CACC Speed Control Using Far-Forward Vehicle Data
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Solution Overview
Problem
Cooperative adaptive cruise control (CACC) systems face challenges in maintaining smooth and safe vehicle speed adjustments due to sudden starts or accelerations caused by relying solely on the speed of the target vehicle in front, without considering the dynamics of far-forward vehicles.
Innovation Solution
The CACC system incorporates a communication unit for V2V communications, an information collection unit using sensors, and a control unit to determine and select both a forward vehicle and a far-forward vehicle, allowing for speed control based on the combined driving information of both, thereby reducing sudden speed changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the CACC system adjusts speed based solely on the target vehicle's speed, then the control logic is simple, but sudden starts or accelerations occur frequently
Solution Approach 1:
The patent segments the single target vehicle concept into two distinct roles: forward vehicle (primary target) and far-forward vehicle (secondary target). This segmentation allows the system to differentiate between vehicles at different distances and apply appropriate control strategies to each, thereby smoothing speed adjustments while maintaining manageable control logic through modular processing.
2Device complexity
If the CACC system only monitors the forward vehicle, then the sensor processing is simple, but the vehicle cannot detect sudden lane changes by far-forward vehicles
Solution Approach 1:
The system performs preliminary monitoring of far-forward vehicles before they become an immediate collision risk. By continuously tracking the far-forward vehicle's position and lane status in advance, the system can detect potential lane changes early and proactively adjust speed to prevent sudden starts or collisions, thereby preventing information loss about lane changes.
3Loss of time
If the system uses only the forward vehicle's speed information, then the response time is short, but the speed adjustments are abrupt and uncomfortable
Solution Approach 1:
The system applies beforehand cushioning by using the far-forward vehicle's speed information to predict future speed requirements. This allows the CACC system to gradually adjust speed in advance rather than reacting abruptly to the forward vehicle's movements, thereby reducing sudden accelerations or decelerations and improving driving comfort while maintaining timely response through dual-vehicle monitoring.
Data Source
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AI summary
An apparatus and method for controlling a vehicle speed based on information about forward vehicles that travel in the same lane may be acquired using Vehicle to Everything (V2X) communications in a cooperative adaptive cruise control (CACC) system. The CACC system includes a communication unit receiving vehicle information from neighboring vehicles using V2V communications; an information collection unit collecting vehicle information of the neighboring vehicles and the subject vehicle using sensors; and a control unit determining a forward vehicle and a far-forward vehicle using the sensors, selecting first and second target vehicles for being followed by the subject vehicle based on the vehicle information of the forward vehicle and the far-forward vehicle and the vehicle information of the neighboring vehicles, and controlling the driving speed of the subject vehicle based on speed information of the first and second target vehicles.