Mohamed Fanni

Tele-operated propeller-type climbing robot for inspection of petrochemical vessels

The purpose of this paper is to propose a new propeller-type climbing robot called EJBot for climbing various types of structures that include significant obstacles, besides inspection of industrial vessels made of various materials, including non-ferromagnetic material. The inspection includes capturing images for important spots and measuring the wall thickness.,The design mainly consists of two coaxial upturned propellers mounted on a mobile robot with four standard wheels. A new hybrid actuation system that consists of propeller thrust forces and standard wheel torques is considered as the adhesion system for this climbing robot. This system generates the required adhesion force to support the robot on the climbed surfaces. Dynamic simulation using ADAMS is performed and ensures the success of this idea.,Experimental tests to check the EJBot’s capabilities of climbing different surfaces, such as smooth, rough, flat and cylindrical surfaces like the real vessel, are successfully carried out. In addition, the robot stops accurately on the climbed surface at any desired location for inspection purposes, and it overcomes significant obstacles up to 40 mm.,This proposed climbing robot is needed for petrochemical and liquid gas vessels, where a regular inspection of the welds and the wall thickness is required. The interaction between the human and these vessels is dangerous and not healthy due to the harmful environment inside these vessels.,This robot utilizes propeller thrusts and wheel torques simultaneously to generate adhesion and traction forces. Therefore, a versatile robot able to climb different kinds of structures is obtained.

Novel Contactless Active Robotic Joint Using AMB: Design and Control

This paper investigates the design, modelling and control of a novel contactless active robotic joint using active magnetic bearing (AMB). A robot with such joint avoids dust generation, oil lubrication and friction. This makes such robot suitable for applications in clean environments such as clean and surgery rooms. Also, such joint can be used in space robots, self-reconfiguration robots and robots with selective compliance. In contrast to the passive joint with AMB that needs the control of 5 degree-of-freedom (DOF), the proposed joint here needs the control of 6-DOFs. The additional variable to be controlled is the robot joint angle. Frameless, brushless, direct drive, high torque DC motor (BLDC) is used to control the robot joint angle. A contactless sensor for robot joint angle measurement is proposed. The mutual interaction between the control of the BLDC motor and the AMB is studied. Although in this paper tracking control of the robot joint angle and stabilization of the other 5-DOFs to their null values are carried out, it is possible to carry out tracking control of all the 6-DOFs. This leads to enlarge the mobility of the joint from 1-DOF to 6-DOFs. Feedback linearization controller is used to track the robot joint angle desired trajectory. State feedback controller is used to stabilize the AMB. The proposed system is designed and simulated using CATIA and MATLAB/Simulink. The results prove the feasibility of the proposed robotic joint from design and control view points.Copyright

Workspace mapping and control of a teleoperated endoscopic surgical robot

This paper presents the experimental implementation of a teleoperated endoscopic surgical manipulator system that uses PHANTOM Omni haptic device as the master. The 4-DOF, 2-PUU 2-PUS, endoscopic surgical parallel manipulator design is carried out using screw theory and Parallel virtual chain methodology to have larger bending angles and workspace volume. The master and slave devices of the teleoperation system are dissimilar in their kinematics and workspace volumes. A workspace mapping technique is implemented based on Position with Modied Rate Control to navigate through the slave workspace without annoying the user. To control the motion of the slave robot, a PID controller is used. The experimental results show the feasibility of the teleoperation surgical system using the 4-DOF parallel manipulator. Also, they indicate the efficiency of the implemented mapping technique and the designed controller to span the slave workspace with high dexterity and good tracking which allows the surgeon to perform the operation with high accuracy.

Geometrical/analytical approach for reciprocal screw-based singularity analysis of a novel dexterous minimally invasive manipulator

Abstract This paper is concerned with the singularity analysis of a novel 4-DOF endoscopic surgical parallel manipulator (2-PUU_2-PUS). This parallel manipulator has larger bending angles compared to previously existing surgical parallel manipulators. It is easy to imagine the singular configurations inside the workspace of a manipulator with a zero pitch and infinity pitch reciprocal screws. On the other hand, the (2-PUU_2-PUS) surgical manipulator has two reciprocal screws of h-pitch. Hence, the singular configurations of this manipulator could not be provided by the known reciprocal screw-based geometrical approach. Therefore, the geometrical/analytical approach for reciprocal screw-based singularity analysis of 2-PUU_2-PUS is proposed in this work. The results illustrate the feasibility of the proposed algorithm to find all singular configurations of the 2-PUU_2-PUS manipulator. The discovered singularity configurations greatly shrink the singularity-free workspace to be one-fourth of the original workspace. In order to be able to work through the entire workspace, we suggest changing the topology structure of the manipulator.

An intelligent Q-parameterization control design that captures non-linearity and fuzziness of uncertain magnetic bearing system

This paper presents a systematic procedure to design a robust gain scheduled Q-parametrization Takagi-Sugeno (TS) fuzzy controller for non-linear magnetic bearing system with imbalance. First, a mathematical model of non-linear magnetic bearing model is presented. Second, the system is linearized around various operating points to overcome the model non-linearity by increasing the operating envelop. Third, the Q-parametrization observer based stabilizing controller with TS fuzzy systems is explained which combines both the intelligence of fuzzy systems and robustness of Q-parametrization. Forth, the proposed controller is applied to a non-linear magnetic bearing system. Finally, the simulation results are presented. The results manifest the ability of proposed controller to overcome the model non-linearity by increasing the dynamic operating range up-to more than 80% of gap length and reject imbalance disturbances under different speeds.

Controller Design of a New Quadrotor Manipulation System Based on Robust Internal-Loop Compensator

This paper introduces control design of an aerial manipulator which consists of 2-link manipulator attached to the bottom of a quad rotor. This new system presents a solution for the limitations found in the current quad rotor manipulation system. The proposed robot enables the end effector to achieve any arbitrary position and orientation, and thus it increases its degrees of freedom from 4 to 6. Also, it provides enough distance between the quad rotor and the object to be manipulated. To study the feasibility of the proposed system, a quad rotor with high enough payload to add the 2-link manipulator is designed and constructed. The system parameters are identified to be used in the simulation and controller design of the proposed system. System modeling are described briefly. The controller of the proposed system is designed based on Robust Internal-loop Compensator (RIC) and compared to Fuzzy Model Reference Learning Control (FMRLC) technique which was previously designed and tested for the proposed system. These controllers are tested in order to achieve system stability and trajectory tracking under the effect of picking/placing a payload as well as under the effect of changing the operating region. Simulation framework is implemented in MATLAB/SIMULINK environment. Simulation results verifies the effectiveness of the proposed control technique.

Micro/macro-positioning control of a novel contactless active robotic joint using active magnetic bearing

In this paper the micro/macro-positioning control of a novel contactless active robotic joint using active magnetic bearing (AMB) is presented. In clean environments, such as surgery or clean rooms, the use of robots with this novel joint is useful to avoid friction, dust generation, and oil lubrication. Moreover, this kind of robots can be used in the applications that need high precision micropositioning control such as semiconductor wafers manipulation to form semiconductor devices. The novel robotic joint used in this paper is designed using finite element method. This joint has 6 degrees-of-freedom (DOFs), 1-DOF for robot joint roll angle and 5-DOF for AMB. The robot joint roll angle is controlled in macro-scale accuracy. The macro-scale positioning of the joint roll angle is needed for gross motion like normal robot revolute joint. The other 5-DOF of the joint are controlled like AMB with the different that the target pitch and yaw angles as well as the axial, vertical and horizontal movements are different than zero but in micro-scale range. The robot joint roll angle is controlled using a PID-based Feedback linearization controller, while a state feedback controller with integral term is used for controlling the AMB 5-DOFs. The micro/macro-positioning control of the novel robotic joint is implemented using MATLAB/Simulink. The robustness of the controllers is tested against payload variations. The results demonstrate that the proposed novel robotic joint is feasible and valid in the applications that need high precision micro-macro-positioning control.

Parametric design and analysis of a new 3D compliant manipulator for micromanipulation

This paper introduces a parametric design of a new 3D compliant parallel manipulator based on pantograph linkage for micro/nano applications. Furthermore, the modal shapes and natural frequencies analysis are carried out versus the flexure joint parameters which are a crucial point for the controller selection/design and geometry optimization. The new compliant manipulator provides decoupled 3DOF translational motion with fixed orientation of the end effector and it has significantly high workspace to size ratio. The modified manipulator aims to enlarge the workspace by enhancing the values of magnification factors of input motion and by reducing the parasitic motion and geometric stiffening of the original manipulator. The main parameters that affect the performance of the compliant manipulator are determined based on the generated results of finite element analysis which is performed using ANSYS software. The results have successfully demonstrated the improvements of the proposed manipulator in terms of workspace size, magnification factors, joint stiffening and parasitic motions.

Macro/micro-positioning control and stability analysis of contactless active robotic joint using active magnetic bearing

In clean environments, such as surgery or clean rooms, the robots with conventional joints are source of friction, dust generation, and oil lubrication. To overcome this problem, robots with contactless active robotic joint using active magnetic bearing (AMB) can be used. Moreover, this proposed kind of robots can be used in the applications that need high precision micropositioning control such as semiconductor wafers manipulation to form semiconductor devices. In this paper the macro/micro-positioning control of a novel contactless active robotic joint using active magnetic bearing is presented. In addition, the stability analysis of the controller is studied. The robotic joint used in this paper is designed using finite element method. This joint has 6 degrees-of-freedom (DOFs), 1-DOF for robot joint roll angle and 5-DOF for AMB. The robot joint roll angle is controlled in macro-scale accuracy. The macro-scale positioning of the joint roll angle is needed for gross motion like normal robot revolute joint. The other 5-DOF of the joint are controlled like AMB with the different that the target pitch and yaw angles as well as the axial, vertical and horizontal movements are different than zero but in micro-scale range. The robot joint roll angle is controlled using a PID-based Feedback linearization controller, while a state feedback controller with integral term is used for controlling the AMB 5-DOFs. The macro/micro-positioning control of the novel robotic joint is implemented using MATLAB/Simulink. The robustness of the controllers is tested against payload variations. The results demonstrate that the proposed novel robotic joint is feasible and valid in the applications that need high precision macro-micro-positioning control.

Towards a hybrid brain based robot

Autonomous robots performing various tasks without human guidance have always been our dream for a better future. A problem that faces autonomous robots is dealing with novel situations. One of the recent technologies that has proven its ability to deal with such situation is Brain-Based Device(BBD). However, the large computational power needed to simulate its nervous system is a major limitation. To overcome this problem, this paper presents a hybrid system that consists of neuronal and non-neuronal areas. In non-neuronal areas, computer vision algorithms are used to extract some features from images. While neuronal-areas are connected together based on a detailed neuroanatomical structure to mimic the human learning process. OpenCV is used for extracting features and obtaining invariant object-recognition. Nengo python package is used for simulating neuronal areas in the system and monitoring activities of neuronal units. Moreover, the successful integration of the subsystems leads to the perceptual categorization based on invariant object-recognition of various visual cues. The time needed for the simulation is significantly decreased compared to the BBDs in the literature.