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The optimal control of the heating, ventilation, and air-conditioning (HVAC) system in buildings has a significant energy saving potential and therefore is of a great practical interest. An event-based HVAC control adjusts control actions when certain events occur, which may be faster and more scalable than state-based or time-driven control methods. However, events may capture either local or global changes in the rooms. The choice of events is a tradeoff between the computational efficiency and the control performance. This challenging problem remains open. We consider this as an important problem in this paper and make three major contributions. First, we define local and global events for the HVAC control problem. The complexity of these event-based control policies is defined. Second, based on hypothesis testing, we develop a method to select events that capture a sufficient state information and with a relatively small event space. Third, we demonstrate the performance of this method on two groups of examples, including one group of small-scale problems for the proof of concept and the other group of large-scale problems in the HVAC control. It is shown that our method outperforms the Levin search, which is a traditional complexity-based search method and finds event-based HVAC control policies with a good performance. Note to Practitioners—When there are multiple rooms in a building, the HVAC control may achieve a significant energy saving and an indoor comfort satisfaction in the same time through exploring the coupling among the rooms. By appropriately defining the events, the size of the event space is usually much smaller than the state space. Therefore, an event-based control is more scalable and preferred in practice. Local events capture the state changes of rooms in a small neighborhood, which leads to a small event space but limited information. Global events capture the state changes of rooms in a large neighborhood, which leads to more information but a large event space. It remains open how to select events in large-scale HVAC control problems, especially when the computing budget is limited. In this paper, we define the complexity of an event-based control policy by the number of neighboring rooms considered. We develop a method based on hypothesis testing to select events with a proper complexity in order to achieve a good system performance. The performance of this method is demonstrated on an HVAC control problem. [ABSTRACT FROM AUTHOR]

Practical applications of controllers often impose further requirements on the implementation beyond the actual control performance, such as the ability to switch between manual and automatic control or between different control laws or controller parameter settings, known as bumpless transfer. Another common requirement is to limit the control signal in magnitude and/or rate. This paper examines and extends several discrete-time variants of active disturbance rejection control (ADRC), which is increasingly being applied especially in the field of power electronics and drives, in this regard. Detailed guidelines for practical ADRC implementations with these abilities are presented, and all features are being demonstrated with the help of simulation examples. [ABSTRACT FROM PUBLISHER]

During the first long shutdown (LS1) of the Large Hadron Collider (LHC), the protection system for the superconducting elements of the LHC will substantially be upgraded with the principal objectives to extend its diagnostic capabilities and to enhance the system immunity to ionizing radiation. All proposed measures will improve the overall system dependability as well. The supervision of the quench heater circuits of the LHC main dipoles will be enhanced by adding additional measurement channels for the discharge current and increasing the sampling frequency and resolution of the related data acquisition systems. By these measures it will be possible to identify potential fault states of the quench heater circuits, which may affect the integrity of the concerned magnets. At this occasion all main dipole protection systems will be submitted to general overhaul after four years of successful operation. Within the radiation to electronics project, the upgrade of the protection systems will be concluded by installing the latest versions of radiation tolerant quench detection electronics. In addition some equipment will be relocated to shielded areas. [ABSTRACT FROM PUBLISHER]

This paper describes a real-time transfer control method to produce a high throughput for linear tools of semiconductor manufacturing equipment. We developed a transfer control method for various process times with two steps during operation of the equipment. The first step uses a local search to find a transfer sequence producing a high throughput in advance for various process times, and the second step switches between transfer sequences during the operation of the equipment by referring to a decision tree made from the results of the first step. The method calculates the transfer sequence in a time period from recognizing the process time to the start of transferring the wafer and improves the throughput of linear tools in more than 60% of the tested process time combinations. In the most improved case, the throughput improved by 53%. [ABSTRACT FROM AUTHOR]

The payload oscillation inherent to all cranes makes it challenging for human operators to manipulate payloads quickly, accurately, and safely. Manipulation difficulty is also increased by nonintuitive crane-control interfaces. This paper describes a new interface that allows operators to drive a crane by moving a hand-held device (wand or glove) freely in space. A crane-mounted camera tracks the movement of the hand-held device, the position of which is used to drive the crane. Two control architectures were investigated. The first uses a simple feedback controller, and the second uses feedback and an input shaper. Two operator studies demonstrate that hand-motion crane control is faster and safer than using a standard push-button pendent control. [ABSTRACT FROM PUBLISHER]

In this paper, we present a novel end-effector (payload) motion-based control development approach for the regulation of underactuated overhead cranes, which is efficient even in the presence of external disturbance and system parameter variations/uncertainties. The control system is elegantly constructed so that the problem of simultaneously regulating the trolley motion and suppressing the payload swing is successfully addressed by stabilizing a newly defined payload motion signal. Specifically, we first couple the actuated trolley motion and the unactuated payload swing via the defined payload motion signal, based on which a new energy storage function is established. Consequently, a payload motion-based control law is constructed straightforwardly, and the equilibrium point of the resulting closed-loop system is proven to be asymptotically stable by Lyapunov techniques and LaSalle's invariance theorem. Unlike traditional energy-based controllers, the proposed control law takes a much simpler structure independent of the system parameters. Both simulation and experimental results are included to demonstrate the superior performance of the proposed control method over some traditional controllers and its robustness against parameter variations, which illuminates the promising practical application potentiality of the designed crane control system. [ABSTRACT FROM PUBLISHER]

In most applications where motors control several degrees of freedom of a mechanical system, there is the necessity to implement protection that is able to stop the motors when the mechanical system reaches the extreme positions of its workspace. When the mechanical system is located in a hostile environment and/or when the limit positions define a complex surface, the protection strategy cannot be always implemented by simply placing sensors and limit switches in the proximity of the limit positions. We present in this paper a solution for the protection problem, which employs a model-based algorithm capable of estimating in real time the system state variables. The idea of the model-based protection scheme is to implement a model of the mechanical system forced by the emergency braking actions in order to predict, using the current estimated state of the system as initial condition, the trajectory of relevant system outputs, together with their uncertainties, during the braking transient. If the probability that the predicted output trajectories intercept the physical boundaries of the workspace exceeds a predefined threshold, the protection trips. With this approach, we aim to reach a greater exploitation of the system workspace than with a fixed-threshold algorithm, since in this case, the threshold is adapted to the current system state. In this paper, the aforementioned algorithm is developed for a particular application, namely, the protection of a set of steering microwave antennas placed in a hostile environment (hard vacuum condition, strong neutron and gamma radiation, and strong magnetic fields) inside a nuclear-fusion reactor. However, it is the opinion of the authors that the same procedure could also find good application in other systems that need protection with similar characteristics. Some simulations and preliminary test results will be also presented in order to better clarify how the protection works, and finally, some implementation issues will be discussed. [ABSTRACT FROM PUBLISHER]