Vehicle Travel Control for Downhill Coasting Mode Switching
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Solution Overview
Problem
Existing travel control devices fail to sufficiently reduce energy consumption when vehicles travel downward slopes during coasting travel due to reliance on gradient information alone, leading to suboptimal switching between cruise and coasting travel modes.
Innovation Solution
A travel control device that utilizes gradient information and deviation variables to determine switching to coasting travel, considering factors like road gradient, inter-vehicle distance, and vehicle acceleration, to enhance energy efficiency by increasing the frequency of coasting travel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the travel control device switches to coasting travel based solely on gradient information, then the switching decision is simple, but the energy consumption reduction is insufficient on downward slopes with varying gradients
Solution Approach 1:
The system changes the parameters used for switching decisions from only gradient information to multiple parameters including gradient information and deviation variables. This allows the system to adapt to varying downward slope conditions and achieve sufficient energy consumption reduction while maintaining manageable complexity through structured parameter integration.
2Use of energy by moving object
If the system increases the frequency of switching to coasting travel, then energy consumption is reduced, but vehicle speed and distance control may be compromised
Solution Approach 1:
The system introduces feedback mechanisms by calculating deviation variables that compare actual vehicle behavior against expected behavior during coasting travel. This feedback allows the system to monitor and adjust switching decisions to maintain appropriate vehicle speed and distance control while increasing coasting travel frequency for energy savings.
Solution Approach 2:
The system performs preliminary calculations of deviation variables before switching to coasting travel, using gradient information and vehicle state data to predict whether coasting will be beneficial and safe. This preliminary assessment ensures that switching decisions maintain reliability while enabling more frequent coasting transitions.
Data Source
AI summary
A travel control device is configured to execute: a coasting travel process; a cruise travel process, a gradient information acquisition process acquiring, as gradient information, information indicating a gradient of a road surface on which a vehicle is traveling; a deviation variable acquisition process acquiring a deviation variable for determining an acceleration generated in the vehicle when the vehicle travels, by performing the coasting travel process, a downward slope having a predetermined gradient; and a switching process using the gradient information and the deviation variable as inputs and performing switching to the coasting travel process according to a value of the deviation variable even though a magnitude of the gradient of the road surface is different from a reference value.