I. Introduction
Stepper motor is an open-loop control element that transforms an electrical pulse signal into an angular displacement or line displacement. In the case of non-overload, the speed of the motor, the position of the stop depends only on the frequency of the pulse signal and the number of pulses, and is not affected by the load change, that is, add a pulse signal to the motor, the motor is turned over a step angle. The existence of this linear relationship, coupled with the stepper motor only periodic error without cumulative error and other characteristics. Make in the speed, position and other control areas with stepper motor to control become very simple.
While the stepper motor has been widely used, but the stepper motor can not be as ordinary DC motor, AC motor in the regular use. It must be a double ring pulse signal, power drive circuit control system can be used. Therefore, with a good stepper motor is not easy, it involves machinery, motor, electronics and computers and many other specialized knowledge.
At present, the production of stepper motor manufacturers are indeed many, but with professional and technical personnel, to develop their own, research and development of manufacturers is very little, most of the manufacturers are only one, twenty people, even the most basic equipment are not. Only in a blind imitation stage. This will give the user in the product selection, the use of many problems. Signed in the above situation, we decided to take a wide range of induction sub-stepping motor as an example. Describe its basic working principle. Hope to help the majority of users in the selection, use, and machine improvement.
Second, the inductor stepper motor principle
(a) reactive stepper motor principle
As the reactive stepper motor working principle is relatively simple. The following first describes the principle of three-phase reactive stepper motor.
1, structure:
Motor rotor evenly distributed with many small teeth, stator teeth have three excitation winding resistance, its geometric axis in turn, respectively, with the rotor tooth axis staggered. 0, 1/3 て, 2/3 て, (the distance between the axes of the two neighboring rotor teeth for the distance between the teeth to て that is, A and the teeth of the 1 relative flush, B and the teeth of the 2 staggered to the right of the 1/3 て, C and the teeth of the 3 staggered to the right of 2/3 て, A' and the teeth of the 1 staggered to the right of the 2/3 て, A' and the teeth of the 5 staggered to the right, 2/3 て. If phase B is energized, A, C phase is not energized, tooth 2 should be aligned with B, at this time the rotor moved to the right over 1/3 て, at this time, tooth 3 and C offset 1/3 て, tooth 4 and A offset (て-1/3 て) = 2/3 て. If phase C is energized, phase A, B is not energized, tooth 3 should be aligned with C. At this time, the rotor is shifted to the right by 1/3て, and at this time, tooth 4 is aligned with A offset by 1/3て. If the A phase is energized, B, C phase is not energized, teeth 4 and A alignment, the rotor and moved to the right over 1/3 て so that after A, B, C, A respectively energized state, teeth 4 (that is, the teeth 1 before the first tooth) moved to the A phase, the motor rotor rotated to the right over a tooth distance, if you constantly press A, B, C, A ...... energized, the motor is every step (per pulse) 1/3て,rotates to the right. If you press A,C,B,A...... energized, the motor reverses.
This shows that: the position and speed of the motor by the number of conductive (number of pulses) and frequency into a one-to-one relationship. And the direction is determined by the order of conductivity.
However, for torque, smoothness, noise, and angle reduction considerations. Often use A-AB-B-BC-C-CA-A this conductive state, so that the original 1/3 て per step changed to 1/6 て. Even through the two-phase current different combinations, so that its 1/3 て changed to 1/12 て, 1/24 て, which is the basic theoretical basis of the motor subdivision drive.
It is not difficult to introduce: the motor stator has m-phase excitation winding resistance, whose axes are offset from the rotor tooth axis 1/m,2/m ......(m-1)/m,1 respectively. and conducts electricity according to a certain phase sequence motor can be forward and reverse rotation is controlled - this is the Stepper motor rotation of the physical conditions. As long as this condition is met we can theoretically manufacture any phase of the stepper motor, for cost and other considerations, the market is generally two, three, four, five-phase for more.
