Dynamometer Control Gain via Shaft Torque Resonance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing engine bench systems require time-consuming preliminary experiments and high computational loads to determine the relationship between shaft torque and mechanical resonance frequency, making them inconvenient and inefficient for testing.
Innovation Solution
A method that involves executing speed control of the dynamometer while the engine is in a non-ignition state, acquiring shaft torque detection signals during a predetermined speed range, analyzing the frequency of the strongest signal to determine the resonance frequency, and using this frequency to set control gains for the dynamometer control device, allowing for simple preliminary experiments and reduced computational load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gain schedule is performed using a map or table defining the relationship between shaft torque and mechanical resonance frequency, then resonance suppression is improved, but preliminary experiment time and preparation work increase
Solution Approach 1:
The system automatically identifies its own resonance frequency by utilizing the natural pulsating torque generated during engine operation. The resonance frequency identification unit detects the resonance frequency directly from the engine's own torque fluctuations without requiring external excitation or preliminary experiments, making the system self-diagnosing and self-configuring.
Solution Approach 2:
The system continuously monitors shaft torque fluctuations and uses feedback from the resonance frequency identification unit to dynamically adjust the gain schedule. The detected resonance frequency is fed back to update the control parameters in real-time, ensuring accurate resonance suppression without requiring pre-defined maps or tables.
2Reliability
If gain schedule is performed using a map or table defining the relationship between shaft torque and mechanical resonance frequency, then resonance suppression is improved, but preparation work and convenience worsen
Solution Approach 1:
The system automatically identifies its own resonance frequency by utilizing the natural pulsating torque generated during engine operation. The resonance frequency identification unit detects the resonance frequency directly from the engine's own torque fluctuations without requiring external excitation or preliminary experiments, making the system self-diagnosing and self-configuring.
Solution Approach 2:
The system changes the operational parameters by using the engine's natural pulsating torque characteristics at different revolution speeds to identify resonance frequency. Instead of requiring manual construction of torque-frequency maps, the system automatically extracts resonance information from the engine's own operational parameters.
3Reliability
If mechanical resonance frequency is calculated and control gain is determined every control cycle, then resonance suppression is improved, but computational load increases
Solution Approach 1:
The resonance frequency is identified in advance during engine operation or idle periods, and this pre-identified frequency is stored for use in subsequent control cycles. Instead of calculating resonance frequency every control cycle, the system performs the identification action beforehand and reuses the result, significantly reducing computational load during active control.
Solution Approach 2:
The system dynamically adjusts the resonance suppression control by updating the gain schedule based on the pre-identified resonance frequency and current operating conditions. The control gain is modified in real-time based on the stored resonance frequency information and current shaft torque, achieving adaptive control without continuous resonance frequency calculation.
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 enables effective resonance suppression in the engine bench system with minimal experimental effort and computational load, ensuring efficient testing by defining the control gain using a resonance frequency determined through a straightforward analysis.
Implementation Method 1
a shaft torque sensor (for example, the shaft torque sensor 61 described later) which generates a shaft torque detection signal according to shaft torque generated at the coupling shaft
Implementation Method 2
the mechanical resonance frequency which varies according to load as mentioned above is sequentially calculated, and gain schedule is performed so as to become a control gain according to the calculated mechanical resonance frequency
Data Source
AI summary
This method for controlling an engine bench system is provided with: a speed control step in which speed control of a dynamometer is executed while an engine is maintained in a non-ignition state, and in which the speed control is ended when the rotational speed of the dynamometer has increased to a prescribed speed; a measuring step in which a shaft torque detection signal is acquired during a period from when, as a result of inertia, the rotational speed of the dynamometer is a prescribed measuring start speed until said rotational speed reaches a prescribed measuring end speed; a frequency analyzing step in which the frequency of the signal having the strongest intensity, from among the shaft torque detection signals acquired in the measuring step, is acquired as a resonant frequency; a design step in which a control gain of a dynamometer control device is determined using the acquired resonant frequency.