Design and Development of the Cassino Biped Locomotor

2020 ◽  
Vol 12 (3) ◽  
Author(s):  
Mingfeng Wang ◽  
Marco Ceccarelli ◽  
Giuseppe Carbone
Keyword(s):  
Inverse Kinematics ◽  
Low Cost ◽  
Parallel Mechanisms ◽  
Operation Performance ◽  
Gait Planning ◽  
Biped Walking Robot ◽  
Structural Parts ◽  
Three Degree Of Freedom ◽  
Leg Design

Abstract In this work, the Cassino Biped Locomotor, a biped walking robot, is presented as the leg design by using reduced parallel mechanisms. The proposed biped locomotor consists of two identical tripod leg mechanisms with a three degree-of-freedom parallel manipulator architecture. Kinematics analysis is carried out in terms of the forward and inverse kinematics of one leg mechanism and inverse kinematics of the biped locomotor. The walking operation is discussed in detail with gait planning and trajectories of feet and waist. A CAD model is elaborated in solidworks® environment and the corresponding prototype is fabricated with low-cost user-oriented features by using commercial components and structural parts that are manufactured by using 3D printing. An experimental layout and corresponding test modes are illustrated for characterizing the walking operation performance. Experimental results are analyzed for an operation performance evaluation and architecture design characterization of the Cassino Biped Locomotor.

scholarly journals An Experimental Characterization of TORVEastro, Cable-Driven Astronaut Robot

Robotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 21
Author(s):  
Francesco Samani ◽  
Marco Ceccarelli
Keyword(s):  
Mechanical Design ◽  
Vision System ◽  
Service Robot ◽  
Test Results ◽  
Operation Performance ◽  
Space Applications ◽  
Outdoor Space ◽  
Motion Characteristics ◽  
Three Degree Of Freedom

TORVEastro robot design is presented with a built prototype in LARM2 (Laboratory of Robot Mechatronics) for testing and characterizing its functionality for service in space stations. Several robot astronauts are designed with bulky human-like structures that cannot be convenient for outdoor space service in monitoring and maintenance of the external structures of orbital stations. The design features of TORVEastro robot are discussed with its peculiar mechanical design with 3 arm-legs as agile service robot astronaut. A lab prototype is used to test the operation performance and the feasibility of its peculiar design. The robot weighs 1 kg, and consists of a central torso, three identical three-degree of freedom (DoF) arm–legs and one vision system. Test results are reported to discuss the operation efficiency in terms of motion characteristics and power consumption during lab experiments that nevertheless show the feasibility of the robot for outdoor space applications.

Design and Research of a Walking Robot with Two Parallel Mechanisms

Robotica ◽  
2021 ◽  
pp. 1-8
Author(s):  
Huanhuan Ren ◽  
Lizhong Zhang ◽  
Chengzhi Su
Keyword(s):  
Inverse Kinematics ◽  
Biped Robot ◽  
Structural Features ◽  
Upper Body ◽  
Parallel Mechanisms ◽  
Walking Robot ◽  
Gait Planning ◽  
New Type ◽  
Special Case ◽  
Moving Speed

SUMMARY In this paper, a new type of biped mobile robot is designed. Each leg of the robot is a 6 degree-of-freedom (DOF) parallel mechanism, and each leg has three relatively fixed landing points. The leg’s structure gives the robot better performance on large carrying capacity, strong environmental adaptability and fast moving speed simultaneously. At the same time, it helps the robot move more steadily and change direction more simply. Based on the structural features of the leg, the inverse kinematics model of the biped robot is established and a unified formula is obtained. According to an analysis of robot’s workspace, gait planning is completed and simulated. Finally, the special case that the robot can keep the upper body horizontal while walking on a slopy surface is validated.

