Digital Tracking Controller Research Articles

Electromechanical Devices of Adaptive and Control-Tracking Systems

In the presented work, some characteristics of devices of adaptive and control-tracking control systems are considered. The characteristic features of angle sensors, methods of converting analog signals with high accuracy (for example, sine-cosine transformers) occupies a leading position among the development and research of tracking systems. The modern electronic element base opens up new possibilities - the creation of tracking digital angle converters (TDAC) using the principles of digital tracking and adaptive control in them. Stability, efficiency, load form determines the reliability, accuracy, economy, service life of electromechanical automation devices, test equipment, etc. Determining the characteristics, establishing analytical relationships between the initial data and output parameters is one of the stages of the algorithm for solving the problems of designing equipment parameters for monitoring and tracking control systems, which in turn contributes to the development of a mathematical model from a system of equations, the joint solution of which allows you to establish analytical relationships between the initial data and settings.

Fully-integrated switched-capacitor voltage boost converter with digital maximum power point tracking for low-voltage energy harvesting

This paper proposes a fully-integrated switched-capacitor voltage boost converter with a digital maximum power point tracking (MPPT) control circuit for low-voltage and low-power energy harvesting. The proposed digital MPPT control circuit converts the analog voltage information of a PV cell into digital values and extracts the maximum power regardless of the harvester conditions and load current. Measurement results demonstrated that our proposed circuit can track the maximum power point of a PV cell successfully. The maximum voltage conversion ratio of our circuit was 5.6. The proposed power management system generated a 2.58 V output voltage from a 0.46 V input voltage. The maximum power conversion efficiency was 63.6%.

Fully automated coal quality control using digital twin material tracking and statistical model predictive control for yield optimization during production of semi soft coking- and power station coal

The quality control of a two-stage coal washing process involves several complex components that need to be modelled accurately, to enable autonomous control of the process. The first objective is to develop a method to track the material through the washing process, while ensuring accurate washing prediction models are used. This was achieved through a digital twin model of the Grootegeluk 1 coal processing plant. The model is the amalgamation of manipulating and combining of data-sets from the plant historian, geological wash tables, and mining dispatch servers. This information is then used to control and set the processing medium densities of all 15 modules on the plant, 10 modules in the primary wash and 5 modules in the secondary wash. This controller has been successfully implemented and controlled the plant for 10 days.

Development of a generator for percussive ultrasonic drills used in asteroid exploration based on impedance characteristics analysis

Percussive ultrasonic drills participate in asteroid exploration missions. Since space environments are complex and working loads vary dramatically, it is necessary to design a drive that better matches the percussive ultrasonic drill to make it achieve high-speed drilling with low power consumption. Impedance characteristics under different load conditions and the load varying in one drilling cycle are investigated based on analyzing the working principle of the percussive ultrasonic drill. An ultrasonic drill driver with automatic scanning resonant frequency and digital phase-locked loop frequency tracking control is designed according to the load characteristics. Series capacitance impedance matching ultrasonic drills is experimentally studied. Vibration amplitude and impedance characteristics of the ultrasonic drill driven by the designed driver are measured to evaluate the frequency tracking ability and the impedance matching. Finally, ultrasonic drilling experiments are conducted in room, low, and high temperature environments to investigate the driving performance. Under room temperature and 5 N drilling pressure, the speed of ultrasonic drilling into soft sandstone is 52 mm/min, and the power consumption is less than 70 W. The experimental results indicate that the designed driver can drive the percussive ultrasonic drill to achieve stable and high-speed drilling with low power consumption and low drilling pressure.

