Key Engineering Materials Vol. 621

Abstract: Precise cable drive has been developed as an alternative transmission element to gearbox, belt and pulleys, chains and sprocket in Electro-Optical Tracking system. Precise cable drive has several significant advantages including backlash free, high stiffness, high efficiency, no lubrication etc.. This paper develops analytical methods to predict the Torsional Vibration of precise cable drive to enable designers to better assess dynamic performance in the design study phase. Theoretical formulation of transmission stiffness for precise cable drive is carried out, the dynamic equation of cable drive system is deduced and inherent frequency is obtained. Parametric studies are conducted to evaluate the relationship between the inherent frequency and cable drive parameters.

Abstract: With the developing control and configuration pattern of modern manufacturing system, the complexity of manufacturing system is enlarged and the operating environment is filled with uncertainty. Under the influence of many uncertain factors, reducing delivery time, due-date performance and low inventory become the important goals of production enterprise. This paper presents a bio-inspired manufacturing system control model, combining the knowledge of manufacturing system, biological control and control system. The relationship between response time and production rate of manufacturing system with different capacity is analyzed, production capacity controller is designed using PI and PD, and the control strategy differences of production rate deviation and overshoot is also discussed. Finally, an optimized design for the parameters of a two-layer work-in-process (WIP) inventory controller is analyzed, with the reference to the neuroendocrine regulatory mechanism. The simulation analysis shows that in bio-inspired manufacturing system made of organic manufacturing cells, the shorter the response time of production capacity is, the faster its production rate responses. With the combination of two-layer WIP inventory controller and traditional PID production capacity controller, the production system is more responsive and the production offset and overshoot are small when the unexpected external demand changes of manufacturing system occur.

Abstract: A composite control scheme is proposed to solve the problems of friction toque and carrier disturbance lag in the stabilized loop of inertial stabilized platform. Based on analysis of composite control structure, the performance of single rate loop, double rate loop and composite control in the inhibition of carrier disturbance, friction torque and sensor noise are compared. In order to further verify the composite control method, an experimental setup is built. The experimental results show that: when the disturbance is 1deg-1Hz sinusoidal signal, the peak value of residual error of the single rate loop is 0.055 deg, the double rate loop is 0.031deg, and the composite control is the 0.0188deg, so the performance of isolation carrier disturbance of platform is effectively improved.

Abstract: With the increasing of market demand for finned tube and fin tube processing equipment in China continued to deepen, the problems of the inefficient study design a new type of finned tube winding machine in order to solve the traditional winding machine problem such as low efficiency and the unstable quality. Using a design method for assembly , complete design parameters to calculate the main structure of the feeding and winding device and implementing the device on three dimensional Assembly based on CATIA modeling process. Finally, to verify the overall structural design rationality, we have created a virtual prototype of finned tubes and motion simulation and the collision detection also be done.

Abstract: Winding machine is a kind of special equipment which is used to produce fin tube. At present winding machine in China mostly belongs to the semi-mechanized and semi-manual operation, with low efficiency, small size and unstable quality, which cannot meet the requirements of modern enterprise production; hence it is necessary to develop a winding machine with automatic processing ability and high precision. In this research the control system of winding parts of Aluminum strip minding machine was studied. Based on the analysis of the overall structure of winding machine control system, the hardware components, speed of running, the application of the position control system were observed. The processing parameters, the control algorithm and a module I/O assignment of TRIO motion control card were obtained. The analysis of critical point in programming conducted was realized and the control system software was designed.

Abstract: This article, to optimize the transmission mechanism of tightening machine, select the involute planetary gear with two teeth differences a research object, determine the design variables about modification coefficient, modulus and tooth thickness, based on the target of having the minimum volume, a mathematical model of optimization was established, the optimal solution of the objective function is obtained by using the SQP method on fmincon function of optimization toolbox of Matlab. The results showed, the volume of pinion decreased 15% after optimizated, the volume of the corresponding gear will also greatly reduced, achieved the optimization goal.

Abstract: Torque motor is an electrical-mechanical converter of servo valve, is bridge which connects the electrical devices and hydraulic devices, is one of key components of servo valve. The permanent magnet torque motor is studied in this paper. As key parameters of design of servo valve, the magnetic property of torque motor determines magnitude of the electromagnetic torque. At present, many manufactures of servo valve pays more attention on the test of integral servo valve. The design of torque motor also bases on experience, lacking of specialized tool for torque motor test. This paper described the principle of magnetic property of the test, developed a test system for magnetic characteristics, and established the relationship between the electromagnetic torque and current control current, and the relationship between output angular displacement and control current.

Abstract: The elevator mechanism in roller module rapid replacement system had been designed and an optimal math model had been established aiming at the maximum thrust demanded for hydraulic cylinder of the elevator mechanism is too large in this paper. In the model, installation positional parameters of the hydraulic cylinder are used as design variables; the minimum installation distance of the hydraulic cylinder, triangle position relations formed by hydraulic cylinder and design variables, and so on are used as constraint conditions; the maximum thrust of hydraulic cylinder is used as objective functions. And the model had been solved by using the MATLAB software. The case optimization result shows: the maximum thrust of hydraulic cylinder is lessened. And design purpose has been realized.

Abstract: The viscoelastic property of buffer material like sponge is an important index of material mechanics performance; it is also the main basis for choosing protective material used as hip protector. In order to research hip protector to prevent the elderly femoral fractures caused by falls, a single degree of freedom forced vibration model is adopted, and a portable viscoelasticity measurement device for sponge material is designed and developed in this paper. On this basis, the performance of the device is investigated, and the experimental research on the viscoelastic property of sponge material is carried out using the device. Investigation results show that the device has characteristics such as simple structure, light weight, and it can effectively realize the material property measurement of sponge material. At the same time, the experimental results to the viscoelasticitic property of sponge material show that the viscoelastic coefficients and usually given the performance index of sponge such as density, hardness have a close relationship. With the increase of sponge material hardness, the material's ability to resist deformation increases, so the viscoelastic coefficient also increases accordingly; but the viscoelasticity of material is also associated with the composition and the structure of the material. This research has obtained the effective method for measurement of the sponge material viscoelasticity, and found the change trend of viscoelasticity to density and hardness of sponge material, that is useful for us to select material of hip protector.

Abstract: Based on the automatic dynamic analysis of mechanical systems software, both rigid and flexible models of the space-swing mechanism for the superpave gyratory compactor are developed. The structural analysis shows that the length and the initial phase of cranks, and the assembling accuracy (coordinates) of some points are very sensitive relative to the waving of compaction angle. Greater rigidity helps stabilize the change of the compaction angles.