精品課件大學(xué)物理2(雙語)(編輯修改稿)
2025-06-01 15:54 本頁面
【文章內(nèi)容簡介】 代數(shù)運算規(guī)則 例 ? ? )()23()()2)(1( 2 tfpptfpp ?????)()()()()()()()(tftytpftpyctftytfdtdtydtd?????不等于即 兩端積分得 )(1)(1 tfpptfpp ?????Example： Page 40 。 Example: y39。39。(t)+6y39。 (t)+8y(t) = f(t), t ? 0 y(0)=1, y39。(0)=2, f(t) = sin t u(t) y39。39。 (t)+6y39。 (t)+8y(t) = 0的通解 yh(t) (unforced solution固有響應(yīng) ) yh(t) = Ae?2t+Be?4t y39。39。 (t)+6y39。 (t)+8y(t) = f(t)一個特解 yp(t) (forced solution強制響應(yīng) ) yp(t)=(1/11)sint+(?2/33)cost c. Now we need to find a particular solution to the differential equation 0,c o s33211s i n66126653)( 42 ????? ?? ttteety ttzeroinput solution零輸入響應(yīng) linear differential equations solution )()()( tytyty ph ??由上例的求解過程，可看出經(jīng)典法有如下的不足之處： (1)若微分方程右邊激勵項較復(fù)雜，則難以處理。 (2)若激勵信號發(fā)生變化，則須全部重求解。 (3)若初始條件發(fā)生變化，則須全部重求解。 zeroinput solution零輸入響應(yīng) linear differential equations solution Physical solution 1. zeroinput solution )()()()( tfpNtypD ??????nitixxiectytfty1)(0)()(?出特征根 根據(jù)特征方程求由初始條件 nn cccyyy ，求出， ?? ???? ,21139。 ,),0(),0(),0(zeroinput solution零輸入響應(yīng) linear differential equations solution 2. zerostate solution 注：兩種解法的區(qū)別，初始條件代入的先后次序不同 3. total solution Homogeneous solution (zeroinput solution) n階齊次方程的解（零輸入響應(yīng)的求解） 0)()(0)()( 0111 ???????? ?? tyapapaptypD xnnn1. The roots of the characteristic polynomial 求特征方程的根 2. Homogeneous solution 根據(jù)特征根得值，寫出零輸入響應(yīng) ????????nititnttxiin ecececectyt h e nr o o t sd i s t i c tna r eIf1212121)( , ??????? ，①The roots of the characteristic polynomial are called natural frequencies. These are frequencies for which there is an output in the absence of an input. )(, 21 tyccc xn 代入，得零輸入響應(yīng)將 ?例： 47頁 ， 50頁 tjtjx ecectyjr o o t sc o m p l e x)(2)(12,1)( ????????? ?????、?????? ??????nijtjritirixrjecetctyr o o t stn o n d i s t i n c11211)( ?????②The unit impulse response and zerostate response of system Unit impulse response The unit impulse response gives intuition about the properties of a system. The impulse response is the response of a system to unit impulse signal. 系統(tǒng))( t? )( th零狀態(tài)Relationship of H(p) amp。 h(t) )()()()( tfpktfpHty????)()()( tkftydt tdy ?? ?)()()( tfketyedttdye tttem u l t i p l y t ??? ?? ??? ?????? ?? ?tt etkftyedd ????? ?? )()]([? ?? ?? ??? ?? tto dfekye 0i n t e g r a l )()( ??? ????? ? ??? t tf dfekty 0 )( )()( ????? ? ?? ??? t tt dfekeyty 0 )( )()0()( ?????Unit impulse response When ， the response is the unit impulse response of system. )()( ttf ??)()()()(00)(tkedekedekthtttt t???????????????? ?????? ?、?零輸入響
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號-1