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1、附錄 A 英文文獻(xiàn)原文Development of a Novel Drive Topology for a Five Phase Stepper MotorT.S. Weerakoon and L. Samaranayake(Dept. of Electrical and Electronic Engineering, Faculty of Engineering, University of Peradeniya, Sri Lank

2、a)[Abstract] In this paper, a novel drive topology for a five phase stepper motor is described in detail. Commercially off the shelf, low cost, standard stepper motor drive ICs are used to derive a novel drive topology f

3、or five phase stepper motors which enables closed loop speed and position control powered by inner current control loop. It is proved that the derived topology can be generalized to any stepper motor with higher odd numb

4、er of phases. The designed driver consists of full step, half step, clockwise and counter clockwise drive modes with the speed control and current control. [key words] Five-phase stepper motor, the return drive, speed co

5、ntrol, multi-modeI. INTRODUCTIONIn most of the robotics and automation engineering designs various types of stepper motors are used to obtain the required motion profiles. Stepper motors are preferred, as they do not req

6、uire frequent maintenance and due to their ability to operate in many harsh environments. Selection of the motors and their drive circuits depend on the required performance characteristics of the applications. The two p

7、hase and four phase stepper motors are the most common types available in the market.However, for applications requiring high precision, low noise and lower vibration, Five Phase Stepper Motors are used. Due to smaller s

8、tep angle, five phase stepper motors offer higher resolution, lower vibration and higher accelerations and decelerations. Therefore it is essential to make sure that these motor characteristics can be obtained from the d

9、esigned drive topology.Because the five phase stepper motors are a rarely used type in the robotic applications and the construction is typically complicated, it is very difficult to find driver ICs, which are manufactur

10、ed exclusive for them. As a result, the available Driver circuits for five phase stepper motors are very expensive.Using the available drive control ICs manufactured for common kinds of stepper motors such as 2 phased an

11、d 4 phased and using them in modeling new driver topology for other stepper motors would be a cost effective approach.The IC L297 integrates all the control circuitry required to control bipolar and unipolar stepper moto

12、rs. The L298N dual H bridge drive forms a complete microprocessor to stepper motor interface. Here, novel drive topology is investigated and developed for five phase stepper motors by adding a microprocessor and logical

13、control system with L297 and L298N. The complete topology is described in this paper.Section II explains the component characteristics. Section III is on the control logic circuit design phenomena. The interface design i

14、s given in Section IV with results in Section V. Finally the conclusions are presented in Section VI.II. CHARACTERISTIC ANALYSIS OF MAIN COMPONENTSThe IC L297 can be used with an H bridge driver IC for motor drive applic

15、ations as shown in Fig.1.1. In this design H bridge function is achieved from the L298N or L293E. This may change D = Ton / (Ton + Toff),where the Ton and Toff are switch on and off durations respectively of the H bridge

16、.In the chopper circuit, the flip-flop is set by each pulse from the oscillator, enabling the output and allowing the load current to increase. As it increases the voltage across the sensing resistor increases and when t

17、his voltage reaches Vref the flip-flop is reset, disabling the output until the next oscillator pulse arrives. In this method Vref determines the peak load current.The L298N is a monolithic circuit contains two H bridges

18、. In addition, the emitter connections of the lower transistors are brought out to external terminals allowing the connection of current sensing resisters.QQSETCLRSRV-refcomparatorV-senseFrom OSCFig. 2.2 Circuit containi

19、ng the flip-flop, the oscillator and the comparator used for current controllingB. CURRENT CONTROL IN INHIBIT CHOPPER MODEInhibit chopper control mode and phase line chopper control mode are two of the most common types

20、 of current control techniques available. In the latter case when the voltage across the sensing resistor reaches to Vref, only the low side switch is made off. Hence this method is not suitable and inhibit chopper contr

21、ol mode has to be used. The required switching sequences for this can be taken directly from L297.Inhibit chopper mode can be selected by pulling down (grounded) the CONTROL input signal of L297. Then chopper acts on INH

22、 to control the current through the motor coils. Therefore the contribution of INH signal generated from L297 is very important to create ENABLE signal for L298N. In the case when the voltage across the sensing resister

23、reaches to Vref, the chopper flip-flop is reset and INH is activated and is brought to low. Then it turns off all four switches of the bridge. The chopping frequency is determined by the internal oscillator of the L297.

24、After switching off all transistors, the diodes provide a path to divert the winding current. The switches of the H bridge are made on in the next oscillator cycle.III. LOGIC CIRCUIT DESIGNINGIn any mode of operations, w

25、ave patterns of A, B, C and D phases of the L297 repeat after four clock cycles as shown in Fig.3.1. Translation of the repetition of the phase waveform after the ten clock cycles is essential to derive the drive topolog

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