Efficient Autonomous Navigation for Planetary Rovers with Limited Resources

Rovers operating on Mars are in need of more and more autonomous features to ful ll their challenging mission requirements. However, the inherent constraints of space systems make the implementation of complex algorithms an expensive and difficult task. In this paper we propose a control architecture for autonomous navigation. Efficient implementations of autonomous features are built on top of the current ExoMars navigation method, enhancing the safety and traversing capabilities of the rover. These features allow the rover to detect and avoid hazards and perform long traverses by following a roughly safe path planned by operators on ground. The control architecture implementing the proposed navigation mode has been tested during a field test campaign on a planetary analogue terrain. The experiments evaluated the proposed approach, autonomously completing two long traverses while avoiding hazards. The approach only relies on the optical Localization Cameras stereobench, a sensor that is found in all rovers launched so far, and potentially allows for computationally inexpensive long-range autonomous navigation in terrains of medium difficulty

Flex-Ro: A Robotic High Throughput Field Phenotyping System

Research in agriculture is critical to developing techniques to meet the world’s demand for food, fuel, fiber, and feed. Optimization of crop production per unit of land requires scientists across disciplines to collaborate and investigate new areas of science and tools for data collection. The use of robotics has been adopted in several industries to supplement labor, and accurately perform repetitious tasks. However, the use of autonomous robots in commercial agricultural production is still limited. The Flex-Ro (Flexible structured Robotic platform) was developed for use in large area fields as a multipurpose tool to perform monotonous agricultural tasks. This work presents the design and implementation of the control system for the Flex-Ro machine. The machine control architecture was developed for safe operation with redundant emergency stops and checks. Operators use the remote-control device to maneuver the machine in uncontrolled environments. Autonomous field coverage was developed using global positioning system (GPS) guidance. The guidance system tracked within 4 cm of the guidance line 95% of the time at a travel speed of 4 kph. Waypoint guidance was implemented and demonstrated such that Flex-Ro could be programmed to follow complex paths and curves. High-throughput plant phenotyping is a continuously developing and evolving field of plant science. The methods used to collect phenotyping data include drones, satellites, manual measurement, and ground rovers. A suite of phenotyping sensors was installed onto the Flex-Ro to cover large field areas. The system was verified in soybean research plots at the University of Nebraska-Lincoln (UNL) Spidercam phenotyping facility. Positive correlations between the Spidercam and Flex-Ro phenotyping data were established. The Flex-Ro was able to statistically distinguish between soybean variety emergence and maturity differences. The late season phenotyping data showed statistical differences between the fully irrigated versus deficit plots. Basic economic calculations estimated the cost to operate the Flex-Ro machine for field phenotyping use at approximately $5.50/ha. Advisor: Santosh K. Pitl

Hybrid PSO-cubic spline for autonomous robots optimal trajectory planning

This paper presents a new version of the Particle Swarm Optimization algorithm where the particles are replaced by spline functions. The developed algorithm generates smooth motion trajectories with two times continuously differentiable curvature avoiding obstacles placed in the workspace. It can be used for autonomous robot path planning or transport problems. The spline based trajectory generation gives us continuous, smooth and optimized path trajectories. Simulation and experimental results demonstrate the effectiveness of the proposed method.info:eu-repo/semantics/publishedVersio

Iowa Motorcycle Operator's Manual, 2014

The rules and regualtions for owning and operating a motorcycle in Iow