3, torque:
Once the motor is energized, the stator and rotor will produce a magnetic field (flux Ф) when the rotor and stator staggered at a certain angle to produce a force F and (d Ф/d θ) proportional to the S its flux Ф=Br * S Br for the magnetic density, S for the magnetically conductive area F and L * D * Br proportional to the L for the effective length of the iron core, D for the diameter of the rotor Br = N?I / R N? I for the excitation winding an number of turns (current multiplied by the number of turns) R is the magnetoresistance.
Torque=Force*Radius
Torque is proportional to the effective volume of the motor*Number of ampere-turns*Magnetic Density (only linear state is taken into account) Therefore, the larger the effective volume of the motor, the larger the number of excitation ampere-turns, and the smaller the air-gap between the stator and rotor, the larger the torque of the motor, and vice-versa.
(B) Induction stepping motor
1, features:
Induction stepping motor and the traditional reaction stepping motor, compared with the structure of the rotor with permanent magnets to provide a soft magnetic material work point, and the stator excitation only need to provide a changing magnetic field and do not have to provide the magnetic material work point of the energy dissipation, so that the motor is highly efficient, small current, low heat. Due to the existence of permanent magnets, the motor has a strong counterpotential, and its own damping effect is better, so that it is smoother, lower noise, low-frequency vibration is small in the process of operation.
The inductor stepping motor can be regarded as a low-speed synchronous motor to some extent. A four-phase motor can operate as four-phase or two-phase. (It must be driven by bipolar voltage.) This is not the case with reactive motors. For example, a four-phase, eight-phase operation (A-AB-B-BC-C-C-D-CD-D-DA-A) can be completely two-phase, eight-beat operation. It is not difficult to find the conditions for C=,D=.
A two-phase motor internal winding and four-phase motor is identical, small power motors are generally connected directly to the two-phase, while the power of the motor, in order to facilitate the use of the motor, the flexibility to change the dynamic characteristics of the motor, often its external wiring for the eight leads (four-phase), so that when used, both as a four-phase motor can be used for the use of motor windings for two-phase motor can be connected in series or parallel use.
2, classification
Induction sub-stepping motor to the number of phases can be divided into: two-phase motor, three-phase motor, four-phase motor, five-phase motor. To the seat number (motor outside diameter) can be divided into: 42BYG (BYG for induction sub-stepping motor code), 57BYG, 86BYG, 110BYG, (international standards), and like 70BYG, 90BYG, 130BYG, etc. are all domestic
Two, three, the drive control system components
Using, controlling stepping motors must be composed of the ring pulse, the power amplification and other components of the control system. Power amplification and other components of the control system, the block diagram is as follows:
1, pulse signal generation.
Pulse signals are generally generated by the microcontroller or CPU, the general duty cycle of the pulse signal is 0.3-0.4 or so, the higher the speed of the motor, the greater the duty cycle.
2, signal distribution
I factory production of inductor stepping motor to two, four-phase motor-based, two-phase motor mode of operation of two-phase four beat and two-phase eight beat two, the specific distribution is as follows: two-phase four beat, the step angle of 1.8 degrees; two-phase eight beat, the step angle of 0.9 degrees. Four-phase motor work also has two kinds, four-phase four beat for AB-BC-CD-DA-AB, step angle of 1.8 degrees; four-phase eight beat for AB-B-BC-C-CD-D-AB, (step angle of 0.9 degrees).
3, power amplification
Power amplification is the most important part of the drive system. Stepping motor torque at a certain speed depends on its dynamic average current rather than static current (and the current on the sample are static current). The larger the average current, the larger the motor torque, to achieve a large average current which requires the drive system to try to overcome the motor's reverse potential. Therefore, different occasions to take different drive mode, so far, the drive mode generally have the following kinds: constant voltage, constant voltage series resistance, high and low voltage drive, constant current, fine fractions and so on.
