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In this paper a stepper tool for the Armed Bear Common Lisp (ABCL) implementation is proposed, describing its features and implementation related details. ABCL does not currently have a stepper and the addition of one can help improve the quality of the code designed to run in the implementation, and also it can be useful to assist in the debugging process of Common Lisp (CL) portable code. &nbsp

Stepper digunakan untuk melakukan perpindahan tegangan suplai pada power amplifier. Dimana pada stepper terdapat mosfet yang digunakan sebagai saklar dan terhubung pada beban (transistor final), apabila power amplifier membutuhkan suplai tegangan tinggi maka stepper akan mengkondisikan tegangan yang masuk ke transistor final berpindah dari suplai tegangan rendah menjadi suplai tegangan tinggi. Hal ini bertujuan agar disipasi daya pada power amplifier class AB dapat diminimalkan karena power amplifier class AB menggunakan satu catu daya secara konstan, mulai dari penguatan terkecil sampai terbesar hanya mengandalkan satu catu daya, sedangkan dengan menggunakan stepper catu daya yang digunakan lebih dari satu yaitu catu daya rendah (Low Voltage) dan pada daya tinggi (High Voltage) sama seperti catu daya pada power amplifier kelas G. Pada saat power amplifier digunakan pada volume yang kecil maka power amplifier akan dikondisikan pada tegangan suplai yang kecil pula (Low Voltage) sedangkan catu daya yang tinggi (High Voltage) tidak digunakan. begitu seballiknya apabila power amplifier digunakan pada volume yang besar maka power amplifier akan dikondisikan pada tegangan suplai yang tinggi (High Voltage). Stepper is used to transfer the supply voltage to the power amplifier. Where in the stepper there is a mosfet that is used as a switch and connected to the load (final transistor), if the power amplifier requires a high voltage supply, the stepper will condition the voltage entering the final transistor to move from a low voltage supply to a high voltage supply. It is intended that power dissipation in class AB power amplifiers can be minimized because class AB power amplifiers use one power supply constantly, starting from the smallest to the largest gain only relying on one power supply, while using a stepper power supply that used more than one, namely low voltagr and high voltage just like the power supply in class G power amplifiers. When the power amplifier is used at a small volume, the power amplifier will be conditioned at a small supply voltage (Low Voltage) while the high power supply (High Voltage) is not used. so vice versa if the power amplifier is used at a large volume, the power amplifier will be conditioned at a high supply voltage.

Hybrid stepper motors (HSMs) are a type of stepper motor that have both a magnet and teeth on their rotors. These actuators are used in very fields including automation and robotics. Although these motors have high torque densities, improving their performance, their torque density, and their response time is very essential and useful. The most important problem in HSMs is their heavy rotor. A weightier rotor means more rotor vibrations and oscillations for each step. Therefore, in this study two motors with new rotor structures are represented. The first one has a light cup-shaped rotor which improves motor response time and decreases rotor oscillation on each step, and the second one not only has these benefits but also has increased motor torque density noticeably, which is due to one extra teeth row on its rotor that has made it two motors in one structure, indeed. Finally, the results of these improvements are compared with the conventional HSMs performance. Comparisons proved the significant superiority of these two motors over conventional HSMs.

Piezo-stepping actuator is one device that produces large displacement while some voltage is applied to it or vice-versa by micro-meter accuracy and nanometer resolution. The displacement in stepper actuators happens with steps. A linear stepping movement of the base of the actuator is proposed in this paper. A linear stepping motion of the piezo actuators is achieved with four sets of push–pull actuators and four sets of lock release actuators. The designed stepper actuator produces linear displacements. The design and control of the stepper actuators are explained in the paper. A trapezoidal signal is being generated from the triangular wave moreover this is implemented as the input for the smooth functioning of a stepping actuator. Control operation of push–pull and lock-release actuators was performed and for various input displacements the experimental displacements of actuators were achieved and the results were plotted. Control operation of Push-pull and lock release assembly was conducted for varying input displacement and corresponding experimental displacement is measured and also the results were plotted. The actuator assembly was proficient in driving the linear guideways.

