Reducing the Vibrations of an Unbalanced Rotary Engine by Active Force Control

In this paper, a 2-degree of freedom dynamic model of an unbalanced rotary engine is designed, in a manner that has the effect of modal coupling. After designing the dynamic model in order to reduce the vibrations generated due to the unbalancing mass and modal coupling, the active force control (AFC) method is implemented along with a conventional proportional integral derivative (PID) controller with linear actuators, meaning that the AFC loop is applied as a supplement to the conventional PID controller. The obtained results show that, when the AFC loop was engaged with the PID controller, the vibrations were reduced to nearly zero in both aspects of frequency and amplitude when compared to the case in which only a PID controller was operating in the control system.

Section: Control Strategy and Its Simulationmentioning

confidence: 99%

Designing a 2-Degree of Freedom Model of an Unbalanced Engine and Reducing its Vibrations by Active Control

Mohebbi¹,

Hashemi²

2017

“…This method can reject very large disturbances. The PID controller has been discussed in the literature (Mohebbi & Hashemi, 2016;Mohebbi & Hashemi, 2017). However, this has a weakness, which is the presence of new disturbance known after measuring output.…”

Section: Introductionmentioning

confidence: 99%

Inverted Decoupling 2DoF Internal Model Control for Mimo Processes

Juwari¹,

Azizah²,

Handogo³

et al. 2019

In general, the multiple-input-multiple-output (MIMO) system is the main method of process control in industry. However, the interaction between variables in the process is a challenge when designing controllers for the system. Strong interaction worsens system performance. Inverted decoupling plays an important role in reducing interaction in the process. Internal model control (IMC) is the controller used in this research. A one degree of freedom (1DoF) IMC controller is only able to provide a good response to set-point tracking, and has a slow response to disturbance rejection. Therefore, a controller that has a good response to set-point tracking and disturbance rejection is a two degrees of freedom (2DoF) IMC. The tuning method uses maximum peak gain margin (Mp-GM) stability criteria based on the uncertainty model. In this study, a reduction in interaction was realized by the addition of inverted decoupling to the 2DoF IMC control scheme. The Wardle & Wood and Wood & Berry column distillation models are given as illustrative examples to demonstrate the performance of the inverted decoupling 2DoF IMC control scheme. A comparison is made of the IAE values of 1DoF IMC, 2DoF IMC, decoupling 2DoF IMC, and inverted decoupling 2DoF IMC, with inverted decoupling 2DoF IMC showing the lowest IAE value.

“…Active vibration control methods have proposed by researchers to attenuate vibration response occurred in mechanical systems. Mohebbi and Hashemi (2016) proposed an active vibration control technique for reducing the vibration response of an unbalanced rotary engine. In his study, the unbalanced rotary engine was modeled by a one-degree of freedom vibration system.…”

mentioning

confidence: 99%

Analysis of the Static Behavior of a New Landing Gear Model based on a Four-bar Linkage Mechanism

Son¹,

Adipta²,

Bur³

2019

A landing gear model using a four-bar linkage mechanism is proposed in this study. The simulation study was conducted to evaluate the effect of the link dimension variation and coil spring constant on the equivalent stiffness and static deflection of the landing gear. The simulation results show that increasing the landing gear dimension affects the static deflection of the landing gear. However, the linear stiffness of the landing gear system is not much affected by the landing gear dimension variation. Furthermore, the landing gear stiffness characteristic is nonlinear for large landing gear displacement.