【導讀】步進電機是最常見的一種電機，作為一種數字伺服執(zhí)行元件，能與控制芯片相結合成伺服控制系統(tǒng)；具有良好的隨動性，能夠實現精準控制，在現代控制領域中具有不可替代的作用。步進電機控制系統(tǒng)主要由步進控制器，功率放大器及步進電機等組成。采用單片機控制，用軟件代替上述步進控制器，使得線路簡單，成本低，可靠性大大增加。軟件編程可靈活產生不同類型步進電機勵磁序列來控制各種步進電機的運行方式。本設計主要思想是以AT89C52單片機為控制核心，L297和L298N作為驅動芯片。通過單片機內部的定時器改變CP脈沖的頻率時間對步進電機的轉速控制，實現電機調速與正反轉功能，并將電機所處的狀態(tài)用數碼管顯示出來。步進電機是將電脈沖信號轉變?yōu)榻俏灰苹蚓€位移的開環(huán)控制元件。這一線性關系的存在，加上步進電機

　　

【正文】 f pulses to control the amount of angular displacement, so as to achieve the purpose of accurate positioning。 At the same time, you can by controlling the pulse frequency to control the motor rotation speed and acceleration,so as to achieve the purpose of speed. Stepper motor directly from the ACDC power supply, and must use special equipment stepper motor drive. Stepper motor drive system performance, in addition to their own performance with the motor on the outside, but also to a large extent depend on the drive is good or bad. A typical stepper motor drive system is operated by the stepper motor controller, stepper motor drives and stepper motor body is posed of three parts. Stepper motor controller stepper pulse and direction signal, each made of a pulse, stepper motordriven stepper motordrives a rotor rotating step angle, that is, stepbystep further. High or low speed stepper motor, or speed, or deceleration, start or stop pulses are entirely dependent on whether the level or frequency. Decide the direction of the signal controller stepper motor clockwise or counterclockwise rotation. Typically, the stepper motor drive circuit from the logic control, power driver circuit, protection circuit and power ponents. Stepper motor drive controller, once received from the direction of the signal and step pulse, the control circuit on a predetermined way of the electrical powerphase stepper motor excitation windings of the conduction or cutoff signal. Control circuit output signal power is low, can not provide the necessary stepping motor output power, the need for power amplifier, which is stepper motor driven power drive part. Power stepper motor drive circuit to control the input current winding to form a space for rotating magnetic field excitation, the rotordriven movement. Protection circuit in the event of short circuit, overload, overheating, such as failure to stop the rapid drive and motor. Motor is usually for the permanent magnet rotor, when the currentflows through the stator windings, the stator windings produce a magnetic field vector. The magnetic field will lead to a rotor angle of rotation, making a pair of rotor and stator magnetic field direction of the magnetic field direction. When the stator rotating magnetic field vector from a different angle. Also as the rotor magnetic field toa point of view. An electrical pulse for each input, the motor rotation angle step. Its output and input of the angular displacement is proportional to the pulses, with pulse frequency proportional to to change the order of winding, the electrical will be can, therefore, control the pulse number, frequency and electricalpower windings of each phase to control the order of rotation of stepper motor. Stepper motor types:Permanent magnet (PM). Magnetic generally twophase stepper, torque and are smaller and generally stepping angle of degrees or 15 degrees。 put more wind for airconditioning. Reactive (VR), the domestic general called BF, have a mon threephase reaction, step angle of degrees。 also have fivephase reaction. Noise, no torque has been set at a large number of out.Hybrid (HB), mon twophase hybrid, fivephase hybrid, threephase hybrid, fourphase hybrid, twophase can be mon with the fourphase drive, fivephase threephase must be used with their drives。 Twophase, fourphase hybrid step angle is degrees more than a small size, great distance, and low noise。Fivephase hybrid stepping motor is generally , the motor step angle small, high resolution, but the plexity of drive circuits,wiring problems, such as the 5phase system of 10 lines. Threephase hybrid stepping motor step angle of degrees, butaccording to the use of degrees, the threephase hybrid stepping motor has a twophase mixed than the fivephase hybrid more pole willhelp electric folder symmetric angle, it can be more than twophase, fivephase high accuracy, the error even smaller, run more smoothly. Stepper motor to maintain torque: stepper motor power means no rotation, the stator locked rotor torque. It is a stepper motor, one ofthe most important parameters, usually in the lowspeed stepper motortorque at the time of close to maintain the torque. As the stepper motor output torque increases with the speed of constant attenuation, the output power also increases with the speed of change, so as to maintain torque on the stepper motor to measure the parameters of one ofthe most important. For example, when people say that the stepper motor , in the absence of special circumstances that means for maintaining the torque of the stepper motor . Precision stepper motors: stepper motor step angle accuracy of 35%, not cumulative. Start frequency of noload: the stepper motor in case of noload to the normal start of the pulse frequency, if the pulse frequency ishigher than the value of motor does not start, possible to lose stepsor blocking. In the case of the load, start frequency should be lower. If you want to achieve highspeed rotation motor, pulse frequency should be to accelerate the process, that is, the lower frequency to start, and then rose to a certain acceleration of the desired frequency (motor speed from low rise to highspeed). Step angle: that is to send a pulse, the electrical angle corresponding to rotation. Torque positioning: positioning torque stepper motor does not refer to the case of electricity, locked rotor torque stator. Operating frequency: stepbystep stepper motor can run without losing the highest frequency. Subdivision Drive: stepper motor drives the main aim is to weakenor eliminate lowfrequency vibration of the stepper motor to improve the accuracy of the motor running. Reduce noise. If the step angle 176。 (full step) the twophase hybrid stepping motor, if the breakdown of the breakdown of the number of drives for the 8, then the operation of the electrical pulse for each resolution of 176。, the precision of motor can reach or close to 176