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To improve the carrying capacity of the robot, reduce the energy consumption of the driving motor and make the wheel-leg mode switching smooth and efficient, a reconfigurable decoupled parallel mobile robot configuration is proposed, and the configuration synthesis research and decoupling and singularity analysis are carried out. According to the expected degree of freedom of the robot's mechanical leg, four main motion limbs are synthesized. The 58 constraint limbs are synthesized based on the de-constraint method of the screw theory. Based on the virtual chain method of the screw theory, the 3R spherical parallel mechanism is synthesized as the bearing limb of the mechanical leg. Then two robot examples are given. Taking one of the robots as an example, the input-output equation is established, and the decoupling of the mechanical leg is analyzed. The singular configuration of the reconfigurable unit is verified by the reduction to absurdity, and the singular type is judged based on Grassmann line geometry. Finally, the influence of the singularity of the bearing limb on the motion output of the mechanical leg is analyzed. The mechanical leg of the robot adopts a parallel limb chain configuration, which has strong bearing capacity. The robot realizes wheel-leg switching based on constraint singularity, which makes the switching action more stable. The configurability of the mechanical leg reduces the energy consumption of the drive motor. Each drive of the mechanical leg is decoupled from the other, which reduces the control difficulty and makes the wheel-leg mode switching of the mechanical leg more efficient.

A 4-CPS/UPU parallel mechanism used in the field of parallel machine tools is proposed. Based on the screw theory, the kinematic and constrained screw system of the parallel mechanism is established. The mechanism has five degrees of freedom and can realize the function of three shifts and two rotations. The degree of freedom is verified by the modified K-G formula. The forward and inverse solutions of the parallel mechanism and the working space are analyzed. The simulation analysis is carried out by Adams software. The workspace of the mechanism is continuous without cavity, and its shape is similar to that of a pyramid, which is regular and symmetrical; the smooth displacement and velocity curves obtained by simulation show that the mechanism has good kinematic performance, which provides a certain theoretical basis for its parametric design in the field of parallel machine tools.

A station in the Chinese Baijiu box packaging production line has a height difference between the two production lines due to the workshop layout, and the height difference will increase the defective rate of the Chinese Baijiu box base of the station. Aiming at the problem of high defective rate, a 1R2T parallel mechanism is proposed in this research. Based on the screw theory and screw reciprocity principle, a variety of parallel mechanisms that can meet the needs of the station are synthesized. According to the field working conditions, a 2RPS-RPR parallel mechanism is designed, which can realize the 1R2T function and has three degrees of freedom. The inverse solution analysis and workspace description of the parallel mechanism are carried out, and the three-dimensional model of the parallel mechanism is drawn according to the layout of the production line. The rationality of the mechanism motion is analyzed. It is obtained that the combination of configuration design based on the screw theory and actual working conditions is a very effective theoretical analysis method.

A novel hybrid dual-platform staggered hexapod robot based on R&(2-UPU/2-RPR) hybrid mechanism is proposed, and the structure of the robot is designed. The hexapod robot relies on the mutual dislocation of the upper and lower platforms of a 2-UPU/2-RPR parallel mechanism to generate the walking action. The parallel mechanism is also used as a body connecting two groups of three legs, so that the robot can achieve “3+3” gait walking with less driving. The body of the hexapod robot is connected in series with the loading platform by a relative rotation structure, which can realize 360° flexible turning with zero radius. The inverse position solution of the parallel mechanism is obtained based on the RPY transformation matrix. The maximum step length, the maximum zero radius turning angle of a single turn in an intermittent period of the hexapod robot and the trajectory curve of the hexapod robot are obtained by analyzing the mutual interference constraints of the legs and driving constraints of the hexapod robot. The gait of the hexapod robot walking on flat ground and climbing steps is analyzed. Finite element analysis results on its load capacity show that the hexapod robot can replace the porter and has a wide range of potential applications.

Aiming at the ankle rehabilitation and training of stroke patients, an ankle rehabilitation mechanism with 3R1T sports performance is proposed. The screw theory is used to analyze the degree of freedom, the closed vector method is used to solve the inverse position solution, and Adams is used to simulate the kinematics of the hybrid mechanism. The maximum rotation angle error of the mechanism during dorsiflexion and toe flexion is calculated. The results show that under the displacement-restriction device, the mechanism can complete the rehabilitation movement and vertical joint traction movement required by patients within the safe range of ankle movement.

