Vehicle Motion Control System for Trajectory Deviation Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional deceleration control systems for vehicles cannot effectively control the travel trajectory, especially on low-μ roads or when driving at high speeds, leading to deviations from the intended path despite controlling yaw motion.
Innovation Solution
A vehicle motion control system that includes sensors for steering angle, vehicle speed, and lateral acceleration, calculating a reference lateral acceleration and required longitudinal force to adjust vehicle speed and trajectory, with feedback control and dead zones to stabilize the vehicle's path and prevent deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If deceleration control is performed based on reference target yaw rate calculated from steering angle and vehicle speed, then the yaw motion of the vehicle can be controlled, but the travel trajectory of the vehicle cannot be controlled and may deviate from the intended path
Solution Approach 1:
The control device calculates a target vehicle speed based on the steering angle and actual vehicle speed, and performs deceleration control when the actual vehicle speed exceeds the target vehicle speed. This feedback mechanism ensures that the vehicle speed is adjusted to maintain the intended travel trajectory, thereby improving trajectory accuracy while maintaining yaw motion control.
Solution Approach 2:
The control device calculates the target vehicle speed in advance based on the steering angle and actual vehicle speed before the trajectory deviation occurs. By performing preliminary speed adjustment, the system prevents trajectory deviation rather than correcting it after occurrence, improving both trajectory accuracy and response time.
2Speed
If the vehicle travels around a curve of a low-μ road or enters a curve at high speed, then the vehicle can maintain high-speed performance, but the trajectory deviates outward despite yaw rate control
Solution Approach 1:
The control device continuously monitors the actual vehicle speed and compares it with the target vehicle speed calculated from the steering angle. When the actual speed exceeds the target speed during curve travel on low-μ roads, deceleration control is activated to adjust the trajectory, thereby maintaining both high-speed performance and trajectory accuracy.
Solution Approach 2:
The control device dynamically adjusts the vehicle speed parameter based on the steering angle and road conditions. By changing the speed parameter in real-time during curve travel, the system compensates for trajectory deviations caused by low friction coefficients, maintaining both speed and trajectory accuracy.
3Manufacturing precision
If deceleration control is activated frequently to correct trajectory deviations, then the trajectory accuracy can be improved, but the driving stability deteriorates due to frequent changes in required longitudinal force
Solution Approach 1:
The control device calculates the target vehicle speed in advance based on the steering angle and actual vehicle speed, and activates deceleration control before significant trajectory deviation occurs. This preliminary action reduces the frequency of control activations while maintaining trajectory accuracy, thereby preserving driving stability.
Solution Approach 2:
The control device performs preliminary deceleration control to prevent trajectory deviation before it occurs, rather than reacting to frequent deviations. This preliminary anti-action reduces the need for frequent corrective actions, maintaining both trajectory accuracy and driving stability.
Data Source
AI summary
A vehicle motion control system includes: a steering angle sensor for detecting a steering angle; a vehicle speed sensor for detecting a vehicle speed; a lateral acceleration sensor for detecting an actual lateral acceleration of a vehicle body; a reference lateral acceleration calculation unit configured to calculate a reference lateral acceleration from the steering angle and the vehicle speed; a required longitudinal force calculation unit configured to calculate a required longitudinal force for reducing a deviation of the actual lateral acceleration relative to the reference lateral acceleration; and a longitudinal force control unit configured to control an output of at least one of a brake and a power plant such that the required longitudinal force is generated.