Electromechanical Brake Control Without a Force Sensor
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Solution Overview
Problem
Existing electromechanical brakes face issues with stability and precision due to thermal expansion of components, leading to errors in braking force measurement using position sensors, and increased complexity and cost with force sensors.
Innovation Solution
An electromechanical brake system that utilizes a position sensor and current sensor to determine a limit current value based on piston position, compensating for thermal expansion and environmental factors, allowing precise braking force control without a force sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a force sensor is mounted to measure braking force, then measurement precision is improved, but device complexity increases and manufacturing cost increases
Solution Approach 1:
The patent extracts the force sensor from the brake system and replaces it with a sensorless control method that uses the existing position sensor and motor current data to estimate braking force, thereby simplifying the device structure while maintaining measurement capability
Solution Approach 2:
The patent replaces the mechanical force sensor with an electronic estimation system that calculates braking force based on motor current and position data, substituting a complex mechanical measurement device with a simpler computational approach
2Measurement precision
If a force sensor is mounted to measure braking force, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent removes the force sensor from the system, eliminating its associated manufacturing costs while maintaining the ability to measure braking force through alternative means using existing sensors
Solution Approach 2:
The patent uses inexpensive existing sensors (position sensor and current sensor) that are already part of the motor control system, replacing the expensive force sensor with cheaper, readily available components
3Device complexity
If position sensor is used to measure braking force, then device complexity is reduced, but measurement precision deteriorates due to thermal expansion
Solution Approach 1:
The patent implements a feedback mechanism where motor current data is continuously monitored and used to compensate for thermal expansion effects, allowing the system to maintain measurement precision despite temperature changes by dynamically adjusting based on real-time conditions
Solution Approach 2:
The patent changes the measurement parameter from direct position to a combination of current and position, using motor current as an additional parameter that remains stable despite thermal expansion, thereby maintaining measurement accuracy 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
The system reduces errors in braking force measurement, simplifies design, reduces size, and lowers manufacturing costs while maintaining precise control over braking forces.
Implementation Method 1
a motor for generating driving force
Implementation Method 2
a brake pad connected to the piston; a wheel disk configured to come into contact with the brake pad to generate a braking force
Data Source
AI summary
According to at least one embodiment, the present disclosure provides an electromechanical brake comprising: a motor for generating driving force; a piston coupled to the motor and configured to be movable; a brake pad connected to the piston; a wheel disk configured to come into contact with the brake pad to generate a braking force; a sensor unit including a position sensor for measuring a position of the piston and a current sensor for measuring a current value flowing through the motor; and a control unit (ECU: Electronic Control Unit) which determines a limit current value of the motor according to the position of the piston, generates a braking force based on the position sensor within the limit current value, and generates a braking force based on the current sensor when out of the limit current value.