Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 11 of 11
Full-Text Articles in Automotive Engineering
Utilizing Ground-Based Lidar Measurements To Aid Autonomous Airdrop Systems, Martin Cacan, Edward Scheuermann, Michael Ward, Mark Costello, Nathan Slegers
Utilizing Ground-Based Lidar Measurements To Aid Autonomous Airdrop Systems, Martin Cacan, Edward Scheuermann, Michael Ward, Mark Costello, Nathan Slegers
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
Uncertainty in atmospheric winds represents one of the primary sources of landing error in airdrop systems. In this work, a ground-based LIDAR system samples the wind field at discrete points above the target and transmits real-time data to approaching autonomous airdrop systems. In simulation and experimentation, the inclusion of a light detection and ranging (LIDAR) system showed a maximum of 40% improvement over unaided autonomous airdrop systems. Wind information nearest ground level has the largest impact on improving accuracy.
Comment On "Three-Dimensional Ascent Trajectory Optimization For Stratospheric Airship Platforms In The Jet Stream", Nathan Slegers, Ainsmar X. Brown
Comment On "Three-Dimensional Ascent Trajectory Optimization For Stratospheric Airship Platforms In The Jet Stream", Nathan Slegers, Ainsmar X. Brown
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
No abstract provided.
Exploiting A Gsm Network For Precise Payload Delivery, Eugene A. Bourakov, Oleg A. Yakimenko, Nathan Slegers
Exploiting A Gsm Network For Precise Payload Delivery, Eugene A. Bourakov, Oleg A. Yakimenko, Nathan Slegers
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
This paper introduces the novel concept of using a GSM network for command of and communications with multiple aerial delivery systems. The research prototype of such a system, Snowflake-N, allows communicating with other network clients via a commercial Blackberry Curve 8310 handheld over a Bluetooth connection. A new architecture allows reassigning targets and sending other relevant commands (via web interface, by voice, data, or text messages) to an onboard autopilot, which is within a network reach, from any place in the world. Similarly, a current position of the descending system and target assignment can be viewed from any computer connected …
Development And Testing Of The Miniature Aerial Delivery System Snowflake, Oleg A. Yakimenko, Nathan Slegers, Robyn A. Tiaden
Development And Testing Of The Miniature Aerial Delivery System Snowflake, Oleg A. Yakimenko, Nathan Slegers, Robyn A. Tiaden
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
This paper discusses the current status of the development of the miniature aerial delivery system to be further employed in a variety of different research projects. It starts from the overall description of the system and proceeds with the discussion of the test results performed so far. Specifically, it addresses the effects of the changing ground winds on touchdown accuracy. The paper ends with conclusions and recommendations.
Optimal Control For Terminal Guidance Of Autonomous Parafoils, Nathan Slegers, Oleg A. Yakimenko
Optimal Control For Terminal Guidance Of Autonomous Parafoils, Nathan Slegers, Oleg A. Yakimenko
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
This paper deals with the development of guidance, navigation and control algorithms for a prototype of a miniature aerial delivery system capable of high-precision maneuvering and high touchdown accuracy. High accuracy enables use in precision troop resupply, sensor placement, urban warfare reconnaissance, and other similar operations. Specifically, this paper addresses the terminal phase, where uncertainties in winds cause most of the problems. The paper develops a six degree-of-freedom model to adequately address dynamics and kinematics of the prototype delivery system and then reduces it to a two degrees-of-freedom model to develop a model predictive control algorithm for reference trajectory tracking …
Use Of Variable Incidence Angle For Glide Slope Control Of Autonomous Parafoils, Nathan Slegers, Eric Beyer, Mark Costello
Use Of Variable Incidence Angle For Glide Slope Control Of Autonomous Parafoils, Nathan Slegers, Eric Beyer, Mark Costello
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
Strictly speaking, most autonomous parafoil and payload systems possess only lateral control, achieved by right and left parafoil brake deflection. An innovative technique to achieve direct longitudinal control through incidence angle changes is reported. Addition of this extra control channel requires simple rigging changes and an additional servoactuator. The ability of incidence angle to alter the glide slope of a parafoil and payload aircraft is demonstrated through a flight-test program with a microparafoil system. Results from the flight-test program are synthesized and integrated into a six degree-of-freedom simulation. The simulation model is subsequently used to assess the utility of glide …
Variable Structure Observer For Control Bias On Unmanned Air Vehicles, Nathan Slegers, Mark Costello
Variable Structure Observer For Control Bias On Unmanned Air Vehicles, Nathan Slegers, Mark Costello
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
No abstract provided.
