Debanik Roy

Study on the Configuration Space Based Algorithmic Path Planning of Industrial Robots in an Unstructured Congested Three-Dimensional Space: An Approach Using Visibility Map

Obstacle avoidance and subsequently collision-free path planning is a potential field of robotics research, specially in the perspective of todays industrial scenario. In this paper, the celebrated method, namely, Visibility Map is being used to generate feasible collision-free near-optimal safe path(s) for a three- dimensional congested robot workspace using heuristic algorithms. The final path is obtainable in terms of joint configurations, by considering the Configuration Space of the task-space. The developed algorithms have been verified by considering typical 2D workspaces at the onset, cluttered with different obstacles (convex and/or concave) with regular geometries and later on, with the real spatial manifold. The outcome of these algorithms has been found instrumental in programming an industrial robot in order to perform a series of task in the shop-floor. A case-study reveals the effectiveness of the heuristics involved in the developed algorithms, by virtue of the successful application in an unstructured industrial environment to carry out robotized material handling operation in real-time.

Estimation of Grip Force and Slip Behavior During Robotic Grasp Using Data Fusion and Hypothesis Testing: Case Study with a Matrix Sensor

Algorithmic data fusion for multi-sensory system becomes extremely challenging, particularly where the elemental sensory units do vary in type, size and characteristics. Although traditional theories on sensory data fusion fit quite satisfactorily in searching a pre-defined object with a tentative dimension and depth perception, they fail to do justice in cases where profile of the object do vary from a point-mass to a finite spatial dimension. The present paper dwells on modeling, algorithm and experimental analysis of two novel fusion rule-bases, which are implemented in a small-sized tactile array sensor to be used in robot gripper. A new proposition has also been developed for assessing the decision threshold, signaling the presence of object inside the grasp-zone of the gripper. Besides, the developed model evaluates the approximate planar area of the grasped object alongwith its shape in real-time. The model also provides estimate for the gripping force required to sustain a stable grasp of the object vis-à-vis slippage characteristics, if any.

Development and Model-Aided Performance Measure of a Sensor-Augmented Industrial Robotic System for Handling Steel Bearing Races in an Unstructured Environment

Abstract Industrial application of robotic system for material handling operations has progressively become more challenging in situations of unstructured environments, in comparison to the same under somewhat known perspectives. Gripping under an unstructured robotic workspace poses serious challenges, which are beyond the purview of traditional grasp models and those need to be tackled only through customized modeling of the robotic environment. The present paper describes the details of such an application at the shop-floor of TATA STEEL, India, encompassing installation of the four degrees-of-freedom SCARA type industrial robotic system, design and construction of the magnetic gripper, sensory and hardware interfaces, safety measures (viz. design and development of electronic guarding system), environment model, application programming and final commissioning of the system for the intended use of handling steel bearing races of various sizes. Besides technical paradigms, the paper focuses on the performance measure of this maiden application of robotics in Indian steel industries.

Design and Developmental Metrics of a `Skin-Like' Multi-Input Quasi-Compliant Robotic Gripper Sensor Using Tactile Matrix

Slip-resistant robust grasping of objects during remote manipulation remains one of the major open issues in robotics. Finer measurement of tangential force and slippage need to be considered for the task planning and control of robotic gripper in operation. Design and development of such a multi-sensory tactile array is reported in this paper, which is aimed for direct use in an instrumented jaw intelligent robot gripper for potentially hazardous radioactive environments. A new design has been reported in the paper, wherein sensing members of the prototype follow a combination of beam (bending) and truss-type (axial deformation) behavior under external loadings. Various characteristics of the sensor, viz. condition number, static and dynamic stiffness, sensitivity and repeatability have been evaluated, based on the results from field trials of the prototype. Besides the comparatively larger prototype, a miniaturized version of the sensor has also been developed and tested for object grasping in real-time.

