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Journal ArticleDOI

Design of a robust stair-climbing compliant modular robot to tackle overhang on stairs

01 Mar 2019-Robotica (Cambridge University Press)-Vol. 37, Iss: 3, pp 428-444
TL;DR: In this article, the concept and parameter design of a robust stair-climbing compliant modular robot, capable of tackling stairs with overhangs, is discussed, along with establishing a concept design, the robust design parameters are set to minimize performance variations.
Abstract: This paper discusses the concept and parameter design of a robust stair-climbing compliant modular robot, capable of tackling stairs with overhangs. Geometry modifications of the periphery of the wheels of our robot helped in tackling overhangs. Along with establishing a concept design, the robust design parameters are set to minimize performance variations. The Grey-based Taguchi method is applied to provide an optimal setting for the design parameters of the robot. The robot prototype is shown to have successfully scaled stairs of varying dimensions, with overhang, thus corroborating the analysis performed.
Citations
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Journal ArticleDOI
01 Nov 2020-Robotica
TL;DR: A grip-based climbing robot designed to accomplish the climbing process through the trusses and infrastructures in order to perform inspecting and manipulating tasks and can successfully climb through a truss and perform its operating task by the aid of the employed adaptive controller in an accurate way.
Abstract: In this paper, design, modeling, and control of a grip-based climbing robot are performed, which consists of a triangular chassis and three actuating legs. This robot can climb through any trusses, pipeline, and scaffolds structures and can perform any inspectional and operational tasks in the high height which decreases the falling danger of operation and increases the safety of the workers. The proposed robot can be substituted for the workers to decrease the risk of death danger and increase the safety of the operation. Since these kinds of infrastructures are truss shaped, the traditional wheel-based climbing robots are not able to travel through these structures. Therefore, in this paper, a grip-based climbing robot is designed to accomplish the climbing process through the trusses and infrastructures in order to perform inspecting and manipulating tasks. Hence, a proper mechanism for the mentioned robot is designed and its related kinematic and kinetic models are developed. Robot modeling is investigated for two different modes including climbing and manipulating phases. Considering the redundancy of the proposed robot and the parallel mechanism employed in it, the active joints are selected in a proper way and its path planning is performed to accomplish the required missions. Concerning the climbing mode, the required computed torque method (CTM) is calculated by the inverse dynamics of the robot. However, for the manipulation mode, after path planning, two controlling strategies are employed, including feedback linearization (FBL) and adaptive force control, and their results are compared as well. It is shown that the latter case is preferable since the external forces implemented on the end effector tool is not exactly predetermined and thus, the controller should adapt the robot with the exerted force pattern of the manipulator. The modeling correctness is investigated by performing some analytic and comparative simulation scenarios in the MATLAB and comparing the results with the MSC-ADAMS ones, for both climbing and manipulating phases. The efficiency of the designed controller is also proved by implementing an unknown force pattern on the manipulator to check its efficiency toward estimating the mentioned implemented forces and compensating the errors. It is shown that the designed robot can successfully climb through a truss and perform its operating task by the aid of the employed adaptive controller in an accurate way.

5 citations

Journal ArticleDOI
TL;DR: In this paper, the main mold properties such as permeability and hardness are evaluated in green sand-casting process, and the quality of the mould in the green sand casting process plays a vital role to achieve good quality castings.
Abstract: The quality of the mould in green sand-casting process plays a vital role to achieve good quality castings. In this research work, the main mould properties such as permeability and hardness are fo...

