PRINCIPLE, CONSTRUCTION AND KINEMATIC ANALYSIS FOR THE OMNIDIRECTIONAL MOBILE ROBOT——ICE-SKATER ROBOT

Three main basic types of locomotion for a mobile robot were introduced and the advantages and disadvantages of a legged mobile robot, a wheeled mobile robot and an articulated mobile robot were also discussed. A new type of leg wheeled mobile robot was introduced which combines the adaptability of legged robot with the stability of wheeled robot. On the basis of the structure of the wheels, the paper described the principle of the ice skater robot developed from Roller walker and ALDURO and its construction. The paper also established an inertia coordinate system and a wheel coordinate system, and analyzed the configuration or the posture and the related kinematic constraints of the robot according to some assumptions. Based on the motion principle, a logic based coordinated control system and corresponded flowchart were designed. At last, taking the ice skater robot as an example the paper expounded its application and the actual experiment proved its feasibility.

An approach for determination of lateral limit angle in kinematic planar sliding analysis for rock slopes

Planar sliding is one of the frequently observed types of failure in rock slopes.Kinematic analysis is a classic and widely used method to examine the potential failure modes in rock masses.The accuracy of planar sliding kinematic analysis is significantly influenced by the value assigned to the lateral limit angleγlim.However,the assignment ofγlim is currently used generally based on an empirical criterion.This study aims to propose an approach for determining the value ofγlim in deterministic and probabilistic kinematic planar sliding analysis.A new perspective is presented to reveal thatγlim essentially influences the probability of forming a potential planar sliding block.The procedure to calculate this probability is introduced using the block theory method.It is found that the probability is correlated with the number of discontinuity sets presented in rock masses.Thus,different values ofγlim for rock masses with different sets of discontinuities are recommended in both probabilistic and deterministic planar sliding kinematic analyses;whereas a fixed value ofγlim is commonly assigned to different types of rock masses in traditional method.Finally,an engineering case was used to compare the proposed and traditional kinematic analysis methods.The error rates of the traditional method vary from 45%to 119%,while that of the proposed method ranges between 1%and 17%.Therefore,it is likely that the proposed method is superior to the traditional one.

Evaluation of slope stability through rock mass classification and kinematic analysis of some major slopes along NH-1A from Ramban to Banihal, North Western Himalayas

The network of Himalayan roadways and highways connects some remote regions of valleys or hill slopes,which is vital for India’s socio-economic growth.Due to natural and artificial factors,frequency of slope instabilities along the networks has been increasing over last few decades.Assessment of stability of natural and artificial slopes due to construction of these connecting road networks is significant in safely executing these roads throughout the year.Several rock mass classification methods are generally used to assess the strength and deformability of rock mass.This study assesses slope stability along the NH-1A of Ramban district of North Western Himalayas.Various structurally and non-structurally controlled rock mass classification systems have been applied to assess the stability conditions of 14 slopes.For evaluating the stability of these slopes,kinematic analysis was performed along with geological strength index(GSI),rock mass rating(RMR),continuous slope mass rating(CoSMR),slope mass rating(SMR),and Q-slope in the present study.The SMR gives three slopes as completely unstable while CoSMR suggests four slopes as completely unstable.The stability of all slopes was also analyzed using a design chart under dynamic and static conditions by slope stability rating(SSR)for the factor of safety(FoS)of 1.2 and 1 respectively.Q-slope with probability of failure(PoF)1%gives two slopes as stable slopes.Stable slope angle has been determined based on the Q-slope safe angle equation and SSR design chart based on the FoS.The value ranges given by different empirical classifications were RMR(37-74),GSI(27.3-58.5),SMR(11-59),and CoSMR(3.39-74.56).Good relationship was found among RMR&SSR and RMR&GSI with correlation coefficient(R 2)value of 0.815 and 0.6866,respectively.Lastly,a comparative stability of all these slopes based on the above classification has been performed to identify the most critical slope along this road.

