Positioning in agriculture today
Today's farm machinery use precision positioning systems mainly for navigation and mapping purposes. It offers farmers metre to centimetre-level accuracy and uses specialized algorithms and hardware built per existent agriculture manufacturing standards that always considers the existence of an operator in control of the machine.
"As machinery approaches full autonomy, safe positioning will be a necessity to function at a high rate of reliability and resiliency," says Tanner Whitmire, director of sales and support for agriculture at Hexagon | NovAtel. "While the ag industry is still defining safety levels for autonomous applications, traditional GNSS positioning—no matter how accurate—is not the same as certified safe positioning."
What is safe positioning?
The current positioning technology can be called task positioning, which offers positioning output precision advertised at the 95th percentile. A positioning output that achieves functional safety with integrity means ensuring the absence of unreasonable risks due to hazards caused by a malfunction in any of the solution’s sub-systems and components. This means all possible malfunctions and their associated risks are considered during the design stage. Every component of a system must be verified, validated and certified to these possibilities for users to be confident in its application.A functionally safe position provides the assurance in the vehicle's location to protect people, crops, infrastructure and equipment in off-road applications such as agriculture.
"Achieving safe positioning is the goal," says Whitmire. "To move to a fully autonomous solution, we must advance our solution by continuing to fuse additional sensors while providing the ability to create precise positioning algorithms that will increase the position output's safety rating and increase the availability of the position.”
NovAtel's advanced GNSS software positioning engine mathematically considers all possible errors in the positioning solution and outputs this data as the protection level.The maximum error the system can tolerate is called the alert limit. Highly and fully autonomous equipment needs these parameters above and beyond the traditional high precision positioning in order to achieve the functional safety required to operate autonomously, making the most of a farmer's field.
How do we solve challenging environments?
Sensor fusion takes and combines data from different sensors on farm equipment and provides information to increase the availability of the positioning used for the machine’s environment and movement. It reduces the uncertainty of using the data from each sensor individually. SPAN® technology from NovAtel represents the fusion of NovAtel's advanced precise positioning algorithms with sensors such as inertial sensors and other vehicle information to provide consistent positioning when satellite visibility is challenged or obstructed.Further sensor fusion advancement continues as we add sensor inputs like cameras, radars and other sensor data types.
What challenges are on the road to achieving safe positioning?
Implementing functional safety requirements into an open-loop system like GNSS positioning has additional challenges over the development of more traditional closed-loop safety systems.Increasing the functional safety to an acceptable level means you have to understand every possible fault and the interaction and effects it has on the system.
Functional safety in traditional electronic solutions are typically closed-loop systems with full control over how each component may fail or affect the overall functionality.With GNSS positioning systems, there isn’t the ability to control the satellite constellations or anything between the satellite and receiver, including up to 26,000 kilometres of material. However, NovAtel can continuously monitor the GNSS signals with a worldwide network of ground stations and provide this correction data in a feed to the receiver to obtain the appropriate level of functional safety. NovAtel's GNSS correction network will be a vital component to attaining the required functional safety for positioning solutions.
How is NovAtel helping achieve safe positioning in the agriculture industry?
Current systems do a great job of addressing today's agriculture needs—however, the farms of tomorrow demand more stringent positioning requirements to account for more wholly autonomous machines. While implementing safe positioning systems may seem like a faraway pipe dream, NovAtel is working on bringing the future into the present.
NovAtel continues to leverage its aviation and automotive industry experience on functional safety in positioning to advance the agriculture industry. Its corrections services, software positioning engine and precise positioning algorithms are always progressing to achieve the required functional safety in a positioning system, maintaining the robustness and high availability that are standard on all NovAtel products and services.
"Our goal is to accelerate integration for developers looking to bring safe autonomous solutions to the ag industry," saysWhitmire. "Our teams are constantly looking for ways to support our industry partners and help make their visions a reality."
NovAtel continues to drive advancement in the agriculture and off-road industries with the 2020 launch of positioning, autonomy and perception development kits to accelerate platform development and production for autonomous applications. These kits provide human identification, obstacle detection and enhanced environmental awareness in addition to our assured positioning solutions.
The kits include the SMART7 antenna and autonomous robotic capabilities through the NovAtel OEM7 driver powered by the Robot Operating System (ROS™). They also feature TerraStar® GNSS Correction Services, ALIGN® heading and relative positioning firmware and SPAN GNSS+INS technology.