{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

motors080904 - Motors and Position Determination...

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Motors and Position Determination Motors and Position Determination L17 6.111 Fall 2003 – Introductory Digital Systems Laboratory
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
x Controlling Position Controlling Position Feedback is used to control position. Measure the position, subtract a function of it from the desired position and then use this resulting signal to drive the system towards the desired position. This is negative feedback. The natural frequencies of the feedback system are the “zeros” of 1 + G(s)H(s). z The total system is unstable if these “zeros” are in the right half plane (RHP). With 180 degrees phase shift, “negative” feedback becomes “positive” feedback. z So we want these “zeros” to be in the left half plane (LHP). z Putting an integrator into H(s) drives steady state error to zero. z But high order systems are more likely to have RHP zeros. z Time delay and high gain lead to RHP zeros. H(s) G(s) + + y Y(s) H(s) = X(s) 1 + G(s) H(s) L17 6.111 Fall 2003 – Introductory Digital Systems Laboratory
Image of page 2
Servos Servos We can control parts of the servo, but the system dynamics is often a part we can’t control. The system dynamics results from masses. springs, losses, etc. Likely, we will implement servos as digital systems. Digital systems are more flexible to design. z They are more repeatable; they are not subject to gain drift. z We can use as many bits as we like so we can keep the computation noise small. Digital systems can have significant delays. z These delays are sometimes fixed, but are sometimes stochastic. Position + + x y Output Position G(s) C(s) A(s) Measurement System Dynamics Controls Likely boundary of Desired digital system L17 6.111 Fall 2003 – Introductory Digital Systems Laboratory
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Analog Position Measurements Analog Position Measurements Voltage is proportional to position.
Image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern