Divyanshu Goel

Bio: Divyanshu Goel is an academic researcher from International Institute of Information Technology, Hyderabad. The author has contributed to research in topics: Force-sensing resistor & Articulated robot. The author has an hindex of 2, co-authored 2 publications receiving 7 citations.

Implementation of gaits for achieving omnidirectional walking in a quadruped robot

Abstract: In this paper, we propose a better planning technique of the standard walking gaits for a quadruped robot than the conventional successive gait transition method to realize omnidirectional static walking. The technique involved planning the sequence as well as motion of the swinging and supporting legs. The relationship between the stability margin, the stride length and the duty factor are also formulated mathematically. The proposed modified crawl gait is compared to the conventional method with respect to the above parameters geometrically as well as mathematically and is shown to have positive stability margin at all times. The successive gait transition is demonstrated on the modified crawl and rotation gaits. Computer simulations of a model quadruped robot were performed to validate the theory proposed. Experiments were performed on an actual quadruped robot to realize the omnidirectional static walking with increased stability margin.

Design and development of a humanoid with articulated torso

Abstract: The purpose of this paper is to present the model of a Humanoid robot inspired by Poppy, modified for heavier load capacity and the balancing of humanoid in multiple work environments. The design has been modified in order to use MX-64 servos with more torque capacity than MX-28 servos which were used in original design. We have also redesigned the ankle joint and feet to make it a more accurate human like model. We are using an integrated approach using zero moment point (ZMP) with force sensing resistor (FSR) and center of mass (CoM) to find balance margins of the robot. Balancing and forward bending experiments on robot are conducted by providing some basic motion to the robot and ensuring that the robot is balanced and moving within safe margins using this approach.

Quadruped robot control method and control device on the basis of sine opposite angle gait and quick table look-up method

Abstract: The invention relates to a quadruped robot control method and control device on the basis of a sine opposite angle gait and a quick table look-up method. The method comprises the following steps that: (1) combining with the opposite angle gait to analyze the leg structure of a quadruped robot, establishing the leg movement mathematical model of the quadruped robot, and adopting a novel sine gait; (2) solving a nonlinear equation set to obtain the control rate of each joint of four limbs, establishing a database which specially faces robot movement control, obtaining an accurate joint opening and closing angle through the quick table look-up method, and quickly and accurately realizing foot end trajectory control; and (3) designing a foot end trajectory control unit and a steering control unit so as to bring convenience to the access of other control systems. On an aspect of trafficability characteristics, the novel sine gait is designed and adopted, and therefore, and the robot owns high trafficability when the robot faces a complex terrain. On the aspect of operation stability, when a step taking period stops, the horizontal speed of a swing phase is zero, and therefore, the method is high in stability. The table look-up method is adopted to quickly, accurately and stably carry out the foot end trajectory control.

Quadruped Robot Creeping Gait Stability Analysis and Optimization Using PSO

Abstract: The potential ability of the quadruped (four-legged) robot locomotion has been used for many different applications such as walking over soft and rough terrains. These applications are needed to grantee the mobility and flexibility. Generally, quadruped robots have three main periodic gaits: creeping gait, running gait and galloping gait. The stability criteria is the main problem of the quadruped robot during walking with a slow motion gait such as creeping gait. The static stability gait is completely depends on the stability margins during the walking which have been calculated in this paper. The quadruped robot kinematic model of the forward and inverse kinematics for each 3-DOF leg has been calculated which leading to find the minimum stability margins during walking on the vertical geometrical projection of the robot body. These margins are needed to be optimized for achieving the best stability margin during the robot walking.in this paper we using the PSO optimization algorithm to find the best value of the stability margin. Simulation and results verify the stability margin range values and the optimized results.

Creeping Gait Analysis and Simulation of a Quadruped Robot

Abstract: الكوادروبيد ربوت هو روبوت رباعي الارجل له القابلية على القيام بمهمات عديدة منها المشي والانتقال على الارض المسطحة فضلا عن قدرته على المشي على الارض الوعرة. يقوم هذا الروبت على محاكاة الحيوانات او الحشرات رباعية الارجل من خلال تقليد الحركات التي تقوم بها هذه الحيوانات. إن من أشهر الحركات التي يستخدمها هذا الروبوت في الانتقال هي: المشي والركض والركض مع القفز. ان حركة المشي التي تم تنفيذها في هذه الورقة هي عبارة عن تحريك رجل واحدة بعد الاخرى خلال مدة زمنية معينة وبعد وصول الرجل الى المكان المناسب تبدأ رجل اخرى بالحركة. يستخدم هذا الايقاع في الحركة لكي نضمن بقاء ثلاثة أرجل ملتصقة على الارض لتحقيق الاستقرارية خلال مدة انتقال الرجل المرفوعة. خلال عملية رفع احدى الارجل سوف يتكون مثلث ناتج من اسقاط نقاط تثبيت بقية الارجل الثلاث مع سنتر الروبوت على الارض.ان مهمة هذا الروبوت هو البقاء مستقرا خلال هذه الحركات لذلك يحتاج الى تحليل الاستقرارية عن طريق حساب الـ (Stability Margins) في هذه الورقة ايضا تم تحليل حركة الروبوت بالنسبة للمشي البطيء(Creeping Gait) ومن ثم حساب معادلات الكاينماتيك الخاصة للحصول على موقع الارجل على الارض واللازمة لتحقيق الاستقرارية الثابتة للروبوت اثناء المشي. ومن بعدها تم الحصول على النتائج اللازمة لتحقيق هذه الاستقرارية من خلال مواقع الارجل على الارض.

Comparative Study Between Classical and Optimized Stability Margins of Quadruped Robot Creeping Gait

Abstract: The ability of the quadruped (four-legged) robot locomotion was used in a lot of different applications like walking over soft and rough terrains. These applications needed to guarantee the flexibility and mobility. Generally, quadruped robots have three basic periodic gaits: creeping gait, running gait and galloping gait. The stability criteria are the main issue of the quadruped robot throughout walking with the slow motion gait like creeping gait. The gait of static stability is completely bases on the stability margins in the walking that was calculated in this paper. The quadruped robot legs walking sequence and creeping gait within the leg fixing and swinging phases carried out. The kinematics model of quadruped robot of the forward and inverse kinematics for each leg 3-DOF was calculated that lead to discover the minimum stability margins with walking on the vertical projection of the robot geometrical body. These stability margins needed to be optimized in order to obtain the best stability margin throughout this robot walking. In this paper we use the PSO optimization algorithm to get the best stability margins value. Simulation and results are verified the range of the stability margin values and the optimized results.

Learning Dual Arm Coordinated Reachability Tasks in a Humanoid Robot with Articulated Torso

Abstract: Performing dual arm coordinated (reachability)tasks in humanoid robots require complex planning strategies and this complexity increases further, in case of humanoids with articulated torso. These complex strategies may not be suitable for online motion planning. This paper proposes a faster way to accomplish dual arm coordinated tasks using methodology based on Reinforcement Learning. The contribution of this paper is twofold. Firstly, we propose DiGrad (Differential Gradients), a new RL framework for multi-task learning in manipulators. Secondly, we show how this framework can be adopted to learn dual arm coordination in a 27 degrees of freedom (DOF)humanoid robot with articulated spine. The proposed framework and methodology are evaluated in various environments and simulation results are presented. A comparative study of DiGrad with its parent algorithm in different settings is also presented.