Papers by Keyword: Inverse Dynamics

Abstract: A 3-axis parallel loading mechanism, which works as a multi-axis load simulator, is proposed for reliability test of multi-axis CNC machine tools by exerting specific load spectrums on the spindle. To achieve efficient loading force control, dynamic model of the 3-DOF translational parallel robot is derived via the virtual work principle and is embedded into the control strategy to build a model-based control scheme. A mass distribution factor is introduced and the rotating inertia of the limbs is neglected to simplify the dynamics equations for better real-time control performance. This simplification method is verified by comparison with the complete dynamics model. Then the simplified dynamic model is integrated with a PI (proportional–integral) controller with feedforward to control the moving platform’s output force in the task space and this control strategy is verified through co-simulations with MATLAB/Simulink and ADAMS. Simulation results show that the proposed model-based PI controller is effective to control the three-dimensional output force of the 3-DOF translational parallel robot.

Abstract: Dynamics formulation is a primary task for dynamic optimization, control strategy design and servomotor parameters estimation of the parallel manipulator (PM). In this paper, by using the simple operation form of reciprocal screw and Lie Algebra, the compact expressions of complete Jacobian and Hessian matrix are derived. Then the inverse dynamics of 3PRS parallel manipulator is formulated based on the efficient principle of virtual work. In this model, the generalized forces of both actuation and constraint can be solved. Finally, a numerical simulation example is given to demonstrate this simple yet effective approach.

Abstract: The cut tobacco dryer is one of the most important process equipment in the cigarette production ,which is a typical process involving many factors such as multivariablity, strong coupling, time-varying and large time delay .Based on the identification of inverse dynamics, this paper establishes a process model related to some important parameters of the cut tobacco dryer which lays a foundation for optimizing the control parameters, increasing process efficiency and reducing the cost in the tobacco drying process.

Abstract: In the paper are shown one assisted method of the control orientation inertial mechanism of the small satellite. It is presented some of the general components of the small satellite and the possibility to orientation them between three axes using the inertial pulse of the electrical motors. The angular space position was determines by command of the final point and using the proper neural network to solve the inverse kinematics problem with the minimum of the errors. The precision of the space orientation position was increased by using in the proper controlling schema a direct kinematics module, direct and inverse dynamics, intelligent damper and one multiple inertial pulse method what was described in the paper. Finally was obtained one very good precision, before 2%.The neural network, the inertial pulse method, the results and the virtual LabVIEW instrumentation could be used in many other researches on the field.

Abstract: This paper focuses on the actuation strategy of an active driving simulator and its validation using experimental driving data. The simulator combines the simulation of both the road characteristics and the vehicle dynamics into a single architecture. The goal is to combine actual road excitation signals with imposed vehicle movements to create a realistic driving experience.

Abstract: 2UPS-RPU is a new 4-DOF parallel mechanism with serial input limb. In this paper, the inverse dynamic equation of this mechanism is formulated by Newton-Euler formation based on each limb and moving platform as the studying objects. The inverse kinematics of the mechanism is analyzed. The driving force, driving moment and the constraint moment can be obtained. Finally, a computer simulation is carried out to solve the inverse dynamics of the mechanism when the motion of moving platform is given.

Abstract: This paper present and validates experimentally a model-less methodology for off-line identification of modifications of nodal masses. The proposed approach is entirely based on experimentally measured data; hence no numerical modeling and tedious fine-tuning of the model are necessary. The influence of the added mass is modeled using virtual distortion forces and experimentally obtained system transfer matrices. The identification amounts to solving an optimization problem of minimizing the mean square distance between measured and modeled structural responses, the latter is based on previously recorded responses of the unaffected structure.

Abstract: In order to improve the modeling efficiency of the industrial robot dynamics control, the recursive dynamics is studied based on the Spatial Operator Algebra (SOA) theory, and the procedure realization is built in the environment of Matahematica6.0 software. The high effective recursive forward and reward dynamics for the SOA theory, has a simple math expression and a clear physical meaning. The software structure of the forward and inverse dynamics is built and the industrial robot dynamics simulation model is realized based on the integrated procedure VB.NET and Mathematica 6.0. According to the analysis, the example of PUMA560 robot forward and inverse dynamics is studied, and correctness and validity is verified by computed examples.

Abstract: The hybrid polishing kinematics machine tool (HPKMT) which is made up of “3 axes parallel + 2 axes series” is developed with the specially designed elastic polishing tool system for the polishing operation on the free-form surfaces by using the characteristic of the elastic polishing adequately by the authors. In order to control the HPKMT effectively, its characteristic of the kinematics and dynamics need be known deeply. Moreover, the problem of inverse dynamics is the theory foundation to apply dynamic control of the HPKMT. The analysis of the inverse of mechanism is the important part in the research of dynamics. On the basis of the differential equations of flexible multi-body dynamics, this paper discusses on the condition of knowing the trace, posture and velocity for the end of bodies how to solve the constraint force and constraint moment of each joint on the 3- PTT parallel mechanism and two-joint series mechanism.