Calvin Coopmans

Bio: Calvin Coopmans is an academic researcher from Utah State University. The author has contributed to research in topics: Evapotranspiration & Payload. The author has an hindex of 16, co-authored 74 publications receiving 896 citations.

A Physical experimental study of variable-order fractional integrator and differentiator

Abstract: Recent research results have shown that many complex physical phenomena can be better described using variable-order fractional differential equations. To understand the physical meaning of variable-order fractional calculus, and better know the application potentials of variable-order fractional operators in physical processes, an experimental study of temperature-dependent variable-order fractional integrator and differentiator is presented in this paper. The detailed introduction of analogue realization of variable-order fractional operator, and the influence of temperature to the order of fractional operator are presented in particular. Furthermore, the potential applications of variable-order fractional operators in PIλ(t)Dμ(t) controller and dynamic-order fractional systems are suggested.

A Survey and Categorization of Small Low-Cost Unmanned Aerial Vehicle System Identification

Abstract: Remote sensing has traditionally be done with satellites and manned aircraft. While these methods can yield useful scientific data, satellites and manned aircraft have limitations in data frequency, process time, and real time re-tasking. Small low-cost unmanned aerial vehicles (UAVs) can bridge the gap for personal remote sensing for scientific data. Precision aerial imagery and sensor data requires an accurate dynamics model of the vehicle for controller development. One method of developing a dynamics model is system identification (system ID). The purpose of this paper is to provide a survey and categorization of current methods and applications of system ID for small low-cost UAVs. This paper also provides background information on the process of system ID with in-depth discussion on practical implementation for UAVs. This survey divides the summaries of system ID research into five UAV groups: helicopter, fixed-wing, multirotor, flapping-wing, and lighter-than-air. The research literature is tabulated into five corresponding UAV groups for further research.

A comparative evaluation of low-cost IMUs for unmanned autonomous systems

Abstract: Inertial measurement units (IMUs) are widely used for navigation and calibration purposes on unmanned autonomous vehicles. This paper provides a comparative survey and evaluation of the low-cost IMUs focusing on both the possible sensor packages and the available software solutions. Several example IMUs are compared in detail including inertial only IMUs, GPS-coupled IMUs, and hobbyist-level IMUs. The future direction of low-cost IMUs are discussed including optical-flow-based solutions and collaborative IMUs.

Challenges in bridge inspection using small unmanned aerial systems: Results and lessons learned

Abstract: Unmanned Aerial Systems (UAS) have gained considerable private and commercial interest for a variety of jobs and entertainment in the past 10 years. This paper presents the applications of UAS in transportation and structural engineering with emphasis on bridge inspection. A brief but thorough review of UAS applications for State Department of Transportation in the United States is provided. Potential advantages of UAS are acknowledged and the major challenges of using them for bridge inspections are determined. The feasibility of UAS in crack detection, real-time and post-processing, is studied through a case study in controlled conditions. In addition, fatigue crack detection in steel bridges is investigated using three platforms with different mounted cameras. The results of these case studies showed the possibility of using UAS for damage detection in concrete and steel bridges with comparable results with human inspections in real-time. At its best, current technology limits UAS use to an assistive tool for the inspector to perform a bridge inspection faster, cheaper, and without traffic closure. The major challenges for UAS are satisfying restrictive FAA regulations, control issues in a GPS denied environment, pilot expenses and availability, time and cost allocated to tuning, maintenance, post-processing time and acceptance of the collected data by bridge owners. Using UAS, with self-navigation abilities and improving image- processing algorithms to provide results near real-time could provide bridge inspectors with a useful tool to reduce costs and improve inspection quality.

Analogue fractional-order generalized memristive devices

Abstract: Memristor is a new electrical element which has been predicted and described in 1971 by Leon O. Chua and for the first time realized by HP laboratory in 2008. Chua proved that memristor behavior could not be duplicated by any circuit built using only the other three elements (resistor, capacitor, inductor), which is why the memristor is truly fundamental. Memristor is a contraction of memory resistor, because that is exactly its function: to remember its history. The memristor is a two-terminal device whose resistance depends on the magnitude and polarity of the voltage applied to it and the length of time that voltage has been applied. The missing element—the memristor, with memristance M—provides a functional relation between charge and flux, dφ = Mdq. In this paper, for the first time, the concept of (integer-order) memristive systems is generalized to non-integer order case using fractional calculus. We also show that the memory effect of such devices can be also used for an analogue implementation of the fractional-order operator, namely fractional-order integral and fractional-order derivatives. This kind of operators are useful for realization of the fractional-order controllers. We present theoretical description of such implementation and we proposed the practical realization and did some experiments as well.Copyright © 2009 by ASME

Learning without Forgetting

Abstract: When building a unified vision system or gradually adding new capabilities to a system, the usual assumption is that training data for all tasks is always available. However, as the number of tasks grows, storing and retraining on such data becomes infeasible. A new problem arises where we add new capabilities to a Convolutional Neural Network (CNN), but the training data for its existing capabilities are unavailable. We propose our Learning without Forgetting method, which uses only new task data to train the network while preserving the original capabilities. Our method performs favorably compared to commonly used feature extraction and fine-tuning adaption techniques and performs similarly to multitask learning that uses original task data we assume unavailable. A more surprising observation is that Learning without Forgetting may be able to replace fine-tuning with similar old and new task datasets for improved new task performance.

Unmanned Aerial Vehicles: A Survey on Civil Applications and Key Research Challenges

Abstract: The use of unmanned aerial vehicles (UAVs) is growing rapidly across many civil application domains, including real-time monitoring, providing wireless coverage, remote sensing, search and rescue, delivery of goods, security and surveillance, precision agriculture, and civil infrastructure inspection. Smart UAVs are the next big revolution in the UAV technology promising to provide new opportunities in different applications, especially in civil infrastructure in terms of reduced risks and lower cost. Civil infrastructure is expected to dominate more than $45 Billion market value of UAV usage. In this paper, we present UAV civil applications and their challenges. We also discuss the current research trends and provide future insights for potential UAV uses. Furthermore, we present the key challenges for UAV civil applications, including charging challenges, collision avoidance and swarming challenges, and networking and security-related challenges. Based on our review of the recent literature, we discuss open research challenges and draw high-level insights on how these challenges might be approached.

Fractional order control - A tutorial

Abstract: Many real dynamic systems are better characterized using a non-integer order dynamic model based on fractional calculus or, differentiation or integration of non-integer order. Traditional calculus is based on integer order differentiation and integration. The concept of fractional calculus has tremendous potential to change the way we see, model, and control the nature around us. Denying fractional derivatives is like saying that zero, fractional, or irrational numbers do not exist. In this paper, we offer a tutorial on fractional calculus in controls. Basic definitions of fractional calculus, fractional order dynamic systems and controls are presented first. Then, fractional order PID controllers are introduced which may make fractional order controllers ubiquitous in industry. Additionally, several typical known fractional order controllers are introduced and commented. Numerical methods for simulating fractional order systems are given in detail so that a beginner can get started quickly. Discretization techniques for fractional order operators are introduced in some details too. Both digital and analog realization methods of fractional order operators are introduced. Finally, remarks on future research efforts in fractional order control are given.