Somajyoti Majumder

Hand Gesture Recognition Systems: A Survey

Gesture was the first mode of communication for the primitive cave men. Later on human civilization has developed the verbal communication very well. But still nonverbal communication has not lost its weightage. Such non – verbal communication are being used not only for the physically challenged people, but also for different applications in diversified areas, such as aviation, surveying, music direction etc. It is the best method to interact with the computer without using other peripheral devices, such as keyboard, mouse. Researchers around the world are actively engaged in development of robust and efficient gesture recognition system, more specially, hand gesture recognition system for various applications. The major steps associated with the hand gesture recognition system are; data acquisition, gesture modeling, feature extraction and hand gesture recognition. There are several sub-steps and methodologies associated with the above steps. Different researchers have followed different algorithm or sometimes have devised their own algorithm. The current research work reviews the work carried out in last twenty years and a brief comparison has been performed to analyze the difficulties encountered by these systems, as well as the limitation. Finally the desired characteristics of a robust and efficient hand gesture recognition system have been described. General Terms Hand gesture recognition, comparison

Two IPMC Fingers Based Micro Gripper For Handling

This paper presents the behavior of two finger based micro gripper which is made of Ionic Polymer Metal Composite (IPMC), an Electro Active Polymer (EAP). An IPMC shows great potential as high-displacement and light weight actuator. Low mass force generation capability is utilized for micro gripping in micro assembly. IPMC responds to low voltage in the range of 0-3V. The material contains an electrolyte which transport ions in response to an external electric field. IPMC actuation for micro gripping is produced by deflecting material according to bending moment theory. An external electric field generated by suitable RC circuit causes this deflection. It is found that an IPMC actuates from 1–5 seconds. The maximum jaw opening and closing position of micro gripper are found to be 5 mm and 0.5 mm respectively. The effect of tempearture, as observed, shows that the acceptable limit varies from 23.1°C to 30.4°C while an IPMC is in operation. An experimental proto type is developed for evaluation of performance.

Face recognition using multimodal biometric features

This paper presents a new multimodal biometric approach using face and periocular biometric. The available face recognition algorithm performance in presence of multiple variations such as illumination, pose, expression, occlusion and plastic surgery is not satisfactory. Also, periocular biometrics face problems in presence of spectacles, head angle, hair and expression. A method which can extract multiple feature information from a single source and can give a satisfactory performance even with less number of training images is desirable. Thus combining face and periocular data obtained from the same image may increase the performance of the recognition system. A detailed performance analysis of face recognition and periocular biometric using Gabor and LBP features is carried out. This is then compared with the proposed multimodal biometric feature extraction technique. The experimental results obtained using Muct and plastic surgery face database shows that the proposed multimodal biometric performs better than other face recognition and individual biometric methods.

Microassembly by an IPMC-based flexible 4-bar mechanism

A new design for a flexible 4-bar mechanism using ionic polymer metal composite (IPMC) for micropeg-in-hole assembly is proposed. In such assembly a peg is inserted into a hole by a flexible 4-bar mechanism. During assembly there exist both lateral and angular errors in the positioning of the peg. Due to this misalignment, the forces at the contact point between the peg and hole cause a change in the coupler path. In order to accommodate these forces, an IPMC-based microgripper is fitted at the center of the coupler in the flexible 4-bar and an IPMC patch is also attached on the coupler. The IPMC patch, when actuated, applies a moment on the coupler, thus changing its deflection. The objective of the design is to correct the deflection in the coupler path and also add compliance at the gripper during assembly. A model of the flexible 4-bar mechanism with an IPMC-based compliant gripper is made in Adams software. The simulation results show that the path of the flexible coupler can be controlled by activating the IPMC patch, while the misalignment during assembly is compensated by the IPMC microgripper. An IPMC-based flexible 4-bar mechanism was fabricated and experiments were carried out. The results prove that the path of the mechanism can be controlled and compliance can also be accommodated by the proposed mechanism during assembly.