In order to overcome the shortcomings of the parallel mechanism used in express delivery industry， such as small motion space and limited application scope，a 2 （2-UPR+RPU） series-parallel hybrid mechanism is proposed based on the 2-UPR+RPU low-DOF parallel mechanism. The inverse position solution and workspace analysis are carried out in order to be applied in industrial production. Firstly，the hybrid mechanism is modeled in SolidWorks，and its degree of freedom is obtained by analyzing the screw theory. Then，the position inverse solution of the mechanism is solved by continuous method. Finally，the motion simulation is carried out in SolidWorks by using CAD variable geometry method and the track data of the processing points are obtained，and the workspace is obtained by using Matlab software. The workspace of 2 （2-UPR+RPU） hybrid mechanism is much larger than that of single-layer parallel mechanism，and its shape is regular and symmetrical. The 2（2-UPR+RPU） hybrid mechanism has both the flexibility of series mechanism and the high rigidity and precision of parallel mechanism. Through corresponding program control，it can replace manual work.

The judgment of the rigid subchain is a difficult problem in the synthesis of kinematic chain.By analyzing the kinematic chain of each closed loop in the kinematic chain,a method is proposed to determine whether there is the rigid subchain in the kinematic chain. According to the composition of the basic loop of the kinematic chain,the method of establishing the basic loop matrix is proposed. Through the operation of the basic loop matrix,the combined closed loop in the kinematic chain is obtained. The rigid subchain in the kinematic chain is got by combining the rigid subchain identification method. By the operation of the basic loop matrix,the closed loop of the rigid subchain is eliminated,and the kinematic chain without the rigid subchain is obtained. Finally,computer programming is used to realize the automatic recognition and elimination of the rigid subchain.

The wheel-legged robot has the advantages of fast moving velocity of wheeled robot and strong passing obstacle capability of legged robot,and it is the development direction of new type mobile robot. A kind of wheel-legged mobile robot based on 3-PUU parallel mechanism is presented. It has advantages of simple structure,high stiffness and strong carrying capacity. The leg walking gait of 3-PUU wheel-legged mobile robot is analyzed. The wheel and leg switch principle and the steering principle under wheel type mode are explained.The stability of robot moving on the road surface is analyzed according to the calculation of gravity,and the maximum step is determined. The trajectory equation is derived by using three spline interpolation and the variation rules of displacement,velocity and acceleration are obtained by using Matlab software. The simulation results show that the robot can achieve continuous and stable walking. The robot can be used in the rescue tasks such as underground coal mines and other dangerous environments.

A method for solving the forward kinematics analysis of parallel mechanism based on BP neural network is presented. According to the algorithm of BP neural network,three layers forward neural network is adopted. The inverse kinematics solution of the mechanism can be obtained by establishing the rotation matrix of3-CRS/SP parallel mechanism. It can be used as input of neural network and the dynamic platform position including four parameters can be regard as the output,then neural network can be trained. The simulation and experimental results show that the method is fast and effective for solving the parallel mechanism forward kinematics,and it is intuitive and simple compared with the analytical method. It can provide numerical reference for the control process of parallel mechanism.

The degree of freedom of the 3-CRS/SP parallel mechanism is analyzed by using the screw theory,the distribution of degree of freedom of the mechanism is determined,the result is verified by the modified G-K formula. And the inverse position solution of the parallel mechanism is got through the method of analytic geometry,the length between the three vertexes of the moving platform is regarded as the restrict condition to construct the constrained equations,the positive solution of all positions under the closed solution of the mechanism is studied. Finally,the appropriate motor is added to the mechanism,the boundary points that the intermediate branch chain in different lengths are searched,and the reachable workspace diagram of the mechanism is drawn by the MATLAB software.

