Applied Mechanics and Materials Vol. 487

Abstract: An efficient and practical controller was designed, which achieves high performance for a BLDC motor. Actual hardware experimental platform was established. Double-closed loop control scheme using PID algorithm is presented and applied into the system successfully. Through the tuning of PID parameters, the start and stop of motor is fast, current fluctuation is small, and the actual speed of operation is consistent to the set speed, the error of stability maintains at 10r/min or less. The experiment result shows the BLDC control system operates smoothly, and it has high reliability, robustness.

Abstract: This paper elaborate a design of a new small simple 6-axis robot arm. The design not only can verify the 6-axis motion algorithm, but also have a better property of the economy and the easy-handing. In the mechanical aspect, using the connection method of the single aluminum plate reduce the load effectively. In the control aspect, using stepper motor driven system reduce the cost. This design has a high application value in the process of mechanical arm development.

Abstract: The structure and working principle of the hydraulic steering by-wire system were described, and the optimal control algorithm of the system was obtained by the comparative analysis. Fuzzy control was chosen as the steering systems control algorithm, and it can realize closed-loop control of the front wheel corner. Matlab/Simulink was used for the simulation of the entire system. The simulation got the fuel tank displacements response curve, and verified the accuracy of the system design, which can provide a reference to the design of tractors steering system. Bench test was proposed to verify the accuracy of the system. The bench test results showed that the hydraulic steering by-wire controller can realize systems steering function well, and the system improved the control accuracy and fast response characteristics.

Abstract: For the problems that exist in EPS composite test-benches, PID control laws are expounded, a composite PID controller is designed, which is integrated with multiple advanced PID control algorithms (variable-integral PID algorithm, PID algorithm with filters, partial derivative PID algorithm, PID algorithm with dead zone), and it is simulated by MATLAB. The simulation results show that the improvement of accuracy and the impacts mitigation of the nonlinearity and external electromagnetic interferences are achieved well through the composite PID controller, and there is practical significance.

Abstract: As we all known, for a certain product, inspection reliability for the product can be considered and calculated by a famous reliability index as POD (Probability of Detection). While, for a batch of product, Stat. character should be added into POD because one-by-one inspection always is not economic, and POD without any consideration of Stat. character is not used directly for inspection reliability of a batch of product. So, inspection reliability for a batch of products can be considered and divided into reliability of inspecting objective (could be defined as POD) and reliability induced by sample inspection (R_s). In this present paper, inspection strategy based on sample inspection reliability is considered, together with some factors influent to R_s is analyzed such as sample size, producer risk and consumer risk, acceptable quality level (AQL), rejectable quality level (RQL).

Abstract: This paper presents a novel parallel tri-axis force sensor with decoupled feature, and performs its performance analysis. Firstly, the structural characteristics of the parallel tri-axis force sensor are introduced and the stress distribution of each limb elastomer is analyzed. To measure the transformation relationship between the force and strain, the electric bridge is formed by pasting strain on the elastic-sensitive element. Then, the finite element simulation of the elastomer is conducted and performance analysis of the sensor is carried out, which shows that the parallel tri-axis force sensor is decoupled, linear and fully-isotropy. The sensor possesses good static performance and can meet the requirements of tri-axis force measurement in general industrial production. The contents of this paper riches the structure type of the multi-component force sensor and will be useful for the research and development of the parallel force sensor.

Abstract: In the field of professional pilot training, flight simulator is becoming increasingly important, which draws more and more attention nowadays. For effectively guiding and assessing the training quality of pilots while being trained, the system needed to record the video of the flight data from monitors without bringing any changes to the flight simulator. The system extracted the frames from the video and then the images would be processed through binarization. So we could easily recognize the flight data from the binarization images by using the pattern recognition technology. Thus the flight track could be reconstructed in three dimension based on the OpenGL API, which will be very beneficial to the training. Altogether, the system can take advantage of the resources to guide and assess the training process of pilots more efficiently as well as developing the pilot training industry.

Abstract: Hydrodynamic coefficients of solar underwater glider robot are one of the important indicators to measure its maneuverability. Based on solar underwater glider robot, using ANSYS CFX software simulate analysis, and through the MATLAB data fitting to body hydrodynamic coefficients. Drawing hydrodynamic coefficient curves for the robot is the critical study of underwater robot hydrodynamics, its shape optimization for subsequent theoretical data is important.

Abstract: The formation of burr is a common phenomenon in metal cutting, its formation and variation directly affects processing quality and production efficiency of the workpiece. It is one of the key technologies which were applied in precision or super-precision manufacture and automatic processing. Burr expert system is not only a communication platform between burr formation mechanism and burr removal technology, but also an important channel that promote the development of burr-free cutting technology. It was highly concerned by mechanical engineering experts and scholars at home and abroad. This study develops neural network (NN) metal cutting burr expert system with network function, facing the application of burr removal technology, making use of neural network technology and expert knowledge system technology, and closely integrating experimental study of metal-cutting burr. Combined with milling, the study on prediction burr sizes using the system is carried out. The results show that the predicted results and the experimental results are in good agreement, which demonstrates the system is feasible and effective.

Abstract: Aiming at on-orbit capture task, a Genetic Algorithm based approach for pre-collision trajectory optimization with multi-targets is proposed in this paper. Through the analysis of task characteristics, multi-targets before collision are presented, which contain the point-to-point manoeuvre, impact pose control and impact impulse minimization. Genetic algorithm is employed to optimize the pre-collision trajectory after integrating multi-targets by setting task weight. At last, the simulation results verify the effectiveness of the proposed method.