Picking numbers is arguably the most frequently performed input task on smartwatches. This paper presents three new methods for picking numbers on smartwatches by performing directional swipes, twisting the wrist, and varying contact force on the screen. Unlike the default number picker, the proposed methods enable users to actively switch between slow-and-steady and fast-and-continuous increments and decrements during the input process. We evaluated these methods in two user studies. The first compared the new methods with the default input stepper method in both stationary and mobile settings. The second compared them for individual numeric values and values embedded in text. In both studies, swipe yielded a significantly faster input rate. Participants also found the method faster, more accurate, and the least mentally and physically demanding compared to the other methods. Accuracy rates were comparable between the methods.

Multi-axis stepper motors offer a compact solution to actuate multiple degrees of freedom in a mechanical system by a single device. This research presents an electric stepper motor with three coaxial shafts driven by a single stator. The motor dimensions are 42 × 42 × 44 mm $^3$ (excluding output shafts), its mass is 0.326 kg and it includes three rotors of height 7 mm and different number of teeth. The maximum torque for one rotor at low speed and 1 A current is 0.10 N m, which is comparable to that of a conventional stepper motor with similar rotor size. When multiple rotors are driven simultaneously, then the total power has to be distributed over the three rotors, resulting in 42% lower torque on average. The maximum no-load speed is 4000 revolutions per minute. The coaxial output shaft configuration poses significant challenges but also unique opportunities in actuating multiple joints of a robotic system. In many applications, the mechanical design can be redesigned to make effective use of the multi-motor design. An example of a three-DOF robot arm is demonstrated that can be efficiently driven by the proposed motor.

A stepper motor is an actuator widely used in different areas for various purposes such as robots and CNC machines. This motor has 3 different types and the hybrid type is the most common and useful one. This paper has presented a new structure for conventional hybrid stepper motors (HSMs) that has improved the torque density dramatically and more than 200% compared with the conventional ones. This motor firstly is modeled on the computer and has been analyzed with a 3D finite element method (3D FEM) software. Then the results have been compared with the conventional motors and after the proof of its superiority, it is fabricated and the results of theoretical and practical tests are compared. These results confirm the advantages of the new structure for HSMs.

Laser Microfabrication (LMF) has been widely employed in a broad range of applications based on linear and nonlinear optics phenomena. Thus, this work aims to develop an Arduino-controlled low-cost LMF setup with high quality and precision. The LMF setup comprises a homemade optical microscope, a motorized 3-D translation stage based on low-cost stepper motors and current driver, and a relay module to control the hard disk shutter switch. We show that the microfabrication setup is capable of a precise XY translation motion with 25 mm travel range and scanning speeds as high as 1350 μm/s, with a resolution of 315 nm while presenting high precision and repeatability (tiny backlash

This paper deals with a computer vision and photosensor based two-axis solar tracking system for an active daylighting system. The real-time image processing was performed by using a Raspberry Pi 4 controller, and processed data were used as an input of an ATmega128 microcontroller to track the sun’s path. An active daylighting system requires a higher concentration of sunlight with an acceptable accuracy in different weather conditions. Alone, an image based or photosensor based control strategy cannot fulfill both requirements. Successful integration of two different feedback mechanisms could overcome the tracking difficulties. The system was composed of Raspberry Pi 4 and ATmega128 controllers, a camera, electronic circuits, and stepper motors. The proposed control system could distinguish the objects (e.g., sun or clouds) in front of the camera, and process the data required to run the solar tracker. The integration of extra photosensors and the camera was able to avoid the cloud disturbance. To investigate the efficacy of the solar tracker, it was integrated with the optical fiber cable to transmit harvested daylight for an indoor illumination.

Contribution: This article proposes a low-cost and mobile device-based learning support system for the stepper motor, which provides Web-based remote laboratory. This system allows young engineers to learn about rotational principles, control methods, and programming in stepper motors. Background: Familiarity with electrical machinery, such as motors, is an important factor for electric power engineers. Hands-on laboratories are the most effective and important learning method in the study of electrical machinery. However, the Hands-on laboratories require commitments of time, space, and significant number of expensive laboratory instruments. Intended Outcomes: In the proposed system, the students are free to repeat the experiment using a real stepper motor, for example, using a smartphone. This learning support system that combines remote laboratory and virtual laboratory is expected to be an easy-to-use for young engineers. Application Design: Proposed system consists of the low-cost microcomputers, such as raspberry Pi and Arduino, and does not use expensive software, such as LabVIEW and MATLAB. It has both low cost and compatibility with any mobile devices. Findings: The learning effectiveness and usability of the system were evaluated through questionnaires and tests for a total of 50 students at the authors’ department. Consequently, the results of the evaluation tests and questionnaires demonstrated that the proposed system will be useful to study the stepper motor.

