Vehicle Speed Control System Using Periodic Engine Idle Modes
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Solution Overview
Problem
Current 'pulse and glide' technology for improving fuel economy is limited by acceleration perception and traffic dynamics, and existing idle coast methods have minor effects on fuel economy in normal driving conditions.
Innovation Solution
A speed control system that monitors the gas pedal position to determine a nominal speed and alternates between driving and idle modes based on predetermined speed fluctuations, using an electric motor and alternator to maintain constant speed or reduce deceleration during idle mode, allowing for extended idle periods without requiring cruise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If 'pulse and glide' technology is used to improve fuel economy, then fuel consumption is reduced, but acceleration perception and traffic dynamic flow are negatively impacted
Solution Approach 1:
The system implements periodic alternation between driving mode and idle mode based on monitored speed parameters. The control unit switches the engine between these modes periodically as the vehicle speed fluctuates around the nominal speed, enabling fuel savings through extended idle periods while maintaining acceptable acceleration perception through timely mode transitions.
Solution Approach 2:
The system dynamically adjusts engine operating modes based on real-time speed monitoring. When vehicle speed deviates from the nominal speed by more than the predetermined maximum value, the control unit switches between driving and idle modes, creating a dynamic response that adapts to changing driving conditions and maintains acceleration perception.
2Use of energy by moving object
If idle coast mode is used to stop or idle the engine during coasting, then fuel economy is improved slightly, but the effect is minor in normal driving conditions
Solution Approach 1:
The system extends idle mode duration by periodically switching between driving and idle modes based on speed fluctuations. This periodic action allows the engine to remain in idle mode for extended periods during normal driving conditions, significantly increasing fuel economy improvement beyond what traditional idle coast methods achieve.
Solution Approach 2:
The control unit continuously monitors vehicle speed and compares it to the nominal speed. When speed deviations exceed the predetermined maximum value, the system switches modes, creating a feedback mechanism that extends idle periods and amplifies fuel economy benefits in normal driving conditions.
3Use of energy by moving object
If the engine is frequently switched between driving and idle modes, then fuel consumption is reduced, but system complexity increases
Solution Approach 1:
The control unit uses simple feedback based on monitored speed parameters to determine when to switch between driving and idle modes. By relying on readily available speed data and predetermined thresholds, the system achieves fuel savings through automated mode switching without requiring complex control algorithms or additional sensors.
Solution Approach 2:
The system uses the vehicle's existing speed monitoring capabilities to automatically determine when to switch modes. The control unit self-regulates engine operation based on speed fluctuations, eliminating the need for additional complex control mechanisms while achieving extended idle periods and reduced fuel consumption.
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
Enables the use of 'pulse and glide' technology in normal driving conditions, optimizing fuel consumption by maintaining constant speed, reducing engine load, and improving combustion efficiency without negatively impacting acceleration perception.
Implementation Method 1
an electric motor which is configured to apply power to the vehicle to keep constant speed or reduce deceleration of the vehicle when the engine of the vehicle is set in an idle mode
Implementation Method 2
an alternator which, when the engine of the vehicle is set in an idle mode, is operated by said engine for supplying electric power to the electric motor
Data Source
Figure 1
AI summary
The present invention relates to a method for controlling the speed of a motor vehicle, a speed control system and a device for use with the speed control system. For improving the fuel economy, the method comprises monitoring at least one speed-related parameter of the vehicle (2), determining a nominal speed based on said speed-related parameter, setting the engine (3) of the vehicle (2) in a driving mode or an idle mode at said nominal speed, setting the engine (3) of the vehicle (2) in an idle mode when the actual speed of the vehicle exceeds said nominal speed, setting the engine (3) of the vehicle (2) in the driving mode when the actual speed of the vehicle decreases to said nominal speed or falls below said nominal speed, and repeating, based on said fluctuations of the actual speed of the vehicle, said changes between driving mode and idle mode as long as the monitored speed-related parameter is substantially unaltered. The speed control system used at this method comprises at least monitoring means (4), calculating means (6) and setting means (8).