China
Africa
Explore chapters and articles related to this topic
Electrical, Electronic, and Electromechanical Systems
Published in Ramin S. Esfandiari, Bei Lu, Modeling and Analysis of Dynamic Systems, 2018
In all but the smallest motors, the magnetic field is established by a current in separate field windings on the stator. For an armature-controlled DC motor, a constant current source is supplied to the field windings and the applied armature voltage, va, varies. Another way of controlling a DC motor is to keep the armature current ia constant, while varying the voltage applied to the field windings. A simple model of a field-controlled DC motor is shown in Figure 6.47, in which the shaft in the mechanical subsystem is assumed to be massless, rigid, and undamped. The electrical part is represented by a field circuit, where Rf is field resistance, Lf is field inductance, vf is field voltage, and if is field current. Note that there is no back emf created in the field circuit. The torque generated by the motor is proportional to the field current, () τm=Ktif
Design and analysis of smart assistive humanoid robot for isolated patients
Published in Australian Journal of Mechanical Engineering, 2023
Dhruba Jyoti Sut, Prabhu Sethuramalingam
Studies of healthcare robots show promise for developing intelligent assistants that can provide nursing care in indoor settings. Sarder et al (Sarder, Ahmed, and Shakhar 2017). designed and implemented ‘OshoBOT,’ a lightweight telepresence robot controlled via built-in Wi-Fi and the Skype framework for video interaction. Their research showed that such robots have the potential to provide nursing care and improve patient outcomes. The push-pull system was used to drive the differential drive wheels. A mathematical model of an armature-controlled DC motor was used to do the control system stability analysis. Lag correction reduces the discrepancy between the system’s input and output. The robot achieves adequate stability in most scenarios due to the adoption of the differential drive system. Shunsuke Kumagai et al (Kumagai et al. 2016). have completed a robot that is nice to people. They developed a unique passive collision suppression mechanism for the elbow and wrist to ensure human safety during robot-to-object/human collisions. They built the robot’s entire outer body by covering it with an air-filled bag composed of a 0.15 mm thick polyethylene sheet. Each suppression mechanism has a shaft encoder to detect collisions, and air pressure sensors have been fitted in eight locations on the base at a 45-degree interval.