Including Motion Control Research Articles

Incremental Stability of Discrete-Time First-Order Projection Elements

In this paper, we present and analyze a class of discrete-time and sampled-data controllers named first-order projection elements (FOPEs). FOPEs form a class of hybrid controllers that have an underlying linear base dynamics, which are combined with a projection operator that ensures that the input-output (I/O) pair is contained in a well-designed sector. The I/O sector-constraint enables performance benefits in various application domains including motion control of high-precision machines. After the introduction of FOPEs, we focus on incremental stability analysis of these hybrid controllers. We show that the properties of the projection operator ensure incremental stability of the open-loop FOPE dynamics in case of an underlying linear dynamics that is exponentially stable. In this case, we compute tight bounds on the incremental gain. Under an appropriate small-gain condition, we show incremental input-to-state stability of the sampled-data interconnection of a FOPE with a continuous-time linear time-invariant plant. For the case of projected integrator dynamics, we provide a counterexample showing that incremental stability can be compromised. We provide additional, necessary and sufficient conditions under which FOPEs with integrator dynamics are incrementally asymptotically stable. Numerical simulations provide a practical example of the established incremental properties for the trajectories of a dynamical system coming from an industrial motion control application.

Autonomous Surveillance for an Indoor Security Robot

Conventional surveillance for a security robot suffers from severe limitations, perceptual aliasing (e.g., different places/objects can appear identical), occlusion (e.g., place/object appearance changes between visits), illumination changes, significant viewpoint changes, etc. This paper proposes an autonomous robotic system based on CNN (convolutional neural network) to perform visual perception and control tasks. The visual perception aims to identify all objects moving in the scene and to verify whether the target is an authorized person. The visual perception system includes a motion detection module, a tracking module, face detection, and a recognition module. The control system includes motion control and navigation (path planning and obstacle avoidance). The empirical validation includes the evaluation metrics, such as model speed, accuracy, precision, recall, ROC (receiver operating characteristic) curve, P-R (precision–recall) curve, F1-score for AlexNet, VggNet, and GoogLeNet, and RMSE (root-mean-square error) value of mapping errors. The experimental results showed that the average accuracy of VggNet under four different illumination changes is 0.95, and it has the best performance under all unstable factors among three CNN architectures. For the accuracy of building maps in real scenes, the mapping error is 0.222 m.

Management of Motion and Anatomical Variations in Charged Particle Therapy: Past, Present, and Into the Future.

The major aim of radiation therapy is to provide curative or palliative treatment to cancerous malignancies while minimizing damage to healthy tissues. Charged particle radiotherapy utilizing carbon ions or protons is uniquely suited for this task due to its ability to achieve highly conformal dose distributions around the tumor volume. For these treatment modalities, uncertainties in the localization of patient anatomy due to inter- and intra-fractional motion present a heightened risk of undesired dose delivery. A diverse range of mitigation strategies have been developed and clinically implemented in various disease sites to monitor and correct for patient motion, but much work remains. This review provides an overview of current clinical practices for inter and intra-fractional motion management in charged particle therapy, including motion control, current imaging and motion tracking modalities, as well as treatment planning and delivery techniques. We also cover progress to date on emerging technologies including particle-based radiography imaging, novel treatment delivery methods such as tumor tracking and FLASH, and artificial intelligence and discuss their potential impact towards improving or increasing the challenge of motion mitigation in charged particle therapy.

Retracted] Cascading Failure Dynamics against Intentional Attack for Interdependent Industrial Internet of Things

The emerging Industrial Internet of Things (IIoT) provides industries with an opportunity to collect, aggregate, and analyze data from sensors, including motion control, machine‐to‐machine communication, predictive maintenance, smart energy grid, big data analysis, and other smart connected medical systems. The physical systems and the cyber systems are organically integrated, forming an interdependent IIoT. This system provides us with enormous advantages, but at the same time, it also introduces the main safety challenges in the design and operation phase. To exploit the security threats of IIoT systems, in this paper, we propose a novel security‐by‐design approach for interdependent IIoT environments across two different levels, namely, theory modeling and runtime simulation. Our method theoretically analyzes the cascading failure dynamics of the intentional attack network. Simultaneously, we verified the theoretical results through simulations and gave the risk factors that affect the system’s security to mitigate potential security attack threats. Besides, we prove its applicability through comparative simulation experiments to study application environments that rely on IIoT, which shows that our method helps identify risk factors and mitigate IIoT attacks’ mechanism.

