【正文】 . 摘 要 隨著時(shí)代的進(jìn)步和科技的發(fā)展，電機(jī)調(diào)速系統(tǒng)在工農(nóng)業(yè)生產(chǎn)、交通運(yùn)輸以及日常生活中起著越來(lái)越重要的作用 。直流電機(jī)是通過(guò)兩個(gè)磁場(chǎng)的相互作用而發(fā)生旋轉(zhuǎn)的。定子通過(guò)永磁體或受激勵(lì)電磁鐵產(chǎn)生一個(gè)固定磁場(chǎng)，轉(zhuǎn)子由一系列繞組和導(dǎo)磁材料構(gòu)成，電流通過(guò)每個(gè)繞組時(shí)都會(huì)產(chǎn)生磁場(chǎng)。對(duì)有刷直流電機(jī)而言，轉(zhuǎn)子上的換向器和定子上的電刷在電機(jī)旋轉(zhuǎn)時(shí)為每個(gè)繞組供給電能。通電轉(zhuǎn)子繞組與定子磁體有相反的極性，通過(guò)相互吸引而產(chǎn)生轉(zhuǎn)矩使轉(zhuǎn)子轉(zhuǎn)動(dòng)。電機(jī)的速度與施加的電壓成正比，轉(zhuǎn)矩則與電流成正比。對(duì)直流電機(jī)的控制是一個(gè)挑戰(zhàn)，因?yàn)楸仨氃诠ぷ髌陂g改 變直流電機(jī)的速度。使直流電機(jī)高效運(yùn)行最常用的的方法是施加一個(gè) PWM（脈寬調(diào)制）方波，其通斷比率對(duì)應(yīng)于所需的速度。電機(jī)起到一個(gè)低通濾波器的作用，它將 PWM 的信號(hào)轉(zhuǎn)換為有效直流電平。 本 次實(shí)訓(xùn) 采用 STC89C52 單片機(jī)與 L298N 驅(qū)動(dòng)芯片驅(qū)動(dòng) 直流 電機(jī)工作 ，單片機(jī)控制的直流脈沖（ PWM）調(diào)速及旋轉(zhuǎn)方向控制系統(tǒng)，并且詳細(xì)論述了該系統(tǒng)的控制方法、結(jié)構(gòu)、參數(shù)設(shè)計(jì)、程序設(shè)計(jì)等方面的問(wèn)題。該系統(tǒng)結(jié)構(gòu)簡(jiǎn)單，調(diào)速性能好，性能價(jià)格比高，真正實(shí)現(xiàn)了直流電機(jī)調(diào)速系統(tǒng)及旋轉(zhuǎn)方向的控制。 關(guān)鍵詞： 直流電機(jī) ； STC89C52 單片機(jī) ； L298N 驅(qū)動(dòng)電路 . Abstract With the progress of the times and the development of science and technology, motor speed control system in the industrial and agricultural production, transportation and daily life plays an increasingly important role in. DC motor is acplished by a two magic field interactions which occur rotation. The stator by permanent mags or stimulated the electromag produces a fixed magic field, the rotor is posed of a series of winding and the magic materials formed, the current through each winding will generate a magic field. The brush DC motor, rotor and stator of the mutator brush in the motor rotates for each winding supplies electrical energy. Energized rotor winding and the stator mags have opposite polarity, through attraction to produce torque rotating the rotor. The speed of the motor and the applied voltage is proportional to the torque is proportional to the current, and the. For the DC motor control is a challenge, because must be at work during changing the speed of DC motor. The DC motor is the efficient operation of most monly used method is applied to a PWM ( pulse width modulation ) square wave, the onoff ratio corresponding to the desired speed. The motor has a low pass filter function, it will PWM signal is converted to an effective level. The design of STC89C52 monolithic integrated circuits to control the PID the direct pulse （ PWM ） machinery velocity modulation system, and elaborated on the system of control methods, structure and design, the application design problems. the system simple and good performance machinery velocity modulation prices are high, really to direct the electrical machinery velocity modulation control system of highprecision. Key words： monolithic integrated circuits, a direct motor, machinery velocity modulation system . 引言 ................................................................................................................................. 4 1 系統(tǒng)硬件介紹 .............................................................................................................. 4 硬件主控芯片概述及功能介紹 ................................................................... 4 STC89C52 單片機(jī)主控制電路圖 .................................................................. 4 L298N 直流電機(jī)的專(zhuān)用驅(qū)動(dòng)器 .................................................................. 6 硬件電路設(shè)計(jì) .................................................................................................. 7 顯示電路的設(shè)計(jì) ......................................................................................... 7 鍵盤(pán)電路的設(shè)計(jì) ......................................................................................... 8 電機(jī)驅(qū)動(dòng)電路 的設(shè)計(jì) ................................................................................... 8 2 系統(tǒng)軟件設(shè)計(jì) .............................................................................................................. 9 設(shè)計(jì)要求 ............................................................................................................. 9 總體設(shè)計(jì)方案 ...................................................................................................... 9 設(shè)計(jì)思路 ................................................................................................... 9 方案論證與設(shè)計(jì) ....................................................................................... 9 系統(tǒng)組成 ................................................................................................ 10 3 硬件制作、調(diào)試與軟件 .............................................................................................. 10 系統(tǒng) PCB板的設(shè)計(jì) ........................................................................................... 10 系統(tǒng)硬件調(diào)試 .................................................................................................... 11 主控程序 ........................................................................................................... 11 4 實(shí)訓(xùn)心得體會(huì) ............................................................................................................ 13 謝 辭 ............................................................................................................................ 14 參考文獻(xiàn) ........................................................................................................................ 15 附錄 A： ........................................................................................................................ 17 附錄 B： ........................................................................................................................ 18 附錄 C： ............................................................