Łukasz WARGUŁA, Jarosław M. ADAMIEC, Piotr KRAWIEC, Konrad J. WALUŚ THE INVESTIGATION OF THE EFFECT OF TEMPERATURE ON THE CHARACTERISTICS OF THE STEPPER MOTOR IN THE ASPECT OF TRAFFIC GENERATION PERIODICALLY-VARIABLE The aim of the research is to analyze the influence of temperature on the characteristics of stepper motor. The research results will be used to assess the suitability of the stepper motor, as generator of motion periodically-variable. The example of the application of generators of motion periodically-variable are mills, crushers, crushing or transporting uniform motion machines. The test results will also be used in the assessment of the applicability of a stepper motor as a generator of motion periodically-variable to create a stand for experimental studies of belt transmission. The tests were conducted with the use of a universal test stand, consisting of sensors, torque and rotational speed. The loads have been applied by a brake with a magnetorheological liquid. INTRODUCTION The development and prevalence of stepper motor allows to replace classical motion generators with nonstandard drives with atypical kinematic and dynamic characteristics. The examples of such solutions can be periodically-variable motion generators which are called uneven transmissions [5-7]. The characteristic feature of these transmissions is to obtain the periodically variable shaft speed driven at constant speed of active shaft. Such solutions enable to acquire cyclic transmission ratio at the time of one full rotation. The advantage of such solutions is to get stable and repetitive changes in the kinematic and dynamic characteristics regardless of the operating environment. The disadvantage of this concept is the need to design and produce each time the wheels (gears, pulleys, chain), of different geometrical features. The possibility of using stepper motors as generators of motion periodically-variable will be presented in this article. Each electrical appliance while working generates heat. For most motors the operating temperature is in the range of 0 C to 60 C. During exploitation by using maximal parameters it can achieve up to 80 C [8]. The use of the motor as a generator of traffic periodically-variable motion may lead to its operation in different temperatures, and this can have a significant impact on motor control. In this paper the effect of temperature will be assessed on the possibility of applying stepper motors as generators of traffic periodically-variable motion. 1. THE PURPOSE OF RESEARCH The aim of the research was to analyze the influence of temperature on the characteristics of the stepper motor in terms of its use as a periodically-variable motion generator, and the possibility of using this transmission for research of vibration analysis and parametric resonances of belt transmission with toothed belt [1-4, 9-10]. The use of adjustable variable motion generator will allow to simulate the operation of the mills, whose job is crushing, grinding, separation or are destined to transport products using non-uniform movements. 2. RESEARCH STAND The study was conducted on a universal test stand designed to research belt transmission. The test stand is a part of equipment of transmission laboratory of Chair of Basics of Machine Design at Poznan University of Technology. It also enabled the research of kinematic and dynamic features of guild stepper motors (Fig. 1). The main element of the test is a stepping motor 2-phase WOBIT 110BYGH601 controlled via the controller Ledshine Mikrostep Drive ND2282PbF. Motor control signals are generated by the develop- Fig. 1. Reaserch stand: 1 - stepper motor, 2 - torquemeter, 3 - brake with magnetorheological fluid 4 - encoder, 5 - motor controler 12/2016 AUTOBUSY 1409
ment platform ARDUINO UNO. To the infliction of the engine load there was used a brake RH-90-4/20 with magnetorheological fluid. Torque measurement was carried out using a universal torquemeter designed by a team of the Chair of Basics of Machine Design. To register the change of the angular speed of shaft encoder MEGA- TRON MOB 2500/5/BZ/N was used. The results of measurements of torque and angular velocity were recorded in the original computer program which is an integral part of the test stand. The temperature was monitored by IR thermometer Fluke 62 Mini. 3. RESEARCH METHODOLOGY Stepper motor research was conducted in two stages. In the first stage the maximum speed of the stepper motor was determined at a known temperature (25 C, 