High‐Temperature Environmental Protection Metal Material 3D Printing Equipment Development and Process Research

At present, 3D printing technology is becoming more and more popular, but the traditional learning method has some limitations. The price of 3D printing equipment is expensive, and there are some security risks in the process of learning operation. This paper mainly introduces the development and process research of high‐temperature environmental protection metal 3D printing equipment and realizes the design of 3D printing equipment combined with virtual reality technology. In this paper, the whole system of 3D printing equipment is designed and built. The function of motion platform and substrate in mechanical system is analyzed, and the detailed structure design is carried out; the control principle of control system including motion control system and temperature control system is introduced in detail, and the corresponding design and construction work is carried out. In this paper, the pure tin wire with low melting point was used as the experimental material, and the mechanical properties and microstructure of the metal tin forming parts were analyzed. On the basis of tin formation experiment, metal deposition experiment and metal forming error experiment were carried out with H65 high melting copper wire as the raw material. The experimental results show that when the printing speed is 35/mm, the dimensional accuracy of the products is high; the microhardness of the printed tin is close to that of the original material, the surface hardness is 12.50HV0.05, and that of the copper alloy is 14.31HV0.05; the tensile strength of tin wire after melt deposition is slightly reduced after tensile test for the machined tin parts, the ultimate tensile strength of the first group of specimens is reduced by 1.58%, and that of the second group is reduced by 0.74%. This paper combines virtual reality technology with 3D printing technology and develops 3D printing equipment for high‐temperature environmental protection metal using virtual reality technology. The forming and printing performance of the device is analyzed theoretically and experimentally. The experimental results verify the feasibility of the system and the practicability of the device.

Remote and Automated Camera Control Technology

The basic approaches to remote control of the movie camera, including motion control, were explored. The technical advantages of using such technologies in advertising and feature film production are analyzed. The perspective directions of development for such technologies in the conditions of Ukrainian film production are shown.

Grape Drying Process Using Machine Vision Based on Multilayer Perceptron Networks

This paper proposed a grape drying machine using computer vision and Multi-layer Perceptron (MLP) method. Computer vision is for taking grapes’ image on conveyor, whereas MLP is for controlling grape drying machine and classifying its output. To evaluate the proposed, a kind of grapes are put on conveyor of the machine and their images are taken every two min. Some parameters of MLP to control the drying machine includes dried grape, temperature, grape area, motor position, and motion speed. Those parameters are to adjust an appropriate MLP’s output, including motion control and heater control. Two different temperatures are employed on the machine, including 60 and 75°C. The results showed that the grape could be dried with similar area 3800 pixel at the 770th min using temperature 60°C and at the 410th min using temperature 75°C. Comparing between them, the similar ratio could also be achieved at 0.64 with different time 360 min. Indeed, the temperature setting at 75°C resulted faster drying performance.

Monolithic Fabrication of NPN/SiNx Dual Membrane Cavity for Nanopore-based DNA Sensing.

Nanoscale preconfinement of DNA has been shown to reduce the variation of passage times through solid-state nanopores. Preconfinement has been previously achieved by forming a femtoliter-sized cavity capped with a highly porous layer of nanoporous silicon nitride (NPN). This cavity was formed by sealing a NPN nanofilter membrane against a substrate chip using water vapor delamination. Ultimately, this method of fabrication cannot keep a consistent spacing between the filter and solid-state nanopore due to thermal fluctuations and wrinkles in the membrane, nor can it be fabricated on thousands of individual devices reliably. To overcome these issues, we present a method to fabricate the femtoliter cavity monolithically, using a selective XeF2 etch to hollow out a polysilicon spacer sandwiched between silicon nitride layers. These monolithically fabricated cavities behave identically to their counterparts formed by vapor delamination, exhibiting similar translocation passage time variation reduction and folding suppression of DNA without requiring extensive manual assembly. The ability to form nanocavity sensors with nanometer-scale precision and to reliably manufacture them at scale using batch wafer processing techniques will find numerous applications, including motion control of polymers for single-molecule detection applications, filtering of dirty samples prior to nanopore detection, and simple fabrication of single-molecule nanobioreactors.

Active disturbance rejection control: some recent experimental and industrial case studies

This paper presents a summary of some recent experimental and industrial case studies of active disturbance rejection control (ADRC). ADRC is a novel disturbance estimation and rejection concept, leading to a new technology with a distinct advantage where, unlike most existing methods, disturbances, internal and external, are actively estimated and rejected. Applications of the new approach in solving industry-wide bench mark problems have led to a slew of innovative solutions. The scope of the applications shown in this paper includes motion control, robotic-enhanced limb rehabilitation trainings, fuel cell systems, and the two-mass-spring benchmark problem. Recent production line validation results obtained are also included.

