Design and development of a Novel Soft Gripper Manipulated by a Robotic Arm

This study presents the design and development of a tendon-driven soft gripper manipulated by a 4 DOF robotic arm. The proposed robotic arm and the gripper explore the new areas focusing on increasing the grasping performance of the gripper as well as the workspace. The gripper is designed as a 3 finger and driven by tendons using two servo motors. The tension of the strings is adjusted using a pulley mechanism and a string. The opening and grasping of the soft gripper are accomplished by each motor. The wide opening allows the gripper to grasp wide objects. The parallel robotic arm motion is actuated by 4 motors. Each motor is mounted on a spherical shoulder plate while circular plates with angles axle extrusions are also attached to the motors. The axles are angled so that their axes of rotation converge to the center of the shoulder plate. The vertical and lateral motion of the robotic arm is controlled by the series linkages connected to the axles, thereby actuating the forearm of the mechanism. The robotic arm is 3D printed in polylactic acid (PLA) and the single piece designed soft gripper is 3D printed in thermoplastic polyurethane (TPU). The gripping force applied by the gripper is obtained using flexible sensors attached to the tip of the 3 fingers. The finite element analysis is performed in Ansys and the link lengths are optimized to trace the desired workspace. The mechanism is tested for its grasping and lifting of various objects showing promising superiorities in terms of its grasping capabilities mimicking the human hand. If the robotic arm is mounted on a moving platform, then it can serve as an assistive robot for the elderly

Design and Construction of 4-DOF EMG-Based Robot Arm System

Electromyography (EMG) provides an alternative way of providing signal responses from the muscle. As such, the recent trend in developing myoelectric devices has spark the interest in this specific field of study. This is because the traditional controllers lack in certain parts which reduce the utilization of limbs to control devices mainly the robotic arm. However, noise such as crosstalk, motion artifact, ambient noise and inherent noise have become a major issue when handling EMG signals. The preparation of electromyography requires more attention in terms of muscle group selection, electrode placement and condition of the surrounding as it will affect the signal output. The aim of this project is to develop a 4 degree-offreedom (DOF) robotic arm that can be controlled using EMG signals. The correlation between the EMG signal and the robotic arm are required to be identified in order to analyze the performance of robotic arm. Review on the actuator, electromyography methods and microcontroller are done to evaluate the techniques used from past researches. The methods of this project include hardware development of robotics arm, development of forward kinematic, sensor calibration and electrode positioning and experiment on classification and validation of EMG signals based on hand gestures. The experiment showed that the sampling rate and arm position affect the EMG signal output. In addition, the controllability of the robotic arm was low because the motors are controlled independently. The objective of the project has been achieved as the EMG-controlled robotic arm has been successfully developed. The robotic arm is still available for improvement by adding multiple channel sensors and implementing a wireless system

Design and Optimization of Industrial Manipulator

Industrial Manipulator is very widely used device in Automation, it is an essential motion subsystem component of robotic system for positioning, orientating object so that robot can perform useful task in automation. The main objectives of this project are to design and implement a 4-DOF pick and place object. This project can be self-operational in controlling, stating with simple tasks like gripping, lifting, placing and releasing. In this project, the goal is on 4-DOF of articulated arm. Articulated arm is having revolute joints that allowed angular rotation between adjacent joint. Four servo motors have been used in this project to perform four degree of freedom (4-DOF). There are numerous dimensions over which robotic arms can be analyzed, such as torque, payload, speed, range, repeatability and cost, to name a few. Manipulators are designed to execute required movements. Their controller design is also equally important. The manipulator arm is controlled by serial servo controller circuit boards. The controller have been used for servo motor actuation is at mega 16 Development board

Development of hybrid force-position controller for ultrasound-guided breast biopsy robotic system

Conventional ultrasound-guided breast biopsy (UGBB) procedure is commonly performed to assess abnormal masses within the breast. It requires a radiologist to handle multiple devices at once, which could reduce the abilities in performing such procedure resulting in radiologist’s fatigue, compromised breast tissue due to multiple insertions and susceptibilities to pneumothorax complication for the patient. Previous studies have reported that many of the restrictions associated with handheld minimally invasive methods were tackled when physician assist instruments were used. Therefore, the purpose of this research is to assist radiologist in conventional UGBB procedure by introducing a semi-automated robotic system to maintain desired contact force between the ultrasound transducer and the breast. For that reason, a hybrid force/position controlled UGBB robotic system has been developed in simulation environment. The UGBB robotic system involves a 5 degree of freedom (DOF) articulated robot arm to control the transducer movement, a force/torque (F/T) sensor system to measure the contact force, an ultrasound machine to view the inside structure of the breast tissue and a computer-based control system. As such, the RV-2AJ robotic arm has been modelled with its positional accuracy of almost 100%. A breast model based on a medical grade breast phantom has been established with a mean error of 0.69% by using black-box modelling approach. Motion disturbance from human respiration has been explored as well since it plays a significant element that would affect the stability of the system to constantly maintain low contact force on the breast.Finally, intelligent Fuzzy-PID hybrid force/position controller has been successfully established to maintain low contact force on identified breast stiffness characteristics. The overall hardware-based simulation shows promising outcomes with almost no overshoot, fast rise time, high robustness and stability on different environment condition. In conclusion, the success of this work serves as significant foundations for long-term related research, especially in the development of UGBB robotic system and approaches of force control mainly for human-robot interaction

Motion planning with dynamics awareness for long reach manipulation in aerial robotic systems with two arms

Human activities in maintenance of industrial plants pose elevated risks as well as significant costs due to the required shutdowns of the facility. An aerial robotic system with two arms for long reach manipulation in cluttered environments is presented to alleviate these constraints. The system consists of a multirotor with a long bar extension that incorporates a lightweight dual arm in the tip. This configuration allows aerial manipulation tasks even in hard-to-reach places. The objective of this work is the development of planning strategies to move the aerial robotic system with two arms for long reach manipulation in a safe and efficient way for both navigation and manipulation tasks. The motion planning problem is addressed considering jointly the aerial platform and the dual arm in order to achieve wider operating conditions. Since there exists a strong dynamical coupling between the multirotor and the dual arm, safety in obstacle avoidance will be assured by introducing dynamics awareness in the operation of the planner. On the other hand, the limited maneuverability of the system emphasizes the importance of energy and time efficiency in the generated trajectories. Accordingly, an adapted version of the optimal Rapidly-exploring Random Tree algorithm has been employed to guarantee their optimality. The resulting motion planning strategy has been evaluated through simulation in two realistic industrial scenarios, a riveting application and a chimney repairing task. To this end, the dynamics of the aerial robotic system with two arms for long reach manipulation has been properly modeled, and a distributed control scheme has been derived to complete the test bed. The satisfactory results of the simulations are presented as a first validation of the proposed approach.Unión Europea H2020-644271Ministerio de Ciencia, Innovación y Universidades DPI2014-59383-C2-1-

Robot Autonomy for Surgery

Autonomous surgery involves having surgical tasks performed by a robot operating under its own will, with partial or no human involvement. There are several important advantages of automation in surgery, which include increasing precision of care due to sub-millimeter robot control, real-time utilization of biosignals for interventional care, improvements to surgical efficiency and execution, and computer-aided guidance under various medical imaging and sensing modalities. While these methods may displace some tasks of surgical teams and individual surgeons, they also present new capabilities in interventions that are too difficult or go beyond the skills of a human. In this chapter, we provide an overview of robot autonomy in commercial use and in research, and present some of the challenges faced in developing autonomous surgical robots