Familiarizing the students with the components of modern machining control systems. Analysis of feedforward and feedback control for one or more machine axes. Machining process monitoring and control (optimal, adaptive).

Student responsibilities:

Grading and evaluation of student work over the course of instruction and at a final exam:

Active participation during lecturers or exercises - 10%; Term work - 40%; Oral exam- 50%

Methods of monitoring quality that ensure acquisition of exit competences:

Continuous discussions and monitoring of student work on lecturers and exercises. Consultations during the term.

Upon successful completion of the course, students will be able to (learning outcomes):

Upon successful completion of this course student will be able to: - Define elements of the machine tool CNC control system, - Compare different types of electrical motor drives which are used in the construction of machine tools, as well as different types of position and speed sensors, - Identify machine tool feed drive dynamic model - Determine advantages and disadvantages of different speed and position control techniques, - Choose accordingly the type of electric motor drive and control strategy (with adaptation of control parameters), - Choose and implement adequate sensors, signal processing and decision algorithms for the purpose of machining process monitoring, - Suggest adequate process level control strategy (adaptive and optimal).

Lectures

1. Basics of Numerical control (NC) and Computer numerical control (CNC) systems. Linear interpolators.

2. Open and closed loop control of one machine axis.

3. NC programming control modes.

4. Closed-loop dynamics of one machine axis.

5. Sensors in feedback control.

6. Hardware and software type circular interpolators.

7. Two-Axes machine control system. Open and closed incremental control loops.

8. Closed-loops in continuous machining.

9. Mathematical analysis of the closed-loop dynamic.

10. Synthesis of the closed-loop control.

11. Machining contour error of two-axes system.

12. Contour error in corner machining.

13. CNC systems. CNC controllers.

14. Impulse techniques and discrete signals in the synthesis of the feedback control.

15. Optimal and adaptive machine control systems.

Exercises

1. Continuous and point-to-point programming.

2. Control parameters calculation for step and DC motors.

3. NC programming tools.

4. Dynamical model of step and DC motor of one machine axis.

5. Encoders, resolvers, inductosyns and tachometers.

6. Calculation of circular interpolator errors. Tustin method.

7. Examples of open and closed incremental control loops.

8. Examples of closed-loops in continuous machining.

9. Calculation of closed-loop control parameters.

10. Examples of the closed-loop control synthesis.

11. Calculation of machining contour error of two-axes system.

12. Calculation of contour error in corner machining.

13. Structural schemes of CNC systems and controllers.

14. Schemes of impulse techniques and discrete signals in the synthesis of the feedback control.

15. Examples of optimal and adaptive machine control systems.

Compulsory literature:

Altintas, Y.: Manufacturing Automation: Metal Cutting Mechanics, Machine Tool Vibrations, and Cnc Design, Cambridge University Press, 2012.
Suh, S.-H., Kang, S.-K., Chung, D.-H., Stroud, I.: Theory and Design of CNC Systems, Springer-Verlag London, 2008.
Koren, Y.: Computer Control of Manufacturing Systems, Mc Grow-Hill Book Co., London, 1986.
Novaković, B.: Metode vođenja tehničkih sistema, Školska knjiga, Zagreb, 1990.
Desrochers, A.: Modelling and Control of Automated Manufacturing Systems, IEEE Comp. Soc. Press, Washington, 1990.

Recommended literature: