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A Prototype Capacitive Sensor-Based Robot Safety System.

Center for Manufacturing Productivity and Technology Transfer, Rensselaer Polytechnic Institute, Troy, New York, :36 pages
Research was reported concerning the protection of workers from robots by the use of intelligent sensors. A capacitive proximity sensor was studied specifically as a component of a safety sensor system. Deviations in the electric field surrounding the capacitive sensor were used to detect intruding objects/humans. These deviations in the 4 to 9 hertz frequency bandwidth corresponded to movements of humans in the work envelope of the robot. Output from the sensor was sent to an emergency stop device if a person intruded on the path of the robot, enabling humans to work safely in near proximity to robots for purposes of trouble shooting or programming. Both the computer signal processing and human spectral filtering systems were improved in this research over earlier technology. System components described included antenna design, sensor electronics (oscillator, capacitive bridge, signal detection circuitry, and power supplies), and control electronics (computer signal processing, human spectral filter electronics, automatic nulling circuitry, robot control, and sensor interfaces/multiple sensor integration). System operation was described including operation overview, assembly, installation, delay operation, and environmental considerations such as electromagnetic interference transmissions and interactions and air quality effects. During testing, the robot stopped moving when a person was about 18 inches from the end effector antenna.
NIOSH-Contract; Contract-86-0244; Safety-research; Factory-workers; Automation; Work-practices; Workplace-studies; Industrial-safety; Industrial-environment; Electrical-waves;
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Center for Manufacturing Productivity and Technology Transfer, Rensselaer Polytechnic Institute, Troy, New York, 86-15 DSR, P. O. No. 86-0244, 36 pages, 10 references
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division