Rudolf Emil Kálmán (May 19, 1930 – July 2, 2016) was a

Hungarian-American Hungarian Americans ( Hungarian: ''amerikai magyarok'') are Americans of Hungarian descent. The U.S. Census Bureau has estimated that there are approximately 1.396 million Americans of Hungarian descent as of 2018. The total number of people wit ...

electrical engineer Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

, mathematician, and inventor. He is most noted for his co-invention and development of the Kalman filter, a mathematical algorithm that is widely used in signal processing,

control system A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial c ...

s, and guidance, navigation and control. For this work, U.S. President Barack Obama awarded Kálmán the National Medal of Science on October 7, 2009.

Life and career

Rudolf Kálmán was born in Budapest, Hungary, in 1930 to Otto and Ursula Kálmán (née Grundmann). After emigrating to the United States in 1943, he earned his bachelor's degree in 1953 and his master's degree in 1954, both from the Massachusetts Institute of Technology, in

electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

. Kálmán completed his doctorate in 1957 at Columbia University in New York City. Kálmán worked as a Research Mathematician at the

Research Institute for Advanced Studies The Baltimore-based Research Institute for Advanced Studies (RIAS), not to be confused with the better-known Institute for Advanced Study in Princeton, New Jersey, was among the several centers for research in the mathematical and physical science ...

Baltimore, Maryland Baltimore ( , locally: or ) is the most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic, and the 30th most populous city in the United States with a population of 585,708 in 2020. Baltimore was ...

, from 1958 until 1964. He was a professor at

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...

from 1964 until 1971, and then a Graduate Research Professor and the Director of the Center for Mathematical System Theory, at the University of Florida from 1971 until 1992. He periodically returned to

Fontainebleau Fontainebleau (; ) is a commune in the metropolitan area of Paris, France. It is located south-southeast of the centre of Paris. Fontainebleau is a sub-prefecture of the Seine-et-Marne department, and it is the seat of the ''arrondissement ...

from 1969 to 1972 at MINES ParisTech where he served as scientific advisor for Centre de recherches en automatique. Starting in 1973, he also held the chair of Mathematical System Theory at the

Swiss Federal Institute of Technology The Swiss Federal Institutes of Technology are two institutes of higher education in Switzerland (part of the ETH Domain): * Swiss Federal Institute of Technology in Lausanne Swiss may refer to: * the adjectival form of Switzerland *Swiss people ...

in Zürich, Switzerland. Kálmán died on the morning of July 2, 2016, at his home in

Gainesville, Florida Gainesville is the county seat of Alachua County, Florida, Alachua County, Florida, and the largest city in North Central Florida, with a population of 141,085 in 2020. It is the principal city of the Gainesville metropolitan area, Florida, Gaine ...

Work

Kálmán was an

by his undergraduate and graduate education at

M.I.T The Massachusetts Institute of Technology (MIT) is a Private university, private Land-grant university, land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern t ...

. and Columbia University, and he was noted for his co-invention of the Kalman filter (or Kalman-Bucy Filter), which is a mathematical technique widely used in the digital computers of

s, navigation systems, avionics, and outer-space vehicles to extract a signal from a long sequence of noisy or incomplete measurements, usually those done by electronic and gyroscopic systems. Kálmán's ideas on filtering were initially met with vast skepticism, so much so that he was forced to do the first publication of his results in mechanical engineering, rather than in electrical engineering or systems engineering. Kálmán had more success in presenting his ideas, however, while visiting

Stanley F. Schmidt Stanley F. Schmidt (January 21, 1926 – August 13, 2015) was an American aerospace engineer who pioneered the Schmidt-Kalman filter used in air and space navigation, most notably in Apollo spacecraft. Early life and education Schmidt was born ...

at the NASA Ames Research Center in 1960. This led to the use of Kálmán filters during the Apollo program, and furthermore, in the NASA Space Shuttle, in Navy

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

s, and in unmanned aerospace vehicles and weapons, such as

cruise missile A cruise missile is a guided missile used against terrestrial or naval targets that remains in the atmosphere and flies the major portion of its flight path at approximately constant speed. Cruise missiles are designed to deliver a large warhe ...

s. Kálmán published several seminal papers during the sixties, which rigorously established what is now known as the

state-space representation In control engineering, a state-space representation is a mathematical model of a physical system as a set of input, output and state variables related by first-order differential equations or difference equations. State variables are variables wh ...

of dynamical systems. He introduced the formal definition of a system, the notions of controllability and observability, eventually leading to the

Kalman decomposition In control theory, a Kalman decomposition provides a mathematical means to convert a representation of any linear time-invariant (LTI) control system to a form in which the system can be decomposed into a standard form which makes clear the observa ...