The European Spallation Source (ESS) accelerator is composed of superconducting elliptical cavities. When the facility is running, the cavities are fed with an electric field from klystrons. Parameters of this field are monitored and controlled by the low-level radio frequency (LLRF) system. Its main goal is to keep the amplitude and phase at a given set point. The LLRF system is also responsible for the reference clock distribution. During operation, the cavities are periodically experiencing strain caused by the Lorentz force, while the high gradient of the electric field is generated for the beam acceleration. Even small changes in the physical dimensions of a cavity shift its resonance frequency. This phenomenon, called detuning, causes significant power losses. It is actively compensated by the LLRF control system, which can physically tune lengths of the accelerating cavities with stepper motors (slow, coarse-grained control) and piezo elements (active compensation during operation). This article describes the implementation and tests of the software supporting various aspects of the LLRF system and cavities management. The Piezo Driver management and monitoring tool is dedicated to a piezo controller device. The LO distribution application is responsible for configuration of the local oscillator. The cavity simulator tool was designed to provide access to properties of the hardware device, emulating behavior of the elliptical cavities. IPMI Manager Software was implemented to monitor the state of MicroTCA.4 crates, which are a major part of the LLRF system architecture. All applications have been created using the experimental physics and industrial control system (EPICS) framework and built in the ESS EPICS Environment (E3).

This work presents a comprehensive commissioning and workflow development process of a real‐time, ultrasound (US) image‐guided treatment planning system (TPS), a stepper and a US unit. To adequately benchmark the system, commissioning tasks were separated into (1) US imaging, (2) stepper mechanical, and (3) treatment planning aspects. Quality assurance US imaging measurements were performed following the AAPM TG‐128 and GEC‐ESTRO recommendations and consisted of benchmarking the spatial resolution, accuracy, and low‐contrast detectability. Mechanical tests were first used to benchmark the electronic encoders within the stepper and were later expanded to evaluate the needle free length calculation accuracy. Needle reconstruction accuracy was rigorously evaluated at the treatment planning level. The calibration length of each probe was redundantly checked between the calculated and measured needle free length, which was found to be within 1 mm for a variety of scenarios. Needle placement relative to a reference fiducial and coincidence of imaging coordinate origins were verified to within 1 mm in both sagittal and transverse imaging planes. The source strength was also calibrated within the interstitial needle and was found to be 1.14% lower than when measured in a plastic needle. Dose calculations in the TPS and secondary dose calculation software were benchmarked against manual TG‐43 calculations. Calculations among the three calculation methods agreed within 1% for all calculated points. Source positioning and dummy coincidence was tested following the recommendations of the TG‐40 report. Finally, the development of the clinical workflow, checklists, and planning objectives are discussed and included within this report. The commissioning of real‐time, US‐guided HDR prostate systems requires careful consideration among several facets including the image quality, dosimetric, and mechanical accuracy. The TPS relies on each of these components to develop and administer a treatment plan, and as such, should be carefully examined.

This article proposes a robust nonlinear position control for permanent magnet stepper motors. We develop a new single-input single-output model that consists of position, velocity, and acceleration using a commutation scheme to lump a system function and an external disturbance into a disturbance. An augmented observer is designed to estimate the position, velocity, acceleration, and disturbance. Because the disturbance refers to external disturbance, acceleration dynamics, and parameter uncertainties, it is difficult to accurately estimate disturbance without the high observer gain. It may result in the degradation of the position tracking performance. The nonlinear controller is then developed using backstepping to suppress the position tracking error using the input-to-state stability property. The key innovation of the proposed method is the design of the nonlinear gain to suppress the position tracking error according to the disturbance estimation error. Thus, the use of the high observer gain to accurately estimate the disturbance can be avoided. The proposed control algorithm was experimentally verified using the PM stepper motor control system and can be easily implemented in real-time using position measurements only.

