Welcome to Zupt Autonomous Products and Technology Introduction to Commercial Autonomous Mowing series. In the last blog, we introduced you to Nomad and shared the background and experience of ZAPT. This week we will share our safety story and introduce the safety features built into Nomad. In the future, we will have Stories from our Engineers and Stories from the Field as part of additional Blog series.
ZAPT’s parent company Zupt has a 15-year history of working offshore in many environments. In those 15 years, Zupt has maintained a 0.0 TRIR. This level of safety awareness translates over to ZAPT's engineering team that designed Nomad from the ground up to be very safe. As described below and in later blogs, we have multiple sensors and systems on Nomad that ensure safe autonomous operations.
Nomad has multiple control options. The control options are through radio, an app on your phone or tablet, or from a central monitoring station. Nomad has multiple emergency stop (E-Stop) systems with two manual E-Stop (big red buttons) located diagonally across from each other on the top of the mower. Additionally, Nomad has a local area remote control E-Stop button with a 500m (1,500ft) range. The unit can also be stopped by app or at any central control/monitoring station.
The sensors used (full coverage of the sensor suite will be reviewed in upcoming blogs) allow Nomad to see people, animals, cars, bikes, etc., to make decisions. These decisions are based on security protocols or around clients' HSE (Health, Safety, and Environmental) compliance requirements. A stated protocol is that if anyone (human or animal) comes within 5m (15ft) of Nomad when operating, it immediately shuts down the mowing deck, alerts all monitoring users, and stops all movement. If this person or animal continues to 3m (10ft) of the mower, the entire unit, including the engine, shuts down and a second alert is sent to all users.
The LiDAR system sees at least 100m, and the stereo camera systems automatically detect adults at 20m (60ft) and children at least 15m (45ft). Both “perception” systems know the relative speed and distance away from the mower a detected object is to quickly determine if this object is static (tree, park, bench) or dynamic (dog, cyclist).
Nomad communicates with the outside world with an industrial-grade cellular modem (think hot-spot on steroids) containing four separate SIM cards and dual redundant radios. These systems automatically switch to the most optimal cell phone signal based on the strength of the signal (Verizon, AT&T, T-Mobile, Sprint). Nomad has a “heartbeat” signal that it constantly sends out to identify its status, and if it determines any issues, it sends images of what is bothering it.
Nomad’s brain runs on two powerful processors that contain something the industry refers to as an autonomous software stack (Look for more information on ZAPT’s autonomous stack in an upcoming blog). This software is built around the industry-standard robotic operating system (ROS) that many autonomous cars and autonomous systems have used at some stage. Extensive testing of software, hardware, and integrated systems has been completed and will continue to ensure the safety of Nomad is unmatched.
In this article, we have introduced a couple of terms, such as perception and autonomous stack, that we will have a deeper dive into in upcoming blogs. In our next blog, we will explain in-depth how Nomad knows where it is.