Configuration and Kinematics of a 3-DOF Generalized Spherical Parallel Mechanism for Ankle Rehabilitation

The kinematic equivalent model of an existing ankle-rehabilitation robot is inconsistent with the anatomical structure of the human ankle,which influences the rehabilitation effect.Therefore,this study equates the human ankle to the UR model and proposes a novel three degrees of freedom(3-DOF)generalized spherical parallel mechanism for ankle rehabilitation.The parallel mechanism has two spherical centers corresponding to the rotation centers of tibiotalar and subtalar joints.Using screw theory,the mobility of the parallel mechanism,which meets the requirements of the human ankle,is analyzed.The inverse kinematics are presented,and singularities are identified based on the Jacobian matrix.The workspaces of the parallel mechanism are obtained through the search method and compared with the motion range of the human ankle,which shows that the parallel mechanism can meet the motion demand of ankle rehabilitation.Additionally,based on the motion-force transmissibility,the performance atlases are plotted in the parameter optimal design space,and the optimum parameter is obtained according to the demands of practical applications.The results show that the parallel mechanism can meet the motion requirements of ankle rehabilitation and has excellent kinematic performance in its rehabilitation range,which provides a theoretical basis for the prototype design and experimental verification.

Three Dimensional Kinematics Analysis of the Independent Suspension Multibody System

Based on the theory of multibody system dynamics, the spatial kinematics analysis of the Mcpherson independent suspension widely used in the car was carried out. A practical and simpler method was provided to reduce the number of the generalized coordinates and constraint functions. By solving the nonlinear equations, the motion of any points in the whole suspension and wheel system can be predicted, including the spatial changes of the wheel alignment parameters which are of great importance to the car performances.

Kinematic Analysis and Experimental Verification on the Locomotion of Gecko

This paper presents a kinematic analysis of the locomotion of a gecko,and experimental verification of the kinematic model.Kinematic analysis is important for parameter design,dynamic analysis,and optimization in biomimetic robot research. The proposed kinematic analysis can simulate,without iteration,the locomotion of gecko satisfying the constraint conditions that maintain the position of the contacted feet on the surface.So the method has an advantage for analyzing the climbing motion of the quadruped mechanism in a real time application.The kinematic model of a gecko consists of four legs based on 7-degrees of freedom spherical-revolute-spherical joints and two revolute joints in the waist.The motion of the kinematic model is simulated based on measurement data of each joint.The motion of the kinematic model simulates the investigated real gecko's motion by using the experimental results.The analysis solves the forward kinematics by considering the model as a combination of closed and open serial mechanisms under the condition that maintains the contact positions of the attached feet on the ground. The motions of each joint are validated by comparing with the experimental results.In addition to the measured gait,three other gaits are simulated based on the kinematic model.The maximum strides of each gait are calculated by workspace analysis.The result can be used in biomimetic robot design and motion planning.

Kinematics Analysis of Mechanisms Based on Virtual Assembly

Currently, virtual assembly technology has attracted increasing attention due to considerations of solving assembly problems in virtual environment before actual assembly in manufactory. Previous studies on kinematic analysis of mechanism only aim at analyzing motion law of single mechanism, but can not simulate the multi-mechanisms motion process at the same time, let alone simulating the automatic assembly process of products in a whole assembly workshop. In order to simulate the assembly process of products in an assembly workshop and provide effective data for analyzing mechanical performance after finishing assembly simulation in virtual environment, this study investigates the kinematics analysis of mechanisms based on virtual assembly. Firstly, in view of the same function of the kinematic pairs and the assembly constraints on restricting the motion of components （subassembly or part）, the method of identifying kinematic pairs automatically based on assembly constraints is presented. The information of kinematic pairs can be obtained through calculating the constraint degree of the assembly constraints. Secondly, the incidence matrix eliminating element method is proposed in order to search the information and establish the models of mechanisms automatically after finishing assembly simulation in virtual environment. Both methods have important significance for reducing the workload of pretreatment and promoting the level of automation of kinematics analysis. Finally, the method of kinematics analysis of mechanisms is presented. Based on Descartes coordinates, three types of kinematics equations are formed. The parameters, like displacement, velocity, and acceleration, can be obtained by solving these equations. All these data are important to analyze mechanical performance. All the methods are implemented and validated in the prototype system virtual assembly process planning（VAPP）. The mechanism models are established and simulated in the VAPP system, and the result curves are shown accurately. The proposed kinematics analysis of mechanisms based on virtual assembly provides an effective method for simulating product assembly process automatically and analyzing mechanical performance after finishing assembly simulation.

