Dynamometer Control Device Vibration Suppression
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Solution Overview
Problem
Conventional dynamometer systems with rocking type dynamometers face instability and reduced control responsiveness due to natural vibration, leading to unwanted torque fluctuations and electrode hunting or divergence, which are difficult to suppress effectively.
Innovation Solution
A control device with a natural-vibration suppression means, including a differential compensator and subtractor, corrects the output signal from the load cell to suppress natural vibration, eliminating unnecessary torque fluctuations without requiring an acceleration sensor, and further incorporates vibration output calculation, delay compensators, and proportional elements to enhance stability and responsiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional load cell detection is used in rocking type dynamometer, then torque measurement is achieved, but natural vibration causes unstable control and electrode hunting
Solution Approach 1:
The patent implements feedback control by detecting the natural vibration state through load cell output fluctuations and actively suppressing it through control signals to the exciter. The control system continuously monitors the vibration state and adjusts the suppression force accordingly, creating a closed-loop feedback mechanism that stabilizes the rocking piece while maintaining accurate torque measurement.
Solution Approach 2:
The patent converts the harmful natural vibration into a beneficial control opportunity by using the vibration detection itself as the basis for suppression. The load cell output, which contains vibration noise, is processed to extract vibration state information, and this information is then used to generate counteracting control signals that eliminate the harmful effects of the vibration while preserving the measurement capability.
2Reliability
If acceleration sensor is added to suppress natural vibration, then control stability improves, but device complexity increases
Solution Approach 1:
The patent makes the load cell serve multiple functions: it simultaneously performs torque measurement and natural vibration detection. By processing the load cell output signal to extract both torque information and vibration state information, the system eliminates the need for separate acceleration sensors while maintaining vibration suppression capability, thus reducing device complexity.
Solution Approach 2:
The patent merges the torque measurement function and vibration detection function into a single load cell system. The load cell output signal is processed through signal processing circuits that separate and utilize both torque components and vibration components from the same sensor, combining multiple functions into one sensor system to reduce overall device complexity.
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
The solution provides a stable and highly responsive control of the dynamometer system by effectively suppressing natural vibration, resulting in a stable output signal from the load cell without the need for an acceleration sensor, thereby improving control stability and responsiveness.
Implementation Method 1
a differential compensator (for example, a differential compensator 71 to be described later) for performing differential calculation on the output signal (LC_det) from the load cell
Implementation Method 2
a subtractor (for example, a subtractor 72 to be described later) for correcting the main signal by subtracting an output signal of the differential compensator from the main signal
Implementation Method 3
a control input signal into such a controlled object is corrected by the differential compensator, and as a result, damping can be provided to the controlled object so as to suppress the natural vibration of the rocking piece
Data Source
AI summary
Provided is a dynamometer system control device capable of stable and highly responsive control. This dynamometer system control device is provided with a torque control device which outputs a torque command signal on the basis of an output signal (LC_det) of a load cell, and with a characteristic vibration suppression circuit which corrects the torque command signal to suppress the characteristic vibration of an oscillator and which inputs said signal to an inverter as a control input signal. The circuit is provided with a differential compensator which performs a differentiation operation on a load cell approximation signal (Pmdl_det) calculated using an approximation equation in a secondary delay canonical form in a vibration output calculation unit, and with a subtractor which corrects the torque command signal by subtracting the output signal from the compensator from the torque command signal (Tdy_ref).