Biomimetic Behavior of IPMC Using EMG Signal for Micro Robot

This paper presents the biomimetic behavior of an ionic polymer metal composite (IPMC) based artificial finger for micro robot which can be applicable in holding the object. In this work, IPMC based artificial finger is actuated by controlled electromyographic (EMG) signal. The EMG signal is taken from human index finger via EMG sensor. This signal is pre-amplified before transferring to IPMC for achieving the large bending behavior of IPMC. The biomimetic actuation behavior of IPMC is studied by movement of index finger muscles through long tendons. The stability analysis of EMG signal from human index finger is carried out by providing the proportional–integral–derivative (PID) control system. Experimentally, it is observed that IPMC finger can hold the micro component when IPMC finger is activated through EMG via human muscles and an IPMC based micro gripper is demonstrated.

Amphibian subterranean robot for mine exploration

Although many experimental and applied robotic research have been carried out to cater the need of planetary explorer to deep sea systems, yet the application of subterranean robotics in underground mine is very rare. Particularly robot with intervention capability after post flooding situation of underground mines has not been reported earlier. Design and development of an amphibian exploring robot capable of operation in constrained mine environment puts a tremendous challenge from both scientific and engineering perspective. The amphibian Subterranean Robotic explorer (SR) is capable of moving over fairly rough terrain, crawl over basin floor as well as can swim effortlessly. This paper presents the development aspects of an amphibian exploring robot. Several field trials have been carried out for performance testing of the system to ascertain its capability on dry land as well as under water.

A Solution to Inverse Kinematics Problem Using the Concept of Sampling Importance Resampling

The Inverse Kinematics (IK) problem requires solving the non-linear transcendental equations. It is not always possible to obtain a closed form solution. Besides, the existence of a unique solution or multiple solutions is an important issue. This paper therefore tries to solve the IK problem using the Sampling Importance Resampling (SIR) particle filter. Since the particle filter can represent multimodal belief, the proposed approach has the ability to find multiple solutions to the problem. Simulations were performed on a 6 degree of freedom PUMA-like manipulator. Results show that the method exhibits convergence within 3 iterations of filtering. Also, the present approach succeeds in finding multiple solutions, performs well near singularities and requires no initial estimate. The method is computationally efficient and can be applied to many other serial manipulators with multiple degrees of freedom.

Digital controller for attitude control of a rotary-winged flying robot in hover

This paper presents the design of digital controller for attitude control of a rotary-winged flying robot in hover. It describes the best digital implementation of continuous compensation from linear SISO controller to control the nonlinear dynamics of the aerial robot. Results with limits are given for attitude correction against reference attitudes, set for maintaining the hover. Experiments are carried out on Bergen Turbine Observer model, equipped with a NAV420CA INS and mounted on a test rig with bending flexibility in all axes.

Experimental characterizations of bimorph piezoelectric actuator for robotic assembly

Piezoelectric actuator is one of the most versatile types of smart actuators, extensively used in different industrial applications like robotics, microelectromechanical systems, micro-assembly, biological cell handling, self-assembly, and optical component handling in photonics. By applying potential to a piezoelectric actuator, it can produce micro level deflection with large force generation, very fast response, and long-term actuation as compared to other actuators. The design and analysis of the bimorph piezoelectric cantilever using proportional–integral controller are carried out where the bimorph piezoelectric actuator is used as an active actuator for providing the dexterous behavior during robotic assembly. Characterization of bimorph piezoelectric actuator carried out by controlling voltage signal provides steady-state behavior which is verified by conducting experiments. A prototype of micro gripper is also developed which shows the potential of handling small lightweight objects for robotic assembly.

IPMC based micro gripper for miniature part handling

This paper presents the behavior of two finger based micro gripper which is made of Ionic Polymer Metal Composite (IPMC), an Electro Active Polymer. IPMC shows great potential as high-displacement and light weight actuator. Low mass force generation capability is utilized for micro gripping in micro assembly. IPMC responds to low voltage in the range of 0–3V. The material contains an electrolyte which transport ions in response to an external electric field. IPMC actuation for micro gripping is produced by deflecting material according to bending moment theory. An external electric field generated by suitable RC circuit causes this deflection. It is found that an IPMC actuates from 1–5 seconds. The maximum jaw opening and closing position of micro gripper are found to be 5 mm and 0.5 mm respectively.