Vehicle Tire Force Optimization Using Stored Constraint States
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Solution Overview
Problem
Existing vehicle control apparatuses require multiple iterative calculations to obtain optimal tire three-component values, increasing computational load due to the need to repeatedly validate and invalidate constraints during optimization, especially when the center of gravity six-component is updated.
Innovation Solution
The vehicle control apparatus employs an active-set method to store the application state of constraints when an optimal solution is achieved, allowing subsequent calculations to start with valid constraints, reducing the number of iterative steps by initializing only changed constraints and omitting unnecessary validation processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the quadratic programming method with active-set method is used to calculate optimal tire three-component values, then the manufacturing precision of the control solution is improved, but the computational load increases due to multiple iterative calculations
Solution Approach 1:
The patent applies preliminary action by storing the constraint application state obtained from previous optimization calculations and reusing it as the initial state for subsequent calculations. This allows the system to skip unnecessary iterative steps when constraints have not changed, thereby reducing computational load while maintaining the precision benefits of the quadratic programming method with active-set method.
2Reliability
If the constraint validation is performed repeatedly in each iterative calculation, then the reliability of the optimal solution under constraint is improved, but the productivity of the calculation process deteriorates
Solution Approach 1:
The patent implements feedback by monitoring whether the constraint application state has changed between consecutive optimization calculations. When the constraint state remains unchanged, the system feedbacks this information to skip redundant validation steps, thereby maintaining solution reliability while significantly improving calculation productivity. The constraint validation is performed only when necessary, based on the feedback from state comparison.
3Productivity
If the number of iterative calculations is reduced by using stored constraint states, then the productivity of the calculation process is improved, but the difficulty of detecting and measuring the optimal solution may worsen
Solution Approach 1:
The patent prepares and stores the constraint application state from previous calculations as preliminary information for subsequent optimization processes. This preliminary action enables the system to quickly determine whether full iterative validation is necessary or if the stored state can be directly reused, thereby improving productivity without compromising the ability to detect and verify the optimal solution when needed.
Data Source
AI summary
A vehicle control apparatus configured to calculate a center of gravity six-component; calculate a tire three-component of each wheel for two or more wheels of a vehicle imposing a constraint on each wheel expressed as an inequality corresponding to upper and lower limits of the tire three-component; apply the constraint based on whether the constraint is valid or invalid for each of the wheels based on a predetermined optimum-condition for obtaining an optimum-solution under the constraint, and calculating an optimum-solution of the tire three-component of each wheel by performing a tentative-optimum-solution-calculation one or more times until the predetermined optimum-condition is satisfied; and store an application-state of the constraint when the optimum-solution satisfying the predetermined optimum-condition is obtained, and calculate the optimum-solution of the tire three-component of each wheel by using a stored value of the application-state of the constraint, in the next calculation of the optimum-solution.