Engine Governor PID Control Integral Windup Prevention
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Solution Overview
Problem
Existing engine speed control systems fail to effectively suppress the reduction amount of actual engine speed when it exceeds the target speed due to external factors, leading to inefficient convergence on the target speed after such factors are canceled.
Innovation Solution
The engine speed control unit employs a PID control mechanism with enhanced P and I component calculations, including windup prevention and dynamic gain adjustments, to manage the speed difference and external influences, ensuring rapid convergence by doubling the P component and resetting the I component when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the integral control value is continuously integrated when actual engine speed is lower than target engine speed, then the integral control value increases to eliminate speed difference, but the integral control value becomes too large causing evil influence
Solution Approach 1:
The patent applies preliminary anti-action by detecting when actual engine speed exceeds target engine speed by a predetermined amount and forcibly resetting the integral control value to prevent it from becoming excessively large. This preemptive measure counteracts the potential harmful effect of integral windup before it occurs, ensuring stable control without oscillation or overshoot.
2Stability of the object's composition
If the integral control value is reset when actual engine speed exceeds target engine speed, then the reduction amount of actual engine speed is suppressed, but response time may be affected
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the reset threshold of the integral control value based on the magnitude of speed excess. When actual engine speed exceeds target engine speed by more than a predetermined amount, the integral control value is reset; otherwise, it continues normal integration. This adaptive parameter adjustment maintains stability while preserving necessary response capability.
3Object-generated harmful factors
If windup prevention is implemented by stopping integration when target rack position reaches limits, then integral control value is prevented from becoming too large, but calculation time is required to determine when to stop
Solution Approach 1:
The patent extracts the windup prevention function from the general PID control loop by implementing a separate detection and reset mechanism specifically for the integral control value. This dedicated extraction allows the system to monitor and correct integral windup independently, preventing harmful effects while minimizing impact on overall control calculation efficiency.
Data Source
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AI summary
An engine governor (10) comprising a fuel supply calculation means for calculating the amount of fuel supplied to an engine (3) on the basis of the difference in speed between the target engine speed (Nset) and the actual engine speed (Nact), and a fuel supply adjustment means for adjusting the amount of fuel supplied to the engine (3) on the basis of the calculation results from the fuel supply calculation means, wherein in cases when the difference in speed between the target engine speed (Nset) and the low idle engine speed (Nlow) is equal to or less than a first predetermined speed, the difference in speed between the actual engine speed (Nact) and the target engine speed (Nset) is equal to or greater than a second predetermined speed, and the calculation results from the fuel supply calculation means are equal to or less than the minimum value of the actual engine speed (Nact), the P gain is set at a value equal to or greater than the normal value, and additionally in cases where the I component is a negative value, the I component is set to zero.