Development of a Power Assist Lifting Device With a Fuzzy PID Speed Regulator

This paper introduces the development of a one-degree-of-freedom (1DOF) power assist device that helps to lift objects and facilitate the operator's job. The existing designs were examined for different control approaches and human-robot cooperation intuitiveness. The project involves the mechanical design of the experimental setup and development of advantageous control system. Since a task for the device is highly dependent on the mass of handling object, an adaptive strategy is a major concern of control system design. The controller design is represented by two loops to control admittance and velocity. To reduce the response time of the device, two velocity controllers are designed and compared with the embedded one. The first is a conventional proportional-integral-derivative controller which has shown better performance than the native controller. The second is derived from the first using fuzzy logic for better handling of different manipulation scenarios. The results illustrate that a faster response of the device can be achieved using a fuzzy logic controller due to the nonlinear nature that allows adapting to changes in velocity error and applied load.