Dual Throttle Valve Torque Control via Model Predictive
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Solution Overview
Problem
Traditional engine control systems for internal combustion engines lack precision in controlling engine output torque and fail to provide rapid responses to control signals, as well as coordinate torque control among various devices affecting engine output.
Innovation Solution
The implementation of a system with a first throttle valve upstream of a turbocharger compressor, a charge air cooler, and a second throttle valve, controlled by an engine control module that uses model predictive control (MPC) to manage the throttle valves based on requests such as fuel vapor purging, icing prevention, catalyst light off, exhaust gas recirculation, and deceleration fuel cutoff, among others, to optimize torque, fuel consumption, emissions, noise, and vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional engine control system is used, then the system structure is simple, but the torque control precision is insufficient and response speed is slow
Solution Approach 1:
The control system is segmented into multiple independent control modules: a first throttle valve control module for upstream throttle positioning, a second throttle valve control module for downstream throttle positioning, a purge pump control module, and a coordinated control module. Each module operates semi-independently, allowing precise torque control through distributed decision-making while maintaining manageable system complexity through modular architecture.
Solution Approach 2:
The control system dynamically adjusts the opening degrees of the first and second throttle valves based on real-time torque requests and engine operating conditions. The control module continuously modifies valve positions to achieve rapid torque response, transitioning from static valve positioning to dynamic adaptive control that responds to changing drive conditions.
2Object-generated harmful factors
If the first throttle valve is closed to enable fuel vapor purging, then fuel vapor can be purged from the tank, but air flow into the engine is restricted
Solution Approach 1:
The air intake system is segmented into two separate throttle valves: the first throttle valve upstream of the turbocharger and the second throttle valve downstream. This segmentation allows the first throttle valve to close for fuel vapor purging while the second throttle valve remains open to maintain air flow to the engine, enabling simultaneous fuel vapor purging and sustained engine breathing capability.
Solution Approach 2:
The second throttle valve acts as an intermediary that compensates for the air flow restriction caused by closing the first throttle valve. When the first throttle valve closes to enable purging, the second throttle valve opens wider to maintain sufficient air flow to the engine, mediating between the conflicting requirements of vapor purging and air supply.
3Temperature
If the charge air cooler is used to cool compressed air, then air temperature is reduced, but icing may occur in cold conditions
Solution Approach 1:
The control module dynamically adjusts the opening degree of the first throttle valve based on ambient temperature conditions. When ambient temperature is low (below a predetermined threshold), the first throttle valve is prevented from closing completely or is kept partially open, dynamically adapting the purging strategy to avoid charge air cooler icing while still enabling fuel vapor purging when conditions permit.
Solution Approach 2:
The control system applies preliminary anti-action by detecting low ambient temperatures before purging operations and preemptively adjusting the first throttle valve positioning to prevent icing. The system anticipates the harmful effect of icing and takes preventive measures by maintaining adequate air flow through the charge air cooler even during purging operations in cold conditions.
4Measurement precision
If multiple throttle valves are controlled for precise torque management, then torque control precision improves, but system complexity increases
Solution Approach 1:
The torque control function is segmented between two throttle valves with distinct roles: the first throttle valve primarily controls air flow for torque management and purging operations, while the second throttle valve handles downstream air flow regulation and compensates for first valve positioning changes. This segmentation distributes the control complexity across multiple simple, well-defined functions rather than requiring one complex control mechanism.
Data Source
AI summary
An engine system includes: a first throttle valve; a turbocharger compressor disposed downstream of the first throttle valve; a charge air cooler disposed downstream of the turbocharger compressor; a second throttle valve located downstream of the turbocharger compressor; a purge inlet located downstream of the first throttle valve and configured to introduce fuel vapor from a fuel tank into intake air; and an engine control module configured to: maintain the first throttle valve in a fully open position; and selectively close the first throttle valve relative to the fully open position in response to receipt of a request to at least one of: purge fuel vapor from the fuel tank; and at least one of decrease and prevent icing of the charge air cooler.