Kevin Kochersberger

Virginia Tech | VT · Department of Mechanical Engineering

This paper discusses a collaborative air-ground team of autonomous vehicles for exploring and navigating outdoors within an unknown environment. A custom multi-rotor equipped with onboard downward facing stereo cameras flies over an unknown environment capturing imagery and reconstructing a height map of the ground surface online. Together with a s...

Current research in experimental robotics has had a focus on traditional, cost-based, navigation methods. These methods ascribe a value of utility for occupying certain locations in the environment. A path planning algorithm then uses this cost function to compute an optimal path relative to obstacle positions based on proximity, visibility, and wo...

Autonomous navigation to a specified waypoint is traditionally accomplished with a layered stack of global path planning and local motion planning modules that generate feasible and obstacle-free trajectories. While these modules can be modified to meet task-specific constraints and user preferences, current modification procedures require substant...

This paper discusses the results of a field experiment conducted at Savannah River National Laboratory to test the performance of several algorithms for the localization of radioactive materials. In this multirobot system, both an unmanned aerial vehicle, a custom hexacopter, and an unmanned ground vehicle (UGV), the ClearPath Jackal, equipped with...

Localization in a global map is critical to success in many autonomous robot missions. This is particularly challenging for multi-robot operations in unknown and adverse environments. Here, we are concerned with providing a small unmanned ground vehicle (UGV) the ability to localize itself within a 2.5D aerial map generated from imagery captured by...

Autonomously searching for hazardous radiation sources requires the ability of the aerial and ground systems to understand the scene they are scouting. In this paper, we present systems, algorithms, and experiments to perform radiation search using unmanned aerial vehicles (UAV) and unmanned ground vehicles (UGV) by employing semantic scene segment...

We present an approach to simultaneously perform semantic segmentation and prepositional phrase attachment resolution for captioned images. The motivation for this work comes from the fact that some ambiguities in language simply cannot be resolved without simultaneously reasoning about an associated image. If we consider the sentence "I shot an el...

Unmanned aircraft development has accelerated with recent technological improvements in sensing and communications, which has resulted in an “applications lag” for how these aircraft can best be utilized. The aircraft are becoming smaller, more maneuverable and have longer endurance to perform sensing and sampling missions, but operating them aggre...

An unmanned remote sensing and sampling system has been developed to aid first responders in urban disaster assessment and recovery. The system design is based on a 90 kg autonomous helicopter platform with interchangeable payloads ranging from radiation detection to tethered robot deployment. A typical response would begin with three-dimensional t...

The acquisition of synchronous EO imagery and gamma radiation data in aerial overflights of an unmanned aircraft can provide valuable spatial context for radioactive source mapping. Using image-based 3D reconstruction methods, a terrain map can be generated and used to reason about more likely radiation source locations. For instance, vehicles may...

Terrain mapping using an unmanned aircraft is valuable in many different applications, such as those involving urban infrastructure classification, search and rescue, and post-disaster mapping where existing maps are now meaningless. LiDAR scanners provide one way of generating 3-D maps, however these devices are generally heavier, more expensive,...

As rocks are transported along the conveyor belt of a quarry, the maximum dimension of the rocks exiting the crushers should not exceed a size threshold specific to each crusher. If the rocks are too large then they can pose a threat to equipment, and lead to a large cost in repair and loss of production. A 2D vision system is presented, which is c...

In the event of a disaster, first responders must rapidly gain situational awareness about the environment in order to plan effective response operations. Unmanned ground vehicles are well suited for this task but often require a strong communication link to a remote ground station to effectively relay information. When considering an obstacle-rich...

A novel morphing control surface design employing piezoelectric Macro Fiber Composite (MFC) actuators is compared to a servo-actuated system. The comprehensive comparison including aerodynamics, size, weight, power, bandwidth, and reliability has been extended to include flight test comparisons. Flight agility and control response of the morphing-a...

The goal of this research was to evaluate different configurations of morphing wings. The morphing system employed piezoelectric actuators called Macro-Fiber Composites (MFCs) bonded to a thin composite wing. The strain of the MFCs causes deformation and morphing of the entire wing planform. Simulations were performed to evaluate the different conf...

Natural disasters all too often place human lives and property at risk. Recovery efforts following a disaster can be slow and painstaking work, and potentially put responders in harm's way. A system which helps identify defects in critical building elements (e.g., concrete columns) before responders must enter a structure could save lives. In this...

