stress on the system, which increases costs and dimensions.
Innovation Solution
A method that estimates the braking force by detecting instantaneous electric current and voltage, using a data processing unit to compare these values with a reference, allowing for accurate and timely intervention without the need for force sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If force sensors are used to directly detect braking force, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent introduces an intermediary estimation method that uses easily measurable electrical parameters (current, voltage, time) as mediators to infer braking force indirectly. Instead of directly measuring force with complex sensors, the system measures electrical quantities and uses a data processing unit to estimate the braking force based on the relationship between electrical consumption and mechanical work, thereby resolving the contradiction between measurement precision and device complexity
Solution Approach 2:
The patent replaces the mechanical force sensing system with an electrical measurement and calculation system. By substituting direct mechanical force detection with electrical parameter measurement and computational estimation, the system achieves comparable measurement precision while significantly reducing device complexity and cost
2Reliability
If reference current values are set high to guarantee minimum braking force, then reliability is improved, but system stress and dimensions increase
Solution Approach 1:
The patent implements a feedback mechanism where the data processing unit continuously monitors electrical parameters in real-time, estimates braking force, and compares it with the minimum required value. This closed-loop feedback allows the system to dynamically adjust and maintain reliable braking force without permanently oversizing components, as the system responds to actual conditions rather than assuming worst-case scenarios
Solution Approach 2:
The patent performs preliminary estimation of braking force during the parking brake application process by continuously calculating based on electrical parameters. This preliminary action allows the system to verify braking force adequacy in real-time and stop the motor as soon as the minimum force is achieved, preventing excessive stress accumulation that would result from using overly conservative fixed reference values
3Device complexity
If indirect braking force determination methods are used, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent changes the measurement parameters from direct mechanical force to electrical parameters (current, voltage, time) that are inherently more precise and easier to measure. By transforming the measurement domain from mechanical to electrical, the system achieves higher measurement precision while maintaining device simplicity, as electrical sensors provide more accurate and stable readings than mechanical force sensors would in this application
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 method provides high accuracy and reliability in estimating the braking force, reducing system stress and costs while maintaining safety and flexibility across varying conditions.
Implementation Method 1
an electric motor (6) operatively connected to said first piston (5) by means of an electromechanical mechanism (7) adapted to transform a rotary motion of said electric motor (6) into a linear motion of said first piston (5)
Implementation Method 2
The rotary motion of the electric motor is then converted by an electromechanical motion conversion gear mechanism into a linear motion of a piston
Data Source
AI summary
A method for estimating a braking force applicable between pad and brake disc by an electric parking-braking system of a vehicle is described. The method may include detecting, by one or more sensors of electric quantities of an electric motor, an electric current delivered to the electric motor and an instantaneous value of an electric voltage for electrically supplying the electric motor, during a parking-braking operation. The parking-braking operation may have a first non-contact stage between a first pair of pads of a first brake caliper and a first brake disc. The parking-braking operation may also have a second contact stage between the first pair of pads of the first brake caliper and the first brake disc.