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This paper describes tuning procedures for dead-time compensating controllers (DTC). Both stable and integrating processes are considered. Simple experiments are performed to obtain process models as well as bounds on the allowable bandwidth for stability. The DTC's used have few parameters with clear physical interpretation so that manual tuning is possible. Furthermore, it is shown how the DTC's
This paper treats the problem of control signal saturation caused by feedforward control from measurable load disturbances. An efficient feedforward compensator will often give significant peaks in the control signal at fast changes in the load disturbance. These peaks may cause the control signal to reach a saturation limit. In the paper, it is shown that the anti-windup function may cause unnece
Popular Abstract in Swedish Denna avhandling presenterar några reglertekniska tillämpningar i elkraftsystem. Tillämpningarna är: hur likströmskablar påverkar båtrafik som använder magnetkompasser; frekvensmätning i elkraftsystem; algorithmer för datorbaserade reläskydd; koppling av aktiv last för att dämpa effektpendlingar.
This paper presents an analysis of the Ziegler-Nichols frequency response method for tuning PI controllers, showing that this method has severe limitations. The limitations can be overcome by a simple modification for processes where the time delay is not too short. By a major modification it is possible to obtain new tuning rules that also cover processes that are lag dominated.
Despite academic advances in PID controller design and development of automatic tuning procedures, there are still many PID controllers that are badly tuned, or not even tuned at all, in process industry. There are several reasons for this, but one major reason is that it is considered too time consuming to use current PID controller tuning methods. This paper presents a new tuning method that is
A recently published paper addressed the so called "PI+p" controller (i.e., a PI augmented with an additional, stable pole) and demonstrated that said controller yields interesting results particularly if tuned with the "contextual" approach, where model-based rules are used in conjunction with a relay experiment so as to provide at the same time the tuned regulator, and the tuning model. In this
Grain-128AEAD is a stream cipher supporting authenticated encryptionwith associated data, and it is currently in round 2 of the NIST lightweight cryptostandardization process. In this paper we present and benchmark software implementations of the cipher, targeting constrained processors. The processors chosen arethe 8-bit (AVR) and 16-bit (MSP) processors used in the FELICS-AEAD framework.Both hig
Convolutional neural networks (CNNs) have made rapid progress in the last years and in fields, such as computer vision, they are considered state-of-the-art. However, CNNs are very computationally intensive. This makes them challenging to use in embedded devices such as smartphones, security cameras and cars. This thesis investigates different neural network compression techniques to see which wi
This paper treats controller design and tuning for systems with two input signals and two output signals in the process industry. Two design methods that can be combined to form a core in an algorithm for automatic design and tuning for the considered systems are presented. The proposed controller consists of a decoupler and a diagonal PID controller. The decoupler has the property that as little
In this article it is shown how the tuning of a loop is used to commission a closed-loop performance monitoring method. The extended prediction horizon index is used to monitor disturbance rejection properties expressed with the impulse response. The impulse response is obtained from the tuning of the loop. All parameters of the monitoring method are set by using the impulse response. The presente
Mounting cameras on motorized objects has become possible in greater extent due to the emerging camera technology during the past few decades. This application could prove useful in several areas such as search and rescue operations, surveillance or even news monitoring. One hardship that this brings is the difficulty of keeping the camera unit stable while its setting is not. In the situations me
The need to preserve ecosystems to enable the reproduction of a global market-based economy has led conservationist measures that are in contradiction with a model of Development heavily based on the connectivity to broader markets. The case of protected Colombian Paramo in Sumapaz explores trails’ as a conduit to understand social mechanisms for space-time appropriations and how are they conteste
This thesis investigates what mechanisms that contribute to the interaction between lateral and vertical dynamics in a fourwheeled vehicle. For this a vehicle model was derived. To capture all the essential dynamics of the vehicle, both a horizontal model and a vertical model was used. The interaction between the models turned out to be quite evident, making it possible to use the active suspensio
