Optimum Design and Trafficability Analysis for an Articulated Wheel-legged Forestry Chassis

2021 ◽  
pp. 1-17
Author(s):  
Zhibo Sun ◽  
Dan Zhang ◽  
Zhilong Li ◽  
Shi Yan ◽  
Na Wang
Keyword(s):  
Parameter Optimization ◽  
Kinematic Analysis ◽  
Screw Theory ◽  
Kinematic Model ◽  
Surface Profile ◽  
Error Rates ◽  
Wheel Slip ◽  
Working Environments ◽  
Rigid Model ◽  
Four Bar Linkage

Abstract High trafficability and stability are the most two significant features of the forestry chassis. In this study, in order to improve surface trafficability, a novel articulated wheel-legged forestry chassis(AWLFC) is presented. To balance the trafficability and stability, a serial suspension system which is a combination with the active four-bar linkage articulated suspension (AFLAS) and passive V shape rocker-bogie is proposed. Then, parameter optimization with a comprehensive object function is implemented not only to enhance the trafficability and stability benefit of the structure but also to reduce the wheel slip. After that, through the flexible kinematic model based on screw theory, characteristics such as leveling ability and surface profile accessibility of the chassis are analyzed. The minimum accessible radius is obtained as 3088mm, and the longitudinal and lateral leveling angle reaches to 22° and 28.7° separately. The new chassis performs better on leveling ability and surface profile accessibility than the forestry chassis in the current literature. Finally, compared with the simulation and prototype experiment, error rates of the flexible kinematic analysis are reduced by 12.2% and 8.6% related to the rigid model. Previously inaccessible forestry working environments can be available with the development of AWLFC.

Kinematic analysis of a novel 2(3-RUS) parallel manipulator

Robotica ◽  
2015 ◽  
Vol 34 (10) ◽  
pp. 2241-2256 ◽  
Author(s):  
Róger E. Sánchez-Alonso ◽  
José-Joel González-Barbosa ◽  
Eduardo Castillo-Castaneda ◽  
Jaime Gallardo-Alvarado
Keyword(s):  
Kinematic Analysis ◽  
Parallel Manipulator ◽  
Screw Theory ◽  
Kinematic Model ◽  
Three Dimensional ◽  
Parallel Manipulators ◽  
Analytical Form ◽  
Planar Geometry ◽  
Moving Platform

SUMMARYThis paper introduces a novel 6-DOF parallel manipulator, which is composed of two 3-RUS parallel manipulators that share a common three-dimensional moving platform. Semi-analytical form solutions are easily obtained to solve the forward displacement analysis of the robot using the non-planar geometry of the moving platform, whereas the velocity, acceleration, and singularity analyses are performed using screw theory. A case study is included to show the application of the kinematic model, which is verified with the aid of a commercially available software. Simple kinematic analysis and reduced singular regions are the main benefits of the proposed parallel manipulator.

Kinematic Analysis and Design of a Two Body Articulated Robotic Vehicle

2009 ◽  
Author(s):  
Jesse L. Farmer ◽  
Charles Reinholtz
Keyword(s):  
Computer Simulation ◽  
Kinematic Analysis ◽  
Tracking System ◽  
Kinematic Model ◽  
Cluttered Environments ◽  
Analysis And Design ◽  
Linkage Design ◽  
Robotic Vehicle ◽  
Four Bar Linkage ◽  
Two Bodies

The kinematic analysis and design of an articulated twin body, four-wheel, robotic vehicle is presented. The mobility of the vehicle is improved by connecting the two bodies with a four-bar linkage rather than the standard revolute-jointed body connection used in earlier designs. When properly proportioned, the new linkage design passively minimizes vehicle off-tracking by allowing the rear wheels to closely track the path of the front wheels. This significantly improves the ability of the vehicle to deal with cluttered environments. We outline the theoretical kinematic model of the four-bar linkage as applied to a twin-bodied, differentially driven vehicle. This model is validated through computer simulation as well as experimentation on a fully operational robotic vehicle. The kinematic model provides the foundation for an actively-controlled, linkage-based tracking system.

scholarly journals An Estimator for the Kinematic Behaviour of a Mobile Robot Subject to Large Lateral Slip

2021 ◽  
Vol 11 (4) ◽  
pp. 1594 ◽  
Author(s):  
Andrea Botta ◽  
Paride Cavallone ◽  
Luigi Tagliavini ◽  
Luca Carbonari ◽  
Carmen Visconte ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mobile Robot ◽  
Trajectory Planning ◽  
Kinematic Model ◽  
Close Connection ◽  
Wheel Slip ◽  
Robot Architecture ◽  
Experimental Campaign ◽  
Base Concept ◽  
Kinematic Behaviour

In this paper, the effects of wheel slip compensation in trajectory planning for mobile tractor-trailer robot applications are investigated. Firstly, a kinematic model of the proposed robot architecture is marked out, then an experimental campaign is done to identify if it is possible to kinematically compensate trajectories that otherwise would be subject to large lateral slip. Due to the close connection to the experimental data, the results shown are valid only for Epi.q, the prototype that is the main object of this manuscript. Nonetheless, the base concept can be usefully applied to any mobile robot subject to large lateral slip.

