Vehicle Control Device Switching Criteria for Stable Distance
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Solution Overview
Problem
Conventional autonomous vehicle control systems face instability in shifting control conditions due to unstable vehicle-to-vehicle distances, leading to mode hunting and driver irritation, particularly when the distance becomes less than a predetermined value, causing sudden acceleration or deceleration and sensor malfunction issues.
Innovation Solution
A vehicle control device with a switch controller, recognizer, first distance calculator, and second distance calculator that switches control conditions based on a predetermined threshold difference between actual and target vehicle-to-vehicle distances, ensuring stable shifts by automating more operations when the difference is within a set range, thereby reducing driver workload and preventing mode hunting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the control condition is switched based on vehicle-to-vehicle distance being equal to or less than a predetermined value, then the switching response is fast, but the control condition becomes unstable and mode hunting occurs
Solution Approach 1:
The patent applies dynamics by making the switching determination threshold adaptive rather than fixed. The threshold is dynamically adjusted based on the relative velocity between host vehicle and preceding vehicle, allowing the system to respond quickly when appropriate while maintaining stability when conditions are marginal. This resolves the contradiction by making the switching criterion flexible rather than rigid.
Solution Approach 2:
The patent changes the parameter used for switching determination from a fixed distance threshold to a dynamic threshold that varies with relative velocity. When relative velocity is high, the threshold increases to prevent premature switching; when relative velocity is low, the threshold decreases to enable timely switching. This parameter change resolves the contradiction between fast response and stability.
2Measurement precision
If the vehicle-to-vehicle distance threshold is set low for quick switching, then the switching sensitivity is high, but false switching occurs due to distance instability
Solution Approach 1:
The patent changes the threshold parameter from a fixed low value to a dynamic value that incorporates relative velocity. This allows the system to maintain high sensitivity (low threshold) when relative velocity is low (stable following condition) while reducing sensitivity (high threshold) when relative velocity is high (unstable condition), thus preventing false switching while maintaining appropriate sensitivity.
Solution Approach 2:
The patent introduces feedback by using relative velocity information to adjust the switching threshold. The system continuously monitors relative velocity and adjusts the distance threshold accordingly, creating a feedback mechanism that prevents false switching while maintaining high switching sensitivity when conditions are appropriate.
3Adaptability or versatility
If the control condition switches frequently due to unstable distance, then the system is responsive to changes, but driver irritation increases due to mode hunting
Solution Approach 1:
The patent changes the switching criterion from a fixed distance threshold to a dynamic threshold based on relative velocity. This makes the system more adaptable by allowing switching when appropriate (maintaining responsiveness) while preventing unnecessary switching that would cause mode hunting and driver irritation.
Solution Approach 2:
The patent applies preliminary anti-action by using relative velocity information to predict and prevent unstable switching before it occurs. When relative velocity indicates potential instability, the threshold is adjusted to prevent switching, thereby preventing mode hunting and driver irritation before they can occur.
Data Source
AI summary
A vehicle control device which controls acceleration/deceleration of a vehicle includes: a switch controller; a recognizer; an actual vehicle-to-vehicle distance calculator; and a target vehicle-to-vehicle distance calculator. Switching criteria for the switch controller's switching the control condition from the first control condition to the second control condition include a criterion that the absolute value of a difference between an actual vehicle-to-vehicle distance calculated by the actual vehicle-to-vehicle distance calculator and a target vehicle-to-vehicle distance calculated by the target vehicle-to-vehicle distance calculator is less than or equal to a predetermined threshold.