Kinematic analysis of geosynthetics-reinforced steep slopes with curved sloping surfaces and under earthquake regions

A procedure of kinematic analysis is presented in this study to assess the reinforcement force of geosynthetics required under seismic loadings, particularly for steep slopes which are hardly able to maintain its stability. Note that curved sloping surfaces widely exist in natural slopes, but existing literatures were mainly focusing on a planar surface in theoretical derivation, due to complicated calculations. Moreover, the non-uniform soil properties cannot be accounted for in conventional upper bound analysis. Pseudo-dynamic approach is used to represent horizontal and vertical accelerations which vary with time and space. In an effort to resolve the above problems, the discretization technique is developed to generate a discretized failure mechanism, decomposing the whole failure block into various components. An elementary analysis permits calculations of rates of work done by external and internal forces. Finally, the upper bound solution of the required reinforcement force is formulated based on the work rate-based balance equation. A parametric study is carried out to give insights on the implication of influential factors on the performance of geosynthetic-reinforced steep slopes.

Generalized Kinematics Analysis of Hybrid Mechanisms Based on Screw Theory and Lie Groups Lie Algebras

Advanced mathematical tools are used to conduct research on the kinematics analysis of hybrid mechanisms,and the generalized analysis method and concise kinematics transfer matrix are obtained.In this study,first,according to the kinematics analysis of serial mechanisms,the basic principles of Lie groups and Lie algebras are briefly explained in dealing with the spatial switching and differential operations of screw vectors.Then,based on the standard ideas of Lie operations,the method for kinematics analysis of parallel mechanisms is derived,and Jacobian matrix and Hessian matrix are formulated recursively and in a closed form.Then,according to the mapping relationship between the parallel joints and corresponding equivalent series joints,a forward kinematics analysis method and two inverse kinematics analysis methods of hybrid mechanisms are examined.A case study is performed to verify the calculated matrices wherein a humanoid hybrid robotic arm with a parallel-series-parallel configuration is considered as an example.The results of a simulation experiment indicate that the obtained formulas are exact and the proposed method for kinematics analysis of hybrid mechanisms is practically feasible.

Kinematic Analysis and Trajectory Planning of J-Groove Welding Robot

This paper introduces the complexity and particularity of tube-sphere intersection weld(J-groove weld) and establishes the mathematical model of tube-sphere intersection trajectory.Based on the characteristics of J-groove welds,the computational process of welding gun orientation is first simplified.Then the kinematic algorithm of a welding robot is obtained according to screw theory and exponential product formula.Finally,Solidworks and SimMechanics are employed to simulate the kinematics of the welding robot,which proves the feasibility of the kinematic algorithm.

Kinematic,Workspace and Force Analysis of A Five-DOF Hybrid Manipulator R(2RPR)R/SP+RR

In the present study,the over-constrained hybrid manipulator R(2RPR)R/SP+RR is considered as the research objective.In this paper,kinematics of the hybrid manipulator,including the forward and inverse position,are analyzed.Then,the workspace is checked based on the inverse position solution to evaluate whether the workspace of the hybrid manipulator meets the requirements,and the actual workspace of the hybrid robot is analyzed.After that,the force analysis of the over-constrained parallel mechanism is carried out,and an ADAMS-ANSYS rigid-flexible hybrid body model is established to verify the simulation.Based on the obtained results from the force analysis,the manipulator structure is designed.Then,the structure optimization is carried out to improve the robot stiffness.Finally,calibration and workspace verification experiments are performed on the prototype,cutting experiment of an S-shaped aluminum alloy workpiece is completed,and the experiment verifies the machining ability of the prototype.This work conducts kinematics,workspace,force analyses,structural optimization design and experiments on the over-constrained hybrid manipulator R(2RPR)R/SP+RR,providing design basis and technical support for the development of the novel hybrid manipulator in practical engineering.

Kinematics analysis for obstacle-surmounting capability of a joint double-tracked robot

A double-tracked robot is designed from mechanical and control perspectives,which consists of two segments connected with a swing joint. As the angle between the two segments of the robot platform can be changed,the robot can move like a four-tracked robot on many terrains. The center of gravity（ CG） kinematics model is established,which plays an important role in the process of traveling over obstacles and climbing up stairs. Using this model,the CG change situation and the maximal height of the climbable obstacle are obtained. Then the relationship between the robot pitch angle and the height of the obstacle is established. Finally,a reasonable system structure for the robot is designed and its kinematics analysis for obstacle-surmounting capability is conducted through experiments.