Design and kinematics of a novel double-ring truss deployable antenna mechanism

2021 ◽  
pp. 1-14
Author(s):  
Wen-ao Cao ◽  
Sheng Xi ◽  
Huafeng Ding ◽  
Ziming Chen
Keyword(s):  
Topological Structure ◽  
Screw Theory ◽  
Structural Characteristics ◽  
Kinematic Model ◽  
Structure Design ◽  
Structural Symmetry ◽  
Double Ring ◽  
Joint Axis ◽  
Structure Decomposition ◽  
Topological Scheme

Abstract This paper aims to present the topological structure design and kinematic analysis of a novel double-ring truss deployable satellite antenna mechanism. First, a new topological scheme and a new rectangular prism deployable linkage unit are proposed for constructing the kind of antenna mechanisms. Second, the degree-of-freedom (DOF) of the deployable unit and the antenna mechanism are analyzed based on structure decomposition and screw theory. Third, the kinematic model of the double-ring truss deployable antenna mechanism is established based on its structural characteristics. Finally, a typical numerical example is used to illustrate the effectiveness of the designed mechanism and the established kinematic model. The new double-ring truss deployable antenna mechanism consists of the units with the better structural symmetry, and has simpler joint axis layouts, comparing with the same type of most existing mechanisms.

Slip parameter estimation of a single wheel using a non-linear observer

Robotica ◽  
2008 ◽  
Vol 27 (6) ◽  
pp. 801-811 ◽  
Author(s):  
Z. B. Song ◽  
L. D. Seneviratne ◽  
K. Althoefer ◽  
X. J. Song ◽  
Y. H. Zweiri
Keyword(s):  
Sliding Mode ◽  
Kinematic Model ◽  
Variable Structure ◽  
Lyapunov Stability Theory ◽  
Sliding Mode Observer ◽  
Slip Angle ◽  
Wheel Slip ◽  
Variable Structure System ◽  
Non Linear ◽  
Linear Observer

SUMMARYSliding mode observer is a variable structure system where the dynamics of a nonlinear system is altered via application of a high-frequency switching control. This paper presents a non-linear sliding mode observer for wheel linear slip and slip angle estimation of a single wheel based on its kinematic model and velocity measurements with added noise to simulate actual on-board sensor measurements. Lyapunov stability theory is used to establish the stability conditions for the observer. It is shown that the observer will converge in a finite time, provided the observer gains satisfy constraints based on a stability analysis. To validate the observer, linear and two-dimensional (2D) test rigs are specially designed. The sliding mode observer is tested under a variety of conditions and it is shown that the sliding mode observer can estimate wheel slip and slip angle to a high accuracy. It is also shown that the sliding mode observer can accurately predict wheel slip and slip angle in the presence of noise, by testing the performance of the sliding mode observer after adding white noise to the measurements. An extended Kalman filter is also developed for comparison purposes. The sliding mode observer is better in terms of prediction accuracy.

Kinematic Analysis of Spherical Four-Bar Linkages via the Inflection Cubic and Thales Ellipse

2015 ◽  
Author(s):  
Giorgio Figliolini ◽  
Jorge Angeles
Keyword(s):  
Special Interest ◽  
Kinematic Analysis ◽  
Vector Fields ◽  
Three Dimensions ◽  
Unique Point ◽  
Planar Case ◽  
Acceleration Vector ◽  
The Subject ◽  
Four Bar Linkage ◽  
Spherical Motion

The subject of this paper is the formulation of a specific algorithm for the kinematic analysis of spherical four-bar linkages via the inflection spherical cubic and spherical Thales ellipse by devoting particular attention to the crossed four-bar linkage (anti-parallelogram). Moreover, both the inflection and the elliptic cones, which represent the equivalent of the Bresse cylinders of the planar case in three-dimensions, are obtained by showing the particular properties of the spherical motion in terms of the curvature of a coupler curve and both the velocity and acceleration vector fields. Of special interest are also the cases in which the three acceleration poles coincide at one unique point or in two plus one, which depends on the intersections of two spherical curves of third and second degree.

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