In order to maximize the dynamic performance of the motor, the signal distribution, power amplification composed of stepper motor drive power. I plant the production of SH series two-phase constant current chopper drive power supply and microcontroller and motor wiring diagram is as follows:
Description:
CP to receive the CPU pulse signal (negative signal, low-level active)
OPTO to receive the CPU +5V
FREE offline, connected to the CPU ground, the drive power supply does not work
DIR Direction Control, connected to CPU ground, motor reversal
VCC DC power supply positive terminal
GND DC power supply negative terminal
A connects to motor lead red line
Connect to motor lead green line
B connects to motor lead yellow line
Connect to motor lead blue line Once the stepping motor has been finalized, its performance is dependent on the motor's drive power. The performance of the stepper motor depends on the motor drive. The higher the speed of the stepping motor, the higher the force distance, the higher the current of the motor and the higher the voltage of the driving power supply. Voltage impact on torque is as follows:
4, subdivision drive
In the stepper motor step angle can not meet the conditions of use, can be used to drive the stepper motor subdivision drive to drive the stepper motor, the principle of the subdivision drive is to change the size of the neighboring (A, B) current in order to change the synthesis of the angle of the magnetic field to control the stepper motor operation.
Four, the application of stepper motors
(a) the selection of stepper motors
stepper motors have a step angle (involving the number of phases), static torque, and the current of the three major elements. Once the three elements are determined, the stepper motor model is determined.
1, the choice of step angle
Step angle of the motor depends on the requirements of the load accuracy, the minimum resolution of the load (equivalent) converted to the motor shaft, each equivalent motor should go how many angles (including deceleration). The step angle of the motor should be equal to or less than this angle. Currently on the market stepper motor step angle is generally 0.36 degrees / 0.72 degrees (five-phase motor), 0.9 degrees / 1.8 degrees (two-phase, four-phase motors), 1.5 degrees / 3 degrees (three-phase motors) and so on.
2, static torque selection
The dynamic torque of the stepper motor is difficult to determine all of a sudden, we tend to determine the static torque of the motor. Static torque selection is based on the motor work load, and the load can be divided into inertial load and friction load two kinds. A single inertial load and a single friction load does not exist. When starting directly (generally from low speed), both types of loads should be considered, when accelerating the start of the main inertial loads, constant speed operation into as long as the friction load is considered. In general, the static torque should be 2-3 times the friction load within the good, static torque once selected, the motor's base and length will be able to determine down (geometric dimensions)
3, current selection
static torque of the same motors, due to the different parameters of the current, the operating characteristics of the difference is very large, based on the moment-frequency characteristic curve diagrams, to determine the motor's current (with reference to the drive power supply, and drive)
4, torque and power conversion
stepping motors are generally used in a wide range of speed, its power is changing, generally only measured by the torque, torque and power conversion is as follows:
P= Ω?M Ω = 2π?n/60 P=2πnM/60
P is the power unit of the watt, Ω is the angular velocity per second, unit of radians, n is the power per minute, Ω is the angular velocity per second, unit of radians, n is the power per minute. radians, n is the rotational speed per minute, M is the torque in newtons? meters
P=2πfM/400 (half-step work)
where f is the number of pulses per second (referred to as PPS)
(ii), the application of attention
1, stepper motors are used in low-speed occasions --- no more than 1,000 revolutions per minute, (6,666 PPS at 0.9 degrees), it is best to use in the 1000- 3000PPS (0.9 degrees) between the use of the motor can be made to work through the deceleration device, at this time the motor works efficiently, low noise.
2, stepping motor is best not to use the whole step state, the whole step state when the vibration is big.
3, due to historical reasons, only labeled as 12V voltage motor using 12V, other motor voltage value is not the drive voltage volts, according to the driver to choose the drive voltage (recommended: 57BYG using DC 24V-36V, 86BYG using DC 50V, 110BYG using higher than DC 80V), of course, 12 volts in addition to the 12V constant voltage drive can also use other drive power supply. Of course, the 12-volt voltage in addition to the 12V constant voltage drive can also be used in other drive power, but to consider the temperature rise.
4, the load of large moment of inertia should choose a large seat number motor.
5, the motor at higher speeds or large inertia loads, generally not in the working speed start, but the use of gradual increase in frequency speed, a motor does not lose step, the second can reduce the noise at the same time can improve the positioning accuracy of the stop.
6, high precision, should be mechanically decelerated, increase the motor speed, or the use of high fine points of the drive to solve the problem, you can also use 5-phase motors, but the price of the whole system is more expensive, fewer manufacturers, and its elimination of the argument is layman's terms.
