Double position sensitive detectors (PSDs) based measurement system of trajectory tracking of a moving target

2017 ◽  
Vol 34 (3) ◽  
pp. 781-799 ◽  
Author(s):  
Xiaohong Lu ◽  
Zhenyuan Jia ◽  
Xiaochen Hu ◽  
Wentao Wang

Purpose The purpose of this paper is to achieve the trajectory tracking measurement of a moving target based on double position sensitive detectors (PSDs). Design/methodology/approach In this paper, first, a double PSD-based measurement system including hardware system and software system is built up. Then, the working principle is studied to calculate parameters, and calibration experience is conducted. Finally, this double PSD-based measurement system is used to test angular displacement and axial displacement on the tool magazine and automatic tool changer. Findings In the experiment, the maximum position error of a space point based on double PSD measurement system is 0.8566 mm, and the average error is 0.4716 mm. These results show that the built double PSD-based measurement system of trajectory tracking of a moving target is reasonable. Originality/value Combining the characteristics of the PSD and principles of binocular visual measurement, a non-contact three-dimensional measuring system based on double PSDs is developed. The designed double-based measurement system is quite suitable for measurement of a fast-changing illuminant or in the case that the tracking accuracy is not tight.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bingjie Xu ◽  
Shuai Ji ◽  
Chengrui Zhang ◽  
Chao Chen ◽  
Hepeng Ni ◽  
...  

Purpose Trajectory tracking error of robotic manipulator has limited its applications in trajectory tracking control systems. This paper aims to improve the trajectory tracking accuracy of robotic manipulator, so a linear-extended-state-observer (LESO)-based prescribed performance controller is proposed. Design/methodology/approach A prescribed performance function with the convergence rate, maximum overshoot and steady-state error is derived for the output error transformation, whose stability can guarantee trajectory tracking accuracy of the original robotic system. A LESO is designed to estimate and eliminate the total disturbance, which neither requires a detailed system model nor a heavy computation load. The stability of the system is proved via the Lyapunov theory. Findings Comparative experimental results show that the proposed controller can achieve better trajectory tracking accuracy than proportional-integral-differential control and linear active disturbance rejection control. Originality/value In the LESO-based prescribed performance control (PPC), the LESO was incorporated into the PPC design, it solved the problem of stabilizing the complex transformed system and avoided the costly offline identification of dynamic model and estimated and eliminated the total disturbance in real-time with light computational burden. LESO-based PPC further improved control accuracy on the basis of linear-active-disturbance-rejection-control. The new proposed method can reduce the trajectory tracking error of the robotic manipulators effectively on the basis of simplicity and stability.


Author(s):  
Hong-Xin Cui ◽  
Ke Feng ◽  
Huan-Liang Li ◽  
Jin-Hua Han

Purpose To improve the trajectory tracking accuracy of 6R decoupled manipulator in singularity region, this paper aims to propose a singularity avoidance algorithm named “singularity separation plus improved Gaussian distribution damped reciprocal”. Design/methodology/approach The manipulator is divided into forearm and wrist, and the corresponding singularity factors are separated based on kinematics calculation. Singularity avoidance is achieved by replacing the common reciprocal with the improved Gaussian distribution damped reciprocal. Findings Compared with common damped reciprocal algorithm and classical Gaussian distribution algorithm, the continuity of the proposed algorithm is improved and the tracking error is minimized. The simulation and experiment results prove effectiveness and practicability of the proposed algorithm. Originality/value This study has an important significance to improve the efficiency and operation accuracy of 6R decoupled manipulator.


2018 ◽  
Vol 90 (8) ◽  
pp. 1249-1258 ◽  
Author(s):  
Piotr Grzybowski ◽  
Maciej Klimczuk ◽  
Pawel Rzucidlo

Purpose This paper aims to describe the idea behind and design of a miniaturized distributed measurement system based on a controller area network (CAN) data bus. Design/methodology/approach The intention of the designers was to build a light and modular measurement system which can be used in remotely piloted aircraft systems and ultra-light aircraft during flight tests, as well as normal operation. The structure of this distributed measurement system is based on a CAN data bus. The CAN aerospace standard has been applied to the software as well as the hardware comprising this system. PRP-W2 software designed for PCs is an additional component of the proposed measurement system. This software supports data acquisition from a recorder unit and allows for preliminary data analysis, as well as data conversion and presentation. Findings The system, complete with a high-speed data recorder, was successfully installed on board of an MP-02 Czajka aircraft. A research experiment using the system and oriented on airframe high frequency vibration analysis is presented in the final part of this paper. Research limitations/implications This measurement system allows analysis of high-frequency vibrations occurring at selected points of the aircraft. A data set is recorded by three-axis accelerometers and gyroscopes at frequencies up to 1 kHz. Practical implications The use of a miniature and lightweight modular measurement system will, in many cases, be faster and less expensive than full-scale measurement and data acquisition systems, which often require a lengthy assembly process. The implementation of this class of lightweight flight test systems has many advantages, in particular to the operation of small aircraft. Such solutions are likely to become increasingly common in unmanned aerial vehicles and in other light aircraft in the future. Originality/value The adaptation of a distributed measuring system with a high frequency of measurements for purposes of small and miniature aircraft.


