Steering Haptic Feedback via Dual Model Quotient
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Solution Overview
Problem
Existing electromechanical and electronic steering systems fail to provide a natural and dynamic haptic feedback to drivers, especially in critical driving situations, which can lead to inadequate driver feedback and potential safety issues.
Innovation Solution
A method that calculates a feedback force value by processing rack force values from two different models, a steering-system-based and a vehicle-data-based model, to generate a quotient that adjusts the steering reference torque, allowing for adaptive haptic feedback that simulates road conditions and provides dynamic information during critical maneuvers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single model is used to generate rack force values for haptic feedback, then the system is simple and reliable, but the steering feeling lacks naturalness and dynamic information in critical driving situations
Solution Approach 1:
The patent divides the single model into two separate models: a steering-system-based model and a vehicle-data-based model. Each model processes rack force values independently, allowing the system to leverage both simple reliable feedback and complex adaptive feedback simultaneously. The steering-system-based model provides stable baseline feedback while the vehicle-data-based model adds dynamic information about road conditions and vehicle state.
Solution Approach 2:
The patent merges the outputs of two different models by calculating a quotient between their rack force values. This combination allows the system to integrate the reliability of the steering-system-based model with the adaptability of the vehicle-data-based model, creating a composite feedback signal that provides both natural steering feeling and dynamic information about critical driving situations.
2Adaptability or versatility
If multiple models are used to process rack force values, then the steering feeling becomes more natural and informative, but the device complexity increases
Solution Approach 1:
The patent introduces a quotient calculation as an intermediary mechanism between the two models. Rather than directly integrating complex model outputs through multiple processing stages, the system uses a simple quotient operation (ratio) to compare the rack force values from both models. This intermediary approach simplifies the integration process while still capturing the essential differences between model predictions to generate adaptive feedback.
Solution Approach 2:
The patent changes the processing parameter from direct model output integration to a quotient-based comparison. By transforming the rack force values into a ratio, the system reduces computational complexity while maintaining the ability to detect deviations that indicate critical driving situations. This parameter transformation allows adaptive feedback without requiring complex integration algorithms.
3Loss of information
If high feedback force is provided to give dynamic information, then driver awareness improves, but the steering feeling becomes less comfortable in normal driving conditions
Solution Approach 1:
The patent implements dynamic adjustment of feedback characteristics based on the quotient value. When the quotient indicates normal driving conditions (values close to 1), the system provides smooth, comfortable feedback. When the quotient deviates significantly from 1, indicating critical situations like understeer or oversteer, the system dynamically increases information feedback to alert the driver. This dynamic adaptation allows the system to optimize between comfort and information provision based on real-time driving conditions.
Solution Approach 2:
The patent uses the quotient of the two model outputs as a feedback signal to modulate the haptic feedback characteristics. The system continuously monitors the agreement between the steering-system-based model and vehicle-data-based model, and uses this feedback to adjust the amount of dynamic information provided to the driver. This feedback mechanism ensures that high information feedback is only provided when necessary, maintaining comfort during normal operation.
Data Source
AI summary
In a method for producing a haptic feedback force by setting a manual torque at a steering intention input device of a steering system of a motor vehicle, a first and a second rack force value are obtained from two different models. The rack force values originating from the two models are processed to form a quotient, which determines a feedback force value, by the second rack force value being modified by the quotient, and the feedback force value is transferred to a steering reference torque generator of the steering system, which sets the manual torque at the steering intention input device in dependence on the feedback force value.