7, the motor should not work in the vibration zone, if necessary can be solved by changing the voltage, current or add some damping.
8, the motor in the 600PPS (0.9 degrees) below the work, should be used small current, large inductance, low voltage to drive.
9, should
Step motor 14 questions
1. What is a stepper motor?
The stepper motor is an actuator that converts electrical pulses into angular displacement. In layman's terms, when a stepper driver receives a pulse signal, it drives the stepper motor to rotate a fixed angle (and step angle) in a set direction. You can control the number of pulses to control the amount of angular displacement, so as to achieve the purpose of accurate positioning; at the same time, you can control the frequency of pulses to control the speed and acceleration of motor rotation, so as to achieve the purpose of speed regulation.
2. What kinds of stepper motors are there?
There are three kinds of stepping motors: permanent magnet (PM), reactive (VR) and hybrid (HB)
Permanent magnet stepping is generally two-phase, smaller torque and volume, and the stepping angle is generally 7.5 degrees or 15 degrees;
Reactive stepping is generally three-phase, which can realize the output of large torque, and the stepping angle is generally 1.5 degrees, but the noise and vibration are great. In Europe and the United States and other developed countries in the 80's has been eliminated; hybrid stepping is a mixture of the advantages of permanent magnet type and reactive type. It is divided into two-phase and five-phase: two-phase stepping angle is generally 1.8 degrees and five-phase stepping angle is generally 0.72 degrees. This stepper motor is the most widely used.
3. What is Holding Torque?
HOLDING TORQUE is the moment at which the stator locks the rotor when the stepper motor is energized but not rotating. It is one of the most important parameters of a stepper motor, and usually the torque of a stepper motor at low speeds is close to the holding torque. Since the output torque of a stepper motor continues to decay with increasing speed, and the output power changes with increasing speed, the holding torque becomes one of the most important parameters for measuring a stepper motor. For example, when people say 2N.m stepping motor, in the absence of special instructions means a stepping motor with a holding torque of 2N.m.
4. What is DETENT TORQUE?
DETENT TORQUE is the moment at which the stator locks the rotor when the stepper motor is not energized.
DETENT TORQUE does not have a unified way of translation in China, which is easy to make people misunderstand; since the rotor of reactive stepper motor is not a permanent magnet material, it does not have DETENT TORQUE.
5. What is the precision of the stepper motor? Is it cumulative?
Generally the accuracy of a stepper motor is 3-5% of the step angle and is not cumulative.
6. How much temperature is allowed for the exterior of stepper motor?
The high temperature of stepping motor will firstly demagnetize the magnetic material of the motor, which will lead to the torque drop and even out of step, so the maximum temperature allowed for the exterior of the motor should depend on the demagnetization point of the magnetic material of the different motors; Generally, the demagnetization point of the magnetic material is more than 130 degrees Celsius, and some of them even up to more than 200 degrees Celsius, so the temperature of exterior of the stepping motor is completely normal at 80-90 degrees Celsius. Therefore, the temperature of the stepper motor exterior is 80-90 degrees Celsius, which is completely normal.
7. Why does the torque of a stepper motor decrease as the speed increases?
When the stepper motor rotates, the inductance of the winding of each phase of the motor will form a reverse electromotive force; the higher the frequency, the larger the reverse electromotive force. Under its action, the motor decreases in phase current with increasing frequency (or speed), resulting in a decrease in torque.
8. Why can the stepper motor run normally at low speeds, but if it is higher than a certain speed, it can not be started, and accompanied by whistling?
The stepping motor has a technical parameter: no-load start frequency, that is, the stepping motor can start the pulse frequency under no load, if the pulse frequency is higher than the value, the motor can not start normally, and may be lost step or blocked. In the case of a load, the starting frequency should be lower. If the motor to achieve high-speed rotation, the pulse frequency should have an acceleration process, that is, the start frequency is low, and then according to a certain acceleration up to the desired high frequency (motor speed from low to high speed).
