Wheel Counter-Torque Sampling for Robust Speed-Over-Ground Sensing
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Solution Overview
Problem
Existing methods for determining vehicle speed over ground in heavy-duty vehicles, particularly under challenging conditions, are unreliable and costly, with GPS, camera, and radar systems prone to errors and inefficiencies, while wheel slip-based control requires accurate speed over ground measurements that are difficult to obtain robustly.
Innovation Solution
A VMM system applies a transient counter-torque to wheels to un-slip them from their current torque state, allowing faster and more accurate wheel speed sampling for speed over ground determination, using wheel speed sensors and IMUs to enhance estimation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS, camera, or radar systems are used to determine vehicle speed over ground, then measurement capability is provided, but cost increases and reliability decreases in challenging environments
Solution Approach 1:
The patent replaces expensive electronic measurement systems (GPS, camera, radar) with a mechanical approach using wheel speed sensors and torque-generating devices. By applying transient counter-torque to wheels and measuring the resulting free-rolling wheel speed, the system obtains accurate vehicle speed over ground measurements without requiring complex electronic sensors, thus reducing cost while maintaining measurement capability.
2Productivity
If wheel speed sensors are used to determine vehicle speed over ground during torque application, then measurement is obtained, but accuracy decreases due to wheel slip
Solution Approach 1:
The patent applies transient counter-torque to wheels in advance of the measurement process to eliminate wheel slip. By temporarily applying torque in the opposite direction to the current applied torque, the system brings the wheel to a free-rolling state before measuring wheel speed, ensuring that the measurement reflects true vehicle speed over ground rather than slipped wheel speed.
Solution Approach 2:
The patent applies counter-torque as a preliminary anti-action to counteract the effect of applied torque that causes wheel slip. By applying torque in the opposite direction, the system neutralizes the slip condition and creates optimal measurement conditions where wheel speed accurately represents vehicle speed over ground.
3Ease of operation
If torque is applied to wheels for vehicle motion control, then motion control is achieved, but wheel slip increases making speed measurement unreliable
Solution Approach 1:
The patent implements periodic transient counter-torque applications to wheels at strategically chosen moments when accurate speed measurement is needed. This periodic intervention temporarily eliminates wheel slip for measurement purposes without permanently disrupting the torque application needed for vehicle motion control, thus maintaining both motion control capability and measurement reliability.
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 provides rapid and reliable vehicle speed over ground measurements, reducing latency and improving wheel slip control by accurately bridging periods of high wheel slip with IMU data, ensuring efficient and precise vehicle motion management.
Implementation Method 1
By applying a counter-torque in this manner a mechanical impulse is generated at the wheel which 'un-slips' the wheel from its state of slip
Data Source
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AI summary
A vehicle motion management, VMM, system (360) for a heavy-duty vehicle (100), the system comprising at least one wheel speed sensor (106) configured to output a wheel speed signal indicative of a rotation speed of a wheel (102, 310) on the vehicle (100), and at least one torque-generating device (320, 340) arranged to apply torque to the wheel (102, 310), where the VMM system (360) comprises processing circuitry (910) arranged to determine at least the direction of a current applied torque at the wheel (102, 103), and in preparation for determining wheel speed by the wheel speed signal, to apply a transient amount of torque to the wheel (102, 310) by the torque-generating device (320, 340) during a limited time period in a direction opposite to the direction of the current applied torque at the wheel (102, 310).