Electropneumatic Service Brake Valve Control Piston Actuation
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Solution Overview
Problem
Existing vehicle brake systems, particularly in autonomous driving scenarios, face challenges in ensuring fault-tolerant braking without driver intervention, as current systems either fail to maintain braking functionality upon electrical faults or are overly complex and costly due to redundant designs.
Innovation Solution
The introduction of a method and device where a second actuating force, generated independently by the electronic control device, acts on the control piston of the service brake valve device, allowing for automatic braking even in the absence of driver input, by using redundant pneumatic channels and an additional electrical service brake circuit to maintain braking functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a purely pneumatic backup control is used after electrical fault, then the system can maintain basic braking functionality, but automated braking control is lost and driver intervention is required
Solution Approach 1:
The patent uses pneumatic actuators and control mechanisms to enable automated braking. The service brake valve device includes pneumatic channels that can be controlled electronically through the control device, allowing automated generation of braking force via pneumatic pressure without direct driver intervention while maintaining reliability after electrical faults.
2Reliability
If completely redundant electronic brake control is implemented, then fault tolerance is improved, but system complexity and costs increase significantly
Solution Approach 1:
The patent merges electrical and pneumatic control systems into a unified service brake valve device. The control device can operate in electrical mode normally and automatically switch to pneumatic mode upon fault detection, combining the advantages of both systems while avoiding the need for completely separate redundant systems.
Solution Approach 2:
The service brake valve device is designed with multi-functionality, serving both as an electrical control interface during normal operation and as a pneumatic control mechanism during fault conditions. This universal design allows a single device to fulfill multiple functions, reducing overall system complexity while maintaining fault tolerance.
3Reliability
If electronic brake control switches off after fault, then system safety is maintained, but braking control capability is reduced
Solution Approach 1:
The control device is designed with preliminary fault detection and automatic mode switching capabilities. Before a complete system failure occurs, the system detects electrical faults and automatically transitions to pneumatic backup control, maintaining braking capability while ensuring safety through pre-planned fault response mechanisms.
Data Source
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Figure 2a
AI summary
The invention relates to a method for controlling an electropneumatic service brake device (124) actuated by an electropneumatic service brake valve device (1), in particular of an electronic braking system (EBS) of a motor vehicle, wherein the electropneumatic service brake valve device (1) has a service brake actuating mechanism (10) as well as, within at least one electrical service brake circuit of the electropneumatic service brake device (124), at least one electrical channel (130) comprising at least one electrical braking power sensor (67) actuated by the service brake actuating mechanism (10) in response to a driver's braking requirement, for actuation-dependent adjustment of actuation signals and with at least one control device [FBM-ECU] receiving the actuation signals, as well as at least one pneumatic channel (132, 134) inside at least one pneumatic service brake circuit of the electropneumatic service brake device (124), in which pneumatic channel (132, 134), by actuation of the service brake actuating mechanism (10) in response to a driver's braking requirement, at least one control piston (4, 12) of the service brake valve device (1) is acted upon with a first actuating force, and the control piston (4; 12) directly or indirectly controls at least one double-seat valve (34) of the service brake valve device (1) containing an inlet seat (64) and an outlet seat (32), in order to generate a pneumatic braking pressure or braking control pressure for the pneumatic wheel brake actuators (1, 18, 120). The invention provides that, in case of a braking requirement that is independent of the driver's desire, the at least one control piston (4; 12) of the service brake valve device (1) is acted upon by a second actuating force in addition to the first actuating force, or by a second actuating force instead of the first actuating force, which second actuating force acts on the at least one control piston (4; 12) in parallel to, and in the same direction or in the opposite direction relative to, the first actuating force, and independently of the driver's braking requirement, on the basis of the controlled electrical signals generated by the electronic control unit (FBM-ECU) of the service brake valve device (1).