A bio-inspired robotic climbing robot to understand kinematic and morphological determinants for an optimal climbing gait

Author(s):  
Hendrik Beck ◽  
Johanna J Schultz ◽  
Christofer J Clemente

Abstract Robotic systems for complex tasks, such as search and rescue or exploration, are limited for wheeled designs, thus the study of legged locomotion for robotic applications has become increasingly important. To successfully navigate in regions with rough terrain, a robot must not only be able to negotiate obstacles, but also climb steep inclines. Following the principles of biomimetics, we developed a modular bio-inspired climbing robot, named X4, which mimics the lizard’s bauplan including an actuated spine, shoulders, and feet which interlock with the surface via claws. We included the ability to modify gait and hardware parameters and simultaneously collect data with the robot’s sensors on climbed distance, slip occurrence and efficiency. We first explored the speed-stability trade-off and its interaction with limb swing phase dynamics, finding a sigmoidal pattern of limb movement resulted in the greatest distance travelled. By modifying foot orientation, we found two optima for both speed and stability, suggesting multiple stable configurations. We varied spine and limb range of motion, again showing two possible optimum configurations, and finally varied the centre of pro- and retraction on climbing performance, showing an advantage for protracted limbs during the stride. We then stacked optimal regions of performance and show that combining optimal dynamic patterns with either foot angles or ROM configurations have the greatest performance, but further optima stacking resulted in a decrease in performance, suggesting complex interactions between kinematic parameters. The search of optimal parameter configurations might not only be beneficial to improve robotic in-field operations but may also further the study of the locomotive evolution of climbing of animals, like lizards or insects.

2018 ◽  
Vol 249 ◽  
pp. 03005
Author(s):  
Xiang Zhang ◽  
Twan Capehart ◽  
Carl A. Moore

As people pay more attention to the safety of human-robotic interaction, the flexibility of machine joints is becoming more and more important. To address the needs of future robotic applications, many kinds of variable stiffness mechanisms have been designed by scientists. But most of the structures are complex. By studying and comparing many different mechanism designs of variable stiffness joint, we recognize the need to miniaturization and reduce weight of variable stiffness joints with high frequency operation. To address this, need a continuously Variable Compliant Joint (CVCJ) was designed. The core of the joint is based on the structure of the spherical continuously variable transmission (SCVT) which is the catalyst to change the stiffness continuously and smoothly. In this paper, we present a compact variable stiffness joint structure to meet the volume and weight requirements of the future robotic systems. We show the connection between the joint stiffness coefficient and the structure parameters by making mathematical analysis, modelling and simulation for the system to verify the ability to satisfy the base application requirements of the compliant joint.


2021 ◽  
Author(s):  
Simone Asci ◽  
Ketao Zhang

Abstract Among mobile robotic research field, legged locomotion is largely applied for advanced robotic systems due to the higher degree of versatility compared to wheeled robots, which allows them to successfully move and interact in unstructured environments; nevertheless, legged robots present several designing problems and require a much more complex control system. Based on an effective robotic leg, this paper presents a novel design, which integrates a cam joint, aimed to improve the versatility performances minimizing changes in the original model and without increasing the control complexity. Furthermore, the design strategy aims to exploit the coupled action of two actuators, which are disposed in a novel configuration so to gain versatility advantage while maintaining velocity performances of legs equipped with a single actuator. The model is presented through a kinematic analysis, followed by the simulation of the leg mechanism trajectory and a comparison with the original configuration.


1990 ◽  
Vol 112 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Kiyotaka Shimizu ◽  
Masakazu Suzuki ◽  
Misao Kato

This paper is concerned with a design method for optimizing dynamic compensators of Pearson’s type. Optimal parameter matrices are obtained by use of a parameter matching technique and an arbitrary pole placement technique. The controlled system has the optimal LQ modes and the modes with arbitrarily quick damping. The presented compensator works as the optimal regulator with observer and performs about the same control as the optimal regulator. And it is designed not in two steps; observer, regulator, but in one step; optimization of output feedback gain without considering any state estimation.


2011 ◽  
Vol 3 (3) ◽  
Author(s):  
Mark L. Guckert ◽  
Michael D. Naish

Spherical joints have evolved into a critical component of many robotic systems, often used to provide dexterity at the wrist of a manipulator. In this work, a novel 3 degree of freedom spherical joint is proposed, actuated by tendons that run along the surface of the sphere. The joint is mechanically simple and avoids mechanical singularities. The kinematics and mechanics of the joint are modeled and used to develop both open- and closed-loop control systems. Simulated and experimental assessment of the joint performance demonstrates that it can be successfully controlled in 3 degrees of freedom. It is expected that the joint will be a useful option in the development of emerging robotic applications, particularly those requiring miniaturization.


