Aliza Che Amran

Optimization design and analysis of an underactuated dexterous robotic hand system

This paper presents the optimization of three-dimensional (3D) Printed Underactuated Dexterous Robotic Hand (UDRH) design and the analysis of the UDRH material. The UDRH design consists of three fingers and a thumb at which each finger has two links and two degrees of freedoms (DOF) and each joint of the finger is actuated by the DC Micromotor. The thumb has 3DOF to allow for adduction and abduction of the thumb. The robot hand is designed to be like human hand whereby higher performances in accuracy, stability and consistency can be achieved. The actuators are placed directly in each finger link so that the robot hand has several degrees of freedoms to achieve dexterous grasping. The angular rotation, speed, and torque have to be controlled for each individual joint to enable a more precise control. The structure of the UDRH robot hand is printed by using Flashforge Creator Pro 3D printer machine. In this paper, the optimization and analysis of fused deposition modeling (FDM) printed materials which are Acrylonitrile Butadiene Styrene (ABS), Polylactid Acid (PLA), Nylon, and Polycarbonate (PC) plastic are accomplished by testing for their stress and deformation through finite element analysis by using Solidworks software. From the analysis, the critical points and the parts of the UDRH design that are prone to damage under high force and temperature can be detected. In this study, ABS plastic material is chosen for UDRH prototype due to its properties which are resistance to heat which is 5.47 × 106N/m2, and high melting point of 210°C compared to the other materials.

A study on tracking peformance of the pneumatic system with enhanced NPID controller

An investigation on the performance of enhanced Nonlinear Proportional Integral Derivative (ENPID) controller is presented in this paper. The study is focused on the potential of the controller to perform well in tracking set point of pneumatic actuator system. Two control strategies of the ENPID are considered in this paper, namely Multi-rate NPID (MN-PID) and Self-regulation NPID (SN-PID). These control strategies are tested against NPID and conventional PID controller. Also, the dead-zone compensation (DZC) is applied to the system to overcome the dead-band of the valve. Feed forward path is also included to improve the tracking performance. Two different input signals i.e. sinusoidal and S-curve waveforms are used to evaluate the performance of the techniques. To further examine the controller performance, the frequency and amplitude of the sinusoidal test signal are varied. The effectiveness of the proposed controllers is verified through simulation and experimental studies.