3 citations

Proceedings ArticleDOI
23 May 2022
TL;DR: The TrussBot as discussed by the authors is composed of 3D-printed tetrahedral modules connected at the corners with compliant joints and can be actuated through a network of tendons which pinch vertices together and apply a twisting motion due to the structure's connectivity.
Abstract: Modular and truss robots offer the potential of high reconfigurability and great functional flexibility, but common implementations relying on rigid components often lead to highly complex actuation and control requirements. This paper introduces a new type of modular, compliant robot: TrussBot. TrussBot is composed of 3D-printed tetrahedral modules connected at the corners with compliant joints. We propose a truss geometry, analyze its deformation modes, and provide a simulation framework for predicting its behavior under applied loads and actuation. The TrussBot is geometrically constrained, thus requiring compliant joints to move. The TrussBot can be actuated through a network of tendons which pinch vertices together and apply a twisting motion due to the structure's connectivity. The truss was demonstrated in a physical prototype and compared to simulation results.
Book ChapterDOI
01 Jan 2021
TL;DR: In this article, the authors developed an efficient high mobility suspension system that is capable of travelling through rough terrain using a four wheeled rover, where two motors are located inside the body for increased reliability and efficiency.
Abstract: The methodology used in the Mars exploration and curiosity rover by Mars Science Laboratory is rocker bogie. The term rocker derives from the suspension system with large forward leg on each side of the vehicle chassis on either side which exhibits automated wheel movement, henceforth when one side of the vehicle rocker goes up, the other side goes down and maintain an average pitch level. Earlier research has envisaged that the Rocker-Rovers are much suitable for conducting scientific experiments like travelling to many meters to tens of kilometres. However, the recent mobility designs are complex, using many wheels or legs. Moreover, such rocker bogies can achieve only minimum distance transverse on field like agriculture land, rough land, inclined, stairs and obstacle surfaces which concludes that greater mobility experiments need to be conducted. There are most cases noted that mechanical failures were caused due to harsh environment. Hence, for surveillance in rough terrains, a robust design of rover is required. This paper focused on development of an efficient high mobility suspension system that is capable of travelling through rough terrain using a four wheeled rover. The primary mechanical feature of the rocker bogie design is arrived by using only two motors for mobility and drive line easiness. Motors are located inside the body for increased reliability and efficiency, while considering the thermal variation to be minimum. Increased stability requires both front wheels to be climb first, put forth the necessity of four wheels for driving the rover. The Rocker-Rover suspension system has a vigorous capability to overcome the uneven terrain because of its equal distribution of the pressure over its six wheels. Moreover, this article has implemented a rover with TSM (Total Surveillance Manager) which is an intelligent surveillance and security robot system, designed for monitoring behaviours and activities in the region of interest. The proposed prototype utilizes multiple types of surveillance devices including robots, CCTV cameras, and sensors
Journal ArticleDOI
11 May 2023-Robotica
TL;DR: In this article , a climbing robot equipped with a gripper-based locomotion system was designed and manufactured at Kharazmi University to climb scaffold structures and trusses to accomplish inspectional and operational tasks.
Abstract: Abstract There are a lot of high-height structures that should be inspected or manipulated frequently due to maintenance purposes. According to the safety considerations and time or cost limitations, substituting the human operator with an automatic robot is inevitable. The main objective of this paper is to design and manufacture a novel climbing robot equipped with grip-based locomotion system which can climb through scaffold structures and trusses to accomplish inspectional and operational tasks. The proposed robot has good maneuverability and stability. The proposed robot is manufactured in order to verify the simulation results with experimental data. The chassis and its corresponding grippers are designed first, and the corresponding model of the system is extracted. This model is used then for designing the controlling strategy of the system. The path planning of the robot is conducted to realize the climbing process by the robot during several steps in an optimum way. The prototype of the proposed robot is manufactured at Kharazmi University called KharazmBot. Experimental results not only show the capability of the manufactured robot toward ascending the mentioned structures but also prove its high stability as a result of its designed gripper and also its good maneuverability as a result of its over-actuated mechanism. Thus, it is concluded that the designed and manufactured climbing robot of this paper can successfully ascend through the pipes and trusses and perform a desired inspectional or operational task with good accuracy and safety while its stability is also satisfied.
References
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Proceedings ArticleDOI
17 Dec 2015
TL;DR: This work extends the functionality of a novel compliant modular robot to ascend and descend stairs of dimensions that are also typical of an urban setting by equipping the robot's link joints with optimally designed passive spring pairs that resist clockwise and counter clockwise moments generated by the ground during the climbing motion.
Abstract: Stair Climbing is a key functionality desired for robots deployed in Urban Search and Rescue (USAR) scenarios. A novel compliant modular robot was proposed earlier to climb steep and big obstacles. This work extends the functionality of this robot to ascend and descend stairs of dimensions that are also typical of an urban setting. Stair Climbing is realized by equipping the robot's link joints with optimally designed passive spring pairs that resist clockwise and counter clockwise moments generated by the ground during the climbing motion. This 3-module robot is only propelled by wheel actuators. Desirable stair climbing configurations are estimated a-priori and used to obtain the optimal stiffness for springs. Extensive numerical simulation results over different stair configurations are shown. The numerical simulations are corroborated by experimentation using the prototype and its performance is tabulated for different types of surfaces.