A New Design for Cassino Hexapod Robot

2010 ◽  
Author(s):  
Nestor Eduardo Nava Rodri´guez ◽  
Luis Moreno Lorente ◽  
Giuseppe Carbone ◽  
Marco Ceccarelli
Keyword(s):  
Degrees Of Freedom ◽  
Low Cost ◽  
Past Research ◽  
Hexapod Robot ◽  
Logic Device ◽  
Operation Performance ◽  
Research Activities ◽  
Leg Design ◽  
Pitch Movement ◽  
Three Degrees Of Freedom

We present the design process of a new low-cost easy-operation Cassino Hexapod robot. In a recent past, research activities have been carried out for developing a six-legged robot at LARM (LAboratory of Robotics and Mechatronics) of Cassino University in Italy. The robot designs have been based on suitable mechanism structures and architectures that can be easy operated by a commercial on-off logic device. The first prototype is composed of modular legs with three degrees of freedom (DOF). A second prototype of a hexapod leg presents two links and two DOFs. The new prototype Cassino Hexapod robot has two DOFs, such as, one for pitch movement that drives an articulated mechanism and other for yaw movement. Additional peculiarity of the leg design is that the foot is designed as a powered wheel with the possibility to regulate the velocity and force at the contact during the support phases of the leg. Simulation results of the proposed design operation of the new hexapod robot are reported with the aim of characterizing both operation performance and design features.

scholarly journals Microstructure and Thermoelectric Properties of (Bi0.48Sb1.52)Te3 Thick Films Prepared with Tape Casting Method

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 140
Author(s):  
Lichen Liu ◽  
Ziping Cao ◽  
Min Chen ◽  
Jun Jiang
Keyword(s):  
Thermoelectric Properties ◽  
Low Cost ◽  
Thick Films ◽  
Tape Casting ◽  
Casting Process ◽  
Casting Method ◽  
Glass Substrates ◽  
Conductive Films ◽  
Casting Technology

This paper reports the fabrication and characterization of (Bi0.48Sb1.52)Te3 thick films using a tape casting process on glass substrates. A slurry of thermoelectric (Bi0.48Sb1.52)Te3 was developed and cured thick films were annealed in a vacuum chamber at 500–600 °C. The microstructure of these films was analyzed, and the Seebeck coefficient and electric conductivity were tested. It was found that the subsequent annealing process must be carefully designed to achieve good thermoelectric properties of these samples. Conductive films were obtained after annealing and led to acceptable thermoelectric performance. While the properties of these initial materials are not at the level of bulk materials, this work demonstrates that the low-cost tape casting technology is promising for fabricating thermoelectric modules for energy conversion.

scholarly journals Optimized stable gait planning of biped robot using multi-objective evolutionary JAYA algorithm

2020 ◽  
Vol 17 (6) ◽  
pp. 172988142097634
Author(s):  
Huan Tran Thien ◽  
Cao Van Kien ◽  
Ho Pham Huy Anh
Keyword(s):  
Inverse Kinematics ◽  
Biped Robot ◽  
Step Length ◽  
Jaya Algorithm ◽  
Kinetic Chain ◽  
Biped Walking ◽  
Gait Planning ◽  
Multi Objective ◽  
Simulation And Experiment ◽  
Stable Gait

This article proposes a new stable biped walking pattern generator with preset step-length value, optimized by multi-objective JAYA algorithm. The biped robot is modeled as a kinetic chain of 11 links connected by 10 joints. The inverse kinematics of the biped is applied to derive the specified biped hip and feet positions. The two objectives related to the biped walking stability and the biped to follow the preset step-length magnitude have been fully investigated and Pareto optimal front of solutions has been acquired. To demonstrate the effectiveness and superiority of proposed multi-objective JAYA, the results are compared to those of MO-PSO and MO-NSGA-2 optimization approaches. The simulation and experiment results investigated over the real small-scaled biped HUBOT-4 assert that the multi-objective JAYA technique ensures an outperforming effective and stable gait planning and walking for biped with accurate preset step-length value.

scholarly journals Theoretical and Empirical Characterization of Water as a Factor: Examples and Related Issues with the World Trade Model

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 459
Author(s):  
Ignacio Cazcarro ◽  
Albert E. Steenge
Keyword(s):  
World Trade ◽  
Low Cost ◽  
Virtual Water ◽  
Considerable Change ◽  
Water Research ◽  
Trade Model ◽  
The World ◽  
Main Model ◽  
Selection Of

