Steering System Power Electronics Fault Tolerance
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Solution Overview
Problem
Automated driving steering systems require improved reliability with minimal redundancy of components to prevent sudden failures during communication faults between the steering control unit and power electronics.
Innovation Solution
The steering system incorporates a permanently excited synchronous motor connected to a toothed rack via a gear, with power electronics that store future steering control commands for continued operation in case of communication failures, and includes a warning device to alert the driver to take over, ensuring stable operation until takeover.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the steering system is designed with high fault tolerance through component redundancy, then reliability is improved, but device complexity and cost increase
Solution Approach 1:
The power electronics store future steering control commands in advance (preliminary action) so that when a communication fault occurs, the system can continue operating using pre-stored commands rather than requiring redundant hardware components. This approach maintains reliability while avoiding the complexity of full system redundancy.
2Reliability
If communication protocols include future steering control commands, then fault tolerance is improved, but data transmission volume and processing load increase
Solution Approach 1:
The system transmits only the necessary portion of future steering control commands (partial action) - specifically just enough commands to cover the takeover time interval - rather than transmitting all possible future commands. This reduces data transmission volume while maintaining adequate fault tolerance.
3Duration of action of moving object
If the system stores multiple future steering control commands, then operation continuity during faults is improved, but memory requirements and data management complexity increase
Solution Approach 1:
The power electronics store only the minimum necessary number of future steering control commands - sufficient to cover the driver takeover time interval - rather than storing an excessive number of commands. This maintains operation continuity while minimizing memory requirements and data management complexity.
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
The system maintains functionality during communication faults, providing time for the driver or vehicle system to respond, ensuring safety and reliability with reduced redundancy in components.
Implementation Method 1
an electric motor, wherein the steering control unit (2) generates steering control commands on the basis of data from environmental sensors (10), wherein the steering control commands are converted by the power electronics (4) into control signals for the electric motor (5), which in turn controls the means (6) for adjusting the steering angle
Data Source
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AI summary
The invention relates to a steering system (1) for an automated driving process of a motor vehicle. The steering system (1) has at least one steering controller (2), a power electronics unit (4), means for adjusting a steering angle, and an electric motor (5). The steering system (1) is designed such that the steering controller (2) generates steering control commands dependent on the data of a surroundings sensor system (10). The steering control commands are converted into actuation signals for the electric motor (5) by the power electronics unit (4), and the electric motor then actuates the means for adjusting the steering angle. The steering controller (2) is designed to generate a current steering control command (A0) for a point in time t0 and at least one future steering control command (A-1) for a point in time t-1 dependent on the data of the surroundings sensor system (10) and to transmit the steering control commands to the power electronics unit (4), wherein t1>t0. The power electronics unit (4) has a storage unit (12) in which the at least one future steering control command (A-1) is stored, and the power electronics unit (4) is designed such that the at least one future steering control command (A-1) is converted into actuation signals for the electric motor (5) in the event of a communication fault between the steering controller (2) and the power electronics unit (4).