Stochastic model-based grasp synthesis: New logistics for data fusion with dissimilar sensor-cells

We attribute the data fusion logistics with dissimilar sensor-cells (taxels) an open-research paradigm, because the in-built characteristics in quantifying the system (output) response is still fuzzy. The problem gets even critical when we are bound to deal with a finite number of elemental taxels, as against traditional theories catering to somewhat denser agglomeration of (identical) sensor units. In fact, fusion models used hitherto have been found to be largely inappropriate for some of the distinct object-groups, e.g. from point-mass to small-sized ones. Besides, metrics of grasp synthesis (grip force & slippage) were largely unattended. In answering those lacunas, the present paper dwells on the modeling, algorithm and theoretical analysis of a novel fusion rule-base, centering on the relative dependency of the finite numbered taxels. A new proposition has also been developed for assessing the decision threshold-band, signaling the presence of object inside the grasp-zone of the gripper.

A Distributed Generic Architecture for User-Interactive Internet-Based Remote Activation Towards Manoeuvring Mechatronic Systems in Tandem

Module-intensive user-interactive technology towards developing Internet-based communication has become instrumental in implementing actuation sequences of a remotely located mechatronic device. Bi-directional data communication metrics, hitherto dominated largely by text-based formats, has attained substantial up-gradation whereby global access vis-à-vis exchange of technical data has become a boon for the Internet users at large. However, presence of a common web-server in the communication loop has been indispensable till date. The present work reports a novel technique, whereby the web-server is bypassed and the web-enability is ensured by means of peer-to-peer socket communication between the client and the host in situ. The paper delineates algorithm of a new protocol and developmental semantics of the end-hardware for web-enabled communication in order to successfully orchestrate various domains of traditional client–server handshaking in a meaningful and synergistic manner. The developed protocol encompasses programming semantics of web-enabled applets, formulation logistics and portability issues over the Internet. The paper presents the real-life testing sequences for remote activation of a table-top robotic manipulator successively in a Local Area Network (LAN) and also in a Wide Area Network (WAN) and finally through the Internet, using a dedicated web-site.

Development and model‐aided performance measure of a sensor‐augmented industrial robotic system for handling steel bearing races in an unstructured environment

Purpose – Aims to measure the development and performance of a sensor‐augmented industrial robotic system for handling steel bearing races in an unstructured environment.Design/methodology/approach – Performs exhaustive experimentation during installation of the robotic system to assess its performance capability in terms of average lifting capacity and cycle time of operation.Findings – Reveals that improvement can be achieved without damping, though rubber padding still appears to be useful sometimes in higher speed operations. Also unloading operations appear to cause more trouble than loading.Practical implications – The introduction of the robotic system will culminate in lower cycle time, increased productivity and optimal utilization of the annealing furnace.Originality/value – Will be beneficial for those involved in material handling operations in an unstructured environment as opposed to more familiar conditions.

A new fusion rule with dynamic decision threshold for heterogeneous field gripper sensory system: Part II

Rule-based data fusion for heterogeneous field sensory system is a challenging research paradigm till date, primarily due to the inherent characteristics in quantifying the output response of the system. The problem gets even critical when we need to deal with a limited number of elemental sensor-units in field, in contrast to traditional theories dealing with denser agglomeration of (identical) sensor units. In fact, field fusion models used hitherto have been found to be somewhat inappropriate for online detection of target-object(s), unless those are in a pre-assigned layout. Besides, the effect due to zonal distribution of the field-sensors was largely unattended. In answering those lacunas, the present paper dwells on the modeling, algorithm and theoretical analysis of a novel fusion rule-base, in its refined form, centering on the zone-based relative dependency of the finite numbered field sensor-units. Besides, a new proposition is developed for assessing the decision threshold-band, signaling the activation of the field robotic gripper, using a stochastic model.

Single Point Incremental Forming Using Flexible Die

Incremental sheet forming is an innovative process having ability to fulfill demands for customized sheet metal parts without using costly dies unlike traditional forming processes. However, shape deviation of formed parts is one of the drawbacks which need technological developments to use ISF on shop floor. Backdrawing, use of half dies and customized toolpaths are some of the techniques being worked out for reducing shape deviation but have some limitations. The present work investigates the flexible die developed to reduce shape deviation of the non-axisymmetric parts formed through SPIF. Experiments were carried out with different geometries to check the effectiveness of flexible die. Results show a significant improvement in the parts formed using flexible die over those formed without using it. This work gives another method for forming components with reduced bending. Also it proposes a new method of using bolts as flexible die which doesn’t needs to be changed with the part geometry.