IJFP-2018-0015 - Robust Control Design for an Inlet Metering Velocity Control System of a Linear Hydraulic Actuator

In this work, a hydraulic system in which the hydraulic motor velocity is controlled using a variable speed pump. A comprehensive dynamic model was created and the performance and stability of the open loop system were assessed. Then, PID and loop shaping H-infinity controllers were designed with the aim of improving the system performance. The multiplicative uncertainty, that is associated with uncertain parameters in the speed controlled velocity control system, was studied. Two parameters were introduced in the uncertainty analysis; the leakage coefficient and the viscous friction coefficient. The requirements of the system performance were defined in the frequency domain that was used to determine the robustness of the closed-loop velocity control system. The results showed that the proposed open loop hydraulic system is stable. It was also shown that using feedback control greatly improves the system performance. The performance of the nominal system, based on the obtained results, with H∞ controller was found to be better than that of the system with PID controller. It was found that the H∞ controller has the advantages of having robust performance by considering the uncertainty in addition to not having an integral control as in the PID control system. In addition, it was found that the system with the PID controller did not achieve robust performance.

“…( 14) and Eq. ( 15) respectively ( 14) (15) The next stage is to define the system's uncertainty ant its modeling.…”

Section: Stability Analysismentioning

confidence: 99%

“…When the controller design is developed based on both performance and uncertainty, the structured matrix, , is considered [15]. This matrix is defined as shown in Eq.…”

Section: Figure 2: the Block Diagram Of The Feedback Control System With The Weightsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

H∞ Loop Shaping Control Design of the Rotational Velocity of a Hydraulic Motor

2021

“…Many studies have been conducted on the hydrostatic transmissions and improving stability and performance of the hydrostatic transmission. Uncertainty of the inlet metering velocity control system was proposed in [4]. In that work, PID and H∞ were designed.…”

Section: Introductionmentioning

confidence: 99%

A Robust Controller Design for an Inlet Throttling Speed Control System for a Rotary Actuator

2024

In this paper, a novel flow control strategy which is the inlet throttled pump was used to design an angular velocity control system for rotary actuator. Inlet throttled systems have good performance in addition to their high efficiency compared to traditional valve-controlled systems. The flow in the proposed system is adjusted by a valve that is positioned at the pump inlet with the purpose of reducing the energy loses across the valve. This regulated flow is used then to control the actuator angular velocity. The system was modeled and the open loop stability and performance were studied. In order to improve the system performance, proportional-integralderivative (PID) and H-infinity controllers have been designed. The multiplicative uncertainty was analyzed to assess the robustness of the feedback control system where six parameters were considered uncertain within a range of +10%. The robust stability and performance requirements of the closed-loop angular velocity control system were assessed in the frequency domain. The time response of the system showed that the system is stable with both PID and H-infinity controllers. The PID controller have the advantages of simplicity and high response speed while the H∞ controller provides better nominal performance, robustness, and stability. The H∞ controller can handle parametric uncertainty without requiring pure integral term which is a significant advantage over the PID controller. On the other hand, the PID controller falls short of achieving robust performance, making it less suitable for systems that require high levels of performance and robustness. In summary, the H∞ controller is a more comprehensive solution for ensuring the best performance of a system. In contrast, the PID controller may be more suitable for systems with less stringent performance requirements.

“…The system with the designed controller showed reasonable response under the parametric uncertainty conditions. PID and H-infinity controller were designed in [20] for a hydraulic actuator system. The results showed that the system with H-infinity controller performs better than the PID controller.…”

Section: Introductionmentioning

confidence: 99%

Analytical Position Control System of a Linear Hydraulic Actuator Used in Aircraft Applications

2023

This paper proposes a novel control technique for motion control of a linear hydraulic actuator, in which actuator reference position and velocity profiles are generated analytically. The proposed algorithm parameterizes an eight-term exponential function based on initial, middle, and final boundary conditions. Nominal and off-nominal disturbance forces applied against the actuator are completely included to shape the desired system reference. This new scheme can create the reference pump rotational speed required to accurately control the presented system with no closed-loop commands and with excellent performance characteristics. Moreover, unlike the traditional hydraulic actuator control algorithms, the presented methodology is able to successfully respond to a wide range of disturbance forces while satisfying steady state conditions. The results showed that, the proposed controller steers the system to the steady state desired value within about 0.1 second only and with zero percent overshoot in terms of the reference input and about 2 percent for the disturbance input. Numerical results using the Monte-Carlo simulation method confirmed the effectiveness and the robustness of the new algorithm despite wide range of disturbance forces.