55 C, 75 C) and the type of control a step motor (full-stepper, half-step to microstep 1/4). The rotation speed was fluently regulated from the very low to the very high until stopping with the use of module ARDUINO UNO. This reaserch was also divide into two stages with load and no-load of stepper motor and the loads have been applied by a magnetorheological brake. The simultaneous measurement of the torque made it possible to record the instantaneous changes of obtained drive characteristics allowing the evaluation of the oscillations generated depending on the temperature, rotation speed, type of stepping motor and system load. In the second stage time and the value of the maximum torque achieved during the dynamic load of the motor brake (until it is stopped) was detrmined. The test was performed for a constant speed of about 400 rpm at different temperatures and different kinds of the motor step control modes. 4. RESEARCH RESULTS The research characteristics of stepper motor take into account the effect of temperature on the characteristcs such as: the maximum speed (Fig. 2), the maximum torque (Fig. 3) and the time to reach maximum torque (Fig. 4). Research of torque of stepper motor unloaded at different control modes and different tempera- Fig. 2. Characteristics of the effect of temperature on the maximum speed of the motor depending on the step control Fig. 3. Characteristics of the effect of temperature on the maximum torque of the motor depending on the step control 1410 AUTOBUSY 12/2016
tures during the growing rotation speed is shown in Figure 5, indicating the occurrence of vibration. The research of torque of stepper motor loaded with different control modes and different temperatures during the growing rotation speed is shown in Figure 6, indicating the occurrence of vibration. Fig. 4. Characteristics of the effects of temperature on the time to reach maximum torque, depending on the type of control Fig. 5. Effect of temperature on the vibrations generated during the growth of the unloaded engine speed, depending on the type of control step (red line- torque, black line- speed) 12/2016 AUTOBUSY 1411
5. THE ANALYSIS OF RESULTSTHE RESEARCH Maximum rotation speed of stepper motor does not dependent mainly on its temperature (Fig. 2). Motor load influenced the values of obtained rotation speed. Type of control also had influence on obtained speed. Microstep steering with 1/4 step ensures the highest rotation speed, the next is full and half step control. The reason for this may be to reduce the moment of inertia of the rotor by reducing energy delivered during the execution of a step. The maximum torque of stepper motor for speed of about 400 rpm during dynamic braking of the wheel is equal to 16.7 to 15.7 Nm (Fig. 3). Discrepancies depend on the type of control, and here also microstep control 1/4 allows to get the highest torque value. It can be concluded that the temperature affects the obtained moment of not more than 0.5 Nm, but the trend cannot be evaluated because the results are inconclusive. Time to reach the torque is in the range of 0.01 s, and is illustrated in Figure 4. The significant effect achieved at the time of torque control step has a type of the motor, not the temperature. Microstep control allows to achieve a maximum torque in the shortest time, and control full-stepper need more time to reach maximum torque. In addition, full-stepper control beyond the longest time achieving maximum torque reaches its lowest value in contrast to the control microstep whose value is highest, and time the shortest. Registration of the torque of the loaded and unloaded indicated torque oscillations (Fig. 5 and 6). Instantaneous change of drive characteristics generated during the growth rotation speed zones show the resonant frequency of the stepper motor. The speed at which the resonance is the greatest should be avoided during the design process operation of the stepper motor. Temperature prevents the occurrence of zones of resonance. The main factor affecting the resonance zone is the engine load and speed. Type of control limits mark the greatest resonance. The speed at which the oscillations were the smallest type of control reduced slightly. Microstep regardless of load drive allows for low resonance throughout the rev range. SUMMARY The experimental research have demonstrated that the temperature (25 C- 75 C) within the range of normal operation of the stepper motor 2 phase Wobit 110BYGH601 does not affect the Fig. 6. Effect of temperature on the vibrations generated during the growth of engine speed loaded depending on the type of control (torque line- red, black line- speed) 1412 AUTOBUSY 12/2016
