Engine Torque Control via Manifold Pressure and Cylinder Deactivation
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Solution Overview
Problem
Traditional engine control systems fail to accurately control engine output torque and do not provide rapid responses to control signals, nor coordinate torque control among various devices affecting engine output.
Innovation Solution
An engine control system comprising a desired manifold absolute pressure module, a MAP to torque module, a threshold determination module, and a fuel economy mode module, which determines desired operating conditions and selectively triggers cylinder deactivation or low-lift modes based on torque requests to optimize fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional engine control systems are used, then the system structure is simple, but the engine output torque control accuracy is insufficient
Solution Approach 1:
The control system is segmented into multiple functional modules: a desired MAP module that determines target manifold pressure, a MAP to torque module that converts pressure signals to torque values, a threshold determination module that sets entry/exit criteria, and an FE mode module that executes mode transitions. This modular segmentation enables precise torque control through coordinated operation of specialized subsystems.
Solution Approach 2:
The system implements feedback control by continuously monitoring actual engine torque output and comparing it with desired torque values. The FE mode module uses this feedback to determine when to enter or exit fuel economy modes, adjusting operational parameters dynamically to maintain accurate torque control while optimizing fuel efficiency.
2Speed
If traditional engine control systems are used, then the device complexity is low, but the response speed to control signals is slow
Solution Approach 1:
The system performs preliminary calculations by pre-determining desired MAP values and corresponding torque outputs before mode transitions are needed. The threshold determination module pre-calculates entry and exit torque thresholds, enabling the FE mode module to execute rapid mode switches without computational delays during critical response moments.
Solution Approach 2:
The control system dynamically adjusts operational modes based on real-time torque requests and engine conditions. The FE mode module can rapidly transition between different operational states (fuel economy mode vs. normal mode) by dynamically modifying cylinder deactivation strategies and throttle control parameters in response to changing demand conditions.
3Reliability
If traditional engine control systems are used, then the control coordination among devices is insufficient, but the system complexity is reduced
Solution Approach 1:
The control system integrates multiple functions into a coordinated framework: the desired MAP module simultaneously considers torque requirements and fuel economy objectives, the MAP to torque module provides a unified conversion mechanism, and the FE mode module coordinates cylinder deactivation with throttle control. This multi-functional integration ensures reliable torque control across diverse operating conditions.
Solution Approach 2:
The system merges torque control, fuel economy optimization, and mode management functions into an integrated control architecture. The FE mode module combines cylinder deactivation control, throttle positioning, and torque threshold management into a single coordinated decision-making process, ensuring that all control devices work together harmoniously to achieve both torque accuracy and fuel efficiency.
4Use of energy by moving object
If fuel economy modes are activated, then the fuel efficiency is improved, but the torque output capability is reduced
Solution Approach 1:
The system changes operational parameters by transitioning between different fuel economy modes (e.g., varying degrees of cylinder deactivation, different throttle positions, adjusted spark timing). These parameter adjustments optimize fuel consumption for light-to-moderate torque demands while maintaining the ability to quickly revert to full-power modes when high torque is required, thus balancing fuel efficiency with torque capability.
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
The system achieves precise control of engine torque output, improves fuel economy, and enables rapid response to torque requests by selectively activating or deactivating engine cylinders and adjusting air-fuel mixtures, thereby enhancing overall engine performance.
Implementation Method 1
determining a desired manifold absolute pressure (MAP) for operation of an engine in one of a cylinder deactivation mode and a low-lift mode based on a difference between a desired vacuum and an air pressure upstream of a throttle valve
Implementation Method 2
selectively triggers operation in the one of the cylinder deactivation mode and the low-lift mode based on a comparison of the entry torque and a torque request
Implementation Method 3
optimize fuel efficiency
Implementation Method 4
Internal combustion engines combust an air and fuel mixture within cylinders to drive pistons, which produces drive torque
Implementation Method 5
Air flow into the engine is regulated via a throttle. More specifically, the throttle adjusts throttle area, which increases or decreases air flow into the engine
Implementation Method 6
A fuel control system adjusts the rate that fuel is injected to provide a desired air/fuel mixture to the cylinders
Implementation Method 7
In spark-ignition engines, spark initiates combustion of an air/fuel mixture provided to the cylinders
Implementation Method 8
In compression-ignition engines, compression in the cylinders combusts the air/fuel mixture provided to the cylinders
Data Source
AI summary
An engine control system includes a desired manifold absolute pressure (MAP) module, a MAP to torque module, a threshold determination module, and a fuel economy (FE) mode module. The desired MAP module determines a desired MAP for operation of an engine in one of a cylinder deactivation mode and a low-lift mode based on a difference between a desired vacuum and an air pressure upstream of a throttle valve. The MAP to torque module determines a desired torque output of the engine for operation in the one of the cylinder deactivation mode and the low-lift mode based on the desired MAP. The threshold determination module determines an entry torque based on the desired torque output. The FE mode module selectively triggers operation in the one of the cylinder deactivation mode and the low-lift mode based on a comparison of the entry torque and a torque request.