Jack Langelaan

Jack Langelaan
Pennsylvania State University | Penn State · Department of Aerospace Engineering

Ph.D.

About

96
Publications
21,854
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1,719
Citations
Introduction
. Cooperative and collaborative transport of slung loads by autonomous rotorcraft . autonomous soaring flight . energy-optimal flight planning . planetary exploration by rotorcraft . autonomous ship-board landing using vision-based methods . state estimation

Publications

Publications (96)
Article
A method to estimate mass, center of mass, and moments of inertia of a multilift slung load is described. An analysis of system dynamics relates slung load response to cable tension, and a means to estimate cable tension without a direct cable force sensor is described. Three different estimators (least squares, maximum likelihood, and Kalman filte...
Article
Full-text available
A system for cooperative transport of a slung load by a team of autonomous rotorcraft is described. The method described here is hierarchical and centralized, with the payload defined as the leader (here denoted as load-leading control): the payload uses knowledge of its current state and its desired trajectory to determine the net force and moment...
Article
Full-text available
The performance of small uninhabited aerial systems (UAS) is very sensitive to the atmospheric state. Improving awareness of the environment and its impact on mission performance is important to enabling greater autonomy for small UAS. A modeling system is proposed that allows a small UAS to build a model of the atmospheric state using computationa...
Article
Improvements in solar cell weight and performance have enabled the development of small solar-powered aircraft that operate at low altitudes. Unlike high-altitude pseudosatellites, these aircraft must contend with significant stochastic variations in wind and solar energy. This paper examines speed scheduling for aircraft equipped with solar panels...
Conference Paper
View Video Presentation: https://doi.org/10.2514/6.2022-3279.vid Landings on ship decks in higher sea states pose significant challenges to UAV operators. This paper describes the development and testing of a self-contained vision-based autonomous deck landing system. A single monocular smart camera was used for detection and 6DOF pose estimation o...
Article
This paper studies a load-distribution-based trajectory planning and control strategy for a hierarchically controlled multilift system. It proposes a method that simultaneously plans payload trajectory and cable forces while satisfying path and force constraints and minimizing the difference in cable forces. A direct collocation method is used to s...
Preprint
Full-text available
Inverted landing is a challenging feat to perform in aerial robots, especially without external positioning. However, it is routinely performed by biological fliers such as bees, flies, and bats. Our previous observations of landing behaviors in flies suggest an open-loop causal relationship between their putative visual cues and the kinematics of...
Conference Paper
This paper studies a load distribution based trajectory planning and control strategy for a hierarchically-controlled multilift system. It proposes a method that simultaneously plans payload trajectory and cable forces while satisfying path and force constraints and minimizing the difference in cable forces. A direct collocation method is used to s...
Preprint
Full-text available
Landing upside down on a ceiling is challenging as it requires a flier to invert its body and land against the gravity, a process that demands a stringent spatiotemporal coordination of body translational and rotational motion. Although such an aerobatic feat is routinely performed by biological fliers such as flies, it is not yet achieved in aeria...
Article
Coaxial rotor configurations are common in multirotor unmanned aircraft systems (UAV) and are used in some manned helicopters. In the case of small-to-medium-sized unmanned rotorcraft, there is a lack of experimental data on icing and a lack of analysis of vehicle performance and flight characteristics in icing conditions. This paper (a) describes...
Article
Full-text available
The major post-Cassini knowledge gap concerning Saturn's icy moon Titan is in the composition of its diverse surface, and in particular how far its rich organics may have ascended up the "ladder of life." The NASA New Frontiers 4 solicitation sought mission concepts addressing Titan's habit-ability and methane cycle. A team led by the Johns Hopkins...
Preprint
Awareness and management of the risk of failing to encounter lift is fundamental to thermal soaring. When the weather changes or a thermal is missed the pilot may be exposed to a greater risk of landing out. In these situations the pilot may need to alter strategies in order to minimize risk exposure at the expense of speed, often referred to as "g...
