External Adaptive Traffic Signal Control via Non-Linear Scheduling

The patent segments the traffic signal control into two independent parts: a fixed linear order (yield point sequence) that remains unchanged, and a variable state selection mechanism that dynamically chooses which phases to serve and in what order. This allows the system to maintain the simplicity and reliability of the fixed structure while adding dynamic adaptability through state selection, thereby improving traffic flow efficiency without proportionally increasing overall system complexity.

The patent introduces dynamics by allowing the controller to selectively change the sequence of phases served within the fixed linear order. Instead of serving phases in a rigid predetermined sequence, the system can dynamically select states (combinations of phases) to serve based on real-time traffic conditions, enabling adaptive response to varying traffic demands while preserving the underlying fixed structure for stability.

The patent applies preliminary action by pre-defining multiple possible states (phase combinations) and their corresponding yield points in the fixed linear order before traffic conditions change. The controller has these options prepared in advance and can quickly switch between them based on detected traffic conditions, avoiding the need for complex real-time calculations while still achieving adaptive response that reduces vehicle wait times.

The patent implements feedback by continuously monitoring traffic conditions (such as queue lengths, vehicle presence, or detector signals) and using this information to dynamically select which state to serve next from the fixed linear order. This closed-loop feedback mechanism enables the system to adapt to real-time traffic conditions, optimizing phase sequencing to minimize vehicle wait times and reduce congestion.

The patent segments the timing plan management into a fixed framework (linear order of yield points) and a dynamic selection layer (state choice). The fixed framework provides easy manageability and predictability, while the dynamic state selection optimizes green light allocation based on actual traffic demand. This segmentation allows the system to achieve high intersection throughput without proportionally increasing schedule management complexity.

The patent applies partial action by not requiring complete reconfiguration of the entire timing plan to achieve optimization. Instead, the system selectively adjusts only the necessary states (phase combinations) within the fixed linear order based on current traffic demand. This partial adjustment approach enables optimization of green light allocation to improve intersection throughput while keeping the overall schedule management complexity relatively low.