in Canopus Blog
Inertial Navigation Systems (INS) for Unmanned Vehicles
Invention of fossil fuel powered vehicles brought about a big shift in our lives. Faster and convenient transportation has improved productivity and has led to accelerated growth in every sector. Focus is now shifting from manned to unmanned transportation. Research has really picked up in the past few years and unmanned vehicles are being used for a variety of critical applications. As the technology evolves, unmanned vehicles are expected to be replacing human-driven vehicles.
Unmanned vehicles can be classified in three categories – UUV i.e. underwater unmanned vehicles, UGV i.e. unmanned ground vehicles and UAV i.e. unmanned aerial vehicles. Each of these vehicles have a wide range of applications in their respective domains. From underwater search and rescue, reconnaissance, to surveying and monitoring of crop health, the applications are too diverse.
Some commonly known applications for unmanned vehicles are,
UUWs: Finding missing objects under water, search operations, monitoring underwater mines and surveying of offshore assets etc.
UGVs: Driver-less cars, robots for reconnaissance, payload delivery and unmanned missions.
UAVs: Aerial monitoring and surveillance, aerial deliveries (drones), crop surveying, monitoring of assets like warehouses, pipelines, power transmission lines etc.
Since unmanned vehicles are controlled by autopilot i.e. without any human intervention, electronic navigation systems play a crucial role in guiding autopilot controller to ensure that they travel along the set or predefined travel path.
Why do unmanned vehicles need INS?
Why do unmanned vehicles need inertial navigation systems rather than only GNSS /GPS navigation? Though GNSS navigation is easily available and typically cheaper than INS, it has a lot of disadvantages.
- GNSS signal coverage is good in open sky conditions but easily deteriorates in urban areas, forest areas and under seas where signals are obscured by buildings, trees or water. In difficult weather conditions also GNSS signal strength and accuracy goes down significantly.
- Further, GPS signals are susceptible to intentional and unintentional jamming and interference. With the signal specifications freely available in public domain, civilian GPS signals may easily be spoofed, making them easy to access and interfere with.
- Autopilot controllers which use actuators, motors to control the vehicles require vehicle dynamics sampled at high 50-100 Hz rates whereas GPS update rates / output rates are slow and cannot be used for control applications.
Considering all the above disadvantages, it is quite clear that depending only on GNSS is not at all advisable for civilian, commercial as well as military applications.
Aeron Inertial Navigation Systems for unmanned vehicles
Aeron offers a wide range of indigenously developed inertial navigation systems designed for autonomous control and unmanned vehicle navigation applications. From small form factor to tactical grade systems, Aeron has COTS INS products which are equipped with high quality sensors and latest features.
Here are some of the differentiators of inertial navigation systems manufactured by Aeron
- Superior Performance at moderate cost
Aeron’s long term commitment to the development of inertial navigation technology puts us at a strategic position where we can manufacture and supply high quality INS systems at a very competitive price. Our inertial navigation systems meet global standards and performance criteria.
Aeron’s MEMS INS systems give best in class performance with position drifts as low as 16 meters/minute without any external aiding i.e. without GPS, airspeed or odometer. This MEMS performance is even better than some FOG based systems.
With Airspeed or Odometer aiding but without GPS signal availability, performance as good as 2% of distance travelled can be achieved. With GPS fix available, Aeron’s INS can give positional accuracy of 2.5m CEP in standalone mode and 1m CEP with SBAS.
- Suitable for a wide range of applications:
As the application changes, the expectations from the navigation system also change. For defense applications, accuracy and ruggedness is non-negotiable. UUV (underwater) applications require stringent levels of ingress protection while UAV applications require compact and light weight INS payload. UGV applications can afford greater size and weight but demand higher immunity to vibration and shock.
Aeron’s Canopus INS is suitable for UAV and UUV applications being compact, light in weight and rugged. Octantis version of INS, equipped with g-insensitive gyros is suitable for UGV and ground applications. A wide customer-base from diverse application areas is a testimony to the versatility of our inertial navigation systems.
- Ruggedized products:
Canopus and Octantis both INS-GPS product families qualify to MIL standards and can be used in tactical applications. The operating temperature range for all INS products is -40 to 85 °C and can survive 20g of shock. Custom versions with shock survivability up to 2000g are available on request.