Vehicle Control Apparatus Using Coordinate Transformation for Six-Degree-of-Freedom Motion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vehicle control methods fail to accurately account for six degrees of freedom motion, leading to discrepancies between control targets and actual vehicle behavior due to acceleration, steering, and inertia forces, and impose a high calculation load on vehicle control devices.
Innovation Solution
A vehicle control apparatus that calculates the center of gravity six-component and tire three-component using a coordinate transformation with normalization by driving and cornering stiffness, allowing for high degree of freedom control calculations while reducing computational load, and selects appropriate calculation methods based on the number of control requests and actuator degrees of freedom.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the Lagrange multipliers method and constraint conditions are used to calculate driving force of each wheel, then the control precision is improved, but the calculation load increases
Solution Approach 1:
The patent changes the calculation parameters from using Lagrange multipliers with constraint conditions to using coordinate transformation with normalization. This parameter change maintains control precision by still considering six degrees of freedom motion while reducing computational complexity through a more efficient mathematical approach that avoids iterative optimization.
Solution Approach 2:
The patent substitutes the mechanical calculation system (Lagrange multipliers method requiring iterative optimization and constraint satisfaction) with a coordinate transformation system that directly computes wheel forces through matrix operations. This substitution eliminates the need for complex iterative calculations while preserving the physical accuracy of six-degree-of-freedom motion modeling.
2Device complexity
If the conventional method is used to calculate vehicle motion, then the calculation process is simplified, but the control accuracy deteriorates due to ignoring six degrees of freedom motion
Solution Approach 1:
The patent introduces six-degree-of-freedom motion parameters (including pitch, roll, and vertical acceleration) into the calculation model, transforming it from a simplified two-degree-of-freedom plane motion model. This parameter expansion captures the actual vehicle dynamics under acceleration and steering conditions, significantly improving control accuracy without requiring complex iterative methods.
Solution Approach 2:
The patent uses coordinate transformation as an intermediary mathematical tool to bridge the gap between the simplified control input and the complex six-degree-of-freedom vehicle motion. This intermediary transformation enables accurate calculation of wheel forces while keeping the overall calculation process efficient and suitable for real-time control.
3Productivity
If the coordinate transformation with normalization is used, then the calculation efficiency is improved, but the adaptability to different control scenarios may be reduced
Solution Approach 1:
The patent designs the coordinate transformation with normalization to be a universal calculation framework that can handle multiple control scenarios (acceleration, deceleration, steering, and combined operations) through a single unified mathematical model. The normalization process automatically adapts to different operating conditions, maintaining calculation efficiency across diverse scenarios without requiring scenario-specific algorithms.
Data Source
AI summary
A vehicle control apparatus comprising, a center of gravity six-component calculation unit for calculating a center of gravity six-component as vehicle motion targets based on a driver input, a tire three-component calculation unit for calculating a tire three-component of four wheels of a vehicle based on the center of gravity six-component, a vehicle control unit for performing vehicle control by the vehicle control, actuator group based on the tire three-component of the four wheels, and wherein the tire three-component calculation unit calculates the tire three-component of the four wheels from the center of gravity six-component by a coordinate transformation without repetition, which is normalization with the driving stiffness of each wheel and the cornering stiffness of each wheel, when the number of control requests in the vehicle control is less than degrees of freedom of the vehicle control actuator group.