In this research work, a firing control system is developed for the ZU-23-2 Russian anti aircraft gun prototype by integrating an image processor with helmet mounted cueing system. The combined action of the image processor and inertial measuring unit, which is mounted on operators helmet used here to generate actuation command for the motors. Actuators used in this research are two stepper motors for azimuth and elevation motion of the weapon; both are controlled by a PI controller. The overall proposed systems are deployed in the prototype hardware and tested with an experiment by varying the target range and the PI controller parameters. Finally, results show an improvement in performance in terms of speed (1.75 sec) and approximately a 82% accuracy of detection as well as in tracking by applying background subtraction in frame deference algorithm. In addition, the deployed stepper motor gives a response time of 0.005 sec for every change in position of the gunner head with 95% accuracy in input waveform tracking.

Twisted and coiled polymer muscles (TCPM) are inexpensive, light weight and simple artificial muscles that are introduced recently. For implementation of this muscle as a linear controllable actuator, we need an open loop or closed loop control system. In this paper we proposed a new artificial stepper tensile actuator based on joule-heated TCPM (we name it “stepper TCPM”) that will be used as a stepping straight actuator and can be control via an open loop control system. There are not any sensors in the proposed actuator, so the actuator can be used in an open loop control system for stepping linear movements. This stepper actuator consists of some serial TCPM string with some individual heater isolated wires that twisted around the fiber of each TCPM. The maximum displacement of each TCPM is double of the previous TCPM, therefore the full set or reset of current of these wires result full contraction of each TCPM and stepping displacement control of stepper TCPM. Our experiment shows that we can control step by step displacement of proposed actuator without any sensor or closed loop control system (similar to common stepper motor but in straight motion). Proposed actuator is applicable in low cost and low weight stepping movement mechanism.

An automotive transmission system is a system that has the function for conversion torsion and the rapidity (rotation) from the torsion machine and it has a different rapidity to keep on to the last activator. This conversion changes the high rotation speed becomes lower, but it has more energy conversely. The highest torsion in certain machines generally occurs in a half from the limit from the machine rotation which allowed, while the vehicle needs the highest torsion start from it could be moved. The purpose of this study is to modify the accuracy and the exact transmission, so that the activator transmission which uses a pulley system (part of the automobile chassis) and belt will have a gentle rotation by activator use motor stepper with more energy in it. This machine works by having a battery to supply electricity to the motor stepper, then it is controlled by azimuth and elevation moving control so that transmission of weapon bipod will move with elevation-100 s/d 600 degrees. Azimuth moving control will be pressed so it will move the motor stepper and make the weapon move to 360 degrees. The result of the rotation of the motor will move gently and the comparison between use motor DC gearbox which not really soft at the rotation itself.

Aiming at the complex characteristics of the sequential logic control system design, such as X-D diagram and karnaugh map method, a design method based on stepper module was proposed, the procedure of which does not need to be checked and corrected. The design of different pneumatic circuits was carried out with the automatic drilling machine as the application object. First, a stepper module composed of a two-position three-way valve and a dual-pressure valve was constructed, and its structure principle was analyzed in detail. Next, three kinds of stroke programs were listed by analyzing the working process of automatic drilling machine, which were multi-cylinder single reciprocating, multi-cylinder multi reciprocating and multi-cylinder multi-section reciprocating stroke program, and the pneumatic circuit control system was designed by the stepper module method. Finally, the pneumatic circuit was simulated and analyzed using the software Fluid-SIM. The simulation results showed that each actuator can complete the corresponding actions according to the design requirements, which verified the correctness and reliability of the stepper module design method. This work would provide a fast and effective method for the design of the sequential logic control system.

Flexible Manufacturing System (FMS) is one of the modern production systems that support the implementation of Industry 4.0. An educational institution plans to build an FMS model for learning the modern production systems. The FMS is a manufacturing system consisting of a set of automatic workstations connected to a material handling system where all activities are controlled by a computer system. The material handling system consists of a material storage system and a transportation system, one example of a transportation system is the stacker crane. In this research, the stacker crane model has been built which consists of three main components, which are the bottom frame, the mast, and the carriage. This component is equipped with stepper motors, leadscrews that are controlled by the micro controller and an application on Android. The stacker crane model is tested to retrieve and deliver the stereofoam material model to the destination which is controlled by the user using an application on Android. The characteristics of the stacker crane model can move the workpiece with a maximum error of 2 mm in the positive x-axis direction, 2 mm in the negative x-axis movement, up to 2 mm positive y-axis, downward at negative y-axis direction 2 mm.

