Motor drive control is to control the motor rotation or stop, and the speed of rotation.The motor drive control part is also called electronic speed controller (ESC).Electrical adjustment corresponding to the use of different motors, including brushless and brush electrical adjustment.
The permanent magnet of the brush-motor is fixed, the coil is wound around the rotor, and the direction of the magnetic field is changed by a discontinuous contact between the brush and the commutator to keep the rotor rotating continuously.
Brushless motor, as its name suggests, does not have the so-called brush and commutator. Its rotor is a permanent magnet, while the coil is fixed. It is directly connected to the external power supply.
In fact, the brushless motor also needs an electronic governor, which is basically a motor drive. It changes the direction of the current inside the fixed coil at any time, so as to ensure that the force between it and the permanent magnet is mutually repulsive and the continuous rotation can be continued.
Brushless motor can work without the need for electrical adjustment, direct supply of electricity to the motor can work, but this can not control the motor speed.Brushless motor must have electric adjustment, or it cannot rotate.Direct current must be converted to three - phase alternating current by brushless current regulation.
The earliest electrical adjustment is not like the current electrical adjustment, the earliest is a brush electrical adjustment, said this you may want to ask, what is a brush electrical adjustment, and now the brushless electrical adjustment has what difference.
In fact, there is a big difference between the brushless and the brushless are based on the motor. Now the rotor of the motor, which is the part that can rotate, is all the magnet block, and the coil is the stator that does not rotate, because there is no carbon brush in the middle, this is the brushless motor.
And a brush motor, as the name suggests is a carbon brush, so there is a brush motor, like we usually children play with the remote control of the motor is a brush motor.
According to the two types of electrical machinery and the name of the brush and brush - free electric regulation.From a professional point of view it is a brush is the output of direct current, brushless power output is three-phase ac.
Direct current is the electricity stored in our battery, which can be divided into positive and negative poles. The power supply of our household 220V, used for mobile phone charger or computer, is ac.Ac is with a certain frequency, generally speaking is a line of plus and minus, plus and minus back and forth exchange;A direct current is a positive pole and a negative pole.
Now that ac and dc are clear, what is three-phase electricity?According to the theory, three-phase alternating current is a transmission form of electricity, referred to as three-phase electricity, which is composed of three alternating potential with the same frequency, the same amplitude and the phase difference of 120 degrees successively.
Generally speaking, it is our household three alternating current, in addition to voltage, frequency, drive Angle is different, other are the same, now for three-phase electricity and direct current are understood.
Brushless, the input is direct current, through a filter capacitor to stabilize the voltage.Both of then divided into two road, all the way is electrically controlled BEC use, BEC is for receiver and electrically controlled MCU used in power supply, the output to the receiver of the power cord is the red lines on the line and black line, the other is involved in MOS tube to use all the way, here, the electrically controlled with electricity, SCM started, drive MOS pipe vibration, make motor drops dripping sound.
Some electric adjustments are equipped with throttle calibration function. Before entering the standby system, it will monitor whether the throttle position is high or low or in the middle. If the throttle position is high, it will enter into the calibration of electric adjustment journey.
When everything is ready, the single-chip microcomputer in the electrical adjustment will decide the output voltage and frequency as well as the driving direction and input Angle to drive the motor speed and turn according to the signal on the PWM signal line.This is the brushless electromodulation principle.
When the drive motor is running, a total of three groups of MOS tube work within electrical modulation, two in each group, the positive output a control, a control negative output, when the positive output, negative output, not negative, the output of the output is highly, it has formed an alternating current, also, to do this work, three groups of their frequency is 8000 hz.Speaking of this, brushless electrical regulation is also equivalent to a factory motor used on the frequency converter or governor.
The input is dc, usually powered by lithium batteries.The output is three-phase ac, which can drive the motor directly.
In addition, the airmodel brushless electronic governor also has three signal input lines, input PWM signal, used to control the motor speed.For aeromodels, especially for four-axis aeromodels, special aeromodels are needed because of their particularity.
So why do you need special electrical tuning on the quad, what's so special about it?
The quad has four OARS, and the two OARS are relatively crisscross.The forward rotation and reverse rotation on the paddle's steering can offset the spin problems caused by the rotation of a single blade.
The diameter of each oar is small, and the centrifugal force is dispersed as the four OARS rotate.Unlike a straight paddle, there is only one inertial centrifugal force that generates a concentrated centrifugal force that forms a gyroscopic property, keeping the fuselage from turning over quickly.
Therefore, the frequency of update of steering gear control signal is very low.
Four axis in order to quick response, in response to postural changes caused by drift, need high speed electric adjustable, the renewal speed of conventional PPM electrically controlled only about 50 hz, doesn't satisfy the need that control the speed, and PPM electric control MCU built-in PID, can the speed change characteristics of conventional model aircraft to provide smooth, on four axis is not appropriate, four axis motor speed changes in need is a quick reaction.
With high speed special electrical adjustment, IIC bus interface transmission control signal, can achieve hundreds of thousands of motor speed changes per second, in the four-axis flight, attitude moment can be maintained stable.Even by the sudden impact of external forces, still intact.
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Post time: Aug-29-2019
