Mazhar Ul Haq

Inverse Kinematic Analysis of Three Link Mechanism for Fin Actuation of Fish Like Micro Device

In this paper, inverse kinematic analysis of a proposed three link mechanism of a bio-inspired micro scanning device towed underwater by a surface vessel to actuate its aileron fins for its depth control and for its stabilization against roll is performed. Mechanism is actuated by IPMC actuators. To speed up the design verification process, computer aided simulations are used to perform motion analysis of the proposed IPMC actuated mechanism through Pro/Mechanism tool. Inverse kinematic analysis is performed to find out the joint variables of the mechanism to realize fin actuation along desired path. Displacements, velocities and accelerations of the links constructing mechanism are found out to establish their interrelationship. Results are analysed for the study of mechanism efficacy and for sizing the IPMC actuators. This paper contributes to introduce a new approach of virtual prototyping using advanced simulation tools for analysis and design verification of IPMC actuated mechanisms for biomimetic applications before moving into functional prototype stage.

Dynamic Analysis of IPMC Actuated Fin of a Micro Fish Like Device

In this paper, a methodology is presented to perform dynamic analysis of structural linked mechanisms under true actuation cycle and force response of applied IPMC actuators. Dynamic analysis of a three link mechanism for fin actuation of a micro fish like device, towed by a surface vessel through tow cable, is performed through this methodology and same is applicable to other biomimetic robotic applications. Fluid (water) exerts a torque on IPMC actuated fin which is a function of fins deflection and fluid flow velocity. Dynamic analysis is performed to assess the performance and efficacy of fin actuation mechanism under different loading conditions in terms of fins deflection, velocity and acceleration. Actuation force is increased by increasing number of applied IPMC actuators of known actuation cycle and force generation response. Applied torque is determined by performing a numerical simulation of IPMC actuated fin against different flow velocities through two-way fluid structure interaction (FSI) approach. Numerical simulation is performed in ANSYS WORKBENCH to capture the complex hydrodynamic interactions between fin and fluid. Effect of increased actuation force against constant flow velocity (towing speed) and of increased flow velocity against constant actuation force are evaluated in terms of fins deflection, velocity and acceleration. Finally, consequence of increasing the length of the link, connecting IPMC actuators and fin, are appraised for same actuation force and applied torque. Dynamic analysis is performed in Pro/ Mechanism, an advanced simulation tool. A technique of virtual prototyping through simulations is applied to access the performance of the fin actuation mechanism under true loading scenario before going into experimental phase, saving cost and time

Forward Kinematic Analysis of IPMC Actuated Three Link Mechanism for Fin Actuation of Fish Like Micro Device

IPMC is becoming an increasingly popular material among scholars, engineers and scientists due to its inherent properties of low activation voltage, large bending strain, flexibility, softness, suitable response time which make them a strong candidate to be applied as artificial muscle in biomimetic land and underwater applications. The applications of IPMC have been growing due to progression in its manufacturing techniques, development of more accurate response models and control techniques, and recently more sophisticated IPMC actuator applications have been performed. In this paper, a new application of IPMC is proposed to actuate aileron fins of a micro scanning device towed underwater by a surface vessel to control its depth and to stabilize it against roll motion that can mimic pectoral fins of fish that steer them up and down by changing their angle of rotation and their dorsal fins that keep them upright against roll. Same is applicable for autonomous underwater vehicles. Secondly, a three link mechanism is presented to actuate aileron fin through IPMC actuator. Three dimensional model of the mechanism is developed in Pro-Engineer CAD software tool and its kinematic analysis is performed. Thirdly, forward kinematic model of proposed mechanism, based on geometric coordinate, is presented. Lastly, results of kinematic analysis of proposed mechanism are compared to that of model to verify its design and kinematics. Encouraging results decoy the research team to manufacture the mechanism and to perform experiments for its practical application.

A Comprehensive Review of the Biomimetic Applications of Ionic Polymer Metal Composite

Bio-inspiration focuses on translating the evolutionary successes of natural species into engineering systems that mimic the geometry, function, and performance of the natural system. In this paper we present a latest comprehensive review of ionic polymer metal composite (IPMC) biomedical and biomimetic applications. IPMC is becoming an increasingly popular material among scholars, engineers and scientists due to its inherent properties of low activation voltage, large bending strain, flexibility, softness, suitable response time which make them a strong candidate to be applied as artificial muscle in biomimetic land and underwater applications. Among the diversity of electro active polymers (EAPs), recently developed IPMCs are good candidates for use in bio-related application because of their biocompatibility. Several recently reported IPMC biomimetic applications have been reported in this paper. The applications of IPMC have been growing due to progression in its manufacturing techniques, development of more accurate response models and control techniques, and recently more sophisticated IPMC actuator applications have been performed. This indicates that the IPMC actuators hold potential for more sophisticated and controlled applications in fields of biomedical and biomimetic. Extensive references are provided for more indepth explanation.

