scholarly journals Non Linear Modelling and Control of Hydraulic Actuators

10.14311/354 ◽  
2002 ◽  
Vol 42 (3) ◽  
Author(s):  
B. Šulc ◽  
J. A. Jan
Keyword(s):  
Linear Models ◽  
Hydraulic Actuator ◽  
Friction Forces ◽  
Linear Modelling ◽  
Non Linear ◽  
Object Oriented Approach ◽  
Physical Laws ◽  
And Control ◽  
Nonlinear State ◽  
Very High

This paper deals with non-linear modelling and control of a differential hydraulic actuator. The nonlinear state space equations are derived from basic physical laws. They are more powerful than the transfer function in the case of linear models, and they allow the application of an object oriented approach in simulation programs. The effects of all friction forces (static, Coulomb and viscous) have been modelled, and many phenomena that are usually neglected are taken into account, e.g., the static term of friction, the leakage between the two chambers and external space. Proportional Differential (PD) and Fuzzy Logic Controllers (FLC) have been applied in order to make a comparison by means of simulation. Simulation is performed using Matlab/Simulink, and some of the results are compared graphically. FLC is tuned in a such way that it produces a constant control signal close to its maximum (or minimum), where possible. In the case of PD control the occurrence of peaks cannot be avoided. These peaks produce a very high velocity that oversteps the allowed values.

Real Time Loading Test Rig for Flight Control Actuators Under PHM Experimentation

2018 ◽  
Author(s):  
P. Chiavaroli ◽  
A. De Martin ◽  
G. Evangelista ◽  
G. Jacazio ◽  
M. Sorli
Keyword(s):  
Flight Control ◽  
Linear Models ◽  
Angular Position ◽  
Experimental Tests ◽  
Hydraulic Actuator ◽  
Loading Test ◽  
Pressure Transducers ◽  
Non Linear ◽  
Flight Controls ◽  
Servo Actuator

The article deals with the architecture, performance, and experimental tests of a test bench for servo-actuators used in flight controls. After the state of the art on the subject, the innovative architecture of the built bench is described, in which flight control actuator under test and load actuator are not in line but mounted perpendicularly. The model of the bench actuating systems is then presented, consisting of the servo-controlled hydraulic actuator, load cell, speed transducer, angular position transducer of the coupling and pressure transducers. For each of these components the nonlinear multi-physics mechatronic model is described, according to the adopted solutions. The adopted force control algorithm is discussed, showing the integrative compensation on the action line and proportional-derivative on the feedback, with speed feedforward. The experimental tests carried out on the bench under stalled conditions are also presented, whose results concerning time and frequency responses are compared with those obtained through the linearized and non-linear numerical model. Finally, the non-linear models of the flight control actuator under test, controlled in position, and of the loading servo-actuator of the bench are joined together, and the results of various simulations are described.

Non-linear modelling and control of semi-active suspensions with variable damping

2013 ◽  
Vol 51 (10) ◽  
pp. 1568-1587 ◽  
Author(s):  
Huang Chen ◽  
Chen Long ◽  
Chao-Chun Yuan ◽  
Hao-Bin Jiang
Keyword(s):  
Active Suspensions ◽  
Linear Modelling ◽  
Non Linear ◽  
Variable Damping ◽  
And Control

Dynamics and Control of Four Wheeled Differentially Steered UGVs

2014 ◽  
Author(s):  
Andrew Narvesen ◽  
Majura F. Selekwa
Keyword(s):  
Autonomous Navigation ◽  
Research Area ◽  
Control Parameters ◽  
Ground Vehicles ◽  
Friction Forces ◽  
Straight Line ◽  
Dynamics And Control ◽  
Left And Right ◽  
And Control ◽  
Very High

Autonomous navigation of ground vehicles is a growing research area. Skid steered wheeled ground vehicles are of interest because of the system’s relatively easy control parameters. Steered wheels require actuation and control for the steering and speed of the steered wheels while skid steering just requires actuation and control of the wheel speeds, usually just a left and right wheel speed. Four Wheeled differentially steered vehicles are built primarily for straight line motion since the instantaneous centers of zero velocities for the four wheels are always at infinity when there is no sliding in the wheels. When the vehicle has to negotiate a corner, it uses the differential velocities between sides to force the wheels to slide and perform the cornering maneuver. Maneuvering is difficult when the ground friction is very high because of undue stresses in the axle structure. This paper analyses the dynamics of such vehicles that relates the traction and skid friction forces and proposes a suitable control system. At this time, the paper is supported by simulation results while experimental work is still going on.

Actuarial graduation practice and generalised linear and non-linear models

1991 ◽  
Vol 118 (2) ◽  
pp. 295-312 ◽  
Author(s):  
A. E. Renshaw
Keyword(s):  
Linear Models ◽  
Considerable Effect ◽  
Life Tables ◽  
Modelling Framework ◽  
Linear Modelling ◽  
Non Linear

ABSTRACTIt is demonstrated how existing actuarial graduation practice, used in the construction of life tables, can be extended to considerable effect by formulating the techniques within the generalised linear and non-linear modelling framework.

G Optimal Design in Non linear Models to Increase Silicon Oxide Purity Levels and Electrical Conductivity

2018 ◽  
pp. 150-155
Author(s):  
Muklas Rivai
Keyword(s):  
Electrical Conductivity ◽  
Optimal Design ◽  
Linear Models ◽  
Silicon Oxide ◽  
Information Matrix ◽  
Relevant Information ◽  
Non Linear

Optimal design is a design which required in determining the points of variable factors that would be attempted to optimize the relevant information so that fulfilled the desired criteria. The optimal fulfillment criteria based on the information matrix of the selected model.

scholarly journals 2, 12, 117, 1959, 45171, 1170086, …: a Hilbert series for the QCD chiral Lagrangian

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Lukáš Gráf ◽  
Brian Henning ◽  
Xiaochuan Lu ◽  
Tom Melia ◽  
Hitoshi Murayama
Keyword(s):  
Hilbert Series ◽  
Charge Conjugation ◽  
External Fields ◽  
Dynkin Diagrams ◽  
Non Linear ◽  
Very High ◽  
Chiral Lagrangian

Abstract We apply Hilbert series techniques to the enumeration of operators in the mesonic QCD chiral Lagrangian. Existing Hilbert series technologies for non-linear realizations are extended to incorporate the external fields. The action of charge conjugation is addressed by folding the $$ \mathfrak{su}(n) $$ su n Dynkin diagrams, which we detail in an appendix that can be read separately as it has potential broader applications. New results include the enumeration of anomalous operators appearing in the chiral Lagrangian at order p8, as well as enumeration of CP-even, CP-odd, C-odd, and P-odd terms beginning from order p6. The method is extendable to very high orders, and we present results up to order p16.(The title sequence is the number of independent C-even and P-even operators in the mesonic QCD chiral Lagrangian with three light flavors of quarks, at chiral dimensions p2, p4, p6, …)

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