Four-Wheel Behavior Control Using a Two-Wheel Vehicle Model
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Solution Overview
Problem
Existing technologies face challenges in accurately controlling the behavior of four-wheeled vehicles due to differences in tire slip angles and the complexity of arithmetic operations, leading to increased development costs and periods.
Innovation Solution
A vehicle behavior control device that utilizes a two-wheeled model to calculate velocity vectors for front and rear wheels, converting them into centroid behavior, and controls actuators to achieve desired steering and braking forces for each wheel, leveraging a simplified model to reduce computational complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a four-wheeled vehicle model with detailed tire slip angle analysis is used, then control accuracy is improved, but calculation complexity and development cost increase enormously
Solution Approach 1:
The patent segments the vehicle model into independent wheel units, where each wheel's behavior is calculated separately based on its own slip angle and ground contact load. This allows accurate four-wheeled vehicle control while simplifying the overall calculation structure by avoiding complex coupled equations.
Solution Approach 2:
The patent changes the modeling parameters from a unified four-wheeled vehicle model to individual wheel-level parameters (slip angle, ground contact load per wheel). This parameter transformation enables accurate representation of each wheel's behavior while reducing the complexity of the system equations.
2Device complexity
If a simplified two-wheeled model is used, then calculation complexity is reduced, but control accuracy deteriorates due to ignoring ground contact load and tire slip angle
Solution Approach 1:
The patent introduces wheel-specific parameters (individual slip angles and ground contact loads) that were missing in simplified models. By adding these parameters to the two-wheeled model framework, it achieves both computational simplicity and accurate representation of four-wheeled vehicle dynamics.
3Measurement precision
If complex calculation logic considering ground contact load and tire slip angle is constructed, then control accuracy is improved, but development period and cost increase
Solution Approach 1:
The patent segments the control logic into modular wheel-level calculations rather than requiring complex unified four-wheeled vehicle equations. This modular approach reduces development time by allowing independent calculation of each wheel's behavior while maintaining high control accuracy.
Data Source
AI summary
A vehicle behavior control device comprises an actuator group including one or more actuators configured to drive a vehicle having four wheels; and a vehicle behavior controller configured to control operation of the actuator group, wherein the vehicle behavior controller is configured to: apply a target motion to a two-wheeled model of a two-wheeled vehicle simulating the vehicle to calculate a velocity vector of a front wheel and a rear wheel, the velocity vector being necessary for obtaining the target motion, convert each of the velocity vector of the front wheel and the rear wheel into a centroid behavior, calculate a turning angle and a braking/driving force for each of the four wheels, based on the centroid behavior, and control the operation of the actuator group to enable each of the four wheels to output the turning angle and the braking/driving force that are calculated.