Laboratory Processes

The tanks (Fig 1) are the workhorses for the introductory courses in control for E, FD, and K. They are used to illustrate PI and PID control, process modeling, state feedback and observers. The systems are highly intuitive. Disturbances can be introduced manually by pouring water into the tanks, measurement noise can be introduced by blowing air into the tanks. The tanks are connected to PCs via the panel (Fig 2) The PCs have a nice intuitive man-machine interface (Fig 3).

There is also a time-delay unit (Fig 4) for the tanks which makes it possible to introduce a considerable time delay in the system.

The Quadruple Tank (Fig 5). This is a modification of the basic tanks made by Karl Henrik Johansson. The system has four tanks and two pumps. It is a multivariable system with a transmission zero that can be moved from the LHP to the RHP by changing the flows. The panel for the system is shown in Figure 6.

The DC Servo (Fig 7) is the work horse for the introductory course for M. The system has a DC motor with a gear box, a heavy inertia load, and an extra DC motor which can be used either as a tachometer or as a torque generator. It is used to illustrate dynamics, simple feedback, PI, PID, velocity feedback, tachometer feedback, observers, and state feedback. It is easy to do simple feedback directly from the panel by cables. Gains can be changed using potentiometers. In this way we can give simple demonstrations of compliance control.

The Ball and Beam (Fig 8) has a strong DC torque generator and a tachometer. The beam has full rotational freedom. The available torque makes it easy to throw the ball long distances. There is also a device for feeding balls onto the beam. Another version (Fig 9) of the ball and beam has a motor with a harmonic drive.

The TIT pendulum (Fig 10). This is a version of the Tokyo Institute of Technology rotational pendulum developed by Professor Furuta. The pendulum has slip rings and a strong DC motor. It is used for experiments with stabilization, swing-up, and hybrid control. The system is mostly used in advanced courses and projects.

The fan and plate system (Fig 11) is a typical example of a system with oscillatory modes. The purpose is to position the plate by blowing with the fan. The dynamics can easily be changed by moving the fan.

The teapot(Fig 12) is a simple system used to demonstrate sequential control. It is used in courses for chemical engineers. The system is normally run together with a soft PLC from ABB Automation.

The Lego factory (Fig 13) is another plant that is used to illustrate discrete control. The system is a factory made out of Lego bricks to produce Lego cars. The system is used in the course Real-Time Systems and in projects.

The bead sorter (Fig 14) is a commercial system that is used to illustrate discrete control. Black and yellow beads can be sorted and organized in different patterns. The system is used in the course in Real-Time Systems and in projects.

The motion control system (Fig 15) is a commercial product form ECP that is used in the courses in Computer Controlled Systems. It is a typical example of a system where more complicated control strategies can outperform PID control. Many different ideas can be illustrated using the system.

The air throttle (Fig 16) is a good example of a nonlinear system taken from industry. This type of throttle unit is mounted in most new Volvo cars since 1999 to control the airflow to the engine. The process is used in the course in Nonlinear Control and Servo Systems to illustrate dead-zone compensation. It has also been used in projects in System Identification.