COVID-19, Digital Tracking Control and Chinese Cosmotechnology

The COVID-19 pandemic has opened our eyes to numerous global problems that can only be solved on a global scale. Especially in light of the good performance of the Sinic region in containing and eliminating the coronavirus, the importance of intercultural dialogue between East and West became even more evident. In this context, this paper explores the role of digital technologies and the underlying ontology of digital objects in China as well as in the wider Sinic region. Indeed, the third millennium, which has just begun and will witness the accelerating trends of global warming and most likely the deepening of the gap between rich and poor, numerous wars, and new pandemics, will certainly be marked by the development of digital technologies. Therefore, the paper investigates the specific features of traditional Sinic perceptions of technology as such, as well as their ideational underpinnings, which certainly influence specific Sinic perceptions of digital objects. This will, I hope, provide us with a better understanding of the cultural conditionality of differences and commonalities in the global processes of digitalization and their ontological underpinnings, so that we can pay more attention to both the dangers and the opportunities that cross-cultural interactions in this area can offer us.

Digital tracking control of the boost converter: prediction-based digital redesign approach

Several continuous-time tracking controllers of the DC-to-DC boost converters had been addressed, but few literature touched the digital tracking control because that was a challenging theoretical problem which consists of nonlinear, non-minimum phase and saturated control. Given a continuous-time nonlinear boost converter with continuous tracking control, this paper proposes a new sampled-data feedback laws from the available analog counterpart via digital redesign such that the state trajectories of the sampled-data closed-loop systems close to the continuous-time one in the sense of state-matching. An existing boost converter circuit has been demonstrated to visualize the feasibility of the proposed methodology.

Analysis of COVID-19 spreading and prevention strategy in schools based on continuous infection model

After the COVID-19 epidemic leveled off in China, many provinces have started to resume schooling. Long-term contact between students and teachers in such a closed environment in schooling can increase the possibility of the outbreak. Although the school closure can effectively alleviate the epidemic, large-scale students’ isolation not only causes social panic but also brings huge social and economic burden, so before the emergence of school epidemics, one should select and adopt more scientific prevention and control measures. In this study, according to the virus excretion of COVID-19 patients in the disease period, the infectious capacity of patients is redefined. After introducing it into the traditional suspected-exposed-infected-removed (SEIR) model, a continuous infection model that is more consistent with the actual transmission of COVID-19 patients is proposed. Secondly, the effective distance between students is calculated through real contact data. Based on the analysis of the effective distance, three types of isolation area prevention and control measures are proposed and compared with the recently proposed digital contact tracking prevention and control measures. Simulating the spread of COVID-19 in schools through real student contact data and continuous infection models, in order to compare the preventions and control effects of various prevention and control measures in the school epidemic situation, and evaluating the social influence of measures by accumulating the number of quarantines when prevention and control measures are adopted, we find that the COVID-19 can lead the cases to happen on a larger scale in the continuous infection model than in the traditional SEIR model, and the prevention and control measures verified in the continuous infection model are more convincing. Using digital contact tracking prevention and control measures in schools can achieve similar results to those in closed schools with the smallest number of quarantines. The research in this paper can help schools choose appropriate prevention and control measures, and the proposed continuous infection model can help researchers more accurately simulate the spread of COVID-19.

Digital hydraulic single-link trajectory tracking control through flow-based control

Recent advancement in controllability of digital hydraulic is similar to the performance of a proportional/servo hydraulic system, and several studies show that digital hydraulic will be an alternative for proportional/servo hydraulic. In this paper, tip point tracking of a single-link arm is taken as the subject of the study. Here, the single-link arm is controlled by a digital hydraulic system, which is established with parallel-connected on/off valves. In order to attain stepwise flow control, the pulse code modulation technique is used. By referring to the previous work, the control signal for the trajectory tracking is calculated by taking account of cylinder chamber pressure and velocity. But in this study, the required volume flow rate for trajectory tracing is taken into account for generating control signal. This approach improves the performance of the digital hydraulic system at lower velocity tracking and also reduces the computational complexity. The analysis is conducted with the proposed algorithm for 4-bit and 5-bit digital flow control units and tip point response of single link is presented. The results show that the 5-bit system has significantly better performance than the 4-bit system. In addition, the analysis is conducted with different stroke lengths such as 200, 100 and 50 mm for studying the behaviour of the system at lower velocity tracking. Better controllability is achieved at lower velocity tracking, and the results obtained with the proposed algorithm have nearly 2% tracking error.