essential parameters used during the drive signal of periodicallyvariable motion. Parameters such as minimum and maximum motor speed, the occurrence of zones of the resonant operating frequencies of the stepper motor, boot time and stopping the motor, the value of the generated torque are definitely more dependent on the load and the type of control. An increased value of the oscillation of torque stepper motor while working in the periodically variable move can significantly disrupt the other recorded vibration signals. It can be concluded that the resonance of the stepper motor will prevent measurement of parametric resonance toothed belt tensioning gear. Further research will be conducted in the analysis of the impact of dynamic periodically-variable control signals on obtained characteristics of guild kinematic and dynamic transmission. BIBLIOGRAPHY 1. Abrate S.: Vibration of belts and belt driver., Mechanism and machine theory, Research Gate, DOI: 10.1016/0094-114X(92)90064-O November 1992 2. Chowdhuty S.: Effect of Shaft Vibration on the Dynamics of Gear nad Belt Driver., Dissertation Presented in Partial Fulfillment of the Requirement of the Degree Doctor of Philosophy in the Graduates School of The Ohio State University, 2010 3. Ji J., Jang M. J., Kwon O. E., Chai M. J., Kim H. S.: Power transmission dynamics in micro and macro slip regions for a metal v-belt continuously variable transmission under external vibrations., International Journal of Automotive Technology, Vol. 15, No. 7, pp. 1119-1128 (2014) DOI 10.1007/ s12239-014- 0116-5 4. Krasiński M., Stachoń S.: Badania dynamiczne przekładni pasowej z pasami zębatymi/ Dynamic tests of toothed belt transmission. Czasopismo Techniczne. Mechanika, Wydawnictwo Politechniki Krakowskiej, 12-M/2004 ISSN 0011-4561 5. Krawiec P., Adamiec J., Waluś K.J., Przekładnie cięgnowe o zmiennym przełożeniu z pasem zębatym., Logistyka / Instytut Logistyki i Magazynowania. - 2014, nr 6, s. 6026-6031. - CD-ROM 3, 2014, p-issn: 1231-5478 6. Manin L., Besson F., Michon G., Dufour R.: Experimental investigation on the dynamic characteristics and transverse vibration instabilities of transmission belts. 7. Michon G., Manin L., Parker R. G., Dufour R.: Duffing oscillator with parametric excitation: analytical and experimental investigation on a belt-pulley system., Journal of Computational and Nonlinear Dynamics, July 2008, Vol. 3/ 031001-1 8. Ober W. Teoria napędów krokowych. WOBIT, wyd 21.06.2017 http://www.wobit.com.pl 9. Osiński J.: Analiza drgań parametrycznych układów cięgnowych poddanych stałemu obciążeniu poprzecznemu z zastosowaniem metody asymptotycznej i metody elementów skończonych. Mechanika Teoretyczna i Stosowana 2, 23 (1985) 10. [Zhang L., Zu J. W.: Non-linear vibrations of viscoelastic moving belts, part I: free vibration analysis., Journal of Sound and Vibration (1998) 216(1), 76-91, Article No. sv981688 The investigation of the effect of temperature on the characteristics of the stepper motor in the aspect of traffic generation periodically-variable The aim of the research is to analyze the influence of temperature on the characteristics of stepper motor. The research results will be used to assess the suitability of the stepper motor, as generator of motion periodically-variable. The example of the application of generators of motion periodically-variable are mills, crushers, crushing or transporting uniform motion machines. The test results will also be used in the assessment of the applicability of a stepper motor as a generator of motion periodically-variable to create a stand for experimental studies of belt transmission. The tests were conducted with the use of a universal test stand, consisting of sensors, torque and rotational speed. The loads have been applied by a brake with a magnetorheological liquid. Autorzy: mgr inż. Łukasz Warguła Poznan University of Technology, Poznan, Poland, lukasz.wargula@put.poznan.pl dr inż. Jarosław M. Adamiec Poznan University of Technology, Poznan, Poland, jarosław.adamiec@put.poznan.pl dr hab. inż. Piotr Krawiec prof. PP Poznan University of Technology, Chair of Basic of Machine Design, Piotrowo street 3, 60-965 Poznan, Poland, piotr.krawiec@put.poznan.pl dr inż. Konrad J. Waluś Poznan University of Technology, Poznan, Poland, konrad.waluś@put.poznan.pl 12/2016 AUTOBUSY 1413