Applied Mechanics and Materials Vols. 365-366

Abstract: The open arc welding robots have been used widely nowadays; however, the elastic deformations of every inner link inevitably affect the welding quality. In this paper, it proposes an effective method of service reliability assessment for the rigidity-flexibility coupling open arc welding robot. Firstly, a parametric virtual model of the robot is built in ADAMS/View-AutoFlex module. Secondly, the stochastic errors generated in the working process are simulated by a program created from pseudo-random numbers which have been written by multiplicative congruence method. Lastly, Monte Carlo sampling calculation is implemented for the virtual model, and large sample data of the dynamic characteristics in welding process are obtained and used to calculate the service reliability of the welding robot. This method includes simplicity (no need to solve complex mathematic model) and high accuracy which make it highly promising for application in mechanism design.

Abstract: In this paper, five controllers including linear and nonlinear ones for an underactuated overhead crane are derived based on the passivity of the system. The total energy of the system and its square are used in Lyapunov candidate function to design controllers. The equilibrium point of the closed loop is proven to be asymptotically stable by the Lyapunov technique and LaSalle invariance theorem. In addition, the optimal linear controller is also combined to force the swing angle to converge fast to zero by reaching destination of the trolley. Numerical simulations are carried out to evaluate the controllers.

Abstract: After the coal-mine accident, to get information of the coal-mine accident has become the key of disaster rescue and relief, and after disaster, the environment is very bad, the rescue-workers cant arrive at the scene of the accident to obtain information at the first time, so the coal-mine rescue robot was brought into being, it can reach the place where the person hard to go to implement the detection of information and rescue. This paper introduces the research status of coal-mine rescue robot. According to the different methods of navigation, this paper explained the research progress of the methods for robot navigation, and made a summary and prospect for its potential applications and future research work.

Abstract: This paper describes an unconventional structural layout design of aerial robot. A double-layered # shaped configuration is proposed to meet the requirements of decoupling control of eight-rotor aerial robot. Based on the modular design concept, structure design for manufacturing is combined with aerodynamic analysis to improve the level of integration of design and manufacturing. Results of manufacture and flight test show that our design on aerial robot is effective.

Abstract: Along with the increasing of structural parameters of a rotary machine, the flow induced excitation on the rotor will significantly increase. By taking two-control-volume model for sealing force, the nonlinear dynamic equation of rubbing rotor foundation was derived. Then, the problem of controlling the chaotic response of the nonlinear rubbing rotor was studied by the adaptive control theory. Numerical simulations on the rotor system were performed with a multi-parameter adaptive algorithm. The numerical results show that the parametric adaptive control method is effective to suppress a chaotic response once happened into a required steady state periodic response. This control strategy is helpful to rotor system design and maintenance.

Abstract: Continuous Passive Motion (CPM) has been confirmed as an effective clinical therapy for finger neurological rehabilitation. In this study a finger rehabilitation training robot is designed based on CPM rehabilitation theory. This paper presents the design and simulation of the finger rehabilitation robot. Based on the finger structure and movement trajectory analysis, OPTOTRAK CERTUS motion capture system is used to acquire trajectory parameters of normal human finger movement. Atlas method is employed to accomplish mechanism dimensional synthesis of the finger rehabilitation training robot. The feasibility of the mechanism is verified using a modeling and simulation method with SIMULINK software.

Abstract: Ultra-high pressure water jet ship rust is one development direction of ship rust removal technique. In order to ensure the normal working of the system, how to control each equipment is the key-part of the design. This study presents the analytical research on hardware technology of the control system of ultra-high pressure water jet ship rust system, the analysis of the principle of frequency control system and circuit design and control circuit of PLC, by analysis the structure and principles of ultra-high pressure water jet rust, and then demonstrates through experimental test that the hardware electronic circuit works properly.

Abstract: In this paper, the terminal sliding mode (TSM) control technique is used to solve the solution sought for the maximum power point tracking (MPPT) of wind energy conversion system. In order to realize the control strategy, the wind energy conversion system (WECS) is regarded as a part of the constructed high order system. Based on the constant tip-speed ratio (TSR), selecting the appropriate state variables and treating rotational speed as the object researched, the control scheme for the MPPT of wind turbine can be achieved by using the terminal sliding mode control technique. The simulation carried out shows that the system tracking efficiency can be greatly improved and the power factor and tip speed ratio are very close to the optimal value in this solution.

Abstract: Aiming at the difficulties to establish dynamic models of industrial robots, a novel fuzzy PID controller based on product strategy was presented. Membership degrees was determined according to position error and error change. Meanwhile, parameters of the fuzzy-PID controller would be tuned by the varied factors calculated from the membership degrees based on product strategy. Considering disturbance of friction, feedforward based on Stribeck model was introduced. Compared with traditional PID controller, experiment of manipulator demonstrates better effectiveness and robustness of the controller. The new controller keeps tracking error within 0.4%.

Abstract: The present paper is on the experimental investigation of a potentially effective method to alleviate the strength of aircraft wake vortex. The research work was carried out in a water-towing tank which equipped with a 2-D PIV system. By using modified flaps attached to the baseline-airfoil, the Rayleigh-Ludwieg instability of the wake vortex was activated, resulting in a premature dissipation of the wake vortex. The experimental results of PIV measurement exhibited that the circulation of the wake vortex was reduced to over 50% for the optimal case at 45 wingspans downstream with suitable settings, which proved the effectiveness of the modified-flap treatment in alleviating the wake vortex under labor conditions.