Technology of Online Inspection in CNC Machine Tool

In this paper, an online inspection system is developed based on TDNC-H8 open CNC system. The system includes motion control, program management, the preservation and processing of the result and other functions. To check the rationality of inspection route, optimize and modify the inspection program, avoid accidental collision, online inspection simulation function is developed with Visual C++ programming tool and OpenGL graphics library.

Математична модель оптимального керування рухом електрорухомого складу на підставі вирішення рівнянь Гамільтона-Якобі-Беллмана

Optimal control is a powerful tool, which allows you to solve complex management tasks, including motion control of electric rolling stock on railways. The optimization problem is a common concern of management theory. It consideres the current factor as an abstract object, which seeks to maximize the expected benefits (or minimize losses) at some future period of time. A mathematical model of electric rolling stock control systems, based on the solution of Hamilton-Jacobi-Bellman equation using the method of dynamic programming and solution of the problem relating to the time coordinate has been developed in this paper. To reduce the volume of calculations it has been proposed to determine the optimal expert system in the direction relating to the movement time of electric rolling stock - reverse Bellman approach. It is assumed that the end point of electric rolling stock movement is known - the ultimate coordinate of movement and given time of movement, and the final velocity at this point is zero - which corresponds to the arrival of the train to the destination.

Gallium nitride based power switches for next generation of power conversion

Power conversion impacts all areas of electricity consumption, including motion control, lighting, air conditioning, and information technology. Si, the workhorse of the industry, has served well so far but reached its material limits. To keep up with the advancement of technologies enabling new conveniences, power conversion techniques need to go through significant transformation that calls for the next generation semiconductor for power switching. SiC and GaN, which have the potential to push the envelope beyond Si providing solutions for the entire range of power conversion at higher efficiencies and reduced form factors. GaN HEMTs have an added advantage over SiC MOSFETs owing to the high‐mobility electron channel formed at the AlGaN/GaN interface, which has been the basis of radio frequency amplifiers. GaN has enabled systems that can run with lesser cooling at frequencies at least ten times higher than current Si‐based systems, significantly reducing the form factor both electrically (passive components) and mechanically (heat sinks). The high current and voltage required for high power conversion application make the chip area in a lateral topology uneconomical and difficult to manufacture. Vertical GaN devices on bulk GaN substrates complete the portfolio of power switches required to address the power conversion market.

Lateral and Vertical Transistors Using the AlGaN/GaN Heterostructure

Power conversion losses are endemic in all areas of electricity consumption, including motion control, lighting, air conditioning, and information technology. Si, the workhorse of the industry, has reached its material limits. Increasingly, the lateral AlGaN/GaN HEMT based on gallium nitride (GaN-on-Si) is becoming the device of choice for medium power electronics as it enables high-power conversion efficiency and reduced form factor at attractive pricing for wide market penetration. The reduced form factor enabled by high-efficiency operation at high frequency further enables significant system price reduction because of savings in bulky extensive passive elements and heat sink costs. The high-power market, however, still remains unaddressed by lateral GaN devices. The current and voltage demand for high power conversion application makes the chip area in a lateral topology so large that it becomes more difficult to manufacture. Vertical GaN devices would play a big role alongside of silicon carbide (SiC) to address the high power conversion needs. In this paper, the development, performance, and status of lateral and vertical GaN devices are discussed.

Study on the Control System of Area-Contact Magnetorheological Finishing Machine

To achieve the goal of processing large diameter and ultra-smooth optical components, the control system of the area-contact magnetorheological finishing machine is introduced. The system includes motion control systems, structural adjustment systems, detection systems and alarm systems. PLC, the core of the system, is used to data collection, input and output control, process control and so on. The touch screen as the man-machine interface is simple and intuitive, easily to operate. This paper describes the algorithms of this control system and introduces the design of the hardware and software of the system. This control system have a stability performance, strong anti-interference ability. The result shows that the magnetorheological finishing machine could processφ300mm optical components the optical components, radius range of optical components is -∞≤R-30 or 30≤R≤∞, and the surface roughness less than 1nm.

Design and Application of New Testing Slots in the Tracking Control System

A test soil-bin is an effective device to test the whole or components of the agricultural machinery. A new computer control and test system featuring PLC control and PXI bus has been designed to control the whole soil bin system including motion control and correlative date processing. This paper introduces the software design as well as the hardware design of the electric control system and test system. The result of the present work implied that soil-bin testing platform can provide reliable data for agricultural machinery research, which has a significant effect on the agricultural machinery technology innovation and saving the cost of research and development.

