Vehicle Start-Stop System Using Range-Rate Prediction
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Solution Overview
Problem
Existing vehicle engine start-stop systems struggle to accurately anticipate driver power demands, leading to inefficient fuel economy and increased emissions due to false engine starts and stops during stop-and-go traffic, and lack of detection for distracted drivers.
Innovation Solution
A vehicle system utilizing sensors to generate range and range-rate signals, a processing device to determine if the front vehicle is moving away, and a user interface to alert the driver, which includes a driver monitoring system to detect distraction, ensuring the engine only starts when the front vehicle exceeds a predetermined envelope of movement and the driver is attentive.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine is turned off when the vehicle stops to improve fuel economy, then fuel consumption decreases, but the engine may fail to start in time when power demand is required
Solution Approach 1:
The system performs preliminary action by detecting front vehicle movement and anticipating driver power demand before the driver actually presses the accelerator. The processing device predicts power demand based on front vehicle acceleration, and the engine control device prepares to start the engine in advance, ensuring the engine is ready before power is needed while still allowing it to remain off during extended stops for fuel economy.
Solution Approach 2:
The system uses feedback by continuously monitoring front vehicle movement, calculating range-rate, and using this information to predict driver power demand. The system adjusts engine start timing based on this feedback loop, balancing fuel economy with reliable engine availability when needed.
2Reliability
If the engine starts whenever the front vehicle moves to ensure power availability, then power demand is met, but false engine starts occur during minor movements like traffic signal stops
Solution Approach 1:
The system applies dynamics by using a dynamic threshold approach where the range-rate threshold is adjusted based on vehicle speed and operating conditions. At higher speeds or when the vehicle is already moving, smaller movements trigger engine starts, while at low speeds during traffic signals, larger movements are required. This dynamic adaptation prevents false starts from minor movements while ensuring power availability when genuinely needed.
Solution Approach 2:
The system changes parameters by modifying the range-rate threshold based on vehicle speed and operating conditions. The threshold is not fixed but varies dynamically, allowing the system to distinguish between significant movements requiring power and minor movements during normal traffic flow, thereby preventing false engine starts while maintaining reliable power response.
3Use of energy by moving object
If the system monitors front vehicle movement closely to predict power demand accurately, then fuel economy improves, but the system complexity increases
Solution Approach 1:
The system achieves multi-functionality by using the existing radar or sensor that already measures range to the front vehicle for multiple purposes: collision avoidance, adaptive cruise control, and now power demand prediction. The same sensor data is processed to calculate range-rate and predict driver intent, eliminating the need for separate sensors and reducing overall system complexity while improving fuel efficiency.
Solution Approach 2:
The system applies self-service by using the vehicle's existing sensor infrastructure and processing capabilities to perform power demand prediction. The same processing device that handles other vehicle functions analyzes front vehicle movement data, and the engine control device uses this information autonomously without requiring additional dedicated components, thereby maintaining fuel efficiency gains while minimizing added complexity.
Data Source
AI summary
A vehicle system having at least one sensor configured to output a range signal and a range-rate signal. The range signal represents a distance from a host vehicle to the front vehicle and the range-rate signal represents range-rate information of the front vehicle relative to the host vehicle. A processing device is configured to output an alarm signal based on the range signal, the range-rate signal, and whether a driver of the host vehicle is determined to be distracted.