ECE Feedback Control Laboratory
ECE Feedback Control Laboratory
The ECE Feedback Control Laboratory was established in 1996 by Prof. Dan Cobb for the purposes of research and instruction in the subject of feedback control within the ECE Department at UW. This state-of-the-art laboratory accomodates faculty and student activity at all levels of study in both analog and digital control system theory, design, simulation, and testing. Among other things, the facility is intended to encourage real-world verification of innovative theoretical ideas emanating from the ECE feedback control program. It is hoped that the lab will stimulate interaction among various researchers in the ECE Department by providing an interactive environment for theory and practice.
All aboard for a Video Tour of the lab!
At present, the ECE faculty specializing in feedback control offer a single course, ECE 409: Introductory Feedback Control Laboratory, which utilizes the lab. ECE 409 is part of both the ECE Graduate Curriculum in Automatic Control and the ECE Undergraduate Curriculum in Automatic Control. The course gives students hands-on experience in applying the fundamental analog and digital control concepts covered in ECE 332, ECE 334, ECE 417, ME 446, and ME 447. It is strongly recommended that students complete two of these courses prior to taking ECE 409.
The lab contains 7 copies of most pieces of equipment. The various pieces of hardware and software can be classified as follows:
- True analog control designs can be implemented through the use of the Comdyna GP-6 analog computer. The front panel of this system allows the user to patch together linear op-amp circuits up to 4th order with banana-plug cables. +/-10V supplies are provided as well as 8 potentiometers with digital readout.
- Current gain is supplied by the Quanser Consulting Model PA0103 Power Operational Amplifier. This device is capable of driving control actuators with up to 3A of current and voltages between +/-12V.
- Reference signals are generated by the Wavetek Model 19 Function Generator. The system produces square, triangular, and sinusoidal waves at frequencies ranging from .001 Hz to 2 MHz and amplitudes from 0 to 20V p-p. Both frequency and amplitude are displayed digitally.
- The lab is equipped with Dell Optiplex 2.2 GHz Pentium 4 desktop PC's.
- Each PC contains a Data Translation DT2811 Data Acquisition board, enabling real-time processing and storage of multi-channel analog input and output data.
- Real-time data can be displayed using the Hewlett-Packard Model 54645A Digital Storage Oscilloscope. This device is capable of automatic triggering and storing analog waveforms in a digital format, facilitating transient performance analysis.
- WINDOWS 2000
- MATLAB (Version 6.5) is a high-perfomance environment for linear algebraic computation, marketed by The MathWorks. MATLAB is currently the program of choice for control system analysis and design.
- The Control Systems Toolbox (Version 5.2), an extension of MATLAB, contains routines for most control-oriented computations.
- Another extension of MATLAB, SIMULINK (Version 5.0) is a numerical simulation package for differential equations with a convenient graphical interface. SIMULINK is indispensable for simulation of a feedback system prior to testing.
- The Real-Time Workshop (Version 5.0) applies the capabilities of SIMULINK to real-time operation of the closed-loop system. Using this program, a compenstor design is reduced to executable computer code, ready to drive data-acquisition hardware.
- The Real-Time Windows Target (Version 2.2) forms the final step in compensator implementation. Executable code is loaded to data-acquisition hardware and executed. One advantage of this program is that compensator parameters can be modified and an updated executable can be loaded while the system is running.
- Microsoft Visual Studio (Version 6.0) is used by the Real-Time Workshop to compile SIMULINK files into C code for downloading to the data acquisition board.
The following electromechanical devices form the basis for control experiments in the lab. The hardware is largely modular, allowing students and researchers to piece together control problems with a wide variety of plant dynamics.
- Model SRV-02 Servo Plant: A DC servomotor with position potentiometer and an anti-backlash gear.
- Model IP-01 Inverted Pendulum: The classical 1-dimensional inverted pendulum problem on a track; potenmtiometers sense the position of both the rod and cart; the cart is driven by a DC servomotor.
- Model LFJC-01 Linear Flexible Joint: Two carts on a track connected by a spring; each cart has a position sensor; one cart is motorized.
- Model SM-01 Seesaw Apparatus: A seesaw with angular position sensor supporting one track; the track supports either an inverted pendulum or a flexible joint.