For the application of parallel robots in the grinding industry, a parallel robot equipped with a constant force actuator that produces a constant force for grinding is designed. To study the characteristics of the parallel robot’s spatial positions and poses, the inverse solutions of the moving platform’s spatial positions and poses as well as the workspace where objects were ground were established by using DH parameters and geometric methods. The experimental results showed that the workspace where objects were ground was a cylinder with a cross section similar to a symmetric circular sector. To analyze the characteristics of the forces produced by the parallel robotic system, the dynamics equation was established via the Newton–Euler method to verify the rationality of the force decoupling design. Theoretical calculation combined with simulation and experimental analyses confirmed the viability of the theoretical analyses which lay a theoretical foundation for the design, manufacture and control of the parallel robotic system proposed in this paper.

An algorithm for automatically planning trajectories designed for painting large objects is proposed in this paper to eliminate the difficulty of painting large objects and ensure their surface quality. The algorithm was divided into three phases, comprising the target point acquisition phase, the trajectory planning phase, and the UR5 robot inverse solution acquisition phase. In the target point acquisition phase, the standard triangle language (STL) file, algorithm of principal component analyses (PCA), and k-dimensional tree (k-d tree) were employed to obtain the point cloud model of the car roof to be painted. Simultaneously, the point cloud data were compressed as per the requirements of the painting process. In the trajectory planning phase, combined with the maximum operating space of the UR5 robot, the painting trajectory of the target points was converted into multiple traveling salesman problem (TSP) models, and each TSP model was created with a genetic algorithm (GA). In the last phase, in conformity with the singularities of the UR5 robot’s motion space, the painting trajectory was divided into a recommended area trajectory and a non-recommended area trajectory and created by the analytical method and sequential quadratic programming (SQP). Finally, the proposed algorithm for painting large objects was deployed in a simulation experiment. Simulation results showed that the accuracy of the algorithm could meet the requirements of painting technology, and it has promising engineering practicability.

The current H-type vertical axis wind turbine (VAWT) airfoils are from horizontal axis wind turbine airfoils or symmetry airfoils that are designed at one angle of attack (such as α = 6°) rather than different angles of attack. As a consequence, it cannot, to a certain extent, increase wind power efficiency. Therefore, an optimal method of H-type VAWT blade airfoils in different ranges of angles of attack is presented. It can be expressed by airfoil integrated function. Then, an optimized mathematical model in which the objective function is the average of tangential force coefficients is established. The particle swarm optimization algorithm coupled with RFOIL program is introduced to optimize the H-type VAWT airfoil profiles with high aerodynamic performance. The optimized results show that the new HVAWT-00153 airfoil is more suitable to VAWTs than the other two new airfoils and NACA-0015 airfoil. Besides, by using computational fluid dynamics technology, the superiority of HVAWT-00153 airfoil over NCAC-0015 airfoil is reviewed. The results indicate that the H-type VAWT with new HVAWT-00153 airfoils could exhibit larger torque coefficients and higher power coefficients than that of the original H-type VAWT with NACA-0015 airfoils. The maximum power coefficient can reach 0.362, increased by 8.45% compared with that of the original one. This study has a good guidance to how to design the H-type VAWT airfoils with high wind energy power.

The current design method for wind turbine airfoils and vortex generators (VGs) is independent, which cannot be used to simultaneously design wind turbine airfoils and VGs with high aerodynamic performance. Therefore, an aerodynamic-shaped integrated design method for wind turbine airfoils and VGs is proposed. The aerodynamic-shaped VGs instead of plate VGs are introduced to be installed on wind turbine blade section. The blade airfoil and aerodynamic-shaped VGs are both expressed by B-spline function. Then, the optimal mathematic model of wind turbine airfoil with aerodynamic shaped VGs is established, for which the multi-objective functions are maximum lift to drag ratio plus maximum lift coefficient. DU97-W-300 and CLARKY-117 airfoils are selected as initial objects to be optimized simultaneously by combining CFD simulation and particle swarm optimization (PSO) algorithm. The optimal results indicate that the maximum lift coefficient and lift to drag ratio of the optimized blade with novel VGs show the increase of 9.3% and 7.5%, respectively, compared to initial design. In addition, through the comparative analysis of streamlines and vorticity contours, the new blade section with novel VGs could produce larger induced vortex and could effectively restrain the fluid separation on the blade surface. This study provides a good reference to the design and application of wind turbine airfoils and VGs.