Implementation of PV and PIV Control for Position Control of Servo Motor

Transcription

1 IJSRD - Internationa Journa for Scientific Research & Deveopment Vo. 5, Issue 1, 2017 ISSN (onine): Impementation of PV and PIV Contro for Position Contro of Servo Motor J.Priya 1 R.Rambrintha 2 1,2 Assistant Professor 1,3 Department of Eectronics and Eectrica Engineering 2 Department of Eectronics and Instrumentation Engineering 1,2 Bannari Amman Institute of Technoogy Abstract the objective of the paper is to impement PV and PIV contro for position contro of servo motor. A Quanser servo pant modue and dspace software with the DS1104 R&D controer board is used in the experiment to derive transfer function of servo motor that describes the oad shaft position with respect to the motor input votage using frequency response method and to deveop a feedback system that contros the position of the rotary servo pant. Key words: Quanser servo pant (SRV02); Frequency response method (FM); dspace R&D controer board (DS1104); Proportiona Veocity (PV); Proportiona Integra Veocity (PIV) oad gear. The different options enabes users to work with both anaog and digita position measurements as we as measuring the anguar rate using a tachometer. The SRV02 incorporates a Fauhaber coreess DC motor that is high efficiency and ow inductance motor with a sma rotor inductance. Thus it can obtain much faster response than a conventiona DC motor. The Quanser servo motor can be used stand-aone for severa experiments but it aso serve as a base component for severa add-on modues. I. INTRODUCTION Generay in a universities in India and wordwide Quanser servo pant with the Quanser Q4 or Q8 board and Wincon software is used to construct aboratory experiment as discussed in [1] and [2]. Since there are some imitations in using this software it is proposed to use the dspace software with the DS1104 R&D controer board to obtain better position and speed contro of the pant with the hep of [3] and [4]. The Quanser servo pant consists of a DC motor and interna gear boxes which makes it suitabe for contro of noninear systems. Since the pant is used for contro objective, accurate modeing of the system is mandatory. In order to find the experimenta transfer function of the SRV02 an experimenta set up is deveoped which consists of dspace software, DS1104 interface board and UPM power suppy modue. The UPM provides continuous input to the SRV02. The Quanser servo pant is interfaced with the PC which consists of the dspace software, using the DS1104 R&D controer board, CP1104 connector pane and a UPM power suppy modue as in [4]. The transfer function of the Quanser servo motor is determined using Frequency domain method, which is a grey box method of modeing a system with the hep of [5], [6] and [7]. The resuts obtained using both methods are tabuated with the theoretica transfer function of the Quanser servo motor. Tracking the position of DC servo motor is performed and PV, PIV contro responses are obtained. II. QUANSER SERVO PLANT A. SRV02 description: The SRV02 figured in Fig. 1 is provided with DC motor that is encased in a soid auminum frame and equipped with a panetary gearbox. It comes with a potentiometer sensor that can be used measure the anguar position of the oad gear. The SRV02 device can aso be fitted with an encoder for digita measurement and a tachometer to measure the speed of the Fig. 1: Top and Front view of Quanser servo pant B. UPM Power suppy modue UPM 1503 shown in Fig. 2 is used to provide continuous input to the Quanser servo pant. The UPM ampifies the input signa from the DS1104 interface board and provides an input of 12v to the Quanser servo pant. A rights reserved by 151

