3
3.2 Tiêu chu1n Nyquist theo c tính tn s logarit .....................................................37
3.3 Tiêu chu1n n nh Mikhailov...............................................................................38
4 Phng pháp qu2 o nghim s ..................................................................................38
4.1 Phng pháp xây dng QNS ..............................................................................38
Chng 4: CH3T L4NG C*A QUÁ TRÌNH I"U KHI#N
1 Khái nim chung...........................................................................................................41
1.1 Ch xác l-p ......................................................................................................41
1.2 Quá trình quá ...................................................................................................41
2 ánh giá ch5t l6ng ch xác l-p............................................................................41
2.1 Khi u(t) = U
0
.1(t) ..................................................................................................42
2.2 Khi u(t) = U
0
.t.......................................................................................................42
3 ánh giá ch5t l6ng quá trình quá .........................................................................42
3.1 Phân tích thành các biu th+c n gin..................................................................42
3.2 Phng pháp s Tustin..........................................................................................42
3.3 Gii phng trình trng thái ..................................................................................44
3.4 S7 d'ng các hàm ca MATAB..............................................................................44
4 ánh giá thông qua d tr n nh...........................................................................45
4.1 d tr biên ..................................................................................................45
4.2 d tr v pha ...................................................................................................45
4.3 Mi liên h gia các d tr và ch5t l6ng iu khin........................................45
5 Tính iu khin 6c và quan sát 6c ca h thng ....................................................46
5.1 iu khin 6c....................................................................................................46
5.2 Tính quan sát 6c................................................................................................46
Chng 5: NÂNG CAO CH3T L4NG VÀ T/NG H4P H TH!NG
1 Khái nim chung...........................................................................................................48
2 Các b iu khin – Hiu ch,nh h thng......................................................................48
2.1 Khái nim .............................................................................................................48
2.2 B iu khin t, l P..............................................................................................48
2.3 B bù s8m pha Lead .............................................................................................48
2.4 B bù tr. pha Leg..................................................................................................49
2.5 B bù tr.-s8m pha Leg -Lead................................................................................50
2.6 B iu khin PI (Proportional Integral Controller)...............................................51
2.7 B iu khin PD (Proportional Derivative Controller) .........................................51
2.8 B iu khin PID (Proportional Integral Derivative Controller)...........................52
3 Tng h6p h thng theo các tiêu chu1n ti u ...............................................................53
3.1 Phng pháp ti u modun ...................................................................................53
3.2 Phng pháp ti u i x+ng ................................................................................54
Chng 6: H TH!NG I"UKHI#N GIÁN ON
1 Khái nim chung...........................................................................................................56
2 Phép bin i Z.............................................................................................................56
2.1 nh ngh&a ............................................................................................................56
2.2 Mt s tính ch5t ca bin i Z .............................................................................57
2.3 Bin i Z ng6c ..................................................................................................57
3 L5y m9u và gi m9u .....................................................................................................58
3.1 Khái nim .............................................................................................................58
3.2 L5y m9u................................................................................................................58
3.3 Gi m9u................................................................................................................59
4 Hàm truyn t h gián on.........................................................................................60
4.1 Xác nh hàm truyn t W(z) t( hàm truyn t h liên t'c .................................60
4.2 Xác nh hàm truyn t t( phng trình sai phân.................................................65
5 Tính n nh ca h gián on ......................................................................................65
5.1 Mi liên h gia mt ph:ng p và mt ph:ng z........................................................65
5.2 Phép bin i tng ng ...................................................................................65
Ph' l'c: CONTROL SYSTEM TOOLBOX & SIMULINK TRONG MATLAB