Skip Fire Engine Control for Power Take-Off Torque Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Utility vehicles with power take-off implements often operate at idle or low torque levels, leading to poor fuel efficiency and emissions characteristics, and present challenges in determining when to implement skip fire engine control effectively.
Innovation Solution
Engine controllers that detect the engagement or disengagement of power take-off units and adjust engine operation modes between skip fire and all cylinder modes based on torque requests, emissions levels, and exhaust gas temperatures to optimize fuel efficiency and emissions management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the engine operates at idle or low torque levels with power take-off implements, then the implement can be used while the vehicle is stopped or moving slowly, but fuel efficiency and emissions characteristics deteriorate
Solution Approach 1:
The engine dynamically transitions between skip fire mode and all-cylinder mode based on real-time detection of PTO engagement status and torque requests. The controller monitors trigger actions (clutch engagement, control stick movement, throttle actuation) and adjusts the firing fraction accordingly, allowing the engine to adapt its operation to match actual power demands while maintaining implement operability during stopped or slow vehicle conditions
2Adaptability or versatility
If the engine operates at idle or low torque levels with power take-off implements, then the implement can be used while the vehicle is stopped or moving slowly, but emissions characteristics deteriorate
Solution Approach 1:
The engine dynamically transitions between skip fire mode and all-cylinder mode based on real-time detection of PTO engagement status and torque requests. The controller monitors trigger actions (clutch engagement, control stick movement, throttle actuation) and adjusts the firing fraction accordingly, allowing the engine to adapt its operation to match actual power demands while maintaining implement operability during stopped or slow vehicle conditions
Solution Approach 2:
The engine control system changes operational parameters by transitioning between different firing fractions (skip fire vs. all-cylinder modes). This parameter change optimizes the balance between maintaining implement operability and reducing emissions, allowing the engine to operate more efficiently during low-load conditions while still providing necessary power when the PTO is engaged
3Use of energy by moving object
If the engine transitions out of skip fire mode when PTO is engaged and torque request exceeds threshold, then fuel efficiency improves, but response time to provide required power may be delayed
Solution Approach 1:
The control system continuously monitors PTO engagement status through multiple trigger actions (clutch position, control stick position, throttle position) and real-time torque requests. This feedback mechanism allows the engine to detect when PTO engagement occurs and when torque demands exceed the skip fire threshold, enabling timely transitions from skip fire to all-cylinder mode to ensure adequate power response while maintaining fuel efficiency during appropriate operating conditions
4Use of energy by moving object
If the engine transitions to skip fire mode when PTO is disengaged and torque request is below threshold, then fuel efficiency improves, but exhaust gas temperature may drop below optimal levels
Solution Approach 1:
The engine control system changes operational parameters by transitioning between different firing fractions (skip fire vs. all-cylinder modes). This parameter change optimizes the balance between maintaining implement operability and reducing emissions, allowing the engine to operate more efficiently during low-load conditions while still providing necessary power when the PTO is engaged
Data Source
AI summary
Engine controllers and control schemes that facilitate skip fire engine operation in conjunction with use power take-off devices are described. In one aspect, a skip fire mode is exited when the power take-off unit is engaged and the current torque request exceeds a torque threshold. In some embodiments, the exit is delayed when the temperature of an after treatment system is below a designated temperature threshold. In another aspect, the engine transitions to the skip fire mode when the power take-off unit disengages. In some embodiments, exiting is conditioned on the current torque request being less than a torque threshold. In some embodiments, the transition is made immediately, whereas in others the transition only occurs when the power take-off unit is not reengaged for a period of time or is further conditioned on determining that the power take-off unit is likely to remain disengaged for the period of time.