In this research, a control system in the form of a syringe pump has been developed to control the volume and flow rate of a liquid or a solution. The syringe pump is fabricated by controlling the speed and pulse width modulation (PWM) of stepper motors based on the Arduino Uno microcontroller board. The tools used are a stepper motor as a syringe driver, the Arduino Uno as a controller, a four-digit seven-segment display and a keypad matrix as an input interface. The syringe pump works by pushing the injection pump whose speed has been adjusted to the flow rate. The speed of the flow rate and volume are obtained by setting the delay time of the stepper motor using PWM pins from the Arduino Uno. The syringe pump is observed to work in the flow rate range of 0.10–12.00 ml h–1. The system can be applied to medical settings as the control of volume and flow rate of drug fluids as well as with nanofibres using electrospinning technique.

This brief proposes an advanced positioning law for hybrid-type stepper motors with two main features: a) a combination of pole-zero cancellation-based proportional-integral control with disturbance observers and b) a variable manifold forced to be exponentially convergent by the proposed control law. The parameter and load uncertainties are also explicitly handled in the controller design task. The practical improvement is confirmed with experimental evidence using a 10-W stepper motor controlled by two dual half-bridge drivers and a 32-bit digital signal processor.

Stepper motors are used in robotic applications, industrial machines, and many different application areas. Mechanical resonance problems occur in the control of stepper motors at low speeds. In the control of robotic systems with nonlinear characteristics, conventional control methods are inadequate. Single link manipulators are the most basic structure used in the identification and control of the nonlinear load in robotic systems. In this study, the control of single link manipulator was performed using the stepper motor. As in a real system, the single link manipulator is modelled by connecting to the stepper motor via the gearbox. An Artificial Neural Network (ANN)-based NARMA-L2 controller was preferred for the control of the stepper motor. The NARMA-L2 controller offers superior performance especially in the control of nonlinear loads. Firstly, simulation of the single link manipulator and the stepper motor, which also included resonance moments, was carried out in the MATLAB/Simulink environment. Then the training data of the NARMA-L2 controller was created and the training process was realized. Position control of the stepper motor was performed in MATLAB/Simulink environment using conventional control method and NARMA-L2 controller. The simulation results were obtained at three different speeds and for different angle values. By comparing the conventional control method with the proposed control method, the superior performance of the NARMA-L2 controller in the speed and position control of the motor was demonstrated.

Aim: The goal is to present a new asynchronous principle of operation of stepper motors, based on the use of counter-rotating (or traveling) magnetic fields. Method: A change in the degree of symmetry of one of these magnetic fields leads to the fact that the armature (rotor or secondary element) makes a precise discrete movement. Result: The force moving the armature of a stepper induction motor is created as a result of the interaction of eddy currents in the armature with a rotating or traveling magnetic field. Stepper induction motors can rotate the rotor at a certain angle and discretely move flat or cylindrical electrically conductive armatures, which can be smooth and non-magnetic. A separate group of motors for a discrete electric drive is made up of two-coordinate linear stepping asynchronous machines, which also operate using the same counter-running magnetic fields both in the longitudinal and transverse directions. Conclusion: The features of the design of such electric machines are presented, the values of the magnetic induction in different zones of a two-coordinate stepper motor are determined, the relations for calculating the steps of the armature in both the longitudinal and transverse directions are given.

