Vehicle Control Device Yaw Angle Error Correction
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Solution Overview
Problem
Existing vehicle control systems face challenges in accurately estimating self-vehicle location, particularly at the start of travel, due to yaw angle estimation errors caused by initial phase shifts in pulsed waveforms between wheels and uncertainties in wheel speed pulse counts during temporary stops.
Innovation Solution
A vehicle control device calculates the change in yaw angle, travel distance, and forward/backward travel direction using sensor information from non-steered wheels, employing a vehicle-speed weighted average method to correct yaw angle errors and estimate self-vehicle location with high accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If dead reckoning using only wheel speed sensor is employed, then device complexity is reduced, but measurement precision of yaw angle deteriorates
Solution Approach 1:
The patent changes the parameter of yaw angle calculation from discrete pulse counting to continuous integration of angular velocity. By integrating angular velocity over time, the system achieves finer resolution and continuous measurement of yaw angle, resolving the contradiction between simple sensor configuration and precise measurement.
2Measurement precision
If time average filter processing is applied to yaw angle, then measurement precision is improved, but reliability in acceleration and deceleration ranges deteriorates
Solution Approach 1:
The patent applies dynamic filtering that adapts to vehicle motion states. The filter characteristics change based on whether the vehicle is accelerating, decelerating, or cruising, allowing high precision during steady-state travel while maintaining reliability during transient acceleration and deceleration phases.
3Measurement precision
If angular speed from wheel speed is used, then measurement precision is improved, but reliability deteriorates due to error accumulation during start and stop
Solution Approach 1:
The patent detects vehicle start and stop states in advance and applies corrective actions during these critical phases. By identifying transient periods where error accumulation occurs and applying specific corrections, the system prevents reliability deterioration while maintaining high measurement precision during normal operation.
4Reliability
If conventional yaw angle correction method is applied, then reliability during straight travel is improved, but adaptability to turning travel deteriorates
Solution Approach 1:
The patent develops a universal yaw angle correction method that functions effectively for both straight travel and turning travel. The correction algorithm adapts to different travel modes, providing reliable performance across diverse driving scenarios rather than being limited to straight-line motion only.
Data Source
AI summary
Provided is a vehicle control device capable of accurately estimating a self-vehicle location with a yaw angle error occurring when a vehicle starts to travel due to an initial phase shift between pulsed waveforms of left and right wheels when the vehicle starts to travel suppressed. The vehicle control device further estimates a direction of wheel rotation while the vehicle is at a stop. A yaw angle deviation when the vehicle starts to travel is estimated and corrected on the basis of a weighted average of discrete yaw angle values obtained immediately after the vehicle starts to travel from wheel speed sensors installed on left and right non-steered wheels of the vehicle. A yaw angle while the vehicle is at a stop and a yaw angle when the vehicle starts to travel are also estimated, and the direction of wheel rotation while the vehicle is at a stop is also estimated from a difference between the yaw angles. The yaw angle and coordinates are corrected on the basis of the estimation result.