scholarly journals Condition analysis of a multicopter carried with passive skid for rough terrain landing

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Maozheng Xu ◽  
Taku Senoo ◽  
Takeshi Takaki
Keyword(s):  
Numerical Analysis ◽  
Contact Point ◽  
Static Model ◽  
Center Of Gravity ◽  
Rough Terrain ◽  
Robot Arm ◽  
Arbitrary Plane

AbstractThis paper describes the condition analysis of a multicopter carried with a proposed device for rough terrain landing. Based on a multicopter carried with an electrical robot arm for grasping, we proposed a method to determine whether the skid-carried multicopter can land on an arbitrary slope or not. We established the static model of the entire device, and analyzed the conditions under which the arm and skid can contact the arbitrary plane and the COG (Center of Gravity), which includes the mass of passive skid, multicopter body and each link of the robot arm. Further, we proposed a method to analyze whether the entire device can land stably. By analyzing that the projection of the entire device’s COG is inside or outside the triangle, that comprises the contact point between the device and the uneven ground, we can determine whether the device can land successfully and the condition for capable landing is concluded. After the numerical analysis, the verification experiment is conducted, and by comparing the result of analysis with the experiment, the accuracy of the analysis can be demonstrated.

Normalized Energy Stability Margin Based Analysis of Omni-Directional Static Walking of a Quadruped Robot on Rough Terrain

2011 ◽  
Vol 383-390 ◽  
pp. 7401-7405
Author(s):  
Lei Zhang ◽  
Shan Gao
Keyword(s):  
Stability Criterion ◽  
Simulation Experiment ◽  
Stability Margin ◽  
Quadruped Robot ◽  
Center Of Gravity ◽  
Energy Stability ◽  
Rough Terrain ◽  
The Stability

With Normalized Energy Stability Margin(Sne ) as stability criterion, this paper studies the tumbles of omni-directional static walking of a quadruped robot around the line connecting two adjacent supporting legs on rough terrain, proposes the method to improve the stability of quadruped robot by increasing the (Sne ) value, which is realized by lowering the height of center of gravity(COG), and finally substantiates the feasibility of the method through a simulation experiment.

Direct Teaching Method to Constrain Movement on Arbitrary Plane using 5-Axes Robot Arm

2016 ◽  
Vol 2016 (0) ◽  
pp. 2P2-04a5
Author(s):  
Akihito ITO ◽  
Nobutaka TSUJIUCHI ◽  
Shunsuke KIKUCHI ◽  
Yuji NAKAIE ◽  
Yoichiro NAKAMURA
Keyword(s):  
Teaching Method ◽  
Robot Arm ◽  
Arbitrary Plane ◽  
Direct Teaching

Optimal Control of the Searching and Tracking Head (STH) for Self Propelled Anti Aircraft Vehicle

2011 ◽  
Vol 180 ◽  
pp. 27-38 ◽  
Author(s):  
Zbigniew Koruba
Keyword(s):  
Optimal Control ◽  
Computer Simulation ◽  
Numerical Analysis ◽  
Rough Terrain ◽  
Mobile Vehicle ◽  
Simulation Results

The paper presents an algorithm for controlling a searching and tracking head (STH) mounted on a mobile vehicle. A numerical analysis was conducted to establish the dynamics of the controlled STH due to the kinematic action of the vehicle moving over rough terrain. Some of the computer simulation results were represented graphically.

Safety of Spur Gear Design Under Non-Ideal Conditions With Uncertainty

2010 ◽  
Author(s):  
Kyle Stoker ◽  
Anirban Chaudhuri ◽  
Nam Ho Kim
Keyword(s):  
Numerical Analysis ◽  
Contact Pressure ◽  
Contact Point ◽  
Spur Gear ◽  
Hertzian Contact ◽  
Analytical Models ◽  
Bending Stress ◽  
Element Analysis ◽  
Gear Design ◽  
Bending Stresses

The current practice of gear design is based on the Lewis bending and Hertzian contact models. The former provides the maximum stress on the gear base, while the latter calculates the contact pressure at the contact point between the gear and pinion. Both calculations are obtained at the reference configuration with ideal conditions; i.e., no tolerances and clearances. The first purpose of this paper is to compare these two analytical models with the numerical results, in particular, using finite element analysis. It turns out that the estimations from the two analytical equations are closely matched with those of the numerical analysis. The numerical analysis also yields the variation of contact pressures and bending stresses according to the change in the relative position between gear and pinion. It has been shown that both the maximum bending stress and contact pressure occur at non-reference configurations, which should be considered in the calculation of a safety factor. In reality, the pinion-gear assembly is under the tolerance of each part and clearance between the parts. The second purpose of this report is to estimate the effect of these uncertain parameters on the maximum bending stress and contact pressure. For the case of the selected gear-pinion assembly, it turns out that due to a 0.57% increase of clearance, the maximum bending stress is increased by 4.4%. Due to a 0.57% increase of clearance, the maximum contact pressure is increased by 17.9%.

scholarly journals Trajectory planning of the nursing robot based on the center of gravity for aluminum alloy structure

2021 ◽  
Vol 60 (1) ◽  
pp. 731-743
Author(s):  
Libo Zhang ◽  
Hanjun Gao ◽  
Huichao Xu ◽  
Jing Song
Keyword(s):  
Trajectory Planning ◽  
Inverse Kinematics ◽  
Center Of Pressure ◽  
Pressure Sensors ◽  
Center Of Gravity ◽  
Robot Arm ◽  
Planning Algorithm ◽  
Movement Stability ◽  
The Stability ◽  
The Mathematical Model

Abstract In this paper, the robot arm is manufactured to increase the structural strength and improve safety. The stability of the nursing robot in the process of carrying out the typical nursing task of holding patients was studied, and the influence of the center of gravity on the movement stability of the nursing robot was analyzed. The mathematical model of the stability of the robot is built by using the inverse kinematics solution of the robot. By studying the trajectory planning of a nursing robot under the condition of ZMP constraint, the robot can move safely and optimally along the prescribed trajectory between two working points. The simulation results show that the algorithm can significantly improve the work safety of the robot. In the experiment, four pressure sensors are used to measure the pressure of four wheels on the ground, the data are obtained and substituted into the expression of center of pressure (COP) method. The results show that the stability is in a reasonable moving area without any hidden danger, and its COP value is less than the stable qualitative boundary, which verifies the rationality and effectiveness of the optimal center of gravity stability planning algorithm.

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