The control problem posed by tethered satellite deployment and retrieval is presently treated by means of the mission function control. Numerical simulation results indicate that mission function controllability is ef...
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The control problem posed by tethered satellite deployment and retrieval is presently treated by means of the mission function control. Numerical simulation results indicate that mission function controllability is effective in the case of a subsatellite that is connected to a main body via a tether which swings with both in-plane and out-of-plane motions. The algorithm's performance is demonstrably adequate when the three-dimensional motion of the tethered subsatellite is analytically taken into account. (O.C.)
It has been experimentally verified that the jerk of the desired trajectory adversely affects the performance of the tracking control algorithms for robotic manipulators. In this paper, we investigate the reasons behi...
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It has been experimentally verified that the jerk of the desired trajectory adversely affects the performance of the tracking control algorithms for robotic manipulators. In this paper, we investigate the reasons behind this effect, and state the trajectory planning problem as an optimization problem that minimizes a norm of joint jerk over a prespecified Cartesian space trajectory. The necessary conditions are derived and a numerical algorithm is presented.
Spark timing is one of the major parameters influencing engine performance and emissions. In most of today's automotive spark ignition (SI) engines an electronic control unit controls spark timing based on preset ...
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Spark timing is one of the major parameters influencing engine performance and emissions. In most of today's automotive spark ignition (SI) engines an electronic control unit controls spark timing based on preset values that are functions of load and speed. In this system, the preset spark timing can be different from the optimum value owing to deviations from mass production, ageing effects and a number of other factors. In the present study, a control logic is investigated for the real-time adaptation of spark timing to the optimal value. The simulation program, including an engineering model for cycle-by-cycle combustion variation, is developed for investigating the spark timing control logic. It has been found that the location of the peak pressure in the cylinder is one of the appropriate parameters used to estimate the optimum spark timing. It is also shown that experimental results reflect the simulation outputs and reasonableness of the spark timing control logic for location of the peak pressure.
The development of lightweight flexible structures that include both advanced control and active material will impact several space application areas. One way to reduce vibration is the combination of advanced control...
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The development of lightweight flexible structures that include both advanced control and active material will impact several space application areas. One way to reduce vibration is the combination of advanced control methods such as nonlinear adaptive control plus active structure technology. Active structures with both sensors and actuators, strategically placed along the structure, can suppress vibrations and enhance slewing performance. Active vibration suppression is accomplished with a graphite/epoxy composite structure that includes embedded strain sensors and actuators.
With all control schedules, the management of diabetes is possible using Skyler's algorithm. In general, those control algorithms which do not allow the individual adaptation to changing conditions lead to overins...
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With all control schedules, the management of diabetes is possible using Skyler's algorithm. In general, those control algorithms which do not allow the individual adaptation to changing conditions lead to overinsulinisation. So-called meal-related algorithms do usually minimise the fluctuations in blood sugar. The introduction of self-adapting algorithms, detecting peripheral insulin resistance, may further improve metabolic diabetes control.
A system for automatic control of a three-step process of water purification is developed. The system includes the online monitoring of the concentrations of pollutants in water at points of the flow diagram correspon...
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A system for automatic control of a three-step process of water purification is developed. The system includes the online monitoring of the concentrations of pollutants in water at points of the flow diagram corresponding to the primary, fine, and final treatment steps, and consists of a UV-fluorimeter for determining the concentrations of pollutants, solenoid valves for controlling the flow of water in the treatment installation and a computerized central control unit operating according to a preset algorithm of water treatment control.
control algorithms are proposed for on-line computer control of the repetitive-accelerator fast-pulsed reactor. Firstly, simplification of the reactor core dynamics is obtained by regression analysis technique in orde...
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control algorithms are proposed for on-line computer control of the repetitive-accelerator fast-pulsed reactor. Firstly, simplification of the reactor core dynamics is obtained by regression analysis technique in order to obtain a compact model of the pulsed reactor. Secondly, a start-up control algorithm to avoid severe thermal shock in the fuel rod is proposed. This is essentially a programmed control, whereby the external neutron source from the accelerator and the external reactivity are controlled in such manner that the fuel temperature would follow a predetermined time trajectory. Applicability of the method to the reactor start-up is proved by a computer simulation experiment. Thirdly, a control concept for constant power operation is proposed. This is composed of two control loops: (1) a fine control loop, which responds quickly to small variations of reactor power, and (2) a diagnosis and adaptation loop, which judges whether a large deviation from set-up value observed on the reactor power output is due to an abnormality in the external neutron source, or to a change of the set-up value itself, and then adaptively returns the reactor power to the set-up value. A computer simulation experiment demonstrated the validity of the control system characteristics. A discussion is also presented on the problems foreseen in applying the proposed methods to the actual design of a digital computer control system.
To solve the problem of compensating the influence of a disturbance on the angular position of a spacecraft, we propose an engineering technique for developing an algorithm for controlling a flywheel attitude control ...
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To solve the problem of compensating the influence of a disturbance on the angular position of a spacecraft, we propose an engineering technique for developing an algorithm for controlling a flywheel attitude control and stabilization system, based on selective invariance of the control system and the signal counter-accumulation circuit. This method is confirmed to be effective by numerical simulation.
Sensor management schemes have recently been proposed to reduce the tracking demands on multisensor systems while minimizing the loss of tracking performance by selecting only enough sensing resources to maintain a de...
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Sensor management schemes have recently been proposed to reduce the tracking demands on multisensor systems while minimizing the loss of tracking performance by selecting only enough sensing resources to maintain a desired covariance level for each target. However, covariance control algorithms to date have not addressed the presence of clutter measurements and the need for data association in those cases. This note presents a method of reducing the effects of probabilistic data association on covariance control algorithms through the addition of a scalar loss of information parameter. Whereas single-sensor management systems have been designed for the probabilistic data association filter (PDAF), including one that uses the loss of information parameter to approximate the covariance calculation, no sensor managers to date haw been designed around the multisensor extension of the PDAF. Monte Carlo simulations show that, without this parameter, the co variance control system is unable to maintain the desired covariance resulting in a much larger actual covariance level. Use of the loss of information parameter generally restores system performance.
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