department of electrical engineering southern taiwan university a novel motor drive design for...

Department of Electrical Engineering Southern Taiwan University

Department of Electrical Engineering Southern Taiwan University

A Novel Motor Drive Design for Incremental MotionSystem via Sliding-Mode Control Method

A Novel Motor Drive Design for Incremental MotionSystem via Sliding-Mode Control Method

Student: Cheng-Yi Chiang Adviser: Ming-Shyan Wang Date : 31th-Dec-2008

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 52, NO. 2, APRIL 2005

Chiu-Keng Lai and Kuo-Kai Shyu, Member, IEEE

Department of Electrical Engineering Southern Taiwan UniversityDepartment of Electrical Engineering Southern Taiwan University

Abstract

INTRODUCTION

FIELD-ORIENTED PMSM

INCREMENTAL MOTION CONTROL OF PMSM

A. Velocity Control Mode

B. Position Control Mode

C. Velocity Control Mode

D. Position Control Mode

SIMULATION RESULTS

EXPERIMENTAL SETUP AND RESULTS

A. Experimental System Setup

B. Experimental Results

CONCLUSION

REFERENCES

Outline


Abstract

This paper proposes a particular motor position control drive design via a novel sliding-mode controller.

The newly designed controller is especially suitable for the motor incremental motion control which is specified by a trapezoidal velocity profile.

The novel sliding-mode controller is designed in accordance with the trapezoidal velocity profile to guarantee the desired performance.

A motor control system associated PC-based incremental motion controller with permanent-magnet synchronous motor is built to verify the control effect.

The validity of the novel incremental motion controller with sliding-mode control method is demonstrated by simulation and experimental results.


INTRODUCTION

The control of motors used in high-performance servo drives requires the prescribed torque accuracy, velocity, and/or position for all operating conditions being achieved.

To obtain the desired performance, a precise system model is needed.

It is difficult to construct because of the inherent nonlinearity of

friction and dead zone, the parameter variations due to temperature,

the uncertain external disturbances, and so on.

PI-type control methods are not robust enough to accommodate the

variations of external disturbances, parameters, and perturbations

during operation


INTRODUCTION

Variable-structure control (VSC) or sliding-mode control (SMC) has been known as a very effective way to control a system because it possesses many advantages.

such as insensitivity to parameter variations, external disturbance

rejection, and fast dynamic responses.

VSC has been widely used in the position and velocity control of dc and ac motor drives.

The system dynamics of a VSC system can be divided into two phases: the reaching one and the sliding one.

The robustness of a VSC system resides in its sliding phase, rather the reaching phase.


INTRODUCTION

This paper proposes a multisegment sliding-mode- control-method-based motion control drive design in accordance with a trapezoidal velocity profile.

It also shows that the reaching phase existing in the conventional VSC does not exist in the designed multisegment sliding-mode controller.

The robustness of the controlled system can be assured from start to finish.


FIELD-ORIENTED PMSM

, the d, q-axes stator voltages.

, the d, q-axes stator currents.

, the d, q-axes inductance.

, the d, q-axes stator flux linkages.

, the stator resistance and inverter frequency.

the equivalent d-axes magentizing current.

the d-axis mutual inductance.

.fdmdddd ILiL

dqsqsqdq iLwiRidt

dLv

qqsdsddd iLwiRidt

dLv (1)

(2)

qqq iL (3)

(4)

dv qv

di qi

dL

d qqL

sR sw

fdI

mdL


FIELD-ORIENTED PMSM

the pole number of the motor.

the rotor velocity.

the rotor angular displacement.

the moment of inertia.

the damping coefficient.

the external load.

The inverter frequency is related to the rotor velocity as

qdqdqfdmde iiLLiILpT )(2

3

mm w

dt

d

Lemmm

m TTwBdt

dwJ (7)

(6)

(5)

.ms ww LT

mB

mJ

m

mw

p


FIELD-ORIENTED PMSM

Since the magnetic flux generated from the permanent magnetic rotor is fixed in relation to the rotor shaft position.

The flux position in the coordinates can be determined by the

shaft position sensor.

qd -


FIELD-ORIENTED PMSM

The PMSM used inthis drive system isa threephase four-pole 750-W 3.47-A 3000-r/min type.

Fig.1. (a) System configuration of fiele-oriented synchronous motor.


FIELD-ORIENTED PMSM

Fig.1. (b) Simplified control

system block diagram.

vKT te

mmp BsJ

SH

1

)(

,/mN2.2 vK t 2s/mN0021.0 mJ

m/sN0015.0 mB

v

(8)

(9)

is the inverter torque command which is proportional to the –axis current, .q



The rotor dynamics and the torque equation of PMSM given

in (6)-(8) are rewritten as follows:

mm w

dt

d

m

L

m

em

m

mm

J

T

J

Tw

J

B

dt

dw

.vKT te (10)



The incremental motion control is to move an object at rest at time to a fixed desired position at time , and then stop it.

The control process is subjected to the desired velocity and acceleration.

Therefore, the incremental motion control is performed under velocity

control in obedience to a desired velocity profile, whereas stopping is

done by position control mode.

d dt0t



One first has to select a velocity profile which rapidly changes the load position in discrete step.

The velocity profile should satisfy the motion constraints of the system.

The velocity and acceleration limitations are generally taken into

consideration for the determination of velocity profile.

To satisfy the velocity and acceleration limitations, a trapezoidal

velocity profile is usually used.