Elliptical trainers and steppers are proposed as useful exercise modalities in the rehabilitation of injured runners due to the reduced stress on muscles and joints when compared to running. This study compared the physiological responses to submaximal running (treadmill) with exercise on the elliptical trainer and stepper devices at three submaximal but identical workloads. Authors had 18 trained runners (male/female: N = 9/9, age: mean ± SD = 23 ± 3 years) complete randomized maximal oxygen consumption tests on all three modalities. Submaximal tests of 3 min were performed at 60%, 70%, and 80% of peak workload individually established for each modality. Breath-by-breath oxygen consumption, heart rate, fuel utilization, and energy expenditure were determined. The value of maximal oxygen consumption was not different between treadmill, elliptical, and stepper (49.3 ± 5.3, 48.0 ± 6.6, and 46.7 ± 6.2 ml·min−1·kg−1, respectively). Both physiological measures (oxygen consumption and heart rate) as well as carbohydrate and fat oxidation differed significantly between the different exercise intensities (60%, 70%, and 80%) but did not differ between the treadmill, elliptical trainer, and stepper. Therefore, the elliptical trainer and stepper are suitable substitutes for running during periods when a reduced running load is required, such as during rehabilitation from running-induced injury.

This paper describes the research, development and prototype of an electro-mechanic electrical discharge plotter system based on a three-axis Cartesian robot. The plotter can trace monochromatic arbitrary figures or alphanumeric characters on a given substrate such as paper without using any ink. A discharge probe delivering controlled electrical discharges is moved on the two-dimensional surface of the substrate using stepper motor-driven linear actuators to generate the arbitrary figures similar to CNC-based laser cutters and EDMs. The heat of the plasma evolved during the dielectric breakdown of ambient air during an electrical discharge or an arc has been used to create dark spots on the substrate by surface carburization. The discharge pulse duration, electrical parameters and the actuator movement are controlled by a microcontroller. The common printing systems currently available in the market give 300 to 600 DPI of resolution. However, the plotter prototype featured in this article plots with a resolution of 60 to 80 DPI which is enough to demonstrate. This technology can potentially eliminate the need for inks and toners which need frequent refilling. Every refilling invites considerable expenditure and significant environmental impact when their containing cartridges are discarded. This article only intends to put forward the possibility of such a printing technique and not propose the perfect alternative for existing printing systems.

Actuators that can generate controllable compliant output motion are suitable for robots that need to interact safely with humans or the environment. To obtain the accurate output torque required to control the compliant motion, existing robotic actuators use one or more sensors to measure the deformation of a stiff or compliant element between the actuator and the output. The complexity, reliability, and cost of sensors are the current challenges. Deformation-based sensing also suffers from limited bandwidth and stability range. This paper proposes a torque-sensorless control method of stepper motors to generate compliant motion. Stepper motors are used because of their low cost and reliability. They also have a much higher torque-to-weight ratio and torque-to-rotor-inertia ratio than other DC motors. Torque and impedance controllers based on stepper motor current feedback are developed. Torque-sensorless impedance, and gripping force control experiments are provided to show the advantages of the proposed method. It is expected that the new control method for stepper motors can offer a competitive alternative when cost, stability, or bandwidth of complaint actuators are the major concerns.

Writing is one of the most important modes of communication that is an essential element in our day to day life, but for some people it is an impossible task due to their disabilities. Drawing an image nowadays is done using various technologies. Computer Numerical Control (CNC) writing machine sketches picture controlled by a computer system. In this work a low-cost CNC based writing machine is designed and fabricated to ease the difficulties. To design this model three axis controlling unit is needed to control X, Y and Z axis position. X and Y axis can be controlled by two stepper motor and Z axis can be controlled by servo motor. The Dual axis writer helps in performing the writing task with the help of a 2-axis setup using lead screws and stepper motors. The stepper motor aids in accurate writing and designing of required shapes and letters. The objective is to design and fabricate a simplistic model of CNC writing machine and to reduce the cost of the machine.

The sun tracking became of high necessity for increasing the efficiency and reducing the cost of photovoltaic systems and solar concentrators. This system is used for maximizing the normal incident direct solar radiation on the surface of these devices. This is essential in solar water pumping for irrigation and power generation. In the present study, a new prototype sun tracker (heliostat) is designed, constructed and tested. This sun tracker tracks the sun on two axes and uses a real time control unit and hybrid stepper motors. The control unit uses a low cost microcontroller compared to the other controllers. The microcontroller provides a large number of input/output pins for controlling the hybrid stepper motors and the LCD screen. Also, its internal memory size and the processing power are high making it the most suitable device for solving solar energy equations in real time. The proposed sun tracker is seen to be simpler in operation and more reliable than the PLC, microprocessor and electro-optical controlled systems. Results show that this sun tracker has a good accuracy for tracking the sun and that the experimental data are closely fit the theoretical results. Hybrid stepper motors with their advantages and the control system are suitable for these applications. Thus, this sun tracker is also seen to be suitable for the photovoltaic panel used for solar pumping, power generation and the dish type solar concentrators.

