Roktrack Is a Solar-Powered, Weed-Eating Robot

People seem to be constantly looking for the next technology or gadget that can save them time, money, or simply make theirs lives easier. Smart home technology is a perfect example of this. Robotic vacuum cleaners became one of the first smart home devices to gain wide spread acceptance amongst the general public. An owner could be at work, be at home watching television, or be out of town and they would have the peace of mind knowing that when they get home, their floors would be just as clean as when they left. It makes sense then that robotic lawn mowers are also beginning to gain some popularity. Cutting the lawn is generally more labor intensive and time consuming. These generally work similar to the robotic vacuum cleaners such that they are battery-powered and have a charging station they will return to when their battery is low. However, Yuta Suito has recently demonstrated his own spin on a robotic lawn mower that uses solar power as the source of energy.

Called the Roktrack, the self-guiding robot was built specifically for chopping down weeds. It operates by staying within an area defined by pylons (traffic cones) which can be as large as 50m x 50m. Employing a Raspberry Pi and a wide angle camera, it uses object detection to spot the location of a cone and move towards it to within some specified distance. Next, it will turn and find the next cone and begin moving towards that one. This pattern will repeat continuously while the Roktrack slowly moves inward until it reaches the center of the area and the area is free of weeds (and grass).

Underneath the device houses two cutting blades which are designed to gracefully handle any pebbles that may get rolled over. In addition, the blades are made of a combination of metal and nylon cord which keeps any weeds from getting tangled around the motor shaft. Overall, it makes for a robust design that can handle weeds and grass as tall as 15cm. The combination of tires and treads on the Roktrack also enables it to handle the rougher surfaces that may be encountered in a yard. It can crawl over bumps or obstacles up to 5cm without issue.

For power, 18V-4.2W solar panels are used along with a 12V solar charger to keep a 12.8V LiFePO4 battery charged. The combination allows it to run for up to three hours on a full charge and up to one hour a day if the battery is depleted and the robot is relying on solar power alone to charge its batteries (given it is a sunny day). Additional experiments are being done which tests two robots working together simultaneously in an area. Using the object detection two Roktracks can successfully work together and avoid collision to tackle a single area. Furthermore, using a type of pulley system and two robots, the device can work together to operate over steep inclines. They complete the task by operating with a push-pull technique which helps each one maneuver up and down the incline simultaneously.

For more information on the project including pictures, details on the build, and a list of components used, check out Suito's write-up.