Solenoid Valve Controller Ending-of-Activation Phase
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Solution Overview
Problem
Existing control systems for solenoid injector valves in internal combustion engines face challenges in minimizing shot-to-shot variation and current ripple, leading to inaccuracies and repeatability issues due to inherent statistical variations and non-ideal power stage delays, which cannot be fully compensated by adjusting control signal durations.
Innovation Solution
A valve controller with an application-specific integrated circuit (ASIC) and state machine that introduces an ending-of-activation phase with reduced current ripple, achieved by increasing switching frequency and limiting the duration of this phase, allowing for better control over the solenoid valve activation and deactivation phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the switching frequency is increased during the ending-of-activation phase to reduce current ripple, then the jitter and shot-to-shot variation are reduced, but the power loss increases
Solution Approach 1:
The patent applies periodic switching action during the ending-of-activation phase to reduce current ripple. By increasing the switching frequency during this specific phase, the current ripple is minimized, which reduces jitter and improves activation timing precision. The periodic nature of the switching allows for controlled reduction of ripple while managing power loss through phase-specific application.
Solution Approach 2:
The patent changes the switching frequency parameter during the ending-of-activation phase. By dynamically adjusting the switching frequency to be higher during this phase compared to other phases, the system achieves reduced current ripple and improved timing precision. This parameter change is localized to specific phases, allowing optimization of precision without excessive overall power loss.
2Loss of energy
If the duration of the ending-of-activation phase is limited to reduce power loss, then the energy consumption is reduced, but the current ripple reduction effect is diminished
Solution Approach 1:
The patent applies partial action by implementing the high-frequency switching only during the ending-of-activation phase rather than continuously throughout all phases. This limited application duration reduces overall energy consumption while still achieving sufficient current ripple reduction to improve timing precision. The phase-specific application balances energy efficiency with performance requirements.
Solution Approach 2:
The ending-of-activation phase uses periodic high-frequency switching action for a limited duration. This time-bound periodic action allows the system to achieve current ripple reduction during the critical deactivation period while minimizing energy consumption by not maintaining high-frequency switching during other phases where it is less critical.
3Loss of energy
If the hold phase current level is reduced to manage power loss, then the energy consumption during hold phase is reduced, but the shot-to-shot variation of current decay increases
Solution Approach 1:
The patent changes the current level parameter during the hold phase to a reduced level that still maintains adequate valve actuation while reducing power loss. This parameter optimization allows the system to operate at lower current during the extended hold phase, managing energy consumption while maintaining sufficient magnetic force for reliable valve operation.
Solution Approach 2:
The hold phase maintains continuous current flow at a reduced level to keep the valve reliably actuated throughout the required duration. This continuous action at optimized current levels ensures consistent valve operation while managing power consumption, preventing both excessive energy loss and insufficient actuation force.
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
This approach reduces jitter and improves the accuracy and repeatability of solenoid valve operations by minimizing current ripple during the ending-of-activation phase, maintaining power loss within acceptable limits and enhancing the overall control precision.
Implementation Method 1
Solenoid actuators for (direct) injection valves and intake valves are operated by controlling the current through its coil (which behaves as a resistive-inductive load)
Data Source
AI summary
A valve controller and method for controlling a valve having a solenoid are disclosed, including receiving a least one input signal, detecting a first edge of the at least one signal and in response to the detection activating the valve. Activating the valve includes activating the valve in a rise-to-peak phase during which the valve is opened, a hold phase following the rise-to-peak phase during which the valve remains open and a current level of the valve is less than a current level of the valve during the rise-to-peak phase, and an ending-of-activation phase following the hold phase during which current ripple in the valve is less than the current ripple in the valve during the hold phase.