Development and Control of Electro-hydraulic Fully Flexible Valve Actuation System for Diesel Combustion Research

Unstable vibrations (i.e., chatter) onset is one of the main limits to productivity in deep boring bar processes. Active damping systems allow to increase machining stability in different configurations (i.e., tool setup), without requiring cutting system dynamic characterization. Design of an active boring bar involves the development of monitoring system (sensors), actuation system and control logic. While several control logics were evaluated and discussed, few design solutions were presented in the literature, focusing only on building prototypes to demonstrate control logic effectiveness. In the presented work, a deep analysis of the main issues and requirements related to active boring design was carried out and a systematic approach to tackle all the critical aspects was developed. The results of the proposed method are: (i) optimal actuators positioning able to damp vibration along two directions; (ii) preload system design guaranteeing the correct actuator preloading for the operating conditions; (iii) covers design to protect actuators and ensure the dynamic and static equivalence between active and standard boring bar. Following this approach, an active boring bar was designed, realized and tested. The results prove the required equivalence between active and original boring bar and assess the damping effect.

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Electro-pneumatic variable valve actuation system for camless engine: Part II-fuel consumption improvement through un-throttled operation

Energy ◽

10.1016/j.energy.2019.116741 ◽

2020 ◽

Vol 193 ◽

pp. 116741

Author(s):

Srinibas Tripathy ◽

Abhimanyu Das ◽

Dhananjay Kumar Srivastava

Keyword(s):

Fuel Consumption ◽

Variable Valve Actuation ◽

Actuation System ◽

Engine Part ◽

Camless Engine ◽

Variable Valve ◽

Fuel Consumption Improvement ◽

Valve Actuation

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Design and Control of a Compact and Flexible Pneumatic Artificial Muscle Actuation System: Part Two—Robust Control

ASME 2011 Dynamic Systems and Control Conference and Bath/ASME Symposium on Fluid Power and Motion Control, Volume 1 ◽

10.1115/dscc2011-6068 ◽

2011 ◽

Author(s):

Sai-Kit Wu ◽

Garrett Waycaster ◽

Tad Driver ◽

Xiangrong Shen

Keyword(s):

Robust Control ◽

Nonlinear Model ◽

Sliding Mode ◽

Artificial Muscle ◽

Control Approach ◽

Actuation System ◽

Highly Nonlinear ◽

Pressure Dynamics ◽

System Part ◽

And Control

A robust control approach is presented in this part of the paper, which provides an effective servo control for the novel PAM actuation system presented in Part I. Control of PAM actuation systems is generally considered as a challenging topic, due primarily to the highly nonlinear nature of such system. With the introduction of new design features (variable-radius pulley and spring-return mechanism), the new PAM actuation system involves additional nonlinearities (e.g. the nonlinear relationship between the joint angle and the actuator length), which further increasing the control difficulty. To address this issue, a nonlinear model based approach is developed. The foundation of this approach is a dynamic model of the new actuation system, which covers the major nonlinear processes in the system, including the load dynamics, force generation from internal pressure, pressure dynamics, and mass flow regulation with servo valve. Based on this nonlinear model, a sliding mode control approach is developed, which provides a robust control of the joint motion in the presence of model uncertainties and disturbances. This control was implemented on an experimental setup, and the effectiveness of the controller demonstrated by sinusoidal tracking at different frequencies.

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