Braking System Retarder Torque Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing brake systems face imprecision in controlling vehicle deceleration due to divergences between reported and actual braking torque from permanent brakes, leading to inaccurate deceleration control, especially in electronically controlled systems.
Innovation Solution
A method to accurately determine the braking effect of permanent brakes by calculating the differential slip and braking force correlation, allowing for precise calculation of continuous braking force without additional sensors, and using this information to improve deceleration control by adjusting service brake activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If permanent brake status messages are used to determine braking torque, then deceleration control can be implemented, but the control precision deteriorates due to temporal divergence between reported and actual braking torque
Solution Approach 1:
The invention uses wheel sensors to continuously monitor the rotational speeds of drive wheels and non-drive wheels, calculating actual vehicle deceleration in real-time. This feedback mechanism replaces reliance on delayed permanent brake status messages with direct measurement of the physical effect (deceleration), eliminating the temporal divergence problem and improving control precision.
Solution Approach 2:
The invention replaces the electronic communication-based torque reporting system (status messages) with a mechanical measurement system using wheel speed sensors. By directly measuring wheel speed differences and calculating deceleration from these mechanical parameters, the system obtains accurate real-time braking torque information without relying on delayed electronic status reports.
2Duration of action of stationary object
If permanent brakes are used to reduce service brake wear, then service brake lifespan is extended, but response time increases due to delayed permanent brake activation
Solution Approach 1:
The invention continuously monitors wheel speeds and calculates differential slip before service brakes are fully activated. By detecting changes in wheel speed differential and calculating the emerging braking torque from permanent brakes in advance, the system can prepare the coordinated braking response earlier, mitigating the delayed response characteristic of permanent brakes.
Solution Approach 2:
The invention implements dynamic calculation of permanent brake braking torque based on real-time wheel speed measurements and differential slip analysis. This dynamic approach allows the system to adapt the permanent brake contribution continuously as conditions change, optimizing the response time by actively managing the transition between permanent and service brake dominance rather than relying on fixed activation thresholds.
3Measurement precision
If additional sensors are installed to measure actual braking torque, then measurement precision improves, but device complexity and cost increase
Solution Approach 1:
The invention uses existing wheel speed sensors (already present in the vehicle for other functions) to measure the differential rotation between drive and non-drive wheels. By processing this existing data to calculate actual braking torque and vehicle deceleration, the system achieves precise measurement without adding new sensors, making the existing sensor network serve multiple functions including braking torque measurement.
Solution Approach 2:
The invention makes the existing wheel speed sensors serve multiple functions: they provide data for anti-lock braking systems, stability control, and now also for calculating permanent brake braking torque and vehicle deceleration. This multi-functional use of existing sensors achieves precise braking torque measurement without increasing device complexity or adding dedicated measurement devices.
Data Source
Figure 1
Figure 2~3
AI summary
The invention relates to a method for controlling a braking system of a vehicle (10), wherein the vehicle comprises at least one engine (12), an operating brake (20), and a parking brake (22), wherein a) a differential slip drive force correlation parameter (FK) is determined at least during an acceleration phase of the vehicle (10), and b) a parking brake force parameter (FDB) indicating the braking force generated by the parking brake (22) is determined at least during a brake actuating phase, using the differential slip (DS) occurring during braking, the differential slip drive force correlation parameter (FK), and the braking force portions (FV, FH) generated by the operating brake (20) of the vehicle, for determining the braking effect of the parking brake (22).