Vikram Kapila

Brief Adaptive tracking control using synthesized velocity from attitude measurements

The attitude tracking control problem of uncertain rigid spacecraft without angular velocity measurements is addressed in this paper. The adaptive control law, which incorporates a velocity-generating filter from attitude measurements, is shown to ensure the asymptotic convergence of the attitude and angular velocity tracking errors despite unknown spacecraft inertia. Simulation results are presented to illustrate the theoretical results.

Output feedback control for spacecraft formation flying with coupled translation and attitude dynamics

In this paper, we address an output feedback tracking control problem for the coupled translation and attitude motion of a follower spacecraft relative to a loader spacecraft. It is assumed that the leader spacecraft is tracking a given desired translation and attitude motion trajectory and the translation and angular velocity measurements of the two spacecraft are not available for feedback. First, the mutually coupled translation and attitude motion dynamics of the follower spacecraft relative to a leader spacecraft are described. Next, a suitable high-pass filter is employed to estimate the follower spacecraft relative translation and angular velocities using measurements of its relative translational position and attitude orientation. Using a Lyapunov framework, a nonlinear output feedback control law is designed that ensures the semi-global asymptotic convergence of the follower spacecraft relative translation and attitude position tracking errors, despite the lack of translation and angular velocity measurements of the two spacecraft. Finally, an illustrative numerical simulation is presented to demonstrate the effectiveness of the proposed control design methodology.

Development of Mobile Interfaces to Interact with Automatic Control Experiments [Focus on Education]

As mobile devices begin to dominate the market and as laboratory equipment is increasingly connected to the Internet, there is an opportunity for laboratory instructors to recognize and respond to these changes by developing mobile apps for interacting with the equipment. Most reported incorporation of mobile devices thus far have been in virtual laboratories that use software to simulate experiments. Although such laboratories have the benefit of allowing students to learn from mistakes without damaging remote equipment, student learning can be limited by denying them access to real data from real equipment. The primary contribution of this article is to outline the development of several mobile apps for interacting with real physical test beds in an automatic control laboratory, both in the laboratory and remotely. Results are provided from a preliminary investigation of the usability and user experience associated with the applications, using students who would ultimately be the users of the applications when they are integrated into the curriculum. Implementation considerations such as the application development, wireless communication, hardware interfaces, and control are discussed. A microcontroller-based interface to the laboratory hardware provides a low-cost solution that can monitor, command, and control experiments via mobile devices.

Spacecraft formation flying near sun-earth L/sub 2/ Lagrange point: trajectory generation and adaptive output feedback control

In this paper, we present a trajectory generation and an adaptive, output feedback control design methodology to facilitate spacecraft formation flying near the Sun-Earth L/sub 2/ Lagrange point. Specifically, we create a spacecraft formation by placing a leader spacecraft on a desired Halo orbit and a follower spacecraft on a desired quasi-periodic orbit surrounding the Halo orbit. We develop the nonlinear dynamics of the follower spacecraft; relative to the leader spacecraft, wherein the leader spacecraft is assumed to be on a desired Halo orbit trajectory. In addition, we design a formation maintenance controller such that the follower spacecraft tracks a desired trajectory. Specifically, we design an adaptive, output feedback position tracking controller, which provides a filtered velocity measurement and an adaptive compensation for the unknown mass of the follower spacecraft. The proposed control law is simulated for the case of the leader and follower spacecraft pair and is shown to yield semi-global, asymptotic convergence of the relative position tracking errors.

Technological Developments in Education and Automation

Technological Developments in Education and Automation includes set of rigorously reviewed world-class manuscripts dealing with the increasing role of technology in daily lives including education and industrial automation Technological Developments in Education and Automation contains papers presented at the International Conference on Industrial Electronics, Technology & Automation and the International Conference on Engineering Education, Instructional Technology, Assessment, and E-learning which were part of the International Joint Conferences on Computer, Information and Systems Sciences and Engineering