In order to overcome such shortcomings as great inertia and small workingspace existing in parallel mechanism,the flexible cable is adopted as the traction element of parallel mechanism to take place of connecting rods. Meanwhile,the design concept of flexible cable parallel mechanism is also introduced. With the combination of them two,a new configuration of parallel mechanism driven by the rigid-flexible coupling is put forward,which brings the advantages of the two mechanisms into full play to improve the performance of the new configuration. It possesses not only the merits of high rigidity,high precision and high load capacity of the parallel mechanism but also the advantages of low weight which is possessed by flexible cable. Besides,the freedom from the limitation of hinge angle increases the workingspace of the mechanism.

A new kind of orthogonal 3-DOF 3-CPR parallel mechanism which can realize three-dimensional translation is proposed. The virtual prototype of 3-CPR mechanism is established,and the kinematics simulation experiment is carried out by using ADAMS software. The experiment shows the mechanism has good kinematics performance. The workspace of the mechanism is solved by using search method. The workspace volume of the mechanism is optimized by using genetic algorithm. The size parameters of the mechanism are obtained when the workspace volume takes the maximum value. The 3-CPR parallel mechanism has the advantages of simple structure,high stiffness,large output force,large workspace,and so on,because of using the prismatic pairs as the driving pairs. The results of the workspace optimization have important reference value for the application of the mechanism.

According to the structure and layout of less DOF 2-RPU/UPU parallel mechanism,it is overconstraint. The 3-dimensional model of the mechanism is established in Pro/E. By using the screw theory,the DOF analysis of freedom of this mechanism is carried out. The inverse position solution is obtained by mechanism space coordinate transformation. Finally,the workspace of this parallel mechanism is solved by using Simmechanics toolbox in MATLAB.

The reachable workspace of 2- RPR + RRP spherical hybrid mechanism is researched. Firstly,the degree of freedom of the mechanism is solved by the modified Kutzbach- Grvbler formula,the degree of freedom of the mechanism and the motion characteristics of moving platform are obtained. Secondly,taking the geometric relation of mechanism as the constraint condition and combining with the rotation matrix,the mathematical model of the closed positive solution of the kinematics position of the mechanism is established. Finally,according to the positive kinematics solution model,the Matlab software is used to draw up the workspace of the reference point in the specific condition,and the reachable workspace of the same conditions is verified by using the Solid Works simulation software. The correctness of the positive solution model is proved,a theoretical basis for the further analysis and optimization of the mechanism is provided.

A new type of 3-PPR spherical parallel mechanism is proposed.Due to the mobile pair special trajectory in each branch chain,the mobile pair can be equivalent conversion for revolute pair.Based on screw theory,each branched chain motion screw system is given.The mobility of this mechanism is analyzed firstly with the amendment G-K formula,The numbers of degrees of freedom is obtained.Secondly,by using the solution method of inverse spiral system and matrix theory knowledge,under the premise of Jacobian matrix of the 3-PPR spherical parallel mechanism is solved,the rank of matrix is analyzed,the singular configuration conditions and the type of singular configuration of the mechanism are obtained.In the end,according to the forward kinematics solution and interference condition,the Matlab software is used to draw up the stable working space.Research shows that a 3-PPR parallel spherical mechanism singularity is less,and easy to avoid,has good application prospect.

A novel 3T2 R redundantly actuated hybrid mechanism is proposed. First,the motion principle of realizing the three- dimensional translational and two- dimensional rotation motion of this mechanism are analyzed by using the screw theory. The DOF of this mechanism is calculated,and the driving joints are chosen and discussed. Then,the inverse position solution equation is established by using analytical method. Next,based on the inverse position solution and combining with the constraints condition of this mechanism,its workspace is studied by using the numerical search method,and performance superiority of the mechanism is analyzed. At last,the inverse position solution equation is solved by using MATLAB and the results simulation verification is carried out by using ADAMS,and the correctness of the inverse position solution model and the realizability of the mechanism are verified.

The mechanical system movement scheme design and selection is the key step in the design of mechanical system. The method for innovative design of mechanical system is proposed based on TRIZ（ Theory of inventive problem solving） and FAHP（ Fuzzy analytic hierarchy process）. According to the mechanical system performance index,the correlation matrix of the performance index and the engineering parameters of TRIZ are constructed. The solving procedure of conflict matrix of mechanical system is proposed. Aiming at the fuzziness and uncertainty of the mechanical system movement scheme evaluation,through constructing the fuzzy membership functions to select and evaluate,The validity of the method is verified by an example.