9. How to overcome the vibration and noise of two-phase hybrid stepper motors at low speeds?
The vibration and noise of the stepper motor at low speed is its inherent disadvantage, which can be overcome by the following programs:
A. If the stepper motor happens to be working in the *** vibration zone, it can be avoided by changing the gear ratio and other mechanical transmission *** vibration zone;
B. Adopting the driver with subdividing function is the most commonly used and easiest way;
C. Switching to a hybrid two-phase stepping motor, how to overcome the vibration and noise in low-speed operation? p>C. Switch to stepping motors with smaller step angles, such as three-phase or five-phase stepping motors;
D. Switch to AC servo motors, which can almost completely overcome the vibration and noise, but at a higher cost;
E. Add magnetic dampers to the motor shaft, which is already available in the market, but with a larger change in mechanical structure.
10. subdivided drive fine points can represent the accuracy?
The stepper motor subdivision technology is essentially a kind of electronic damping technology (please refer to the relevant literature), its main purpose is to attenuate or eliminate the low-frequency vibration of the stepper motor to improve the motor's operating accuracy is only an incidental function of the subdivision technology. For example, for a two-phase hybrid stepping motor with a stepping angle of 1.8°, if the interpolation driver's interpolation number is set to 4, then the motor's operating resolution is 0.45° per pulse. Whether the motor's accuracy can reach or approach 0.45° also depends on other factors such as the precision of the interpolation current control of the interpolation driver. The precision of different manufacturers' interpolator drivers may vary greatly; the larger the interpolation score, the more difficult it is to control the precision.
11. four-phase hybrid stepper motor and driver series connection and parallel connection method what is the difference?
Four-phase hybrid stepping motors are generally driven by two-phase drivers, so the connection can be used in series or parallel connection to connect the four-phase motor into two-phase use. Series connection method is generally used in the motor speed of the occasion, this time the driver output current required for the motor phase current of 0.7 times, and thus the motor heat small; parallel connection method is generally used in the motor speed of the occasion (also known as high-speed connection method), the driver output current required for the motor phase current of 1.4 times, and thus the motor heat is larger.
12. How to determine the stepper motor driver DC power supply?
A. Determination of voltage: hybrid stepper motor driver power supply voltage is generally a wide range (such as IM483 power supply voltage of 12 ~ 48VDC), the power supply voltage is usually based on the motor's operating speed and response requirements to select. If the motor's operating speed is high or the response requirement is fast, then the voltage value is also high, but be careful that the ripple of the supply voltage should not exceed the maximum input voltage of the driver, otherwise the driver may be damaged.
B. Determination of current: the power supply current is generally based on the drive's output phase current I to determine. If a linear power supply is used, the power supply current can be taken as 1.1 to 1.3 times of I. If a switching power supply is used, the power supply current can be taken as 1.5 to 2.0 times of I.
13. Hybrid stepper motor driver offline signal FREE is generally used in what circumstances?
When the offline signal FREE is low, the current output from the driver to the motor is cut off and the motor rotor is in a free state (offline state). In some automation equipment, if direct rotation of the motor shaft is required without powering up the drive (manual mode), the FREE signal can be set low to take the motor offline for manual operation or adjustment. After the manual is completed, the FREE signal is set high again to continue the automatic control.
14. If there is a simple way to adjust the direction of rotation of a two-phase stepper motor when it is energized?
Just swap A+ and A- (or B+ and B-) of the motor and driver wiring.
About the driver of the subdivision principle and some related instructions (reproduced)
In foreign countries, for the stepping system, the main use of two-phase hybrid stepping motor and the corresponding subdivision driver.
