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This paper focuses on a new type of configuration design of a compliant parallel mechanism (CPM) planar continuum structure and its characteristic analysis of vibration-inherent frequency for planar motion, which can suppress the impact of random vibration in ultra-precision positioning and manufacturing equipment and improve the inherent frequency response of the mechanism. Firstly, a vector-mapping isomorphism between the fully CPM and conventional isomorphic parallel mechanism was constructed with a kinematic differential Jacobian matrix. Then, the mathematical model of topology optimization was put forward considering the compromise programming on the static stiffness and mean vibration-inherent frequency of the mechanism as the design variable and the minimization of compliance as the objective function. A constraint of volume fraction was considered and multi-objective micro displacement mechanism topology optimization based on a prismatic-revolute-revolute (3-PRR) planar nano-positioning continuum structure was performed using the solid isotropic material with penalization (SIMP) technique, which combines the criteria of the optimization algorithm and the vector isomorphic mapping method. Multi-objective topology optimization of the continuum structure micro displacement mechanism was investigated and presented by optimizations with different initial rejection rates. The simulation results show that the stiffness and vibration suppression performance of the continuum structure were improved, whereas the positioning of differential kinematics characteristics of the 3-PRR micro displacement planar fully CPM and isomorphic prototype mechanism retain the same. The modal analysis also provides a rational configuration for the micro displacement mechanism dimensional design and its optimal modal parameters. The crossover oscillation in frequency response of the continuum structure was reduced and quickly converged in the optimization iterations. The performance of the optimized mechanism was verified by the experiments on a planar fully compliant micro displacement continuum structure based on Lead Zirconate Titanate (PZT) actuator.

A mechanism for topology optimization of 3-DOF parallel peristaltic structure robot with vector continuous mapping matrix using Solid Isotropic Material with Penalization (SIMP) method is presented in this paper. We focus on how to prevent the differential motion consistency between parallel prototype mechanisms with peristaltic structure. As the conventional parallel robot joints/hinges are no longer needed after topology optimization, therefore, we renamed this kind of 3-DOF robot structures as peristaltic structure. In the proposed method, the vector continuous mapping matrix is built as stress/strain transfer direction conditions for topology optimization of peristaltic structure, and SIMP method is used for multi-inputs and multioutputs decided by parallel prototype mechanisms. Some numerical examples are presented to illustrate the validity of the proposed method.

By using image recognition technology, this paper presents a new fault diagnosis method for rotating machinery with artificial immune algorithm. This method focuses on the vibration state parameter image. The main contribution of this paper is as follows: firstly, 3-D spectrum is created with raw vibrating signals. Secondly, feature information in the state parameter image of rotating machinery is extracted by using Wavelet Packet transformation. Finally, artificial immune algorithm is adopted to diagnose rotating machinery fault. On the modeling of 600MW turbine experimental bench, rotor`s normal rate, fault of unbalance, misalignment and bearing pedestal looseness are being examined. It`s demonstrated from the diagnosis example of rotating machinery that the proposed method can improve the accuracy rate and diagnosis system robust quality effectively.

This paper considers adaptive control of parallel manipulators combined with fuzzy-neural network algo- rithms (FNNA). With this algorithm, the robustness is guaranteed by the adaptive control law and the parametric uncertain- ties are eliminated. FNNA is used to handle model uncertainties and external disturbances. In the proposed control scheme, we consider modifying the weight of fuzzy rules and present these rules to a MIMO system of parallel manipulators with more than three degrees-of-freedom (DoF). The algorithm has the advantage of not requiring the inverse of the Jacobian matrix especially for the low DoF parallel manipulators. The validity of the control scheme is shown through numerical simulations of a 6-RPS parallel manipulator with three DoF.

A discrete variable structure control with equivalent law is proposed to suppress vibration of a flexible cantilever beam boned with piezoceramic patch and strain gauges. The finite element method and modal truncation technique is applied to obtain the dynamic model of the structure. The vibration control of structure is considered as the issue that the controller enables the system to be zero state as the system states are away from the equilibrium one due to external disturbances, that is, it is a state regulator. The error state equations are obtained according to state equation and control requirements. The discrete variable control approach with disturbance observer is applied to design the state regulator. The discrete Kalman filtering technique is employed to construct state estimator because the state variables cannot be directly measured. The first four natural frequencies and damping ratio are obtained by using experimental modal testing. Using dSPACE real-time simulation system and MATLAB/Simulink, the control system is built and the active vibration control study is carried out. The experimental results show that the proposed controller can effectively reduce the vibration response of the structure.

The study of algorithms for active vibration control in flexible structures became an area of enormous interest, mainly due to the countless demands of an optimal performance of mechanical systems as aircraft and aerospace structures. Mode theory and linear quadratic state-feedback regulator are applied to suppress the vibration of a flexible link with piezoelectric actuators and strain gage transducer. The state-space dynamic model of the system was derived by using finite element method and experimental modal test. On the basis of the model, a Kalman state estimator is designed taking into account the uncertain disturbance and measurement noise. The disturbance and measurement noise are treated as white noise. A linear quadratic state-feedback regulator is implemented, which minimizes the quadratic performance function that trades off regulation performance and control effort. The experimental results show that the proposed controller can provide good disturbance rejection and can effectively reduce rapidly the strain of the flexible link and elastic vibration response.

A class of parallel manipulators known as Rotary Humanoid Wrist (RHW), which is actuated by six circular motors on the circular base and dose not involve any prismatic joint, is analyzed based on screw theory. Model of RHW is build by using simulink tools with constant length limbs. The mobility of RHW is analyzed and the optimal combination of the main parameters for maximizing the workspace volume of RHW is also given.

Sliding mode control had been designed for robot manipulators at presents popularly, but the chattering is also a primary factor which infected the precise of the trace tracking of robot manipulators. This paper proposed a sliding mode control combined with a low-pass filter to deduce the influence by chattering and increase the precise of the trace tracking of robot manipulators. The stability and convergence of the designed controller are proved. The effectiveness of the proposed method is verified by simulation and experiments.

A quantitative HPLC method was applied to determine the amounts of C-60 and C-70 present in extracts of soot produced in the electric arc reactor and in flames. The combustion method was found to yield a higher C-70/C-60 ratio (0.67) compared with the evaporation experiment where the C-70/C-60 ratio amounts to 0.27.

A phosphorus implant in p-type silicon was analyzed by SIMS, and both the implant profile and the matrix signal were observed to exhibit some anomalous behavior. Further studies revealed the same behavior in other implants. This phenomenon was observed when an n-type dopant was implanted into a p-type matrix, or vice versa. However, some exceptions arose, making the interpretation difficult. The use of matrix signal normalization was adopted and found to improve the results.