From given specifications determine the damping ratio and the natural frequency. Apr 22, 2017 a lead compensator design example is worked based on improving transient time domain specifications. This is intended primarily for btech electrical and electronics students. To see which one, consider the 5thorder system from our previous lecture. Design via root locus elec304alper erdogan 1 1 lecture 1.
When the main task is increasing the phase margin to a target value, the following. A number of matlab functions are developed that automate the compensator design procedure. Design of lead compensator for process control using multisim. In order to use the root locus method to design the lead compensator the root locus of the feedforward path of the the system has to be drawn same goes if we want to use the bode plot for the design process. Lead or phase lead compensator using frequency response. May 25, 2012 the steps to design the lead compensator are with root locus are. Phase lead compensator design using bode plots, a slightly di. This has been the most difficult part for me since i started writting this series.
Evaluate the steady state performance of the lead compensated system to. You can add dynamics and modify compensator parameters using the compensator editor or using the graphical bode editor, root locus editor, or nichols editor plots compensator editor. Then design the lag compensator to meet the sse specifications. Design via root locus elec304alper erdogan 1 35 two approaches for feedback compensation 1. Laser guided missile control system can be designed to gain insight into a variety of concepts, including stabilization of unstable systems, compensation properties, nichols. The transfer fcn lead or lag block implements a discretetime lead or lag compensator of the input. Compensator design for a set of plant models matlab. Designing a lead compensator with bode plot youtube. Build the simulink model and once completed, connect to target. Lead mechanics ii adding a lead to the ltf changes both the magnitude and phase, so it is di.
Design analysis of phase lead compensation for typical laser. Lead lag compensator using either root locus or frequency response. To design a passive rc lead compensating network for the given specifications, viz. Finally, the result of phase lead and phase led compensator is presented by using matlab gui. Design example 1 design a lead compensator for the digital control system below. Analysis of phase lead compensator design for laser guided. A number of matlab function are developed for the compensator design method. To interactively shape the openloop response using control system designer, use the bode editor.
In this page, you will learn how to design digital lead and lag compensators using the rootlocus design method. I will try to be as brief as possible the underlying concepts have to be studied from standard text books. Run the command by entering it in the matlab command window. This response does not satisfy the 5% overshoot design requirement. The design process of phaselead, lag, leadlag, and cascaded lead controllers is performed by applying the principles of the root locus technique 2628, using matlab sisotool 2931. With this design tool, control engineers would be able to rapidly design lead andor lag compensators. Pdf this paper introduce the lead,lag,laglead compensator design of root locus using single composite matlab programme.
Margins 12 mechanistic lead compensation design with matlab. Lead compensators design using frequency response techniques. For those who have followed my previous posts will know by now what the. Phase lead compensator design using bode plots the gmu ece. There are three generic compensators as phase lab compensator phase lead compensator notch filter phase lead compensator transfer function phase contribution example open loop transfer function of a system is design a control system for the following specifications 1. A firstorder phase lead compensator can also be designed using a frequency reponse approach. The examples and plots presented here are all done. The paper describes the result comparisons that were developed for the phase lead compensator design using nichols chart and bode plots. Introduction to matlab lag compensator with bode plot lag compensator with root locus so far we have seen the design of lag compensators, now we move on to lead compensators which help in improving the transient response. Then we present a design technique for the lead compensator by use of the bode diagram. A lead compensator design example is worked based on improving transient time domain specifications. The implementation of classical experiments as matlab m files is described. A lead compensator in frequency response form is given by the following. Design of a lead compensator with root locus in matlab.
Control system design by frequency response using matlab. If damping ratio alone is given then draw the root locus and draw line from origin at an angle to intersect the root locus, the point of intersection is the dominant pole. The implementation of classical experiments as matlab mfiles is described. Designing digital lead and lag compensators using the. Dominant pole compensator in this case the pole is at zero frequency and so the transfer function is that of an integrator. Designs are based on a target gain cross over frequency and a target phase margin. Lead compensator design contd to compensate angle deficiency, design a lead compensator cs satisfying re im desired pole there are many ways to design such cs. We will start from the frequency domain design using bode plot. Analyze toque speed characteristics of dc and ac servomotors. Shows how matlab tools can be used quickly and efficiently to implement, and illustrate, the mechanistic design procedure for a lead compensator. Design via root locus elec304alper erdogan 1 1 lecture.
May 22, 20 designing a lead compensator with bode plot. State space root locus sketching rules negative feedback rule 1. This video walks through a phase lead compensator example using the bode plot method. Lead compensator example draw bode plot of l1s using approximated bode plot pm is found to be 17o.
Pdf root locus, lead, lag, lag lead commentator using matlab with. The lead compensator zero location is placed over the left. Validate your compensator design by simulating the nonlinear simulink model with the tuned controller parameters. This paper introduce the lead,lag,lag lead compensator design of root locus using single composite matlab programme. Magnitude and phase plots for a typical lead compensator. Analyze and interpret stability of the system through root locus, bode plot and nyquist plot. The implementation of classical experiments as matlab m. If we want to add a dominating zero for compensation in control system then we have to select lead compensation network. A comparative analysis of pid, lead, lag, leadlag, and. The phaselead compensator design aims at finding the parameter.
