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Control method of stepping motor acceleration and deceleration based on single chip microcomputer Li Shizhong, Lei Xiu Inner Mongolia University of Technology, Inner Mongolia Hohhot 0i0062 plus speed discrete control method. The method is verified by experiments to solve the problem of the out-of-step blocking noise in the fast acceleration and deceleration control of stepping motor.
The stepping motor has the characteristics of fast stopping capability, high strength and high speed, and is widely used in industrial process control and instrumentation. However, during the actual operation, due to improper start and stop control, the stepping motor will have jitter at start-up and overshoot at stop, which affects the control accuracy, especially when the stepper motor is frequently started and stopped. More obvious.
Therefore, the fast start and stop control of the stepping motor is still in the technical course of the research. The start-stop control of the stepping motor is studied. A discrete control method for stepping motor acceleration and deceleration based on single-chip microcomputer control is proposed. After many runs, the expected goal is achieved.
1 Acceleration and deceleration curve The operation of the stepper motor is usually accelerated by a constant speed deceleration phase. The stepper motor acceleration and deceleration curve is in the middle, the ordinate is the frequency, the unit is pulse seconds or step seconds, which is essentially speed, and the abscissa is time, in seconds. After the stepper motor starts at the frequency, it accelerates with acceleration, reaches the highest operating frequency after the time, and then travels at a speed to the moment to accelerate.
Deceleration, the motor stops at the moment, the total number of steps is to repeat the previous process after staying for 1! 5 seconds. The acceleration from standstill to the maximum operating frequency and from the highest operating frequency to the stop is the key to control, usually with uniform acceleration and uniform deceleration control.
It can be seen from 1 that the acceleration phase is a linear acceleration process, in which the relationship between frequency and time can be the agricultural rate; 3 is the acceleration segment; 1 is the acceleration time.
2 Discretization of the acceleration and deceleration process 跬 跬 跬 跬 昙 昙 昙 昙 麇 麇 麇 麇 麇 麇 麇 麇 麇 麇 麇 跬 麇 麇 麇 麇 麇Indefinitely, every step is counted. 1 loading value, you can use the step curve to approach the acceleration and deceleration curve 2, 2, using the discrete method to discretize the acceleration and deceleration curve, after the discretization, the speed is increased by the bin, and each gear must be kept in the step. Keeping this speed stable after running several pulses before upgrading, this overcomes the speed lag caused by the moment of inertia of the stepper motor rotor, and can only accelerate rapidly after the actual running speed is reached. In fact, this is also the local speed error. Automatic correction.
It can be known from Equation 1 that the algorithm is the actual control system. When the most commercial operating frequency is 1, the equation can be calculated by the equation 21 to accelerate the acceleration segment evenly. The first time is called the first time. The time interval between the two speed changes of the neighbors is the receiving date of December 27, 2004, and the energy consumption identification and high-efficiency transmission technology is 200090202. The number of steps in the operation of the science and technology horse in Inner Mongolia is accelerated to the total number of steps. In order to write the program, according to the requirements of the controlled system for the stepping motor acceleration time, calculate the number of divisions and the number of steps in each gear, and then check in descending mode. When the number of steps in the first gear is reduced to zero, in this file After the number of steps has been completed, enter the + mouse to continue the previous process, run straight until the total number of bins is zero, and the acceleration process is completed. The above is the processing method for the acceleration process, and the deceleration process is related to it.
3 Control of stepper motor based on single-chip microcomputer 3.1 Basic principle Meter with single-chip microcomputer to step-by-step motor acceleration/deceleration control, in fact, is to change the time interval of output pulse, MCU control stepper motor addition and subtraction operation method And the two soft secondary methods of hardware refer to the frequency of the pulse output by the delay delay program. The length of the delay is dynamic. The software method in the motor control must continuously generate the control pulse, which takes up a lot of , time, make. The chip machine can't be used for other hardware methods. It depends on the internal timer of the MCU. Every time it enters the limit, it interrupts and changes the constant constant, so that the pulse frequency is gradually increased when the speed is increased. The pulse frequency is gradually reduced during deceleration. This method takes less time. Can be implemented in a variety of microcontrollers.
