第10章习题解答
10-1 伺服系统的结构如图所示,
*?m?500s(0.1s?1)?m
*计算三种输入下的系统给定误差:(1)?m?*?m?(1?t?t2)?1(t)。
1t*(2)?m(3)?1(t);??1(t);
2212解:系统开环传递函数W(s)?500s(0.1s?1)
*s?m(s)esr(?)?limesr(t)?limsEsr(s)?limt??s?0s?01?W(s)系统给定误差
**s?m(s)s2?m(s)(0.1s?1)
?lim?lims?0s?0s(0.1s?1)?5005001?s(0.1s?1)*(1)?m?11* (s)??1(t),?m22s*s2?m(s)(0.1s?1)s(0.1s?1)?lim?0 系统给定误差esr(?)?lims?0s(0.1s?1)?500s?02s(0.1s?1)?500*(2)?m?1t*(s)?2 ?1(t),?m22s*s2?m(s)(0.1s?1)0.1s?11?lim?系统给定误差esr(?)?lim
s?0s(0.1s?1)?500s?02[s(0.1s?1)?500]1000111s2?s?112*?2?3?(3)??(1?t?t)?1(t),?m(s)? 3ssss2*ms2?s?1(0.1s?1)*s2?m(s)(0.1s?1)s?lim?? 系统给定误差esr(?)?lims?0s(0.1s?1)?500s?0s(0.1s?1)?500
10-2 直流伺服系统控制对象如图10-8所示,机械传动机构的传动比j?10,驱动装置的放大系数Ks?40及滞后时间常数Ts?0.001s,直流伺服电机等效参数Tm?0.086s,
Tl?0.012s,Ce?0.204,位置调节器APR选用PD调节器,构成单环位置伺服系统,求
出调节器参数的稳定范围。
解:驱动装置传递函数W1(s)?Ks40?
Tss?10.001s?1W2(s)?直流伺服电机传递函数
1/Ce4.9?TmTls2?Tms?10.001s2?0.086s?14.9(0.0139s?1)(0.0721s?1)110.1?? js10ss
?机械传动机构传递函数W3(s)?*udKsTss?1Ud01/CeTmTls2?Tms?1?1js?m
直流伺服系统控制对象传递函数为
Wobj(s)?Ks/(jCe)s(Tss?1)(TmTls2?Tms?1)19.6?s(0.001s?1)(0.0139s?1)(0.0721s?1)
PD调节器传递函数WAPR(s)?WPD(s)?Kp(1??ds),?d?0.0721 伺服系统开环传递函数
19.6KpK?(?ds?1) W?op(s)??s(Tss?1)(TmTls2?Tms?1)s(0.001s?1)(0.0139s?1)为保证系统稳定,须使Kp?0.001?0.0139?54.7。
19.6?0.001?0.0139
10-3 对题10-2中的直流永磁伺服电机采用电流闭环控制,电流闭环等效传递函数
112?,系统的转动惯量J?0.011kg?m,设计位置调节器,要求系统对负载Tis?10.07s?1扰动无静差,求出调节器参数的稳定范围。
解:带有电流闭环控制的对象结构图
TL*Id1Tis?1IdCTTe??1Js?1js?m
忽略负载转矩TL时,带有电流闭环控制对象的传递函数为
Wobj(s)?CT/(jJ)9.55?0.204?0.117.71??
s2(Tis?1)0.011s2(0.07s?1)s2(0.07s?1)(?is?1)(?ds?1)
?is选用PID调节器,其传递函数为WAPR(s)?WPID(s)?Kp伺服系统的开环传递函数为
Kp(?is?1)(?ds?1)CT/(jJ)17.71Kp(?is?1)(?ds?1) W?op(s)???iss2(Tis?1)?is3(0.07s?1)设????d,由Routh稳定判据求得系统稳定的条件
??i??d?2Ti? 1?K???2?2(??2T)iii?令?i??d?2.2Ti?0.154,则
Kp?110.064???13.095
2?i(?i?2Ti)17.71?0.88Ti20.072
10-4 对题10-3中的带有电流闭环控制的对象设计转速闭环控制系统,转速闭环等效传递函数Wncl(s)?KN(?ns?1),其中,h?5,T?n?0.015s?n?hT?n?0.75s,
T?ns3?s2?KN?ns?KNKN?h?1*?300?,设计位置调节器,当输入为阶跃信号时,伺服系统稳态无静差,m222hT?n求出调节器参数的稳定范围。求出调节器参数的稳定范围。 解:控制对象的传递函数