A systematic method to select gains of a discrete proportional-integral-derivative (PID) controller is presented. The PID controller with the gains obtained by the proposed method can robustly control nonlinear multiple-input-multiple-output (MIMO) plants in a second-order controller canonical form, such as robot dynamics. This method has been made possible by the finding that the discrete PID control is equivalent to the discrete form of time-delay control (TDC), a robust control method for nonlinear plants with uncertainty. By using this equivalence relationships are obtained between PID gains and parameters of TDC, which enable a systematic method for the select PID gains. In addition, based on the systematic method, a simple and effective method is proposed to tune PID gains applicable to nonlinear plants with inaccurate models. This method incorporates a set of independent tuning parameters that is far less than those for conventional methods for PID gain selection. The usefulness of the proposed methods is verified through the ease and simplicity of determining PID gains for six degrees-of-freedom (DOF) programmable universal machine for assembly (PUMA)-type robot manipulator; the effectiveness of these PID gains is confirmed by the adequate and robust performance through experimentation on the robot.
1 February 2018 in Robotics and Computer-Integrated Manufacturing
ArmAssist (AA), developed by TECNALIA, is a telerehabilitation platform aiming to help poststroke subjects maintain the rehabilitation of the upper limb at home. AA includes robotic modules with multiple sensors to train and measure the users’ voluntary movements. An assessment platform based on serious games is also included to not only engage the user but also perform automated evaluations of arm and hand function and their evolution over time. Moreover, AA facilitates at-home rehabilitation with limited remote supervision by the therapist. In the present article, the technical specifications and developments of AA are described. Additionally, a summary of the outcomes of a usability evaluation of AA is presented.
Recently, there has been an increase in the development of fire searching robots for indoor spaces such as the basements of buildings. This paper presents the control architecture for a fire searching robot using task oriented design (TOD) methodology. TOD is the systematic methodology used to design a system which follows a purpose closely by specifying a target clearly. As indoor spaces are blocked by walls, dangerous fires with smoke, high temperatures, and the possibility of explosions make it difficult for fire fighters to gain access to the fire. For this reason, a fire searching robot is developed in this study. It takes the place of fire fighters by means of an analysis of the properties of the environment of a fire, as well as the tasks demanded by the situation. For a stable operation, the fire searching robot is controlled by remote control. The control system is divided into three parts. The first is the robot controller, the second is a controller for the remote operating device, and the third is a wireless communication system. The appropriate hardware and software was developed for each part of the control system, and the fire search robot was tested in a test environment. The tests validated the performance and usefulness of the proposed control architecture