Use Of Dynamic Incidence Angle For Glide Slope Control Of Autonomous Parafoils, Nathan Slegers, Eric Beyer, Mark Costello
Use Of Dynamic Incidence Angle For Glide Slope Control Of Autonomous Parafoils, Nathan Slegers, Eric Beyer, Mark Costello
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
Strickly speaking, most autonomous parafoil and payload aircraft possess only lateral control, achieved by right and left parafoil brake deflection. An innovative new technique to achieve direct longitudinal control through dynamic incidence angle changes is reported. Addition of this extra control channel requires simple rigging changes and an additional servo actuator. The ability of dynamic incidence angle to alter the glide slope of a parafoil and payload aircraft is demonstrated through a flight test program with a micro parafoil system. Results from the flight test program are synthesized and integrated into a 6 degree-of-freedom simulation. The simulation model is subsequently …
Nonlinear Model Predictive Control Technique For Unmanned Air Vehicles, Nathan Slegers, Jason Kyle, Mark Costello
Nonlinear Model Predictive Control Technique For Unmanned Air Vehicles, Nathan Slegers, Jason Kyle, Mark Costello
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
A nonlinear model predictive control strategy is developed and subsequently specialized to autonomous aircraft that can be adequately modeled with a rigid 6-degrees-of-freedom representation. Whereas the general air vehicle dynamic equations are nonlinear and nonaffine in control, a closed-form solution for the optimal control input is enabled by expanding both the output and control in a truncated Taylor series. The closed-form solution for control is relatively simple to calculate and well suited to the real time embedded computing environment. An interesting feature of this control law is that the number of Taylor series expansion terms can be used to indirectly …
Comparison Of Measured And Simulated Motion Of A Controllable Parafoil And Payload System, Nathan Slegers, Mark Costello
Comparison Of Measured And Simulated Motion Of A Controllable Parafoil And Payload System, Nathan Slegers, Mark Costello
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
For parafoil and payload aircraft, control is affected by changing the length of several rigging lines connected to the outboard side and rear of the parafoil leading to complex changes in the shape and orientation of the lifting surface. Flight mechanics of parafoil and payload aircraft most often employ a 6 or 9 DOF representation with the canopy modeled as a rigid body during flight. The effect of control inputs is idealized by the deflection of parafoil brakes on the left and right side of the parafoil. Using a small parafoil and payload aircraft, glide rates and turn performance were …
On The Use Of Rigging Angle And Canopy Tilt For Control Of A Parafoil And Payload System, Nathan Slegers, Mark Costello
On The Use Of Rigging Angle And Canopy Tilt For Control Of A Parafoil And Payload System, Nathan Slegers, Mark Costello
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
Controllable parafoil and payload aircraft are controlled with downward deflection of left and right parafoil brakes. Lateral control is obtained by differential deflection while longitudinal control is created by collective deflection of the left and right side parafoil brakes. The work reported considers an alternative method to control parafoil and payload air vehicles by tilting the parafoil canopy for lateral control and changing rigging angle for longitudinal control. Using a nonlinear 9 degree of freedom simulation model, it is shown that canopy tilt provides a powerful lateral control mechanism and rigging angle provides a viable longitudinal control mechanism.