Richard M. Kolacinski

Exploring Mars Using a Group of Tumbleweed Rovers

Current Mars exploration and science is limited to orbiters and areas close to original rover landing sites. Most of the places of geological interest lay many kilometers outside of suitable landing sites. In-situ resources such as wind can enable rovers to travel great distances on Mars while using little internal power. In this paper, a dynamic model of an individual wind driven rover is used to enhance a stochastic simulation of multiple rovers traversing the Martian environment. The results from this simulation support the claim that a group of rovers equipped with minimal control mechanisms or internal energy sources can autonomously disperse and explore Mars.

A novel biomimetic actuator system

The design of a biomimetic actuation system which independently modulates position and net stiffness is presented. The system is obtained by antagonistically pairing contractile devices capable of modulating their rate of geometric deformation relative to the rate of deformation of a passive elastic storage element in series with the devices input source. A mechanical model is developed and the properties of the device are investigated. The theoretical results developed are then compared with experimental evidence obtained from a simple prototype model of the system.

Design and mechanics of an antagonistic biomimetic actuator system

The design of a biomimetic actuation system which independently modulates position and net stiffness is presented. The system is obtained by antagonistically pairing contractile devices capable of modulating their rate of geometric deformation relative to the rate of deformation of a passive elastic storage element in series with the devices input source. A mechanical model is developed and the properties of the device are investigated. The local properties of the system are then investigated via Lyaponovs linearization method.

A mathematic framework for analysis of complex cyber-physical power systems

Developing technology and systems for future power systems requires an evolutionary approach where new “smart” grid technologies can be seamlessly integrated with the existing infrastructure and the ongoing overlay of new sensing and communication systems. As the diversity of these new technologies increases, the robust and secure operation of the grid will become dependent upon a detailed understanding of both physical and cyber components as well as their interactions. This paper focuses on the development of a mathematical framework and computational methodology that can be used to evaluate the stability and operational security of a complex cyber-physical power system in the context of stochastic hybrid dynamical systems, and proposes an approach based on embedding and symbolic dynamics that can be used to analyze complex system behaviors by encoding the system dynamics into symbol strings.

An information-theoretic architecture for advanced condition monitoring and control of power generating plants

This paper presents an enterprise architecture that supports the development and deployment of advanced control and condition monitoring algorithms in power generating plants. The architecture is based on information-theoretic concepts that are used to transform multi-modal data streams into actionable information.

Dynamic Simulations and Control of a Group of Wind Driven Martian Rovers [invited]

A group of wind driven rovers inspired by tumbleweeds can be used to explore vast regions of Mars. This paper predicts the mobility of tumbleweed rovers in a Mars rock field and presents effective mechanisms for the control of individual rovers and a rover group. Wind tunnel experiments were performed to determine the drag coefficients for several tumbleweed rover designs. A three-dimensional dynamic model was used to quantify tumbleweed obstacle navigation and control mechanisms. Results from the dynamic model were used as a physics anchor for a stochastic simulation of multiple tumbleweed rovers. The stochastic simulation uses a swarming algorithm to allow the rovers to disperse from a common location and systematically explore the surface of Mars.

Transient voltage stability of offshore wind farms following faults on the collector system

This work focuses on the analysis of the transient voltage stability at the point of interconnection (POI) of offshore wind farms following faults on the collector system. In particular, this study studies offshore wind farms that use an AC export system to transfer generated power onshore and investigates transient voltage stability under the influence of operating reactive power support equipment such as static VAR compensators (SVC) and active power support units such as battery storage or generation units at the POI. Operation of SVC and active power support such are widely believed to improve the stability and dynamic operation of offshore wind farms. This study, using the Great Lakes Offshore Wind Study models, determines the precise conditions under which SVC and active power support can improve the transient stability of the system following faults on the collector system.

Numerical Simulation of a Bouncing, Rolling and Sliding Tumbleweed Rover

In this paper, we investigate the numerical modeling of wind driven Martian Rovers whose physical design is based upon the Russian Thistle (Salsola Tragus). Specifically, several techniques for numerically modeling the imposition of nonholonomic and inequality constraints necessary for capturing the relevant dynamics of a tumbleweed-like wind driven rover are developed, implemented and evaluated for accuracy, precision and computational cost. Based upon the results of this study, a suite of modeling techniques that address simulation needs across the spectrum of fidelity and execution speed requirements is presented. Nomenclature t r = Position vector to the center of curvature of terrain t r = Radius of curvature of terrain tr ρ = Relative position vector from terrains center of curvature to center of tumbleweed rover r r = Position vector to the center of tumbleweed rover r r = Radius of tumbleweed rover m = Mass of the tumbleweed rover p I = Polar mass moment of inertia of the tumbleweed rover mars g = Acceleration due to gravity on Martian surface δ = Depth of contact c ρ = Position vector from center of tumbleweed rover to contact point between rover and terrain K F = The elastic restoring force rover K = Elastic modulus of tumbleweed rover f F = Friction force acting upon tumbleweed rover ω = Angular velocity of the tumbleweed rover rel v = Relative velocity between the contacting surfaces of the tumbleweed rover and the terrain s

Impact of wind turbine generator type in large-scale offshore wind farms on voltage regulation in distribution feeders

The goal of the U.S. Department of Energy (DOE) roadmap [1] is a 20% penetration of wind energy into the generation mix by 2030. Attaining this objective will help protect the environment and reduce fossil fuel dependency, thus improving energy security and independence. This paper discusses how the technology used in large scale offshore wind farms impacts voltage regulation in distribution feeders. Although the offshore wind farms are integrated into an interconnected power system through transmission lines, the system constraints can cause stability, resiliency and reliability issues. The major types of machine used in offshore wind farms are modeled using a generic model of General Electric (GE) wind machines. The transmission and distribution system models are based on the actual existing regional FirstEnergy/PJM power grid in Midwestern of United State. In addition, the impact of installing Static VAR Compensator (SVC) at Points of Interconnection (POI) on voltage regulation is investigated.

Discovering the intrinsic communication topology of systems using ants foraging behavior

Systems can be viewed as collections of interconnected elements that communicate with one another through physical phenomena. The principal focus of this work is the development of distributed algorithms for eliciting the intrinsic communication topology within a physical system and employ them for condition monitoring of the systems. The proposed approach in this paper provides the operators with graphs instead of tables or correlation matrices to identify the presence of a fault and request appropriate actions to mitigate it. Specifically, this paper considers physical systems and the available observations from a foraging perspective and discusses the application of ants foraging behavior techniques to discovery of the intrinsic communication topology of systems based on information-theoretic measures of information flow within systems. The mathematical framework of this approach and the application to an exemplary networked system are presented to illuminate discovery of the intrinsic communication topology.