"Control - The Hidden Technology"
By Doug Peterson
It was one of the most important inventions in the history of mass communications. But for reasons unknown, this groundbreaking invention languished in a patent office for about 11 years before it finally saw the light of day, said Karl Astrom in a special presentation as part of CSL's Golden Anniversary lecture series.
The invention was the negative feedback amplifier, a control system that made it possible to overcome one of the major hurdles of long-distance communication - how to amplify a person's voice without amplifying the noise and distortion that came with the signal.
Without it, there would have been no long-distance telephone and television networks.
Astrom, professor of automatic control at the Lund Institute of Technology in Sweden, cited the negative feedback amplifier as one of the landmarks in control system history. It is also a prime example of what he calls "the hidden technology."
Control systems are all around us - in our cars, airplanes, power generators, even our CD players. They are widely used and hugely successful, he said. But control systems seldom get public attention, except when one of them fails and disaster strikes. They typically remain hidden, tucked deep inside the hardware.
In his CSL Golden Anniversary talk, Astrom traced the history of automatic control systems in three primary areas - industrial process control, vehicle control and communication.
In vehicle control, for instance, Astrom zeroed in on flight control, beginning with the Wright Brothers' landmark flight at Kitty Hawk, North Carolina, in 1903. Quoting Wilbur Wright, Astrom said aviation pioneers knew how to construct airplanes before 1903. But there were serious problems. Pre-Kitty Hawk planes were stable, but their inherent stability also made them difficult to maneuver.
In other words, the obstacle was one of control.
"When this one feature has been worked out," Wright said in 1901, "the age of flying will have arrived."
The Wright Brothers went on to reject the dogma that aircraft should be inherently stable. And the result was an airplane that could be balanced and steered. From that point, planes rapidly advanced to where automatic control systems could eventually steer an airplane across the Atlantic Ocean with no human hands on the controls. This milestone was reached in 1947, Astrom noted, much earlier than most people suppose.
As he put it, automatic control is the soul of technology today. By this, Astrom means that automatic control is a collection of ideas, concepts and theories that can be implanted into many different areas. Control theories can be applied to transportation, communication, mechatronics, physics, biology, manufacturing and energy generation, to name just a few.
But because control applies to so many fields, historically it has been difficult to know where to place it within the university structure.
That's the beauty of CSL, Astrom said. As an interdisciplinary laboratory, CSL found a home for automatic control in the University of Illinois academic environment.
"CSL is a unique creation," he said. "You created a platform for people coming from all possible directions to work together. And it certainly has proven extremely successful."
By Doug Peterson
It was one of the most important inventions in the history of mass communications. But for reasons unknown, this groundbreaking invention languished in a patent office for about 11 years before it finally saw the light of day, said Karl Astrom in a special presentation as part of CSL's Golden Anniversary lecture series.
The invention was the negative feedback amplifier, a control system that made it possible to overcome one of the major hurdles of long-distance communication - how to amplify a person's voice without amplifying the noise and distortion that came with the signal.
Without it, there would have been no long-distance telephone and television networks.
Astrom, professor of automatic control at the Lund Institute of Technology in Sweden, cited the negative feedback amplifier as one of the landmarks in control system history. It is also a prime example of what he calls "the hidden technology."
Control systems are all around us - in our cars, airplanes, power generators, even our CD players. They are widely used and hugely successful, he said. But control systems seldom get public attention, except when one of them fails and disaster strikes. They typically remain hidden, tucked deep inside the hardware.
In his CSL Golden Anniversary talk, Astrom traced the history of automatic control systems in three primary areas - industrial process control, vehicle control and communication.
In vehicle control, for instance, Astrom zeroed in on flight control, beginning with the Wright Brothers' landmark flight at Kitty Hawk, North Carolina, in 1903. Quoting Wilbur Wright, Astrom said aviation pioneers knew how to construct airplanes before 1903. But there were serious problems. Pre-Kitty Hawk planes were stable, but their inherent stability also made them difficult to maneuver.
In other words, the obstacle was one of control.
"When this one feature has been worked out," Wright said in 1901, "the age of flying will have arrived."
The Wright Brothers went on to reject the dogma that aircraft should be inherently stable. And the result was an airplane that could be balanced and steered. From that point, planes rapidly advanced to where automatic control systems could eventually steer an airplane across the Atlantic Ocean with no human hands on the controls. This milestone was reached in 1947, Astrom noted, much earlier than most people suppose.
As he put it, automatic control is the soul of technology today. By this, Astrom means that automatic control is a collection of ideas, concepts and theories that can be implanted into many different areas. Control theories can be applied to transportation, communication, mechatronics, physics, biology, manufacturing and energy generation, to name just a few.
But because control applies to so many fields, historically it has been difficult to know where to place it within the university structure.
That's the beauty of CSL, Astrom said. As an interdisciplinary laboratory, CSL found a home for automatic control in the University of Illinois academic environment.
"CSL is a unique creation," he said. "You created a platform for people coming from all possible directions to work together. And it certainly has proven extremely successful."
Karl Astrom
Professor of Automatic Control
Lund Institute of Technology, Sweden
Presentation Title: "ControlThe Hidden Technology"
Delivered: February 20, 2001
Professor of Automatic Control
Lund Institute of Technology, Sweden
Presentation Title: "ControlThe Hidden Technology"
Delivered: February 20, 2001
