Vehicle Inertial Travel Speed Control via Energy Prediction
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Solution Overview
Problem
Existing vehicle automatic travel control systems fail to accurately maintain vehicle speed within a set range during inertial travel, leading to early deviations and decreased fuel economy due to factors like air resistance, rolling resistance, and slope changes.
Innovation Solution
A vehicle automatic travel control device and method that calculates the end point speed using energy conservation laws or motion equations, incorporating vehicle weight, start point speed, slope, and horizontal distance to ensure the vehicle remains within the set speed range, thereby optimizing inertial travel distance and fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the vehicle is controlled to perform inertial travel on descending roads, then fuel economy is improved, but the vehicle speed may decrease to become less than the set lower limit speed at an early stage due to air resistance, rolling resistance, and slope resistance
Solution Approach 1:
The system performs preliminary calculation of the end point speed using energy conservation laws or motion equations before initiating inertial travel. By predicting the speed at the end point based on vehicle weight, start point speed, slope, and horizontal distance, the control device can determine in advance whether inertial travel will maintain the vehicle within the speed range, thus preventing early speed deviation while enabling fuel-efficient inertial travel when conditions are favorable.
2Device complexity
If the inertial travel is enabled based only on slope and slope change ratio, then the control is simple, but the vehicle speed becomes less than the set lower limit speed at an early stage in cases where the vehicle is not actually adjacent to the top
Solution Approach 1:
The system incorporates feedback by calculating the end point speed based on actual vehicle parameters (weight, start point speed, slope, horizontal distance) and comparing it with the speed range requirements. This feedback mechanism allows the control device to accurately determine whether inertial travel will maintain speed within acceptable limits, preventing premature speed deviation while avoiding unnecessary inertial travel initiation in cases where the vehicle is not actually adjacent to the top.
3Use of energy by moving object
If the vehicle performs inertial travel for longer distance, then fuel economy is improved, but the vehicle may deviate from the set speed range at an early stage
Solution Approach 1:
The control device performs preliminary calculation of the end point speed using energy conservation laws or motion equations before initiating inertial travel. By predicting the speed at the end point based on vehicle weight, start point speed, slope, and horizontal distance, the system can determine in advance whether inertial travel will maintain the vehicle within the speed range. This preliminary assessment enables the vehicle to perform inertial travel for the maximum possible distance while guaranteeing speed range maintenance, thus resolving the contradiction between extending inertial travel distance for fuel economy and maintaining reliable speed control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Accurately maintaining vehicle speed within the set range during inertial travel extends the distance traveled in this mode, significantly improving fuel economy by preventing early deviations and optimizing energy use on descending and ascending roads.
Implementation Method 1
calculates the end point speed using energy conservation laws or motion equations
Implementation Method 2
calculates the end point speed using energy conservation laws or motion equations
Implementation Method 3
influences of an air resistance, a rolling resistance and a slope resistance to be applied to the vehicle
Implementation Method 4
influences of an air resistance, a rolling resistance and a slope resistance to be applied to the vehicle
Implementation Method 5
influences of an air resistance, a rolling resistance and a slope resistance to be applied to the vehicle, depending on the slope of the descending road
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
An end point speed vi at an end point Pi of inertial travel that a vehicle 10 is controlled to perform in a short section li is calculated using a weight M, a start point speed vi-1, slopes θi, θi-1, and a horizontal distance Δx, based on a change in energy E of the vehicle 10 or an acceleration a of the vehicle 10 in the short section li. In a case where the calculated end point speed vi is within a speed range R1, the vehicle 10 is controlled to perform inertial travel in the short section li. In this way, the speed of the vehicle in a case where the vehicle is controlled to perform inertial travel can be accurately calculated and the vehicle can be prevented from deviating from a set speed range at an early stage even when controlled to perform inertial travel, thereby increasing the distance travelled by inertial travel and effectively increasing fuel economy.