Design Improvement of Assembly Workplace through Ergonomic Simulation and Analysis Using DELMIA

The aim of this research is to demonstrate the ergonomic process modeling and simulation of manual assembly work through virtual assembly approach in order to present workplace and process improvement prior to their physical prototyping. In this regard, a case study has been carried out to analyze an assembly workplace of a diesel engine by ergonomics simulation and virtual assembly approach. DELMIA, a software tool, has been exploited for the ergonomic simulation and analysis in virtual assembly environment. The case study demonstrates several improvements in the ergonomics of the operators performing assembly on production line of the diesel engine. The assembly process of last few stations of the diesel engine simulated and analyzed on DELMIA in order to exhibit the advantages of the virtual assembly approach to the workplace deign and saving of process time and energy expenditure of operator. On last station of the engine assembly line, parts are assembled relatively at higher and complex positions and it is difficult for an operator to assembly them. Since, the assembly is carried out on conveyor; it is not convenient to change the height of conveyor to overcome the problem. Therefore, height of the floor of last work station is altered / increased. In order to achieve the increased floor height, a number of benches of variable heights are placed on the floor on the last working station one by one in the simulation environment and simulation of the process is carried out. The simulation results show that the ergonomics of operators have significantly changed by altering working height of the operator. Simulation of second last and other working station has also been performed by altering the height of the floor, but no improvements in the ergonomics of the operator observed for these stations

Torque Analysis of IPMC Actuated Fin of a Micro Fish like Device Using Two-Way Fluid Structure Interaction Approach

In this paper, a numerical simulation of three dimensional model of IPMC actuated fin of a fish like micro device is presented using two-way fluid structure interaction approach. The device is towed by the surface vessel through a tow cable. Fin is acting as dorsal fin of the fish to control depth of the device and also acts as a stabiliser against its roll motion. Fins displacement disturbs water flow streamlines around it, as a result velocity and pressure profile of fluids domain changes around the actuated fin. As fins position continuously changes throughout its actuation cycle, this makes it transient structural problem coupled with a fluid domain. Fins displacement is received by the fluid and resulting fluid forces are received by the fin making it a two-way fluid structure interaction (FSI) problem. Such problems are solved by multi field numerical simulation approach. This multifield numerical simulation is performed in ANSYS WORKBENCH by coupling transient structural and Fluid Flow (CFX) analysis systems. It is desirous to determine the torque acting on the fin due to fluid forces through its actuation cycle by IPMC actuators. The objective of this study is to develop the methodology (two-way fluid structural interaction (FSI)) used to simulate the transient FSI response of the IPMC actuated fin, subjected to large displacement against different flow speeds. Efficacy of fin as depressor and riser is also required to be judged by monitoring the forces acting on wing in response to its displacement under IPMC actuation. Same approach is also applicable to the self-propelled systems.

Deflection Analysis of IPMC Actuated Fin of a Fish Like Micro Device

IPMC is used as artificial muscle in bioinspired micro structures/devices due to its low voltage actuation, high bending deformation, rapid response and capability to be operated in aqueous environment. In this paper, deflection analysis of IPMC actuated fin of a micro fish like device is presented to find out angle of attacks generated by IPMC deflection under different voltages applied to it. A novel approach is presented to perform motion analysis of IPMC actuated mechanisms for biomimetic robots under true actuation presentation of the IPMC actuator. This paper also contributes to present velocity and acceleration of the actuator at different voltages. Finally, two different configurations of the fin actuation mechanism are characterized in terms of angle of attack produced by them under same actuation responses of an IPMC actuator. Deflection analysis is performed in Pro/ Mechanism, an advanced simulation tool. A technique of virtual prototyping through simulations is applied to access the performance of both configurations of the fin actuation mechanism under true scenario before going into manufacturing.

Force Analysis of IPMC Actuated Fin and Wing Assembly of a Micro Scanning Device through Two-Way Fluid Structure Interaction Approach

In this paper, a methodology is presented to perform force analysis of wing and fin assembly of a micro fish like device through strongly coupled two-way fluid structure interaction approach. The scanning device operates underwater and is towed by a surface vessel through a tow cable. Device fins are actuated by ionic polymer metal composite (IPMC) actuators, an EAP actuator. Fins act as riser, depressor and stabiliser against roll motion of the device. During tow, wing and fin assembly of the device come under hydrodynamic forces. These forces are influenced by fin displacement under IPMC actuation and wings angle of attack for same towing conditions. To fully investigate wing and fin assembly performance, we must consider the interaction between their structure and fluid (water) and model the coupling mechanism accurately for fluid structure interaction (FSI) analysis. To obtain an accurate prediction to the hydrodynamic forces on wing and fin assembly of the device, it is necessary to conduct dynamic analysis of the surrounding fluid by computational fluid dynamics (CFD). A numerical simulation of three dimensional model of the assembly is performed in ANSYS WORKBENCH by coupling transient structural and Fluid Flow (CFX) analysis systems. The objectives of this study are as follows: 1) To build an accurate three-dimensional CFD model of the wing and IPMC actuated fin 2) To quantify the lift and drag forces acting on the wing and their corresponding coefficients 3) To demonstrate the influence of wings angle of attack and fin displacement on generation of lift and drag forces. The presented methodology is also applicable to self-propelled micro robots.