ACC-PCC Coordination Using Conservative Acceleration Selection
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Solution Overview
Problem
Existing vehicle speed control systems face challenges in effectively merging the reactive driver comfort and safety features of Adaptive Cruise Control (ACC) with the proactive fuel economy and safety features of Predictive Cruise Control (PCC), particularly due to the reliance on accurate predictions and extensive computation in short horizon optimization.
Innovation Solution
A coordinating apparatus and method that communicates with both ACC and PCC systems, seamlessly selecting the lesser acceleration or greater deceleration between the target values provided by each system to ensure minimum disturbance to fuel economy, thereby integrating reactive and proactive features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If short horizon optimization is used to integrate ACC and PCC systems, then fuel economy is improved, but the system complexity and computational requirements increase
Solution Approach 1:
The patent segments the speed control function into two independent algorithms: ACC algorithm for reactive safety and comfort control, and PCC algorithm for proactive fuel economy optimization. Each algorithm operates independently and provides its own target acceleration/deceleration commands, which are then combined by selecting the more conservative value. This segmentation avoids the complexity of integrated optimization while preserving the benefits of both approaches.
Solution Approach 2:
The patent introduces a coordinating apparatus as an intermediary component that receives target acceleration/deceleration commands from both ACC and PCC algorithms and selects the appropriate command to execute. This mediator resolves conflicts between the two algorithms without requiring complex integration or re-tuning of either algorithm, thereby reducing system complexity while maintaining fuel economy benefits.
2Use of energy by moving object
If ACC and PCC are integrated through short horizon optimization, then fuel efficiency is improved, but accurate predictions and extensive computation are required
Solution Approach 1:
The patent divides the control function into separate ACC and PCC algorithms that independently compute their target acceleration/deceleration values. The ACC algorithm focuses on safety and comfort with reactive control, while the PCC algorithm optimizes for fuel economy using predictive models. By segmenting the computation, each algorithm can be optimized independently without requiring extensive joint computation, reducing overall computational burden.
Solution Approach 2:
The patent uses simplified, computationally inexpensive models for both ACC and PCC algorithms rather than complex integrated optimization. The PCC algorithm uses basic predictive models for road grade and traffic flow rather than sophisticated short horizon optimization, making the computation more tractable while still achieving fuel economy improvements.
3Reliability
If ACC priority is given over PCC in conflicting commands, then driver safety is maintained, but fuel economy optimization is reduced
Solution Approach 1:
The coordinating apparatus acts as a mediator that systematically compares ACC and PCC commands and selects the more conservative value. When ACC commands deceleration for safety reasons, it takes priority. When PCC commands moderate deceleration for fuel economy, it can be applied if ACC allows. This mediator ensures safety requirements are met while maximizing fuel economy within those constraints.
Solution Approach 2:
The patent changes the control parameter from binary priority selection to continuous comparison of target acceleration/deceleration values. Instead of simply giving ACC priority, the system compares the actual acceleration values from both algorithms and selects the one that provides safer or more fuel-efficient operation, allowing dynamic adjustment based on real-time conditions.
Data Source
AI summary
A Coordinating Apparatus and Method is provided between Adaptive Cruise Control (ACC) and Predictive Cruise Control (PCC). The ACC system is configured to provide a target acceleration or deceleration based on maintaining a target distance from vehicles ahead. The PCC system is configured to provide a target acceleration or deceleration based on upcoming changes in elevation and maximizing fuel economy. The coordinating apparatus communicates with the ACC system and with the PCC system, and applies the lesser acceleration or greater deceleration between the ACC target acceleration or deceleration and the PCC target acceleration or deceleration. The apparatus and method may apply the target acceleration or deceleration by way of a vehicle speed control apparatus, such as a vehicle engine controller.