Chao Chen

Monash University (Australia) · Department of Mechanical and Aerospace Engineering, Clayton

The Monash Epicyclic Parallel Manipulator (MEPaM) is a three-legged six-degrees-of-freedom (dof) parallel mechanism with base mounted actuators. Due to the architecture of MEPaM, a closed form solution to the direct geometric problem was obtained. The concepts of Z-Width and transparency were used to analyse the performance of MEPaM as a haptic dev...

The Monash Epicyclic Parallel Manipulator (MEPaM) is a novel six-degree-of-freedom (dof) parallel mechanism with base mounted actuators. Closed form equations of the inverse dynamic model of MEPaM are obtained through two different methods, with simulation showing these models to be equivalent. The base inertial parameters for the dynamic model of...

Path planning for parallel manipulators in the configuration space can be a challenging task due to the existence of multiple direct kinematic solutions. Hence the aim of this paper is to define a generalised hierarchical path planning scheme for trajectory generation between two configurations in the configuration space for manipulators that exhib...

Wind speed series show unsteady and nonlinear phenomena. The accurate forecast of wind speed is important for the safety of renewable energy utilization. Compared to the prediction models which use single algorithms, hybrid models always have higher accuracy. Based on the theories of Wavelet, classical time series analysis, genetic algorithm, parti...

The analytical efficiency expression of a compound epicyclic gear train with split power is derived via the approach based on virtual power. New concepts, the split-power ratio and the virtual split-power ratio, are introduced to handle the compound gear train. The efficiency formula is verified by a particular condition. The phenomenon of self-loc...

Wind speed forecasting is one of the most important technologies to guarantee the wind energy integrated into the whole power system smoothly. In this paper a hybrid model named EMD–ANN for wind speed prediction is proposed based on the Empirical Mode Decomposition (EMD) and the Artificial Neural Networks (ANNs). To choose the best training algorit...

A new six-dof epicyclic-parallel manipulator with all actuators allocated on the ground is introduced. It is shown that the system has a considerably simple kinematics relationship, with the complete direct and inverse kinematics analysis provided. Further, the first and second links of each leg can be driven independently by two motors. The serial...

The aim of this paper is to define a process to expand the overall reachable workspace of the 5R mechanism and to conduct feasible path planning between configurations within that space, even in cases where the initial and final configurations exist in different modes. It is known that if a mechanism has multiple working modes, there is a unique wo...

This paper deals with the shape optimization of a six degree-of-freedom haptic interface device. This six-dof epicyclic-parallel manipulator has all actuators located on the ground. A regular dexterous workspace is introduced to represent the mobility of user’s hand. Throughout this workspace, the deviation of the mobile platform is bounded to prov...

The mobility or degrees of freedom is a fundamental issue in mechanisms and robotics. In this work, we distinguish the global mobility and local mobilities with different orders, and derive the corresponding conditions systematically. The relations between the global mobility and the local mobilities are disclosed. We show that the rank-deficiency...

The volume of the orientation workspace is measured based on two invariant principles: It must be invariant with respect to the ground frame and invariant with respect to the orientation description. A method which is based on quaternions and differential geometry is developed for the measurement of the volume correctly. The method is extended for...

The subject of this paper deals with the singularity analysis of a sixdof three-legged parallel manipulator for force-feedback interface. To this end, a geometric condition for the manipulator singularities is obtained by means of Grassmann-Cayley algebra; the parallel singularities of the manipulator are computed using Jacobian and Gröbner basis....

Force feedback interfaces for virtual reality are required to be “transparent”, which means that the interfaces must be light in weight but strong in stiffness. We introduced a new 6-dof parallel manipulator with such a feature. As compared to all existing 6-dof 3-legged parallel manipulators, this new system has all actuators located on the ground...

Schöenfiles Motion parallel manipulators can have wide industrial applications. However, the types of such manipulator are very few. This work utilize a recently developed technology, the pattern analysis of transform matrices, to parametrically synthesize a new parallel manipulator with Schöenfiles Motion. The patterns of transform matrices are cl...

Accurate forecasting of wind speed and wind power is important for the safety of renewable energy utilization. Compared with physical methods, statistical methods are usually simpler and more suitable for small farms. Based on the methods of wavelet and classical time series analysis, a new short-term forecasting method is proposed. Simulation upon...

In this paper, an innovative Recongurable Spherical Motion Generator (RSMG) is intro- duced to provide continuous spherical motion and force transmission. The mechanism en- ables unlimited workspace in 3-DOF spherical motion with rapid, continuous and precise mo- tion capability. The conceptual design, as well as direct and inverse kinematics, are...

A four-bar linkage being able to visit exactly up to five poses, approximate synthesis should be applied for a large number of poses. We introduce here a family of linkages for motion generation, and further derive a method to synthesize one linkage of this family, which can visit up to 11 poses exactly. Interestingly, the upper bound for the numbe...

The classic Burmester problem aims at finding the geometric parameters of a planar four-bar linkage whose coupler link attains a prescribed set of finitely separated poses. The solution proposed is claimed to be comprehensive because it (a) includes all four types of dyads-RR (revolute-revolute), PR (prismatic-revolute), RP and PP-and (b) gives due...

The classic Burmester problem aims at finding the geometric parameters of a planar four-bar linkage for a prescribed set offinitely separated poses. The synthesis related to the Burmester problem deals with revolute-revolute (RR), prismatic-revolute (PR), and revolute-prismatic (RP) dyads. A PR dyad is a special case of the RR dyad, namely, a dyad...

The Dual-Wheel Transmission (DWT) unit, an innovative driving mechanism for wheeled mobile robots (WMRs), was introduced elsewhere. In this paper we conduct the direct and inverse kinematic analysis of WMRs with such units. This analysis can be applied as well to other types of WMRs equipped with conventional wheels. Both central and offset types o...

This paper proposes a generalized transmission index for spatial mechanisms, based on the virtual coefficient between the transmission wrench screw and the output twist screw. This index is applicable to single-loop spatial linkages, with fixed output and single or multiple degrees of freedom. We show that the transmission index introduced by Suthe...

This paper reports an innovative design of epicyclic (planetary) cam trains based on pure-rolling contact, intended to overcome the drawbacks of gear trains, such as Coulomb friction and backlash. The kinematic relations of the mechanism with a given speed-reduction ratio are analyzed; accordingly, the profiles of the sun cam and ring cam, key elem...

The classic Burmester problem aims at finding the geometric parameters of a planar four-bar linkage for a prescribed set of finitely separated poses. In this paper, we introduce a Matlab-based graphical user interface to support the solution of the classic Burmester problem. The synthesis deals with both revolute-revolute (RR) and prismatic-revolut...

Abstract—A four-bar linkage can visit exactly up to five poses. Approximate approaches,can be applied on the the four-bar linkage for more than five given poses. We in- troduce here a method,to synthesize an eight-bar linkage which can visit up to 11 poses exactly. An example is given to illustrate and validate the proposed approach. Keywords:optim...

This paper proposes innovative drives for omnidirectional and quasi-omni-directional wheeled mobile robots. A novel epicyclic cam transmission is developed to transmit motion in the drives, with some advantages over its gear-train counterparts: low friction, high stiffness, and high precision. In this work, three new indices, the contact ratio in c...

The dual-wheel transmission is a novel drive for wheeled mobile robots; it provides unique features: symmetric structure; load distribution; unlimited steering capacity; and self-rotation while keeping the platform stationary. This paper discusses alternative prototypes of mobile robots with dual-wheel transmissions. We find the conditions of the d...