Conference Paper
Full-text available
This paper addresses the problem of path planning and collision avoidance for multiple aerial vehicles. We develop an algorithm that is scalable, operates in real-time, and is implementable on a UAV's onboard computers. Our method makes use of velocity-based potential field methods for collision avoidance. Potential field methods utilize attractive...
Article
Autonomous soaring has the potential to greatly improve both the range and endurance of small robotic aircraft. This paper describes an autonomous soaring system that generates a dynamic map of lift sources (thermals) in the environment and uses this map for online flight planning and decision making. Components of the autonomy algorithm include th...
Article
The coupled dynamics and coordinated control of four rotorcraft carrying a single external payload is presented. A dynamic model and simulation environment is developed and analyzed. The uncontrolled system is shown to be inherently unstable and dynamically complex. A dynamic inversion controller is developed to stabilize the system and to follow f...
Article
Autonomous soaring has the potential to greatly improve both the range and endurance of small robotic aircraft. This paper describes the results of a test flight campaign to demonstrate an autonomous soaring system that generates a dynamic map of lift sources (thermals) in the environment and uses this map for on-line flight planning and decision m...
Chapter
This chapter discusses the generation of power and energy management (and harvesting) for unmanned aircraft. Implications for design as well as operation are discussed. Range and endurance for combustion-powered aircraft are compared with battery/electric aircraft; some design bounds for photovoltaic powered aircraft are described; and fuel cell po...
Article
This paper addresses the problem of safe flare to landing during autorotation, focusing on computing the region in the vehicle's state space from which a safe, feasible path to landing is guaranteed to exist. It (a) presents a method to compute safe, feasible trajectories for autorotation landing through wind shear and (b) uses this method to deter...
Article
This paper presents a trajectory parameterization method for calculating emergency flight paths with variable airspeeds under conditions of constant wind. The method is based on the Dubins curve; however, it has been modified to allow for acceleration along the path and finite rate of change in turn rate. The aircraft’s planar trajectory from an in...
Conference Paper
Sensor systems typically have not played a significant role in the aircraft conceptual design process. However, with the proliferation of unmanned aerial systems (UAS), the role of sensor systems on vehicle conceptual design can no longer be ignored. This issue is accentuated at smaller scales, where the sensing equipment may place significant cons...
Conference Paper
Full-text available
The formation dynamics and control of a four rotorcraft multi-lift system is presented. The uncontrolled system is shown to be inherently unstable and dynamically complex. A dynamic inversion controller is developed, and modified from a controller developed in previous work. The modified controller eliminates the need for sling cable forces feedbac...
Article
Soaring aircraft and birds utilize the energy of atmospheric convection to remain aloft. As this source of energy gains attention as a method for prolonging the flight times of small UAVs, it is necessary to evaluate the conditions under which it is a viable option. The indefinite endurance problem for soaring aircraft is cast in terms of a random...
Article
Object: Accurate edge tracing segmentation remains an incompletely solved problem in brain image analysis. The authors propose a novel algorithm using a particle filter to follow the boundary of the brain in the style often used in autonomous air and ground vehicle navigation. Their goals were to create a versatile tool to segment brain and fluid...
Conference Paper
Full-text available
This paper examines closed-loop dynamic soaring by small autonomous aircraft. Wind field estimation, trajectory planning, and path-following control are integrated into a system to enable dynamic soaring. The control architecture is described, performance of components of the architecture is assessed in Monte Carlo simulation, and the trajectory co...
Conference Paper
This paper describes a hierarchical approach to coordinated transportation of a slung load by a team of autonomous helicopters. A closed-loop controller computes net force and moments on the load's center of gravity so a desired trajectory is followed; cable forces at each attachment point are computed so that the net force and moment on the center...
Conference Paper
Coordinated soaring by a flock of small unmanned aerial vehicles (sUAVs) provides a means of conserving fuel while performing aerial tasks. The ability to exploit thermal columns in the atmospheric boundary layer allows sUAVs to remain airborne without expending any onboard sources of energy, i.e., soaring flight. This paper presents an analysis of...
