Dr. Carlos L. Castillo

 

Research

My research interests are in Control Systems, Estimation theory, Fault-tolerant Systems and Robotics. I am currently working in the implementation of Real-Time Advanced Control Systems and Observers/Estimators.

Control Systems

Since their inception, control systems have been an enabling technology. Control systems were introduced during the industrial revolution with devices like the James Watt flyball governor,. Over the past 40 years, the developments in analog and digital electronics have resulted in dramatic increases in the computational power of microcomputers and microcontrollers. These developments provided for the implementation of advanced control techniques. These advanced control techniques enabled the successful development of high performance applications such as:

  • Control systems in the manufacturing industries from automotive to integrated circuits, which are associated with computer-controlled machines, provide the precise positioning and assembly required for high-quality, high-yield fabrication of components and products, [1].
  • Industrial process control systems, particularly in the hydrocarbon and chemical processing industries, maintain high product quality. Product quality is maintained by monitoring thousands of sensors signals and making corresponding adjustments to hundred of valves, heaters, pumps and other actuators, [1].
  • Control of communication systems such as the telephone system, cell phones, and the Internet are especially pervasive. These control systems regulate the signal power levels in transmitters and repeaters, manage packet buffers in network routing equipment and provide adaptive noise cancelation to respond to varying transmission line characteristic, [1].

Control systems have reached a high level of theoretical development and there exists a myriad of applications. However, the development of new sensors and actuators for old and new applications continues. Therefore, the demand for new theoretical concepts and approaches, to handle increasingly complex applications remains high.

Estimation theory

The need to extract or estimate useful information, from noisy signals or from partial information sources, is almost pervasive in most of the real-world signal processing and control systems. Estimating the values of signals or parameters is a fundamental part of many signal-processing systems. In the particular case of control systems, the requirement is pervasive to use an algorithm to obtain measured outputs and the estimated values of the state variables of the process from noise. The Kalman filters are the most commonly used algorithm for the purposes of extracting information from noise.

Fault-tolerant Systems

Stringent requirements for safety, reliability and profitability are demanded for the chemical and manufacturing industries. These requirements have generated the necessity of designing control systems with the ability of handling defects/malfunctions in process equipment, communication networks, sensors and actuators, [4]. Issues related to faults may include physical damage to the process equipment, misuse of raw material and energy resources, increase in the downtime for process operation resulting in significant production losses and jeopardizing personnel and environmental safety [2]. Management of abnormal situations is a challenge in the chemical industry since abnormal situations account annually for 10 billion in lost revenue in the U.S. alone, [3]. Aside from the economical implications, which failures in technological systems imply, the loss of life is also a fundamental reason for designing control systems capable of handling systems’ components faults or failures. Reliability and operational safety is one of the main research focus areas in the design of current and future control systems of UAVs.

Robotics

Under construction

  1. R. M. Murray, K. J. Åström, S. P. Boyd, R. W. Brockett and G. Stein, “Future Directions in Control in an Information-Rich World”, IEEE Control Systems Magazine, pp. 20-33, 2003
  2. C. W. McFall, “Integrated Fault Detection and Isolation and Fault-Tolerant Control of Nonlinear Process Systems”, Ph.D. thesis, Chemical Engineering Department, University of California Los Angeles, 2008
  3. A. Gani, “Fault-Tolerant Process Control: Handling Actuator and Sensor Malfunctions”, Ph.D. thesis, Chemical Engineering Department, University of California Los Angeles, 2007
  4. “Aerovironment, Inc.”, http://www.aerovironment.com/