Multi-Mode Engine Torque Control with Boost Constraints

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Solution Overview

Problem

Traditional engine control systems fail to accurately control engine output torque, particularly in boosted engines and those with multiple operating modes, leading to inadequate response to control signals and coordination among devices affecting torque output.

Innovation Solution

A control method that selects an optimal multiple-step operating mode by prioritizing variable capacity modes based on fuel efficiency, applying torque and noise/vibration constraints, and conducting mode determination arbitration to identify necessary changes, incorporating boost as a constraint and using thresholds for mode transitions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional engine control systems are used, then the system is simple to operate, but the engine output torque control accuracy is insufficient

Engineering Contradiction:

Improveengine output torque control accuracyVSAvoidcontrol system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The control system is segmented into multiple independent mode selection modules, each responsible for evaluating specific operating modes (e.g., cylinder deactivation modes, valve timing modes). This segmentation allows complex multi-mode control to be broken down into manageable subsystems, improving torque control accuracy while keeping each module's complexity manageable

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The control system dynamically selects between multiple operating modes based on real-time engine conditions and torque requirements. The mode selection is not fixed but adapts continuously, allowing the system to achieve high control accuracy by matching the most appropriate mode to current operating conditions

Inventive Principle:

Principle #15Dynamics

2Loss of energy

If multiple operating modes are implemented, then fuel efficiency is improved, but the response speed to control signals deteriorates

Engineering Contradiction:

Improvefuel efficiencyVSAvoidresponse speed to control signals

Core Design Contradiction:

Loss of energyVSSpeed

Solution Approach 1:

The control system pre-evaluates and pre-positions multiple operating modes based on anticipated torque requirements and engine conditions. By having modes pre-configured and ready, the system can switch between them rapidly without the delay of real-time calculation, thus maintaining fast response speed while utilizing multiple fuel-efficient modes

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system changes operational parameters (such as cylinder activation states, valve timing parameters) to select different modes. These parameter changes are implemented through controlled transitions that optimize both fuel efficiency and response characteristics, allowing the system to balance energy loss reduction with acceptable response times

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If multiple operating modes are implemented, then fuel efficiency is improved, but coordination among devices affecting torque output deteriorates

Engineering Contradiction:

Improvefuel efficiencyVSAvoidcoordination complexity among devices

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The control system implements a universal mode selection framework that coordinates multiple devices (cylinder deactivation system, valve timing system, fuel injection system) through a single integrated decision-making process. This universal coordinator ensures that all torque-affecting devices work together harmoniously across different operating modes, improving fuel efficiency while maintaining coordination through centralized control logic

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Loss of energy

If mode selection is optimized for fuel efficiency, then energy loss is reduced, but the device complexity increases

Engineering Contradiction:

Improvefuel efficiencyVSAvoidmode selection system complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The mode selection system optimizes fuel efficiency by changing key operational parameters (cylinder activation state, valve timing parameters) rather than requiring complete system redesign. By focusing parameter changes on the most impactful variables, the system achieves significant fuel efficiency improvements with relatively limited increases in control complexity

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10364765B2Method to select optimal mode on a multi-mode engine with charging

Publication Date: 2019.07.30 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A control method for selecting an optimal multiple step operating mode for a multiple cylinder motor vehicle engine system having variable lift includes prioritizing each of a full torque capacity (FTC) mode having all cylinders operating at high lift, a first reduced capacity economy mode (RCE1) having all cylinders operating at low lift, and a second reduced capacity economy mode (RCE2) having fewer than all of the cylinders operating at low lift with at least one cylinder deactivated based on predicted fuel economy of each of the modes. Multiple constraints are applied to each of the prioritized modes including incorporating boost as one of the constraints by calculating a maximum torque capacity for each mode that is a function of a current boost pressure. A mode determination arbitration is conducted to identify if a change in mode is required.