Electromechanical Brake Control Using Motor Angle Instead of Force Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electromechanical brakes require force sensors to measure brake pressure, which are space-consuming and expensive, and the initial release clearance between friction elements needs to be accurately set to ensure precise braking force, but this setup is costly and inefficient.
Innovation Solution
A method to operate a force-sensor-less electromechanical service brake by determining the braking contact point and force-displacement characteristic using the total rotation angle of the electric motor shaft, eliminating the need for force sensors and allowing precise control of braking force through stored profiles and current values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If force sensors are used to measure brake pressure, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the force measurement function from a dedicated force sensor and relocates it to the electric motor itself. The motor's current consumption serves as the measurement parameter, eliminating the need for separate force sensors in the brake caliper assembly.
Solution Approach 2:
The patent introduces the electric motor as an intermediary element that performs both actuation and measurement functions. The motor's electrical characteristics (current, power consumption) serve as an indirect but accurate proxy for brake pressure, replacing direct mechanical force sensing.
2Manufacturing precision
If force sensors are installed in the brake system, then braking force accuracy is improved, but manufacturing cost increases
Solution Approach 1:
The electric motor is designed to perform multiple functions: it acts as both the actuator that generates braking force and the sensor that measures brake pressure. This multi-functionality eliminates the need for separate force sensing components, reducing overall system cost while maintaining measurement accuracy.
Solution Approach 2:
The brake system uses its own actuator (the electric motor) to perform the measurement function. The motor's current consumption automatically provides information about the applied braking force, making the system self-measuring without requiring external sensing components.
3Reliability
If the release clearance is accurately set using force sensors, then braking performance is improved, but initial setup complexity increases
Solution Approach 1:
The system uses feedback from the motor's current consumption during the closing process to automatically determine the optimal release clearance. The control unit monitors current values and identifies the braking contact point, automatically adjusting the clearance setting without requiring manual intervention or complex setup procedures.
Solution Approach 2:
The patent replaces mechanical measurement methods (force sensors, manual gauges) with an electrical measurement approach. The motor's current profile serves as the measurement signal, and the control unit processes this electrical data to automatically set the release clearance, simplifying the setup process.
4Measurement precision
If regular detection of brake parameters is performed, then braking force accuracy is maintained, but measurement system complexity increases
Solution Approach 1:
The electric motor continuously provides measurement data through its current consumption during operation. Every actuation cycle generates new measurement information about brake pressure and friction element position, enabling continuous monitoring without requiring separate detection systems or interrupting normal brake function.
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 reliable braking without force sensors, reducing costs and complexity while maintaining accurate braking performance by using the total rotation angle as a measurable parameter to determine the braking contact point and force-displacement characteristics.
Implementation Method 1
an element moved by an electric motor, for example a ball screw, is provided, which acts on movable friction elements of the brake
Implementation Method 2
a ball screw, is provided, which acts on movable friction elements of the brake
Implementation Method 3
a brake pad is pressed against a brake disk and in this way the brake pressure required to close the brake is generated
Data Source
AI summary
In a method for operating a force-sensor-less electromechanical service brake in a brake system of a vehicle, a current value of a braking contact point and a current profile of a force-displacement characteristic of the electromechanical service brake are determined as a function of the total rotation angle of a shaft of an electric motor of the electromechanical service brake. These values are determined in regular driving operation of the vehicle. In the case of a braking request, the electric motor is activated in accordance with the current value of the braking contact point and the current profile of the force-displacement characteristic in order to satisfy the braking request. The electric motor has a detection element, which detects the total rotation angle of the shaft and a rotation rate of the electric motor.