Autonomous Vehicle Redundancy Braking via ESC and EPB Coordination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Autonomous vehicles face a dangerous situation when the main brake control unit fails, as existing technologies do not provide an effective method for generating braking force through cooperative control between the main brake, electronic stability control (ESC), and electronic parking brake (EPB).
Innovation Solution
A redundancy braking system that includes a redundancy braking control unit, which communicates with the main brake control unit and performs cooperative control between ESC and EPB to generate a calculated target braking force by replacing rear-wheel ESC braking force with rear-wheel EPB braking force, and adjusts front-wheel ESC braking force accordingly, based on mode determination and sensor information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the main brake control unit is used for braking, then braking force is generated effectively, but the system reliability deteriorates when the main brake control unit fails
Solution Approach 1:
The redundancy braking control unit is pre-configured with ESC and EPB control capabilities before the main brake control unit fails. When failure occurs, the system can immediately switch to redundancy braking without requiring complex real-time decision-making, thus maintaining reliability while managing complexity through pre-established control pathways.
Solution Approach 2:
The system incorporates ESC and EPB as backup braking mechanisms that are ready to compensate when the main brake control unit fails. This beforehand cushioning ensures that braking capability is maintained even when the primary system fails, directly addressing the reliability concern without requiring the driver to react.
2Reliability
If ESC braking force is used for redundancy braking, then braking force is generated, but the ESC performance deteriorates due to low endurance
Solution Approach 1:
The system uses periodic monitoring of ESC temperature and braking force requirements to determine when to switch between ESC and EPB. By periodically checking system status and adjusting the braking strategy, the ESC can operate at high capacity when needed while the EPB provides sustained braking capability, resolving the endurance limitation.
Solution Approach 2:
The system dynamically changes operating parameters by monitoring ESC temperature and adjusting the distribution of braking force between ESC and EPB. When ESC temperature increases, the system reduces ESC braking force and increases EPB contribution, allowing the ESC to operate within safe thermal limits while maintaining overall braking performance.
3Reliability
If rear-wheel ESC braking force is replaced with rear-wheel EPB braking force, then ESC is protected, but braking force homogeneity deteriorates
Solution Approach 1:
The system applies different braking strategies to different wheels based on local conditions. Front wheels continue to use ESC braking while rear wheels use EPB braking when the temperature threshold is exceeded. This local differentiation protects the ESC while maintaining braking homogeneity through coordinated control of all four wheels.
Solution Approach 2:
The system continuously monitors ESC temperature and braking force requirements, using this feedback to dynamically adjust the distribution of braking force between ESC and EPB. This closed-loop control ensures that braking homogeneity is maintained while protecting the ESC from thermal damage by reducing its load when necessary.
4Reliability
If cooperative control between main brake, ESC, and EPB is implemented, then braking force is satisfied, but control complexity increases
Solution Approach 1:
The redundancy braking control unit is pre-configured with control algorithms for coordinating ESC and EPB before the main brake control unit fails. This preliminary setup includes pre-defined control strategies for different failure scenarios, reducing the complexity of real-time decision-making while ensuring braking force requirements are met.
Solution Approach 2:
The redundancy braking control unit acts as an intermediary that manages the coordination between ESC and EPB when the main brake control unit fails. It receives braking force requirements and distributes them appropriately between the available braking mechanisms, simplifying the control complexity by centralizing the coordination function in a dedicated control unit.
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
Ensures effective braking force generation even in case of main brake failure, reduces heterogeneity of braking force, protects ESC with low endurance performance, and maintains safe operation by replacing rear-wheel ESC with EPB braking force and decreasing front-wheel ESC braking force.
Implementation Method 1
a main brake control unit configured to output a control signal so that a frictional braking force is generated to a main brake of the autonomous vehicle by hydraulic pressure
Implementation Method 2
perform cooperative control between electronic stability control (ESC) and an electronic parking brake (EPB) so that a calculated target braking force is satisfied
Data Source
AI summary
The present disclosure relates to a system and method for operating a main brake in case of a failure of an autonomous driving function of an autonomous vehicle. the system for operating the main brake in case of a failure of the autonomous driving function of the autonomous vehicle includes an autonomous driving control unit configured to perform control such that the autonomous vehicle travels in the autonomous driving mode, a main brake control unit configured to perform first communication with the autonomous driving control unit and to output a first control signal so that a frictional braking force is generated to a main brake by hydraulic pressure, and a regenerative braking control unit configured to perform second communication with the main brake control unit and to output a second control signal so that a regenerative braking force is generated to a motor.