Unified Output Redefinition for Digital Tracking Control of Non-Minimum Phase Pulse-Width Modulated DC–DC Switched Converters

Unified Output Redefinition for Digital Tracking Control of Non-Minimum Phase Pulse-Width Modulated DC–DC Switched Converters

Design and implementation of a digital MPPT controller for a photovoltaic panel

This paper proposes a simplified design and hardware implementation of a digital maximum power point tracking (MPPT) controller for a photovoltaic (PV) panel using PIC microcontroller 16F877A embedded technology. The 3 most well-known algorithms, perturb & observe, hill-climbing, and incremental conductance, are considered and analyzed from a practical implementation point of view. The control board was developed using simple circuits and tested under resistive load conditions lower than the load of the maximum power point. The MPPT controller proved its effectiveness, providing maximum power to the load under changing weather conditions.

Altitude tracking controller design for a small unmanned aerial vehicle based on linear-quadratic-Gaussian-integral control

This paper presents the design procedure of a digital altitude tracking controller based on optimal control theory. The controller governs the longitudinal dynamics of a small-scale fixed-wing unmanned aerial vehicle (UAV) via an inner-outer loop control structure. In particular, the inner feedback loop maintains the aircraft's longitudinal stability and controls the climb rate (vertical velocity) while the outer-loop tracks the desired altitude through barometric altitude feedback. The inner-loop controller is designed based on the linear-quadratic-Gaussian-integral (LQGI) approach which necessitates the aircraft's longitudinal model to be expressed by a state-space representation. In this work, the model is obtained via a system identification technique called the observer/Kalman filter identification (OKID) method. Actual flight test data is collected and used in the system identification algorithm. On the other hand, the outer-loop controller simply features a proportional-gain control which eliminates the error between a reference altitude and the aircraft's altitude measured in real-time. The proposed altitude tracking controller is implemented on the National Cheng Kung University's Swallow UAV system and has been validated through a series of successful flight tests.

Trajectory Adaptive Zpet Controller Without Factorization of Zeros for Non-Minimum Phase System In Application to Real-Time Digital Tracking Control of Electro-Hydraulic Actuator

Abstract Electro-hydraulic actuators are very important tools for industrial processes because they provide linear movement, fast response and accurate positioning of heavy load. Recently, with the research and development of mathematics, control theory and basic theory of hydraulic, hydraulic control technology has been developed and has been widely used in many applications such as industrial automation and machining processes. Due to its applications, the highest performance of the electro-hydraulic actuators on position, motion or tracking is needed. Therefore, a suitable controller is required to improve the performance of the electro-hydraulic actuator. Most researchers have used advanced control approach to improve the motion or tracking control. Based on these problems, we had done a real-time digital tracking control studies on electro-hydraulic actuator using trajectory adaptive zero phase error tracking control (ZPETC) without factorization of zero polynomial algorithm. The control strategy uses a recursive least square parameters estimation that was done offline prior the actual control operation by taking advantage of the available known reference input. The experimental results obtained show significant tracking performance.

Non-Minimum Phase Model of Vertical Position Electro-Hydraulic Cylinder for Trajectory Zpetc

Abstract Hydraulic actuator has been widely used in industrial applications due to its fast response and capability of moving heavy load. The nonlinear properties of hydraulic cylinder had challenged researchers to design a suitable controller for position control, motion control and tracking control. Based on these problems, we had done a real-time digital tracking control studies on electro-hydraulic cylinder using trajectory zero phase error tracking control (ZPETC) without factorization of zeros polynomial algorithm. With the proposed strategy, the controller parameters are determined using comparing coefficients methods. The electro-hydraulic system mathematical model is approximated using system identification technique with non-minimum phase system being considered. The real-time experimental result will be compared with simulation result using a model from a real plant.

