Steer-by-Wire Steering Wake-Up via Motor Voltage Sensing
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Solution Overview
Problem
Existing steer-by-wire steering systems in motor vehicles do not efficiently detect and respond to driver input during idle states, such as when parked, leading to potential safety risks due to unexpected rotational resistance changes.
Innovation Solution
The system senses electrical voltage changes in the electric machine to detect steering handle rotation, activating an active state with counter torque when a threshold is reached, ensuring minimal energy consumption and rapid response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the electric machine is placed in a control-free idle state to save energy, then energy consumption is reduced, but the system cannot detect driver input or provide safety counter torque
Solution Approach 1:
The system performs preliminary monitoring of electrical voltage during the idle state to detect driver input before full activation is needed. This allows the system to prepare for potential driver interaction while maintaining energy savings, and immediately provide counter torque when rotation is detected, ensuring safety without continuous power consumption.
Solution Approach 2:
The patent replaces continuous mechanical monitoring with electrical voltage monitoring to detect steering handle rotation. By measuring the electrical voltage generated during rotation, the system can detect driver input with minimal energy consumption while maintaining the ability to provide safety counter torque when needed.
2Reliability
If the electric machine continuously monitors steering handle rotation, then driver input is detected reliably, but energy consumption increases
Solution Approach 1:
Instead of continuous monitoring, the system uses periodic voltage threshold checks during the idle state. The control unit wakes up periodically or upon detecting voltage changes exceeding a threshold, providing reliable driver input detection only when necessary while maintaining energy efficiency during extended idle periods.
3Speed
If the machine is activated immediately upon any steering handle movement, then driver input is responded to quickly, but false activations occur from minor movements
Solution Approach 1:
The system changes the parameter for activation from any movement detection to threshold-based voltage change detection. By setting a predetermined voltage threshold that corresponds to meaningful driver input, the system achieves rapid response to genuine driver actions while filtering out false activations from minor vibrations or unintended movements.
4Ease of operation
If the steering handle can rotate freely during idle state, then ease of operation is improved, but safety risks increase from unexpected resistance changes
Solution Approach 1:
The system applies preliminary anti-action by detecting driver input through voltage monitoring and immediately providing counter torque when rotation exceeds the threshold. This prevents the harmful effect of unexpected resistance changes by being ready to counteract driver input moments after detection, maintaining both ease of operation and safety.
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
This method efficiently and safely detects driver intent during idle states, providing counter torque to maintain steering handle position, reducing injury risks and energy waste.
Implementation Method 1
an electrical voltage of the electric machine is sensed in the idle state in order to detect a rotational movement of the steering handle
Implementation Method 2
the electric machine is controlled to generate a reset torque counteracting the rotational movement of the steering handle
Data Source
AI summary
A method for operating a steering device of a motor vehicle according to the steer-by-wire principle, wherein the steering device comprises a rotatable steering handle, in particular steering wheel, to provide a steering request, wherein the steering device comprises an electric machine mechanically coupled to the steering handle, wherein the electric machine is actuated in an active state of the steering device to generate a reset torque counteracting a rotational movement of the steering handle, and wherein the machine is control free in an idle state of the steering device. It is provided that, in the idle state, an electrical voltage of the electric machine is sensed to detect a rotation of the steering handle, and that, if the electrical voltage at least reaches a predetermined threshold value, and in particular exceeds it, the active state is activated.