A spherical wheel robot or Ballbot—a robot that balances on an actuated spherical ball—is a new and recent type of robot in the popular area of mobile robotics. This paper focuses on the modeling and control of such a robot. We apply the Lagrangian method to derive the governing dynamic equations of the system. We also describe a novel Fuzzy Sliding Mode Controller (FSMC) implemented to control a spherical wheel mobile robot. The nonlinear nature of the equations makes the controller nontrivial. We compare the performance of four different fuzzy controllers: (a) regulation with one signal, (b) regulation and position control with one signal, (c) regulation and position control with two signals, and (d) FSMC for regulation and position control with two signals. The system is evaluated in a realistic simulation and the robot parameters are chosen based on a LEGO platform, so the designed controllers have the ability to be implemented on real hardware.
With the spread of COVID-19, significant emphasis has been placed on mitigation techniques such as mask wearing to slow infectious disease transmission. Widespread use of face coverings has revealed challenges such as mask contamination and waste, presenting an opportunity to improve the current technologies. In response, we have developed the Auto-sanitizing Retractable Mask Optimized for Reusability (ARMOR). ARMOR is a novel, reusable face covering that can be quickly disinfected using an array of ultraviolet C lamps contained within a wearable case. A nanomembrane UVC sensor was used to quantify the intensity of germicidal radiation at 18 different locations on the face covering and determine the necessary exposure time to inactivate SARS-CoV-2 in addition to other viruses and bacteria. After experimentation, it was found that ARMOR successfully provided germicidal radiation to all areas of the mask and will inactivate SARS-CoV-2 in approximately 180 s, H1N1 Influenza in 130 s, and Mycobacterium tuberculosis in 113 s, proving that this design is effective at eliminating a variety of pathogens and can serve as an alternative to traditional waste-producing disposable face masks. The accessibility, ease of use, and speed of sanitization supports the wide application of ARMOR in both clinical and public settings.
Pneumatic systems are used in a wide range of industrial robotic and automation systems due to their interesting properties. However, air compressibility, friction, and the other nonlinear characteristics of a servo pneumatic system are difficulties, which contribute to use modern controllers. Conventional linear controllers face steady-state error and uncertainty. Nonlinear modeling with model-based control is a good choice to deal with this problem. In this paper, behavior equation of flow and pressure, friction, and other nonlinear factors are studied. Afterward to reach precise position tracking and low steady error, sliding mode control is proposed. In this way, measurement of pressures and other states of system is required. To reduce the cost of using pressure sensor, observation of pressure with nonlinear high gain observer is suggested. It was seen that the new proposed approach solved the observability problem of servo pneumatic systems. Pressure signal of each sides of cylinder are observed simultaneously by measurement of piston position. Finally, stability of designed controller is studied in the presence of observed states. Experimental results validate the advantage of using designed controller-observer instead of conventional proportional–integral–derivative controller with different input signals in the presence of high friction actuator.
With the spread of COVID-19, significant emphasis has been placed on mitigation techniques such as mask wearing to slow infectious disease transmission. Widespread use of face coverings has revealed challenges such as mask contamination and waste, presenting an opportunity to improve the current technologies. In response, we have developed the Auto-sanitizing Retractable Mask Optimized for Reusability (ARMOR). ARMOR is a novel, reusable face covering that can be quickly disinfected using an array of ultraviolet C lamps contained within a wearable case. A nanomembrane UVC sensor was used to quantify the intensity of germicidal radiation at 18 different locations on the face covering and determine the necessary exposure time to inactivate SARS-CoV-2 in addition to other viruses and bacteria. After experimentation, it was found that ARMOR successfully provided germicidal radiation to all areas of the mask and will inactivate SARS-CoV-2 in approximately 180 seconds, H1N1 Influenza in 130 seconds, and Mycobacterium tuberculosis in 113 seconds, proving that this design is effective at eliminating a variety of pathogens and can serve as an alternative to traditional waste-producing disposable face masks. The accessibility, ease of use, and speed of sanitization supports the wide application of ARMOR in both clinical and public settings.
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