Feedback Systems ELEX 4336

• Identify the parts of a feedback system.
• Identify the forward path.
• Identify the feedback path.
• Identify the comparator.
• Make a block diagram of a feedback system.
• Given a physical description, identify the blocks.
• Construct a block diagram of the system.
• Reduce the block diagram to a simpler form.
• Use reduction rules so that the standard feedback equation can be applied.
• Reduce the block diagram to a unity feedback system.
• Derive the transfer function for each system block.
• Under the significance of mathematical modeling of system components.
• Understand and use current driven permanent magnet DC motor transfer functions.
• Understand and use voltage driven permanent magnet DC motor transfer functions.
• Derive and apply gearbox transfer functions.
• Derive and apply electrical network transfer functions.
• Derive and apply the transfer function of a given simple mechanical system.
• Derive the transfer function of the entire feedback system.
• Derive the transfer function of the entire system.
• Set up the system transfer function in standard form.
• Recognize the basic stability problem and its cause.
• Recognize there is always time delay in a feedback loop.
• Recognize the consequences of this for system stability.
• Compute the step response and frequency response for a second order system.
• Use the concepts of over, under and critical damping.
• Use the concepts of natural frequency, damped frequency, damping ratio.
• Recognize the consequences of changing the loop gain.
• Predict the type number of a system.
• Estimate the steady state error for a stable closed-loop system as a result of standard inputs step, ramp or parabolic form.
• Use control system design software to evaluate the step response of second and higher order systems.
• Become familiar with the function and use of system modeling software such as Maple or MATLAB.
• Recognize the significance of pole placement.
• Recognize the significance of the location of the poles on system stability.
• Change the position of the poles to change the system response as required.
• Use the root-locus technique as an aid in predicting system stability.
• Explain the principle of root locus plotting.
• Plot first and second order root loci by hand.
• Generate root locus plots using the software design package.
• Use root locus plots to determine system response.
• Construct frequency response plots.
• Make Bode plots for first and second order transfer functions by hand given the transfer function.
• Make use of straight line approximation techniques.
• Use the design software to make Bode plots of second and higher order systems.
• Recognize the implications to system stability of various Bode plot types.
• Design analog compensators.
• From pole placement considerations, design a simple analog compensator to achieve the required stability using frequency response methods.
• Understand the applications and limitations of PID controllers.
• Draw a block diagram of a PID controller.
• Draw circuitry to implement the controller.
• Appreciate the significance of each part of the controller.
• Understand and apply the Ziegler Nichols tuning method.
• Recognize practical limitations of modeling in feedback systems.
• Appreciate the problems due to non-linear mechanical friction.
• Appreciate the problems due to overloading of amplifiers.
• Appreciate the significance of integrator wind-up and the use of anti-windup schemes.
• Design and test various continuous time feedback control systems.
• Design and test Lead-lag, Notch filter and various PID controllers.
• Analyze and design Phase Locked motor speed controllers.
• Recognize the phase locked loop as a feedback system.
• Make a block diagram and derive the transfer function for phase locked speed controllers.
• Design and test a phase locked speed controller.
• Draw a block diagram of a basic digital control system and recognize the significance of each part.
• Describe the action of the shaft encoder, pulse counter, system clock, digital compensator, and ADC and DAC.
• Explain the advantages of a digital control system.
• Recognize that compensator transfer functions can be realized in software.
• Recognize that the parameters of a digital system are readily changed via software changes.
• Understand the sampling process and the significance of the Nyquist limit.
• Analyze and design systems consisting of a mixture of analog and digital components.
• Appreciate the dilemma in analyzing systems consisting of both discrete and continuous time components and the need to perform either s-plane or z-plane analysis.
• Design compensators using the equivalent continuous method.
• Transform s-plane transfer functions to the z-plane using various mapping techniques.
• Code and test digital controller for a servo system.
• Generate a suitable s-plane controller to stabilize a motor control system.
• Map this into the z-plane.
• Generate DSP code to implement the controller.
• Implement the controller using a small microcontroller chip.
• Set up and test the entire digital control system.

Effective as of Fall 2003