Electric Drive Braking Torque Compensation for Circuit Failure
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Solution Overview
Problem
Conventional braking systems in vehicles with high front-axle load and uneven weight distribution, especially in hybrid or electric vehicles, struggle to maintain effective deceleration when one brake circuit fails, due to the added weight of electric components and altered weight distribution.
Innovation Solution
A control device and method that utilize an electric drive and/or generator device to detect and compensate for brake circuit failures by applying additional braking torque or drive torque, adjusting the target mode based on sensor inputs and battery state of charge, allowing for safe braking even with impaired circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If an axle-by-axle brake circuit distribution is used in vehicles with high front-axle load, then the brake system structure is simplified and production costs are reduced, but the braking reliability deteriorates when one brake circuit fails
Solution Approach 1:
The electric drive device acts as an intermediary compensation mechanism. When a brake circuit failure is detected, the control device activates the electric drive device to generate compensating braking force, bridging the gap between the failed hydraulic system and the required braking performance. This mediator approach allows the simplified axle-by-axle configuration to achieve reliability comparable to more complex systems.
Solution Approach 2:
The system dynamically changes operational parameters by switching from pure hydraulic braking to a hybrid mode combining hydraulic and electric braking. The control device adjusts the electric drive device's torque output based on the detected failure condition, transforming the braking system's operational characteristics to maintain required deceleration performance despite circuit impairment.
2Reliability
If the electric drive device is used to compensate for brake circuit failures, then braking reliability is improved, but the device complexity increases
Solution Approach 1:
The electric drive device is designed with multi-functionality, serving both as a drive motor for vehicle propulsion and as a backup braking mechanism. The control device leverages the existing electric drive infrastructure for safety functions, eliminating the need for separate dedicated backup braking components. This universal approach improves reliability while minimizing additional device complexity.
Solution Approach 2:
The control device utilizes the vehicle's existing sensor network and communication systems to detect brake circuit failures and activate compensation. The electric drive device's control infrastructure is repurposed for safety functions, allowing the system to serve itself rather than requiring entirely separate detection and control systems. This self-service approach maintains reliability improvements without proportionally increasing complexity.
3Reliability
If generator braking torque is applied to compensate for brake circuit failure, then braking effectiveness is maintained, but energy management complexity increases
Solution Approach 1:
The control device implements a feedback mechanism that continuously monitors brake circuit status and vehicle deceleration performance. When a failure is detected, the system adjusts the electric drive device's generator mode torque output based on the detected deficiency and actual braking response. This closed-loop feedback ensures effective braking compensation while dynamically optimizing energy management, preventing excessive complexity through adaptive rather than purely predetermined control strategies.
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 safe and effective braking by compensating for brake circuit failures, eliminating the need for an X-brake circuit split, reducing production costs and complexity, and maintaining high safety standards across various vehicle weight distributions.
Implementation Method 1
a generator braking torque can be generated by means of the electric drive and/or generator device
Implementation Method 2
a drive torque can be exerted on the at least one wheel and/or the at least one axle by means of the electric drive and/or generator device
Data Source
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AI summary
The invention relates to a control device (10) for a braking system equipped with an electrical drive device and/or a generator device (58) and having a first receiver by means of which a predetermined parameter (14) with respect to a brake pressure can be received in at least one wheel brake cylinder (54a, 54b) of at least one brake circuit (50, 52), a second receiver by means of which an actual value (18) with respect to a pressure can be received in the at least one brake circuit (50, 52) and/or the brake pressure can be received in the at least one wheel brake cylinder (54a, 54b), and a control device by means of which a target mode of the electrical drive device and/or generator device (58) can be determined on the basis of the received predetermined parameter (14) and the received actual value (18), and a corresponding control signal (26) can be output to the electrical drive device and/or generator device (58) so that the electrical drive and/or generator device (58) can be controlled by means of the control signal (26) in the determined target mode. The invention further relates to a method for operating a braking system equipped with an electrical drive device and/or a generator device (58).