A novel 2- UPS + 2- RPU over- constraint parallel manipulator（ PM） is proposed. The two RPU legs of this PM provide four constraints whereas two of them are over- constraints due to the particular arrangement of the joints in RPU legs. Firstly,the constraint forces are analyzed on the basis of the screw theory and the velocity constraint equation of this PM is established,and based on this,the degree of freedom of this PM is analyzed. Secondly,the geometric constraint equations of this PM are established,and the inverse displacement analysis model is provided by using analytical methods. Then,the elastic deformation of the limb is analyzed with the limb constraint wrenches based on calculating deformation and superposition principle at small strain,and the stiffness matrix of the limb constraint wrenches is defined. Finally,the relationship between outer loads and both the line displacement and the angle displacement of the moving platform is set up,and then the matrices of flexibility and stiffness are obtained. It is found that the constrained force / torques have a major influence on the stiffness and elastic deformation of limited- DOF over- constraint PMs,and the elastic deformation are mainly in the axial direction of the constrained force / torques.

Abstract Taking the controllable 5R planar parallel mechanisms（ PPM） as the study object,combining its engineering application,the kinematic model is established,and the full-information parameter modeling method of configuration transformation and movement characteristic analysis integration is proposed.Based on the bottom-up configuration design method,the model of bar-pair,kinematic sub-chain,main configuration are established. Through the variable drive layout,parameters configuration mode,the new configuration is transformed,the purpose of rapid reconstruction design of configuration and the simplified kinematics solution is achieved. The contrastive analysis of the output trajectory tracking before and after the drive layout configuration transformation is carried out,the result shows that the workspace is expanded. Through designing the experiment device,the effectiveness of solving the workspace by trajectory tracking method is verified.

The motion analysis of 3- RRS spherical parallel mechanism is carried out by using the screw theory. The forward kinematics of 3- RRS spherical parallel mechanism is solved by using Newton iterative method. The inverse kinematics model of 3- RRS spherical parallel mechanism is established by using closed loop vector method. The corresponding inverse position solution formula is derived. Eight sets of inverse solutions are obtained. Through the example analysis,the validity of the position solutions of 3- RRS spherical parallel mechanism is verified. The reachable workspaces of 3- RRS spherical parallel mechanism are solved with the help of numerical search method. The reachable workspace diagrams with different structure parameters are drawn by using Matlab software. The variation law of the workapaces is analyzed. The results lay the foundation for the application of 3- RRS spherical parallel mechanism.

A kind of 3-DOF planar parallel mechanism which has two translational and one rotational is introduced.Firstly,the position and posture analysis of the parallel mechanism is conducted,its positive and inverse solution equations are established,and then the position positive and inverse solution are solved.Secondly,by using the MATLAB to calculate a group of experimental data,the results can be used to test the correctness of equations.At last,according to the positive and inverse solutions equations,the velocity and acceleration of mechanism input and output are solved.The results show that the structure of 3-PRP mechanism is simple and also can be easy to control and drive,meanwhile,the researching results established a certain theoretical basis for the performance research on the mechanism such as workspace,trajectory planning and optimum design.

The kinematics characteristic of the closed chain two degree of freedom planar five-bar mechanism is analyzed by using the closed vector polygon projection method,complex number-vector method and matrix method.The kinematics equations are deduced,furthermore,the characteristic and application situations of each method are compared and analyzed.The kinematics equations are validated according to the example designed.By using the Solid Works motion simulation software,the motion path is changed with the original position of driving link,and the inner link between kinematics equations and output motion path is achieved.The reference for solving kinematic characteristic of hybrid driven mechanism in analytic method can be provided.

By using the method of closed vector,the position positive solution model of the symmetrical planar 3- RRR parallel mechanism is built. Aiming at the typical example（ for the frame is the longest and all the rods connecting frame are cranks）,with the help of the numerical method to solve and the reachable workspace of 3- RRR parallel mechanism is mapped by using the Matlab,and compared with the result gained by motion simulation of virtual prototype software Solidworks.