Configuration and kinematics analysis of locking-releasing mechanism for side-loaded lunar rover

In order to save space for storing precision equipments,lower the center of mass of Lander and reduce lunar rover's dimension constraint limited by mechanism of Lander,the locking-releasing mechanism of side-loaded lunar rover loaded outside Lander is presented,which is a kind of metamorphic mechanism.To ensure the working of this mechanism as the metamorphic process designed,configuration analysis of the locking-releasing mechanism is carried out,and topological structures are described by Huston lower numbered arrays.A kinematic mathematical model of the mechanism is established through homogeneous transformation matrix.The kinematic simulation validates the feasibility of the locking-releasing mechanism when the configurations are shifted from one to the other.

Slope mass rating and kinematic analysis of slopes along the national highway-58 near Jonk, Rishikesh, India

The ro ad n etw o rk in th e H im alayan terrain , connecting re m o te areas e ith e r in th e valleys o r on th e hillslopes, plays a pivotal role in socio-econom ic d e v elo p m en t ofIn d ia. The planning, d ev elo p m en t an d evenm ain ten an ce o f ro ad an d rail netw o rk s in such precarious terrain s are alw ays a challenging task becauseo f com plexities p osed by topography, geological stru ctu res, varied lithology an d neotectonics. Increasingp o p u latio n an d c o n stru ctio n o f roads have led to destab ilisatio n o f slopes, th u s leading to m ass w astingand m ovem ent, fu rth e r aggravation d u e to recen t events o f cloud bu rsts and u n p re c e d e n te d flash floods.V ulnerability analysis o f slopes is an im p o rta n t co m p o n e n t for th e ＂Landslide H azard A ssessm ent＂ and＂Slope Mass C h aracterisation＂ guide p lan n ers to p red ict an d choose suitable w ays for c o n stru ctio n ofroads and o th e r en g in eerin g stru ctu res. The pro b lem o f landslides along th e n ational highw ay-58 （NH-58） from Rishikesh to D evprayag is a co m m o n scene. The slopes along th e NH-58 b e tw e e n Jonk andRishikesh w ere investigated, w h ich experienced v ery heavy traffic especially from M arch to A ugust dueto pilgrim age to K edarnath shrine. On th e basis o f slope m ass rating （SMR） investigation, th e area falls instable class, an d landslide susceptibility score （LSS） values also indicate th a t th e slopes u n d e r investigationfall in low to m o d erate v ulnerability to landslide. More atte n tio n s should be paid to th e slopes toachieve g reater safe an d econom ic b enefits along th e highw ay.

Kinematic Analysis of Persian Joint Using 3D Rotation Matrix

This paper has been done on study kinematic problem of Persian joint in a general way. In this study, instead of using simulation analysis method as in the previous researches, the 3D rotation matrix method is applied to present the relationship of angular velocities of input shaft and output shaft. The result shows that when the angle between intersecting shafts changes from 0 to 135°, the angular velocity is maintained constant. This new result completely matches with analysis from kinematic simulation of this mechanism. The obtained result is an important base to solve dynamic problem in order to develop the applicability of this joint in reality.

Design and Kinematics Analysis of Support Structure for Multi-Configuration Rigid-Flexible Coupled Modular Deployable Antenna

In order to meet the urgent need for diversified and multi-functional deployable antennas in many major national aerospace projects,such as interstellar exploration,the fourth phase of lunar exploration project,and the industrial application of Bei Dou,a deployable antenna structure composed of hexagonal prism and pentagonal prism modules is proposed.Firstly,the arrangement and combination rules of pentagonal prism and hexagonal prism modules on the plane were analyzed.Secondly,the spatial geometric model of the deployable antenna composed of pentagonal prism and hexagonal prism modules was established.The influence of module size on the antenna shape was then analyzed,and the kinematic model of the deployable antenna established by coordinate transformation.Finally,the above model was verified using MATLAB software.The simulation results showed that the proposed modular deployable antenna structure can realize accurate connection between modules,complete the expected deployment and folding functional requirements.It is hoped that this research can provide reference for the basic research and engineering application of deployable antennas in China.

Analysis and Simulation of Kinematical Performances of Two Kinds of Parallel Mechanisms Based on the Plane Sprayer

Two kinds of 2-dof parallel mechanisms are proposed in this paper which can be used as the actuator for the plane sprayer. The direct and inverse kinematics solutions of the two kinds of mechanisms are derived on the end operating point and two workspaces are analyzed and compared. The kinematics models of the end operating point of two mechanisms are simulated by Matlab examples obtaining variation of kinematics parameters of these two mechanisms. The research of this paper provides the basis for the selection of mechanism, trajectory planning of the end operating point on the sprayer and often some practical value for trajectory analysis and structure design of the plane sprayer.