Improved digital tracking controller design for pilot-scale unmanned helicopter

In this paper, methods for improved design of digital tracking controller for a pilot-scale unmanned helicopter are considered. By discretizing the linearized helicopter model, the linear quadratic with integral (LQI) capability is investigated and applied in order to develop an efficient tracking system including a state-feedback plus integral action. The helicopter velocities are used to formulate a prescribed position reference tracking trajectory. When both process and measurement noises are present, a Kalman filter (KF) is combined with the LQI to form a linear quadratic Gaussian with integral (LQGI) tracking system. Simulation studies illuminate both the capability of the controller design and the accuracy of the estimator. Next, H 2, H ∞ and mixed H 2 / H ∞ controls are designed and the results between methods are produced and compared.

Teaching sampled‐data H∞ control theory using arm robot experiment system

AbstractThis paper explains how to use an arm robot experiment system to teach sampled‐data H∞ control theory. A design procedure is presented for a digital tracking control system for a continuous plant with structured uncertainties; the target is the positioning control of an arm robot. To guarantee the robust stability of the closed‐loop system and provide the desired closed‐loop performance, the design problem is first formulated as a sampled‐data H∞ control problem, and is then transformed into an equivalent discrete‐time H∞ control problem. Finally, linear matrix inequalities are used to obtain a reduced‐order output‐feedback controller and a static state‐feedback controller. In a course, the design procedure is explained and practice is provided through simulations and experiments. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

A SCALAR SIGN FUNCTION APPROACH TO DIGITAL CONTROL OF CONTINUOUS-TIME CHAOTIC SYSTEMS WITH STATE CONSTRAINTS

In this paper, a scalar sign function-based digital design methodology is presented to develop a digital tracking controller for the continuous-time chaotic systems with absolute value state constraints. A scalar sign function, which is the counterpart of the well-known matrix sign function, is utilized to approximately represent the absolute value state term by a rational function. As a result, the original state constrained nonsmooth nonlinear system becomes a smooth nonlinear system having rational nonlinear terms. Then, an optimal linearization technique is applied to the afore-mentioned nonlinear system for finding an optimal linearization model, which has the exact dynamics of the original nonlinear system at any operating point of interest with minimal modeling error in the vicinity of the operating point on the trajectory. To overcome the effect of modeling errors and to quickly track the desired reference signals, a high-gain optimal analog tracker is designed for the obtained linear model. For practical implementation of the high-gain analog tracker, the prediction-based digital redesign technique is utilized to obtain a low-gain digital tracker for digital control of the sampled-data nonlinear system with constrained states. Chua's chaotic circuits are used to demonstrate the effectiveness of the proposed approach.

A digital oscillation-amplitude stabilizer

The design of a stabilizer of the oscillation amplitude of a mechanical oscillator is described. The stabilizer is characterized by digital tracking control of the feedback-circuit gain. The value of the digital code directly proportional to the oscillator damping factor is directly read out with an automated system. The digital-feedback linearity simplifies the calibration—only one reference point is necessary.

1A2-G03 速度型サーボ機構を有する2台の宇宙ロボットの協調制御 : 転置一般化ヤコビ行列を用いた軌道追従制御法の適用

1A2-G03 速度型サーボ機構を有する2台の宇宙ロボットの協調制御 : 転置一般化ヤコビ行列を用いた軌道追従制御法の適用

Cooperative manipulation of a floating object by some space robots: application of a tracking control method using the transpose of the generalized Jacobian matrix

In future space missions, it is considered that many tasks will be achieved by cooperative motions of space robots. For free-floating space robots with manipulators, we have proposed a digital tracking control method using the transpose of the generalized Jacobian matrix (GJM). In this paper, the tracking control method using the transpose of the GJM is applied to cooperative manipulations of a floating object by space robots. Simulation results show the effectiveness of the control method.

2P2-A13 転置一般化ヤコビ行列を用いた宇宙ロボットの軌道追従型ディジタル制御実験(宇宙ロボティクス・メカトロニクス)

2P2-A13 転置一般化ヤコビ行列を用いた宇宙ロボットの軌道追従型ディジタル制御実験(宇宙ロボティクス・メカトロニクス)