Brake Clamping Force Sensing Using Wear Sensors and Stiffness Maps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Monitoring brake application force in commercial vehicles is costly and requires significant maintenance due to the need for force sensors, which can be avoided by utilizing wear sensors and stiffness maps to calculate application force.
Innovation Solution
The method involves reading travel signals from wear sensors, using predefined stiffness maps to calculate actual application force, and accounting for state-dependent stiffness values such as temperature and wear, eliminating the need for separate force sensors and reducing maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If force sensors are installed to monitor brake application force, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent introduces a stiffness map as an intermediary element that translates wear sensor travel signals into application force information. Instead of directly measuring force with a force sensor, the system uses the stiffness map (stored in memory) to calculate application force from displacement measurements, thereby avoiding the need for complex force sensing hardware while maintaining measurement capability
Solution Approach 2:
The patent replaces the mechanical force sensing system with a computational approach. Rather than using physical force sensors to directly detect application force, the system substitutes a combination of wear sensors (measuring travel) and a stiffness map (providing state-dependent stiffness values) that calculates force through signal processing, eliminating the need for mechanical force measurement hardware
2Measurement precision
If force sensors are installed to monitor brake application force, then measurement precision is improved, but maintenance effort increases
Solution Approach 1:
The stiffness map serves as a computational intermediary that processes simple travel signals from wear sensors into meaningful application force data. This approach eliminates force sensors which require calibration and maintenance, replacing them with a software-based solution stored in memory that requires no physical maintenance
Solution Approach 2:
The wear sensor continues to serve its primary function of monitoring brake wear while simultaneously providing the travel signals needed for application force calculation. This self-service approach means the same sensor performs multiple functions without requiring additional maintenance, as the stiffness map processing is automated and requires no manual intervention
3Device complexity
If wear sensor signals are analyzed with stiffness maps to calculate application force, then device complexity is reduced, but measurement precision may be compromised
Solution Approach 1:
The patent applies parameter changes by using state-dependent stiffness values in the stiffness map that account for temperature, wear state, and brake type. These varying parameters allow the system to adapt the calculation to current brake conditions, maintaining measurement precision across different operating scenarios without requiring complex hardware
Solution Approach 2:
The stiffness map is designed to be dynamic, with stiffness values that change based on brake state parameters such as temperature and wear level. This dynamic adaptation allows the system to maintain accurate application force determination throughout the brake's operational life and across varying conditions, despite using simpler sensor equipment
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a method (1000) for monitoring a brake (100) of a motor vehicle, in particular a commercial vehicle, comprising the following steps: reading displacement signals from a wear sensor (115) arranged on the brake (100), providing a predefined stiffness map associated with the brake (100) in which condition-dependent stiffness values are stored, and calculating a clamping force Flst as a function of the displacement signals and the predefined stiffness map. The invention further relates to a control unit (10) and a vehicle system (10000).