Conference Paper
This paper introduces autonomous soaring methods that enhance the performance of small autonomous gliders in a thermal soaring environment. Thermal centering control is aided by an asymmetric Savitzky-Golay filter that computes estimates of total energy, rate of change of total energy and the second derivative of total energy using polynomial appro...
Conference Paper
A method for task assignment for persistent, low-altitude surveillance by a team of soaring-capable uninhabited air vehicles is discussed. The task assignment approach is based on minimizing the overall risk of mission failure (defined as failure to maintain continuous surveillance), where the risk to the mission of failure to perform a particular...
Conference Paper
Full-text available
This paper addresses the problem of path planning for a small UAV operating in a complex four dimensional (time and spatially varying) environment. A kinematic tree path planner that explicitly accounts for time is presented. This kinematic planner is shown to be resolution complete through comparison with the RC-RRT, and simulation results demonst...
Conference Paper
This paper presents a method to compute the set of steady state autorotation conditions from which safe flare to landing through can be performed. Equations of motion of a helicopter in autorotation through wind shear are presented; these equations are used to compute an optimal trajectory to landing from candidate initial states (distance and heig...
Article
The Green Flight Challenge occurred in September 2011 as a competition to spur extreme flight efficiency for general aviation aircraft. In order to compete, an aircraft had to demonstrate flight over a 200 mile course at an average groundspeed of 100 mph with a fuel efficiency greater than 200 passenger miles per equivalent gallon. This paper descr...
Conference Paper
This paper describes a method for ship deck estimation using only sensing carried aboard an autonomous rotorcraft: specifically, sensing is limited to a vision system, an inertial measurement unit and GPS. Using bearings to features on the ship deck and knowledge of helicopter state provided by the INS/GPS, a state estimator computes estimates of d...
Conference Paper
Dynamic soaring extracts energy from naturally occurring wind gradients that can be used to extend aircraft endurance, particularly in small UAVs. Autonomous thermal soaring has already been validated in flight tests with small UAVs, but this level of demonstration has not been performed for dynamic soaring UAVs, partly due to the precise wind meas...
Conference Paper
Full-text available
A method for distributed parameter estimation of a previously unknown wind field is described. The application is dynamic soaring for small unmanned air vehicles, which severely constrains available computing while simultaneously requiring updates that are fast compared with a typical dynamic soaring cycle. A polynomial parameterization of the wind...
Conference Paper
Full-text available
The objective of this work is to develop an autonomous autorotation landing system for an unmanned helicopter. Three-dimensional autorotation flight paths are obtained from a parametric optimization method (developed in previous work) to guide the aircraft through the three phases of a successful autorotation: entry, descent, and flare to landing a...
Conference Paper
This paper presents a method for navigation of a small unmanned aerial vehicle (UAV) through an unsurveyed static environment using a single forward pointing camera and a GPS corrected inertial measurement unit. The size and maneuverability of small UAVs allows for low altitude flights in complex environments. Without accurate estimates of obstacle...
Article
Full-text available
The paper presents the journey of the Pipistrers Taurus G4, the Worlds' first four-seat electric aeroplane and winner of the NASA Green Flight Challenge 2011, sponsored by Google, from idea to completion of competition. At the beginning, the race event and qualification requirements are presented. The selection of the aeroplane's configuration and...
Conference Paper
Full-text available
A method for trajectory optimization during the descent phase of helicopter autorotation is presented. The focus is on autonomous rotorcraft, although the approach could be extended to manned vehicles or used for pilot cueing. The approach is based on a Dubin's curve that has been modified to allow for acceleration and vertical translation along th...
Article
To enable long-distance, long-duration flights by small soaring-capable uninhabited aircraft, a graph-based method for planning energy-efficient trajectories over a set of waypoints is presented. It introduces the energy map, which is an upper bound on the minimum energy required to reach a goal from anywhere in the environment while accounting for...
Article
Full-text available
This paper describes a method for estimating wind field (wind velocity, rate of change of wind velocity and wind gradient) for small and mini unmanned aerial vehicles. The approach utilizes sensors which are already part of a standard autopilot sensor suite (GPS, inertial measurement unit, airspeed, magnetometer). The primary motivation is enabling...
