Papers by Author: Di Zheng

Abstract: At present, in the aquaculture environment, bait casting process of feeding machine is using time quantitative; such feeding way did not consider too much fish feeding law which will cause bait wasting and environmental pollution. An effective way to solve the problem is how to set the feeding amount through observing the fish aggregation. An intelligent bait casting method is proposed in this paper based on the machine vision technology, according to calculate the fish shoal area and shoal ratio in the feeding process. The calculate method of the fish shoal degree and flow chart of the main program is introduced. The feeding quantity is more close to the fishing bait habit. The advantage of using this method is making the bait casting more scientific and reasonable, not only saving the breeding cost, but also reducing the environment pollution.

Abstract: In order to achieve the performance of the steer-by-wire force feedback based on magnetorheological fluid (MRF) damper, an experimental system was developed. The aligning torque model and the return model based on MRF damper were built up. The general structure and hardware components were introduced. The change course of feedback force is achieved followed the change of the current of the MRF damper. Experiments showed that the force feedback system based on MRF damper can be used for automobile steer-by-wire system in the little angle.

Abstract: On the basis of compliant polishing device for aspheric, a new method of bonnet polishing on magneto-rheological of torque servo driver has been proposed. It has introduced the bonnet polishing composition and polishing principle. Polishing tool using the flexible bonnet, it can better adapt to the different curvature change of parts, and the stable polishing force can be get through MRT. Combining the constant torque device on MRF with CNC machine, this embodies high rigidity, higher precision of NC machine and reflects the MRT with adjustable, controllable, rapid response characteristics. The formulae of stress and relative velocity of polishing are deduced, and the material removal rate model has been set up. The experimental results show that this new method of bonnet polishing can provide stable polishing force, and the model is correct, has good prediction ability.

Abstract: The objective of this paper is to investigate the effect of radius of curvature on the material removal in the NC polishing of aspheric part. The models of polishing pressure and material removal rates were established based on Preston equation and Hertz theory. The material removal rates was analyzed. Experiments were carried out. Results showed that the material removal rate varies with the variations of the curvature under a constant polishing force and velocity, and the part can not be polished uniformly.

Abstract: With the development of manufacturing industry, the stroke speed of stamping machine is higher and higher. In accordance with the development, researchers and engineers have paid more and more attention to developing various types of ultra high speed stamping machines. The key to develop ultra high speed stamping machine is to solve the problem of inertia equilibrium. This paper presents an optimization approach for multi-objective inertia equilibrium design for ultra high speed stamping machine. Simulation results demonstrate the effectiveness of the proposed approach.

Abstract: Rheology is an important property of MRF (Magnetorheological fluids) and an important basis for designing a MRF device. For researchers and engineers, therefore, a practical and reliable magnetorheometer is certainly required for the study and application of the MRF and its devices. In this paper, the principle of a novel magnetorheometer was introduced, the structure and the function of major components were explained, the test process for the rheological property of the MRF by using this magnetorheometer was illustrated, the distribution of the electromagnetic field in the gap, where the MRF is filled, was analyzed by means of ANSYS software tools, and experiments were conducted to ascertain the validity of the magnetorheometer.

Abstract: This paper first establishes formulas for the total momentum of a crank-slider mechanism with weight-balancing block via kinematic analysis, and then proposes an approach for completely balancing out the inertia forces within the mechanism based the method of linearly independent vectors. The proposed approach can be used to optimize the design of weight-balancing block used in pressing machine. The approach has been verified by computer simulations.

Abstract: Aspheric parts are attracting many researchers’ attention for their excellent optical properties. The commonly used manufacturing technology for aspheric parts are mainly based on dedicated high precision machines, resulting in high cost and restricted application fields. To polish this kind of parts on general CNC machine tools, however, the surface quality improvement is limited due to the problem of force-position coupling. In order to solve this issue, a force-position decoupling control method for abrasive polishing was studied, a corresponding comliant polishing tool system was developed, and the mathematical model of the tool system was established. In addition, a polishing force controller was designed, and the performance of the tool system was numerically simulated. Simulation results showed that the polishing tool system can effectively achieve the tasks of force-position decoupling and the stable control of the polishing force.

Abstract: It is frequently reported by customers that the lower-left and lower-right wheels in the load fork mechanism of a kind of forward-type stacker designed based on static strength analysis are abraded faster than expected. In this paper, we studied by means of kinetics analysis and simulations the forces applied on parts of the fork mechanism. The simulation results show that the maximum values of instantaneous forces during operations are much higher than those derived based static force analysis, and thus explained the reason of the above-mentioned abnormal abrasion. The results also mean that static force analysis is not suitable for part strength design. Instead, one shall adopt kinetics analysis to explore the instantaneous forces in design.

Abstract: Tension control is widely used in industrial production. This paper gives one tension control method using MRF damper as the actuator. The principle of the tension generation is introduced. Through analysis and numerical simulation, the main influence factor of tension changing is obtained. The result of simulation shows that the influence factor of the tension includes the excitation electric current of the MRF damper, the radius of a wheel, rotate speed, the fluctuation of the rotate, etc. These factors present strongly nonlinearity. Through controlling the excitation electric current of MRF damper, the fluctuation of tension can be controlled to decrease.