In this paper, a qualification management problem arising in semiconductor wafer fabrication facilities (wafer fabs) is studied. The stepper machines, a common bottleneck in many wafer fabs, must be qualified to process lots of different families. A qualification time window is associated with each stepper and family. It can be reinitialized as needed and can be extended by on-time processing of lots from qualified families. Fast heuristic approaches, among them a Greedy Randomized Adaptive Search Procedure (GRASP), are proposed to solve large-sized problem instances using a small amount of computing time. The qualification decisions modeled by binary decision variables are made by heuristic procedures that exploit the problem structure while the real-valued quantities for each family and stepper are computed using linear programming. Computational experiments based on randomly generated problem instances are conducted. The results show that the proposed matheuristics are able to quickly provide high-quality solutions.

This study addresses the position-tracking problem for hybrid-type stepper motors in the rotational $d-q$ coordinate system. The proposed controller aims to govern position behavior with the desired low-pass filter from the reference (input) to the position (output). A perturbed form of machine dynamics is adopted to handle both parameter variations and load uncertainties and the control law has two main advantages. First, the real-time auto-tuner increases the closed-loop cut-off frequency during transient periods and restores it to its nominal value as it approaches the steady state. Second, disturbance observers improve the closed-loop robustness against high-frequency disturbances and ensure the offset-free property without additional integral actions. The experimental results validate the practical advantages from the proposed controller with a 10-W prototype stepper motor control system.

The paper describes the principle of operation of a reversible stepper lift with a jamming type of propulsion, the scheme of which is developed on the basis of an already existing model, and equilibrium equations are provided under the condition of its worst loading on a support.

Hybrid stepper motors, which convert the input pulse train into rotating angle increments by using an open-loop control strategy, are widely used in industrial applications. The bearing is a key and vulnerable component in stepper motors, and the bearing faults affect the positioning accuracy and output torque of motors. Order analysis is an effective method in bearing fault diagnosis under varying speed conditions. The rotating angle curve is necessary for order analysis, but angle or speed sensors are not installed on hybrid stepper motors. In this article, a method of estimating the rotating angle from motor current is proposed and applied to bearing fault diagnosis. First, a variational nonlinear chirp mode decomposition method is introduced to decompose the current signal and extract a dominant mode that has a strong correlation with motor rotation. Second, the rotating angle is calculated, and the synchronous vibration signal is resampled using the rotating angle curve. Finally, the bearing fault type is identified from the envelope order spectrum of the resampled signal. The proposed method can accurately diagnose bearing faults and has potential applications in condition monitoring of stepper motors.

To improve the accuracy of permanent magnet (PM) rotor position estimation for a hybrid stepper motor (HSM), the authors propose a sensorless control design based on the back electromagnetic force (back-EMF) caused by magnetic induction and harmonic rejection via an orthogonal third-order phase-locked loop (PLL 3 rd) and an integral harmonic filter (IHF). The accuracy of estimation is analysed considering PM rotor position estimation errors. The harmonics of the back-EMF signal are eliminated by the IHF before entering the PLL 3 rd, which synchronises and decreases position estimation error. This technique is a simple, reliable, and effective method for implementing sensorless control of an HSM. An industrial test-bench was used to implement the proposed scheme. The experimental results are presented to validate the effectiveness of the proposed estimation method.

