Wheel Torque Friction Estimation Using a Lowerable Vehicle Anchor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for estimating sliding friction in vehicles, particularly heavy-duty equipment, often require significant tire force and sudden acceleration, leading to unreliable friction estimates and driver discomfort.
Innovation Solution
A system that uses a lowerable part of the vehicle to anchor it to the ground, applying a controlled force and torque to a wheel, allowing estimation of sliding friction based on the torque required to spin the wheel, using known parameters such as normal load and wheel radius.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If contemporary friction estimation methods are used (requiring 50% or more of maximum tire force), then sliding friction can be estimated, but driver comfort deteriorates and the method is not practical for normal operation
Solution Approach 1:
The system performs friction estimation during normal vehicle operation without requiring sudden accelerations or special maneuvers. By continuously monitoring wheel torque and slip during regular driving, the friction estimate is obtained in advance when needed, eliminating the need for disruptive test maneuvers that would discomfort the driver.
Solution Approach 2:
The vehicle's normal operation itself provides the data needed for friction estimation. The system uses torque and slip information already present during regular driving to estimate friction, turning the vehicle's own operational data into the measurement resource, rather than requiring separate test procedures.
2Measurement precision
If sudden acceleration is applied to reach 50% of max tire force for friction estimation, then friction can be measured, but vehicle motion becomes undesirable and causes driver discomfort
Solution Approach 1:
The system continuously estimates friction during normal operation, so the estimate is already available when the driver requests it. This eliminates the need for sudden accelerations at the moment of request, as the measurement is performed in advance during regular driving conditions.
Solution Approach 2:
Instead of requiring full 50% tire force utilization to estimate friction, the system uses partial torque applications encountered during normal driving. The continuous monitoring approach allows friction estimation from smaller, more frequent torque variations that occur naturally during operation.
3Ease of operation
If friction estimation is performed during normal operation without special maneuvers, then driver comfort is maintained, but reliable friction estimates are not readily available when needed
Solution Approach 1:
The system continuously performs friction estimation during normal vehicle operation, maintaining an up-to-date friction value ready for immediate use. This continuous process ensures that when the driver or control system requests a friction estimate, a reliable value is already available without requiring special maneuvers or waiting for specific driving conditions.
Solution Approach 2:
The system continuously monitors wheel torque and slip during normal operation and uses this feedback to update the friction estimate in real-time. This ongoing feedback loop ensures the friction value remains current and reliable, ready for immediate retrieval when needed by the driver or control systems.
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 accurate and comfortable estimation of sliding friction on demand, reducing stress on vehicle components and discomfort to the driver by using lowerable parts to anchor the vehicle and measure torque.
Implementation Method 1
determine a first torque as the applied torque required to make the at least one wheel start spinning
Implementation Method 2
estimate a sliding friction of the at least one wheel relative ground based on the first force and the first torque
Data Source
AI summary
A method of estimating a sliding friction of a vehicle or machine is provided, and includes pressing of at least one part of the vehicle or machine against ground with a first force; with the at least one part pressed against the ground, increasing a torque applied to at least one wheel of the vehicle or machine, and determining a first torque as the applied torque required to make the at least one wheel, or a track of the vehicle or machine driven by the at least one wheel, start spinning; and estimating a sliding friction of the at least one wheel, or of the track, relative ground based on the first force and the first torque. A corresponding computer system, vehicle or machine, computer program product and computer-readable storage medium are also provided.