Safe, dependable autonomous farm equipment operated by minimal personnel
Sabanto sought to create autonomous farm equipment that can be safely operated remotely and requires minimal personnel. This presented several key challenges:
- Navigational precision: The navigation system needs to be exceptionally accurate and able to maintain exact heading at very low speeds and often over bumpy terrain. Precise placement and movement of the tractor with regard to crop rows and field boundaries is critical. Failure to maintain precision can cause rows to be damaged, planted seedlings to be uprooted, fences or equipment damaged, which present high risks to farmers.
- Reliability: Autonomous machines often operate for extended periods, out of sight, during the night and in all types of weather conditions and landscapes. The navigation system must be accordingly robust to maintain consistent operation in extreme and variable conditions. A mission critical requirement of the navigation system is to maintain position accuracy in the event of degraded or disrupted satellite signals caused by trees or operating in valleys, for example.
- Simple system integration: Sabanto wanted the navigation system to easily integrate with their centralised monitoring and field mapping software platform. This meant acquiring position and heading data rapidly from the navigation system using a simple API solution that Sabanto uses to control tractor direction and speed, and when to actuate attached equipment, such as tillers and spray pumps.
GNSS Compass – the solution for all seasons
Sabanto selected the Advanced Navigation GNSS Compass as the navigational system of choice as it met all requirements of heading and position accuracy, toughness and simple implementation.
”Durability, dependability, dust and waterproofing were large parts of our choice due to the harsh environment we operate in. The [GNSS Compass] device required a single waterproofed cable for operation and never failed on us in the field.Craig RuppCEO, Sabanto
The dual-antennas of the GNSS Compass provide two points of GNSS reference. This enables more precise heading over single-antenna systems and is essential for precision farming, where the typical requirement is decimetre (10cm) accuracy. This degree of accuracy is beyond that of basic GNSS, which is generally accurate to within several metres. The GNSS Compass provides Real-Time Kinematic (RTK) positioning that can overcome GNSS position errors due to signal timing and satellite orbit deviation – tiny errors in space equate to large errors on earth. RTK connects to nearby ground base stations which provide real-time GNSS correction data that the GNSS Compass uses to achieve near centimetre accuracy.
The GNSS Compass also features an Inertial Navigation System (INS). The INS roll, pitch and heading data is intelligently fused with GNSS position data to filter the various inputs. The result of this is improved position and heading information. This is especially beneficial when traversing rough, uneven or non-level surfaces that may cause GNSS data alone to possibly be erratic. Equally important, the INS provides navigational redundancy that allows the system to function in the event of temporary GNSS signal disruption due to vegetation or terrain. This provides additional confidence that the system can maintain operation even during GNSS outages.
“The reliability of the GNSS Compass gave us the peace of mind required to operate fully autonomously” Craig says.
The data platforms available for the GNSS Compass, such as NMEA, and Ethernet interface enable third-parties like Sabanto to rapidly integrate and test their autonomous farming systems. This reduces R&D lead times and speeds up time to deployment. Craig goes on to say:
“Advanced Navigation’s open source drivers allowed us to get up and running very quickly.
“The GNSS Compass enabled us to operate multiple autonomous agricultural pieces of equipment in the field without issue. We were able to trust that our systems would safely stay within the field boundary outlined via our mapping software.”
A navigation system well suited to autonomous farming applications
Using the success of Sabanto as an example, the GNSS Compass represents a navigational solution for autonomous farming equipment that is capable of the required accuracy and reliability. Not only that, it can withstand the rutts and corrugations and extreme weather of extended field operation. The GNSS Compass platform is providing a solid foundation for Sabanto’s plans for expanding the adoption of autonomous farming technology.
Contemplating the future, Craig says “We plan on scaling up our usage of the GNSS Compass to support a multitude of units operating in different states across the country.”
The success of Sabanto’s autonomous tractor systems and the increasing adoption of the FaaS model across the US have resulted in them being awarded Best Up-and-Comer at the 2020 Chicago Innovation Awards.
The GNSS Compass is a low-cost all-in-one GNSS/INS navigation and heading solution. It provides accurate dual-antenna GPS-based heading that is not subject to magnetic interference and can maintain accurate heading during GNSS outages of up to 20 minutes. It features high accuracy RTK positioning and is plug and play with NMEA 0183, NMEA 2000, and Ethernet interfaces.