Process Data Driven Based Process Equipment Automatic Control Technology

Process equipment is essential for product manufacturing, especially for complex products such as aircraft and rocket. In order to improve the motion precision and automation level of process equipment, a new approach is brought forward. A data driven based process equipment automatic control system is introduced to control process equipment automatically according to process data. Fig. 1 in the full paper gives the system’s architecture. Based on analysis of the relationship among manufacturing processes, process plan information and process equipment, process equipment automatic control oriented information model was established. In order to realize automatic control of process equipment, a process equipment automatic control and management framework was established. The key technologies including motion control and motion detecting are discussed in detail. At last, the technology was applied to the design and manufacturing of a horizontal rocket rivet fixture. The application results show that this technology could remarkably increase the efficiency and accuracy of the manufacturing process.

Blended PCL/PLGA scaffold fabrication using multi-head deposition system

Solid free-form fabrication (SFF) technologies can endow a great chance for regeneration of damaged tissues or organs in scaffold-based tissue engineering. In this study, a novel blended scaffold fabrication through multi-head deposition system (MHDS) for tissue engineering is introduced. Fabrication of 3D tissue scaffolds using MHDS required the combination of several technologies, including motion control, thermal control, pneumatic control, and CAD/CAM software. Blended 3D poly-caprolactone (PCL)/poly-lactic-co-glycolic acid (PLGA) scaffolds with a uniform pore size of 600 μm and a line width and height of 200 μm were well fabricated having a fully interconnected architecture and calculated porosity of about 69.6%. The compressive strength and modulus of the scaffold is each about 0.8 and 12.9 MPa, which is enough to maintain its architecture during in vitro cell experiments. Finally, the biocompatibility of fabricated 3D scaffold was demonstrated through the cell proliferation experiment. In the near future, blended PCL/PLGA scaffold will be a good option of scaffold for tissue engineering.

The optimization of hybrid scaffold fabrication process in precision deposition system using design of experiments

In recent tissue engineering field, it is being reported that the fabrication of three-dimensional (3D) scaffolds having high porous and controlled internal/external architectures can give potential contributions in cell adhesion, proliferation and differentiation. To fabricate these scaffolds, various rapid prototyping technologies are being applied to. The rapid prototyping technology has made it possible to fabricate solid free-form 3D microstructures in layer-by-layer process. In this research, we introduce the development of precision deposition system, which is one of rapid prototyping technologies, and the fabrication result of scaffold using design of experiments (DOE) to optimize the deposition process. The precision deposition system required the combination of several technologies, including motion control, thermal control, pneumatic control, and CAD/CAM software. Through the organization of experimental approach using DOE, the fabrication process of hybrid scaffold, which is composed of blended poly-caprolactone, poly-lactic-co-glycolic acid and tricalcium phosphate, is established to get a uniform line width, line height and porosity efficiently.

Fabrication of a SFF-based three-dimensional scaffold using a precision deposition system in tissue engineering

Recent developments in tissue-engineering techniques allow physicians to treat a range of previously untreatable conditions. In the development of such techniques, scaffolds with a controllable pore size and porosity have been manufactured using solid free-form fabrication methods to investigate cell interaction effects such as cell proliferation and differentiation. In this study, we describe the fabrication of scaffolds from two types of biodegradable materials using a precision deposition system that we developed. The precision deposition system uses technology that enables the manufacture of three-dimensional (3D) microstructures. The fabrication of 3D tissue-engineering scaffolds using the precision deposition system required the combination of several technologies, including motion control, thermal control, pneumatic control and CAD/CAM software. Through the fabrication and cell interaction analysis of two kinds of scaffolds using polycaprolactone and poly-lactic-co-glycolic acid, feasibility of application to the tissue engineering of the developed SFF-based precision deposition system is demonstrated.

Sensorless Control of Single Switch-Based Switched Reluctance Motor Drive Using Neural Network

Neural networks (NNs) have proven to be useful in approximating nonlinear systems and in many applications, including motion control. Hitherto, NNs advocated in switched reluctance motor (SRM) control have a large number of neurons in the hidden layer. This has impeded their real-time implementation with DSPs, particularly at high rotational speeds, because of the large number of operations required by the NN controller within a sampling interval. One of the ideal applications of NNs in SRM control is in rotor position estimation using only current and/or voltage signals. Elimination of rotor position sensors is practically mandatory for high-volume, high-speed, and low-cost applications of SRMs, for example, in home appliances such as in vacuum cleaners. In this paper, through simulation and analysis, it is demonstrated that a minimal NN configuration is attainable to implement rotor position estimation in SRM drives. The NN is trained and implemented on an inexpensive DSP microcontroller. NN training data, current, and flux linkage are obtained directly from the system during its operation. Furthermore, the chosen method is implemented on a single-switch-converter-driven SRM with two phases. This configuration of the motor drive is chosen because it is believed that this is the lowest cost variable speed machine system available. Experimental verification of this motor drive system is provided to demonstrate the viability of the proposed approach for the development of low-cost motor drives.