Applied Mechanics and Materials Vol. 483

Abstract: Through the establishment of a five-degree-of-freedom vehicle model, calculating and analyzing the seat vertical acceleration, wheel ground adhesion index and the wheel dynamic load for the car with different speeds that runs over road humps having different height and width, so as to obtain the effect of height and width of the hump on the deceleration performance and driving safety. According to the comparative analysis of the seat acceleration, wheel ground adhesion index and the wheel dynamic load, so as to obtain the best speed limit range of the road hump.

Abstract: Based on 1,3-propanediol production from continuous fermentation of glycerol by Klebsiella pneumoniae, the dynamic behaviors of a kinetics system with continuous time-delay are analyzed. At first, a six-dimension kinetics system concerning the intracellular substance is proposed by introducing weak nuclear continuous time-delay into the specific cellular growth rate. Second, taking the inverse of average time-delay as parameter, the local stability of the positive equilibriums and the existence of Hopf bifurcation are discussed. Finally, the period solution of biomass and the parameter region of Hopf bifurcation are pictured numerically taking some special number in substrate concentration in feed medium and dilution rate.

Abstract: To meet the requirement of smooth convey for light, thin and small product in modern industrial area, a new type of vibratory feeder activated by the bimorph vibrator was proposed in this paper. The dynamic model of bimorph vibrator was established by analyzing the working principle. A prototype of the piezoelectric vibratory feeder was produced and tested. The relationship among voltage, amplitude, frequency and feeding speed was obtained from the experiments. The experimental results show that the proposed vibratory feeder had good performance at resonance. The amplitude and feeding rate increase linearly with voltage. The proposed vibratory feeder will have wide prospects in the automatic assembly line.

Abstract: Living creatures can walk or run more elegant and advanced than any other legged mechanical models. Principles of existing robot systems are based more on technical rather than on biological concepts, yielding unstable locomotion with low speed. In order to apply advanced biological phenomena to the mechanical model, three types of vertebrates are selected, and their structures are modeled by 13 links and 12 joints, covering all existing leg and body arrangements, which is a rigid multi-body system and simulated to obtain optimal conditions by calculating locomotion efficiency, which satisfy the principle of minimum energy expenditure.

Abstract: In this paper, a new systematic approach for designing a self-tuning controller for an autonomous quadrotor robot is introduced.In order to design the self-tuning controller, first, a linearized dynamic model of a quadrotor about hovering positions is derived, and thenthe successive loop closure approach is applied to design the self-tuning PID controller of the attitude, altitude and velocity for the autonomous flying capability of the flying robot. In addition, nonlinearities of the design model are also imposed in the control loop by takinginto account the saturation of actuators. For the verification of the effectiveness of the proposed controller, various simulation studiesare carried out in terms of the accuracy and robustness.

Abstract: The multi-channel joint position detection system of measuring arm is of high precision, multi-channel and other special characteristic. This system uses hardware called DSPic30F microchip as the processing core. The detection system adopts optical encoder as joint angle sensor and orthogonal decoding and reversible chip HCTL-2032 to multi frequency the detected signal, which greatly reduces the system error and enhances the detection precision. Experiments of joint position detection are realized. Thirty times repeated experiments show that the maximum error is 0.009 °and the maximum relative deviation is 40.9 × 10-3 /%.

Abstract: The FPGA is applied to the Extreme Ultraviolet camera (EUV) in the emerging aerospace applications. Firstly, the imaging principle of the EUV camera is analyzed, and the FPGA type is selected. Secondly, the data collection module is designed and the original data correction and coordinate conversion algorithm is researched. Finally, the simulation results indicate that the method which is used for this paper greatly improves the dependability and stability at the cost of the small speed loss.

Abstract: In order to guarantee work security and extend the life span of ropes, it is required that anti-twist ropes used in tensile stringing receive grease protection in time. However, the extra grease on the ropes should be recycled. Then, a grease removing and saving device was designed for such purposes by using an air wipe. It is believed that air wipe is better than other tools in grease removing because of its powerful function. To fully realize the grease removing function, we designed mechanisms to accurately position wire rope and prevent collisions between the rope and air wipe, calculated air consumption and supply pressure and designed a pneumatic control system. The device works well in practice, and the applications showed that the removing process was simple and the amount of the removal grease is easy to control.

Abstract: In order to improve the service life of wire rope used n tensile stringing, an automatic cleaning, detection and maintenance integration system was designed. Through the simulation analysis of elastic plates that fix the fixed brushes and the design of the rotating brushes driving system, a wire rope decontamination device assembled fixed brushes and rotating brushes was developed according to the demand of steel wire decontamination. The brush head adopts the design concept of elastic device, which makes the wire rope pressing force adjustable, ensures the wire connectors passable and makes the axial dirt sweeping of different diameter wire rope possible. The overall rotation mechanism with multiple brushes can circumferentially sweep the dirt in the wire rope gap. Then, the wire ropes were comprehensively sweeped with no dead cleanup. The device has been actually used, and the results showed that the decontamination effect is good.

Abstract: In order to improve the accuracy of biopsy, an accurate FEM model is quite essential. To get the coefficients of the puncture target material which will be used in the Abaqus FEM analysis, the paper performed indentation test on gelatin phantom which is more stable than normal biological tissue. The Neo-Hookean and the improved Kelvin constitutive model were used to describe the mechanical properties of gelatin phantom demonstrated in the tests, including the hyperelastic and viscoelastic characteristics, then least squares method was used to fit the experimental data, finally the parameters of each constitutive model were achieved, which will be used to establish the material model in the further Abaqus FEM simulation.