An Autonomous Robot for Field Transport of Strawberries

Project SummaryWe propose to continue the research and development of a four-wheeled autonomous agricultural robot that, while light-weight and affordable, can assist in harvesting by transporting produce from a human picker in the field to a collection station at the edge of the field thus increasing picker productivity by 50%.Our primary focus for this effort will be on the harvesting of strawberries. In California alone, more than 2 billion pounds of strawberries are harvested each year with a value of over $2 billion. The commodity nature of this crop applies pressure on the farmers to keep prices low, yet at the same time labor shortages are growing because picker jobs are unattractive to most Americans. Each picker harvests about $65,000 worth of strawberries per year, so increasing each picker's productivity by 50% allows them to pick an additional $32,000 worth of strawberries per year. Therefore farmers are highly motivated to adopt technology to boost picker efficiency.In the field, pickers do a very complex picking, sorting, and packing task that will take years to automate. However, in the traditional manual harvest scenario, pickers spend about 1/3 of their time transporting a full box of berries along their furrow to the nearest roadway and from there to a nearby station for inspection, payment registration, and stacking on pallets. Offloading this 1/3 non-picking transport time increases the picker's picking time by 50%.We have been working with a nearby strawberry farm, Terry Farms, to define an autonomous robot that can relieve the picker from the transport task to allow them to focus full time on the picking, sorting, and packing task which is their highest value add. The robot must be safe, affordable, and require a minimum of focus from the picker. The robot must be rugged, low power, lightweight, be capable of carrying a 10 pound box of strawberries and be able to operate for hours without recharging. Prior to and during the Phase I effort, we have designed and constructed the hardware and firmware for a prototype that meets these specifications. During Phase I, we began developing the guidance and control software.The complexity of robot autonomy includes image processing, scene understanding, predictive modeling, and path planning. Robot autonomy in a complex and unstructured environment is beyond the scope of an SBIR effort. However, strawberry fields and their surrounding roads are very regular, so the software task is tractable. By the end of Phase I we demonstrated furrow tracking, collision avoidance, picker following, and picker leading capabilities. We propose here to continue the advancement of the control software. By the end of Phase II we will demonstrate autonomous operation including hand-off in the field, obstacle accommodation, collection station identification, hand-off at the collection station, return-to-my-picker, and pack-up-and-go-home behaviors. Phase II will include field trials with multiple robots, each interacting with its own picker team and with the common inspection station.This effort utilizes the expertise at Tanner Research in mechanical design, power electronics, firmware, and software development including image processing, tracking, and advanced algorithms with large data and throughput requirements. For this work, we will augment our internal team with specific robot expertise from our collaborators at Caltech, Prof. Joel Burdick, and his graduate students.We expect to commercialize the results first with our lead customers Terry Farms and Driscoll's, and then, after rapid refinement, expand the roll-out to strawberry farmers statewide and worldwide. We expect to adapt the robot to other applications including transport of other crops, data gathering such as rapid phenotyping, picking, planting, weeding, and pest remediation.