Kinematic Analysis of the Neck and Upper Extremities During Walking in Healthy Young Adults

The objective of this paper is to quantify the local stabilities of the neck and upper extremities （right/left shoulders and right/left elbows）, and investigate differences between linear and nonlinear measurements of the associated joint motions and differences in the local stability between the upper and lower extremities. This attempt involves the calculation of a nonlinear parameter, Lyapunov Exponent （LE）, and a linear parameter, Range of Motion （ROM）, during treadmill walking in conj unction with a large population of healthy subjects. Joint motions of subjects were captured using a three-dimensional motion-capture system. Then mathematical chaos theory and the Rosenstein algorithm were employed to calculate LE of joints as the extent of logarithmic divergence between the neighboring state-space trajectories of flexion-extension angles. LEs computed over twenty males and twenty females were 0.037~0.023 for the neck, 0.043＋0.021 for the right shoulder, 0.045i0.030 for the left shoulder, 0.032i0.021 for the right elbow, and 0.034~0.026 for the left elbow. Although statistically significant difference in the ROM was observed between all pairs of the neck and upper extremity joints, differences in the LE between all pairs of the joints as well as between males and females were not statistically significant. Between the upper and lower extremities, LEs of the neck, shoulder, and elbow were significantly smaller than those of the hip （-0.064） and the knee （-0,062）. These results indicate that a statistical difference in the local stability between the upper extremity joints is not significant. However, the different result between the ROM and LE gives a strong rationale for applying both linear and nonlinear tools together to the evaluation of joint movement. The LEs of the joints calculated from a large population of healthy subjects could provide normative values for the associated joints and can be used to evaluate the recovery progress of patients with joint related diseases.

Influence of Kinematic Analysis Parameters of Drag Anchor Trajectory Prediction Using Yield Envelope Method

Drag anchor is widely applied in offshore engineering for offshore mooring systems.The prediction of the invisible trajectory during its drag-in installation is challenging for anchor design in determining the anchor final position for ensuring sufficient holding capacity.The yield envelope method based on deep anchor failure for kinematic analysis was proposed as a promising trajectory prediction method for drag anchor.However,there is a lack of analysis on the effects of the parameters applied in the kinematic analysis.The current work studies the effects of the yield envelope parameters,anchor line bearing capacity factor and the anchor/soil interface friction.It is found that the accuracy of the yield envelope parameters has large impact on the prediction results based on deep yield envelopes.Analyses of cases with smooth fluke predict deeper embedment depth than that from analyses of cases with rough fluke.The decrease of the capacity factor results in the increase of the anchor embedment depth,the anchor line load,the anchor chain angle and the stable value of the normalized horizontal load component for the same drag length,while the stable value of the normalized vertical load component decreases when the capacity factor decreases.This illustrates the importance in applying reasonable parameters and improving the method for more reliable prediction of the anchor trajectory.

Kinematic Analysis and Rock Mass Classifications for Rock Slope Failure at USAID Highways

Rock slope kinematic analysis and rock mass classifications has been conducted at the 17^(th) km to 26^(th) km of USAID(United States Agency for International Development)highway in Indonesia.This research aimed to examine the type of rock slope failures and the quality of rock mass as well.The scan-line method was performed in six slopes by using a geological compass to determine rock mass structure on the rock slope,and the condition of joints such as persistence,aperture,roughness,infilling material,weathering and groundwater conditions.Slope kinematic analysis was performed employing a stereographic projection.The rock slope quality and stability were investigated based on RMR(rock mass rating)and SMR(slope mass rating)parameters.The rock slope kinematic analysis revealed that planar failure was likely to occur in Slope 1,3,and 4,the wedge failure in Slope 1 and 6,and toppling failure in Slope 2,5,and 6.The RMR rating is ranging from 57 to 64 and can be categorized as Fair to Good rock.The SMR rating revealed that the failure probability of Slope 3 was 90%,while it was from 40%to 60%for others.Despite the uniform RMR for all slopes,the SMR was significantly different.The detailed quantitative consideration of orientation of joint sets and geometry of the slope contributed to such differences in outcomes.