What is step motor drive breakdown
As you can see in figure 3, the phase current of the step motor is distributed by the sinusoidal function (as shown in the dotted line). The larger the fraction, the closer the current is to the sine curve. Step 2: the relationship between the step motor and the motor stability is measured in the step distance of the motor, which is 1.8 degrees. At the time of the experiment, the motor speed was set to 2 r/s. When the motor 2 is subdivided, the motor is 400 steps per turn, and the cycle is 1.25 ms. When the machine is subdivided, the motor has a period of 0.3125 ms per step. When the motor 64 is subdivided, the motor has 12800 steps per cycle, 0.0391 ms per step period. When the step is subdivided, the current waveform step is uniform, and the current pulse is high, the maximum is 70.7% of the maximum current. When stepping into the 8 subdivision of the motor, the current waveform step is obvious, but the current ripple value is small, the maximum is 19.5% of the maximum current; Stepping motor subdivision, 64 current waveform is smooth, the current waveform has been difficult to distinguish, respectively, the number of steps, maximum current pulse is only 2.45% of the maximum current. By electromagnetic induction theorem, stepper motor output torque and motor coil current is proportional to the, and: T = KT * I type in the KT as the motor torque constant, it with the motor structure, the material, the length of the coil and other factors.
The basic concepts of segmentation: The stepping motor is driven by the breakdown drive and the Angle of the step is smaller. Such as the drive to work in the state of 10 subdivision, the step from the Angle of only one over ten of the "fixed interval Angle", namely: when a drive to work in step don't segment of the whole state, each hair a step pulse control system, motor rotation 1.8; With a breakdown drive, the motor is only 0.18 degrees when it is subdivided. The breakdown function is completely driven by the electrical current of the actuator by the actuator, which is independent of the motor. Figure 2 shows the schematic diagram of the two-phase step motor, which has two winding A and B. When a winding is energized, its stator magnetic pole generates a magnetic field, which absorbs the rotor to the pole
The formula is easy to understand: the higher the motor, the smoother the motor. The smaller the step motor, the larger the vibration when the motor is running. Because of the high fine score, the current curve is smooth, so the output torque of the motor is small, the motor runs smoothly. Motor fine fraction is small, current ripple is big, the output torque ripple is big, thus cause the vibration of the motor is bigger, the vibration and noise and other parts of the resonance noise. 3. Conclusion stepping motor subdivision drive circuit not only can improve the running smoothness of work platform, and can effectively improve the positioning precision of the work platform. The test shows that the motor can be accurately positioned at every step in the synchronous belt motor. Recommended in motion controller of the output pulse frequency permits, as far as possible the fine fraction of the stepper motor drives a bigger, to improve the running smoothness of motion platform; But the positioning precision of the sports platform can only be calculated by the pulse equivalent of the step forward motor 4.
To understand the segmentation, it is important to understand the concept of a step Angle: it means that the control system each sends a pulse signal, which is the Angle of rotation. Motor factory is given a step away from the Angle of value, such as FY86EL402A type motor is given a value of 0.9 ° / 1.8 ° (half step work step 0.9 °, the whole work of 1.8 °), the interval Angle may call it the 'inherent interval Angle motor, it is not necessarily the real step away from the Angle of motor when the actual work. In short, a fine score is the actual step Angle at the run time of an electric motor. As can be seen from the table above, stepping motor drive to work in the state of 10 subdivision, the interval Angle for 'step motor inherent from the Angle of one over ten, that is to say: when a drive to work in step don't segment of the whole state, each hair a step pulse control system, 1.8 ° motor rotation; With subdivision driver work breakdown in 10 state, motor rotation only 0.18 °, which is the basic concept of subdivision. The more accurate description of the driver subdivision feature is the number of pulses that are run, and the number of pulses that are required to move each time a step into the motor run. FY86EL402A motor has 50 teeth, and if the run number is set to 160, then the step forward motor will need 50 times 160 = 8000 steps. Corresponding interval Angle is 360 ° present 8000 = 0.045 °. Note that if the running number is set to 30, the above table corresponds to a fine score of 7.5, not an integer.
