The authors' replies to the discussion on “The minimum-moment-of-error-squared criterion: a new performance criterion for servo mechanisms” and “The behaviour of a remote-position-control servo mechanism with hard-spring non-linear characteristics”

1954 ◽  
Vol 101 (83) ◽  
pp. 491-492
Author(s):  
J.H. Westcott ◽  
J.C. West ◽  
P.N. Nikiforuk
Keyword(s):  
Position Control ◽  
Performance Criterion ◽  
Criterion A ◽  
Servo Mechanism ◽  
Non Linear ◽  
Minimum Moment

Optimal strategies for a non-linear premium-reserve model in a competitive insurance market

2016 ◽  
Vol 11 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Athanasios A. Pantelous ◽  
Eudokia Passalidou
Keyword(s):  
Linear Models ◽  
Quadratic Function ◽  
Optimal Strategies ◽  
Mean Value ◽  
Performance Criterion ◽  
The State ◽  
Numerical Application ◽  
Income Insurance ◽  
Non Linear ◽  
Quadratic Performance

AbstractThe calculation of a fair premium is always a challenging topic in the real-world insurance applications. In this paper, a non-linear premium-reserve (P-R) model is presented and the premium is derived by minimising a quadratic performance criterion. The reserve is a stochastic equation, which includes an additive random non-linear function of the state, premium and not necessarily Gaussian noise, which is, however, independently distributed in time, provided only that the mean value and the covariance of the random function is 0 and a quadratic function of the state, premium and other parameters, respectively. In this quadratic representation of the covariance function, new parameters are implemented and enriched further by the previous linear models, such as the income insurance elasticity of demand, the number of insured and the inflation in addition to the company’s reputation. The quadratic utility function concerns the present value of the reserve. Interestingly, for the very first time, the derived optimal premium in a competitive market environment is also dependent on the company’s reserve among the other parameters. Finally, a numerical application illustrates the main findings of the paper.

Electrostatic Suspension System for Gyroscopes with Minimum Electrical Disturbing Torque via Non-Linear Pre-Compensation

1996 ◽  
Vol 210 (2) ◽  
pp. 123-127 ◽  
Author(s):  
W Q Yang
Keyword(s):  
Control System ◽  
Steady State ◽  
Position Control ◽  
Complete System ◽  
Suspension System ◽  
System Operation ◽  
Non Linear ◽  
Position Control System ◽  
Transient And Steady State ◽  
Steady State Performance

The new electrostatic suspension system (ESS) presented here is applicable to electrostatically suspended gyroscopes (ESG). The electrical disturbing torque (EDT) acting on the gyro rotor is reduced to much lower levels than possible with the conventional methods, thereby increasing the attainable accuracy of the instrument. This is achieved by eliminating the conventional pre-load voltage and instead applying only control voltages via an analogue non-linear pre-compensator to achieve linear position control system operation despite the square law relating the suspension force to the applied voltage. The transient and steady state performance of the complete system, with changes in position reference and external disturbing forces, are examined with the aid of computer simulations.

A non-linear model of a rotary pneumatic servo system

1997 ◽  
Vol 211 (2) ◽  
pp. 123-133
Author(s):  
N D Tillett ◽  
N D Vaughan ◽  
A Bowyer
Keyword(s):  
Coulomb Friction ◽  
Position Control ◽  
Servo System ◽  
Experimental System ◽  
Simulation Performance ◽  
Novel Device ◽  
Non Linear ◽  
Pneumatic Servo System ◽  
Linear Elements ◽  
Low Levels

A simulation model of a rotary pneumatic servo system has been developed and verified against an experimental system. The double-acting rotary actuator is a novel device utilizing flexible inflatable bladders. The device differs from conventional pneumatic cylinders in that it exhibits low levels of friction, as it has no sliding seals, but it does suffer from hysteresis caused by bladder distortion. The objective of this study was to develop a tool with which to investigate the effect of various forms of hysteresis and other parameters on system performance. The dynamic model utilizes a linearized analysis of pneumatic components based on earlier studies. The principal advance described in this paper relates to the inclusion of non-linear elements. These are hysteresis caused by friction or the distortion of flexible components, and a digital controller implementation. The simulation successfully predicted all major modes of behaviour. Simplified models of rubber and coulomb friction-induced hysteresis modified simulation performance in line with experimental results. An investigation in simulation showed that coulomb friction-induced hysteresis had a greater damping effect than that caused by distorting the bladders. This result applies only to position control, as hysteresis has been shown not to provide damping in trajectory control applications.

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