Magnetic Levitation Control through the Introduction of Bogie Pitch Motion into a Control Law

The highly maneuverable fighter aircraft is exposed to unexpected pitch motion such as over-Nz (normal acceleration) and Nz-drop characteristics in transonic and supersonic flight conditions with moderate angle of attack. These characteristics not only degrade flying qualities by destabilizing the aircraft but also threaten flight safety by increasing the structural load. This article proposes an additional augmentation control in the incremental nonlinear dynamic inversion structure, which feeds back the error of pitch angular acceleration to mitigate unexpected pitch motion in slow down turn maneuver. We evaluate the stability, flying qualities, and robustness of the proposed control system by performing the frequency-domain linear analysis and the time-domain numerical simulations based on the mathematical model of advanced trainer aircraft. As a result of the evaluation, the additional augmentation control further improves flying qualities and deceleration performance of the aircraft by decreasing over-Nz and Nz-drop characteristics in high-Nz maneuvering in the transonic flight condition as well as ensuring the stability and robustness of the control system against the major uncertainty factors of the aircraft system compared to the existing transonic pitching moment compensation (TPMC) control in which the predefined scheduling for Nz feedback is used.

Download Full-text

Surgical Robot With Variable Remote Center of Motion Mechanism Using Flexible Structure

Journal of Mechanisms and Robotics ◽

10.1115/1.4039396 ◽

2018 ◽

Vol 10 (3) ◽

Author(s):

Sho Yoshida ◽

Takahiro Kanno ◽

Kenji Kawashima

Keyword(s):

Degrees Of Freedom ◽

Translational Motion ◽

Three Dimensional ◽

Flexible Structure ◽

Control Law ◽

Surgical Robots ◽

Pitch Motion ◽

Bending Radius ◽

Phantom Tissue ◽

Pneumatic Cylinders

Remote center of motion (RCM) mechanisms are often used in surgical robots for laparoscopic surgery. In this paper, a RCM mechanism for holding a robotic forceps that facilitates adjustment using a flexible structure is proposed. The flexible structure is designed and manufactured with polypropylene-like resin material using a three-dimensional (3D) printer. Super elastic NI-Ti rods are inserted in the structure to have elasticity for bending and have rigidity for twisting. The structure achieves pitch motion around the remote center with two pneumatic cylinders. One cylinder drives the position and the other cylinder controls the bending radius of the structure. Therefore, the location of the remote center can be variable. This allows easier adjustment of the remote center before or during operation. The holder robot including the mechanism has four degrees-of-freedom (DOFs) in total, consisting of the pitch, a rotation around yaw axis, a translation in the direction of forceps insertion and a rotation of the forceps. Pneumatic rotary actuators are used for rotations and a cylinder is used for the translational motion. The model of the flexible structure is derived experimentally to design a controller for the pitch motion. A pneumatically driven robotic forceps is mounted on the holder to construct a master–slave control system. Experimental results show that the proposed control law achieves the desired rotational pitch motion. We compare the holder with a rigid link RCM holder and confirm the robustness of the proposed holder for variable remote center. Finally, the effectiveness of the system is confirmed with suturing tasks using a phantom tissue.

Download Full-text

Passivity-Based Control Design for Magnetic Levitation System

Applied Sciences ◽

10.3390/app10072392 ◽

2020 ◽

Vol 10 (7) ◽

pp. 2392 ◽

Cited By ~ 2

Author(s):

Wang Yang ◽

Fanwei Meng ◽

Man Sun ◽

Kai Liu

Keyword(s):

Nonlinear Control ◽

Qualitative Method ◽

Magnetic Levitation ◽

Design Method ◽

Electromagnetic Levitation ◽

Design Tool ◽

Control Law ◽

Levitation System ◽

Magnetic Levitation System ◽

Passivity Based Control

The passivity-based control (PBC) is a new direction of nonlinear control, but the method is basically a qualitative method. A quantifiable design method in combination with PBC is provided in this paper. To solve the partial differential equation (PDE) for PBC, the nonlinear system must first be transformed into a Hamiltonian model. The PDE for the Hamiltonian system is then quantifiably solved with an electromagnetic levitation example. The resulting control law is presented and discussed. The proposed method provides a practical design tool for nonlinear control.