Additive manufacturing (AM) is one of the emerging production methodologies transforming the industrial landscape. However, application of the technology in fluidic power transmission and actuation is still limited. AM pneumatic stepper motors have been previously introduced to the field of image-guided surgical robotics, where their disposability and customizability are considered a significant advantage over conventional manufacturing. However, intrinsic dimensional limitations of AM parts and their poor surface quality affect mechanical performance. In this letter, a novel design, PneuAct-II, is presented combining AM, subtractive machining, and off-the-shelf components to achieve higher mechanical performance and resolution. Moreover, a motor identification setup has been built to automatically measure different aspects of the PneuAct motors, including wear, friction, leakage, and stall behavior at various boundary conditions. The effects of input pressure, stepping frequency, signal-width, and external torque on the stall behavior of motors with different clearances are studied. A maximum torque of 0.39 N $\cdot$ m at an input pressure of 6.5 bar is achieved for a motor with a total volume of 90 cm $^3$ , and a clearance of 156 $\mu$ m. A nominal resolution of 2.25 $^{\circ }$ at full-pitch and 1.125 $^{\circ }$ at half-pitch is accomplished. Both resolution and mechanical performance (667 N $\cdot$ m/bar $\cdot$ m $^3$ ) outperform the state-of-the-art (240 N $\cdot$ m/bar $\cdot$ m $^3$ by PneuAct-I).

In this article, we present cost-effective techniques to assess UHF RFID performance for real world applications. This includes a positioner, based on stepper motors and braided fishing lines, which can position a tag in 3-D space. In combination with inventory meta data like RSSI and phase, we previously showed its use for a variety of measurements, e.g., the influence of tag-distance to materials and other tags. In this work, we extend its range of applications by the investigation of polarization sensitive ground reflections and as reference for tag localization estimations. For the measurements themselves, we use a commercial off-the-shelf R420 Impinj reader, which we control via LLRP commands, implemented in Python. Using a low-cost RTL-SDR, we observed the communication between reader and tag and found out that the tag is responding for lower powers than the reader was able to detect it.

This is an open access article under the CC BY-NC-ND license. This paper presents a low cost, two-wheels self-balancing robot for control education powered by stepper motors developed at the University of Seville. This design improves a previous model based on DC motors that has been used for the last five years in different courses in which students learn electronics, computer programming, modeling, control and signal processing by means of the construction and control of this robot. The new design improves the performance and reduces the total price of the device.

Laser cutter is a technology that uses a laser for cutting, boring and engraving the materials. The accuracy of laser cutter technology is high compared to other traditional technology. It is used in industrial manufacturing applications and also commercials purpose. Laser cutter works by directing the laser through optics and controlled by the control system by following a G-code of the pattern to be cut onto the material. In this project, a 20w laser, low weighted parts and simple mechanism is implemented to make a portable laser cutter. Also, a separate power controller is provided for laser and the stepper motors. Hence, accuracy is obtained by adjusting the power supply of laser. By using the LIGHT BURN software, the G-CODE is generated to navigate the laser head. The images and impression designs are imported to the software to generate the G-CODE and navigate the laser head. In this software, output power of the laser is also controlled. The materials like wood, fibers can be cut efficient in 20w laser.

The spectrophotometric method is widely used for the qualitative and quantitative analysis of substances, in the study of the structure and composition of various compounds. The article solved the actual problem of spectrophotometers measuring process automating. The structure of the spectrophotometer control unit based on the Arduino Uno hardware platform has been proposed, a stepper motor driver scheme, providing replacement of the manual rotation system of the spectrophotometer diffraction grating to a system using modern stepper motors has been developed. It made it possible to increase the measurement efficiency by reducing the measurement time and improving the metrological characteristics of the spectrophotometer (the limiting absolute error in setting the wavelength is reduced from ± 0.5 nm to ± 0.3 nm).

One of the parameters is the reference to the quality of the gear that is run out. Run out is the change in the location of the current element rotates against a fixed point on the axis of reference. The method used to check for errors swivel gear that is by turning the gears are checked with the master gear. Checker tool run out of gears using stepper motors as gear and readings players run out using LVDT sensors. Mechanical construction specifications that is thedistance between spindle capacity maximum 170 mm. Maximum run out that can be read by the LVDT sensor is 3.50 mm. The operating system uses an interface program that can be adapted to the gear to be checked. Inspection run out gear carried on a pair of straight gears are split into two parts with module 2, number of teeth 34. The examination was conductedat four different gear positions, tolerance RCE (radial composite error) allowed for automotive applications (ISO grade 8) is0.09 mm, where the measurement results obtained from the smallest RCE at position 3 (1A on z-1 and 1B on the z -19) at 0.10 mm so we can say that the measured gear can not be used for automotive applications because the measured RCE exceed permissible limits.