It is a kind of speed control method.
Taking into account the needs of the microcontroller 1 and the actual work. The entire process of dynamic acceleration is completed in 255 bins. When the actual required speed changes with each execution of the task, the program can be calculated according to the maximum speed of the work object.
Each time you perform a task, you first need to determine the number of steps in the step, which can be divided according to step 816. The measurement standard is to achieve high speed and ensure a low running voice without losing the step.
3.2 Determination of timing constants The key to the discrete control of stepping motor acceleration and deceleration is the determination of the number of timing delays. It can be seen from Equation 5 that the timer period 1 of each speed step is when the used crystal oscillator frequency = 6 cubits out and the timer is 16-bit timer 1, then the reload value of the timer is implemented in 0 language as follows The timing time above TH=x256 is calculated according to the interrupt of the single-chip timer interrupt. If the timer is interrupted twice to send a complete pulse calculation, the timing time should be half of the equation 8.
4 experiment 4.1 hardware line called control using 21350034 stepper drive to drive 1 phase hybrid stepper motor 6 milk 1550 hardware circuit such as 4.2 soft cow design software written in 0 language 0514, mainly by the main function acceleration and deceleration screwing function and timing The interrupt service number is composed, the main function parameter definition and initialization of the main function, the function subroutine call; the acceleration/deceleration control function is used to set the pulse output enable flag, 1. For example, timer! The stop signal is timed out and the service program outputs a pulse. The acceleration/deceleration flag 1 is set and the division port number å© is changed. 1 å© also 妒. Among them, the force hook deceleration judgment, the condition is å©. , å©0 is the acceleration segment; segment. Due to space limitations, only the interrupt service flow is given in the text.
Inner Mongolia Science and Technology and Economic Application Nanocomposites Strengthening the Thermal Insulation of the Upper Part of the Electrolytic Cell The Production Equipment Department of Shenli Bao Aluminum Co., Ltd., the current state of the upper insulation layer of the 0140461 electrolytic cell in Baotou, Inner Mongolia, is the main equipment for electrolyzing alumina into aluminum. In order to ensure the normal production of tantalum electrolysis, the inside of the electrolytic cell must be placed at a high temperature. The thermal insulation of the upper part of the electrolytic cell is the most important measure. The most important thing is to place the groove on the upper part of the sputum tank for heat preservation, and then add aluminum silicate fiber layer to strengthen the insulation in the aluminum hood plate, but the effect is not Obviously, the specific amount is lost, which greatly increases the production cost; especially in the case of frequent power cuts due to power shortage, the electrolytic process parameters fluctuate greatly, which seriously affects the normal operation of electrolytic production; The increase in the benefits has a certain hazard to the health of the workers.
Advantages of 2 nanocomposites In view of the above, in order to save energy and reduce labor productivity, it is necessary to select a new type of insulation material as a substitute for existing products. By comparing the insulation effects of various insulation materials, we abandoned the choice of traditional pure thermal materials such as insulating brick mineral wool siliceous fiber, and finally decided to use nano composite reflective insulation materials.
5 Conclusions 0 According to the experimental verification, the discretization control can effectively solve the stepless noise in the stepping motor acceleration and deceleration control, which can be applied in practical engineering.
by. Language programming realizes the control of the single-chip microcomputer, which greatly speeds up the software development and shortens the development cycle. Moreover, the language can be easily transplanted by the single-chip microcomputer, which is beneficial to the re-selection of the single-chip microcomputer.
4 Ma Zhongmei and other editors. Single chip microcomputer. Language application design.
Beijing University of Aeronautics and Astronautics Press, 1997.