Article
Full-text available
A method for navigation of a small unmanned rotorcraft through an unsurveyed environment using a combination of global positioning system/inertial navigation system (GPS/INS) and a monocular vision system is presented. The environment contains a mix of small, convex obstacles such as tree trunks and large, nonconvex obstacles typical of an urban ar...
Conference Paper
Full-text available
To enable coordinated soaring by a flock of small unmanned air vehicles a method for distributed mapping of the wind field is presented. Presently the work focuses on mapping convective activity (i.e. thermals). The map first discretizes the environment into cells and then uses a Kalman filter to estimate the vertical wind speed and associated cova...
Conference Paper
Full-text available
This paper presents a method for navigation of a small unmanned rotor craft through an unsurveyed environment using a single camera and an inertial measurement unit corrected by GPS. Current missions for small unmanned aerial vehicles involve low altitude flights in complex environments (e.g. urban canyons and forests) in close proximity to obstacl...
Conference Paper
Full-text available
This paper discusses energy harvesting by small Uninhabited Aerial Vehicles (UAV s). A receding horizon controller which computes a sequence of pitch rate commands with the goal of maximizing energy gain over a fixed horizon is derived. An energy based reward function is used to maximize energy gain with only local knowledge of atmospheric wind con...
Conference Paper
Full-text available
This paper presents an approach to planning long distance autonomous soaring trajec-tories for small uninhabited aerial vehicles harvesting energy from the atmosphere. An A* algorithm is used with a cost function which is the weighted sum of energy required and distance to goal. The effect of varying the weight parameter on the flight paths is expl...
Article
Full-text available
This paper presents an approach to near-optimal target localization for small and micro unmanned aerial vehicles using a family of precomputed parameterized trajectories. These trajectories are precomputed for a set of nominal target locations uniformly distributed over the sensor field of view and stored offline in a nondimensionalized form. Traje...
Conference Paper
Full-text available
This work develops an algorithm to initialize an Unscented Kalman Filter using a Particle Filter for applications with initial non-Gaussian probability density functions. The method is applied to estimating the position of a road vehicle along a one-mile test track and 7 kilometer span of a highway using terrain-based localization where the pitch r...
Article
This paper presents a methodology to compute the backwards reachable set from safe on ground to a trimmed autorotation condition. This backwards reachable set represents the region of the trimmed autorotation state space from which safe paths to touchdown at a specified point are guaranteed to exist. The backwards reachable set is found by computin...
Conference Paper
This paper compares the performance of histogram and particle filters for localizing and tracking a highly maneuvering target using two widely spaced horizontal passive sonar arrays. Both filters are numerical implementations of Bayes' filter, which use recursively estimate state vectors with nonlinear update equations and non-Gaussian prior probab...
Article
Improved sensing and planning for enhanced fl ight duration allow unpiloted small aircraft to fl y autonomously in cluttered environments over long distances.
Conference Paper
Full-text available
This work develops an algorithm to initialize an Unscented Kalman Filter using a Particle Filter for applications with initial non-Gaussian probability density functions. The method is applied to estimating the position of a road vehicle along a one-mile test track using terrain-based localization where the pitch response of the vehicle is compared...
Conference Paper
This paper presents a method for planning trajectories which exploit atmospheric energy to enable long distance, long duration flights by small and micro unmanned aerial vehicles. It introduces the energy map, which computes the minimum total energy required to reach the goal from an arbitrary starting point while accounting for the effect of arbit...
Article
Full-text available
This paper discusses energy extraction from atmospheric turbulence by small- and micro- uninhabited aerial vehicles. A nonlinear longitudinal dynamic model of a glider with elevators as the sole control input is used for the aircraft and feedback control laws for energy extraction are discussed. Using current measurements of wind speed and gra- die...
Conference Paper
Full-text available
This paper discusses energy extraction from atmospheric turbulence by small- and micro- uninhabited aerial vehicles. A controller which superimposes a gust-dependent control input on a state-feedback derived control input is proposed, and a genetic algo- rithm is used to obtain control gains as well as the optimal nominal trim state is described. C...