. Kálmán also gave groundbreaking contributions to the theory of

optimal control Optimal control theory is a branch of mathematical optimization that deals with finding a control for a dynamical system over a period of time such that an objective function is optimized. It has numerous applications in science, engineering and ...

and provided, in his joint work with J. E. Bertram, a comprehensive and insightful exposure of

stability theory In mathematics, stability theory addresses the stability of solutions of differential equations and of trajectories of dynamical systems under small perturbations of initial conditions. The heat equation, for example, is a stable partial diffe ...

for dynamical systems. He also worked with B. L. Ho on the

minimal realization In control theory, given any transfer function, any state-space model that is both controllable Controllability is an important property of a control system, and the controllability property plays a crucial role in many control problems, such as ...

problem, providing the well known Ho-Kalman algorithm.

Awards and honors

Kálmán was a foreign member of the

French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...

, Hungarian and Russian Academies of Sciences, as well as a member of the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...

, the National Academy of Engineering, and the American Academy of Arts and Sciences. He has been awarded many honorary doctorates from other universities. In 2012 he became a fellow of the American Mathematical Society. Kálmán received the

IEEE Medal of Honor The IEEE Medal of Honor is the highest recognition of the Institute of Electrical and Electronics Engineers (IEEE). It has been awarded since 1917, when its first recipient was Major Edwin H. Armstrong. It is given for an exceptional contribution ...

in 1974, the

IEEE Centennial Medal The IEEE Centennial Medal was a medal minted and awarded in 1984 ''to persons deserving of special recognition for extraordinary achievement'' to celebrate the Centennial of the founding of the Institute of Electrical and Electronics Engineers (I ...

in 1984, the Inamori foundation's Kyoto Prize in Advanced Technology in 1985, the

Steele Prize The Leroy P. Steele Prizes are awarded every year by the American Mathematical Society, for distinguished research work and writing in the field of mathematics. Since 1993, there has been a formal division into three categories. The prizes have ...

of the American Mathematical Society in 1987, the Richard E. Bellman Control Heritage Award in 1997, and the National Academy of Engineering's Charles Stark Draper Prize in 2008. Kálmán also received an Honorary Doctorate from

Heriot-Watt University Heriot-Watt University ( gd, Oilthigh Heriot-Watt) is a public research university based in Edinburgh, Scotland. It was established in 1821 as the School of Arts of Edinburgh, the world's first mechanics' institute, and subsequently granted univ ...

in 1990. and an Honorary doctorate from the Politecnico di Milano in 2012. Kalman died a few weeks before the conferment of the latter doctorate, so that his wife Dina attended the ceremony on his behalf, held in the Conference room of the Departement of Electronics, Information and Bioengineering of the Politecnico di Milano on 12 September 2016.

Selected publications

* * * * * * *

References

External links

The Kalman Filter website
*For Kálmán's PhD students se
Rudolf Emil Kálmán
on th
Mathematics Genealogy Project
page. * *A biography by Kalman's Ph.D. advisor, J R Ragazzini is given in "Dynamical Systems, Measurement, and Control", June 1977 pp. 73–75. This also has a list of Kalman's major publications.
Biography of Kalman
from the IEEE {{DEFAULTSORT:Kalman, Rudolf Emil 1930 births 2016 deaths 20th-century American mathematicians 21st-century American mathematicians American electrical engineers American inventors American people of Hungarian-Jewish descent Columbia School of Engineering and Applied Science alumni Control theorists Electrical engineering academics Academic staff of ETH Zurich Fellows of the American Mathematical Society Foreign Members of the Russian Academy of Sciences Hungarian emigrants to the United States IEEE Centennial Medal laureates IEEE Medal of Honor recipients Draper Prize winners Kyoto laureates in Advanced Technology MIT School of Engineering alumni Members of the French Academy of Sciences Members of the Hungarian Academy of Sciences Members of the United States National Academy of Engineering Members of the United States National Academy of Sciences Richard E. Bellman Control Heritage Award recipients Stanford University faculty Systems engineers University of Florida faculty