Yaw-Rate-Based Articulation Angle Estimation for Combination Vehicles
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Solution Overview
Problem
Existing methods for estimating articulation angles in combination vehicles, such as trucks and trailers, are inaccurate during steering changes and unstable conditions, relying on error-prone sensors like cameras.
Innovation Solution
A computer system estimates articulation angles using yaw rates, longitudinal speeds, wheelbase lengths, and coupling lengths of vehicle units, employing trigonometric models and machine learning, without requiring additional expensive sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If articulation angle is estimated based on steering wheel angle, then the estimation can be obtained from simple sensor data, but the estimation becomes inaccurate immediately after steering direction changes or during instability events
Solution Approach 1:
The patent introduces yaw rate sensors and longitudinal acceleration sensors as intermediary measurement devices to indirectly determine articulation angle. Instead of directly measuring the angle or relying on steering wheel angle, the system uses these intermediary sensors to capture vehicle motion characteristics that can be processed to obtain accurate articulation angle data even during steering changes and instability events
Solution Approach 2:
The patent replaces the mechanical/geometric relationship-based estimation (steering wheel angle) with a sensor-based measurement system using yaw rate and longitudinal acceleration sensors. This substitution allows the system to directly measure vehicle motion dynamics rather than inferring articulation angle from steering inputs, thereby improving accuracy during dynamic maneuvers
2Measurement precision
If camera-based sensors are used to measure articulation angle, then direct measurement is possible, but the sensors are error-prone and expensive
Solution Approach 1:
The patent replaces expensive camera-based sensing systems with cheaper, more reliable sensor data that is already available in vehicle systems. By using yaw rate sensors, longitudinal acceleration sensors, wheelbase length data, and coupling length data that are standard in vehicle manufacturing, the system achieves cost-effective articulation angle estimation without relying on expensive specialized sensors
Solution Approach 2:
The patent enables the vehicle system to self-determine its articulation angle using data that is already being collected for other vehicle functions. The yaw rate, longitudinal acceleration, wheelbase, and coupling length data are utilized from existing vehicle systems rather than requiring separate dedicated measurement systems, thereby reducing overall system complexity and cost
Data Source
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AI summary
A computer system (700) comprising processing circuitry (702) configured to estimate an articulation angle for a combination vehicle (100) is provided. A second vehicle unit (2) is connected to a first vehicle unit (1) at a first coupling point (cpi) forming a first articulation angle. The processing circuitry (702) is configured to estimate the first articulation angle (ψ1) based on a first indication, a longitudinal speed (vx1) along a first longitudinal axis (axi) of the first vehicle unit (1), a wheelbase length (lwb2) of the second vehicle unit (2), and a coupling length (lc1) between a rear axle group (ragi) of the first vehicle unit (1) and the first coupling point (cp1). The first indication is indicative of a first yaw rate (ωz1) of a first vehicle unit (1) and/or of a towing articulation angle (ψ0) between the first vehicle unit (1) and a towing vehicle unit (0).