2 Impementation of PV and PIV Contro for Position Contro of Servo Motor (IJSRD/Vo. 5/Issue 1/2017/041) Fig. 2: Front view of UPM 1503 III. INTERFACE SRV02 WITH DSPACE SOFTWARE The dspace is a rea time simuation system that consists of a set of hardware and software as shown in Fig. 3. Initiay the dspace software shoud be instaed in the system. An interface board wi be provided with the hardware components which have to be paced in the PCI sot of PC. Through this interface board the CP1104 connector pane wi be connected for connection between the externa hardware which is shown in Fig. 4. Fig. 3: Experimenta setup of pant with dspace A. Connecting DC Motor To UPM: To Load cabe : This connector uses a 6 pin DIN / 4 pin DIN, and goes from the ampifier to the actuator in the pant. One end of the cabe has six pins, and the other has four so it is matched appropriatey. This cabe then transfers power to the pant and the anaog contro input to the pant. S1 & S2: A 6 pin-mini-din to 6 pin-mini-din is connected between the motor S1& S2 connector and the UPM. This carries the response of the servo motor to UPM. S3: This is aso connected by the 6 pin-mini-din to 6 pin-mini-din which carries the tachometer reading. Fig. 4: Experimenta set up of SRV02 B. Connecting UPM and DS1104 Board: From D/A: A 5 Pin Din-mono / RCA cabe is used to connect one anaog output from the dspace board to the pant. This cabe wi be referred to as the D/A cabe, and it is back. The RCA termination is hooked up to the data acquisition board and the 5 Pin Din-mono is connected to the power modue. To A/D: A 5 Pin Din-stereo / 4 x RCA cabe is used to connect a 4 of the anaog inputs to the dspace card. The cabe is known as To A/D cabe, and it is a back cabe. The RCA termination (ike for your stereo) is going to be connected to the data acquisition board and the 5 Pin Din-stereo is going to be connected to the power modue. C. Connecting CP1104 to DS1104 Board: The anaog input to the SRV02 is given from DACH1 pin in the CP1104 board. This signa wi be present in the P1A 31 pin of DS1104 board and from the anaog output #0 the signa is given to the From D/A connector. The anaog output from the SRV02 is given to UPM through S1 & S2 signas. This signa is given to the DS1104 board in anaog input port. The anaog signa is taken from the pin P1A50 and P1B50 in the interface board and given to the ADCH4 and ADCH5 channes. To get the tachometer signa the pin 33 of P1A is connected with ADC6 channe. From this channe the speed of the Quanser servo motor wi be recorded which wi be usefu for deriving the experimenta transfer function of the system. IV. THEORITICAL TRANSFER FUNCTION OF QUANSER SERVO MOTOR The anguar rate (s) of the SRV02 oad shaft with respect to the input motor votage V m (s) can be described by the foowing first order transfer function, (s) (1) Vm (s) s 1 The transfer function mode is derived anayticay from eectrica and mechanica equation of the motor which is obtained from first principes. A rights reserved by 152

3 Impementation of PV and PIV Contro for Position Contro of Servo Motor (IJSRD/Vo. 5/Issue 1/2017/041) Thus the Steady state gain of the system is, Time constant is, rad K sv s V. MODELING OF SRV02 PLANT EXPERIMENTALLY A inear mode of the system can aso be determined by experimenta approach. The idea is to observe how a system reacts to different inputs and change structure and parameters of a mode unti a reasonabe fit is obtained. The inputs can be chosen in many different ways and there is a arge variety of methods. The two methods, Frequency response and Bumptest method are discussed. A. Frequency response method: In this method a sine wave input with a set ampitude and frequency is given to the servo motor. The output wi be sinusoid with the same frequency but with different ampitude. By varying the frequency of the sine wave and observing the resuting outputs, bode pot of the system can be obtained. From bode pot the steady state gain, i.e. the DC gain, and the time constant of the system can be determined. 1) Rea time experiment: A sine wave of varying frequency is fed to the DC motor as shown in Fig. 5 and the resuting maximum speed of the shaft is cacuated. Bode pot of the system is constructed using the data coected from the contro desk which is shown in Fig. 6 and the mode parameters are cacuated. In the Simuink ibrary, the signa generator bock is seected and foowing parameters are ensured: Wave form: sine Ampitude: 0.0 Frequency: 1.0 Units: Hertz The Ampitude (V) sider gain is set to 0.0V. The offset (V) bock is set to 0.2V. Input is given to the DC motor through DS1104 DAC channe1. Response from the motor is obtained from DS1104 ADC channe6. Speed of DC motor is obtained from DS1104 ADC channe 7. Now the MATLAB fie wi be transferred to dspace environment by seecting incrementa buid option. When this input is given to the SRV02 unit it shoud begin rotating in one constant direction. Then the offset is set to 0.0V and sider gain is set to 0.2V. Fig. 5: MATLAB diagram for modeing the DC servo motor Fig. 6: Frequency response of system 2) Response of the system: By varying the frequency of th sine wave input maximum speed of motor shaft is cacuated and corresponding gain vaues are obtained which is given in tabe 1 : Freq (Hz) Input (V) Maximum Load Speed (rad/s) Gain: (rad/s/v) Gain: (rad/s/v,db) Tabe 1: Coected frequency response data 3) Transfer function: Magnitude of Frequency response of SRV02 pant transfer function,: (0) G w, v (0). Vm (0) where, is the frequency of the motor input votage. Thus for f=0hz the maximum oad speed is and the votage is 0.2V. Therefore Gain is, A rights reserved by 153