Technological Developments in Networking, Education and Automation

Technological Developments in Networking, Education and Automation includes a set of rigorously reviewed world-class manuscripts addressing and detailing state-of-the-art research projects in the following areas: Computer Networks: Access Technologies, Medium Access Control, Network architectures and Equipment, Optical Networks and Switching, Telecommunication Technology, and Ultra Wideband Communications. Engineering Education and Online Learning: including development of courses and systems for engineering, technical and liberal studies programs; online laboratories; intelligent testing using fuzzy logic; taxonomy of e-courses; and evaluation of online courses. Pedagogy: including benchmarking; group-learning; active learning; teaching of multiple subjects together; ontology; and knowledge management. Instruction Technology: including internet textbooks; virtual reality labs, instructional design, virtual models, pedagogy-oriented markup languages; graphic design possibilities; open source classroom management software; automatic email response systems; tablet-pcs; personalization using web mining technology; intelligent digital chalkboards; virtual room concepts for cooperative scientific work; and network technologies, management, and architecture. Coding and Modulation: Modeling and Simulation, OFDM technology , Space-time Coding, Spread Spectrum and CDMA Systems. Wireless technologies: Bluetooth , Cellular Wireless Networks, Cordless Systems and Wireless Local Loop, HIPERLAN, IEEE 802.11, Mobile Network Layer, Mobile Transport Layer, and Spread Spectrum. Network Security and applications: Authentication Applications, Block Ciphers Design Principles, Block Ciphers Modes of Operation, Electronic Mail Security, Encryption & Message Confidentiality, Firewalls, IP Security, Key Cryptography & Message Authentication, and Web Security. Robotics, Control Systems and Automation: Distributed Control Systems, Automation, Expert Systems, Robotics, Factory Automation, Intelligent Control Systems, Man Machine Interaction, Manufacturing Information System, Motion Control, and Process Automation. Vision Systems: for human action sensing, face recognition, and image processing algorithms for smoothing of high speed motion. Electronics and Power Systems: Actuators, Electro-Mechanical Systems, High Frequency Converters, Industrial Electronics, Motors and Drives, Power Converters, Power Devices and Components, and Power Electronics.

Output feedback control for spacecraft with coupled translation and attitude dynamics

In this paper, we address a tracking control problem for a spacecraft with coupled translation and attitude motion, in, the absence of translation and angular velocity measurements. We begin by describing the mutually coupled translation and attitude dynamics of the spacecraft. Next, a suitable high-pass filter is employed to estimate the spacecraft translation and angular velocities using measurements of its translational position and attitude orientation. Using a Lyapunov framework, a nonlinear output feedback control law is designed that ensures the semi-global asymptotic convergence of the spacecraft translation and attitude position tracking errors, despite the lack of translation and angular velocity feedback.

Mixed-reality learning environments

Even as mobile devices have become increasingly powerful and popular among learners and instructors alike, research involving their comprehensive integration into educational laboratory activities remains largely unexplored. This paper discusses efforts to integrate vision-based measurement and control, augmented reality (AR), and multi-touch interaction on mobile devices in the development of Mixed-Reality Learning Environments (MRLE) that enhance interactions with laboratory test-beds for science and engineering education. A learner points her device at a laboratory test-bed fitted with visual markers while a mobile application supplies a live view of the experiment augmented with interactive media that aid in the visualization of concepts and promote learner engagement. As the learner manipulates the augmented media, her gestures are mapped to commands that alter the behavior of the test-bed on the fly. Running in the background of the mobile application are algorithms performing vision-based estimation and wireless control of the test-bed. In this way, the sensing, storage, computation, and communication (SSCC) capabilities of mobile devices are leveraged to relieve the need for laboratory-grade equipment, improving the cost-effectiveness and portability of platforms to conduct hands-on laboratories. We hypothesize that students using the MRLE platform demonstrate improvement in their knowledge of dynamic systems and control concepts and have generally favorable experiences using the platform. To validate the hypotheses concerning the educational effectiveness and user experience of the MRLEs, an evaluation was conducted with two classes of undergraduate students using an illustrative platform incorporating a tablet computer and motor test-bed to teach concepts of dynamic systems and control. Results of the evaluation validate the hypotheses. The benefits and drawbacks of the MRLEs observed throughout the study are discussed with respect to the traditional hands-on, virtual, and remote laboratory formats. Mobile devices and test-beds can be integrated according to a novel lab education paradigm.Vision-based measurement and control, AR, and touchscreen enhance lab interactions.The proposed paradigm can offer the benefits of hands-on, virtual, and remote labs.An implementation is developed using an iPad and a motor test-bed to teach control.Evaluation with students validates the implementations educational effectiveness.

Using Tablets in the Vision-based Control of a Ball and Beam Test-bed

Although the onboard cameras of smart devices have been used in the monitoring and teleoperation of physical systems such as robots, their use in the vision-based feedback control of such systems remains to be fully explored. In this paper, we discuss an approach to control a ball and beam test-bed using visual feedback from a smart device with its camera pointed at the test-bed. The computation of a homography between the frames of a live video and a reference image allows the smart device to accurately estimate the state of the test-bed while facing the test-bed from any perspective. Augmented reality is incorporated in the development of an interactive user interface on the smart device that allows users to command the position of the ball on the beam by tapping their fingers at the desired location on the touchscreen. Experiments using a tablet are performed to characterize the noise of vision-based measurements and to illustrate the performance of the closed-loop control system.

Mechatronics Mania at the Inaugural USA Science and Engineering Festival [Focus on Education]

As the need for science, technology, engineering, and mathematics (STEM) professionals grows in the United States, the interest of students in STEM disciplines continues to decline [1]–[3]. To foster excitement for STEM subjects among K–12 students, outreach and informal education programs often aim to infuse STEM fields with the energy typically reserved for activities such as sports competitions [4].