Here it is how to perform the lead compensation using matlab tool. My philosophy on lead compensator design is to place the compensator zero in the splane at about onethird the. Control system design using bode plot lead, lag and leadlag controllers. Pdf a root locus design matlab simulation lead and lag compensator to improve the steady state error and overshoot with settling time find. Consider of lead compensator having the following transfer function. Design of phase lead and phase lag compensator for pitch. The lead compensator is an electrical network which produces a sinusoidal output having phase lead when a sinusoidal input is applied. Run matlab and change your workspace to your folder on the c. Root locus lead compensator design example polezero.
This will be a series of posts where i will be dealing with control system compensator design using matlab. Lec41 compensator design using frequency response plots. In the editor, you can adjust the openloop bandwidth and design to gain and phase. A system which has one pole and one dominating zero the zero which is closer to the origin than all over zeros is known as dominating zero. Design analysis of phase lead compensation for typical. Design example 1 design a lead compensator for the digital control system below so that the pm is 50, the gm is at least 10 db. Using control system designer, you can manually edit compensator dynamics to achieve your design goals. The instantaneous gain of the compensator is 1, and the dc gain is equal to 1z1p, where z is the zero and p is the pole of the compensator. Tuning of a feedforward laglead secondorder compensator. I took one whole day to figure out how to write a program to designa lead compensator with rot locus in matlab. In the pid tuning dialog box, in the specifications section, select the following options. Design three lead compensators for the system to reduce. Using matlab scilab a simulation of a typical second order system and determination of step response and evaluation of time. Leadlag compensators example with design so that dominant closed loop poles are at the sse is 0.
Li, sheng and chen 2010 derived the impulse response of the distributed order leadlag compensator using matlab and compared with the numerical inverse laplace transformation method 10. Finally, the result of phase lead and phase led compensator is presented by using matlabgui. Since detailed discussions on the design of lead and lag compensators individually have been presented in my notes1 phase lag compensator design using bode plotsandphase lead compensator design using bode plots, theses notes will concentrate on the use of those two designs together. Compensation in control system lag lead compensation. Method design a lead compensator to place the dominant poles at the desired places while neglecting the effects of the lag compensator. In matlab a phase lead compensator in root locus form is implemented using the following commands where kc, z, and p are defined. Analysis of phase lead compensator design for laser. Bode diagram design is an interactive graphical method of modifying a compensator to achieve a specific openloop response loop shaping. Pdf computer aided design of lead compensator using root. Then all of design parameters of compensator and design steps are implemented using matlab without manual calculation except the gain corresponding to get. Design compensator using automated pid tuning and graphical bode design.
In this particular system the feedforward path includes only the transer function. Design lag, lead, leadlag compensators and verify experimental results using matlab. Compensator design lead compensators lag compensators leadlag compensators ee3cl4. There is nothing you have to do with this simulink model other than build once. Lead example the process is slightly simpler if we target the lead compensator design at a particular desired. Adding a phaselead compensator to an existing openloop transfer function can increase the phase margin, the bandwidth, andor the gain margin. Plot the closed loop system performance using the feedback and step function in matlab.
In particular, you can adjust the compensator gain, and you can add the following compensator dynamics. In this section we introduce their structures and indicate their main properties. This example shows how to design and analyze a controller for multiple plant models using control system designer. Leadlag compensator using either root locus or frequency response. They are known as pd, pi, pid, phaselag,phaselead,and phaselagleadcontrollers. Design a lead compensator to place the dominant poles at the desired places while neglecting the effects of the lag compensator. Design of lead compensator for process control using. To tune the compensator using automated pid tuning, click tuning methods, and select pid tuning. The minor loop is designed to change the open loop poles and open loop transientresponse. You should see on the encoder scopes that the square wave reference signals appear. It can be very challenging to reguate such a system.
The proposed phase lead and phase lag compensator design can be used for any system that the mathematical model have been known to meet desired specifications. Design the lag compensator to satisfy the improvement in steady state performance. Fall 2008 16 lead compensator positive angle contribution triangle re test point im sp1z1. Depending on the effect desired, one or more lead and lag compensators may be used in various combinations. In matlab a phaselead compensator in root locus form is implemented using the following commands where kc, z, and p are defined.
First design the minor loop then design the major loop. The comparative analysis is conducted with respect to different time domain specifications like gain, percentage overshoot, settling time, and rise time. An introduction to compensator design with matlab geek peek. Setiawan 2010 presented the evaluation of closedloop controller responses of a tini sma gripper using lag, lead and laglead compensators. This document is intended to give you an example of using matlab and root locus to design controllers compensators in the zplane. To open the compensator editor dialog box, in control system designer, in an editor plot area, rightclick and select edit compensator. Consider compensation as adding poles and zeros to feedback section for the equivalent system. Design of lead and lag compensators using frequency domain techniques tim davidson mcmaster university.
Compensator design to improve transient performance using. Lead compensator design take 1 to design a lead compensator, the first trick is to determine which pole to cancel. The general transfer function of the lead compensator is t a s t s t g c s. Compensator design to improve transient performance using root locus prof. Compensator design for a set of plant models open script this example shows how to design and analyze a controller for multiple plant models using control system designer. Using these editors, you can interactively tune the gain, poles, and zeros of the compensator, while simultaneously visualizing the effect on the set of plants. Design of lead compensator for process control using multisim sumant kumar, vinod k. A typical laser guided missile control has been discussed.