Recent events have highlighted the need for unmanned remote sensing in dangerous areas, particularly where structures have collapsed or explosions have occurred, to limit hazards to first responders and increase their efficiency in planning response operations. In the case of the Fukushima nuclear reactor explosion, an unmanned helicopter capable o...

Natural disasters can compromise the structural integrity of buildings. Three dimensional post-disaster building models, created using image-based 3D reconstruction techniques, would help early responders assess the extent of the damage. Image-based 3D reconstructions are advantageous as they only require a camera and tens of pictures to create a 3...

A novel morphing control surface design employing piezoelectric Macro Fiber Composite (MFC) actuators is compared to a servo-actuated system. The comprehensive comparison including aerodynamics, size, weight, power, bandwidth, and reliability has revealed several observations. The conformal morphing airfoil geometry increases the lift-to-drag ratio...

Stereo imaging is typically performed using two cameras that have been calibrated to account for lens-induced distortion and pointing errors, resulting in rectified images that are processed to obtain distance information. The accuracy of a 3-D map obtained from stereopsis is closely tied to the calibration data, and so relative motion between the...

A surface actuated variable-camber morphing airfoil employing a type of piezoceramic composite actuator known as Macro-Fiber Composite is presented. The proposed airfoil employs two cascading active surfaces and a pair of optimized pinned boundary conditions. The optimized locations of pinned boundary conditions and the geometric features allow for...

The operator of a tele-operated ground robot requires vehicle navigation information that is frequently limited by the bandwidth of the communications link and the sensing equipment provided, and this can result in less than ideal situational awareness to the operator. Operators are therefore tasked to extract as much usable information from the se...

The use of unmanned systems in hazardous environments is becoming more prevalent as technology progresses. This paper presents the development of a combined unmanned aerial vehicle and ground robotic system being developed by the Unmanned Systems Lab at Virginia Tech that can be deployed in a post-detonation scenario. The purpose of the system is t...

The authors have explored the use of morphing control surfaces to replace traditional servo-actuated control surfaces in UAV applications. The morphing actuation is accomplished using Macro Fiber Composite (MFC) piezoelectric actuators in a bimorph configuration to deflect the aft section of a control surface cross section. The resulting camber cha...

This research employs solid-state actuators for delay of flow separation seen in airfoils at low Reynolds numbers. The flow control technique investigated here is aimed for a variable camber airfoil that employs two active surfaces and a single four-bar (box) mechanism as the internal structure. To reduce separation, periodic excitation to the flow...

In aircraft, weight reduction represents one of the principal design goals, and landing gear design is no exception. Accounting for 3 – 7% of an aircraft’s weight, the landing gear is essentially dead weight after takeoff, and so reducing this weight becomes a priority of aircraft design. In addition to keeping the weight low, fixed gear designs ca...

Aerial terrain mapping has been used for many years to monitor natural habitats and ecosystems, assist in urban planning, and monitor trends in land usage. Recent improvements in digital imaging, LiDAR, and synthetic aperture radar have facilitated the generation of 3-D terrain models for analysis in these applications. Unfortunately, these systems...

The purpose here is to enable peak-to-peak actuation of piezocomposite devices to perform shape control of structures, specifically bimorph variable-camber control surfaces on small aircraft. One of the major drawbacks in implementing control with piezocomposite actuation is its asymmetry in the positive and negative voltage directions. To remedy t...

The research presented here employs solid-state actuators for flow separation delay or for forced attachment of separated flow seen in airfoils at low Reynolds numbers. To reduce separation, periodic excitation to the flow around the leading edge of the airfoil is induced by Macro-Fiber Composite actuated clamped-free unimorph benders. An electrome...

This paper describes a procedure and algorithm for localizing a plume source using an Unmanned Aerial Vehicle. The procedure first uses a weather station and current ground conditions to develop an initial estimate of the plume source using the Lagrangian Stochastic model and current off-the-shelf WindTrax software. Once the initial estimate is obt...

A piezoceramic composite actuator known as Macro-Fiber Composite (MFC) is used for actuation in the design of a variable camber airfoil intended for a ducted fan aircraft. The study focuses on response characterization under aerodynamic loads for circular arc airfoils with variable pinned boundary conditions. A parametric study of fluid–structure i...