Author(s):  
Jianfeng Li ◽  
Wenpei Fan ◽  
Mingjie Dong ◽  
Xi Rong

Purpose The purpose of this paper is to implement a passive compliance training strategy for our newly designed 2-UPS/RRR parallel ankle rehabilitation robot (PARR) to enhance its rehabilitation training safety. Design/methodology/approach First, a kinematic analysis of the PARR is introduced, and the mechanism ensures that the rotation centre of the ankle joint complex (AJC) coincides with robot’s rotation centre. Then, a passive compliance training strategy based on admittance control is described in detail and is implemented on our PARR. Findings Experiments involving healthy subjects were conducted, and the performance of trajectory tracking was quantitatively evaluated, with the results showing excellent compliance and trajectory tracking accuracy, which can ensure that a secondary injury to the AJC during passive rehabilitation training is avoided. The influence of different admittance parameters was also simulated and analysed, which can contribute to the development of adaptive parameter adjustment research. Originality/value The paper can be used to improve the effectiveness of ankle rehabilitation, to alleviate manual therapy problems in terms of labour intensiveness, precision and subjectivity and to ensure safety and comfort during rehabilitation sessions.


Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4852
Author(s):  
Grzegorz Bomba ◽  
Artur Ornat ◽  
Piotr Gierlak

The article discusses the quality testing of a measuring system consisting of a CNC machine with measuring probes. The research was conducted in a broader context regarding the implementation of the closed door technology, i.e., production without human intervention, in an aviation plant manufacturing aircraft gearbox systems. This technology may involve automated measuring operations performed in machining centers, and not in measuring laboratories, provided that the quality of the measurements is appropriate. The aim of the study was to investigate whether the CNC machining device can be used to measure the geometric features of aircraft gearbox housing. For this purpose, measurement experiments were carried out with the use of three different probes. Measurements were carried out using four sequences of increasing complexity, so that, after error analysis, it was possible to find the causes of possible irregularities. A reference ring with known dimensions and position in the working space of the machine was used for the measurements performed as part of the assessment of the measurement system. The quality of the measurements was evaluated with the use of repeatability and reproducibility testing and statistical process control. The analysis results showed that the tested measurement system ensures adequate accuracy and repeatability, and the measurement process is characterized with adequate efficiency in relation to the manufacturing tolerance of the components produced using the machine. Thus, it was proven that the measurement process can be carried out on a machining device, which enables its integration into the closed door technology.


1995 ◽  
Vol 377 ◽  
Author(s):  
R. Martins ◽  
G. Lavareda ◽  
F. Soares ◽  
E. Fortunato

ABSTRACTThe aim of this work is to provide the basis for the interpretation of the steady state lateral photoeffect observed in p-i-n a-Si:H ID Thin Film Position Sensitive Detectors (ID TFPSD). The experimental data recorded in ID TFPSD devices with different performances are compared with the predicted curves and the obtained correlation's discussed.


2015 ◽  
Vol 27 (3) ◽  
pp. 316-327 ◽  
Author(s):  
Daniel Jurburg ◽  
Elisabeth Viles ◽  
Carmen Jaca ◽  
Martin Tanco

Purpose – Continuous improvement (CI) is regarded as a powerful approach to achieve business excellence. However, the implementation is not simple as it involves managing a considerable amount of tangible and intangible factors throughout the whole organization. The purpose of this paper is to fill the gap by presenting first-hand information about how companies really implement and organize their CI processes. Design/methodology/approach – The study was based on semi-structured interviews in ten high performing companies in the Basque Country, a region in northern Spain well known for its business quality. The objective was to analyze the state of their CI processes, putting special focus on how the organizational structure integrates with the CI processes and what are the characteristics of the corresponding measurement system. Findings – The study shows a lack of company-wide focus on CI, little written evidence of previous improvement activities, unclear improvement process owner, and poor use of adequate measurement systems to monitor CI. Practical implications – Managers should understand that is not enough to guarantee their own commitment and provide the structure, since in order to become learning organization, a different holistic approach towards the CI process must be adopted. Originality/value – While most previous work on this field have focused primarily on how to implement different techniques in order to achieve better productive performance, this study presents empirical research from a more holistic approach, assessing the characteristics affecting CI by considering strategy, structure, and the measurement system.