Download Full-text

Energy-Based Controller Design of Stochastic Magnetic Levitation System

Mathematical Problems in Engineering ◽

10.1155/2017/7838431 ◽

2017 ◽

Vol 2017 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Weiwei Sun ◽

Kaili Wang ◽

Congcong Nie ◽

Xuejun Xie

Keyword(s):

Hamiltonian Structure ◽

Controller Design ◽

Magnetic Levitation ◽

Lyapunov Theory ◽

Feedback Signal ◽

Control Law ◽

Stochastic Disturbance ◽

Levitation System ◽

Magnetic Levitation System ◽

Balance Relation

This paper investigates the control problem of magnetic levitation system, in which velocity feedback signal is influenced by stochastic disturbance. Firstly, single-degree-freedom magnetic levitation is regarded as an energy-transform action device. From the view of energy-balance relation, the magnetic levitation system is transformed into port-controlled Hamiltonian system model. Next, based on the Hamiltonian structure, the control law of magnetic levitation system is designed by applying Lyapunov theory. Finally, the simulation verifies the correctness of the proposed results.

Download Full-text

Application of non-linear control to a magnetic levitation system

International Journal of Mathematical Analysis ◽

10.12988/ijma.2017.710137 ◽

2017 ◽

Vol 11 (22) ◽

pp. 1055-1063

Author(s):

Rafael Antonio Acosta Rodriguez ◽

Octavio Jose Salcedo Parra ◽

Giovanny Mauricio Tarazona Bermudez

Keyword(s):

Nonlinear Model ◽

State Feedback ◽

Magnetic Levitation ◽

State Feedback Control ◽

Linear Control ◽

Control Law ◽

State Variables ◽

Levitation System ◽

Perturbation Vector ◽

Magnetic Levitation System

This paper evaluates the nonlinear control applied to a magnetic levitating plant, it is explained in detail the nonlinear model of the plant, the state variables, perturbation vector. A state feedback control was triggered by applying a state observer. Finally it was modeled under the control law found in the presence of disturbances.

Download Full-text

Synthesis of a Robust Nonlinear Control Law of a Magnetic Levitation System: Sliding Mode Control

2019 III International Conference on Control in Technical Systems (CTS) ◽

10.1109/cts48763.2019.8973366 ◽

2019 ◽

Author(s):

A. A. Kuz'menko

Keyword(s):

Sliding Mode Control ◽

Nonlinear Control ◽

Magnetic Levitation ◽

Sliding Mode ◽

Control Law ◽

Robust Nonlinear Control ◽

Mode Control ◽

Levitation System ◽

Magnetic Levitation System ◽

Nonlinear Control Law

Download Full-text

Robust Fuzzy Logic Stabilization with Disturbance Elimination

The Scientific World JOURNAL ◽

10.1155/2014/171597 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7

Author(s):

Kumeresan A. Danapalasingam

Keyword(s):

Fuzzy Logic ◽

Control System ◽

Fuzzy Logic Controller ◽

Magnetic Levitation ◽

Control Law ◽

Dynamic Feedback ◽

Model Uncertainties ◽

Levitation System ◽

Magnetic Levitation System ◽

Mathematical Derivation

A robust fuzzy logic controller is proposed for stabilization and disturbance rejection in nonlinear control systems of a particular type. The dynamic feedback controller is designed as a combination of a control law that compensates for nonlinear terms in a control system and a dynamic fuzzy logic controller that addresses unknown model uncertainties and an unmeasured disturbance. Since it is challenging to derive a highly accurate mathematical model, the proposed controller requires only nominal functions of a control system. In this paper, a mathematical derivation is carried out to prove that the controller is able to achieve asymptotic stability by processing state measurements. Robustness here refers to the ability of the controller to asymptotically steer the state vector towards the origin in the presence of model uncertainties and a disturbance input. Simulation results of the robust fuzzy logic controller application in a magnetic levitation system demonstrate the feasibility of the control design.

Download Full-text

Control of a MIMO Magnetic Levitation System using Exponential Control Barrier Function

10.48011/asba.v2i1.1209 ◽

2020 ◽

Author(s):

Caio I. G. Chinelato ◽

Bruno A. Angélico

Keyword(s):

Feedback Linearization ◽

Control Structure ◽

Magnetic Levitation ◽

Metal Plate ◽

Open Loop ◽

Control Law ◽

Barrier Functions ◽

Levitation System ◽

Safety Constraints ◽

Magnetic Levitation System

This work presents the control of a magnetic levitation system. The system is constituted by a Y shape metal plate that must be levitated by electromagnetic attractive forces. The system is nonlinear, open loop unstable and Multiple-Input/Multiple-Output (MIMO), whose inputs are represented by attractive forces generated from three electromagnets and outputs are represented by three plate positions. The proposed control structure uses Quadratic Programming (QP) to combine performance/stability objectives, represented by an arbitrary nominal control law, and safety constraints, represented by Control Barrier Functions (CBFs). The arbitrary nominal control law applied is determined by feedback linearization. Multiple safety constraints with relative-degree greater than one were applied. One way to deal with this is to use Exponential Control Barrier Functions (ECBFs). The results of this control structure applied to the magnetic levitation system are obtained through numerical simulations and indicate that performance/stability objectives are reached and safety constraints are respected.

Download Full-text