Tag - VN-200

VectorNav’s VN-200 Integrated into Precision Imaging Payload

VectorNav announced that its VN-200 GPS-aided inertial navigation system (INS) was selected for integration into Overwatch Imaging‘s TK-series precision imaging payload. The payload is for aerial smart mapping and automatic detection applications for UAVs (unmanned aerial vehicles) and manned aircraft.  

Soda straw effect

Traditional tactical imagery payloads, such as stabilized turret systems, feature electro-optical cameras with small field-of-view angles and high zoom capabilities. Such systems are ideal for tracking target objects from high altitudes; however, they suffer from the “soda straw effect”. When this system is zoomed in to see small targets, only a small area of ground is viewable. When the system is zoomed out to view large areas, smaller details are not visible to the user. As such, stabilized “soda straw” video systems struggle when the application calls for finding small objects in very large areas. They are not an ideal match for industrial inspections or wide-area land management surveys. Overwatch developed an imaging system with  greater image resolution and area coverage for low-altitude manned and unmanned aircraft. In addition, to deal with all the data, Overwatch developed automated image processing software to turn imagery into geospatial intelligence.  

TK-series camera systems

Overwatch Imaging’s TK-series camera systems are designed around a unique, nadir-pointing pitch, roll and yaw stabilized mount. The system features an imaging module that holds application specific sensors and optics. There's also an on-board mini-supercomputer and on-board storage for custom image processing algorithms. To cover large areas with high resolution, engineers developed a step-stare scanning camera motion feature. Compared to traditional mapping systems, this feature increased the per-pass data by 4x. Users can map 4x the amount of ground per pass, increase the resolution by 4x or a combination of both. To implement this advanced imaging technique Overwatch required an INS which could mount to the optical bench.  

INS integration

Mounting the INS directly to the optical bench provided a few advantages. The team no longer needed to rely on aircraft INS for data, it removed the requirement for encoders on the individual axes, and reduced the control system and electronics complexity. Additionally, it provided a smaller overall form factor (critical to small and medium-sized UAS). It was also critical that the INS provide low latency attitude data within 0.1° accuracy for pitch and roll in dynamic conditions. This created a faster workflow, lessened the load on the onboard processor for real-time image stitching and allowed for operation at larger standoff ranges. The engineers at Overwatch surveyed the market and down-selected several inertial products from a variety of suppliers. The focus was to identify a solution with the highest accuracy in the smallest form factor, for the best price. The VectorNav VN-200 Rugged GPS-aided INS out competed all competitive products in each of these categories.  

VN-200

The VN-200’s ability to output accurate position and attitude data at up to 400 Hz and high gyroscope angular rate range (±2000 °/s) allowed the TK-series to maintain accurate attitude estimates while performing the step-stare scanning motions. “VectorNav has an excellent reputation in the marketplace,” said Greg Davis, Founder of Overwatch Imaging. “When a review showed that the VN-200 surpassed other INS solutions in size, cost and performance our choice was clear.” The VN-200 plays a vital role in the TK-series payloads. It provides valuable data for platform stabilization, roll sweeping, step-stare functionality and accurate geolocation of target objects, setting the TK-series apart from its competition. In October 2016 Textron Systems announced the integration of Overwatch Imaging’s TK-7 Firewatch featuring the VN-200 into the Aerosonde Small UAS. The TK-7 Firewatch features multi-megapixel color focal plane array and co-boresighted infrared sensors that enable the system to automatically detect anomalies, such as hot-spots for wildfire mapping. This enables wildland fire crews and forest health managers to more effectively monitor large areas, providing critical analysis, reporting and rapid response capability. Overwatch Imaging’s TK-series is in use in a multitude of new applications -- from vegetation management and infrastructure inspection to target auto-detection and geolocation.  

Shop VectorNav's VN-200 and other sensors at Unmanned Systems Source.

VectorNav’s VN-200 aids in precision geo-pointing for miniature Epsilon series of gyro-stabilized gimbals

Octopus ISR Systems, a division of UAV Factory Ltd., announced the release of a new feature, "Precision Geo-Lock", for its miniature Epsilon series of gyro-stabilized gimbals. Precision Geo-Lock combines a state-of-the-art GPS-aided inertial navigation system (GPS/INS) with dedicated software algorithms and payload operator software. It provides the user with highly accurate target geo-location, range-to-target, as well as Geo-Lock functionality and moving map user interface.

Precision geo-location challenges

Equipping a miniature airborne gimbal with precision geo-location presents a multitude of challenges. First, the gimbal operates in a high vibration environment, high accelerations and extreme ranges in temperature. Also, unmanned aircraft often use miniature gyro-stabilized gimbals. Thus, small size and low power consumption are significant factors. “Traditionally, small gyro-stabilized gimbals use an external heading source to estimate the geo-location of the target,” stated UAV Factory CEO Konstantins Popiks. “Onboard the unmanned aircraft, the attitude data is usually supplied by an autopilot. The estimate accuracy is imprecise due to the nature of low-cost sensors used in miniature autopilots. Miniature autopilots simply do not need the precise heading data required by the gimbal. As a result, the heading error generates large geo-location errors and provides little to no use for the unmanned aircraft operator. Additional errors occur due to misalignment of the gimbal and autopilot; these are separate subsystems mounted in different locations on individual soft vibration mounts.” For the Geo-Lock feature to work, a highly accurate external GPS/INS  needed to be integrated into the system. “Today the state-of-the-art miniature gyro-stabilized gimbals have a narrow field of view of less than 1.3 degrees," said Popiks. "Therefore, pointing accuracy should be significantly better than 1.3° to prevent the target pointing location from going out of frame.”  

VectorNav VN-200

In order to guarantee the successful implementation of the Precision Geo-Lock feature, UAV Factory partnered with VectorNav Technologies. VectorNav develops and manufactures high performance inertial navigation systems using the latest in MEMS sensor and GPS/GNSS technology. “VectorNav’s VN-200 was the only product on the market that offered a high-level of performance but small enough form factor for direct integration into the optical bench of the gimbal” said Popiks. “When the product delivered that level of accuracy despite the high vibrations, accelerations and temperature fluctuations of our application the choice was obvious.” UAV Factory’s Precision Geo-Lock provides better than 0.3 degree accuracy and is ‘Plug-and-Play’. This allows the customer to install the Epsilon gimbal and get accurate results on any platform and in a high-vibration environment. Epsilon gyro-stabilized turrets will be available with VN-200 single GPS-based INS solution, as well as the VN-300 dual GPS-based INS. A single GPS/INS solution is suitable for dynamic platforms such as manned and unmanned aircraft. Dual GPS/INS is a necessity for platforms with low dynamics, such as aerostats, ships and helicopters. You can shop VectorNav's entire line of sensors at Unmanned Systems Source.