Author(s):  
Bryan W. Schlake ◽  
Brian S. Daniel ◽  
Ron Voorheis

In pursuit of improved safety, Norfolk Southern Corp. (NS) has partnered with Amberg Technologies to explore the potential benefits of a laser-based measurement system for measuring over dimensional freight rail shipments. Shipments that do not fall within a standard geometric envelope, denoted as Plate B in the Association of American Railroads (AAR) Open Top Loading Rules [1], are considered to be over dimensional, or High-Wide Loads (HWLs). Extending beyond the limits of the Plate B diagram, these loads are not permitted in unrestricted interchange service. Instead, they must be measured both at points of origin and at interchange points. For US Class I Railroads, the de facto method for measuring HWLs requires mechanical personnel to either climb on the equipment or use a ladder and physically measure the overall height and width of the load. Using a tape measure, plumb line, and 6-foot level, car inspectors, or carmen, must often make multiple measurements to determine the height or width of a critical point on the load. The summation of these measurements can be subject to mathematical human error. In addition to the inherent limitations with regards to accuracy and efficiency, this method of measurement presents considerable safety challenges. The objective of the project was to develop a portable, cost-effective and accurate measurement system to improve the day-to-day operational process of measuring HWLs and reduce human exposure to railyard hazards. Norfolk Southern worked closely with Amberg Technologies to provide a clear overview of the current measuring methods, requirements, challenges and risks associated with HWLs. Amberg then developed a prototype system (with patent pending) and successful tests have been completed at both a point of origin for NS shipments and at a location where HWLs are received at interchange. The measuring system consists of a tripod mounted laser, a specially designed track reference target (TRT) and software designed specifically for HWL measurements. The system allows car inspectors to take measurements from a safe, strategic location away from the car. As a result, this system eliminates the need to climb on the equipment or a ladder and greatly reduces the amount of time spent on and around live tracks. In addition, initial tests indicate that this technology reduces the labor time required to measure HWLs by as much as one half while improving measurement accuracy. These tests have demonstrated that a laser-based system has the potential to greatly improve the safety, efficiency and accuracy associated with measuring HWLs.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Vieri Maestrini ◽  
Andrea Stefano Patrucco ◽  
Davide Luzzini ◽  
Federico Caniato ◽  
Paolo Maccarrone

PurposeGrounding on resource orchestration theory, this paper aims to study the relationship between the way buying companies use their supplier performance measurement systems and the performance improvements obtained from suppliers, with relationship trust identified as a mediator in the previous link.Design/methodology/approachThe authors design a conceptual model and test it through structural equation modelling on a final sample of 147 buyer-supplier responses, collected by means of a dyadic survey.FindingsResults suggest that the buyer company may achieve the most by balancing a diagnostic and interactive use of the measurement system, as they are both positively related to supplier performance improvement. Furthermore, relationship trust acts as a mediator in case of the interactive use, but not for the diagnostic. This type of use negatively affects relationship trust, due to its mechanistic use in the buyer-supplier relationship.Originality/valueThe authors’ results contribute to the current academic debate about supplier performance measurement system design and use by analyzing the impact of different supplier performance measurement system uses, and highlighting their relative impact on relationship trust and supplier performance improvement. From a methodological perspective, adopting a dyadic data collection process increases the robustness of the findings.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiaofeng Liu ◽  
Jiahong Xu ◽  
Yuhong Liu

Purpose The purpose of this research on the control of three-axis aero-dynamic pendulum with disturbance is to facilitate the applications of equipment with similar pendulum structure in intelligent manufacturing and robot. Design/methodology/approach The controller proposed in this paper is mainly implemented in the following ways. First, the kinematic model of the three-axis aero-dynamic pendulum is derived in state space form to construct the predictive model. Then, according to the predictive model and objective function, the control problem can be expressed a quadratic programming (QP) problem. The optimal solution of the QP problem at each sampling time is the value of control variable. Findings The trajectory tracking and point stability tests performed on the 3D space with different disturbances are validated and the results show the effectiveness of the proposed control strategy. Originality/value This paper proposes a nonlinear unstable three-axis aero-dynamic pendulum with less power devices. Meanwhile, the trajectory tracking and point stability problem of the pendulum system is investigated with the model predictive control strategy.


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