Stelios Ioannou

A Mobile Landing Platform for Miniature Vertical Take-Off and Landing Vehicles

Miniature vertical take-off and landing (VTOL) vehicles have limited range of operations mainly due to their limited payload capacities and power availability. To increase this range, a modified unmanned ground vehicle (UGV) is used to transport the VTOL to its target area serving as an on-site take-off/landing and possibly refueling base. A gimbaled landing platform design is proposed and the necessary equations are derived to level the platform despite of the pose (roll, pitch, yaw) of the UGV. To increase UGV endurance, a solar array is used and solar tracking capabilities for performance maximization are examined. Simulations are carried out to check the validity of the design. The case of an ATRV-Jr as the UGV base and a Raptor 90SE as the VTOL is investigated, but the design is generic enough and suitable for other UGV/VTOL vehicles

Improving Endurance and Range of a UGV with Gimballed Landing Platform for Launching Small Unmanned Helicopters

Design specifications for a high-endurance and range unmanned ground vehicle (UGV) with a gimballed landing platform on top of it for takeoff/landing, transporting to the target area and recharging of small/miniature unmanned helicopters are presented and justified. Specification constraints include UGV strict payload limitations, limited free space affecting power supply availability that impacts on-board available energy, limited endurance and operational range, as well as limitations and restrictions related to electric and non-electric small unmanned vertical takeoff and landing (VTOL) vehicles, similar to those of UGV with the most important being limited flying time. Focusing on the All Terrain Robot Vehicle (ATRV-Jr) UGV and a helicopter of the size of the Maxi Joker 2 as a testbed, a detailed analysis of component power consumption reveals reasons for reduced runtime and operational range. After a comparative study of state of the art power supply and battery technologies, a hybrid battery configuration is proposed that improves more than 500% the manufacturer-specified ATRV-Jr endurance (or 1,000% the currently used custom-made ATRV-Jr endurance) by considering: (1) optimum design with weight, volume, runtime and rechargeability being major restrictions and concerns, and (2) use of lower power sensors and processors without affecting UGV functionality and operability. A sun-tracking solar array that collects and stores energy is integrated with the UGV gimballed landing platform. Simulations demonstrate the validity of the design. Although the testbed is specific, the design itself is generic enough and suitable for other UGV/VTOL vehicles.

New MOV Failure Mode Identification Invention

This patent pending technology relates, generally, to surge protection devices. More particularly, it relates to a surge protection device that relies on the capacitive properties of the metal oxide varistor (MOV) as a part of an impedance network for failure identification. Unlike other designs that rely on thermal fusing to identify MOV operability, in this design the MOV is used as part of a capacitive network that would operate at a frequency other than 60 Hz. During normal operation (no failure), every capacitive impedance, including the MOV, will exhibit a voltage drop across them. On the other hand when the MOV fails as an open circuit then the current in this network will be zero and as a result zero voltage drops will be across the capacitive impedances. The reason only open circuit failure will be detected is because MOVs initially fail as a short circuit but eventually they fail as open circuit, due to continuous conduction .

Data Acquisition (DAQ) system dedicated for remote sensing applications on Unmanned Aerial Vehicles (UAV)

Continuous advances in unmanned aerial vehicles (UAV) and the increased complexity of their applications raise the demand for improved data acquisition systems (DAQ). These improvements may comprise low power consumption, low volume and weight, robustness, modularity and capability to interface with various sensors and peripherals while maintaining the high sampling rates and processing speeds. Such a system has been designed and developed and is currently integrated on the Autonomous Flying Platforms for Atmospheric and Earth Surface Observations (APAESO/NEA-YΠOΔOMH/NEKΠ/0308/09); however, it can be easily adapted to any UAV or any other mobile vehicle. The system consists of a single-board computer with a dual-core processor, rugged surface-mount memory and storage device, analog and digital input-output ports and many other peripherals that enhance its connectivity with various sensors, imagers and on-board devices. The system is powered by a high efficiency power supply board. Additional boards such as frame-grabbers, differential global positioning system (DGPS) satellite receivers, general packet radio service (3G-4G-GPRS) modems for communication redundancy have been interfaced to the core system and are used whenever there is a mission need. The onboard DAQ system can be preprogrammed for automatic data acquisition or it can be remotely operated during the flight from the ground control station (GCS) using a graphical user interface (GUI) which has been developed and will also be presented in this paper. The unique design of the GUI and the DAQ system enables the synchronized acquisition of a variety of scientific and UAV flight data in a single core location. The new DAQ system and the GUI have been successfully utilized in several scientific UAV missions. In conclusion, the novel DAQ system provides the UAV and the remote-sensing community with a new tool capable of reliably acquiring, processing, storing and transmitting data from any sensor integrated on an UAV.

On Improving Endurance of Unmanned Ground Vehicles: The ATRV-Jr Case Study

Unmanned ground vehicles (UGVs) have strict payload limitations, limited free space affecting power supply availability (number of batteries, size and volume) that impact onboard available energy resulting in limited endurance and operational range. This limitation is exacerbated by the addition of extra sensors and other related equipment needed for diverse applications. The ATRV-Jr UGV is considered as a testbed to identify causes of reduced runtime and operational range offering a detailed analysis of component power consumption. A comparative study between lead acid, lithium and fuel cell technologies allows for power supply enhancement via i) an optimum design with weight, volume, runtime and rechargeability being major restrictions and concerns, and, ii) the use of lower power sensors and processors without affecting vehicle functionality and operability

ERON: A PID controlled autonomous surface vessel

Aquatic unmanned robotic systems have gained popularity due to their abilities to perform a wide range of applications at low cost and no risk to human lives. This research investigates the development of the navigation system of “HPftN”, an Autonomous Surface Vehicle (ASV). The PID control system composed of 3 Arduino UNO boards, a GPS, a Compass and 4 thrusters can navigate the 2,86 meter long and 0,7 meters wide vessel, at speeds of 3-4m/s with an accuracy of less than one meter. Due to its flexible architecture, available onboard payload space, and powerful thrusters, this platform can easily accommodate the integration of various sensors and scientific equipment for a wide range of applications involving water sampling, temperature and salinity measurements to border patrol and monitoring, independent of weather conditions.

ERON: A flexible autonomous surface vessel

Aquatic unmanned robotic systems have gained popularity due to their abilities to perform a wide range of applications at low cost and no risk to human lives. This research investigates the development of the navigation system of “HPΩN”, an Autonomous Surface Vehicle (ASV). The PID control system composed of 3 Arduino UNO boards, a GPS, a Compass and 4 thrusters can navigate the 2,86 meter long and 0,7 meters wide vessel, at speeds of 3-4m/s with an accuracy of less than one meter. Due to its flexible architecture, available on-board payload space, and powerful thrusters, this platform can easily accommodate the integration of various sensors and scientific equipment for a wide range of applications involving water sampling, temperature and salinity measurements to border patrol and monitoring, independent of weather conditions.