But at home, the majority of users on the "subdivision" is not particularly understand, some just think that the subdivision is to improve the precision
degree, in fact, not, the subdivision is mainly to improve the motor's operating performance, is described as follows: the subdivision control of the stepping motor is controlled by the driver to accurately control the stepping motor's phase current to realize, the two-phase motor as an example, the stepping motor is a two-phase hybrid stepping motor and corresponding drive. Realization of the two-phase motor, for example, if the motor's rated phase current of 3A, if you use a conventional driver (such as the commonly used constant-current chopper) to drive the motor, the motor runs every step, the current in the winding will be mutated from 0 to 3A or mutated from 3A to 0, a huge change in the phase current will inevitably cause the motor to run the vibration and noise. If the use of subdivided drive, in the state of 10 subdivided drive the motor, the motor runs every micro-step, the current change in its winding is only 0.3A rather than 3A, and the current is a sinusoidal curve law changes, so that the motor vibration and noise is greatly improved, therefore, the advantages in performance is the real advantages of subdivided. As the subdivided drive to accurately control the phase current of the motor, so the drive to have a fairly high technical requirements and process requirements, the cost will also be higher. Note that some domestic drivers use "smooth" to replace the subdivision, some also known as subdivision, but this is not the real subdivision, hope that the majority of users must distinguish between the two essentially different:
1. "Smooth" does not accurately control motor phase current, but only the current of the motor, and the motor is not the same. Phase current, but only the rate of change of the current to slow down some, so the "smooth
Smooth" does not produce micro-steps, and subdivided micro-steps can be used to accurately determine the position.
2. The phase currents of the motor are smoothed, which causes a drop in motor torque, while subdivision control not only does not cause a drop in motor torque, but on the contrary, the torque will increase.
I am stepping not only newbie, I also come to post.
1. What is a stepper motor?
A stepper motor is an actuator that converts electrical pulses into angular displacement. In layman's terms: when a stepper driver receives a pulse signal, it drives the stepper motor to rotate a fixed angle (and step angle) in a set direction. You can control the number of pulses to control the angular displacement, so as to achieve the purpose of accurate positioning; at the same time, you can control the pulse frequency to control the speed and acceleration of motor rotation, so as to achieve the purpose of speed regulation.
2. What kinds of stepper motors are there?
There are three types of stepper motors: permanent magnet (PM), reactive (VR) and hybrid (HB)
Permanent magnet stepping is generally two-phase, torque and volume is small, the stepping angle is generally 7.5 degrees or 15 degrees;
Reactive stepping is generally three-phase, large torque output can be achieved, the stepping angle is generally 1.5 degrees, but the noise and vibration are very large. In Europe and the United States and other developed countries in the 80's has been eliminated; hybrid stepping refers to a mixture of permanent magnet type and the advantages of the reaction type. It is divided into two-phase and five-phase: two-phase stepping angle is generally 1.8 degrees and five-phase stepping angle is generally 0.72 degrees. This stepper motor is the most widely used.
3. What is Holding Torque?
HOLDING TORQUE is the moment when the stator locks the rotor when the stepper motor is energized but not rotating. It is one of the most important parameters of a stepper motor, and usually the torque of a stepper motor at low speeds is close to the holding torque. Since the output torque of a stepper motor continues to decay with increasing speed, and the output power changes with increasing speed, the holding torque becomes one of the most important parameters for measuring a stepper motor. For example, when people say 2N.m stepper motor, in the absence of special instructions refers to the holding torque of 2N.m stepper motor.
4. What is DETENT TORQUE?
DETENT TORQUE is the moment at which the stator locks the rotor when the stepper motor is not energized.
DETENT TORQUE does not have a unified way of translation in China, which is easy to make people misunderstand; since the rotor of reactive stepper motor is not a permanent magnet material, it does not have DETENT TORQUE.
5. What is the precision of the stepper motor? Is it cumulative?
Generally the accuracy of stepper motor is 3-5% of the step angle and it is not cumulative.
6. How much temperature is allowed for the exterior of the stepper motor?
The high temperature of the stepper motor will first demagnetize the magnetic material of the motor, which will lead to torque drop and even out of step, so the maximum temperature allowed on the motor exterior should depend on the demagnetization point of the magnetic material of the different motors; Generally, the demagnetization point of the magnetic material is more than 130 degrees Celsius, and some of them even up to more than 200 degrees Celsius, so the temperature of the stepper motor exterior is completely normal in the range of 80-90 degrees Celsius. Therefore, the temperature of the stepper motor exterior is 80-90 degrees Celsius, which is completely normal.
7. Why does the torque of a stepper motor decrease as the speed increases?
When the stepper motor rotates, the inductance of each phase of the motor winding will form a reverse electromotive force; the higher the frequency, the larger the reverse electromotive force. Under its action, the motor with the increase in frequency (or speed) and the phase current decreases, resulting in a decrease in torque.
