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This paper describes the design of a light-weight and compact robotic gripper for automated harvesting of crops, including vegetable crops such as tomatoes, cucumbers, green onion, radish, and lettuce, growing in biomass production chambers. Because these crops vary significantly in their shape, size and rigidity, the gripper features soft fingertips with embedded grasping force sensor, a two degree-of-freedom (DOF) parallel jaw to facilitate alignment with crop objects to be harvested, and a two-DOF parallel cutting device to ensure complete separation of crop objects from plants during harvesting. A microcontroller system is integrated into the gripper for control of grasping and cutting.

A robot end effector is described in this paper that has been designed for NASA's Bioregenerative Planetary Life Support Systems Test Complex (BIO-Plex). An adapter concept allows the end effector to carry different types of sensor/probe modules and plant sampling mechanisms. These adapter modules will provide rapid and automatic configuration for a variety of tasks ranging from measurement of environmental conditions to tissue sampling and storage. In the paper, the prototype end effector and climatic sensors adapter that have been constructed are described, along with the biomass production robot system with which it is integrated.

This paper discusses the development and testing of a high-output Fluorescent Light Module for use in the Commercial Plant Biotechnology Facility on board the International Space Station. Methods of optimizing the system efficiency of the light module are discussed. A detailed description of the design is presented. A proto flight unit has been tested and evaluated for photon flux output and thermal management.

Conducting research to assess the impact of microgravity on plant growth and development requires a plant growth unit that has the capability to provide an enclosed, controlled environment chamber. Since plants are sensitive to a number of atmospheric gaseous materials, the chamber's atmosphere must be isolated from the space vehicle atmosphere. The plant growth unit must also be capable of removing any deleterious materials that may affect plant growth and development. The ASTROCULTURE™ plant growth unit (ASC-8), developed by Wisconsin Center for Space Automation and Robotics (WCSAR) at the University of Wisconson, was used to provide the desired environmental conditions required to support plant growth experiment during 9-day STS-95 mission. Effective control of chamber temperature, chamber humidity, plant water and nutrients delivery, and chamber carbon dioxide was maintained during the entire mission.

The demand for highly flexible manipulation of plant growth generations, modification of specific plant processes, and genetically engineered crop varieties in a controlled environment has led to the development of a Commercial Plant Biotechnology Facility (CPBF). The CPBF is a quad-middeck locker playload to be mounted in the EXPRESS Rack that will be installed in the International Space Station (ISS). The CPBF integrates proven ASTROCULTURE” technologies, state-of-the-art control software, and fault tolerance and recovery technologies together to increase overall system efficiency, reliability, robustness, flexibility, and user friendliness. The CPBF provides a large plant growing volume for the support of commercial plant biotechnology studies and/or applications for long time plant research in a reduced gravity environment.

Automation of space-based scientific operations minimizes the crew time needs for experiments while increasing the efficiency and quality of science operations. ORBITEC has completed the development of a space qualifiable prototype of a Shared Multi-Use Remote Robotics Facility (SMURRF). SMURRF, sized for a Middeck Locker (MDL) application, provides a simple, flexible, and functional manipulator to assist space operations, in manned or unmanned modes, carried out in lockers or racks onboard the Space Shuttle and the International Space Station (ISS). It will be primarily operated in an automated mode with additional remote command/control capability from the ground or from space. Ground trials have demonstrated that many operations can be autonomously performed without the presence of a human operator.

Maintaining thermal balance in a space-based plant chamber has proven to be difficult to achieve, particularly if the air temperature in the plant chamber is desired to be below that of the atmosphere of the space vehicle. Analysis of the thermal condition of a plant chamber has identified three heat sources as major contributions to this serious problem. The first is the input of radiant energy into the chamber required to support plant growth. The second is via thermal conduction through the chamber walls. The last major thermal input is from the fans and other electronic components embedded inside the chamber. Design solutions to achieve thermal balance are further exacerbated by virtue of the limited power availability, volume and mass restrictions, and safety considerations.

The ASTROCULTURE™ (ASC) middeck flight experiment series was developed to test and integrate subsystems required to grow plants in reduced gravity, with the goal of developing a plant growth unit suitable for conducting quality biological research in microgravity. Flights on the Space Shuttle have demonstrated control of water movement through a particulate rooting material, growth chamber temperature and humidity control, LED lighting systems and control, recycling of recovered condensate, ethylene scrubbing, and carbon dioxide control. A complete plant growth unit was tested on STS-63 in February 1995, the first ASC flight in which plant biology experiments were conducted in microgravity. The methods and objectives used for control of environmental conditions in the ASC unit are described in this paper.

The adaptation to changes in human operator dynamics and changes in working environment dynamics can be an important issue in designing high performance telerobotic systems. This paper describes an approach to force control in telerobotic hand systems in which model reference adaptive control techniques are used to adapt to changes in human operator and working environment dynamics. The techniques have been applied to force-reflective control of a single degree-of-freedom telerobotic gripper system at Wisconsin Center for Space Automation and Robotics (WCSAR). This adaptive gripping system is described in the paper along with results of experiments with human subjects in which the performance of the adaptive system was analysed and compared to the performance of a conventional non-adaptive system. These experiments emphasized adaptation to changes in compliance of gripped objects and adaptation to the on-set of human operator fatigue.