15 citations

Proceedings ArticleDOI
17 Dec 2015
TL;DR: This paper proposes a new wheel mechanism, the swing-grouser wheel, which can climb high steps (especially in low friction environments) and has high energy efficiency and the energy efficiency was better than that of the previous model.
Abstract: Generally, wheel mechanisms are inferior to a tracked or walking mechanism in terms of step climbability or traversability in rough terrain; however, they are superior in terms of energy efficiency, structural simplicity, and carrying capacity. This paper proposes a new wheel mechanism, the swing-grouser wheel, which can climb high steps (especially in low friction environments) and has high energy efficiency. In addition, the swing-grouser wheel can climb regardless of the body inclination. Its merits are compared to the results of prior studies. Furthermore, the performance of the swing-grouser wheel was confirmed using a real device experiment and a 2D physics simulation, and improved using a full search of the parameters of the swing-grouser wheel. As a result, one improved parameter resulted in climbing at over 68% of the wheel diameter in a low friction environment; additionally, the energy efficiency was better than that of the previous model.

12 citations

Journal ArticleDOI
TL;DR: In this paper, an analysis method to make the rocker bogie mechanism can climb up a stair is achieved, and the stair climbability graph (SCG) determined with the length and the height of a stair was drawn.
Abstract: An analysis method to make the rocker bogie mechanism can climb up a stair is achieved in this paper. To verify whether the rocker bogie, with certain lengths of the linkages and radii of the wheels, could climb up a target stair or not, a kinematic analysis and its posture are determined. The trace of the center of mass of the rocker bogie was considered and the situation that three wheels contact the front side of the stair is analyzed. With this two analyses, the stair climbability graph (SCG) determined with the length and the height of a stair was drawn. The SCG shows the climbable stair group for the rocker bogie with certain size. Two prototypes of rocker bogie which has different lengths of linkages were designed and tested on two different stairs. As same result of the SCG, the first prototype rocker bogie with small rocker linkage can climb up the stair (length 450 mm and height 150 mm) but cannot climb up the other stair (length 300 mm and height 175 mm). The second prototype rocker bogie with large rocker linkage can climb up both stairs.

11 citations

Journal ArticleDOI
01 Feb 2017-Robotica
TL;DR: An optimal wheel-torque controller is proposed that minimizes the traction-to-normal force ratios of all the wheels at every instant of its motion to maintain static stability and desired wheel speed.
Abstract: This paper discusses the development of an optimal wheel torque controller for a compliant modular robot. The wheel actuators are the only actively controllable elements in this robot. For this type of robots, wheel-slip could offer a lot of hindrance while traversing on uneven terrains. Therefore, an effective wheel-torque controller is desired that will also improve the wheel-odometry and minimize power consumption. In this work, an optimal wheel-torque controller is proposed that minimizes the traction-to-normal force ratios of all the wheels at every instant of its motion. This ensures that, at every wheel, the least traction force per unit normal force is applied to maintain static stability and desired wheel speed. The lower this is, in comparison to the actual friction coefficient of the wheel-ground interface, the more margin of slip-free motion the robot can have. This formalism best exploits the redundancy offered by a modularly designed robot. This is the key novelty of this work. Extensive numerical and experimental studies were carried out to validate this controller.

11 citations

Journal ArticleDOI
TL;DR: To efficiently perform each of the dynamic simulations, this article develops, using tools from modern screw theory, new recursive algorithms for the forward and inverse dynamics of the class of redundantly actuated mechanisms described.
Abstract: This article presents a simulation-based strategy for sizing the actuators of a redundantly actuated robotic mechanism. The class of robotic mechanisms we consider may contain one or more closed loops and possess an arbitrary number of active and passive joints, and the number of actuators may exceed the mechanism's kinematic degrees of freedom. Our approach relies on a series of dynamic simulations of the mechanism, by applying Taguchi's method to systematically perform the simulations. To efficiently perform each of the dynamic simulations, we develop, using tools from modern screw theory, new recursive algorithms for the forward and inverse dynamics of the class of redundantly actuated mechanisms described. © 2002 Wiley Periodicals, Inc.

10 citations