Title on all pages DC motor modeling with hands on experiments on DSP2 learning module (introductory lecture to mini project) Doc.dr. Suzana Uran Address : Smetanova 17, SI-2000 Maribor, Slovenia; University of Maribor, Faculty of Electrical Engineering and Computer Science

Title on all pages Contents About DSP2 learning module DC motor modelling –hands on exercise: current controlled DC motor model (we look for a model of current control loop ) Conclusion

Title on all pages DSP2 card Exchangeable Control Plant Control system: DSP2 learning module

Title on all pages DSP2 card: short description Signal processor TI TMS320C32-60, 3 fast analog inputs 12 bit (2.6us conv. time) 8 MUX analog inputs 12 bit, 1 analog bipolar output(12 bit)/2 unipolar outputs 1 PWM output (3 phase) 1 input for incremental encoder 3 digital outputs and 1 digital input (isolated) RS 232 duplex communication port

Title on all pages Control plant: DC/AC motor H-bridge DC motor

Title on all pages Control plant: Buck converter buck

Title on all pages RC oscilator: ADDA+RC control plant RC control plant also REMOTE experiment!

Title on all pages DSP2 module: Rapid Control Prototyping MATLAB/SIMULINK and DSP Terminal on Personal computer

Title on all pages SIMULINK libraries for DSP2 learning module Embedded Target for DSP-2 board DSP2 learning module DSP blockset Standard SIMULINK libraries DSP2_Library_for_Simulink.pdf

Title on all pages Modelling of DC motor current control loop Hands on experiment: Build a MATLAB/SIMULINK block scheme for open loop control of current controlled DC motor (ESCAP 28D2R-219P) using DSP2 learning module! Measure motor speed with incremental encoder.

Title on all pages DC motor, load, encoder data DC motor ESCAP 28D2R-219P with incr. encoder. Nominal voltage 12 VTorque constant 19.5 mNm/A Nominal current 1.5 ARotor inertia1.76*10 -6 kgm 2 Nominal speed 5000 rev/min Load inertia7.56*10 -6 kgm 2 Incremental encoder 144*4=576 p/rev

Title on all pages Getting started: DSP2 learning module In MATLAB6p5/work directory create a new directory named: VILLACHvisit Run MATLAB6p5 and go to VILLACHvisit directory In MATLAB command window write command: dsp2lib DSP2_Library_for_Simulink.pdf

Title on all pages Getting started In the new opened window ( see figure below) double click New Model button and choose new file name!

Title on all pages Getting started A new SIMULINK file for work with DSP2 learning module is opened with 3 buttons left above. Now you can start building SIMULINK block scheme.

Title on all pages Getting started Getting started In DSP2 learning module library find blocks with name DCMOT choose block DCMOT tokovna regulacija (DCMOT TOKREG Ia – motor current control loop ) and put it in your SIMULINK scheme choose block DCMOT meritev hitrosti (DCMOT OMEGA – motor speed measurement) and put it in your SIMULINK scheme

Title on all pages Getting started In menu of your file choose: Simulation/Simulation Parameters/Real-Time Workshop For DSP-2 options 2 set: 576 number of lines per revolution for Incremental encoder

Title on all pages Getting started Getting started In Embedded Target for DSP-2 board library find block To Terminal – it is a block for data visualisation on your PC use three blocks To Terminal as shown on next slide In Embedded Target for DSP-2 board library find block From Terminal – it is a block for data input from keyboard of your PC use two blocks From Terminal as shown on next slide

Title on all pages Getting started Build SIMULINK block scheme below:

Title on all pages Getting started Set parameters on the left for Pulse Generator block

Title on all pages Getting started Double click Edit Parameters (blue button) Enter definitions for: –T = 200e-6; % sampling time –amp (choose – carefully consider) –per (choose – carefully consider) –offset (choose – carefully consider) Double click Update Parameters (blue button) Switch on DSP2 learning module and double click Build (blue button)

Title on all pages after code buiding and download to DSP2 the DSP Terminal program starts. FIRST set Ioff as below (middle value to 0) Getting started

Title on all pages Getting started After setting ENABLE=1, and selecting Ia, IaREF to view we get:

Title on all pages Getting started Did you get the same response? What happens if we choose offset=0? WHY? Determine the order and parameters of the model for the current control loop ! If there is enough time left find the speed response of DC motor!

Title on all pages Motor speed response/Simulink input signal IaREF Speed response

Title on all pages Conclusion Current control loop is modelled as 1 st order system. - KMKM K T, T T MdMd mm 1/J C I aREF K T = 1, T T = 0.9 ms J C = kgms -2 K M = Nm/A

Title on all pages Motor speed measurement Motor speed measurement is obtained from position measurement of incremental encoder by differenciation  is very noisy. To filter out the noise we use : 2.nd order Butterworth filter with f cutoff = 200 Hz.