Dynamic Engine Speed Limits for Fuel-Efficient Truck Shifting
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Solution Overview
Problem
Existing engine speed control systems in vehicles, such as those in the long-haul trucking industry, are inefficient, leading to higher fuel consumption and increased operating costs, and may frustrate drivers by being too limiting or not effectively optimizing shifting strategies.
Innovation Solution
Implementing an electronic control unit (ECU) that dynamically adjusts engine speed limits based on current transmission gear ratio, using sensors to detect engine speed and vehicle conditions, and adjusts fuel or air supply to maintain engine speed within an optimal range, influencing driver shifting strategies for improved fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed speed look-up tables are used for engine control, then device complexity is reduced, but adaptability to varying driver demands and environmental conditions deteriorates
Solution Approach 1:
The patent implements dynamic speed look-up tables that are regenerated in real-time based on current operating conditions including driver demand signals and environmental factors. This transforms the static control approach into a dynamic one, allowing the system to adapt to varying conditions while maintaining the simplicity of the look-up table structure. The dynamic regeneration occurs during vehicle operation, enabling the control system to respond to changing conditions without requiring complex pre-programmed tables.
2Adaptability or versatility
If dynamic speed look-up tables are implemented, then adaptability to varying conditions is improved, but computational load and processing time increase
Solution Approach 1:
The patent pre-calculates and stores multiple speed look-up tables for different operating conditions (e.g., different driver demand levels, temperature ranges, altitude conditions) before vehicle operation. During operation, the system selects and uses the appropriate pre-generated table based on current conditions, or interpolates between adjacent tables. This preliminary preparation eliminates the need for complex real-time calculations, reducing processing time while maintaining adaptability to varying environmental conditions.
3Device complexity
If conventional throttle-based control is used, then device complexity is minimized, but emission control precision and fuel efficiency deteriorate
Solution Approach 1:
The patent replaces the conventional mechanical throttle-based control system with an electronic control system that uses regenerated speed look-up tables to directly control engine parameters. This substitution allows for more precise control of air-fuel ratio, ignition timing, and other combustion parameters, thereby improving emission control precision and fuel efficiency. The electronic control system processes driver demand signals and environmental data to generate optimized speed profiles, replacing the indirect mechanical throttle control with direct electronic parameter management.
Data Source
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AI summary
In some embodiments, a vehicle is provided having improved fuel economy by using gradual engine speed control. Once a governor activation threshold is crossed, a dynamic engine speed limit that gradually increases over time is implemented. In some embodiments, if the engine speed does not continue to rise over time, increases in the dynamic engine speed limit may be paused. In some embodiments, if the engine speed increases at too great of a rate for too long of a time, the dynamic engine speed limit may be reset. In some embodiments, increasing, pausing, and/or resetting the dynamic engine speed limit allows gradual acceleration while also avoiding torque lock.