Vehicle Control Device Air Density Torque Adjustment
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Solution Overview
Problem
Low air density conditions, such as in highland areas, lead to reduced engine torque and deteriorated fuel economy due to the engine reaching its upper limit torque at intermediate accelerator pedal openings, resulting in decreased driving performance.
Innovation Solution
A vehicle control device and method that calculates a target engine output and torque based on air density, adjusting the target engine output to be smaller and target engine torque to be larger when air density is low, ensuring optimal fuel consumption and preventing torque limits, thereby maintaining driving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the target engine torque is increased to compensate for low air density, then the fuel economy is improved, but the engine torque reaches an upper limit value at intermediate accelerator pedal openings, reducing driving performance
Solution Approach 1:
The patent applies dynamics by making the target engine torque dynamically adjustable based on air density conditions. The system switches between two different target engine torque settings (first setting for standard air density, second setting for low air density) depending on detected air density levels, allowing the engine to adapt its torque characteristics to environmental conditions while maintaining both fuel economy and driving performance
Solution Approach 2:
The patent changes the target engine torque parameter based on air density measurements. When air density is determined to be below a threshold, the system modifies the target engine torque calculation to account for the reduced air density, thereby maintaining optimal fuel consumption characteristics while preventing the engine torque from reaching unrealistic upper limits that would degrade driving performance
2Use of energy by moving object
If the target engine torque is calculated based on standard air density, then the optimal fuel consumption line is achieved, but the actual engine torque becomes lower than target when air density is low, deteriorating fuel economy
Solution Approach 1:
The patent implements feedback by continuously monitoring air density and using this information to adjust the target engine torque calculation. The air density detection unit provides real-time feedback about environmental conditions, and the target engine torque calculation unit uses this feedback to modify torque targets appropriately, ensuring accurate fuel economy control adapts to actual operating conditions
Solution Approach 2:
The system changes the target engine torque parameter based on measured air density values. When air density falls below a predetermined threshold, the system adjusts the target engine torque to reflect the reduced oxygen availability, thereby maintaining accurate fuel consumption control that accounts for actual atmospheric conditions rather than assuming standard density
3Speed
If the engine torque is increased to maintain driving performance in low air density, then the vehicle responsiveness is improved, but the fuel economy deteriorates due to operating away from the optimal fuel consumption line
Solution Approach 1:
The patent applies dynamics by implementing a dynamic target engine torque setting that adapts to air density conditions. In low air density environments, the system dynamically adjusts the target torque to achieve appropriate vehicle responsiveness while maintaining fuel efficiency, rather than using a fixed torque target that would require excessive fuel consumption to achieve the same performance level
Data Source
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AI summary
A vehicle control device for controlling a vehicle with an engine includes a target engine output calculation unit configured to calculate a target engine output based on a target drive force, a vehicle speed and an air density, and a target engine torque calculation unit configured to calculate a target engine torque based on the target engine output and the air density. The target engine output calculation unit is configured to set a smaller target engine output when the air density is low than when the air density is high, and the target engine torque calculation unit is configured to set a larger target engine torque when the air density is low than when the air density is high.