4 Impementation of PV and PIV Contro for Position Contro of Servo Motor (IJSRD/Vo. 5/Issue 1/2017/041) rad G w, v (0) sv The Gain in db is, G (0) 20og10( ) 4.52 db. w, v The -3dB Gain is, db G w, v (ω c ) 1.52 db. db From the bode pot the cut-off frequency is f c=6.6 Hz. c=2πf c. rad ω c s Time constant is, 1 τ. ω c τ 0.024s. Thus the transfer function of the system is, (s) V (s) 0.024s 1 m VI. SRV02 POSITION CONTROL A. SRV02 Position Contro Specifications: The time domain specifications for controing the position of the SRV02 oad shaft are, e ss=0 (11) t p=0.2[s] (12) PO=5[ % ] (13) Thus when tracking the oad shaft reference, the transient response shoud have a peak time ess than or equa to 0.2 seconds, a over shoot ess than or equa to 5% and the steady state response shoud have no error. Cacuate the maximum overshoot of the response (in radians) given a step set point of 45degrees, or π θ d t (14) 4 Using the expression, PO θ t θ t 1 (15) p d 100 The maximum overshoot with a step response of, θ d (t) 0.785[rad] (16) B. PV Contro Design: θt p 0.823[rad] (17) 1) Cosed Loop Transfer Function: The proportiona-veocity (PV) Compensator used to contro the position of the SRV02 has the structure, d θ t θ t k θ t V (t) k (18) m p d v dt Where k p is the proportiona contro gain, k v is the veocity contro gain, t is the set point of reference oad d ange, and t is the measured oad shaft ange, and V m is the SRV02 input votage. 2) Matab Mode for Position Contro of the Servo Motor Fig. 7: Mode for PV Contro This contro mutipies error by proportiona gain and differentiates the output which gives veocity. It is then mutipied by veocity gain and added for generating contro input. Response of PV Contro Fig. 8: PV contro Response of PV Contro In dspace PIV Contro Fig. 9: PV contro in dspace Fig. 10: PIV contro A rights reserved by 154

5 Impementation of PV and PIV Contro for Position Contro of Servo Motor (IJSRD/Vo. 5/Issue 1/2017/041) Adding an integra contro can hep to eiminate any steady state error. It aso suppress spike due to veocity feedback. System response can be improved by integrating the error. Response of PIV Contro Fig. 11: PIV contro Response Of PIV Contro In dspace Fig. 12: PIV contro in dspace VII. CONCLUSION The experiment is carried out to check the response of the PV and PIV controer for position contro of servo motor, which had greaty minimized the steady state error and peak over shoot of the Quanser Servo motor. Input to the system is given through the DS1104 board and the response of the system is recorded using the dspace software. The interfacing procedure of SRV02 pant with UPM, dspace hardware and software is ceary expained. Since the Quanser Servo motor is a non-inear system theoretica design of transfer function and controer which is a back box approach wi not support in accurate contro of the pant. The transfer function that is derived practicay is utiized to deveop the PV and PIV controer for position contro of the Quanser servo motor.thus from the recorded data transfer function of the Quanser servo pant is experimentay determined. The response of PV and PIV contro were compared Description Symbo Vaue Unit Nomian Vaues Open Loop Steady-State K 1.53 Rad/S/V Gain Open Loop Time S Constant Frequency Response Modeing Open Loop Steady-State K Gain e,f 1.52 Rad/S/V Open Loop Time Constant Tabe 2: Modeing resuts summary e, f S ACKNOWLEDGMENT The authors wish to thank the Coege Management and Principa for being a constant source of encouragement and providing the faciity to utiize the dspace S/W & H/W and Quanser make modue in Thiagarajar Coege of Engineering, Madurai. REFERENCES [1] Quanser consuting, QUANSER DS1104 INTERFACE BOARD, [2] Quanser. SRV02 MODELING USING QUARC. [3] Nicanor Quijano and Kevin M. Passino, Modeing and System Identification for a DC Servo, Deptartment of Eectrica Engineering, The Ohio State University, March 29, [4] Nicanor Quijano and Kevin M. Passino, Interfacing dspace to the Quanser Rotary Series of Experiments (SRV02ET), Dept. of Eectrica Engineering, The Ohio State University, March 22, [5] Xiaoou Li and Wen Yu, Synchronization of Ba and Beam Systems with Neura Compensation, Internationa Journa of Contro, Automation, and Systems,pp ,2010. [6] J. Hauser, S. Sastry, and P. Kokotovic, Noninear contro via approximate input-output inearization: ba and beam exampe, IEEE Trans. on Automatic Contro, vo. 37, no. 3, pp , [7] Sau Jimenez and Wen Yu, Stabe Synchronization contro for two Ba and Beam systems, Department of Automatic contro, ICEEE, [8] N. Quijano, K. M. Passino, EE758 Contro Laboratory II: Lab4( htm) [9] Quanser. SRV02 POSITION CONTROL USING QUARC. A rights reserved by 155