8. Why can the stepper motor run normally at low speeds, but if it is higher than a certain speed, it can not start, and accompanied by a whistling sound?
The stepper motor has a technical parameter: no-load start frequency, that is, the stepper motor in the no-load situation can start the pulse frequency, if the pulse frequency is higher than the value, the motor can not start normally, may occur step loss or blocking. In the case of a load, the starting frequency should be lower. If the motor to achieve high-speed rotation, the pulse frequency should have an acceleration process, that is, the start frequency is low, and then according to a certain acceleration up to the desired high frequency (motor speed from low to high speed).
9. How to overcome the vibration and noise of two-phase hybrid stepper motors at low speeds?
The vibration and noise of stepper motor at low-speed rotation is its inherent shortcomings, generally can be used to overcome the following programs:
A. If the stepper motor happens to be working in the *** vibration zone, you can change the gear ratio and other mechanical transmission to avoid the *** vibration zone;
B. The use of the driver with subdividing function, which is the most commonly used, the easiest way;
C. Switch to a two-phase hybrid stepper motor at low-speed operation, the vibration and noise of the motor is the most common, the most convenient method;
Stepping motor is the most common method. p> C. Replacement with stepper motors with smaller step angles, such as three-phase or five-phase stepper motors;
D. Replacement with AC servo motors, which can almost completely overcome the vibration and noise, but at a higher cost;
E. Adding a magnetic damper on the motor shaft, which is already available in the market but with a larger change in the mechanical structure.
10. subdivided drive fine points can represent the accuracy?
The stepper motor subdivision technology is essentially an electronic damping technology (please refer to the relevant literature), its main purpose is to attenuate or eliminate the low-frequency vibration of the stepper motor to improve the motor's operating accuracy is only an incidental function of the subdivision technology. For example, for a two-phase hybrid stepping motor with a stepping angle of 1.8°, if the interpolation driver's interpolation number is set to 4, then the motor's running resolution is 0.45° per pulse. Whether the motor's accuracy can reach or approach 0.45° also depends on other factors such as the precision of the interpolation current control of the interpolation driver. Different manufacturers of interpolated drive precision may vary greatly; the larger the interpolated score, the more difficult to control the precision.
11. four-phase hybrid stepper motor and driver series connection and parallel connection method what is the difference?
Four-phase hybrid stepper motors are generally driven by two-phase drivers, so they can be connected in series or parallel to connect the four-phase motor to two-phase use. Series connection method is generally used in the motor speed of the occasion, this time the drive output current required for the motor phase current of 0.7 times, and thus the motor heat small; parallel connection method is generally used in the motor speed of the occasion (also known as high-speed connection method), the drive output current required for the motor phase current of 1.4 times, and thus the motor heat is larger.
12. How to determine the DC power supply of the stepper motor driver?
A. Determination of the voltage: hybrid stepper motor driver power supply voltage is generally a wide range (such as IM483 power supply voltage of 12 ~ 48VDC), the power supply voltage is usually based on the motor's operating speed and response requirements to choose. If the motor working speed is high or the response requirement is fast, then the voltage value is also high, but be careful that the ripple of the supply voltage can not exceed the maximum input voltage of the driver, otherwise the driver may be damaged.
B. Determination of current: the power supply current is generally based on the drive's output phase current I to determine. If a linear power supply is used, the power supply current can be taken as 1.1 to 1.3 times of I. If a switching power supply is used, the power supply current can be taken as 1.5 to 2.0 times of I.
13. Hybrid stepper motor driver offline signal FREE is generally used in what circumstances?
When the offline signal FREE is low, the current output from the driver to the motor is cut off, and the motor rotor is in a free state (offline state). In some automation equipment, if direct rotation of the motor shaft (manual mode) is required without powering up the drive, the FREE signal can be set low to take the motor offline for manual operation or adjustment. After the manual is completed, the FREE signal is set high again to continue the automatic control.
14. If there is a simple way to adjust the direction of rotation of a two-phase stepper motor when it is energized?
Simply align A+ and A- (or B+ and B-) of the motor and driver wiring.