Investigation on Robotic Grasping and Manipulation: An Analytical and Experimental Approach

Abstract

Robots are employed in the manufacturing plants for the manufacturing of high-quality products and for having a high production rate. Robot grasping and manipulation is an active research area for several decades. Although significant research works are done, stable robotic grasping and manipulation is still a challenging problem. Automatic robotic grasping is a broad area with complicated and challenging tasks to fulfil that includes grasp planning, analysis, grasp synthesis, optimal grasp planning, grasp stability analysis, development of grasp control algorithm, obstacle avoidance, and design of robotic hand, among others. In this research work, an investigation is carried out to study robotic grasping and manipulation using both analytical and experimental approaches. The analytical approach that used the grasp planning and synthesis methods to find the appropriate strategy for grasping the objects. Grasp planning and synthesis are used in grasping and manipulation to find the stable grasp configuration by locating the position of the fingertip of the robotic hand to be placed on the objects. The stability of the robotic grasp is measured in terms of grasp quality measures, which is a mathematical quantification to measure the grasp quality. An evolutionary approach is proposed to enhance the grasp quality measures, so that the obtained robotic grasp achieves stability without any failure. The proposed evolutionary algorithm evaluates the automated robotic grasp planning and manipulation problem as a maximizing problem to enhance the grasp quality. The grasp planning problem is addressed by incorporating the uncertainty in the coefficient of friction while modelling the contact model between fingertips and objects. The proposed model that includes the uncertainty associated with the friction coefficient is handled by an interval arithmetic approach. The experimental approach of robotic grasping and manipulation is carried out for handling objects with different shapes, weights, and sizes, and that can be achieved by the development of a multi-finger robotic hand with adaptive nature to hold a variety of objects. A systematic approach is introduced by using the V-design approach to find a suitable design that fulfils the required design solution by evaluating all the possible scenarios to meet the functional requirements like speed as well as flexibility while grasping the objects. The bio-inspired design approach is adopted to fulfil the design goals (human-robot interaction, robot-environment interaction) and design requirements (efficiency, safety, robustness, adaptivity, control simplicity, and natural motion) through the integration of rigid and soft materials similar to bone and skin of the human hand. The joints of the robotic hands are developed from the inspiration taken from hydraulic joints of spider legs. The mechanics of the proposed robotic hand is fabricated using soft and rigid materials and are investigated with the help of lie algebra, screw theory, and cosserat based approach. The optimal design of the robotic hand is investigated using a proposed evolutionary meta-heuristics method. A case study of the optimal design study is conducted considering three standard parallel gripper configuration to validate the efficiency of the proposed evolutionary algorithm. Then the optimal design study of the proposed robotic hand is carried out considering a single robotic finger as all the robotic fingers are equivalent. The uncertainties associated with kinematic parameters, material properties, and joint inputs of the proposed design are investigated using the affine arithmetic approach. An elaborated study is conducted to characterize the material properties for both rigid (ABS, PLA), flexible (TPU) and soft materials (Ecoflex 00-10, 00-30, 00-50, and Dragonskin 30) used to develop the prototype of the hybrid robotic hand. A tendon driven mechanism is used to actuate the proposed robotic hand, and the soft joints of each finger are operated with pneumatic pressure to perform the in-hand manipulation operations. It is essential to find out the different performance metrics of the developed robotic finger such as finger strength, grasp strength, grasp cycle time, grasp efficiency, slip resistance, and in-hand manipulations. All the above performance metrics are evaluated to find the efficiency of the proposed robot hand. Finally, experimentation is conducted on a variety of objects used in daily life.