Intersection Speed Control Switching at Stop Signals
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Solution Overview
Problem
Existing vehicle control devices maintain limit control when approaching intersections with stop-instructing traffic signals, leading to prolonged vehicle passage times and increased risk of contact with other objects, as they fail to transition back to vehicle speed maintaining control without driver intervention.
Innovation Solution
A vehicle control device equipped with a camera and electronic control unit that determines the entrance reaching condition based on image data, ending limit control and resuming vehicle speed maintaining control when the vehicle approaches an intersection, thereby reducing passage time and risk of contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If limit control is maintained when approaching an intersection with a stop-instructing traffic signal, then the vehicle speed is kept low for safety, but the passage time through the intersection is prolonged increasing the risk of contact with other objects
Solution Approach 1:
The control device dynamically switches between limit control and vehicle speed maintaining control based on the detected distance to the stop-instructing traffic signal. When the distance is equal to or less than a threshold, limit control is executed to reduce vehicle speed for safety. When the distance exceeds the threshold (entrance reaching condition), the device transitions to vehicle speed maintaining control to reduce passage time. This dynamic adaptation resolves the contradiction by adjusting the control mode according to real-time conditions.
2Speed
If limit control is executed to reduce vehicle speed before a stop-instructing traffic signal, then the acceleration is controlled to be lower than maintaining acceleration, but the vehicle passes through the intersection at significantly low speed causing prolonged passage time
Solution Approach 1:
The control device implements periodic evaluation of the distance to the stop-instructing traffic signal and alternates between two control modes: limit control (when distance ≤ threshold) and vehicle speed maintaining control (when distance > threshold). This periodic switching based on distance evaluation allows the system to optimize between speed control and passage efficiency at different stages of approaching the intersection.
3Reliability
If the vehicle maintains significantly low speed through the intersection due to continuous limit control, then safety during approach is improved, but the possibility of contact with other objects in the intersection increases
Solution Approach 1:
The control device continuously monitors the distance to the stop-instructing traffic signal and uses this feedback to determine whether to maintain limit control or transition to vehicle speed maintaining control. When the distance exceeds the threshold (indicating the vehicle has reached the entrance to the intersection), the feedback mechanism triggers a switch to speed maintaining control, thereby reducing passage time and contact risk while having already ensured safety during the approach phase.
Data Source
AI summary
A vehicle control device is configured to: execute vehicle speed maintaining control for causing the vehicle speed to coincide with a set vehicle speed; start first control, for causing the acceleration to coincide with target acceleration for keeping maintaining acceleration no higher than limit acceleration, or second control, for controlling the acceleration such that the vehicle speed is kept no higher than a limit vehicle speed lower than the set vehicle speed, as limit control when a traffic signal correlated distance correlated with a traffic signal distance to a stop instructing traffic signal is determined to become a first threshold or less during execution of the vehicle speed maintaining control; and suspend the vehicle speed maintaining control and the limit control when a driver operates a deceleration operator during execution of the limit control.