The object here is to design a multisegment sliding mode controller

according to the trapezoidal velocity profile



Fig.2. Trapezoidal velocity profile for incremental motion control.



With a specified rotor position , which is assumed to be a constant within

the control process, one first defines the position error and its derivative as

Combining (11) with (6) and (7), one obtains

Note that (12) and (13) hold because the specified position is

a constant.

d

m

dm

wx

x

2

1 (11)

(12)

(13)

d

21 xx

m

L

m

e

m

m

J

T

J

Tx

J

Bx 22



According to the error dynamical equations (12) and (13), a multisegment SMC is proposed to drive the motor from initial position

to the specified position according to the trapezoidal velocity profile given in Fig. 2.

The multisegment SMC is composed of two modes, the velocity

control mode and the position control mode.

The velocity control mode is used to drive the rotor to the desired

position and the position control mode is used to hold the rotor at the

desired position

d0



1) Acceleration segment

: is the initial position error.

To check the motor acceleration on

Thus, the motor dynamics on the acceleration segment (14) have the desired constant

acceleration .

1s

02

110

22

111 xxxs

d(14)

dxxx 010

01 s

d1

21 xx

dt

dwx m

d 12

01

221

11 xxx

dt

ds

d



2) Run segment

3)Deceleration segment 3s

022 dwxs

2s

02

1 22

313 xxs

d (16)

(15)

03 s

dt

dwx m

d 32

02 s

dm wxw 2


B. Position Control Mode

In the position control mode, the following position control segment is proposed:

where is a positive constant.

Lemma [6]–[8]: If a switching surface of the controlled system satisfies the following sliding condition:

Where and are parameters to be designed in accordance with the corresponding sliding segment, and has been defined in (8).

01424 xcxs (17)

4c

)(ts

0ss (18)

vKT te

)( 221 xhhK t (19)

2h1h

tK


C.Velocity Control Mode

First, the acceleration segment is considered. The parameters and in (19) will be designed to satisfy the sliding condition of the acceleration segment

where , and is the sign function.

1h 2h

011 ss (20)

)1

( 221

1111 xxxsssd

.)(1

1 22121

21

Lttm

md

TxhKhKxBJ

xs

(21)

)sgn()sgn( 12111 dxsh

)sgn()sgn( 1112 dsh

(22)

(23)

tmtLmd KBKTJ /,/)( 111 )sgn(


C.Velocity Control Mode

where and

where and

033 ss

)sgn( 221 sh

)sgn( 2222 xsh

tL KT /2

022 ss

)sgn()sgn( 32331 dxsh

)sgn(sgn 3332 dsh

tmdL KJT /( 33 ./3 tm KB

./2 tm KB

(23)

(24)

(25)

(27)

(26)

(28)


D.Position Control Mode

Where

and

044 ss (29)

02211 vxhxhv

)sgn( 1441 xsh

)sgn( 2442 xsh

).sgn( 400 sTv

,/)(,0 444 tmm KcJB ./0 tL KTT

(30)

(31)

(32)


Position Control Mode

Fig. 3. Multisegment SMC-based incremental motion control for PMSM system


Fig. 4. Simulated results of multisegment sliding-mode motion control.

(a) Velocity responses.

(b) Position responses. (c) Control output.

SIMULATION RESULTS


Fig. 5. Trajectories of four switching functions of multisegment sliding- mode controller.

SIMULATION RESULTS


Fig. 6. Simulated results of conventional sliding-mode

motion control.

(a) Velocity responses. (b) Position responses. (c) Control output.

SIMULATION RESULTS


Fig. 7. Simulated results with external load 2 N m. ‧

(a) Velocity responses.

(b) Position responses.

(c) Control output.

SIMULATION RESULTS


Fig. 8. Simulated results with external load 2 N m and‧ mm JJ 4

SIMULATION RESULTS


Experimental System Setup

Fig. 9. Pentium-800–based PMSM incremental motion control system.


Fig. 10. (a) Experimental results controlled by multisegment SMC

controller. From top to bottom: velocity responses, position responses, control output, and phase-A current.


Fig. 10. (b) Experimental trajectories of four segments controlled by multisegment SMC controller.


Fig. 11. Experimental results controlled by conventional SMC controller. From top to bottom: velocity responses, position responses, control output, and phase-A current.


Fig. 12. Experimental results with generator load. From top to bottom: velocity responses, position responses, and phase-A current.


CONCLUSION

A particular incremental motion control using novel VSC strategy for a PMSM is presented. It has been shown that the multisegment SMC has the ability to control the motor system with a constant acceleration and deceleration rate to match the trapezoidal velocity profile of the incremental motion.

Furthermore, the proposed system is robust to the external time-varying load.

Both simulations and experimental results confirm the validity.


REFERENCES

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REFERENCES

[6] K.-C. Hsu, “Variable structure control design for uncertain dynamic systems

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1998.

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[8] J. Y. Hung, W. Gao, and J. C. Hung, “Variable structure control: A

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[9] F. J. Lin, “Real-time IP position controller design with torque feedforward

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no. 3,pp. 398–407, Jun. 1997.

[10] F. J. Lin and S. L. Chiu, “Robust PM synchronous motor servo drive with

variable-structure model-output-following control,” Proc. IEE—Elect.

Power Appl., vol. 144, no. 5, pp. 317–324, 1997.


REFERENCES

[11] M. Ghribi and H. Le-Huy, “Optimal control and variable structure

combination using a permanent-magnet synchronous motor,” in Conf.

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controller for position control of synchronous reluctance motor,” IEEE

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