Vehicle Surface Friction Estimation from Steering During Stops
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Solution Overview
Problem
Current computing systems in vehicles lack the ability to accurately and efficiently determine friction on driving surfaces, which is crucial for safe navigation and control, especially in autonomous vehicles, as existing methods may disrupt passengers or fail to account for varying environmental conditions.
Innovation Solution
A vehicle computing system that uses operational data from wheel-based actions, such as steering, braking, and propulsion, to estimate friction by analyzing input torques, wheel rotations, and forces, allowing for friction determination during normal vehicle operations without significant disruption, and utilizing this data for improved motion planning and control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If wheel-based actions are initiated to determine friction, then friction estimation accuracy is improved, but vehicle operation disruption increases
Solution Approach 1:
The system performs friction determination during detected acceleration events, utilizing pre-identified opportunities when the vehicle is already undergoing motion changes. By detecting events such as acceleration, deceleration, or stops and initiating wheel-based actions during these predefined moments, the system obtains friction data without requiring separate dedicated testing maneuvers that would disrupt normal operation.
Solution Approach 2:
The vehicle uses its own operational movements (acceleration, deceleration, steering) to generate the wheel-based actions needed for friction measurement. Rather than requiring external testing equipment or separate calibration procedures, the vehicle's normal driving actions serve dual purposes: both transportation and friction characterization.
2Reliability
If multiple wheel-based actions are performed to account for varying environmental conditions, then measurement reliability is improved, but time consumption increases
Solution Approach 1:
The system continuously determines friction during detected acceleration events rather than performing discrete, time-consuming measurements. By utilizing every available acceleration event (acceleration, deceleration, steering maneuvers) as an opportunity to gather friction data, the system maintains continuous updates of friction characteristics without dedicating specific time blocks for measurement.
Solution Approach 2:
The system performs friction determination periodically whenever acceleration events are detected, rather than using continuous or intermittent fixed-interval measurements. This event-driven periodic action ensures friction data is obtained whenever relevant motion occurs, adapting the measurement frequency to actual driving conditions and reducing unnecessary measurements during steady-state operation.
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
Enables vehicles to safely navigate by providing accurate friction estimates, allowing for tailored movement and control based on the driving surface conditions, enhancing both autonomous and non-autonomous vehicle operations while minimizing passenger disruption.
Implementation Method 1
determining, based at least in part on the operational data, data indicative of a friction associated with a surface upon which the autonomous vehicle is traveling during the acceleration event
Data Source
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AI summary
Systems and methods are provided for generating data indicative of a friction associated with a driving surface, and for using the friction data in association with one or more vehicles. In one example, a computing system can detect a stop associated with a vehicle and initiate a steering action of the vehicle during the stop. The steering action is associated with movement of at least one tire of the vehicle relative to a driving surface. The computing system can obtain operational data associated with the steering action during the stop of the vehicle. The computing system can determine a friction associated with the driving surface based at least in part on the operational data associated with the steering action. The computing system can generate data indicative of the friction associated with the driving surface.