Engine Control Device Clutch Feedback Adjustment
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Solution Overview
Problem
Existing internal combustion engine control devices face issues with engine stop occurrences during shift operations, particularly when a vehicle travels downhill in creep mode, leading to increased deviation between idle and actual engine rotational speeds and excessive negative feedback control corrections.
Innovation Solution
The control device adjusts the lower limit value of the feedback control amount based on the clutch engagement state, reducing the absolute value of the lower limit value when the clutch is fully engaged to prevent excessive negative corrections and engine stop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If feedback control of engine rotational speed to idle rotational speed is performed during creep driving, then engine rotational speed can be maintained at idle speed, but engine stop occurs during shift operation due to excessive negative feedback control amount
Solution Approach 1:
The feedback control amount lower limit is dynamically adjusted based on clutch engagement state. When the clutch is fully engaged, the lower limit is set to a larger value (less negative), preventing excessive negative corrections during shift operations. When the clutch is not fully engaged, the conventional lower limit applies, maintaining effective idle speed control during normal creep driving.
Solution Approach 2:
The invention changes the parameter of feedback control amount lower limit based on clutch engagement state. By detecting whether the clutch is fully engaged or not, the system switches between different lower limit values, optimizing the feedback control behavior for each operational state to prevent engine stop during shifts while maintaining idle speed control during normal operation.
2Measurement precision
If feedback control continuously corrects engine rotational speed during downhill creep driving, then idle speed maintenance is achieved, but deviation between idle rotational speed and actual engine rotational speed increases continuously
Solution Approach 1:
The feedback control system dynamically adjusts the lower limit of correction amount based on clutch state. During downhill creep driving with fully engaged clutch, the increased lower limit prevents continuous negative corrections that would otherwise accumulate, thereby maintaining control accuracy and stability simultaneously.
Solution Approach 2:
By pre-setting a larger lower limit value for the feedback control amount when clutch is fully engaged, the system anticipates and prevents the accumulation of excessive negative corrections before they can cause instability or engine stop during shift operations.
Data Source
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AI summary
The problem addressed by the present invention is to prevent the occurrence of engine stoppage even during a shifting operation in an internal combustion engine control device that is a so-called cooperative control device automatically controlling the internal combustion engine and a transmission, and that performs feedback control of the rotational frequency of the internal combustion engine with respect to the idling rotational frequency and when the vehicle is performing creep travel. The control device (5) is provided with a control means (6) that alters the lower limit value for the amount of feedback control in accordance with the engagement state of a clutch (3).