An approach to the design of active window shades is developed to control the direct solar gain through a window. Using simple actuation hardware and sensors, a control strategy is presented that automatically adjusts...
详细信息
An approach to the design of active window shades is developed to control the direct solar gain through a window. Using simple actuation hardware and sensors, a control strategy is presented that automatically adjusts window shades to save HVAC energy by controlling direct solar radiation passing through a window. The control algorithm is based on a simple apl,roach that admits direct light in the winter and blocks the direct light in the summer, while providing shade adjustment that affords maximum I visibility through the window. Cloudy skies or indirect sun result in horizontal placement of the shades, and the shades close at night. The implementation uses two thin film photovoltaic cells as sensors and a control algorithm that is independent of the window orientation latitude, or solar time, so that it operates properly in any installation location. Preliminary analytic and rest results show significant energy savings when the automatic window shades are compared with a window without shades, and with a window outfitted with fixed horizontal shades.
New digital control algorithms have been developed to achieve the desired transmissibility function for a microgravity isolation system. Two approaches have been presented for the controller design in the context of a...
详细信息
New digital control algorithms have been developed to achieve the desired transmissibility function for a microgravity isolation system. Two approaches have been presented for the controller design in the context of a single degree of freedom system for which an attractive electromagnet is used as the actuator. The relative displacement and the absolute acceleration of the mass have been used as feedback signals. The results from numerical studies are presented. It has been found that the resulting transmissibility is quite close to the desired function. Also, the maximum coil currents required by new algorithms are smaller than the maximum current demanded by the previously proposed lead/lag method.
Manipulators control systems must use real time algorithms to perform the trajectory planning and position control of each manipulator’s joint. The application of advanced techniques for position control, e.g., adapt...
详细信息
Manipulators control systems must use real time algorithms to perform the trajectory planning and position control of each manipulator’s joint. The application of advanced techniques for position control, e.g., adaptive control, as well as trajectory planning in cartesian space, requires a great number of real time calculations. This paper presents a system designed to teach advanced techniques of control of manipulators for undergraduate students. A controller designed with dual microprocessors, a Digital Signal Processor (DSP) TMS320C25 and a 87C51, allow the realization of such algorithms in real time. Experiments using the DSP verified the performance with the proposed algorithms.
A fast algorithm for Linear Quadratic (LQ) control with linear equality constraints is derived and exploited for stabilizing predictive control synthesis. The algorithm requires only O ( Nn ) computations for an n th ...
详细信息
A fast algorithm for Linear Quadratic (LQ) control with linear equality constraints is derived and exploited for stabilizing predictive control synthesis. The algorithm requires only O ( Nn ) computations for an n th order plant and N -steps prediction horizon, and possesses a remarkable numerical accuracy.
The computer industry has been revolutionised recently by the advent of the RISC processor, which employs a very small and simple instruction set. This paper proposes a similar approach to the algorithm set of Distrib...
详细信息
The computer industry has been revolutionised recently by the advent of the RISC processor, which employs a very small and simple instruction set. This paper proposes a similar approach to the algorithm set of Distributed control Systems, (DCSs), called ‘Reduced Algorithm Set control’ or RASC. Recent DCSs have been provided with algorithm sets of increasing complexity. Rather than simplifying the life of the control Engineer this has tended to increase the problems of implementing control strategies. Moreover, this greater complexity has been accompanied by an increase in the number of software bugs. The result is a system that is complex to understand, difficult to develop and maintain, slow in performance and full of hidden problems. RASC is a very simple but robust standard algorithm set. This can provide all the facilities the control Engineer requires to configure even the most complex of control schemes with the advantage of simplicity, ease, robustness and speed of execution. The paper defines the proposed RASC algorithm set and describes some examples of how it could be used to implement some complex control schemes.
Predictive control algorithms determine a series of the control signal minimizing the deviation between the reference and the output signal in a given future horizon. The output of the plant to be controlled is predic...
详细信息
Predictive control algorithms determine a series of the control signal minimizing the deviation between the reference and the output signal in a given future horizon. The output of the plant to be controlled is predicted on the basis of a model, which can be linear or nonlinear, parametric or nonparametric. In adaptive control these process parameters are identified and the control signal is calculated taking the identified values into consideration. In the paper simulation results present some properties of adaptive predictive control. Robustness of the control algorithm is illustrated through control of a simple Wiener model . The relationship between the plant order and the prediction horizon is also mentioned. The promising results indicate that further systematic analysis is worthwhile.
In this paper an extension of the Newton - Euler models to the case of flexible robots is achieved. Today, such models are mainly used for rigid manipulators. In this case they give the best results to solve the simul...
详细信息
In this paper an extension of the Newton - Euler models to the case of flexible robots is achieved. Today, such models are mainly used for rigid manipulators. In this case they give the best results to solve the simulation and control problems, as far as time consumption and programming simplicity are concerned. Here, the extension proposed is based on the theoretical notion of description formalism of a motion and on the use of the D'Alembert principle.
This paper is concerned with the design and implementation of user interfaces associated with construction plant and equipment and proposes some future developments that the technology under investigation offers to th...
详细信息
This paper is concerned with the design and implementation of user interfaces associated with construction plant and equipment and proposes some future developments that the technology under investigation offers to the control engineer in developing algorithms in parallel with the machine which they are seeking to control. Research at Lancaster University has achieved significant progress in the field of advanced large mobile robots for a number of years, in particular with LUCIE (Lancaster University Computerised Intelligent Excavator). For such developments the work has often been conducted either using scale models of actual plant, or computer simulations that produce predictions, generally as graphs, of the performance of the new techniques. The output of this offers an understanding of the control requirements of large complex machines operating in unstructured environments.
Model predictive control was emerging into the process industries during the 1980's. Today it is commonplace and, in some sense, mature. Commercial packages are available on a variety of platforms and ''do...
详细信息
Model predictive control was emerging into the process industries during the 1980's. Today it is commonplace and, in some sense, mature. Commercial packages are available on a variety of platforms and ''do it yourself'' implementations are also readily found. This paper takes a look at where this technology has been and where it is, and tries to predict important future developments. Some trends are clear but the range of possibilities is wide. There are many buzzwords that could describe aspects of future model predictive controllers: adaptive, non-linear, embedded, object oriented, open systems and many more. How these might fit into future model predictive controllers is explored in this paper.
Analytical formulae for designing PID controllers to give specified gain and phase margins have been proposed recently in the literature. This approach is attractive as the gain margin and phase margin serve as import...
详细信息
Analytical formulae for designing PID controllers to give specified gain and phase margins have been proposed recently in the literature. This approach is attractive as the gain margin and phase margin serve as important measures of not only performance but also robustness. Another popular approach with similar emphasis is the internal model control method. In this paper, a comparison study of these two approaches for designing a PI and a PID controller is made. The comparison shows the differences and the similarities of the two approaches. Recommendations on when and which method to apply are also given.
暂无评论