Robot for Positioning Sensors in a Plant-Growth Chamber

The Advanced Life Support Automated Remote Manipulator (ALSARM) is a three-degree-of-freedom robotic system that positions an array of sensors inside a closed-system hydroponic chamber used in research on the production of biomass and the use of hydroponic subsystems of life-support systems. The array includes sensors to measure the light intensity, air temperature, infrared temperature, relative humidity, and airflow. The ALSARM operates under either automatic control by a personal computer or manual control through a teaching pendant (essentially, a hand-held box that contains switches and indicators wired to a plug for connection to the rest of the ALSARM control circuitry). The motivation for developing the ALSARM was the need to eliminate the leakage of the chamber atmosphere and the potential for contamination associated with the prior practice of opening the chamber so that technicians could enter to take environmental measurements. One especially notable feature of the ALSARM is a horizontal telescoping arm, through which power and signal cables for the sensors are routed. The cables are extended and retracted with the motion of the telescoping sections by use of a servomotor and gravitation, respectively.