This article originates from the theoretical and empirical characterization of factors in the World Trade Model (WTM). It first illustrates the usefulness of this type of model for water research to address policy questions related to virtual water trade, water constraints and water scarcity. It also illustrates the importance of certain key decisions regarding the heterogeneity of water and its relation to the technologies being employed and the prices obtained. With regard to WTM, the global economic input–output model in which multiple technologies can produce a “homogeneous output”, it was recently shown that two different mechanisms should be distinguished by which multiple technologies can arise, i.e., from “technology-specific” or from “shared” factors, which implies a mechanism-specific set of prices, quantities and rents. We discuss and extend these characterizations, notably in relation to the real-world characterization of water as a factor (for which we use the terms technology specific, fully shared and “mixed”). We propose that the presence of these separate mechanisms results in the models being sensitive to relatively small variations in specific numerical values. To address this sensitivity, we suggest a specific role for specific (sub)models or key choices to counter unrealistic model outcomes. To support our proposal we present a selection of simulations for aggregated world regions, and show how key results concerning quantities, prices and rents can be subject to considerable change depending on the precise definitions of resource endowments and the technology-specificity of the factors. For instance, depending on the adopted water heterogeneity level, outcomes can vary from relatively low-cost solutions to higher cost ones and can even reach infeasibility. In the main model discussed here (WTM) factor prices are exogenous, which also contributes to the overall numerical sensitivity of the model. All this affects to a large extent our interpretation of the water challenges, which preferably need to be assessed in integrated frameworks, to account for the main socioeconomic variables, technologies and resources.

scholarly journals Synthesis and Theoretical Investigation Using DFT of 2,3-Diphenylquinoxaline Derivatives for Electronic and Photovoltaic Effects

2021 ◽  
Author(s):  
Dorota Zając ◽  
Dariusz Przybylski ◽  
Jadwiga Sołoducho
Keyword(s):  
Solar Cells ◽  
Acrylic Acid ◽  
Organic Semiconductors ◽  
Organic Solar Cells ◽  
Molecular Design ◽  
Low Cost ◽  
Design Synthesis ◽  
Semiconducting Properties ◽  
Homo Lumo

AbstractDeveloping effective and low‐cost organic semiconductors is an opportunity for the development of organic solar cells (OPV). Herein, we report the molecular design, synthesis and characterization of two molecules with D–A–D–A configuration: 2-cyano-3-(5-(8-(3,4-ethylenodioxythiophen-5-yl)-2,3-diphenylquinoxalin-5-yl)thiophen-2-yl)acrylic acid (6) and 2-cyano-3-(5-(2,3-diphenyl-8-(thiophen-2-yl)quinoxalin-5-yl)thiophen-2-yl)acrylic acid (7). Moreover, we investigated the structural, theoretical and optical properties. The distribution of HOMO/LUMO orbitals and the values of the ionization potential indicate good semiconducting properties of the compounds and that they can be a bipolar material. Also, the optical study show good absorption in visible light (λabs 380–550 nm). We investigate the theoretical optoelectronic properties of obtained compounds as potential materials for solar cells.

Kinematics of a New High-Precision Three-Degree-of-Freedom Parallel Manipulator

2006 ◽  
Vol 129 (3) ◽  
pp. 320-325 ◽  
Author(s):  
Farhad Tahmasebi
Keyword(s):  
Power Dissipation ◽  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degree Of Freedom ◽  
Base Plane ◽  
Degree Polynomial ◽  
Payload Capacity ◽  
Half Angle ◽  
Three Degree Of Freedom ◽  
Direct Kinematics

Closed-form direct and inverse kinematics of a new three-degree-of-freedom (DOF) parallel manipulator with inextensible limbs and base-mounted actuators are presented. The manipulator has higher resolution and precision than the existing three-DOF mechanisms with extensible limbs. Since all of the manipulator actuators are base mounted, higher payload capacity, smaller actuator sizes, and lower power dissipation can be obtained. The manipulator is suitable for alignment applications where only tip, tilt, and piston motions are significant. The direct kinematics of the manipulator is reduced to solving an eighth-degree polynomial in the square of the tangent of the half-angle between one of the limbs and the base plane. Hence, there are at most 16 assembly configurations for the manipulator. In addition, it is shown that the 16 solutions are eight pairs of reflected configurations with respect to the base plane. Numerical examples for the direct and inverse kinematics of the manipulator are also presented.

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