Brake Assist Device Position Sensor Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current braking assistance devices for motor vehicles face issues with the robustness and maintenance of position sensors mounted on moving parts, requiring replacement of the entire servomotor when the sensor fails and experiencing wear due to frequent movement.
Innovation Solution
A Hall effect sensor with a fixed detector and a magnetic detection target driven by the moving assembly, allowing for absolute stroke measurement and angular indexing of the rotor, enabling the control unit to determine the position of the valve body and plunger, and facilitating easier assembly and disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the position sensor is mounted directly on the moving valve body, then the sensor can accurately detect the position of the moving assembly, but the sensor experiences wear and requires replacement of the entire servomotor when the sensor fails
Solution Approach 1:
The sensor system is segmented into two independent parts: a fixed detector mounted on the stationary housing and a magnetic target attached to the moving plunger. This segmentation allows the detector to remain stationary while still detecting the position of moving components, eliminating wear on the sensor itself and enabling independent replacement of the magnetic target if needed.
Solution Approach 2:
A magnetic field is introduced as an intermediary between the fixed detector and the moving plunger. The magnetic target on the plunger interacts with the fixed Hall effect detector through this magnetic field, allowing position detection without direct mechanical contact between the sensor and moving parts, thus eliminating wear.
2Loss of information
If the position sensor is mounted on the moving part, then real-time position feedback is achieved, but a permanently moving cable is required connecting the sensor to the control unit
Solution Approach 1:
Instead of mounting the sensor on the moving part and running a cable with it, the approach is inverted: the detector is mounted on the stationary housing while the magnetic target is placed on the moving plunger. This eliminates the need for a permanently moving cable while still providing real-time position feedback through the magnetic field interaction.
3Reliability
If the sensor remains stationary while detecting moving parts, then robustness and wear are reduced, but the sensor must accurately measure absolute stroke of the plunger
Solution Approach 1:
The control unit continuously receives position signals from the fixed Hall effect detector and uses this feedback to calculate the absolute stroke of the plunger. By combining the stationary detector's reliable position readings with the known relationship between plunger and valve body positions, the system achieves accurate absolute stroke measurement without the detector needing to move.
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 solution enhances the robustness and maintainability of the braking assistance system, reduces design costs, and provides a more reliable braking mechanism by decoupling the sensor from the moving parts, allowing for easier sensor replacement and improved structural design freedom.
Implementation Method 1
the sensor is a Hall effect sensor suitable for measuring the speed and amplitude of the diver's displacement
Implementation Method 2
the target is fixed on the plunger and comprises at least one magnetic circuit suitable for spectrometry Rutherford backscattering
Data Source
Figure 1
Figure 2
Figure 3~5
AI summary
The invention concerns a brake assist device (1) for a motor vehicle, comprising a master cylinder (3), a control rod (10) and a moving part (5) enclosing a valve body (20) receiving a plunger (14), in which said part is a hollow cylinder capable of being moved in translation by a geared motor (8), said plunger is capable of being moved in translation by said rod connected to a brake pedal (12) that can be actuated by a driver (38), said valve body comprises, at an end opposite to said rod, a probe (21) capable of pressing against a reaction disk (22) of said master cylinder in such a way as to control said braking, characterised in that it comprises a position sensor (23) of said plunger, a controller (9) capable of calculating (43) a position of said valve body and controlling said probe as a function of said positions.