A novel, bi-directional variable camber airfoil design employing a type of piezoceramic composite actuator known as Macro-Fiber Composite (MFC) is presented. From a broader perspective, the study aims to understand the behavior of solid-state aerodynamic force generation in high dynamic pressure airflow. The novel airfoil employs two active surface...

Many environments are hazardous to humans, requiring the use of robotics for certain tasks. These tasks, including navigation, are often conducted using a vision system for robot tele-operation. This paper aims to assess the effectiveness of various vision systems, including: in-situ monovision, aerial monovision, combined monovision, and stereovis...

A type of piezoceramic composite actuator commonly known as Macro-Fiber-Composite (MFC) is used for actuation in a variable camber airfoil design. The study focuses on aerodynamic and kinematical modeling, and static response characterization under aerodynamic loads for three similar concepts. From a broader perspective, the study aims to understan...

This paper presents a system architecture and design for the operation of an unmanned VTOL aircraft in obstacle-rich environments beyond-line-of-sight. The use of a scanning LIDAR is shown to be effective in detecting obstacles, and when combined with a visual image, allows an operator to efficiently guide the aircraft in a tactical descent. Human...

*† ‡ § ** An experimental, theoretical and computational evaluation of a remotely piloted morphing wing aircraft using smart materials is presented. A type of piezoceramic composite actuator commonly known as Macro Fiber Composite is used for wing morphing. The MFC actuators were implemented on a swept wing, 0.76 m wingspan aircraft. The experiment...

*† ‡ § Applications of aerial surveillance include homeland security, law enforcement, environmental monitoring, and damage inspection after natural disasters. This paper discusses the use of unmanned aerial vehicles (UAV) as low cost and easy to operate solutions for aerial reconnaissance. Currently, the use of UAVs is limited by the cost of the s...

A reproduction of the Wright 1901 glider, built by The Wright Experience(TM) in Warrenton, Virginia, was wind-tunnel tested at the Langley Full Scale Tunnel through a range of conditions similar to those experienced in flight 100 years earlier. The testing included a range of dynamic pressures that encompassed the stall and maximum gliding speeds,...

A reproduction of the Wright 1902 Glider, built by The Wright Experience TM in Warrenton, Virginia, was wind tunnel tested at the Langley Full Scale Tunnel through a range of conditions similar to what was experienced 100 years ago. Angle of attack to stall at 20 o , and sideslip angles of 20 ± o were evaluated. Canard and warping deflections were...

Testing of a 1910 Wright Vertical Four aircraft engine (S/N 20) was completed at the Delphi Automotive Systems Technical Center in Rochester, NY to determine typical engine performance parameters. This engine powered a Wright Model B aircraft in numerous demonstration flights from 1911 - 1912, establishing many firsts in aviation including the carr...

In an ongoing effort to research and build reproduction aircraft of the Wright Brothers, the Wright Experience® in Warrenton, VA has constructed Wright bent end propellers that were used from 1905 1915. Performance of this propeller has been evaluated by a wind tunnel test on an airfoil section representing the 70% station, as well as a fall propel...

In an ongoing effort to research and build reproduction aircraft of the Wright Brothers, the Wright Experience® in Warrenton, VA has constructed Wright bent end propellers that were used from 1905 - 1915. Performance of this propeller has been evaluated by a wind tunnel test on an airfoil section representing the 70% station, as well as a full prop...

Recent advances in computer technologies have resulted in a significant paradigm shift within American industry in the engineering design process. Unfortunately, engineering education has not evolved similarly to take advantage of these new design and analysis tools within the curriculum. Thus, there is currently a significant disconnect between wh...

A modal parameter estimation technique is presented which uses FRF curve fitting and mobility measurements from off-resonance sine-dwell excitation. An FRF is first obtained at a structural point with amplitude for all modes of interest, and the global parameters of natural frequency and damping are found. Next, the off-resonance response (mobility...

The measurement of mobilities on a 2D structure, a flat plate, is described. LDVs measure velocity along the line of sight between the laser and the structure. Methods for the transformation of the line-of-sight velocity to an out-of-plane velocity are discussed and demonstrated. Calibration methods needed to obtain mobility measurements without an...

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1994. Vita. Abstract. Includes bibliographical references (leaves 180-184).