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We consider the classical 3-state Moore-Greitzer model, which is commonly used for approximating dynamics of deviations of flow and pressure variables in an axial compressor from their nominal steady-state values. The linearization of the nonlinear system is not controllable and, therefore, even local asymptotic stability cannot be achieved using methods of linear control theory. We propose a fami
Industrial robots are important when the degree of automation in industry is increased. To enable the use of robots also when the products change rapidly, the programming must be quick and easy to perform. One way to accomplish this is to use lead-through programming, i.e., the user manually guides the robot. This paper presents a sensorless approach, and thus avoids the need for a typically expen
Abstract in UndeterminedStabilization and optimal control is studied for state space systems with nonnegative coefficients (positive systems). In particular, we show that a stabilizing distributed feedback controller, when it exists, can be computed using linear programming. The same methods are also used to minimize the closed loop input-output gain. An example devoted to distributed control of a
To the purpose of marine seismic acquisition, new acoustic sources have been developed to reduce the environmental impact. The use of marine vibrators makes it possible to define emission frequency ranges, consequently allowing limitation of the frequencies that disturb marine animal life. Constructing marine vibrators with high efficiency and linear dynamics is however difficult, and the vibrator
A particle filter based solution to the out-of-sequence measurement (OOSM) problem is proposed. The solution is storage efficient, while being computationally fast. The filter approaches the multi-OOSM problem by not only updating the estimate at the most recent time, but also for all times between the OOSM time and the most recent time. This is done by exploiting the complete in-sequence informat
The simultaneous localization and mapping problem is approached by using an ultrasound sensor and wheel encoders. To be able to account for the low precision inherent in ultrasound sensors, the occupancy grid notion is extended. The extension takes into consideration with which angle the sensor is pointing, to compensate for the issue that an object is not necessarily detectable from all position
Distributed Decision Making and Control is a mathematical treatment of relevant problems in distributed control, decision and multi-agent systems, The research reported was prompted by the recent rapid development in large-scale networked and embedded systems and communications. One of the main reasons for the growing complexity in such systems is the dynamics introduced by computation and communi
The strong process forces arising during high-speed machining operations, combined with the limited stiffness of industrial robots, have hampered the usage of industrial robots in high-end milling tasks. However, since such manipulators may offer flexible and cost-effective machining solutions, a three-dimensional piezo-actuated compensation mechanism, which aims to compensate for the positioning
A correct design of controllers must necessarily account for the schedule of the controller task over the processor. Existing design techniques are based on the assumption that there is no delay, or the delay is constant over time. However, in practice, almost all controllers have time-varying delay, hence invalidating this assumption. In this paper, we introduce a period design policy, in which t
We present a framework for the solution of control and estimation problems under a signal-to-noise (SNR) ratio constraint. The framework can be used to design optimal linear controllers, based on output feedback, with two degrees of freedom: One part of the controller is placed before the communication channel and represents sensing and encoding operations. The other part represents decoding and i
Joint wheel-slip and vehicle-motion estimation is considered, based on measurements from wheel encoders, an inertial measurement unit, and a global positioning system (GPS). The proposed strategy effectively employs the Rao-Blackwellized particle-filtering framework using a kinematic model. Key vari- ables in active safety systems, such as longitudinal velocity, roll angle, and wheel slip for all
This paper presents a scheme to construct distributed observers for a system consisting of agents interconnected in a graph structure. The scheme is an iterative procedure to improve the observers with respect to global performance. It is modular in the sense that each agent iterates using only local model information. As a consequence, the complexity of the scheme scales linearly with the size of
In production industry today a lot of engineering time is required to develop and maintain control applications. One part of the control applications are the state machines which typically are written in Grafcet/SFC. Several efforts have been made to extend Grafcet/SFC to achieve more effective and convenient development, e.g. by introducing hierarchical structuring, reusable sub-state machines, a