1987 ◽  
Vol 31 (2) ◽  
pp. 176-180 ◽  
Author(s):  
Theodore Marton ◽  
Joan L. Pulaski

Robots and Robotic Systems, regardless of their level of automation, require formal human intervention during normal, degraded or recovery from failure processes. Robotic applications in industry are so recent and expanding so quickly that the unique robotics related human factors safety developments and standards have not yet had a chance to be incorporated into professional educational programs or distributed to human factors engineers who are just being introduced to the field. This paper is offered to alleviate this professional growth deficiency by describing an approach and providing a format for an HF related robotic system safety assessment and development guide based on the newly released ANSI Robot and Robotic System safety standards.


Author(s):  
Steve W. Heim ◽  
Mostafa Ajallooeian ◽  
Peter Eckert ◽  
Massimo Vespignani ◽  
Auke Jan Ijspeert

Purpose The purpose of this paper is to explore the possible roles of active tails for steady-state legged locomotion, focusing on a design principle which simplifies control by decoupling different control objectives. Design/methodology/approach A series of simple models are proposed which capture the dynamics of an idealized running system with an active tail. These models suggest that the overall control problem can be simplified and effectively decoupled via a proper tail design. This design principle is further explored in simulation using trajectory optimization. The results are then validated in hardware using a one degree-of-freedom active tail mounted on the quadruped robot Cheetah-Cub. Findings The results of this paper show that an active tail can greatly improve both forward velocity and reduce body-pitch per stride while adding minimal complexity. Further, the results validate the design principle of using long, light tails compared to shorter heavier ones. Originality/value This paper builds on previous results, with a new focus on steady-state locomotion and in particular deals directly with stance phase dynamics. A novel design principle for tails is proposed and validated.


Author(s):  
Jason I. Reid ◽  
Michael McKinley ◽  
Wayne Tung ◽  
Minerva Pillai ◽  
H. Kazerooni

This paper discusses the control of a medical exoskeleton swing leg that has a “passive” (unactuated) knee. Previous work in legged locomotion has demonstrated the feasibility of achieving natural, energy efficient walking with minimally actuated robotic systems. This work will present early results for a medical exoskeleton that only has actuation that powers the flexion and extension of the biological hip. In this work, a hybrid model of the state dependent kinematics and dynamics of the swing leg will be developed and parameterized to yield swing hip dynamics as a function of desired knee flexion dynamics. This model is used to design swing hip motions that control the flexion behavior of the passive swing knee in a human-like manner. This concept was tested by a paraplegic user wearing a new minimally actuated exoskeleton. The presented results show that a human-like swing phase can be achieved with an exoskeleton that has fewer actuated degrees of freedom than current medical exoskeletons.


2021 ◽  
Vol 16 ◽  
pp. 1-13
Author(s):  
Ruhizan Liza Ahmad Shauri ◽  
Ahmad Badiuzzaman Roslan

This paper presents an overview of force control approaches for robotic systems. It covers three main methods: non-intelligent methods, intelligent methods, and recent methods. In each section, the discussion focused on how the researcher implements their methods in control system to obtain the desired force control for system’s robustness towards external disturbances and internal uncertainties. The purpose of applying force control is to ensure that the executed robotic task does not damage the manipulated object or environment. The benefits for each method were highlighted at the end of each section.


2005 ◽  
Vol 24 (3) ◽  
pp. 504-518 ◽  
Author(s):  
T. Chettibi ◽  
M. Haddad ◽  
A. Labed ◽  
S. Hanchi

2016 ◽  
Vol 8 (2) ◽  
Author(s):  
Yisheng Guan ◽  
Li Jiang ◽  
Haifei Zhu ◽  
Wenqiang Wu ◽  
Xuefeng Zhou ◽  
...  

Agriculture, forestry, and building industry would be prospective fields of robotic applications. High-rise tasks in these fields require robots with climbing skills. Motivated by these potential applications and inspired by animal climbing motion, we have developed a biped climbing robot—Climbot. Built with a modular approach, the robot consists of five joint modules connected in series and two special grippers mounted at the ends, with the scalability of changing degrees-of-freedom (DoFs). With this configuration, Climbot not only has superior mobility on multiple climbing media, such as poles and trusses, but also has the function of grasping and manipulating objects. It is a kind of “mobile” manipulator and represents an advancement in development of climbing robots. In this paper, we first present the development of this climbing robot with modular and bio-inspired methods, and then propose and compare three climbing gaits based on the unique configuration and features of the robot. A series of challenging and comprehensive experiments with the robot climbing in a truss and performing an outdoor manipulation task are carried out, to illustrate the feasibility, the features, the climbing, and manipulating functions of the robot, and to verify the effectiveness of the proposed gaits.


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