Engine Clutch State Determination Using Actuator Pressure and Stroke
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Solution Overview
Problem
Existing methods for determining the connection state of an engine clutch in hybrid vehicles are inaccurate, often misjudging the clutch as locked up when it is open or vice versa, due to reliance on transfer torque and speed difference alone, leading to potential vehicle safety issues.
Innovation Solution
A method that uses actuator pressure, actuator stroke, and speed difference between engine and motor RPMs to accurately classify the connection state of the engine clutch, involving operations such as stroke sensing, pressure comparing, torque comparing, and RPM comparing to determine open, slip, and lock up states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If transfer torque and speed difference are used to determine clutch state, then the determination process is simple, but the accuracy of clutch state classification deteriorates
Solution Approach 1:
The patent introduces actuator pressure and actuator stroke as additional parameters to the existing transfer torque and speed difference measurements. By monitoring multiple parameters simultaneously (pressure, stroke, torque, RPM difference), the system achieves more accurate clutch state classification without excessive complexity, as each parameter provides complementary information about the clutch state.
Solution Approach 2:
The patent adds a new dimension of measurement by incorporating actuator pressure and stroke information alongside the existing torque and speed measurements. This multi-dimensional approach allows the controller to distinguish between slip state and lock-up state more reliably, transforming a two-parameter determination into a four-parameter comprehensive assessment.
2Measurement precision
If actuator pressure, actuator stroke, transfer torque, and speed difference are used together, then the accuracy of clutch state determination is improved, but the device complexity increases
Solution Approach 1:
The patent segments the clutch state determination into distinct operational phases: open state determination (using stroke increase + pressure exceedance + torque comparison), slip state determination (using RPM difference comparison), and lock-up state determination (using RPM difference comparison). Each state has specific determination criteria, preventing the need to process all parameters simultaneously for every state assessment.
Solution Approach 2:
The system continuously monitors actuator pressure, stroke, transfer torque, and RPM difference, using feedback loops to update clutch state determination in real-time. The controller adjusts its assessment based on changing parameter values, allowing accurate state classification while managing computational complexity through iterative refinement rather than exhaustive analysis.
Data Source
AI summary
A method for determining a connection state of an engine clutch includes: a stroke sensing operation of sensing, by a controller, a change of an actuator stroke of the engine clutch; a first pressure comparing operation of determining whether or not an actuator pressure of the engine clutch exceeds a first set pressure and is then changed to below the first set pressure when the actuator stroke is increased; a torque comparing operation of comparing transfer a torque of the engine clutch with a set torque when the actuator pressure exceeds the first set pressure and is then operated to below the first set pressure; and an open determining operation of determining that the engine clutch is in an open state when the transfer torque of the engine clutch is the set torque or less.